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000
FXUS63 KLOT 282212
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
512 PM CDT MON JUL 28 2014

.DISCUSSION...
244 PM CDT

MAIN FOCUS THROUGH THE FORECAST PERIOD REMAINS ON COOLER THAN NORMAL
WEATHER FOR LATE JULY AND EARLY AUGUST...AND LOW CHANCE POPS FOR
DAILY DIURNAL SHOWER/THUNDERSTORM POTENTIAL.

MORNING UPPER AIR ANALYSIS DEPICTS ANOMALOUSLY DEEP EASTERN NORTH
AMERICAN UPPER TROUGH WITH AN UPPER LOW OVER CENTRAL QUEBEC. THIS
FEATURE IS PROGGED TO SLOWLY RETROGRADE WESTWARD TOWARD JAMES BAY
THROUGH FRIDAY BEFORE EVENTUALLY OPENING UP AND LIFTING OUT TO THE
NORTHEAST OVER THE WEEKEND. THIS PERSISTENT UPPER AIR PATTERN WILL
KEEP THE WESTERN GREAT LAKES REGION IN PERSISTENT COOL NORTHWEST
FLOW ALOFT...WITH SERIES OF SHEARED MID-LEVEL SHORT WAVE FEATURES
ROTATING THROUGH THE WESTERN PERIPHERY OF THE UPPER LOW. THIS
PRESENTS A DAILY THREAT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON/EVENING DIURNALLY FAVORED
INSTABILITY MAXIMA...WITH COVERAGE LIKELY LIMITED SOMEWHAT AND
TIED TO LOCALIZED BOUNDARY LAYER CONVERGENCE LINES. CURRENT
AFTERNOON GOES WATER VAPOR IMAGERY DEPICTS A WEAK MID-LEVEL SHORT
WAVE FEATURE DROPPING SOUTHWARD ACROSS WESTERN ONTARIO WHICH SHOULD
ARRIVE OVER THE AREA TUESDAY MORNING...AND MODELS INDICATE ANOTHER
SUCH FEATURE PASSING THROUGH WEDNESDAY. STRONGER HEIGHT FALLS OCCUR
FRIDAY INTO AS UPPER TROUGH RETROGRADES. GIVEN THESE CONTINUED
GUIDANCE TRENDS HAVE MAINTAINED GENERALLY LOW CHANCE POPS MAINLY FOR
AFTERNOON/EARLY EVENING PERIODS TUESDAY-THURSDAY...WITH SLIGHTLY
HIGHER POPS FRIDAY-SATURDAY WITH TROUGH OVERHEAD. TROUGH AXIS DRIFTS
OFF TO THE EAST SATURDAY NIGHT INTO SUNDAY INDICATING A RESPITE FROM
PRECIP THREAT BEFORE ANOTHER SHORT WAVE DIGS IN FROM THE NORTHWEST
ON MONDAY.

HIGH TEMPS HAVE STRUGGLED TO TOP 70 ACROSS NORTHEASTERN PARTS OF THE
FORECAST AREA TODAY...AND EVEN TO REACH THE MID 60S ALONG THE
INDIANA LAKE SHORE WITH STRONG GUSTY NORTH WINDS. DIMINISHING WINDS
AND A VERY GRADUAL MODERATION IN TEMPS ALOFT WILL HELP NUDGE TEMPS
INTO THE MID AND UPPER 70S OVER THE NEXT FEW DAYS. MORE OF A
NORTHWEST COMPONENT TO WIND TUESDAY SHOULD KEEP LAKE COOLING MAINLY
IN NORTHWEST INDIANA...AND WEAKER LAKE BREEZES OVER THE NEXT FEW
DAYS SHOULD ALLOW SHORE AREAS TO PEAK IN THE 70-75 DEGREE RANGE
MID-LATE WEEK. TEMPS NEAR 80 BY SUNDAY/MONDAY WILL AT LEAST BE ONLY
A FEW DEGREES FROM EARLY AUGUST NORMALS.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* NONE

IZZI

//DISCUSSION...UPDATED 22Z...

WINDS BEHIND THE LAKE BREEZE HAVE LARGELY SUBSIDED AND LOST THEIR
GUSTINESS...SO HAVE LOWERED WINDS SOONER IN THE FORECAST. STILL
LOOK FOR WINDS TO BECOME LIGHT AND VARIABLE AFTER SUNSET.

IZZI

FROM 18Z...

STRONG PRESSURE GRADIENT CONTINUES ACROSS THE TERMINALS WITH GUSTS
IN THE 20-25 KT RANGE ACROSS IL AND PUSHING 30 KT AT TIMES NEAR
THE LAKE MICHIGAN SHORE OF NW INDIANA. THE DIRECTION CONTINUES TO
FLUCTUATE BETWEEN N AND NNE AND WILL LIKELY CONTINUE TO DO SO
THROUGH AFTERNOON. THE PRESSURE GRADIENT SLACKENS LATE THIS
AFTERNOON SO SPEEDS SHOULD EASE BUT THIS MAY TAKE SOME TIME INTO
THE EVENING. WIND DIRECTION MAY BECOME VARIABLE THIS EVENING WITH
A LIGHT NORTHWEST DIRECTION EXPECTED OVERNIGHT. A STEADIER
NORTHWEST WIND IS EXPECTED TUESDAY. A LAKE BREEZE MAY TURN WINDS
NORTHEAST AT GYY TUESDAY AFTERNOON BUT WILL KEEP THE LAKE BREEZE
EAST OF ORD/MDW FOR NOW.

A SERIES OF UPPER WAVES WILL CROSS THE AREA THE NEXT FEW DAYS WITH
ONE WAVE PASSING OVERNIGHT POTENTIALLY BRINGING SOME MID CLOUDS.
WEAK ASCENT WILL BE IN PLACE TUESDAY WHICH MAY TRIGGER SOME ISOLD-
SCT SHRA/TSRA DURING THE AFTERNOON. THREAT IS TOO LOW TO MENTION
IN THE TAF AT THIS TIME. OTHERWISE SHOULD SEE AN INCREASE IN
DIURNAL CLOUDS.

MDB

//ORD AND MDW CONFIDENCE...UPDATED 22Z...

* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS

IZZI

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
124 PM CDT

NORTHERLY WINDS CONTINUE UP AROUND 25 KT ACROSS THE SOUTHERN HALF OF
THE LAKE EARLY THIS AFTERNOON...AND THIS IS CONTINUING TO RESULT IN
BUOY OBSERVATIONS OF 8 TO 10 FOOT WAVES. THESE WINDS WILL GRADUALLY
EASE LATE THIS AFTERNOON AND EVENING...AND EVEN BECOME WESTERLY
TONIGHT AS THE GRADIENT WEAKENS. HOWEVER...WAVE HEIGHTS WILL BE SLOW
TO SUBSIDE...WITH 4+ FOOTERS EXPECTED ACROSS SOUTHERN LAKE MICHIGAN
THROUGH MUCH OF TONIGHT. NO CHANGES ARE PLANNED TO THE CURRENT
ENDING TIMES OF THE SMALL CRAFT ADVISORIES.

FOLLOWING TODAY`S WIND AND WAVE EVENT...IT APPEARS THE WEATHER WILL
BE SOMEWHAT QUIET ACROSS THE LAKE DURING THE WEEK. AN UPPER LEVEL
LOW OVER QUEBEC WILL CONTINUE TO LEAD TO A WEST NORTHWESTERLY FLOW
PATTERN...ALBEIT LIGHT...ACROSS THE LAKE THROUGH MUCH OF THE PERIOD
AS A COUPLE OF WEAK COLD FRONTAL BOUNDARIES DROP SOUTHWARD OVER THE
LAKE.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 282212
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
512 PM CDT MON JUL 28 2014

.DISCUSSION...
244 PM CDT

MAIN FOCUS THROUGH THE FORECAST PERIOD REMAINS ON COOLER THAN NORMAL
WEATHER FOR LATE JULY AND EARLY AUGUST...AND LOW CHANCE POPS FOR
DAILY DIURNAL SHOWER/THUNDERSTORM POTENTIAL.

MORNING UPPER AIR ANALYSIS DEPICTS ANOMALOUSLY DEEP EASTERN NORTH
AMERICAN UPPER TROUGH WITH AN UPPER LOW OVER CENTRAL QUEBEC. THIS
FEATURE IS PROGGED TO SLOWLY RETROGRADE WESTWARD TOWARD JAMES BAY
THROUGH FRIDAY BEFORE EVENTUALLY OPENING UP AND LIFTING OUT TO THE
NORTHEAST OVER THE WEEKEND. THIS PERSISTENT UPPER AIR PATTERN WILL
KEEP THE WESTERN GREAT LAKES REGION IN PERSISTENT COOL NORTHWEST
FLOW ALOFT...WITH SERIES OF SHEARED MID-LEVEL SHORT WAVE FEATURES
ROTATING THROUGH THE WESTERN PERIPHERY OF THE UPPER LOW. THIS
PRESENTS A DAILY THREAT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON/EVENING DIURNALLY FAVORED
INSTABILITY MAXIMA...WITH COVERAGE LIKELY LIMITED SOMEWHAT AND
TIED TO LOCALIZED BOUNDARY LAYER CONVERGENCE LINES. CURRENT
AFTERNOON GOES WATER VAPOR IMAGERY DEPICTS A WEAK MID-LEVEL SHORT
WAVE FEATURE DROPPING SOUTHWARD ACROSS WESTERN ONTARIO WHICH SHOULD
ARRIVE OVER THE AREA TUESDAY MORNING...AND MODELS INDICATE ANOTHER
SUCH FEATURE PASSING THROUGH WEDNESDAY. STRONGER HEIGHT FALLS OCCUR
FRIDAY INTO AS UPPER TROUGH RETROGRADES. GIVEN THESE CONTINUED
GUIDANCE TRENDS HAVE MAINTAINED GENERALLY LOW CHANCE POPS MAINLY FOR
AFTERNOON/EARLY EVENING PERIODS TUESDAY-THURSDAY...WITH SLIGHTLY
HIGHER POPS FRIDAY-SATURDAY WITH TROUGH OVERHEAD. TROUGH AXIS DRIFTS
OFF TO THE EAST SATURDAY NIGHT INTO SUNDAY INDICATING A RESPITE FROM
PRECIP THREAT BEFORE ANOTHER SHORT WAVE DIGS IN FROM THE NORTHWEST
ON MONDAY.

HIGH TEMPS HAVE STRUGGLED TO TOP 70 ACROSS NORTHEASTERN PARTS OF THE
FORECAST AREA TODAY...AND EVEN TO REACH THE MID 60S ALONG THE
INDIANA LAKE SHORE WITH STRONG GUSTY NORTH WINDS. DIMINISHING WINDS
AND A VERY GRADUAL MODERATION IN TEMPS ALOFT WILL HELP NUDGE TEMPS
INTO THE MID AND UPPER 70S OVER THE NEXT FEW DAYS. MORE OF A
NORTHWEST COMPONENT TO WIND TUESDAY SHOULD KEEP LAKE COOLING MAINLY
IN NORTHWEST INDIANA...AND WEAKER LAKE BREEZES OVER THE NEXT FEW
DAYS SHOULD ALLOW SHORE AREAS TO PEAK IN THE 70-75 DEGREE RANGE
MID-LATE WEEK. TEMPS NEAR 80 BY SUNDAY/MONDAY WILL AT LEAST BE ONLY
A FEW DEGREES FROM EARLY AUGUST NORMALS.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* NONE

IZZI

//DISCUSSION...UPDATED 22Z...

WINDS BEHIND THE LAKE BREEZE HAVE LARGELY SUBSIDED AND LOST THEIR
GUSTINESS...SO HAVE LOWERED WINDS SOONER IN THE FORECAST. STILL
LOOK FOR WINDS TO BECOME LIGHT AND VARIABLE AFTER SUNSET.

IZZI

FROM 18Z...

STRONG PRESSURE GRADIENT CONTINUES ACROSS THE TERMINALS WITH GUSTS
IN THE 20-25 KT RANGE ACROSS IL AND PUSHING 30 KT AT TIMES NEAR
THE LAKE MICHIGAN SHORE OF NW INDIANA. THE DIRECTION CONTINUES TO
FLUCTUATE BETWEEN N AND NNE AND WILL LIKELY CONTINUE TO DO SO
THROUGH AFTERNOON. THE PRESSURE GRADIENT SLACKENS LATE THIS
AFTERNOON SO SPEEDS SHOULD EASE BUT THIS MAY TAKE SOME TIME INTO
THE EVENING. WIND DIRECTION MAY BECOME VARIABLE THIS EVENING WITH
A LIGHT NORTHWEST DIRECTION EXPECTED OVERNIGHT. A STEADIER
NORTHWEST WIND IS EXPECTED TUESDAY. A LAKE BREEZE MAY TURN WINDS
NORTHEAST AT GYY TUESDAY AFTERNOON BUT WILL KEEP THE LAKE BREEZE
EAST OF ORD/MDW FOR NOW.

A SERIES OF UPPER WAVES WILL CROSS THE AREA THE NEXT FEW DAYS WITH
ONE WAVE PASSING OVERNIGHT POTENTIALLY BRINGING SOME MID CLOUDS.
WEAK ASCENT WILL BE IN PLACE TUESDAY WHICH MAY TRIGGER SOME ISOLD-
SCT SHRA/TSRA DURING THE AFTERNOON. THREAT IS TOO LOW TO MENTION
IN THE TAF AT THIS TIME. OTHERWISE SHOULD SEE AN INCREASE IN
DIURNAL CLOUDS.

MDB

//ORD AND MDW CONFIDENCE...UPDATED 22Z...

* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS

IZZI

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
124 PM CDT

NORTHERLY WINDS CONTINUE UP AROUND 25 KT ACROSS THE SOUTHERN HALF OF
THE LAKE EARLY THIS AFTERNOON...AND THIS IS CONTINUING TO RESULT IN
BUOY OBSERVATIONS OF 8 TO 10 FOOT WAVES. THESE WINDS WILL GRADUALLY
EASE LATE THIS AFTERNOON AND EVENING...AND EVEN BECOME WESTERLY
TONIGHT AS THE GRADIENT WEAKENS. HOWEVER...WAVE HEIGHTS WILL BE SLOW
TO SUBSIDE...WITH 4+ FOOTERS EXPECTED ACROSS SOUTHERN LAKE MICHIGAN
THROUGH MUCH OF TONIGHT. NO CHANGES ARE PLANNED TO THE CURRENT
ENDING TIMES OF THE SMALL CRAFT ADVISORIES.

FOLLOWING TODAY`S WIND AND WAVE EVENT...IT APPEARS THE WEATHER WILL
BE SOMEWHAT QUIET ACROSS THE LAKE DURING THE WEEK. AN UPPER LEVEL
LOW OVER QUEBEC WILL CONTINUE TO LEAD TO A WEST NORTHWESTERLY FLOW
PATTERN...ALBEIT LIGHT...ACROSS THE LAKE THROUGH MUCH OF THE PERIOD
AS A COUPLE OF WEAK COLD FRONTAL BOUNDARIES DROP SOUTHWARD OVER THE
LAKE.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 281944
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
244 PM CDT MON JUL 28 2014

.DISCUSSION...
244 PM CDT

MAIN FOCUS THROUGH THE FORECAST PERIOD REMAINS ON COOLER THAN NORMAL
WEATHER FOR LATE JULY AND EARLY AUGUST...AND LOW CHANCE POPS FOR
DAILY DIURNAL SHOWER/THUNDERSTORM POTENTIAL.

MORNING UPPER AIR ANALYSIS DEPICTS ANOMALOUSLY DEEP EASTERN NORTH
AMERICAN UPPER TROUGH WITH AN UPPER LOW OVER CENTRAL QUEBEC. THIS
FEATURE IS PROGGED TO SLOWLY RETROGRADE WESTWARD TOWARD JAMES BAY
THROUGH FRIDAY BEFORE EVENTUALLY OPENING UP AND LIFTING OUT TO THE
NORTHEAST OVER THE WEEKEND. THIS PERSISTENT UPPER AIR PATTERN WILL
KEEP THE WESTERN GREAT LAKES REGION IN PERSISTENT COOL NORTHWEST
FLOW ALOFT...WITH SERIES OF SHEARED MID-LEVEL SHORT WAVE FEATURES
ROTATING THROUGH THE WESTERN PERIPHERY OF THE UPPER LOW. THIS
PRESENTS A DAILY THREAT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON/EVENING DIURNALLY FAVORED
INSTABILITY MAXIMA...WITH COVERAGE LIKELY LIMITED SOMEWHAT AND
TIED TO LOCALIZED BOUNDARY LAYER CONVERGENCE LINES. CURRENT
AFTERNOON GOES WATER VAPOR IMAGERY DEPICTS A WEAK MID-LEVEL SHORT
WAVE FEATURE DROPPING SOUTHWARD ACROSS WESTERN ONTARIO WHICH SHOULD
ARRIVE OVER THE AREA TUESDAY MORNING...AND MODELS INDICATE ANOTHER
SUCH FEATURE PASSING THROUGH WEDNESDAY. STRONGER HEIGHT FALLS OCCUR
FRIDAY INTO AS UPPER TROUGH RETROGRADES. GIVEN THESE CONTINUED
GUIDANCE TRENDS HAVE MAINTAINED GENERALLY LOW CHANCE POPS MAINLY FOR
AFTERNOON/EARLY EVENING PERIODS TUESDAY-THURSDAY...WITH SLIGHTLY
HIGHER POPS FRIDAY-SATURDAY WITH TROUGH OVERHEAD. TROUGH AXIS DRIFTS
OFF TO THE EAST SATURDAY NIGHT INTO SUNDAY INDICATING A RESPITE FROM
PRECIP THREAT BEFORE ANOTHER SHORT WAVE DIGS IN FROM THE NORTHWEST
ON MONDAY.

HIGH TEMPS HAVE STRUGGLED TO TOP 70 ACROSS NORTHEASTERN PARTS OF THE
FORECAST AREA TODAY...AND EVEN TO REACH THE MID 60S ALONG THE
INDIANA LAKE SHORE WITH STRONG GUSTY NORTH WINDS. DIMINISHING WINDS
AND A VERY GRADUAL MODERATION IN TEMPS ALOFT WILL HELP NUDGE TEMPS
INTO THE MID AND UPPER 70S OVER THE NEXT FEW DAYS. MORE OF A
NORTHWEST COMPONENT TO WIND TUESDAY SHOULD KEEP LAKE COOLING MAINLY
IN NORTHWEST INDIANA...AND WEAKER LAKE BREEZES OVER THE NEXT FEW
DAYS SHOULD ALLOW SHORE AREAS TO PEAK IN THE 70-75 DEGREE RANGE
MID-LATE WEEK. TEMPS NEAR 80 BY SUNDAY/MONDAY WILL AT LEAST BE ONLY
A FEW DEGREES FROM EARLY AUGUST NORMALS.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* GUSTY N-NNE WINDS EASING LATE AFTERNOON THEN DIMINISHING EARLY EVENING.

* LOW CHANCE FOR SOME SCATTERED THUNDERSTORMS TUESDAY AFTERNOON.

MDB

//DISCUSSION...UPDATED 20Z...

LAKE BOUNDARY IS NOW WELL WEST OF MDW AND RIGHT NEAR THE WEST END
OF ORD AT 1935Z. THE BOUNDARY CONTINUES TO WOBBLE BACK AND FORTH
AT ORD WHICH IS LIKELY ACCOUNTING FOR THE ERRATIC WIND SPEEDS.
DIRECTIONAL CHANGE IS MINIMAL AND RANGES FROM ABOUT 360 TO 030
DEGREES. WIND TRENDS LATE THIS AFTERNOON WILL BE A
CHALLENGE...ESPECIALLY DETERMINING WHEN SPEEDS WILL BEGIN TO
DIMINISH. HAVE MADE SOME ADJUSTMENTS TO TRY AND DETAIL THE CHANGES
WITH THE 20Z TAF UPDATE. IF THE BOUNDARY REMAINS IN CLOSE
PROXIMITY TO ORD THEN SPEEDS COULD DROP OFF MORE QUICKLY AS THE
BOUNDARY DISSIPATES AND MIXING WINDS DOWN INTO THE EVENING. IF IT
STAYS WEST THEN SPEEDS WOULD STAY UP A BIT LONGER.

FROM 18Z...

STRONG PRESSURE GRADIENT CONTINUES ACROSS THE TERMINALS WITH GUSTS
IN THE 20-25 KT RANGE ACROSS IL AND PUSHING 30 KT AT TIMES NEAR
THE LAKE MICHIGAN SHORE OF NW INDIANA. THE DIRECTION CONTINUES TO
FLUCTUATE BETWEEN N AND NNE AND WILL LIKELY CONTINUE TO DO SO
THROUGH AFTERNOON. THE PRESSURE GRADIENT SLACKENS LATE THIS
AFTERNOON SO SPEEDS SHOULD EASE BUT THIS MAY TAKE SOME TIME INTO
THE EVENING. WIND DIRECTION MAY BECOME VARIABLE THIS EVENING WITH
A LIGHT NORTHWEST DIRECTION EXPECTED OVERNIGHT. A STEADIER
NORTHWEST WIND IS EXPECTED TUESDAY. A LAKE BREEZE MAY TURN WINDS
NORTHEAST AT GYY TUESDAY AFTERNOON BUT WILL KEEP THE LAKE BREEZE
EAST OF ORD/MDW FOR NOW.

A SERIES OF UPPER WAVES WILL CROSS THE AREA THE NEXT FEW DAYS WITH
ONE WAVE PASSING OVERNIGHT POTENTIALLY BRINGING SOME MID CLOUDS.
WEAK ASCENT WILL BE IN PLACE TUESDAY WHICH MAY TRIGGER SOME ISOLD-
SCT SHRA/TSRA DURING THE AFTERNOON. THREAT IS TOO LOW TO MENTION
IN THE TAF AT THIS TIME. OTHERWISE SHOULD SEE AN INCREASE IN
DIURNAL CLOUDS.

MDB

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* HIGH CONFIDENCE IN WIND TRENDS THROUGH MID AFTERNOON. MEDIUM
  CONFIDENCE IN NNE WINDS BECOMING NE LATE THIS AFTERNOON WITH
  SPEEDS EASING INTO EARLY EVENING.

* HIGH CONFIDENCE THAT TSRA CHANCES ARE LOW TUESDAY AFTERNOON AND
  COVERAGE WOULD BE ISOLATED TO SCATTERED.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
124 PM CDT

NORTHERLY WINDS CONTINUE UP AROUND 25 KT ACROSS THE SOUTHERN HALF OF
THE LAKE EARLY THIS AFTERNOON...AND THIS IS CONTINUING TO RESULT IN
BUOY OBSERVATIONS OF 8 TO 10 FOOT WAVES. THESE WINDS WILL GRADUALLY
EASE LATE THIS AFTERNOON AND EVENING...AND EVEN BECOME WESTERLY
TONIGHT AS THE GRADIENT WEAKENS. HOWEVER...WAVE HEIGHTS WILL BE SLOW
TO SUBSIDE...WITH 4+ FOOTERS EXPECTED ACROSS SOUTHERN LAKE MICHIGAN
THROUGH MUCH OF TONIGHT. NO CHANGES ARE PLANNED TO THE CURRENT
ENDING TIMES OF THE SMALL CRAFT ADVISORIES.

FOLLOWING TODAY`S WIND AND WAVE EVENT...IT APPEARS THE WEATHER WILL
BE SOMEWHAT QUIET ACROSS THE LAKE DURING THE WEEK. AN UPPER LEVEL
LOW OVER QUEBEC WILL CONTINUE TO LEAD TO A WEST NORTHWESTERLY FLOW
PATTERN...ALBEIT LIGHT...ACROSS THE LAKE THROUGH MUCH OF THE PERIOD
AS A COUPLE OF WEAK COLD FRONTAL BOUNDARIES DROP SOUTHWARD OVER THE
LAKE.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 281944
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
244 PM CDT MON JUL 28 2014

.DISCUSSION...
244 PM CDT

MAIN FOCUS THROUGH THE FORECAST PERIOD REMAINS ON COOLER THAN NORMAL
WEATHER FOR LATE JULY AND EARLY AUGUST...AND LOW CHANCE POPS FOR
DAILY DIURNAL SHOWER/THUNDERSTORM POTENTIAL.

MORNING UPPER AIR ANALYSIS DEPICTS ANOMALOUSLY DEEP EASTERN NORTH
AMERICAN UPPER TROUGH WITH AN UPPER LOW OVER CENTRAL QUEBEC. THIS
FEATURE IS PROGGED TO SLOWLY RETROGRADE WESTWARD TOWARD JAMES BAY
THROUGH FRIDAY BEFORE EVENTUALLY OPENING UP AND LIFTING OUT TO THE
NORTHEAST OVER THE WEEKEND. THIS PERSISTENT UPPER AIR PATTERN WILL
KEEP THE WESTERN GREAT LAKES REGION IN PERSISTENT COOL NORTHWEST
FLOW ALOFT...WITH SERIES OF SHEARED MID-LEVEL SHORT WAVE FEATURES
ROTATING THROUGH THE WESTERN PERIPHERY OF THE UPPER LOW. THIS
PRESENTS A DAILY THREAT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON/EVENING DIURNALLY FAVORED
INSTABILITY MAXIMA...WITH COVERAGE LIKELY LIMITED SOMEWHAT AND
TIED TO LOCALIZED BOUNDARY LAYER CONVERGENCE LINES. CURRENT
AFTERNOON GOES WATER VAPOR IMAGERY DEPICTS A WEAK MID-LEVEL SHORT
WAVE FEATURE DROPPING SOUTHWARD ACROSS WESTERN ONTARIO WHICH SHOULD
ARRIVE OVER THE AREA TUESDAY MORNING...AND MODELS INDICATE ANOTHER
SUCH FEATURE PASSING THROUGH WEDNESDAY. STRONGER HEIGHT FALLS OCCUR
FRIDAY INTO AS UPPER TROUGH RETROGRADES. GIVEN THESE CONTINUED
GUIDANCE TRENDS HAVE MAINTAINED GENERALLY LOW CHANCE POPS MAINLY FOR
AFTERNOON/EARLY EVENING PERIODS TUESDAY-THURSDAY...WITH SLIGHTLY
HIGHER POPS FRIDAY-SATURDAY WITH TROUGH OVERHEAD. TROUGH AXIS DRIFTS
OFF TO THE EAST SATURDAY NIGHT INTO SUNDAY INDICATING A RESPITE FROM
PRECIP THREAT BEFORE ANOTHER SHORT WAVE DIGS IN FROM THE NORTHWEST
ON MONDAY.

HIGH TEMPS HAVE STRUGGLED TO TOP 70 ACROSS NORTHEASTERN PARTS OF THE
FORECAST AREA TODAY...AND EVEN TO REACH THE MID 60S ALONG THE
INDIANA LAKE SHORE WITH STRONG GUSTY NORTH WINDS. DIMINISHING WINDS
AND A VERY GRADUAL MODERATION IN TEMPS ALOFT WILL HELP NUDGE TEMPS
INTO THE MID AND UPPER 70S OVER THE NEXT FEW DAYS. MORE OF A
NORTHWEST COMPONENT TO WIND TUESDAY SHOULD KEEP LAKE COOLING MAINLY
IN NORTHWEST INDIANA...AND WEAKER LAKE BREEZES OVER THE NEXT FEW
DAYS SHOULD ALLOW SHORE AREAS TO PEAK IN THE 70-75 DEGREE RANGE
MID-LATE WEEK. TEMPS NEAR 80 BY SUNDAY/MONDAY WILL AT LEAST BE ONLY
A FEW DEGREES FROM EARLY AUGUST NORMALS.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* GUSTY N-NNE WINDS EASING LATE AFTERNOON THEN DIMINISHING EARLY EVENING.

* LOW CHANCE FOR SOME SCATTERED THUNDERSTORMS TUESDAY AFTERNOON.

MDB

//DISCUSSION...UPDATED 20Z...

LAKE BOUNDARY IS NOW WELL WEST OF MDW AND RIGHT NEAR THE WEST END
OF ORD AT 1935Z. THE BOUNDARY CONTINUES TO WOBBLE BACK AND FORTH
AT ORD WHICH IS LIKELY ACCOUNTING FOR THE ERRATIC WIND SPEEDS.
DIRECTIONAL CHANGE IS MINIMAL AND RANGES FROM ABOUT 360 TO 030
DEGREES. WIND TRENDS LATE THIS AFTERNOON WILL BE A
CHALLENGE...ESPECIALLY DETERMINING WHEN SPEEDS WILL BEGIN TO
DIMINISH. HAVE MADE SOME ADJUSTMENTS TO TRY AND DETAIL THE CHANGES
WITH THE 20Z TAF UPDATE. IF THE BOUNDARY REMAINS IN CLOSE
PROXIMITY TO ORD THEN SPEEDS COULD DROP OFF MORE QUICKLY AS THE
BOUNDARY DISSIPATES AND MIXING WINDS DOWN INTO THE EVENING. IF IT
STAYS WEST THEN SPEEDS WOULD STAY UP A BIT LONGER.

FROM 18Z...

STRONG PRESSURE GRADIENT CONTINUES ACROSS THE TERMINALS WITH GUSTS
IN THE 20-25 KT RANGE ACROSS IL AND PUSHING 30 KT AT TIMES NEAR
THE LAKE MICHIGAN SHORE OF NW INDIANA. THE DIRECTION CONTINUES TO
FLUCTUATE BETWEEN N AND NNE AND WILL LIKELY CONTINUE TO DO SO
THROUGH AFTERNOON. THE PRESSURE GRADIENT SLACKENS LATE THIS
AFTERNOON SO SPEEDS SHOULD EASE BUT THIS MAY TAKE SOME TIME INTO
THE EVENING. WIND DIRECTION MAY BECOME VARIABLE THIS EVENING WITH
A LIGHT NORTHWEST DIRECTION EXPECTED OVERNIGHT. A STEADIER
NORTHWEST WIND IS EXPECTED TUESDAY. A LAKE BREEZE MAY TURN WINDS
NORTHEAST AT GYY TUESDAY AFTERNOON BUT WILL KEEP THE LAKE BREEZE
EAST OF ORD/MDW FOR NOW.

A SERIES OF UPPER WAVES WILL CROSS THE AREA THE NEXT FEW DAYS WITH
ONE WAVE PASSING OVERNIGHT POTENTIALLY BRINGING SOME MID CLOUDS.
WEAK ASCENT WILL BE IN PLACE TUESDAY WHICH MAY TRIGGER SOME ISOLD-
SCT SHRA/TSRA DURING THE AFTERNOON. THREAT IS TOO LOW TO MENTION
IN THE TAF AT THIS TIME. OTHERWISE SHOULD SEE AN INCREASE IN
DIURNAL CLOUDS.

MDB

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* HIGH CONFIDENCE IN WIND TRENDS THROUGH MID AFTERNOON. MEDIUM
  CONFIDENCE IN NNE WINDS BECOMING NE LATE THIS AFTERNOON WITH
  SPEEDS EASING INTO EARLY EVENING.

* HIGH CONFIDENCE THAT TSRA CHANCES ARE LOW TUESDAY AFTERNOON AND
  COVERAGE WOULD BE ISOLATED TO SCATTERED.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
124 PM CDT

NORTHERLY WINDS CONTINUE UP AROUND 25 KT ACROSS THE SOUTHERN HALF OF
THE LAKE EARLY THIS AFTERNOON...AND THIS IS CONTINUING TO RESULT IN
BUOY OBSERVATIONS OF 8 TO 10 FOOT WAVES. THESE WINDS WILL GRADUALLY
EASE LATE THIS AFTERNOON AND EVENING...AND EVEN BECOME WESTERLY
TONIGHT AS THE GRADIENT WEAKENS. HOWEVER...WAVE HEIGHTS WILL BE SLOW
TO SUBSIDE...WITH 4+ FOOTERS EXPECTED ACROSS SOUTHERN LAKE MICHIGAN
THROUGH MUCH OF TONIGHT. NO CHANGES ARE PLANNED TO THE CURRENT
ENDING TIMES OF THE SMALL CRAFT ADVISORIES.

FOLLOWING TODAY`S WIND AND WAVE EVENT...IT APPEARS THE WEATHER WILL
BE SOMEWHAT QUIET ACROSS THE LAKE DURING THE WEEK. AN UPPER LEVEL
LOW OVER QUEBEC WILL CONTINUE TO LEAD TO A WEST NORTHWESTERLY FLOW
PATTERN...ALBEIT LIGHT...ACROSS THE LAKE THROUGH MUCH OF THE PERIOD
AS A COUPLE OF WEAK COLD FRONTAL BOUNDARIES DROP SOUTHWARD OVER THE
LAKE.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 281943
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
243 PM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* GUSTY N-NNE WINDS EASING LATE AFTERNOON THEN DIMINISHING EARLY EVENING.

* LOW CHANCE FOR SOME SCATTERED THUNDERSTORMS TUESDAY AFTERNOON.

MDB

//DISCUSSION...UPDATED 20Z...

LAKE BOUNDARY IS NOW WELL WEST OF MDW AND RIGHT NEAR THE WEST END
OF ORD AT 1935Z. THE BOUNDARY CONTINUES TO WOBBLE BACK AND FORTH
AT ORD WHICH IS LIKELY ACCOUNTING FOR THE ERRATIC WIND SPEEDS.
DIRECTIONAL CHANGE IS MINIMAL AND RANGES FROM ABOUT 360 TO 030
DEGREES. WIND TRENDS LATE THIS AFTERNOON WILL BE A
CHALLENGE...ESPECIALLY DETERMINING WHEN SPEEDS WILL BEGIN TO
DIMINISH. HAVE MADE SOME ADJUSTMENTS TO TRY AND DETAIL THE CHANGES
WITH THE 20Z TAF UPDATE. IF THE BOUNDARY REMAINS IN CLOSE
PROXIMITY TO ORD THEN SPEEDS COULD DROP OFF MORE QUICKLY AS THE
BOUNDARY DISSIPATES AND MIXING WINDS DOWN INTO THE EVENING. IF IT
STAYS WEST THEN SPEEDS WOULD STAY UP A BIT LONGER.

FROM 18Z...

STRONG PRESSURE GRADIENT CONTINUES ACROSS THE TERMINALS WITH GUSTS
IN THE 20-25 KT RANGE ACROSS IL AND PUSHING 30 KT AT TIMES NEAR
THE LAKE MICHIGAN SHORE OF NW INDIANA. THE DIRECTION CONTINUES TO
FLUCTUATE BETWEEN N AND NNE AND WILL LIKELY CONTINUE TO DO SO
THROUGH AFTERNOON. THE PRESSURE GRADIENT SLACKENS LATE THIS
AFTERNOON SO SPEEDS SHOULD EASE BUT THIS MAY TAKE SOME TIME INTO
THE EVENING. WIND DIRECTION MAY BECOME VARIABLE THIS EVENING WITH
A LIGHT NORTHWEST DIRECTION EXPECTED OVERNIGHT. A STEADIER
NORTHWEST WIND IS EXPECTED TUESDAY. A LAKE BREEZE MAY TURN WINDS
NORTHEAST AT GYY TUESDAY AFTERNOON BUT WILL KEEP THE LAKE BREEZE
EAST OF ORD/MDW FOR NOW.

A SERIES OF UPPER WAVES WILL CROSS THE AREA THE NEXT FEW DAYS WITH
ONE WAVE PASSING OVERNIGHT POTENTIALLY BRINGING SOME MID CLOUDS.
WEAK ASCENT WILL BE IN PLACE TUESDAY WHICH MAY TRIGGER SOME ISOLD-
SCT SHRA/TSRA DURING THE AFTERNOON. THREAT IS TOO LOW TO MENTION
IN THE TAF AT THIS TIME. OTHERWISE SHOULD SEE AN INCREASE IN
DIURNAL CLOUDS.

MDB

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* HIGH CONFIDENCE IN WIND TRENDS THROUGH MID AFTERNOON. MEDIUM
  CONFIDENCE IN NNE WINDS BECOMING NE LATE THIS AFTERNOON WITH
  SPEEDS EASING INTO EARLY EVENING.

* HIGH CONFIDENCE THAT TSRA CHANCES ARE LOW TUESDAY AFTERNOON AND
  COVERAGE WOULD BE ISOLATED TO SCATTERED.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
124 PM CDT

NORTHERLY WINDS CONTINUE UP AROUND 25 KT ACROSS THE SOUTHERN HALF OF
THE LAKE EARLY THIS AFTERNOON...AND THIS IS CONTINUING TO RESULT IN
BUOY OBSERVATIONS OF 8 TO 10 FOOT WAVES. THESE WINDS WILL GRADUALLY
EASE LATE THIS AFTERNOON AND EVENING...AND EVEN BECOME WESTERLY
TONIGHT AS THE GRADIENT WEAKENS. HOWEVER...WAVE HEIGHTS WILL BE SLOW
TO SUBSIDE...WITH 4+ FOOTERS EXPECTED ACROSS SOUTHERN LAKE MICHIGAN
THROUGH MUCH OF TONIGHT. NO CHANGES ARE PLANNED TO THE CURRENT
ENDING TIMES OF THE SMALL CRAFT ADVISORIES.

FOLLOWING TODAY`S WIND AND WAVE EVENT...IT APPEARS THE WEATHER WILL
BE SOMEWHAT QUIET ACROSS THE LAKE DURING THE WEEK. AN UPPER LEVEL
LOW OVER QUEBEC WILL CONTINUE TO LEAD TO A WEST NORTHWESTERLY FLOW
PATTERN...ALBEIT LIGHT...ACROSS THE LAKE THROUGH MUCH OF THE PERIOD
AS A COUPLE OF WEAK COLD FRONTAL BOUNDARIES DROP SOUTHWARD OVER THE
LAKE.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 281943
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
243 PM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* GUSTY N-NNE WINDS EASING LATE AFTERNOON THEN DIMINISHING EARLY EVENING.

* LOW CHANCE FOR SOME SCATTERED THUNDERSTORMS TUESDAY AFTERNOON.

MDB

//DISCUSSION...UPDATED 20Z...

LAKE BOUNDARY IS NOW WELL WEST OF MDW AND RIGHT NEAR THE WEST END
OF ORD AT 1935Z. THE BOUNDARY CONTINUES TO WOBBLE BACK AND FORTH
AT ORD WHICH IS LIKELY ACCOUNTING FOR THE ERRATIC WIND SPEEDS.
DIRECTIONAL CHANGE IS MINIMAL AND RANGES FROM ABOUT 360 TO 030
DEGREES. WIND TRENDS LATE THIS AFTERNOON WILL BE A
CHALLENGE...ESPECIALLY DETERMINING WHEN SPEEDS WILL BEGIN TO
DIMINISH. HAVE MADE SOME ADJUSTMENTS TO TRY AND DETAIL THE CHANGES
WITH THE 20Z TAF UPDATE. IF THE BOUNDARY REMAINS IN CLOSE
PROXIMITY TO ORD THEN SPEEDS COULD DROP OFF MORE QUICKLY AS THE
BOUNDARY DISSIPATES AND MIXING WINDS DOWN INTO THE EVENING. IF IT
STAYS WEST THEN SPEEDS WOULD STAY UP A BIT LONGER.

FROM 18Z...

STRONG PRESSURE GRADIENT CONTINUES ACROSS THE TERMINALS WITH GUSTS
IN THE 20-25 KT RANGE ACROSS IL AND PUSHING 30 KT AT TIMES NEAR
THE LAKE MICHIGAN SHORE OF NW INDIANA. THE DIRECTION CONTINUES TO
FLUCTUATE BETWEEN N AND NNE AND WILL LIKELY CONTINUE TO DO SO
THROUGH AFTERNOON. THE PRESSURE GRADIENT SLACKENS LATE THIS
AFTERNOON SO SPEEDS SHOULD EASE BUT THIS MAY TAKE SOME TIME INTO
THE EVENING. WIND DIRECTION MAY BECOME VARIABLE THIS EVENING WITH
A LIGHT NORTHWEST DIRECTION EXPECTED OVERNIGHT. A STEADIER
NORTHWEST WIND IS EXPECTED TUESDAY. A LAKE BREEZE MAY TURN WINDS
NORTHEAST AT GYY TUESDAY AFTERNOON BUT WILL KEEP THE LAKE BREEZE
EAST OF ORD/MDW FOR NOW.

A SERIES OF UPPER WAVES WILL CROSS THE AREA THE NEXT FEW DAYS WITH
ONE WAVE PASSING OVERNIGHT POTENTIALLY BRINGING SOME MID CLOUDS.
WEAK ASCENT WILL BE IN PLACE TUESDAY WHICH MAY TRIGGER SOME ISOLD-
SCT SHRA/TSRA DURING THE AFTERNOON. THREAT IS TOO LOW TO MENTION
IN THE TAF AT THIS TIME. OTHERWISE SHOULD SEE AN INCREASE IN
DIURNAL CLOUDS.

MDB

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* HIGH CONFIDENCE IN WIND TRENDS THROUGH MID AFTERNOON. MEDIUM
  CONFIDENCE IN NNE WINDS BECOMING NE LATE THIS AFTERNOON WITH
  SPEEDS EASING INTO EARLY EVENING.

* HIGH CONFIDENCE THAT TSRA CHANCES ARE LOW TUESDAY AFTERNOON AND
  COVERAGE WOULD BE ISOLATED TO SCATTERED.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
124 PM CDT

NORTHERLY WINDS CONTINUE UP AROUND 25 KT ACROSS THE SOUTHERN HALF OF
THE LAKE EARLY THIS AFTERNOON...AND THIS IS CONTINUING TO RESULT IN
BUOY OBSERVATIONS OF 8 TO 10 FOOT WAVES. THESE WINDS WILL GRADUALLY
EASE LATE THIS AFTERNOON AND EVENING...AND EVEN BECOME WESTERLY
TONIGHT AS THE GRADIENT WEAKENS. HOWEVER...WAVE HEIGHTS WILL BE SLOW
TO SUBSIDE...WITH 4+ FOOTERS EXPECTED ACROSS SOUTHERN LAKE MICHIGAN
THROUGH MUCH OF TONIGHT. NO CHANGES ARE PLANNED TO THE CURRENT
ENDING TIMES OF THE SMALL CRAFT ADVISORIES.

FOLLOWING TODAY`S WIND AND WAVE EVENT...IT APPEARS THE WEATHER WILL
BE SOMEWHAT QUIET ACROSS THE LAKE DURING THE WEEK. AN UPPER LEVEL
LOW OVER QUEBEC WILL CONTINUE TO LEAD TO A WEST NORTHWESTERLY FLOW
PATTERN...ALBEIT LIGHT...ACROSS THE LAKE THROUGH MUCH OF THE PERIOD
AS A COUPLE OF WEAK COLD FRONTAL BOUNDARIES DROP SOUTHWARD OVER THE
LAKE.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 281826
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
126 PM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* GUSTY N-NNE WINDS EASING LATE AFTERNOON THEN DIMINISHING EARLY EVENING.

* LOW CHANCE FOR SOME SCATTERED THUNDERSTORMS TUESDAY AFTERNOON.

MDB

//DISCUSSION...UPDATED 18Z...

STRONG PRESSURE GRADIENT CONTINUES ACROSS THE TERMINALS WITH GUSTS
IN THE 20-25 KT RANGE ACROSS IL AND PUSHING 30 KT AT TIMES NEAR
THE LAKE MICHIGAN SHORE OF NW INDIANA. THE DIRECTION CONTINUES TO
FLUCTUATE BETWEEN N AND NNE AND WILL LIKELY CONTINUE TO DO SO
THROUGH AFTERNOON. THE PRESSURE GRADIENT SLACKENS LATE THIS
AFTERNOON SO SPEEDS SHOULD EASE BUT THIS MAY TAKE SOME TIME INTO
THE EVENING. WIND DIRECTION MAY BECOME VARIABLE THIS EVENING WITH
A LIGHT NORTHWEST DIRECTION EXPECTED OVERNIGHT. A STEADIER
NORTHWEST WIND IS EXPECTED TUESDAY. A LAKE BREEZE MAY TURN WINDS
NORTHEAST AT GYY TUESDAY AFTERNOON BUT WILL KEEP THE LAKE BREEZE
EAST OF ORD/MDW FOR NOW.

A SERIES OF UPPER WAVES WILL CROSS THE AREA THE NEXT FEW DAYS WITH
ONE WAVE PASSING OVERNIGHT POTENTIALLY BRINGING SOME MID CLOUDS.
WEAK ASCENT WILL BE IN PLACE TUESDAY WHICH MAY TRIGGER SOME ISOLD-
SCT SHRA/TSRA DURING THE AFTERNOON. THREAT IS TOO LOW TO MENTION
IN THE TAF AT THIS TIME. OTHERWISE SHOULD SEE AN INCREASE IN
DIURNAL CLOUDS.

MDB

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* HIGH CONFIDENCE IN WIND TRENDS THROUGH MID AFTERNOON. MEDIUM
  CONFIDENCE IN NNE WINDS LATE THIS AFTERNOON WITH SPEEDS EASING.
  WINDS MAY BECOME VARIABLE UNDER 10 KT THIS EVENING.

* HIGH CONFIDENCE THAT TSRA CHANCES ARE LOW TUESDAY AFTERNOON AND
  COVERAGE WOULD BE ISOLATED TO SCATTERED.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
124 PM CDT

NORTHERLY WINDS CONTINUE UP AROUND 25 KT ACROSS THE SOUTHERN HALF OF
THE LAKE EARLY THIS AFTERNOON...AND THIS IS CONTINUING TO RESULT IN
BUOY OBSERVATIONS OF 8 TO 10 FOOT WAVES. THESE WINDS WILL GRADUALLY
EASE LATE THIS AFTERNOON AND EVENING...AND EVEN BECOME WESTERLY
TONIGHT AS THE GRADIENT WEAKENS. HOWEVER...WAVE HEIGHTS WILL BE SLOW
TO SUBSIDE...WITH 4+ FOOTERS EXPECTED ACROSS SOUTHERN LAKE MICHIGAN
THROUGH MUCH OF TONIGHT. NO CHANGES ARE PLANNED TO THE CURRENT
ENDDING TIMES OF THE SMALL CRAFT ADVISORIES.

FOLLOWING TODAY`S WIND AND WAVE EVENT...IT APPEARS THE WEATHER WILL
BE SOMEWHAT QUIET ACROSS THE LAKE DURING THE WEEK. AN UPPER LEVEL
LOW OVER QUEBEC WILL CONTINUE TO LEAD TO A WEST NORTHWESTERLY FLOW
PATTERN...ALBEIT LIGHT...ACROSS THE LAKE THROUGH MUCH OF THE PERIOD
AS A COUPLE OF WEAK COLD FRONTAL BOUNDARIES DROP SOUTHWARD OVER THE
LAKE.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 281826
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
126 PM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* GUSTY N-NNE WINDS EASING LATE AFTERNOON THEN DIMINISHING EARLY EVENING.

* LOW CHANCE FOR SOME SCATTERED THUNDERSTORMS TUESDAY AFTERNOON.

MDB

//DISCUSSION...UPDATED 18Z...

STRONG PRESSURE GRADIENT CONTINUES ACROSS THE TERMINALS WITH GUSTS
IN THE 20-25 KT RANGE ACROSS IL AND PUSHING 30 KT AT TIMES NEAR
THE LAKE MICHIGAN SHORE OF NW INDIANA. THE DIRECTION CONTINUES TO
FLUCTUATE BETWEEN N AND NNE AND WILL LIKELY CONTINUE TO DO SO
THROUGH AFTERNOON. THE PRESSURE GRADIENT SLACKENS LATE THIS
AFTERNOON SO SPEEDS SHOULD EASE BUT THIS MAY TAKE SOME TIME INTO
THE EVENING. WIND DIRECTION MAY BECOME VARIABLE THIS EVENING WITH
A LIGHT NORTHWEST DIRECTION EXPECTED OVERNIGHT. A STEADIER
NORTHWEST WIND IS EXPECTED TUESDAY. A LAKE BREEZE MAY TURN WINDS
NORTHEAST AT GYY TUESDAY AFTERNOON BUT WILL KEEP THE LAKE BREEZE
EAST OF ORD/MDW FOR NOW.

A SERIES OF UPPER WAVES WILL CROSS THE AREA THE NEXT FEW DAYS WITH
ONE WAVE PASSING OVERNIGHT POTENTIALLY BRINGING SOME MID CLOUDS.
WEAK ASCENT WILL BE IN PLACE TUESDAY WHICH MAY TRIGGER SOME ISOLD-
SCT SHRA/TSRA DURING THE AFTERNOON. THREAT IS TOO LOW TO MENTION
IN THE TAF AT THIS TIME. OTHERWISE SHOULD SEE AN INCREASE IN
DIURNAL CLOUDS.

MDB

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* HIGH CONFIDENCE IN WIND TRENDS THROUGH MID AFTERNOON. MEDIUM
  CONFIDENCE IN NNE WINDS LATE THIS AFTERNOON WITH SPEEDS EASING.
  WINDS MAY BECOME VARIABLE UNDER 10 KT THIS EVENING.

* HIGH CONFIDENCE THAT TSRA CHANCES ARE LOW TUESDAY AFTERNOON AND
  COVERAGE WOULD BE ISOLATED TO SCATTERED.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
124 PM CDT

NORTHERLY WINDS CONTINUE UP AROUND 25 KT ACROSS THE SOUTHERN HALF OF
THE LAKE EARLY THIS AFTERNOON...AND THIS IS CONTINUING TO RESULT IN
BUOY OBSERVATIONS OF 8 TO 10 FOOT WAVES. THESE WINDS WILL GRADUALLY
EASE LATE THIS AFTERNOON AND EVENING...AND EVEN BECOME WESTERLY
TONIGHT AS THE GRADIENT WEAKENS. HOWEVER...WAVE HEIGHTS WILL BE SLOW
TO SUBSIDE...WITH 4+ FOOTERS EXPECTED ACROSS SOUTHERN LAKE MICHIGAN
THROUGH MUCH OF TONIGHT. NO CHANGES ARE PLANNED TO THE CURRENT
ENDDING TIMES OF THE SMALL CRAFT ADVISORIES.

FOLLOWING TODAY`S WIND AND WAVE EVENT...IT APPEARS THE WEATHER WILL
BE SOMEWHAT QUIET ACROSS THE LAKE DURING THE WEEK. AN UPPER LEVEL
LOW OVER QUEBEC WILL CONTINUE TO LEAD TO A WEST NORTHWESTERLY FLOW
PATTERN...ALBEIT LIGHT...ACROSS THE LAKE THROUGH MUCH OF THE PERIOD
AS A COUPLE OF WEAK COLD FRONTAL BOUNDARIES DROP SOUTHWARD OVER THE
LAKE.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 281759
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1259 PM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* GUSTY N-NNE WINDS EASING LATE AFTERNOON THEN DIMINISHING EARLY EVENING.

* LOW CHANCE FOR SOME SCATTERED THUNDERSTORMS TUESDAY AFTERNOON.

MDB

//DISCUSSION...UPDATED 18Z...

STRONG PRESSURE GRADIENT CONTINUES ACROSS THE TERMINALS WITH GUSTS
IN THE 20-25 KT RANGE ACROSS IL AND PUSHING 30 KT AT TIMES NEAR
THE LAKE MICHIGAN SHORE OF NW INDIANA. THE DIRECTION CONTINUES TO
FLUCTUATE BETWEEN N AND NNE AND WILL LIKELY CONTINUE TO DO SO
THROUGH AFTERNOON. THE PRESSURE GRADIENT SLACKENS LATE THIS
AFTERNOON SO SPEEDS SHOULD EASE BUT THIS MAY TAKE SOME TIME INTO
THE EVENING. WIND DIRECTION MAY BECOME VARIABLE THIS EVENING WITH
A LIGHT NORTHWEST DIRECTION EXPECTED OVERNIGHT. A STEADIER
NORTHWEST WIND IS EXPECTED TUESDAY. A LAKE BREEZE MAY TURN WINDS
NORTHEAST AT GYY TUESDAY AFTERNOON BUT WILL KEEP THE LAKE BREEZE
EAST OF ORD/MDW FOR NOW.

A SERIES OF UPPER WAVES WILL CROSS THE AREA THE NEXT FEW DAYS WITH
ONE WAVE PASSING OVERNIGHT POTENTIALLY BRINGING SOME MID CLOUDS.
WEAK ASCENT WILL BE IN PLACE TUESDAY WHICH MAY TRIGGER SOME ISOLD-
SCT SHRA/TSRA DURING THE AFTERNOON. THREAT IS TOO LOW TO MENTION
IN THE TAF AT THIS TIME. OTHERWISE SHOULD SEE AN INCREASE IN
DIURNAL CLOUDS.

MDB


//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* HIGH CONFIDENCE IN WIND TRENDS THROUGH MID AFTERNOON. MEDIUM
  CONFIDENCE IN NNE WINDS LATE THIS AFTERNOON WITH SPEEDS EASING.
  WINDS MAY BECOME VARIABLE UNDER 10 KT THIS EVENING.

* HIGH CONFIDENCE THAT TSRA CHANCES ARE LOW TUESDAY AFTERNOON AND
  COVERAGE WOULD BE ISOLATED TO SCATTERED.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 281608
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1108 AM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.

MDB

//DISCUSSION...UPDATED 16Z...

WINDS CONTINUE TO FLUCTUATE BETWEEN N AND NNW AT ORD/MDW BUT AM
STILL ANTICIPATING A STEADIER NNE DIRECTION TO TAKE OVER INTO
MIDDAY. LATEST RADAR IMAGERY DOES SHOW A BOUNDARY MOVING INLAND
FROM THE LAKE AND THIS MAY BRING THE SHIFT TO NNE OVER THE NEXT
HOUR. STILL NOT HIGHLY CONFIDENT IN DIRECTION VERY LATE THIS
AFTERNOON INTO THE EARLY EVENING BUT SPEEDS WILL BEGIN TO DIMINISH
DURING THAT TIME. WILL CONTINUE WITH THE NNE DIRECTION FOR NOW.

MDB

FROM 12Z...

LOW PRESSURE WILL CONTINUE TO DEPART EASTWARD FROM THE EASTERN
GREAT LAKES REGION. THE PRESSURE GRADIENT IN ITS WAKE WILL LINGER
THROUGH EARLY AFTERNOON SUPPORTING WIND GUSTS OF 18-22KT. THE WIND
DIRECTION AT ORD AND MDW ARE LIKELY TO TURN FROM NORTH-NORTHWEST
TO MORE NORTH-NORTHEAST SOMETIME THIS MID TO LATE MORNING DUE TO
LOCAL EFFECTS OF THE LAKE. THERE IS UNCERTAINTY ON THE WIND
DIRECTION LATE THIS AFTERNOON INTO EARLY EVE AS IT COULD TURN MORE
NORTHEAST WITH ALMOST AN INFLUENCE OF A LAKE BREEZE ENHANCEMENT TO
THE SYNOPTIC WIND. IF THAT DOES NOT OCCUR...THE WIND DIRECTION
COULD BACK MORE TO THE NORTH-NORTHWEST.

SCATTERED CUMULUS ARE EXPECTED THIS AFTERNOON WITH POSSIBLY SOME
SCATTERED VFR CLOUDS TONIGHT INTO EARLY TUESDAY MORNING.

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* HIGH IN WIND SPEED AND MEDIUM IN NNE WIND DIRECTION THROUGH MID-
  AFTERNOON. LOW IN NNE WIND DIRECTION FROM 22Z-02Z.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 281608
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1108 AM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.

MDB

//DISCUSSION...UPDATED 16Z...

WINDS CONTINUE TO FLUCTUATE BETWEEN N AND NNW AT ORD/MDW BUT AM
STILL ANTICIPATING A STEADIER NNE DIRECTION TO TAKE OVER INTO
MIDDAY. LATEST RADAR IMAGERY DOES SHOW A BOUNDARY MOVING INLAND
FROM THE LAKE AND THIS MAY BRING THE SHIFT TO NNE OVER THE NEXT
HOUR. STILL NOT HIGHLY CONFIDENT IN DIRECTION VERY LATE THIS
AFTERNOON INTO THE EARLY EVENING BUT SPEEDS WILL BEGIN TO DIMINISH
DURING THAT TIME. WILL CONTINUE WITH THE NNE DIRECTION FOR NOW.

MDB

FROM 12Z...

LOW PRESSURE WILL CONTINUE TO DEPART EASTWARD FROM THE EASTERN
GREAT LAKES REGION. THE PRESSURE GRADIENT IN ITS WAKE WILL LINGER
THROUGH EARLY AFTERNOON SUPPORTING WIND GUSTS OF 18-22KT. THE WIND
DIRECTION AT ORD AND MDW ARE LIKELY TO TURN FROM NORTH-NORTHWEST
TO MORE NORTH-NORTHEAST SOMETIME THIS MID TO LATE MORNING DUE TO
LOCAL EFFECTS OF THE LAKE. THERE IS UNCERTAINTY ON THE WIND
DIRECTION LATE THIS AFTERNOON INTO EARLY EVE AS IT COULD TURN MORE
NORTHEAST WITH ALMOST AN INFLUENCE OF A LAKE BREEZE ENHANCEMENT TO
THE SYNOPTIC WIND. IF THAT DOES NOT OCCUR...THE WIND DIRECTION
COULD BACK MORE TO THE NORTH-NORTHWEST.

SCATTERED CUMULUS ARE EXPECTED THIS AFTERNOON WITH POSSIBLY SOME
SCATTERED VFR CLOUDS TONIGHT INTO EARLY TUESDAY MORNING.

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* HIGH IN WIND SPEED AND MEDIUM IN NNE WIND DIRECTION THROUGH MID-
  AFTERNOON. LOW IN NNE WIND DIRECTION FROM 22Z-02Z.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 281341
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
841 AM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 14Z...

* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.

MDB

//DISCUSSION...UPDATED 12Z...

LOW PRESSURE WILL CONTINUE TO DEPART EASTWARD FROM THE EASTERN
GREAT LAKES REGION. THE PRESSURE GRADIENT IN ITS WAKE WILL LINGER
THROUGH EARLY AFTERNOON SUPPORTING WIND GUSTS OF 18-22KT. THE WIND
DIRECTION AT ORD AND MDW ARE LIKELY TO TURN FROM NORTH-NORTHWEST
TO MORE NORTH-NORTHEAST SOMETIME THIS MID TO LATE MORNING DUE TO
LOCAL EFFECTS OF THE LAKE. THERE IS UNCERTAINTY ON THE WIND
DIRECTION LATE THIS AFTERNOON INTO EARLY EVE AS IT COULD TURN MORE
NORTHEAST WITH ALMOST AN INFLUENCE OF A LAKE BREEZE ENHANCEMENT TO
THE SYNOPTIC WIND. IF THAT DOES NOT OCCUR...THE WIND DIRECTION
COULD BACK MORE TO THE NORTH-NORTHWEST.

SCATTERED CUMULUS ARE EXPECTED THIS AFTERNOON WITH POSSIBLY SOME
SCATTERED VFR CLOUDS TONIGHT INTO EARLY TUESDAY MORNING.

//ORD AND MDW CONFIDENCE...UPDATED 14Z...

* HIGH IN WIND SPEED AND MEDIUM IN NNE WIND DIRECTION THROUGH MID-
  AFTERNOON. LOW IN NNE WIND DIRECTION FROM 22Z-02Z.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 281341
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
841 AM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 14Z...

* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.

MDB

//DISCUSSION...UPDATED 12Z...

LOW PRESSURE WILL CONTINUE TO DEPART EASTWARD FROM THE EASTERN
GREAT LAKES REGION. THE PRESSURE GRADIENT IN ITS WAKE WILL LINGER
THROUGH EARLY AFTERNOON SUPPORTING WIND GUSTS OF 18-22KT. THE WIND
DIRECTION AT ORD AND MDW ARE LIKELY TO TURN FROM NORTH-NORTHWEST
TO MORE NORTH-NORTHEAST SOMETIME THIS MID TO LATE MORNING DUE TO
LOCAL EFFECTS OF THE LAKE. THERE IS UNCERTAINTY ON THE WIND
DIRECTION LATE THIS AFTERNOON INTO EARLY EVE AS IT COULD TURN MORE
NORTHEAST WITH ALMOST AN INFLUENCE OF A LAKE BREEZE ENHANCEMENT TO
THE SYNOPTIC WIND. IF THAT DOES NOT OCCUR...THE WIND DIRECTION
COULD BACK MORE TO THE NORTH-NORTHWEST.

SCATTERED CUMULUS ARE EXPECTED THIS AFTERNOON WITH POSSIBLY SOME
SCATTERED VFR CLOUDS TONIGHT INTO EARLY TUESDAY MORNING.

//ORD AND MDW CONFIDENCE...UPDATED 14Z...

* HIGH IN WIND SPEED AND MEDIUM IN NNE WIND DIRECTION THROUGH MID-
  AFTERNOON. LOW IN NNE WIND DIRECTION FROM 22Z-02Z.

MDB

//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 281133
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
633 AM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 12Z...

* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.


//DISCUSSION...UPDATED 12Z...

LOW PRESSURE WILL CONTINUE TO DEPART EASTWARD FROM THE EASTERN
GREAT LAKES REGION. THE PRESSURE GRADIENT IN ITS WAKE WILL LINGER
THROUGH EARLY AFTERNOON SUPPORTING WIND GUSTS OF 18-22KT. THE WIND
DIRECTION AT ORD AND MDW ARE LIKELY TO TURN FROM NORTH-NORTHWEST
TO MORE NORTH-NORTHEAST SOMETIME THIS MID TO LATE MORNING DUE TO
LOCAL EFFECTS OF THE LAKE. THERE IS UNCERTAINTY ON THE WIND
DIRECTION LATE THIS AFTERNOON INTO EARLY EVE AS IT COULD TURN MORE
NORTHEAST WITH ALMOST AN INFLUENCE OF A LAKE BREEZE ENHANCEMENT TO
THE SYNOPTIC WIND. IF THAT DOES NOT OCCUR...THE WIND DIRECTION
COULD BACK MORE TO THE NORTH-NORTHWEST.

SCATTERED CUMULUS ARE EXPECTED THIS AFTERNOON WITH POSSIBLY SOME
SCATTERED VFR CLOUDS TONIGHT INTO EARLY TUESDAY MORNING.


//ORD AND MDW CONFIDENCE...UPDATED 12Z...

* HIGH IN WIND SPEED AND MEDIUM IN NNE WIND DIRECTION THROUGH MID-
  AFTERNOON. LOW IN NNE WIND DIRECTION FROM 22Z-02Z.


//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS
     UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN
     UNTIL 4 AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 281133
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
633 AM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 12Z...

* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.


//DISCUSSION...UPDATED 12Z...

LOW PRESSURE WILL CONTINUE TO DEPART EASTWARD FROM THE EASTERN
GREAT LAKES REGION. THE PRESSURE GRADIENT IN ITS WAKE WILL LINGER
THROUGH EARLY AFTERNOON SUPPORTING WIND GUSTS OF 18-22KT. THE WIND
DIRECTION AT ORD AND MDW ARE LIKELY TO TURN FROM NORTH-NORTHWEST
TO MORE NORTH-NORTHEAST SOMETIME THIS MID TO LATE MORNING DUE TO
LOCAL EFFECTS OF THE LAKE. THERE IS UNCERTAINTY ON THE WIND
DIRECTION LATE THIS AFTERNOON INTO EARLY EVE AS IT COULD TURN MORE
NORTHEAST WITH ALMOST AN INFLUENCE OF A LAKE BREEZE ENHANCEMENT TO
THE SYNOPTIC WIND. IF THAT DOES NOT OCCUR...THE WIND DIRECTION
COULD BACK MORE TO THE NORTH-NORTHWEST.

SCATTERED CUMULUS ARE EXPECTED THIS AFTERNOON WITH POSSIBLY SOME
SCATTERED VFR CLOUDS TONIGHT INTO EARLY TUESDAY MORNING.


//ORD AND MDW CONFIDENCE...UPDATED 12Z...

* HIGH IN WIND SPEED AND MEDIUM IN NNE WIND DIRECTION THROUGH MID-
  AFTERNOON. LOW IN NNE WIND DIRECTION FROM 22Z-02Z.


//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...

TUESDAY NIGHT...SLIGHT CHANCE OF AN EVE STORM.
WEDNESDAY-SATURDAY...MAINLY VFR. SLIGHT CHANCE OF AFTERNOON TSRA.
SUNDAY...VFR.

MTF

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS
     UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN
     UNTIL 4 AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 280832
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
332 AM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 09Z...

* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.


//DISCUSSION...UPDATED 06Z...

LOW PRESSURE WILL CONTINUE TO MOVE AWAY ACROSS THE NORTHEAST U.S.
WITH NORTHERLY WINDS CONTINUING OVER THE TAF SITES THROUGH TODAY.
ON THE LOCAL SCALE AT ORD AND MDW...THE WIND DIRECTION IS LIKELY
TO WOBBLE SOME BETWEEN 340 AND 020 THROUGH EARLY MORNING AND THEN
BECOME MORE 010-020 FROM MID-MORNING ON DUE TO INFLUENCE OF THE
NEARBY LAKE. WIND GUSTS AT TIMES TODAY OF 20 KT OR SLIGHTLY HIGHER
ARE LIKELY. SCATTERED CUMULUS ARE LIKELY TODAY BUT NO
PRECIPITATION EXPECTED.


//ORD AND MDW CONFIDENCE...UPDATED 09Z...

* HIGH IN WIND SPEED AND MEDIUM IN WIND DIRECTION...INCLUDING 15Z
  TIMING OF NORTH-NORTHEAST DIRECTION.


//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

MTF/IZZI

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 280832
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
332 AM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 09Z...

* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.


//DISCUSSION...UPDATED 06Z...

LOW PRESSURE WILL CONTINUE TO MOVE AWAY ACROSS THE NORTHEAST U.S.
WITH NORTHERLY WINDS CONTINUING OVER THE TAF SITES THROUGH TODAY.
ON THE LOCAL SCALE AT ORD AND MDW...THE WIND DIRECTION IS LIKELY
TO WOBBLE SOME BETWEEN 340 AND 020 THROUGH EARLY MORNING AND THEN
BECOME MORE 010-020 FROM MID-MORNING ON DUE TO INFLUENCE OF THE
NEARBY LAKE. WIND GUSTS AT TIMES TODAY OF 20 KT OR SLIGHTLY HIGHER
ARE LIKELY. SCATTERED CUMULUS ARE LIKELY TODAY BUT NO
PRECIPITATION EXPECTED.


//ORD AND MDW CONFIDENCE...UPDATED 09Z...

* HIGH IN WIND SPEED AND MEDIUM IN WIND DIRECTION...INCLUDING 15Z
  TIMING OF NORTH-NORTHEAST DIRECTION.


//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

MTF/IZZI

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 280752
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
252 AM CDT MON JUL 28 2014

.DISCUSSION...
251 AM CDT

SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL
TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD.
WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY
ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A
LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST.  THE SURFACE
LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS.

WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE
LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO
STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY
HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING
CONDITIONS AT ALL OF THE BEACHES.  RIP CURRENTS ARE EXPECTED.

WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS
DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS
OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL
INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN.

TUESDAY THROUGH THURSDAY...
THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH
SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT.  THE MAIN THEME FOR
THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING
AROUND THE UPPER LEVEL LOW.  THESE STREAMERS MAY PROVIDE ENOUGH
FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM
DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE
LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK
FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE
SHOULD BE PLENTY OF DRY HOURS.

LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE
IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO
AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND
60...AND IN THE LOW 60S DOWNTOWN.

FRIDAY THROUGH SUNDAY...
A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH
WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS.  AT THIS POINT
INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES
NOT LOOK FAVORABLE FOR SEVERE WEATHER.  HAVE ANOTHER LESS IMPRESSIVE
CHANCE OF AFTERNOON STORMS SATURDAY.  TEMPERATURES REMAIN BELOW
NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* TEMPORARY MVFR CIGS POSSIBLE PRIOR TO DAYBREAK.
* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.

//DISCUSSION...UPDATED 06Z...

LOW PRESSURE WILL CONTINUE TO MOVE AWAY ACROSS THE NORTHEAST U.S.
WITH NORTHERLY WINDS CONTINUING OVER THE TAF SITES THROUGH TODAY.
ON THE LOCAL SCALE AT ORD AND MDW...THE WIND DIRECTION IS LIKELY
TO WOBBLE SOME BETWEEN 340 AND 020 THROUGH EARLY MORNING AND THEN
BECOME MORE 010-020 FROM MID-MORNING ON DUE TO INFLUENCE OF THE
NEARBY LAKE. WIND GUSTS AT TIMES TODAY OF 20 KT OR SLIGHTLY HIGHER
ARE LIKELY. SCATTERED CUMULUS ARE LIKELY TODAY BUT NO
PRECIPITATION EXPECTED.

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH THAT ANY MVFR CIGS WILL BE TEMPORARY AND ABOVE 2000 FT.
* HIGH IN WIND SPEED AND MEDIUM IN WIND DIRECTION...INCLUDING 15Z
  TIMING OF NORTH-NORTHEAST DIRECTION.

//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

MTF/IZZI

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 280717
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
217 AM CDT MON JUL 28 2014

.DISCUSSION...
731 PM CDT

RADAR IMAGERY CONTINUES TO SHOW WIDELY SCATTERED SHOWERS DRIFTING
SOUTH/SOUTHEAST THROUGH THE REGION AND INTO PRIMARILY NORTHERN
ILLINOIS. THE BULK OF THIS ACTIVITY HAS WEAKENED AS IT MOVED INTO
THE CWA WITH LITTLE TO NO THUNDER. AS STOUT VORT LOBE SHIFTS
EAST/SOUTHEAST THIS EVENING...CURRENT SURFACE TROUGH TO THE NORTH
WILL WEAKEN AS IT MOVES SOUTH WITH CURRENT COVERAGE OF SHOWER
ACTIVITY LESSENING OVER THE NEXT COUPLE OF HOURS BEFORE DRY
CONDITIONS EXPECTED OVERNIGHT. IN THE NEAR TERM...DID KEEP LOW
CHANCE POPS FOR SCATTERED SHOWERS PRIMARILY OVER NORTHEAST
ILLINOIS AND NORTHWEST INDIANA FOR THE NEXT COUPLE OF
HOURS...REMOVING ANY MENTION OF THUNDER.

RODRIGUEZ

//PREV DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* TEMPORARY MVFR CIGS POSSIBLE PRIOR TO DAYBREAK.
* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.

//DISCUSSION...UPDATED 06Z...

LOW PRESSURE WILL CONTINUE TO MOVE AWAY ACROSS THE NORTHEAST U.S.
WITH NORTHERLY WINDS CONTINUING OVER THE TAF SITES THROUGH TODAY.
ON THE LOCAL SCALE AT ORD AND MDW...THE WIND DIRECTION IS LIKELY
TO WOBBLE SOME BETWEEN 340 AND 020 THROUGH EARLY MORNING AND THEN
BECOME MORE 010-020 FROM MID-MORNING ON DUE TO INFLUENCE OF THE
NEARBY LAKE. WIND GUSTS AT TIMES TODAY OF 20 KT OR SLIGHTLY HIGHER
ARE LIKELY. SCATTERED CUMULUS ARE LIKELY TODAY BUT NO
PRECIPITATION EXPECTED.

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH THAT ANY MVFR CIGS WILL BE TEMPORARY AND ABOVE 2000 FT.
* HIGH IN WIND SPEED AND MEDIUM IN WIND DIRECTION...INCLUDING 15Z
  TIMING OF NORTH-NORTHEAST DIRECTION.

//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

MTF/IZZI

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 280717
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
217 AM CDT MON JUL 28 2014

.DISCUSSION...
731 PM CDT

RADAR IMAGERY CONTINUES TO SHOW WIDELY SCATTERED SHOWERS DRIFTING
SOUTH/SOUTHEAST THROUGH THE REGION AND INTO PRIMARILY NORTHERN
ILLINOIS. THE BULK OF THIS ACTIVITY HAS WEAKENED AS IT MOVED INTO
THE CWA WITH LITTLE TO NO THUNDER. AS STOUT VORT LOBE SHIFTS
EAST/SOUTHEAST THIS EVENING...CURRENT SURFACE TROUGH TO THE NORTH
WILL WEAKEN AS IT MOVES SOUTH WITH CURRENT COVERAGE OF SHOWER
ACTIVITY LESSENING OVER THE NEXT COUPLE OF HOURS BEFORE DRY
CONDITIONS EXPECTED OVERNIGHT. IN THE NEAR TERM...DID KEEP LOW
CHANCE POPS FOR SCATTERED SHOWERS PRIMARILY OVER NORTHEAST
ILLINOIS AND NORTHWEST INDIANA FOR THE NEXT COUPLE OF
HOURS...REMOVING ANY MENTION OF THUNDER.

RODRIGUEZ

//PREV DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* TEMPORARY MVFR CIGS POSSIBLE PRIOR TO DAYBREAK.
* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.

//DISCUSSION...UPDATED 06Z...

LOW PRESSURE WILL CONTINUE TO MOVE AWAY ACROSS THE NORTHEAST U.S.
WITH NORTHERLY WINDS CONTINUING OVER THE TAF SITES THROUGH TODAY.
ON THE LOCAL SCALE AT ORD AND MDW...THE WIND DIRECTION IS LIKELY
TO WOBBLE SOME BETWEEN 340 AND 020 THROUGH EARLY MORNING AND THEN
BECOME MORE 010-020 FROM MID-MORNING ON DUE TO INFLUENCE OF THE
NEARBY LAKE. WIND GUSTS AT TIMES TODAY OF 20 KT OR SLIGHTLY HIGHER
ARE LIKELY. SCATTERED CUMULUS ARE LIKELY TODAY BUT NO
PRECIPITATION EXPECTED.

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH THAT ANY MVFR CIGS WILL BE TEMPORARY AND ABOVE 2000 FT.
* HIGH IN WIND SPEED AND MEDIUM IN WIND DIRECTION...INCLUDING 15Z
  TIMING OF NORTH-NORTHEAST DIRECTION.

//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

MTF/IZZI

&&

.MARINE...
215 AM CDT

IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS
MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM
OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY
AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL
EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT
BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE
NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT.
WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE
EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK
TUESDAY.

A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH
MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS
WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON
TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL
HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL
REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH
SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE
ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL
SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 280542
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1242 AM CDT MON JUL 28 2014

.DISCUSSION...
731 PM CDT

RADAR IMAGERY CONTINUES TO SHOW WIDELY SCATTERED SHOWERS DRIFTING
SOUTH/SOUTHEAST THROUGH THE REGION AND INTO PRIMARILY NORTHERN
ILLINOIS. THE BULK OF THIS ACTIVITY HAS WEAKENED AS IT MOVED INTO
THE CWA WITH LITTLE TO NO THUNDER. AS STOUT VORT LOBE SHIFTS
EAST/SOUTHEAST THIS EVENING...CURRENT SURFACE TROUGH TO THE NORTH
WILL WEAKEN AS IT MOVES SOUTH WITH CURRENT COVERAGE OF SHOWER
ACTIVITY LESSENING OVER THE NEXT COUPLE OF HOURS BEFORE DRY
CONDITIONS EXPECTED OVERNIGHT. IN THE NEAR TERM...DID KEEP LOW
CHANCE POPS FOR SCATTERED SHOWERS PRIMARILY OVER NORTHEAST
ILLINOIS AND NORTHWEST INDIANA FOR THE NEXT COUPLE OF
HOURS...REMOVING ANY MENTION OF THUNDER.

RODRIGUEZ

//PREV DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* TEMPORARY MVFR CIGS POSSIBLE PRIOR TO DAYBREAK.
* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.


//DISCUSSION...UPDATED 06Z...

LOW PRESSURE WILL CONTINUE TO MOVE AWAY ACROSS THE NORTHEAST U.S.
WITH NORTHERLY WINDS CONTINUING OVER THE TAF SITES THROUGH TODAY.
ON THE LOCAL SCALE AT ORD AND MDW...THE WIND DIRECTION IS LIKELY
TO WOBBLE SOME BETWEEN 340 AND 020 THROUGH EARLY MORNING AND THEN
BECOME MORE 010-020 FROM MID-MORNING ON DUE TO INFLUENCE OF THE
NEARBY LAKE. WIND GUSTS AT TIMES TODAY OF 20 KT OR SLIGHTLY HIGHER
ARE LIKELY. SCATTERED CUMULUS ARE LIKELY TODAY BUT NO
PRECIPITATION EXPECTED.


//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH THAT ANY MVFR CIGS WILL BE TEMPORARY AND ABOVE 2000 FT.
* HIGH IN WIND SPEED AND MEDIUM IN WIND DIRECTION...INCLUDING 15Z
  TIMING OF NORTH-NORTHEAST DIRECTION.


//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

MTF/IZZI

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 280542
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1242 AM CDT MON JUL 28 2014

.DISCUSSION...
731 PM CDT

RADAR IMAGERY CONTINUES TO SHOW WIDELY SCATTERED SHOWERS DRIFTING
SOUTH/SOUTHEAST THROUGH THE REGION AND INTO PRIMARILY NORTHERN
ILLINOIS. THE BULK OF THIS ACTIVITY HAS WEAKENED AS IT MOVED INTO
THE CWA WITH LITTLE TO NO THUNDER. AS STOUT VORT LOBE SHIFTS
EAST/SOUTHEAST THIS EVENING...CURRENT SURFACE TROUGH TO THE NORTH
WILL WEAKEN AS IT MOVES SOUTH WITH CURRENT COVERAGE OF SHOWER
ACTIVITY LESSENING OVER THE NEXT COUPLE OF HOURS BEFORE DRY
CONDITIONS EXPECTED OVERNIGHT. IN THE NEAR TERM...DID KEEP LOW
CHANCE POPS FOR SCATTERED SHOWERS PRIMARILY OVER NORTHEAST
ILLINOIS AND NORTHWEST INDIANA FOR THE NEXT COUPLE OF
HOURS...REMOVING ANY MENTION OF THUNDER.

RODRIGUEZ

//PREV DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* TEMPORARY MVFR CIGS POSSIBLE PRIOR TO DAYBREAK.
* GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY.


//DISCUSSION...UPDATED 06Z...

LOW PRESSURE WILL CONTINUE TO MOVE AWAY ACROSS THE NORTHEAST U.S.
WITH NORTHERLY WINDS CONTINUING OVER THE TAF SITES THROUGH TODAY.
ON THE LOCAL SCALE AT ORD AND MDW...THE WIND DIRECTION IS LIKELY
TO WOBBLE SOME BETWEEN 340 AND 020 THROUGH EARLY MORNING AND THEN
BECOME MORE 010-020 FROM MID-MORNING ON DUE TO INFLUENCE OF THE
NEARBY LAKE. WIND GUSTS AT TIMES TODAY OF 20 KT OR SLIGHTLY HIGHER
ARE LIKELY. SCATTERED CUMULUS ARE LIKELY TODAY BUT NO
PRECIPITATION EXPECTED.


//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH THAT ANY MVFR CIGS WILL BE TEMPORARY AND ABOVE 2000 FT.
* HIGH IN WIND SPEED AND MEDIUM IN WIND DIRECTION...INCLUDING 15Z
  TIMING OF NORTH-NORTHEAST DIRECTION.


//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

MTF/IZZI

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 280308
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1008 PM CDT SUN JUL 27 2014

.DISCUSSION...
731 PM CDT

RADAR IMAGERY CONTINUES TO SHOW WIDELY SCATTERED SHOWERS DRIFTING
SOUTH/SOUTHEAST THROUGH THE REGION AND INTO PRIMARILY NORTHERN
ILLINOIS. THE BULK OF THIS ACTIVITY HAS WEAKENED AS IT MOVED INTO
THE CWA WITH LITTLE TO NO THUNDER. AS STOUT VORT LOBE SHIFTS
EAST/SOUTHEAST THIS EVENING...CURRENT SURFACE TROUGH TO THE NORTH
WILL WEAKEN AS IT MOVES SOUTH WITH CURRENT COVERAGE OF SHOWER
ACTIVITY LESSENING OVER THE NEXT COUPLE OF HOURS BEFORE DRY
CONDITIONS EXPECTED OVERNIGHT. IN THE NEAR TERM...DID KEEP LOW
CHANCE POPS FOR SCATTERED SHOWERS PRIMARILY OVER NORTHEAST
ILLINOIS AND NORTHWEST INDIANA FOR THE NEXT COUPLE OF
HOURS...REMOVING ANY MENTION OF THUNDER.

RODRIGUEZ

//PREV DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 03Z...

* STRONG WNW WINDS EASE EARLY THIS EVENING...THEN BECOME MORE
  NORTHERLY TOWARD MIDNIGHT
* GUSTY NORTH TO NORTHEAST WINDS LIKELY MONDAY
* CHANCE OF MVFR CIGS OVERNIGHT/MONDAY MORNING

IZZI

//DISCUSSION...UPDATED 03Z...

LAKE ENHANCED OUTFLOW BOUNDARY HAS PUSHED THROUGH ORD AND WILL
PUSH THROUGH MDW VERY SHORTLY. WINDS SHOULD TURN NNE OR NE AND
GUSTY FOR TIME BEHIND THE BOUNDARY BEFORE SETTLING BACK TO A MORE
NORTHERLY DIRECTION OVERNIGHT. SOME LAKE EFFECT MVFR CIGS MAY ALSO
BRIEFLY IMPACT THE ORD/MDW LATE THIS EVENING.

IZZI

UPDATED 00Z...

STRONG/GUSTY NORTHWEST WINDS WILL SUBSIDE WITH SUNSET. SECONDARY
TROUGH/COLD FRONT DROPPING SOUTH SHOULD RESULT IN WINDS SHIFTING
NORTH LATE THIS EVENING WITH DIRECTION LIKELY VARYING SOME BETWEEN
340-010. POCKETS OF MVFR CIGS OVER NORTHERN WISCONSIN AND NORTHERN
LAKE MICHIGAN BEHIND THIS TROUGH COULD TRANSLATE SOUTHWARD
BRINGING THE THREAT OF AT LEAST TEMPORARY MVFR CIGS OVERNIGHT INTO
MONDAY MORNING...BUT CONFIDENCE IS NOT OVERLY HIGH SO WILL MONITOR
TRENDS EARLY THIS EVENING. GRADIENT LOOKS TO SUPPORT NORTHERLY
WINDS 350-020 DURING THE DAY MONDAY...THOUGH THERE COULD BE SOME
LAKE INFLUENCE IN THE AFTERNOON RESULTING IN WINDS FAVORING MORE A
SLIGHTLY MORE EASTERLY COMPONENT.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 03Z...

* MEDIUM CONFIDENCE IN WIND TRENDS THROUGH THE TAF PERIOD
* LOW-MEDIUM CONFIDENCE IN CIGS FORECAST OVERNIGHT INTO EARLY
  MONDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

IZZI

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 280308
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1008 PM CDT SUN JUL 27 2014

.DISCUSSION...
731 PM CDT

RADAR IMAGERY CONTINUES TO SHOW WIDELY SCATTERED SHOWERS DRIFTING
SOUTH/SOUTHEAST THROUGH THE REGION AND INTO PRIMARILY NORTHERN
ILLINOIS. THE BULK OF THIS ACTIVITY HAS WEAKENED AS IT MOVED INTO
THE CWA WITH LITTLE TO NO THUNDER. AS STOUT VORT LOBE SHIFTS
EAST/SOUTHEAST THIS EVENING...CURRENT SURFACE TROUGH TO THE NORTH
WILL WEAKEN AS IT MOVES SOUTH WITH CURRENT COVERAGE OF SHOWER
ACTIVITY LESSENING OVER THE NEXT COUPLE OF HOURS BEFORE DRY
CONDITIONS EXPECTED OVERNIGHT. IN THE NEAR TERM...DID KEEP LOW
CHANCE POPS FOR SCATTERED SHOWERS PRIMARILY OVER NORTHEAST
ILLINOIS AND NORTHWEST INDIANA FOR THE NEXT COUPLE OF
HOURS...REMOVING ANY MENTION OF THUNDER.

RODRIGUEZ

//PREV DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 03Z...

* STRONG WNW WINDS EASE EARLY THIS EVENING...THEN BECOME MORE
  NORTHERLY TOWARD MIDNIGHT
* GUSTY NORTH TO NORTHEAST WINDS LIKELY MONDAY
* CHANCE OF MVFR CIGS OVERNIGHT/MONDAY MORNING

IZZI

//DISCUSSION...UPDATED 03Z...

LAKE ENHANCED OUTFLOW BOUNDARY HAS PUSHED THROUGH ORD AND WILL
PUSH THROUGH MDW VERY SHORTLY. WINDS SHOULD TURN NNE OR NE AND
GUSTY FOR TIME BEHIND THE BOUNDARY BEFORE SETTLING BACK TO A MORE
NORTHERLY DIRECTION OVERNIGHT. SOME LAKE EFFECT MVFR CIGS MAY ALSO
BRIEFLY IMPACT THE ORD/MDW LATE THIS EVENING.

IZZI

UPDATED 00Z...

STRONG/GUSTY NORTHWEST WINDS WILL SUBSIDE WITH SUNSET. SECONDARY
TROUGH/COLD FRONT DROPPING SOUTH SHOULD RESULT IN WINDS SHIFTING
NORTH LATE THIS EVENING WITH DIRECTION LIKELY VARYING SOME BETWEEN
340-010. POCKETS OF MVFR CIGS OVER NORTHERN WISCONSIN AND NORTHERN
LAKE MICHIGAN BEHIND THIS TROUGH COULD TRANSLATE SOUTHWARD
BRINGING THE THREAT OF AT LEAST TEMPORARY MVFR CIGS OVERNIGHT INTO
MONDAY MORNING...BUT CONFIDENCE IS NOT OVERLY HIGH SO WILL MONITOR
TRENDS EARLY THIS EVENING. GRADIENT LOOKS TO SUPPORT NORTHERLY
WINDS 350-020 DURING THE DAY MONDAY...THOUGH THERE COULD BE SOME
LAKE INFLUENCE IN THE AFTERNOON RESULTING IN WINDS FAVORING MORE A
SLIGHTLY MORE EASTERLY COMPONENT.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 03Z...

* MEDIUM CONFIDENCE IN WIND TRENDS THROUGH THE TAF PERIOD
* LOW-MEDIUM CONFIDENCE IN CIGS FORECAST OVERNIGHT INTO EARLY
  MONDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

IZZI

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 280040
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
740 PM CDT SUN JUL 27 2014

.DISCUSSION...
731 PM CDT

RADAR IMAGERY CONTINUES TO SHOW WIDELY SCATTERED SHOWERS DRIFTING
SOUTH/SOUTHEAST THROUGH THE REGION AND INTO PRIMARILY NORTHERN
ILLINOIS. THE BULK OF THIS ACTIVITY HAS WEAKENED AS IT MOVED INTO
THE CWA WITH LITTLE TO NO THUNDER. AS STOUT VORT LOBE SHIFTS
EAST/SOUTHEAST THIS EVENING...CURRENT SURFACE TROUGH TO THE NORTH
WILL WEAKEN AS IT MOVES SOUTH WITH CURRENT COVERAGE OF SHOWER
ACTIVITY LESSENING OVER THE NEXT COUPLE OF HOURS BEFORE DRY
CONDITIONS EXPECTED OVERNIGHT. IN THE NEAR TERM...DID KEEP LOW
CHANCE POPS FOR SCATTERED SHOWERS PRIMARILY OVER NORTHEAST
ILLINOIS AND NORTHWEST INDIANA FOR THE NEXT COUPLE OF
HOURS...REMOVING ANY MENTION OF THUNDER.

RODRIGUEZ

&&

.PREV DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* STRONG WNW WINDS EASE EARLY THIS EVENING...THEN BECOME MORE
  NORTHERLY TOWARD MIDNIGHT
* GUSTY NORTH TO NORTHEAST WINDS LIKELY MONDAY
* CHANCE OF MVFR CIGS OVERNIGHT/MONDAY MORNING

IZZI

//DISCUSSION...UPDATED 00Z...

STRONG/GUSTY NORTHWEST WINDS WILL SUBSIDE WITH SUNSET. SECONDARY
TROUGH/COLD FRONT DROPPING SOUTH SHOULD RESULT IN WINDS SHIFTING
NORTH LATE THIS EVENING WITH DIRECTION LIKELY VARYING SOME BETWEEN
340-010. POCKETS OF MVFR CIGS OVER NORTHERN WISCONSIN AND NORTHERN
LAKE MICHIGAN BEHIND THIS TROUGH COULD TRANSLATE SOUTHWARD
BRINGING THE THREAT OF AT LEAST TEMPORARY MVFR CIGS OVERNIGHT INTO
MONDAY MORNING...BUT CONFIDENCE IS NOT OVERLY HIGH SO WILL MONITOR
TRENDS EARLY THIS EVENING. GRADIENT LOOKS TO SUPPORT NORTHERLY
WINDS 350-020 DURING THE DAY MONDAY...THOUGH THERE COULD BE SOME
LAKE INFLUENCE IN THE AFTERNOON RESULTING IN WINDS FAVORING MORE A
SLIGHTLY MORE EASTERLY COMPONENT.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM CONFIDENCE IN WIND TRENDS THROUGH THE TAF PERIOD
* LOW-MEDIUM CONFIDENCE IN CIGS FORECAST OVERNIGHT INTO EARLY
  MONDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

IZZI

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 280040
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
740 PM CDT SUN JUL 27 2014

.DISCUSSION...
731 PM CDT

RADAR IMAGERY CONTINUES TO SHOW WIDELY SCATTERED SHOWERS DRIFTING
SOUTH/SOUTHEAST THROUGH THE REGION AND INTO PRIMARILY NORTHERN
ILLINOIS. THE BULK OF THIS ACTIVITY HAS WEAKENED AS IT MOVED INTO
THE CWA WITH LITTLE TO NO THUNDER. AS STOUT VORT LOBE SHIFTS
EAST/SOUTHEAST THIS EVENING...CURRENT SURFACE TROUGH TO THE NORTH
WILL WEAKEN AS IT MOVES SOUTH WITH CURRENT COVERAGE OF SHOWER
ACTIVITY LESSENING OVER THE NEXT COUPLE OF HOURS BEFORE DRY
CONDITIONS EXPECTED OVERNIGHT. IN THE NEAR TERM...DID KEEP LOW
CHANCE POPS FOR SCATTERED SHOWERS PRIMARILY OVER NORTHEAST
ILLINOIS AND NORTHWEST INDIANA FOR THE NEXT COUPLE OF
HOURS...REMOVING ANY MENTION OF THUNDER.

RODRIGUEZ

&&

.PREV DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* STRONG WNW WINDS EASE EARLY THIS EVENING...THEN BECOME MORE
  NORTHERLY TOWARD MIDNIGHT
* GUSTY NORTH TO NORTHEAST WINDS LIKELY MONDAY
* CHANCE OF MVFR CIGS OVERNIGHT/MONDAY MORNING

IZZI

//DISCUSSION...UPDATED 00Z...

STRONG/GUSTY NORTHWEST WINDS WILL SUBSIDE WITH SUNSET. SECONDARY
TROUGH/COLD FRONT DROPPING SOUTH SHOULD RESULT IN WINDS SHIFTING
NORTH LATE THIS EVENING WITH DIRECTION LIKELY VARYING SOME BETWEEN
340-010. POCKETS OF MVFR CIGS OVER NORTHERN WISCONSIN AND NORTHERN
LAKE MICHIGAN BEHIND THIS TROUGH COULD TRANSLATE SOUTHWARD
BRINGING THE THREAT OF AT LEAST TEMPORARY MVFR CIGS OVERNIGHT INTO
MONDAY MORNING...BUT CONFIDENCE IS NOT OVERLY HIGH SO WILL MONITOR
TRENDS EARLY THIS EVENING. GRADIENT LOOKS TO SUPPORT NORTHERLY
WINDS 350-020 DURING THE DAY MONDAY...THOUGH THERE COULD BE SOME
LAKE INFLUENCE IN THE AFTERNOON RESULTING IN WINDS FAVORING MORE A
SLIGHTLY MORE EASTERLY COMPONENT.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM CONFIDENCE IN WIND TRENDS THROUGH THE TAF PERIOD
* LOW-MEDIUM CONFIDENCE IN CIGS FORECAST OVERNIGHT INTO EARLY
  MONDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

IZZI

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 272331
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
631 PM CDT SUN JUL 27 2014

.DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* STRONG WNW WINDS EASE EARLY THIS EVENING...THEN BECOME MORE
  NORTHERLY TOWARD MIDNIGHT
* GUSTY NORTH TO NORTHEAST WINDS LIKELY MONDAY
* CHANCE OF MVFR CIGS OVERNIGHT/MONDAY MORNING

IZZI

//DISCUSSION...UPDATED 00Z...

STRONG/GUSTY NORTHWEST WINDS WILL SUBSIDE WITH SUNSET. SECONDARY
TROUGH/COLD FRONT DROPPING SOUTH SHOULD RESULT IN WINDS SHIFTING
NORTH LATE THIS EVENING WITH DIRECTION LIKELY VARYING SOME BETWEEN
340-010. POCKETS OF MVFR CIGS OVER NORTHERN WISCONSIN AND NORTHERN
LAKE MICHIGAN BEHIND THIS TROUGH COULD TRANSLATE SOUTHWARD
BRINGING THE THREAT OF AT LEAST TEMPORARY MVFR CIGS OVERNIGHT INTO
MONDAY MORNING...BUT CONFIDENCE IS NOT OVERLY HIGH SO WILL MONITOR
TRENDS EARLY THIS EVENING. GRADIENT LOOKS TO SUPPORT NORTHERLY
WINDS 350-020 DURING THE DAY MONDAY...THOUGH THERE COULD BE SOME
LAKE INFLUENCE IN THE AFTERNOON RESULTING IN WINDS FAVORING MORE A
SLIGHTLY MORE EASTERLY COMPONENT.

IZZI


//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM CONFIDENCE IN WIND TRENDS THROUGH THE TAF PERIOD
* LOW-MEDIUM CONFIDENCE IN CIGS FORECAST OVERNIGHT INTO EARLY
  MONDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

IZZI

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO
     NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN
     CITY IN UNTIL 4 AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 272331
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
631 PM CDT SUN JUL 27 2014

.DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* STRONG WNW WINDS EASE EARLY THIS EVENING...THEN BECOME MORE
  NORTHERLY TOWARD MIDNIGHT
* GUSTY NORTH TO NORTHEAST WINDS LIKELY MONDAY
* CHANCE OF MVFR CIGS OVERNIGHT/MONDAY MORNING

IZZI

//DISCUSSION...UPDATED 00Z...

STRONG/GUSTY NORTHWEST WINDS WILL SUBSIDE WITH SUNSET. SECONDARY
TROUGH/COLD FRONT DROPPING SOUTH SHOULD RESULT IN WINDS SHIFTING
NORTH LATE THIS EVENING WITH DIRECTION LIKELY VARYING SOME BETWEEN
340-010. POCKETS OF MVFR CIGS OVER NORTHERN WISCONSIN AND NORTHERN
LAKE MICHIGAN BEHIND THIS TROUGH COULD TRANSLATE SOUTHWARD
BRINGING THE THREAT OF AT LEAST TEMPORARY MVFR CIGS OVERNIGHT INTO
MONDAY MORNING...BUT CONFIDENCE IS NOT OVERLY HIGH SO WILL MONITOR
TRENDS EARLY THIS EVENING. GRADIENT LOOKS TO SUPPORT NORTHERLY
WINDS 350-020 DURING THE DAY MONDAY...THOUGH THERE COULD BE SOME
LAKE INFLUENCE IN THE AFTERNOON RESULTING IN WINDS FAVORING MORE A
SLIGHTLY MORE EASTERLY COMPONENT.

IZZI


//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM CONFIDENCE IN WIND TRENDS THROUGH THE TAF PERIOD
* LOW-MEDIUM CONFIDENCE IN CIGS FORECAST OVERNIGHT INTO EARLY
  MONDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR.

IZZI

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO
     NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN
     CITY IN UNTIL 4 AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 272203
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
503 PM CDT SUN JUL 27 2014

.DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 22Z...

* STRONG/GUSTY WEST/NORTHWEST WINDS THRU EARLY EVENING
* ISOLD OF SHRA THROUGH SUNSET
* WINDS BECOME MORE NORTHERLY THIS EVENING
* CHANCE OF MVFR CIGS LATE EVENING/OVERNIGHT
* GUSTY NORTH/NORTHEAST WINDS MONDAY

IZZI

//DISCUSSION...UPDATED 18Z...

FRONTAL BOUNDARY JUST EAST OF ORD/MDW WITH A FEW CELLS DEVELOPING
OVER THE LAKE AND ADDITIONAL DEVELOPMENT SHOULD REMAIN EAST OF
ORD/MDW BUT MAY STILL IMPACT GYY THROUGH 19Z OR SO UNTIL THE FRONT
PUSHES EAST OF THERE. AS COOLER AIR ALOFT SPREADS ACROSS THE AREA
THIS AFTERNOON...THERE COULD BE SOME INSTABILITY SHOWERS...
PERHAPS ISOLATED THUNDER...FROM MID AFTERNOON THROUGH EARLY
EVENING.

WEST/NORTHWEST WINDS HAVE INCREASED INTO THE 15-20KT RANGE WITH
GUSTS INTO THE MID 20KT RANGE. WITH COOLER AND DRIER AIR ADVECTING
INTO THE REGION...LOW LEVEL MIXING WILL BE FAIRLY EFFICIENT
BRINGING STRONGER WINDS TO THE SURFACE AND BUMPED SPEEDS/GUSTS UP
JUST A BIT WITH GUSTS INTO THE UPPER 20KT RANGE POSSIBLE FOR MUCH
OF THE AFTERNOON/EARLY EVENING.

ANOTHER COLD FRONT/WIND SHIFT IS EXPECTED THIS EVENING WHICH WILL
LIKELY SHIFT WINDS TO THE NORTH/NORTHEAST. CHANGES TO TIMING MAY
BE NEEDED WITH FUTURE UPDATES BUT CONFIDENCE FOR A SHIFT TO THE
NORTH/NORTHEAST IS INCREASING. IN ADDITION...THERE COULD BE A
PERIOD OF MVFR CIGS BEHIND THIS FRONT. WINDS WILL TEND TO SHIFT
BACK NORTH/NORTHWEST OVERNIGHT...THEN SHIFT BACK NORTH/NORTHEAST
MONDAY MORNING AND REMAIN GUSTY FOR MUCH OF MONDAY. CMS

//ORD AND MDW CONFIDENCE...UPDATED 22Z...

* HIGH FOR WINDS THIS AFTERNOON...MEDIUM FOR THE REST OF THE
  PERIOD
* HIGH CONFIDENCE IN LOW COVERAGE ISOLD FOR SHRA INTO EARLY
  EVENING
* LOW CONFIDENCE FOR MVFR CIGS LATE EVENING/OVERNIGHT

IZZI

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 272203
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
503 PM CDT SUN JUL 27 2014

.DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 22Z...

* STRONG/GUSTY WEST/NORTHWEST WINDS THRU EARLY EVENING
* ISOLD OF SHRA THROUGH SUNSET
* WINDS BECOME MORE NORTHERLY THIS EVENING
* CHANCE OF MVFR CIGS LATE EVENING/OVERNIGHT
* GUSTY NORTH/NORTHEAST WINDS MONDAY

IZZI

//DISCUSSION...UPDATED 18Z...

FRONTAL BOUNDARY JUST EAST OF ORD/MDW WITH A FEW CELLS DEVELOPING
OVER THE LAKE AND ADDITIONAL DEVELOPMENT SHOULD REMAIN EAST OF
ORD/MDW BUT MAY STILL IMPACT GYY THROUGH 19Z OR SO UNTIL THE FRONT
PUSHES EAST OF THERE. AS COOLER AIR ALOFT SPREADS ACROSS THE AREA
THIS AFTERNOON...THERE COULD BE SOME INSTABILITY SHOWERS...
PERHAPS ISOLATED THUNDER...FROM MID AFTERNOON THROUGH EARLY
EVENING.

WEST/NORTHWEST WINDS HAVE INCREASED INTO THE 15-20KT RANGE WITH
GUSTS INTO THE MID 20KT RANGE. WITH COOLER AND DRIER AIR ADVECTING
INTO THE REGION...LOW LEVEL MIXING WILL BE FAIRLY EFFICIENT
BRINGING STRONGER WINDS TO THE SURFACE AND BUMPED SPEEDS/GUSTS UP
JUST A BIT WITH GUSTS INTO THE UPPER 20KT RANGE POSSIBLE FOR MUCH
OF THE AFTERNOON/EARLY EVENING.

ANOTHER COLD FRONT/WIND SHIFT IS EXPECTED THIS EVENING WHICH WILL
LIKELY SHIFT WINDS TO THE NORTH/NORTHEAST. CHANGES TO TIMING MAY
BE NEEDED WITH FUTURE UPDATES BUT CONFIDENCE FOR A SHIFT TO THE
NORTH/NORTHEAST IS INCREASING. IN ADDITION...THERE COULD BE A
PERIOD OF MVFR CIGS BEHIND THIS FRONT. WINDS WILL TEND TO SHIFT
BACK NORTH/NORTHWEST OVERNIGHT...THEN SHIFT BACK NORTH/NORTHEAST
MONDAY MORNING AND REMAIN GUSTY FOR MUCH OF MONDAY. CMS

//ORD AND MDW CONFIDENCE...UPDATED 22Z...

* HIGH FOR WINDS THIS AFTERNOON...MEDIUM FOR THE REST OF THE
  PERIOD
* HIGH CONFIDENCE IN LOW COVERAGE ISOLD FOR SHRA INTO EARLY
  EVENING
* LOW CONFIDENCE FOR MVFR CIGS LATE EVENING/OVERNIGHT

IZZI

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 271956
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
256 PM CDT SUN JUL 27 2014

.DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* STRONG/GUSTY WEST/NORTHWEST WINDS THRU EARLY EVENING.
* CHANCE OF SHRA MID AFTERNOON THRU THIS EVENING.
* WIND SHIFT TO NORTH/NORTHEAST MID/LATE EVENING.
* CHANCE OF MVFR CIGS LATE EVENING/OVERNIGHT.
* GUSTY NORTH/NORTHEAST WINDS MONDAY. CMS

//DISCUSSION...UPDATED 18Z...

FRONTAL BOUNDARY JUST EAST OF ORD/MDW WITH A FEW CELLS DEVELOPING
OVER THE LAKE AND ADDITIONAL DEVELOPMENT SHOULD REMAIN EAST OF
ORD/MDW BUT MAY STILL IMPACT GYY THROUGH 19Z OR SO UNTIL THE FRONT
PUSHES EAST OF THERE. AS COOLER AIR ALOFT SPREADS ACROSS THE AREA
THIS AFTERNOON...THERE COULD BE SOME INSTABILITY SHOWERS...
PERHAPS ISOLATED THUNDER...FROM MID AFTERNOON THROUGH EARLY
EVENING.

WEST/NORTHWEST WINDS HAVE INCREASED INTO THE 15-20KT RANGE WITH
GUSTS INTO THE MID 20KT RANGE. WITH COOLER AND DRIER AIR ADVECTING
INTO THE REGION...LOW LEVEL MIXING WILL BE FAIRLY EFFICIENT
BRINGING STRONGER WINDS TO THE SURFACE AND BUMPED SPEEDS/GUSTS UP
JUST A BIT WITH GUSTS INTO THE UPPER 20KT RANGE POSSIBLE FOR MUCH
OF THE AFTERNOON/EARLY EVENING.

ANOTHER COLD FRONT/WIND SHIFT IS EXPECTED THIS EVENING WHICH WILL
LIKELY SHIFT WINDS TO THE NORTH/NORTHEAST. CHANGES TO TIMING MAY
BE NEEDED WITH FUTURE UPDATES BUT CONFIDENCE FOR A SHIFT TO THE
NORTH/NORTHEAST IS INCREASING. IN ADDITION...THERE COULD BE A
PERIOD OF MVFR CIGS BEHIND THIS FRONT. WINDS WILL TEND TO SHIFT
BACK NORTH/NORTHWEST OVERNIGHT...THEN SHIFT BACK NORTH/NORTHEAST
MONDAY MORNING AND REMAIN GUSTY FOR MUCH OF MONDAY. CMS

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* HIGH FOR WINDS THIS AFTERNOON...MEDIUM FOR THE REST OF THE PERIOD.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* MEDIUM FOR MVFR CIGS LATE EVENING/OVERNIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY
     IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL
     4 AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 271956
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
256 PM CDT SUN JUL 27 2014

.DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* STRONG/GUSTY WEST/NORTHWEST WINDS THRU EARLY EVENING.
* CHANCE OF SHRA MID AFTERNOON THRU THIS EVENING.
* WIND SHIFT TO NORTH/NORTHEAST MID/LATE EVENING.
* CHANCE OF MVFR CIGS LATE EVENING/OVERNIGHT.
* GUSTY NORTH/NORTHEAST WINDS MONDAY. CMS

//DISCUSSION...UPDATED 18Z...

FRONTAL BOUNDARY JUST EAST OF ORD/MDW WITH A FEW CELLS DEVELOPING
OVER THE LAKE AND ADDITIONAL DEVELOPMENT SHOULD REMAIN EAST OF
ORD/MDW BUT MAY STILL IMPACT GYY THROUGH 19Z OR SO UNTIL THE FRONT
PUSHES EAST OF THERE. AS COOLER AIR ALOFT SPREADS ACROSS THE AREA
THIS AFTERNOON...THERE COULD BE SOME INSTABILITY SHOWERS...
PERHAPS ISOLATED THUNDER...FROM MID AFTERNOON THROUGH EARLY
EVENING.

WEST/NORTHWEST WINDS HAVE INCREASED INTO THE 15-20KT RANGE WITH
GUSTS INTO THE MID 20KT RANGE. WITH COOLER AND DRIER AIR ADVECTING
INTO THE REGION...LOW LEVEL MIXING WILL BE FAIRLY EFFICIENT
BRINGING STRONGER WINDS TO THE SURFACE AND BUMPED SPEEDS/GUSTS UP
JUST A BIT WITH GUSTS INTO THE UPPER 20KT RANGE POSSIBLE FOR MUCH
OF THE AFTERNOON/EARLY EVENING.

ANOTHER COLD FRONT/WIND SHIFT IS EXPECTED THIS EVENING WHICH WILL
LIKELY SHIFT WINDS TO THE NORTH/NORTHEAST. CHANGES TO TIMING MAY
BE NEEDED WITH FUTURE UPDATES BUT CONFIDENCE FOR A SHIFT TO THE
NORTH/NORTHEAST IS INCREASING. IN ADDITION...THERE COULD BE A
PERIOD OF MVFR CIGS BEHIND THIS FRONT. WINDS WILL TEND TO SHIFT
BACK NORTH/NORTHWEST OVERNIGHT...THEN SHIFT BACK NORTH/NORTHEAST
MONDAY MORNING AND REMAIN GUSTY FOR MUCH OF MONDAY. CMS

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* HIGH FOR WINDS THIS AFTERNOON...MEDIUM FOR THE REST OF THE PERIOD.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* MEDIUM FOR MVFR CIGS LATE EVENING/OVERNIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY
     IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL
     4 AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 271950
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
250 PM CDT SUN JUL 27 2014

.DISCUSSION...
250 PM CDT

COMPACT UPPER LOW OVER WISCONSIN THIS AFTERNOON CONTINUES TO DIG
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION. A COLD FRONT
TRAILING FROM ASSOCIATED SURFACE LOW OVER LOWER MICHIGAN...TRAILS
SOUTHWEST ACROSS NORTHWEST INDIANA INTO CENTRAL IL AND WAS JUST
ABOUT TO CLEAR THE SOUTHEAST CORNER OF THE CWA AT 1930Z. GUSTY
WEST-NORTHWEST WINDS UP TO 35 MPH AT TIMES WERE SPREADING DRIER AIR
INTO THE FORECAST AREA...THOUGH COLD POOL ASSOCIATED WITH UPPER LOW
WILL BRING THE POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM INTO THE NORTHEAST THIRD OR SO OF THE
FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY
EVENING HOURS. MID-LEVEL CIRCULATION MOVES OFF TO THE SOUTHEAST THIS
EVENING AND A DECREASE IN DIURNAL STRATOCU IS EXPECTED TO ACCOMPANY
COOLER WEATHER OVERNIGHT...WITH TEMPERATURES FALLING OFF INTO THE
50S FROM THE NORTHWEST.

UPPER PATTERN IS IN THE PROCESS OF EVOLVING INTO A DEEP LONG WAVE
TROUGH ACROSS EASTERN NORTH AMERICA...AND AN UPPER RIDGE IN THE
WEST. THIS SETS UP A PROLONGED PERIOD OF SLIGHTLY COOLER THAN NORMAL
WEATHER...WITH HIGHS IN THE MID-70S MONDAY...THEN GENERALLY IN THE
MID-UPPER 70S THROUGH THE REMAINDER OF THE WEEK. SOME LAKE COOLING
EXPECTED INTO NORTHWEST INDIANA AND ALONG THE IMMEDIATE IL SHORE
MONDAY WITH NORTH WINDS BECOMING SLIGHTLY NORTHEAST AS GRADIENT
WEAKENS MONDAY AFTERNOON. LOW LEVEL FLOW THEN BECOMES MORE
WEST-NORTHWEST OVER THE NEXT SEVERAL DAYS AS SURFACE HIGH PRESSURE
BUILDS THROUGH THE MISSOURI...MID-MISSISSIPPI AND OHIO VALLEYS...AND
A SERIES OF WEAK TROUGHS ROTATE THROUGH THE GREAT LAKES REGION.

SUBSIDENCE BEHIND DEPARTING UPPER LOW AND WEST OF DEEPENING LONG
WAVE TROUGH AXIS IS EXPECTED TO SUPPRESS ANY SHOWER POTENTIAL
MONDAY. GUIDANCE DEPICTS A SERIES OF MINOR SHORT WAVES ROTATING
THROUGH THE WESTERN GREAT LAKES REGION WITHIN THE WESTERN PERIPHERY
OF THE CORE OF THE UPPER TROUGH THROUGH THE WEEK HOWEVER...WITH SOME
THREAT OF SCATTERED DIURNAL SHOWERS/THUNDERSTORMS EACH DAY FROM
TUESDAY INTO SATURDAY. MODELS MAY BE A LITTLE TOO MOIST IN LOW
LEVELS GIVEN NORTH-NORTHWEST FLOW NEAR THE SURFACE THROUGH THE
PERIOD...HAVE GENERALLY MAINTAINED 20-30 PERCENT POPS FOR DAILY
SHOWER TRENDS. SOME INDICATION OF A DEEPER MID-LEVEL SHORT WAVE
FRIDAY WITH SLIGHTLY HIGHER BLENDED MODEL POPS AT THAT TIME. TROUGH
AXIS DRIFTS EAST WITH WEAK SURFACE HIGH DEPICTED OVER NEXT
WEEKEND...WITH DRY FORECAST SATURDAY NIGHT-SUNDAY.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* STRONG/GUSTY WEST/NORTHWEST WINDS THRU EARLY EVENING.
* CHANCE OF SHRA MID AFTERNOON THRU THIS EVENING.
* WIND SHIFT TO NORTH/NORTHEAST MID/LATE EVENING.
* CHANCE OF MVFR CIGS LATE EVENING/OVERNIGHT.
* GUSTY NORTH/NORTHEAST WINDS MONDAY. CMS

//DISCUSSION...UPDATED 18Z...

FRONTAL BOUNDARY JUST EAST OF ORD/MDW WITH A FEW CELLS DEVELOPING
OVER THE LAKE AND ADDITIONAL DEVELOPMENT SHOULD REMAIN EAST OF
ORD/MDW BUT MAY STILL IMPACT GYY THROUGH 19Z OR SO UNTIL THE FRONT
PUSHES EAST OF THERE. AS COOLER AIR ALOFT SPREADS ACROSS THE AREA
THIS AFTERNOON...THERE COULD BE SOME INSTABILITY SHOWERS...
PERHAPS ISOLATED THUNDER...FROM MID AFTERNOON THROUGH EARLY
EVENING.

WEST/NORTHWEST WINDS HAVE INCREASED INTO THE 15-20KT RANGE WITH
GUSTS INTO THE MID 20KT RANGE. WITH COOLER AND DRIER AIR ADVECTING
INTO THE REGION...LOW LEVEL MIXING WILL BE FAIRLY EFFICIENT
BRINGING STRONGER WINDS TO THE SURFACE AND BUMPED SPEEDS/GUSTS UP
JUST A BIT WITH GUSTS INTO THE UPPER 20KT RANGE POSSIBLE FOR MUCH
OF THE AFTERNOON/EARLY EVENING.

ANOTHER COLD FRONT/WIND SHIFT IS EXPECTED THIS EVENING WHICH WILL
LIKELY SHIFT WINDS TO THE NORTH/NORTHEAST. CHANGES TO TIMING MAY
BE NEEDED WITH FUTURE UPDATES BUT CONFIDENCE FOR A SHIFT TO THE
NORTH/NORTHEAST IS INCREASING. IN ADDITION...THERE COULD BE A
PERIOD OF MVFR CIGS BEHIND THIS FRONT. WINDS WILL TEND TO SHIFT
BACK NORTH/NORTHWEST OVERNIGHT...THEN SHIFT BACK NORTH/NORTHEAST
MONDAY MORNING AND REMAIN GUSTY FOR MUCH OF MONDAY. CMS

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* HIGH FOR WINDS THIS AFTERNOON...MEDIUM FOR THE REST OF THE PERIOD.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* MEDIUM FOR MVFR CIGS LATE EVENING/OVERNIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 271910
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
210 PM CDT SUN JUL 27 2014

.DISCUSSION...
1142 AM CDT

HAVE UPDATED FORECAST TO FOCUS SHOWER/THUNDERSTORM POTENTIAL ACROSS
FAR EASTERN CWA ALONG/AHEAD OF COLD FRONT MIDDAY/EARLY AFTERNOON...
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THEN DEVELOPING
THIS AFTERNOON WITH GREATEST COVERAGE NORTH...LESS SOUTH. MADE SOME
ADJUSTMENTS TO TEMPS AS WELL...WITH WARMER HIGHS EAST/SOUTHEAST
SETTLING BACK INTO THE MID-UPPER 70S BEHIND COLD FRONT LATER TODAY.

COLD FRONT WAS APPROACHING A CHICAGO-PONTIAC ILLINOIS LINE AT 16Z...
AND WILL CONTINUE TO PUSH EAST ACROSS NORTHWEST INDIANA AND EAST
CENTRAL ILLINOIS INTO EARLY AFTERNOON. HIGH-RES GUIDANCE HAS
CONTINUED TO DEPICT CONVECTIVE DEVELOPMENT ALONG/AHEAD OF THE FRONT
IN THE NEXT 1-2 HOURS...THOUGH WEST-SOUTHWEST WINDS AHEAD OF THE
BOUNDARY ARE RESULTING IN GENERALLY WEAK CONVERGENCE. WITH TEMPS
RISING INTO THE LOW-MID 80S AND SURFACE DEW POINT TEMPS IN THE
LOW-MID 70S AHEAD OF THE FRONT...FORECAST SOUNDINGS DO INDICATE
1000+ J/KG OF MLCAPE ALTHOUGH TREND TOWARD LATER INITIATION AND LESS
COVERAGE NOTED IN HIGH-RES MODELS. HAVE ADJUSTED SPATIAL COVERAGE OF
POPS TO FAVOR FAR EASTERN AREAS NEXT FEW HOURS AHEAD OF THE FRONT.
NOTE THAT SPC HAS REMOVED EASTERN CWA FROM SLGT RISK WITH THE
UPDATED DAY 1 OUTLOOK. IF DEEP UPDRAFTS ARE ABLE TO DEVELOP AHEAD OF
THE FRONT STILL LOOKS TO BE POTENTIAL FOR GUSTY WINDS/SMALL HAIL...
THOUGH NO ORGANIZED SEVERE THREAT MAINLY DUE TO UNFAVORABLE LOW
LEVEL CONVERGENCE.

OTHERWISE...STRONG/COMPACT UPPER LOW DIGGING SOUTHEAST ACROSS THE
WESTERN GREAT LAKES REGION THIS AFTERNOON PER WATER VAPOR IMAGERY.
RESULTING HEIGHT FALLS/COOLING ALOFT IS EXPECTED TO PRODUCE
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS ESPECIALLY
NORTHERN PARTS OF THE CWA LATER THIS AFTERNOON...WITH REGIONAL RADAR
MOSAIC ALREADY SHOWING THIS TREND ACROSS WI. INSTABILITY APPEARS TO
WEAKEN WITH TIME WITH COOL/DRY LOW LEVEL ADVECTION...SUGGESTING
LOWER COVERAGE OF THUNDER BY LATE AFTERNOON.

TEMP WISE...SOME MID-80S NOTED ALREADY ACROSS NORTHEAST IL AHEAD OF
FRONT. HAVE BUMPED MAX TEMPS A LITTLE ACROSS THE AREA AND ESPECIALLY
EAST/SOUTHEAST...WITH SOME COOLING EXPECTED BACK INTO THE UPPER 70S
OR SO THROUGH THE AFTERNOON WITH COOLER AIR ALOFT AND INCREASED
CLOUD COVER.

RATZER

//PREV DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* STRONG/GUSTY WEST/NORTHWEST WINDS THRU EARLY EVENING.
* CHANCE OF SHRA MID AFTERNOON THRU THIS EVENING.
* WIND SHIFT TO NORTH/NORTHEAST MID/LATE EVENING.
* CHANCE OF MVFR CIGS LATE EVENING/OVERNIGHT.
* GUSTY NORTH/NORTHEAST WINDS MONDAY. CMS

//DISCUSSION...UPDATED 18Z...

FRONTAL BOUNDARY JUST EAST OF ORD/MDW WITH A FEW CELLS DEVELOPING
OVER THE LAKE AND ADDITIONAL DEVELOPMENT SHOULD REMAIN EAST OF
ORD/MDW BUT MAY STILL IMPACT GYY THROUGH 19Z OR SO UNTIL THE FRONT
PUSHES EAST OF THERE. AS COOLER AIR ALOFT SPREADS ACROSS THE AREA
THIS AFTERNOON...THERE COULD BE SOME INSTABILITY SHOWERS...
PERHAPS ISOLATED THUNDER...FROM MID AFTERNOON THROUGH EARLY
EVENING.

WEST/NORTHWEST WINDS HAVE INCREASED INTO THE 15-20KT RANGE WITH
GUSTS INTO THE MID 20KT RANGE. WITH COOLER AND DRIER AIR ADVECTING
INTO THE REGION...LOW LEVEL MIXING WILL BE FAIRLY EFFICIENT
BRINGING STRONGER WINDS TO THE SURFACE AND BUMPED SPEEDS/GUSTS UP
JUST A BIT WITH GUSTS INTO THE UPPER 20KT RANGE POSSIBLE FOR MUCH
OF THE AFTERNOON/EARLY EVENING.

ANOTHER COLD FRONT/WIND SHIFT IS EXPECTED THIS EVENING WHICH WILL
LIKELY SHIFT WINDS TO THE NORTH/NORTHEAST. CHANGES TO TIMING MAY
BE NEEDED WITH FUTURE UPDATES BUT CONFIDENCE FOR A SHIFT TO THE
NORTH/NORTHEAST IS INCREASING. IN ADDITION...THERE COULD BE A
PERIOD OF MVFR CIGS BEHIND THIS FRONT. WINDS WILL TEND TO SHIFT
BACK NORTH/NORTHWEST OVERNIGHT...THEN SHIFT BACK NORTH/NORTHEAST
MONDAY MORNING AND REMAIN GUSTY FOR MUCH OF MONDAY. CMS

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* HIGH FOR WINDS THIS AFTERNOON...MEDIUM FOR THE REST OF THE PERIOD.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* MEDIUM FOR MVFR CIGS LATE EVENING/OVERNIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 271910
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
210 PM CDT SUN JUL 27 2014

.DISCUSSION...
1142 AM CDT

HAVE UPDATED FORECAST TO FOCUS SHOWER/THUNDERSTORM POTENTIAL ACROSS
FAR EASTERN CWA ALONG/AHEAD OF COLD FRONT MIDDAY/EARLY AFTERNOON...
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THEN DEVELOPING
THIS AFTERNOON WITH GREATEST COVERAGE NORTH...LESS SOUTH. MADE SOME
ADJUSTMENTS TO TEMPS AS WELL...WITH WARMER HIGHS EAST/SOUTHEAST
SETTLING BACK INTO THE MID-UPPER 70S BEHIND COLD FRONT LATER TODAY.

COLD FRONT WAS APPROACHING A CHICAGO-PONTIAC ILLINOIS LINE AT 16Z...
AND WILL CONTINUE TO PUSH EAST ACROSS NORTHWEST INDIANA AND EAST
CENTRAL ILLINOIS INTO EARLY AFTERNOON. HIGH-RES GUIDANCE HAS
CONTINUED TO DEPICT CONVECTIVE DEVELOPMENT ALONG/AHEAD OF THE FRONT
IN THE NEXT 1-2 HOURS...THOUGH WEST-SOUTHWEST WINDS AHEAD OF THE
BOUNDARY ARE RESULTING IN GENERALLY WEAK CONVERGENCE. WITH TEMPS
RISING INTO THE LOW-MID 80S AND SURFACE DEW POINT TEMPS IN THE
LOW-MID 70S AHEAD OF THE FRONT...FORECAST SOUNDINGS DO INDICATE
1000+ J/KG OF MLCAPE ALTHOUGH TREND TOWARD LATER INITIATION AND LESS
COVERAGE NOTED IN HIGH-RES MODELS. HAVE ADJUSTED SPATIAL COVERAGE OF
POPS TO FAVOR FAR EASTERN AREAS NEXT FEW HOURS AHEAD OF THE FRONT.
NOTE THAT SPC HAS REMOVED EASTERN CWA FROM SLGT RISK WITH THE
UPDATED DAY 1 OUTLOOK. IF DEEP UPDRAFTS ARE ABLE TO DEVELOP AHEAD OF
THE FRONT STILL LOOKS TO BE POTENTIAL FOR GUSTY WINDS/SMALL HAIL...
THOUGH NO ORGANIZED SEVERE THREAT MAINLY DUE TO UNFAVORABLE LOW
LEVEL CONVERGENCE.

OTHERWISE...STRONG/COMPACT UPPER LOW DIGGING SOUTHEAST ACROSS THE
WESTERN GREAT LAKES REGION THIS AFTERNOON PER WATER VAPOR IMAGERY.
RESULTING HEIGHT FALLS/COOLING ALOFT IS EXPECTED TO PRODUCE
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS ESPECIALLY
NORTHERN PARTS OF THE CWA LATER THIS AFTERNOON...WITH REGIONAL RADAR
MOSAIC ALREADY SHOWING THIS TREND ACROSS WI. INSTABILITY APPEARS TO
WEAKEN WITH TIME WITH COOL/DRY LOW LEVEL ADVECTION...SUGGESTING
LOWER COVERAGE OF THUNDER BY LATE AFTERNOON.

TEMP WISE...SOME MID-80S NOTED ALREADY ACROSS NORTHEAST IL AHEAD OF
FRONT. HAVE BUMPED MAX TEMPS A LITTLE ACROSS THE AREA AND ESPECIALLY
EAST/SOUTHEAST...WITH SOME COOLING EXPECTED BACK INTO THE UPPER 70S
OR SO THROUGH THE AFTERNOON WITH COOLER AIR ALOFT AND INCREASED
CLOUD COVER.

RATZER

//PREV DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* STRONG/GUSTY WEST/NORTHWEST WINDS THRU EARLY EVENING.
* CHANCE OF SHRA MID AFTERNOON THRU THIS EVENING.
* WIND SHIFT TO NORTH/NORTHEAST MID/LATE EVENING.
* CHANCE OF MVFR CIGS LATE EVENING/OVERNIGHT.
* GUSTY NORTH/NORTHEAST WINDS MONDAY. CMS

//DISCUSSION...UPDATED 18Z...

FRONTAL BOUNDARY JUST EAST OF ORD/MDW WITH A FEW CELLS DEVELOPING
OVER THE LAKE AND ADDITIONAL DEVELOPMENT SHOULD REMAIN EAST OF
ORD/MDW BUT MAY STILL IMPACT GYY THROUGH 19Z OR SO UNTIL THE FRONT
PUSHES EAST OF THERE. AS COOLER AIR ALOFT SPREADS ACROSS THE AREA
THIS AFTERNOON...THERE COULD BE SOME INSTABILITY SHOWERS...
PERHAPS ISOLATED THUNDER...FROM MID AFTERNOON THROUGH EARLY
EVENING.

WEST/NORTHWEST WINDS HAVE INCREASED INTO THE 15-20KT RANGE WITH
GUSTS INTO THE MID 20KT RANGE. WITH COOLER AND DRIER AIR ADVECTING
INTO THE REGION...LOW LEVEL MIXING WILL BE FAIRLY EFFICIENT
BRINGING STRONGER WINDS TO THE SURFACE AND BUMPED SPEEDS/GUSTS UP
JUST A BIT WITH GUSTS INTO THE UPPER 20KT RANGE POSSIBLE FOR MUCH
OF THE AFTERNOON/EARLY EVENING.

ANOTHER COLD FRONT/WIND SHIFT IS EXPECTED THIS EVENING WHICH WILL
LIKELY SHIFT WINDS TO THE NORTH/NORTHEAST. CHANGES TO TIMING MAY
BE NEEDED WITH FUTURE UPDATES BUT CONFIDENCE FOR A SHIFT TO THE
NORTH/NORTHEAST IS INCREASING. IN ADDITION...THERE COULD BE A
PERIOD OF MVFR CIGS BEHIND THIS FRONT. WINDS WILL TEND TO SHIFT
BACK NORTH/NORTHWEST OVERNIGHT...THEN SHIFT BACK NORTH/NORTHEAST
MONDAY MORNING AND REMAIN GUSTY FOR MUCH OF MONDAY. CMS

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* HIGH FOR WINDS THIS AFTERNOON...MEDIUM FOR THE REST OF THE PERIOD.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* MEDIUM FOR MVFR CIGS LATE EVENING/OVERNIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
210 PM CDT

AN ACTIVE PERIOD OF WEATHER IN UNDERWAY OVER LAKE MICHIGAN.
DEEPENING LOW PRESSURE HAS PASSED ACROSS NORTHERN LAKE MICHIGAN
AND IS MOVING THROUGH LOWER MICHIGAN THIS AFTERNOON TO THE EASTERN
GREAT LAKES THIS EVENING. FOLLOWING THE PASSAGE OF THIS LOW AND AN
ASSOCIATED COLD FRONT...STRENGTHENING NORTHWEST WINDS ARE
FILTERING ACROSS THE LAKE AND QUICKLY INCREASING TO 20-25KT WITH
OCNL GUSTS TO 30KT AND SCATTERED THUNDERSTORMS. THE SCATTERED
THUNDERSTORMS SHOULD CONTINUE INTO THE EVENING WHILE WINDS
GRADUALLY VEER MORE NORTHERLY AND INCREASE TO PREVAILING 30KT.
OCNL GALE FORCE GUSTS TO 35 KT ARE POSSIBLE...BUT SHOULD NOT BE
PERSISTENT ENOUGH TO NECESSITATE A GALE WARNING. SMALL CRAFT
ADVISORIES HAVE ALREADY BEEN HOISTED FOR THE ILLINOIS AND INDIANA
NEARSHORE WATERS AND NO CHANGE HAS BEEN MADE TO THE TIMING
DETAILS. HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS THIS
AFTERNOON AND SHOULD BEGIN TO SPREAD ACROSS THE WESTERN GREAT
LAKES MONDAY. AS THE HIGH SPREADS ACROSS THE LAKE LATE
MONDAY...WINDS SHOULD DIMINISH QUICKLY. ON TUESDAY...A SFC TROUGH
OR OR WEAK COLD FRONT TRACKING SOUTH DOWN THE LAKE WILL BRING A
REINFORCING SHOT OF COOLER AIR...BRINGING A BRIEF INCREASE TO NWLY
WINDS TUESDAY MORNING. FOLLOWING THE PASSAGE OF THIS WEAK
TROUGH/COLD FRONT...THE HIGH PRESSURE WILL SPREAD ACROSS THE
WESTERN GREAT LAKES TO THE OHIO VALLEY BY WEDNESDAY. HIGH PRESSURE
WILL BE THE DOMINANT FEATURE OVER THE GREAT LAKES REGION FROM MID
WEEK INTO THE WEEKEND...SETTING UP A PERIOD OF QUIET WEATHER WITH
LIGHT AND VARIABLE WINDS AND MINIMAL WAVE ACTION.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 271746
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1246 PM CDT SUN JUL 27 2014

.DISCUSSION...
1142 AM CDT

HAVE UPDATED FORECAST TO FOCUS SHOWER/THUNDERSTORM POTENTIAL ACROSS
FAR EASTERN CWA ALONG/AHEAD OF COLD FRONT MIDDAY/EARLY AFTERNOON...
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THEN DEVELOPING
THIS AFTERNOON WITH GREATEST COVERAGE NORTH...LESS SOUTH. MADE SOME
ADJUSTMENTS TO TEMPS AS WELL...WITH WARMER HIGHS EAST/SOUTHEAST
SETTLING BACK INTO THE MID-UPPER 70S BEHIND COLD FRONT LATER TODAY.

COLD FRONT WAS APPROACHING A CHICAGO-PONTIAC ILLINOIS LINE AT 16Z...
AND WILL CONTINUE TO PUSH EAST ACROSS NORTHWEST INDIANA AND EAST
CENTRAL ILLINOIS INTO EARLY AFTERNOON. HIGH-RES GUIDANCE HAS
CONTINUED TO DEPICT CONVECTIVE DEVELOPMENT ALONG/AHEAD OF THE FRONT
IN THE NEXT 1-2 HOURS...THOUGH WEST-SOUTHWEST WINDS AHEAD OF THE
BOUNDARY ARE RESULTING IN GENERALLY WEAK CONVERGENCE. WITH TEMPS
RISING INTO THE LOW-MID 80S AND SURFACE DEW POINT TEMPS IN THE
LOW-MID 70S AHEAD OF THE FRONT...FORECAST SOUNDINGS DO INDICATE
1000+ J/KG OF MLCAPE ALTHOUGH TREND TOWARD LATER INITIATION AND LESS
COVERAGE NOTED IN HIGH-RES MODELS. HAVE ADJUSTED SPATIAL COVERAGE OF
POPS TO FAVOR FAR EASTERN AREAS NEXT FEW HOURS AHEAD OF THE FRONT.
NOTE THAT SPC HAS REMOVED EASTERN CWA FROM SLGT RISK WITH THE
UPDATED DAY 1 OUTLOOK. IF DEEP UPDRAFTS ARE ABLE TO DEVELOP AHEAD OF
THE FRONT STILL LOOKS TO BE POTENTIAL FOR GUSTY WINDS/SMALL HAIL...
THOUGH NO ORGANIZED SEVERE THREAT MAINLY DUE TO UNFAVORABLE LOW
LEVEL CONVERGENCE.

OTHERWISE...STRONG/COMPACT UPPER LOW DIGGING SOUTHEAST ACROSS THE
WESTERN GREAT LAKES REGION THIS AFTERNOON PER WATER VAPOR IMAGERY.
RESULTING HEIGHT FALLS/COOLING ALOFT IS EXPECTED TO PRODUCE
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS ESPECIALLY
NORTHERN PARTS OF THE CWA LATER THIS AFTERNOON...WITH REGIONAL RADAR
MOSAIC ALREADY SHOWING THIS TREND ACROSS WI. INSTABILITY APPEARS TO
WEAKEN WITH TIME WITH COOL/DRY LOW LEVEL ADVECTION...SUGGESTING
LOWER COVERAGE OF THUNDER BY LATE AFTERNOON.

TEMP WISE...SOME MID-80S NOTED ALREADY ACROSS NORTHEAST IL AHEAD OF
FRONT. HAVE BUMPED MAX TEMPS A LITTLE ACROSS THE AREA AND ESPECIALLY
EAST/SOUTHEAST...WITH SOME COOLING EXPECTED BACK INTO THE UPPER 70S
OR SO THROUGH THE AFTERNOON WITH COOLER AIR ALOFT AND INCREASED
CLOUD COVER.

RATZER

//PREV DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* STRONG/GUSTY WEST/NORTHWEST WINDS THRU EARLY EVENING.
* CHANCE OF SHRA MID AFTERNOON THRU THIS EVENING.
* WIND SHIFT TO NORTH/NORTHEAST MID/LATE EVENING.
* CHANCE OF MVFR CIGS LATE EVENING/OVERNIGHT.
* GUSTY NORTH/NORTHEAST WINDS MONDAY. CMS

//DISCUSSION...UPDATED 18Z...

FRONTAL BOUNDARY JUST EAST OF ORD/MDW WITH A FEW CELLS DEVELOPING
OVER THE LAKE AND ADDITIONAL DEVELOPMENT SHOULD REMAIN EAST OF
ORD/MDW BUT MAY STILL IMPACT GYY THROUGH 19Z OR SO UNTIL THE FRONT
PUSHES EAST OF THERE. AS COOLER AIR ALOFT SPREADS ACROSS THE AREA
THIS AFTERNOON...THERE COULD BE SOME INSTABILITY SHOWERS...
PERHAPS ISOLATED THUNDER...FROM MID AFTERNOON THROUGH EARLY
EVENING.

WEST/NORTHWEST WINDS HAVE INCREASED INTO THE 15-20KT RANGE WITH
GUSTS INTO THE MID 20KT RANGE. WITH COOLER AND DRIER AIR ADVECTING
INTO THE REGION...LOW LEVEL MIXING WILL BE FAIRLY EFFICIENT
BRINGING STRONGER WINDS TO THE SURFACE AND BUMPED SPEEDS/GUSTS UP
JUST A BIT WITH GUSTS INTO THE UPPER 20KT RANGE POSSIBLE FOR MUCH
OF THE AFTERNOON/EARLY EVENING.

ANOTHER COLD FRONT/WIND SHIFT IS EXPECTED THIS EVENING WHICH WILL
LIKELY SHIFT WINDS TO THE NORTH/NORTHEAST. CHANGES TO TIMING MAY
BE NEEDED WITH FUTURE UPDATES BUT CONFIDENCE FOR A SHIFT TO THE
NORTH/NORTHEAST IS INCREASING. IN ADDITION...THERE COULD BE A
PERIOD OF MVFR CIGS BEHIND THIS FRONT. WINDS WILL TEND TO SHIFT
BACK NORTH/NORTHWEST OVERNIGHT...THEN SHIFT BACK NORTH/NORTHEAST
MONDAY MORNING AND REMAIN GUSTY FOR MUCH OF MONDAY. CMS

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* HIGH FOR WINDS THIS AFTERNOON...MEDIUM FOR THE REST OF THE PERIOD.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* MEDIUM FOR MVFR CIGS LATE EVENING/OVERNIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS
     UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL
     4 AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 271643
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1143 AM CDT SUN JUL 27 2014

.DISCUSSION...
1142 AM CDT

HAVE UPDATED FORECAST TO FOCUS SHOWER/THUNDERSTORM POTENTIAL ACROSS
FAR EASTERN CWA ALONG/AHEAD OF COLD FRONT MIDDAY/EARLY AFTERNOON...
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THEN DEVELOPING
THIS AFTERNOON WITH GREATEST COVERAGE NORTH...LESS SOUTH. MADE SOME
ADJUSTMENTS TO TEMPS AS WELL...WITH WARMER HIGHS EAST/SOUTHEAST
SETTLING BACK INTO THE MID-UPPER 70S BEHIND COLD FRONT LATER TODAY.

COLD FRONT WAS APPROACHING A CHICAGO-PONTIAC ILLINOIS LINE AT 16Z...
AND WILL CONTINUE TO PUSH EAST ACROSS NORTHWEST INDIANA AND EAST
CENTRAL ILLINOIS INTO EARLY AFTERNOON. HIGH-RES GUIDANCE HAS
CONTINUED TO DEPICT CONVECTIVE DEVELOPMENT ALONG/AHEAD OF THE FRONT
IN THE NEXT 1-2 HOURS...THOUGH WEST-SOUTHWEST WINDS AHEAD OF THE
BOUNDARY ARE RESULTING IN GENERALLY WEAK CONVERGENCE. WITH TEMPS
RISING INTO THE LOW-MID 80S AND SURFACE DEW POINT TEMPS IN THE
LOW-MID 70S AHEAD OF THE FRONT...FORECAST SOUNDINGS DO INDICATE
1000+ J/KG OF MLCAPE ALTHOUGH TREND TOWARD LATER INITIATION AND LESS
COVERAGE NOTED IN HIGH-RES MODELS. HAVE ADJUSTED SPATIAL COVERAGE OF
POPS TO FAVOR FAR EASTERN AREAS NEXT FEW HOURS AHEAD OF THE FRONT.
NOTE THAT SPC HAS REMOVED EASTERN CWA FROM SLGT RISK WITH THE
UPDATED DAY 1 OUTLOOK. IF DEEP UPDRAFTS ARE ABLE TO DEVELOP AHEAD OF
THE FRONT STILL LOOKS TO BE POTENTIAL FOR GUSTY WINDS/SMALL HAIL...
THOUGH NO ORGANIZED SEVERE THREAT MAINLY DUE TO UNFAVORABLE LOW
LEVEL CONVERGENCE.

OTHERWISE...STRONG/COMPACT UPPER LOW DIGGING SOUTHEAST ACROSS THE
WESTERN GREAT LAKES REGION THIS AFTERNOON PER WATER VAPOR IMAGERY.
RESULTING HEIGHT FALLS/COOLING ALOFT IS EXPECTED TO PRODUCE
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS ESPECIALLY
NORTHERN PARTS OF THE CWA LATER THIS AFTERNOON...WITH REGIONAL RADAR
MOSAIC ALREADY SHOWING THIS TREND ACROSS WI. INSTABILITY APPEARS TO
WEAKEN WITH TIME WITH COOL/DRY LOW LEVEL ADVECTION...SUGGESTING
LOWER COVERAGE OF THUNDER BY LATE AFTERNOON.

TEMP WISE...SOME MID-80S NOTED ALREADY ACROSS NORTHEAST IL AHEAD OF
FRONT. HAVE BUMPED MAX TEMPS A LITTLE ACROSS THE AREA AND ESPECIALLY
EAST/SOUTHEAST...WITH SOME COOLING EXPECTED BACK INTO THE UPPER 70S
OR SO THROUGH THE AFTERNOON WITH COOLER AIR ALOFT AND INCREASED
CLOUD COVER.

RATZER

&&

.PREV DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* ISOLATED/SCATTERED TSRA 16Z-18Z.
* CHANCE OF SHRA THIS AFTERNOON INTO EARLY THIS EVENING.
* STRONG/GUSTY WEST/NORTHWEST WINDS LATE MORNING THRU THIS EVENING.
* NORTH/NORTHEAST WINDS MONDAY MORNING.
* POSSIBLE MVFR CIGS TONIGHT. CMS

//DISCUSSION...UPDATED 16Z...

FRONTAL BOUNDARY IS NOW PUSHING ACROSS THE CHICAGO METRO AREA AND
ANY TSRA THAT MAY FORM ALONG/AHEAD OF THIS FRONT WILL BE SHORT-
LIVED IN TERMS OF IMPACTS AT THE TERMINALS. HAVE TRIMMED TEMPO
DURATION AND ALSO VCTS DURATION...NOW ENDING AT ORD/MDW BY 18Z.
THOUGH ITS STILL POSSIBLE THAT A FAIRLY BROKEN/SOLID LINE OF TSRA
DEVELOPS EAST OF THE TERMINALS BY EARLY AFTERNOON. OTHERWISE...
WEST/NORTHWEST WINDS WILL CONTINUE TO INCREASE WITH GUSTS INTO THE
MID 20KT RANGE FOR MUCH OF THE AFTERNOON. CMS

PREVIOUS 12Z DISCUSSION...

HIGH MOISTURE VALUES OVER THE AREA WILL SUPPORT FOG/LOW CLOUDS
THROUGH 13Z-14Z AND MAYBE EVEN TO 15Z ACROSS THE REGION. WOULD NOT
EXPECT CONDITIONS TO GET WORSE AT TAF SITES AFTER 12Z GIVEN
DAYBREAK AND AN INCREASING WIND FLOW.

A STRONG UPPER LEVEL LOW PRESSURE MOVING INTO NORTHWEST WI AS OF
12Z WILL ROTATE SOUTHEASTWARD OVER CHICAGO BY MID-AFTERNOON. JUST
AHEAD OF THIS WILL EXIST A FAIR AMOUNT OF LIFT AND UPPER
SUPPORT...WHICH OVERRIDING A COLD FRONT WITH INSTABILITY ALONG IT
WILL LIKELY SUPPORT THE DEVELOPMENT OF A LINE OF SHRA/TSRA. HOW
FAR SOUTH THIS WILL EXTEND IS UNCERTAIN BUT AT THIS TIME BELIEVE
ENOUGH THAT IT WARRANTS INCLUSION INTO THE TAF. AS THE HEART OF
THE UPPER LOW MOVES OVER THE AREA DURING THE MID TO LATE
AFTERNOON...WOULD EXPECT SCATTERED SHOWERS WITH POSSIBLY ISOLATED
STORMS.

BEHIND THE COLD FRONTAL PASSAGE LATE THIS MORNING/EARLY
AFTERNOON...THERE WILL BE A SHARP INCREASE IN THE WIND SPEEDS
FROM THE WEST-NORTHWEST. OCCASIONAL GUSTS IN EXCESS OF 25 KT ARE
PROBABLE. A SECONDARY COLD FRONT DROPPING SOUTHWARD LATE THIS
AFTERNOON WILL LIKELY KEEP SOME GUSTS INTO THE EVENING PERIOD DUE
TO ITS COOL AIR ADVECTION. THIS FRONT WILL ALSO LIKELY PROVIDE
SOME FOCUS FOR MVFR OR NEAR-MVFR CLOUDS THIS EVENING INTO EARLY
OVERNIGHT.

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* LOW FOR TSRA 16Z-18Z.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* HIGH FOR WINDS THROUGH THIS AFTERNOON...MEDIUM TONIGHT/MONDAY.
* LOW FOR MVFR CIGS TONIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 271643
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1143 AM CDT SUN JUL 27 2014

.DISCUSSION...
1142 AM CDT

HAVE UPDATED FORECAST TO FOCUS SHOWER/THUNDERSTORM POTENTIAL ACROSS
FAR EASTERN CWA ALONG/AHEAD OF COLD FRONT MIDDAY/EARLY AFTERNOON...
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THEN DEVELOPING
THIS AFTERNOON WITH GREATEST COVERAGE NORTH...LESS SOUTH. MADE SOME
ADJUSTMENTS TO TEMPS AS WELL...WITH WARMER HIGHS EAST/SOUTHEAST
SETTLING BACK INTO THE MID-UPPER 70S BEHIND COLD FRONT LATER TODAY.

COLD FRONT WAS APPROACHING A CHICAGO-PONTIAC ILLINOIS LINE AT 16Z...
AND WILL CONTINUE TO PUSH EAST ACROSS NORTHWEST INDIANA AND EAST
CENTRAL ILLINOIS INTO EARLY AFTERNOON. HIGH-RES GUIDANCE HAS
CONTINUED TO DEPICT CONVECTIVE DEVELOPMENT ALONG/AHEAD OF THE FRONT
IN THE NEXT 1-2 HOURS...THOUGH WEST-SOUTHWEST WINDS AHEAD OF THE
BOUNDARY ARE RESULTING IN GENERALLY WEAK CONVERGENCE. WITH TEMPS
RISING INTO THE LOW-MID 80S AND SURFACE DEW POINT TEMPS IN THE
LOW-MID 70S AHEAD OF THE FRONT...FORECAST SOUNDINGS DO INDICATE
1000+ J/KG OF MLCAPE ALTHOUGH TREND TOWARD LATER INITIATION AND LESS
COVERAGE NOTED IN HIGH-RES MODELS. HAVE ADJUSTED SPATIAL COVERAGE OF
POPS TO FAVOR FAR EASTERN AREAS NEXT FEW HOURS AHEAD OF THE FRONT.
NOTE THAT SPC HAS REMOVED EASTERN CWA FROM SLGT RISK WITH THE
UPDATED DAY 1 OUTLOOK. IF DEEP UPDRAFTS ARE ABLE TO DEVELOP AHEAD OF
THE FRONT STILL LOOKS TO BE POTENTIAL FOR GUSTY WINDS/SMALL HAIL...
THOUGH NO ORGANIZED SEVERE THREAT MAINLY DUE TO UNFAVORABLE LOW
LEVEL CONVERGENCE.

OTHERWISE...STRONG/COMPACT UPPER LOW DIGGING SOUTHEAST ACROSS THE
WESTERN GREAT LAKES REGION THIS AFTERNOON PER WATER VAPOR IMAGERY.
RESULTING HEIGHT FALLS/COOLING ALOFT IS EXPECTED TO PRODUCE
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS ESPECIALLY
NORTHERN PARTS OF THE CWA LATER THIS AFTERNOON...WITH REGIONAL RADAR
MOSAIC ALREADY SHOWING THIS TREND ACROSS WI. INSTABILITY APPEARS TO
WEAKEN WITH TIME WITH COOL/DRY LOW LEVEL ADVECTION...SUGGESTING
LOWER COVERAGE OF THUNDER BY LATE AFTERNOON.

TEMP WISE...SOME MID-80S NOTED ALREADY ACROSS NORTHEAST IL AHEAD OF
FRONT. HAVE BUMPED MAX TEMPS A LITTLE ACROSS THE AREA AND ESPECIALLY
EAST/SOUTHEAST...WITH SOME COOLING EXPECTED BACK INTO THE UPPER 70S
OR SO THROUGH THE AFTERNOON WITH COOLER AIR ALOFT AND INCREASED
CLOUD COVER.

RATZER

&&

.PREV DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* ISOLATED/SCATTERED TSRA 16Z-18Z.
* CHANCE OF SHRA THIS AFTERNOON INTO EARLY THIS EVENING.
* STRONG/GUSTY WEST/NORTHWEST WINDS LATE MORNING THRU THIS EVENING.
* NORTH/NORTHEAST WINDS MONDAY MORNING.
* POSSIBLE MVFR CIGS TONIGHT. CMS

//DISCUSSION...UPDATED 16Z...

FRONTAL BOUNDARY IS NOW PUSHING ACROSS THE CHICAGO METRO AREA AND
ANY TSRA THAT MAY FORM ALONG/AHEAD OF THIS FRONT WILL BE SHORT-
LIVED IN TERMS OF IMPACTS AT THE TERMINALS. HAVE TRIMMED TEMPO
DURATION AND ALSO VCTS DURATION...NOW ENDING AT ORD/MDW BY 18Z.
THOUGH ITS STILL POSSIBLE THAT A FAIRLY BROKEN/SOLID LINE OF TSRA
DEVELOPS EAST OF THE TERMINALS BY EARLY AFTERNOON. OTHERWISE...
WEST/NORTHWEST WINDS WILL CONTINUE TO INCREASE WITH GUSTS INTO THE
MID 20KT RANGE FOR MUCH OF THE AFTERNOON. CMS

PREVIOUS 12Z DISCUSSION...

HIGH MOISTURE VALUES OVER THE AREA WILL SUPPORT FOG/LOW CLOUDS
THROUGH 13Z-14Z AND MAYBE EVEN TO 15Z ACROSS THE REGION. WOULD NOT
EXPECT CONDITIONS TO GET WORSE AT TAF SITES AFTER 12Z GIVEN
DAYBREAK AND AN INCREASING WIND FLOW.

A STRONG UPPER LEVEL LOW PRESSURE MOVING INTO NORTHWEST WI AS OF
12Z WILL ROTATE SOUTHEASTWARD OVER CHICAGO BY MID-AFTERNOON. JUST
AHEAD OF THIS WILL EXIST A FAIR AMOUNT OF LIFT AND UPPER
SUPPORT...WHICH OVERRIDING A COLD FRONT WITH INSTABILITY ALONG IT
WILL LIKELY SUPPORT THE DEVELOPMENT OF A LINE OF SHRA/TSRA. HOW
FAR SOUTH THIS WILL EXTEND IS UNCERTAIN BUT AT THIS TIME BELIEVE
ENOUGH THAT IT WARRANTS INCLUSION INTO THE TAF. AS THE HEART OF
THE UPPER LOW MOVES OVER THE AREA DURING THE MID TO LATE
AFTERNOON...WOULD EXPECT SCATTERED SHOWERS WITH POSSIBLY ISOLATED
STORMS.

BEHIND THE COLD FRONTAL PASSAGE LATE THIS MORNING/EARLY
AFTERNOON...THERE WILL BE A SHARP INCREASE IN THE WIND SPEEDS
FROM THE WEST-NORTHWEST. OCCASIONAL GUSTS IN EXCESS OF 25 KT ARE
PROBABLE. A SECONDARY COLD FRONT DROPPING SOUTHWARD LATE THIS
AFTERNOON WILL LIKELY KEEP SOME GUSTS INTO THE EVENING PERIOD DUE
TO ITS COOL AIR ADVECTION. THIS FRONT WILL ALSO LIKELY PROVIDE
SOME FOCUS FOR MVFR OR NEAR-MVFR CLOUDS THIS EVENING INTO EARLY
OVERNIGHT.

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* LOW FOR TSRA 16Z-18Z.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* HIGH FOR WINDS THROUGH THIS AFTERNOON...MEDIUM TONIGHT/MONDAY.
* LOW FOR MVFR CIGS TONIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 271602
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1102 AM CDT SUN JUL 27 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* ISOLATED/SCATTERED TSRA 16Z-18Z.
* CHANCE OF SHRA THIS AFTERNOON INTO EARLY THIS EVENING.
* STRONG/GUSTY WEST/NORTHWEST WINDS LATE MORNING THRU THIS EVENING.
* NORTH/NORTHEAST WINDS MONDAY MORNING.
* POSSIBLE MVFR CIGS TONIGHT. CMS

//DISCUSSION...UPDATED 16Z...

FRONTAL BOUNDARY IS NOW PUSHING ACROSS THE CHICAGO METRO AREA AND
ANY TSRA THAT MAY FORM ALONG/AHEAD OF THIS FRONT WILL BE SHORT-
LIVED IN TERMS OF IMPACTS AT THE TERMINALS. HAVE TRIMMED TEMPO
DURATION AND ALSO VCTS DURATION...NOW ENDING AT ORD/MDW BY 18Z.
THOUGH ITS STILL POSSIBLE THAT A FAIRLY BROKEN/SOLID LINE OF TSRA
DEVELOPS EAST OF THE TERMINALS BY EARLY AFTERNOON. OTHERWISE...
WEST/NORTHWEST WINDS WILL CONTINUE TO INCREASE WITH GUSTS INTO THE
MID 20KT RANGE FOR MUCH OF THE AFTERNOON. CMS

PREVIOUS 12Z DISCUSSION...

HIGH MOISTURE VALUES OVER THE AREA WILL SUPPORT FOG/LOW CLOUDS
THROUGH 13Z-14Z AND MAYBE EVEN TO 15Z ACROSS THE REGION. WOULD NOT
EXPECT CONDITIONS TO GET WORSE AT TAF SITES AFTER 12Z GIVEN
DAYBREAK AND AN INCREASING WIND FLOW.

A STRONG UPPER LEVEL LOW PRESSURE MOVING INTO NORTHWEST WI AS OF
12Z WILL ROTATE SOUTHEASTWARD OVER CHICAGO BY MID-AFTERNOON. JUST
AHEAD OF THIS WILL EXIST A FAIR AMOUNT OF LIFT AND UPPER
SUPPORT...WHICH OVERRIDING A COLD FRONT WITH INSTABILITY ALONG IT
WILL LIKELY SUPPORT THE DEVELOPMENT OF A LINE OF SHRA/TSRA. HOW
FAR SOUTH THIS WILL EXTEND IS UNCERTAIN BUT AT THIS TIME BELIEVE
ENOUGH THAT IT WARRANTS INCLUSION INTO THE TAF. AS THE HEART OF
THE UPPER LOW MOVES OVER THE AREA DURING THE MID TO LATE
AFTERNOON...WOULD EXPECT SCATTERED SHOWERS WITH POSSIBLY ISOLATED
STORMS.

BEHIND THE COLD FRONTAL PASSAGE LATE THIS MORNING/EARLY
AFTERNOON...THERE WILL BE A SHARP INCREASE IN THE WIND SPEEDS
FROM THE WEST-NORTHWEST. OCCASIONAL GUSTS IN EXCESS OF 25 KT ARE
PROBABLE. A SECONDARY COLD FRONT DROPPING SOUTHWARD LATE THIS
AFTERNOON WILL LIKELY KEEP SOME GUSTS INTO THE EVENING PERIOD DUE
TO ITS COOL AIR ADVECTION. THIS FRONT WILL ALSO LIKELY PROVIDE
SOME FOCUS FOR MVFR OR NEAR-MVFR CLOUDS THIS EVENING INTO EARLY
OVERNIGHT.

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* LOW FOR TSRA 16Z-18Z.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* HIGH FOR WINDS THROUGH THIS AFTERNOON...MEDIUM TONIGHT/MONDAY.
* LOW FOR MVFR CIGS TONIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS `
     UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 271407
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
907 AM CDT SUN JUL 27 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 14Z...

* SCATTERED TSRA 16Z-19Z.
* CHANCE OF SHRA THIS AFTERNOON INTO EARLY THIS EVENING.
* STRONG/GUSTY WEST/NORTHWEST WINDS LATE MORNING THRU THIS EVENING.
* NORTH/NORTHEAST WINDS MONDAY MORNING.
* POSSIBLE MVFR CIGS TONIGHT. CMS

//DISCUSSION...UPDATED 12Z...

HIGH MOISTURE VALUES OVER THE AREA WILL SUPPORT FOG/LOW CLOUDS
THROUGH 13Z-14Z AND MAYBE EVEN TO 15Z ACROSS THE REGION. WOULD NOT
EXPECT CONDITIONS TO GET WORSE AT TAF SITES AFTER 12Z GIVEN
DAYBREAK AND AN INCREASING WIND FLOW.

A STRONG UPPER LEVEL LOW PRESSURE MOVING INTO NORTHWEST WI AS OF
12Z WILL ROTATE SOUTHEASTWARD OVER CHICAGO BY MID-AFTERNOON. JUST
AHEAD OF THIS WILL EXIST A FAIR AMOUNT OF LIFT AND UPPER
SUPPORT...WHICH OVERRIDING A COLD FRONT WITH INSTABILITY ALONG IT
WILL LIKELY SUPPORT THE DEVELOPMENT OF A LINE OF SHRA/TSRA. HOW
FAR SOUTH THIS WILL EXTEND IS UNCERTAIN BUT AT THIS TIME BELIEVE
ENOUGH THAT IT WARRANTS INCLUSION INTO THE TAF. AS THE HEART OF
THE UPPER LOW MOVES OVER THE AREA DURING THE MID TO LATE
AFTERNOON...WOULD EXPECT SCATTERED SHOWERS WITH POSSIBLY ISOLATED
STORMS.

BEHIND THE COLD FRONTAL PASSAGE LATE THIS MORNING/EARLY
AFTERNOON...THERE WILL BE A SHARP INCREASE IN THE WIND SPEEDS
FROM THE WEST-NORTHWEST. OCCASIONAL GUSTS IN EXCESS OF 25 KT ARE
PROBABLE. A SECONDARY COLD FRONT DROPPING SOUTHWARD LATE THIS
AFTERNOON WILL LIKELY KEEP SOME GUSTS INTO THE EVENING PERIOD DUE
TO ITS COOL AIR ADVECTION. THIS FRONT WILL ALSO LIKELY PROVIDE
SOME FOCUS FOR MVFR OR NEAR-MVFR CLOUDS THIS EVENING INTO EARLY
OVERNIGHT.

//ORD AND MDW CONFIDENCE...UPDATED 14Z...

* MEDIUM FOR TSRA 16Z-19Z.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* HIGH FOR WINDS THROUGH THIS AFTERNOON...MEDIUM TONIGHT/MONDAY.
* LOW FOR MVFR CIGS TONIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS
     UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 271407
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
907 AM CDT SUN JUL 27 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 14Z...

* SCATTERED TSRA 16Z-19Z.
* CHANCE OF SHRA THIS AFTERNOON INTO EARLY THIS EVENING.
* STRONG/GUSTY WEST/NORTHWEST WINDS LATE MORNING THRU THIS EVENING.
* NORTH/NORTHEAST WINDS MONDAY MORNING.
* POSSIBLE MVFR CIGS TONIGHT. CMS

//DISCUSSION...UPDATED 12Z...

HIGH MOISTURE VALUES OVER THE AREA WILL SUPPORT FOG/LOW CLOUDS
THROUGH 13Z-14Z AND MAYBE EVEN TO 15Z ACROSS THE REGION. WOULD NOT
EXPECT CONDITIONS TO GET WORSE AT TAF SITES AFTER 12Z GIVEN
DAYBREAK AND AN INCREASING WIND FLOW.

A STRONG UPPER LEVEL LOW PRESSURE MOVING INTO NORTHWEST WI AS OF
12Z WILL ROTATE SOUTHEASTWARD OVER CHICAGO BY MID-AFTERNOON. JUST
AHEAD OF THIS WILL EXIST A FAIR AMOUNT OF LIFT AND UPPER
SUPPORT...WHICH OVERRIDING A COLD FRONT WITH INSTABILITY ALONG IT
WILL LIKELY SUPPORT THE DEVELOPMENT OF A LINE OF SHRA/TSRA. HOW
FAR SOUTH THIS WILL EXTEND IS UNCERTAIN BUT AT THIS TIME BELIEVE
ENOUGH THAT IT WARRANTS INCLUSION INTO THE TAF. AS THE HEART OF
THE UPPER LOW MOVES OVER THE AREA DURING THE MID TO LATE
AFTERNOON...WOULD EXPECT SCATTERED SHOWERS WITH POSSIBLY ISOLATED
STORMS.

BEHIND THE COLD FRONTAL PASSAGE LATE THIS MORNING/EARLY
AFTERNOON...THERE WILL BE A SHARP INCREASE IN THE WIND SPEEDS
FROM THE WEST-NORTHWEST. OCCASIONAL GUSTS IN EXCESS OF 25 KT ARE
PROBABLE. A SECONDARY COLD FRONT DROPPING SOUTHWARD LATE THIS
AFTERNOON WILL LIKELY KEEP SOME GUSTS INTO THE EVENING PERIOD DUE
TO ITS COOL AIR ADVECTION. THIS FRONT WILL ALSO LIKELY PROVIDE
SOME FOCUS FOR MVFR OR NEAR-MVFR CLOUDS THIS EVENING INTO EARLY
OVERNIGHT.

//ORD AND MDW CONFIDENCE...UPDATED 14Z...

* MEDIUM FOR TSRA 16Z-19Z.
* LOW FOR SHRA THIS AFTERNOON/EARLY EVENING.
* HIGH FOR WINDS THROUGH THIS AFTERNOON...MEDIUM TONIGHT/MONDAY.
* LOW FOR MVFR CIGS TONIGHT. CMS

//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS
     UNTIL 10 PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743 UNTIL 4 AM TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 271146
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
646 AM CDT SUN JUL 27 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 12Z...

* TEMPORARY IFR/LIFR CIGS AT MAINLY ORD THROUGH 14Z.
* MVFR FOG AT BOTH AIRPORTS THROUGH 13Z-14Z.
* SCATTERED/AREA OF TSRA LATE THIS MORNING/EARLY THIS AFTERNOON WITH
  SCATTERED SHOWERS AFTERWARD.
* GUSTY WEST-NORTHWEST WINDS TODAY.
* NORTH-NORTHEAST WINDS MONDAY MORNING.
* POSSIBLE MVFR CIGS TONIGHT.



//DISCUSSION...UPDATED 12Z...

HIGH MOISTURE VALUES OVER THE AREA WILL SUPPORT FOG/LOW CLOUDS
THROUGH 13Z-14Z AND MAYBE EVEN TO 15Z ACROSS THE REGION. WOULD NOT
EXPECT CONDITIONS TO GET WORSE AT TAF SITES AFTER 12Z GIVEN
DAYBREAK AND AN INCREASING WIND FLOW.

A STRONG UPPER LEVEL LOW PRESSURE MOVING INTO NORTHWEST WI AS OF
12Z WILL ROTATE SOUTHEASTWARD OVER CHICAGO BY MID-AFTERNOON. JUST
AHEAD OF THIS WILL EXIST A FAIR AMOUNT OF LIFT AND UPPER
SUPPORT...WHICH OVERRIDING A COLD FRONT WITH INSTABILITY ALONG IT
WILL LIKELY SUPPORT THE DEVELOPMENT OF A LINE OF SHRA/TSRA. HOW
FAR SOUTH THIS WILL EXTEND IS UNCERTAIN BUT AT THIS TIME BELIEVE
ENOUGH THAT IT WARRANTS INCLUSION INTO THE TAF. AS THE HEART OF
THE UPPER LOW MOVES OVER THE AREA DURING THE MID TO LATE
AFTERNOON...WOULD EXPECT SCATTERED SHOWERS WITH POSSIBLY ISOLATED
STORMS.

BEHIND THE COLD FRONTAL PASSAGE LATE THIS MORNING/EARLY
AFTERNOON...THERE WILL BE A SHARP INCREASE IN THE WIND SPEEDS
FROM THE WEST-NORTHWEST. OCCASIONAL GUSTS IN EXCESS OF 25 KT ARE
PROBABLE. A SECONDARY COLD FRONT DROPPING SOUTHWARD LATE THIS
AFTERNOON WILL LIKELY KEEP SOME GUSTS INTO THE EVENING PERIOD DUE
TO ITS COOL AIR ADVECTION. THIS FRONT WILL ALSO LIKELY PROVIDE
SOME FOCUS FOR MVFR OR NEAR-MVFR CLOUDS THIS EVENING INTO EARLY
OVERNIGHT.


//ORD AND MDW CONFIDENCE...UPDATED 12Z...

* MEDIUM IN MVFR VISIBILITY DURATION AND LOW IN IFR CIG DURATION
  THIS MORNING.
* MEDIUM IN TSRA OCCURRING LATE THIS MORNING/EARLY THIS AFTERNOON.
  MEDIUM IN TIMING.
* HIGH IN WIND DIRECTION TODAY AND THIS EVENING...MEDIUM LATE
  TONIGHT AND MONDAY. MEDIUM IN SPEED.
* LOW IN HOW FAR CIGS WILL DROP TONIGHT.


//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...NOON SUNDAY TO 10 PM
     MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743...NOON SUNDAY TO 4 AM
     TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 271146
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
646 AM CDT SUN JUL 27 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 12Z...

* TEMPORARY IFR/LIFR CIGS AT MAINLY ORD THROUGH 14Z.
* MVFR FOG AT BOTH AIRPORTS THROUGH 13Z-14Z.
* SCATTERED/AREA OF TSRA LATE THIS MORNING/EARLY THIS AFTERNOON WITH
  SCATTERED SHOWERS AFTERWARD.
* GUSTY WEST-NORTHWEST WINDS TODAY.
* NORTH-NORTHEAST WINDS MONDAY MORNING.
* POSSIBLE MVFR CIGS TONIGHT.



//DISCUSSION...UPDATED 12Z...

HIGH MOISTURE VALUES OVER THE AREA WILL SUPPORT FOG/LOW CLOUDS
THROUGH 13Z-14Z AND MAYBE EVEN TO 15Z ACROSS THE REGION. WOULD NOT
EXPECT CONDITIONS TO GET WORSE AT TAF SITES AFTER 12Z GIVEN
DAYBREAK AND AN INCREASING WIND FLOW.

A STRONG UPPER LEVEL LOW PRESSURE MOVING INTO NORTHWEST WI AS OF
12Z WILL ROTATE SOUTHEASTWARD OVER CHICAGO BY MID-AFTERNOON. JUST
AHEAD OF THIS WILL EXIST A FAIR AMOUNT OF LIFT AND UPPER
SUPPORT...WHICH OVERRIDING A COLD FRONT WITH INSTABILITY ALONG IT
WILL LIKELY SUPPORT THE DEVELOPMENT OF A LINE OF SHRA/TSRA. HOW
FAR SOUTH THIS WILL EXTEND IS UNCERTAIN BUT AT THIS TIME BELIEVE
ENOUGH THAT IT WARRANTS INCLUSION INTO THE TAF. AS THE HEART OF
THE UPPER LOW MOVES OVER THE AREA DURING THE MID TO LATE
AFTERNOON...WOULD EXPECT SCATTERED SHOWERS WITH POSSIBLY ISOLATED
STORMS.

BEHIND THE COLD FRONTAL PASSAGE LATE THIS MORNING/EARLY
AFTERNOON...THERE WILL BE A SHARP INCREASE IN THE WIND SPEEDS
FROM THE WEST-NORTHWEST. OCCASIONAL GUSTS IN EXCESS OF 25 KT ARE
PROBABLE. A SECONDARY COLD FRONT DROPPING SOUTHWARD LATE THIS
AFTERNOON WILL LIKELY KEEP SOME GUSTS INTO THE EVENING PERIOD DUE
TO ITS COOL AIR ADVECTION. THIS FRONT WILL ALSO LIKELY PROVIDE
SOME FOCUS FOR MVFR OR NEAR-MVFR CLOUDS THIS EVENING INTO EARLY
OVERNIGHT.


//ORD AND MDW CONFIDENCE...UPDATED 12Z...

* MEDIUM IN MVFR VISIBILITY DURATION AND LOW IN IFR CIG DURATION
  THIS MORNING.
* MEDIUM IN TSRA OCCURRING LATE THIS MORNING/EARLY THIS AFTERNOON.
  MEDIUM IN TIMING.
* HIGH IN WIND DIRECTION TODAY AND THIS EVENING...MEDIUM LATE
  TONIGHT AND MONDAY. MEDIUM IN SPEED.
* LOW IN HOW FAR CIGS WILL DROP TONIGHT.


//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...

MONDAY NIGHT...VFR.
TUESDAY...SLIGHT CHANCE OF AFTERNOON TSRA.
WEDNESDAY...SLIGHT CHANCE OF TSRA.
THURSDAY-SATURDAY...SLIGHT CHANCES OF TSRA. NORTHEAST WINDS.

MTF

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...NOON SUNDAY TO 10 PM
     MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743...NOON SUNDAY TO 4 AM
     TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 270906
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
406 AM CDT SUN JUL 27 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 09Z...

* MVFR FOG EARLY THIS MORNING WITH POSSIBLE TEMPORARY IFR FOG NEAR
  DAYBREAK.
* GUSTY WEST-NORTHWEST WINDS TODAY.
* SCATTERED SHRA LATE THIS MORNING AND AFTERNOON WITH POSSIBLE TSRA.
* CHANCE FOR TEMPORARY MVFR CIGS TONIGHT.

//DISCUSSION...UPDATED 06Z...

MOIST LOW-LEVEL AIR ASSOCIATED WITH A BROAD SURFACE TROUGH ACROSS
THE AREA EARLY THIS MORNING HAS ENABLED PATCHY TO AREAS OF FOG TO
DEVELOP AND WOULD EXPECT A SLOW EXPANSION IN THAT THROUGH
DAYBREAK. THERE ALREADY HAVE BEEN A FEW SITES IN THE REGION TO
REPORT IFR VISIBILITY SO CANNOT RULE THAT OUT AT TAF
SITES...NAMELY THE MORE FAVORED ONES SUCH AS DPA AND GYY. SOME
STRATUS ACROSS CENTRAL IL HAS UNDULATED IN COVERAGE BUT BELIEVE
MOST OF THAT WILL REMAIN SOUTH OF THE AREA WITH FOG BEING THE
PRIMARY RESTRICTION. FOG SHOULD DISSIPATE 1-2 HOURS AFTER SUNRISE
WITH THE AID OF INCREASING WESTERLY FLOW.

A STRONG UPPER LEVEL LOW OVER NORTHERN MN EARLY THIS MORNING WILL
ROTATE SOUTHEASTWARD OVER THE AREA THIS AFTERNOON. LIFT ASSOCIATED
WITH THIS WILL PASS OVER THE REGION AT A FAVORABLE TIME...LATE
MORNING AND AFTERNOON...TO SUPPORT AN UPTICK IN SHOWERS WITH
POSSIBLE ISOLATED THUNDER. HAVE INCLUDED MENTION OF THIS IN THE
TAFS...NAMELY THE CHICAGOLAND ONES AS RFD LOOKS TO BE A LITTLE
WEST OF THE BETTER FORCING. IN ADDITION...AT THE SURFACE A COLD
FRONT WILL TURN WINDS WEST-NORTHWEST AND STEEPENING LAPSE RATES
WILL SUPPORT GUSTY WINDS IN EXCESS OF 20 KT. A SECONDARY COLD
FRONT LATE TODAY WILL CONTINUE SOME GUSTINESS POSSIBLY THROUGH THE
EVENING.

//ORD AND MDW CONFIDENCE...UPDATED 09Z...

* HIGH IN MVFR FOG OCCURRING THROUGH 12Z. MEDIUM IN JUST HOW FAR
  VISIBILITY WILL FALL THROUGH THAT TIME.
* HIGH IN WIND DIRECTION AND MEDIUM IN WIND SPEEDS TODAY.
* MEDIUM IN SHRA AND TIMING. LOW IN ANY TSRA OCCURRING OVER THE
  TAF SITES BUT PROBABLE THERE WILL BE ISOLATED IN THE REGION THIS
  AFTERNOON.
* LOW IN MVFR CIGS TONIGHT.

//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

MTF/IZZI

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...NOON SUNDAY TO 10 PM
     MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743...NOON SUNDAY TO 4 AM
     TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 270906
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
406 AM CDT SUN JUL 27 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 09Z...

* MVFR FOG EARLY THIS MORNING WITH POSSIBLE TEMPORARY IFR FOG NEAR
  DAYBREAK.
* GUSTY WEST-NORTHWEST WINDS TODAY.
* SCATTERED SHRA LATE THIS MORNING AND AFTERNOON WITH POSSIBLE TSRA.
* CHANCE FOR TEMPORARY MVFR CIGS TONIGHT.

//DISCUSSION...UPDATED 06Z...

MOIST LOW-LEVEL AIR ASSOCIATED WITH A BROAD SURFACE TROUGH ACROSS
THE AREA EARLY THIS MORNING HAS ENABLED PATCHY TO AREAS OF FOG TO
DEVELOP AND WOULD EXPECT A SLOW EXPANSION IN THAT THROUGH
DAYBREAK. THERE ALREADY HAVE BEEN A FEW SITES IN THE REGION TO
REPORT IFR VISIBILITY SO CANNOT RULE THAT OUT AT TAF
SITES...NAMELY THE MORE FAVORED ONES SUCH AS DPA AND GYY. SOME
STRATUS ACROSS CENTRAL IL HAS UNDULATED IN COVERAGE BUT BELIEVE
MOST OF THAT WILL REMAIN SOUTH OF THE AREA WITH FOG BEING THE
PRIMARY RESTRICTION. FOG SHOULD DISSIPATE 1-2 HOURS AFTER SUNRISE
WITH THE AID OF INCREASING WESTERLY FLOW.

A STRONG UPPER LEVEL LOW OVER NORTHERN MN EARLY THIS MORNING WILL
ROTATE SOUTHEASTWARD OVER THE AREA THIS AFTERNOON. LIFT ASSOCIATED
WITH THIS WILL PASS OVER THE REGION AT A FAVORABLE TIME...LATE
MORNING AND AFTERNOON...TO SUPPORT AN UPTICK IN SHOWERS WITH
POSSIBLE ISOLATED THUNDER. HAVE INCLUDED MENTION OF THIS IN THE
TAFS...NAMELY THE CHICAGOLAND ONES AS RFD LOOKS TO BE A LITTLE
WEST OF THE BETTER FORCING. IN ADDITION...AT THE SURFACE A COLD
FRONT WILL TURN WINDS WEST-NORTHWEST AND STEEPENING LAPSE RATES
WILL SUPPORT GUSTY WINDS IN EXCESS OF 20 KT. A SECONDARY COLD
FRONT LATE TODAY WILL CONTINUE SOME GUSTINESS POSSIBLY THROUGH THE
EVENING.

//ORD AND MDW CONFIDENCE...UPDATED 09Z...

* HIGH IN MVFR FOG OCCURRING THROUGH 12Z. MEDIUM IN JUST HOW FAR
  VISIBILITY WILL FALL THROUGH THAT TIME.
* HIGH IN WIND DIRECTION AND MEDIUM IN WIND SPEEDS TODAY.
* MEDIUM IN SHRA AND TIMING. LOW IN ANY TSRA OCCURRING OVER THE
  TAF SITES BUT PROBABLE THERE WILL BE ISOLATED IN THE REGION THIS
  AFTERNOON.
* LOW IN MVFR CIGS TONIGHT.

//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

MTF/IZZI

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...NOON SUNDAY TO 10 PM
     MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743...NOON SUNDAY TO 4 AM
     TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 270822
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
322 AM CDT SUN JUL 27 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR FOG PROBABLE EARLY THIS MORNING WITH POSSIBLE TEMPORARY IFR
  FOG.
* GUSTY WEST-NORTHWEST WINDS TODAY.
* SCATTERED SHRA LATE THIS MORNING AND AFTERNOON WITH POSSIBLE TSRA.
* CHANCE FOR TEMPORARY MVFR CIGS SUNDAY NIGHT.

//DISCUSSION...UPDATED 06Z...

MOIST LOW-LEVEL AIR ASSOCIATED WITH A BROAD SURFACE TROUGH ACROSS
THE AREA EARLY THIS MORNING HAS ENABLED PATCHY TO AREAS OF FOG TO
DEVELOP AND WOULD EXPECT A SLOW EXPANSION IN THAT THROUGH
DAYBREAK. THERE ALREADY HAVE BEEN A FEW SITES IN THE REGION TO
REPORT IFR VISIBILITY SO CANNOT RULE THAT OUT AT TAF
SITES...NAMELY THE MORE FAVORED ONES SUCH AS DPA AND GYY. SOME
STRATUS ACROSS CENTRAL IL HAS UNDULATED IN COVERAGE BUT BELIEVE
MOST OF THAT WILL REMAIN SOUTH OF THE AREA WITH FOG BEING THE
PRIMARY RESTRICTION. FOG SHOULD DISSIPATE 1-2 HOURS AFTER SUNRISE
WITH THE AID OF INCREASING WESTERLY FLOW.

A STRONG UPPER LEVEL LOW OVER NORTHERN MN EARLY THIS MORNING WILL
ROTATE SOUTHEASTWARD OVER THE AREA THIS AFTERNOON. LIFT ASSOCIATED
WITH THIS WILL PASS OVER THE REGION AT A FAVORABLE TIME...LATE
MORNING AND AFTERNOON...TO SUPPORT AN UPTICK IN SHOWERS WITH
POSSIBLE ISOLATED THUNDER. HAVE INCLUDED MENTION OF THIS IN THE
TAFS...NAMELY THE CHICAGOLAND ONES AS RFD LOOKS TO BE A LITTLE
WEST OF THE BETTER FORCING. IN ADDITION...AT THE SURFACE A COLD
FRONT WILL TURN WINDS WEST-NORTHWEST AND STEEPENING LAPSE RATES
WILL SUPPORT GUSTY WINDS IN EXCESS OF 20 KT. A SECONDARY COLD
FRONT LATE TODAY WILL CONTINUE SOME GUSTINESS POSSIBLY THROUGH THE
EVENING.

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* MEDIUM IN MVFR FOG OCCURRING BETWEEN 09Z AND 13Z. LOW IN JUST
  HOW FAR VISIBILITY WILL FALL.
* HIGH IN WIND DIRECTION AND MEDIUM IN WIND SPEEDS TODAY.
* MEDIUM IN SHRA AND TIMING. LOW IN ANY TSRA OCCURRING OVER THE
  TAF SITES BUT PROBABLE THERE WILL BE ISOLATED IN THE REGION THIS
  AFTERNOON.
* LOW IN MVFR CIGS SUNDAY NIGHT.

//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

MTF/IZZI

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...NOON SUNDAY TO 10 PM
     MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743...NOON SUNDAY TO 4 AM
     TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO










000
FXUS63 KLOT 270822
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
322 AM CDT SUN JUL 27 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...ONE MORE DAY OF A DIFFICULT AND MESSY PATTERN THAT WILL
RESULT IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION.  NO SEVERE
STORMS ARE EXPECTED.  TEMPERATURES FALL THIS AFTERNOON AND REMAIN
BELOW NORMAL THROUGH THE REST OF THE WEEK. WE DRY OUT MONDAY AND
THEN HAVE LOW CHANCES OF PRECIP TUESDAY THROUGH SATURDAY.

TODAY AND TONIGHT...
AN UPPER LEVEL LOW IS OVER NORTHERN MINNESOTA WHILE A LARGER LOW IS
OVER NORTHERN QUEBEC. A SHORTWAVE TROUGH IS ALSO OVER EASTERN IOWA
WITH CONVECTION OVER CENTRAL WI.  SPOTTY SHOWERS/SPRINKLES HAVE
SPROUTED OVER SOUTHEAST WI AND NOT EXPECTING MUCH ACTIVITY FROM
THOSE SPRINKLES.  ADDITIONAL MORE IMPRESSIVE CONVECTION HAS FIRED
ALONG A WEAK BOUNDARY OVER CENTRAL IL. MAY SEE A FEW STORMS SOUTH OF
A PERU TO RENSSELAER LINE EARLY THIS MORNING.

FOG IS PRESENT OVER MUCH OF THE FORECAST AREA THIS MORNING AS
WELL. CLOUD COVER IS EXPANDING FROM SOUTH TO NORTH AND VSBY
INCREASES AS THE CLOUDS MOVE OVERHEAD. AS SUCH WILL HOLD OFF ON A
DENSE FOG ADVISORY FOR NOW AND SEE HOW THE CLOUD COVER SPREADS
ACROSS THE REGION.

EXPECTING ADDITIONAL CONVECTION TO FIRE AHEAD OF THE SHORTWAVE THIS
MORNING AND MOVE INTO NORTH CENTRAL IL. INSTABILITY MAY BE
LIMITED...BUT SOME THUNDER SHOULD BE REALIZED BASED ON
OBSERVATIONAL TRENDS UPSTREAM. THE SHOWERS AND STORMS WILL PUSH
EAST INTO THE AFTERNOON AS THE SHORTWAVE MOVES THROUGH. A COLD
FRONT CURRENTLY ACROSS NW WI THROUGH CENTRAL IA WILL ALSO
TRANSVERSE THE REGION AHEAD OF THE UPPER LEVEL LOW. THE LOW WILL
SWING OVER THE LAKE THIS AFTERNOON AND EXPECTING ADDITIONAL
ISOLATED TO SCATTERED STORMS WITH THIS FEATURE. TODAY WILL NOT BE
A WASH OUT HOWEVER AND THERE SHOULD BE PLENTY OF DRY HOURS.
ISOLATED SHOWERS CONTINUE INTO THE EVENING AND THEN THE BACK SIDE
OF THE UPPER LEVEL TROUGH SLIDES SOUTH THROUGH THE REGION
OVERNIGHT CLEARING OUT THE CLOUDS.

GUSTY WINDS ARE EXPECTED...AT TIMES TO 30 MPH THIS AFTERNOON.
WITH THE STRONG WINDS OVER LAKE MICHIGAN ORIENTED PARALLEL TO THE
FETCH...WAVES WILL BUILD CONSIDERABLY TONIGHT AND PERSIST INTO
MONDAY...AND A BEACH HAZARDS STATEMENT WILL GO INTO EFFECT FOR ALL
LAKE ADJACENT COUNTIES IN THE FORECAST AREA.

CLOUD COVER SHOULD STAY WITH US MOST OF THE DAY LIMITING HOW WARM WE
GET AGAIN.  HIGHS WILL VARY FROM AROUND 80 NORTH TO THE MID 80S
SOUTH WHERE THERE COULD BE MORE SUNSHINE. TEMPS AND DEWPOINTS WILL
FALL THIS AFTERNOON THOUGH AS COOLER AIR MOVES IN BEHIND THE COLD
FRONT.

MONDAY...
THE UPPER LEVEL LOW WEAKENS TO AN OPEN TROUGH AND THEN MERGES WITH
THE STRONGER LOW OVER QUEBEC MONDAY NIGHT.  WE STAY STUCK IN AN
UPPER LEVEL PATTERN WITH A RIDGE TO THE WEST AND TROUGH TO THE
EAST. THE SURFACE LOW MOVES OVER NEW ENGLAND MONDAY MORNING AND
HIGH PRESSURE BUILDS OVER THE PLAINS. MONDAY LOOKS DRY WITH WEAK
VORTICITY STREAMERS PASSING BY OVERHEAD. HIGHS WILL BE WELL BELOW
NORMAL IN THE LOW TO MID 70S. ONSHORE FLOW WILL KEEP THE LAKEFRONT
NEAR 70. THEN A BEAUTIFUL NIGHT FOR SLEEPING IS IN STORE WITH LOWS
IN THE MID 50S...EXCEPT FOR AROUND 60 DOWNTOWN.

TUESDAY THROUGH SATURDAY...
WE REMAIN IN THE STAGNANT UPPER LEVEL PATTERN WITH A SURFACE HIGH
OVER THE PLAINS.  KEPT PERIODIC LOW CHANCES OF SHOWERS AND STORMS IN
THE EXTENDED FORECAST AS VORTICITY STREAMERS CONTINUE TO ROTATE
THROUGH THE REGION. MOISTURE IS NOT PLENTIFUL SO NOT EXPECTING MUCH
PRECIP AT THIS TIME.  TEMPERATURES ALSO REMAIN BELOW NORMAL IN THE
70S WITH A FEW SITES MAYBE REACHING 80.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR FOG PROBABLE EARLY THIS MORNING WITH POSSIBLE TEMPORARY IFR
  FOG.
* GUSTY WEST-NORTHWEST WINDS TODAY.
* SCATTERED SHRA LATE THIS MORNING AND AFTERNOON WITH POSSIBLE TSRA.
* CHANCE FOR TEMPORARY MVFR CIGS SUNDAY NIGHT.

//DISCUSSION...UPDATED 06Z...

MOIST LOW-LEVEL AIR ASSOCIATED WITH A BROAD SURFACE TROUGH ACROSS
THE AREA EARLY THIS MORNING HAS ENABLED PATCHY TO AREAS OF FOG TO
DEVELOP AND WOULD EXPECT A SLOW EXPANSION IN THAT THROUGH
DAYBREAK. THERE ALREADY HAVE BEEN A FEW SITES IN THE REGION TO
REPORT IFR VISIBILITY SO CANNOT RULE THAT OUT AT TAF
SITES...NAMELY THE MORE FAVORED ONES SUCH AS DPA AND GYY. SOME
STRATUS ACROSS CENTRAL IL HAS UNDULATED IN COVERAGE BUT BELIEVE
MOST OF THAT WILL REMAIN SOUTH OF THE AREA WITH FOG BEING THE
PRIMARY RESTRICTION. FOG SHOULD DISSIPATE 1-2 HOURS AFTER SUNRISE
WITH THE AID OF INCREASING WESTERLY FLOW.

A STRONG UPPER LEVEL LOW OVER NORTHERN MN EARLY THIS MORNING WILL
ROTATE SOUTHEASTWARD OVER THE AREA THIS AFTERNOON. LIFT ASSOCIATED
WITH THIS WILL PASS OVER THE REGION AT A FAVORABLE TIME...LATE
MORNING AND AFTERNOON...TO SUPPORT AN UPTICK IN SHOWERS WITH
POSSIBLE ISOLATED THUNDER. HAVE INCLUDED MENTION OF THIS IN THE
TAFS...NAMELY THE CHICAGOLAND ONES AS RFD LOOKS TO BE A LITTLE
WEST OF THE BETTER FORCING. IN ADDITION...AT THE SURFACE A COLD
FRONT WILL TURN WINDS WEST-NORTHWEST AND STEEPENING LAPSE RATES
WILL SUPPORT GUSTY WINDS IN EXCESS OF 20 KT. A SECONDARY COLD
FRONT LATE TODAY WILL CONTINUE SOME GUSTINESS POSSIBLY THROUGH THE
EVENING.

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* MEDIUM IN MVFR FOG OCCURRING BETWEEN 09Z AND 13Z. LOW IN JUST
  HOW FAR VISIBILITY WILL FALL.
* HIGH IN WIND DIRECTION AND MEDIUM IN WIND SPEEDS TODAY.
* MEDIUM IN SHRA AND TIMING. LOW IN ANY TSRA OCCURRING OVER THE
  TAF SITES BUT PROBABLE THERE WILL BE ISOLATED IN THE REGION THIS
  AFTERNOON.
* LOW IN MVFR CIGS SUNDAY NIGHT.

//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

MTF/IZZI

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...NOON SUNDAY TO 10 PM
     MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743...NOON SUNDAY TO 4 AM
     TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO











000
FXUS63 KLOT 270803
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
303 AM CDT SUN JUL 27 2014

.DISCUSSION...
736 PM CDT

OVERALL THREAT OF SEVERE WEATHER HAS DIMINISHED IN THE NEAR TERM
AND FOR THE REMAINDER OF THE EVENING...WITH CHANCES APPEARING LOW
FOR ADDITIONAL THUNDERSTORM DEVELOPMENT OVERNIGHT.

LATEST RADAR IMAGERY DEPICTING REMAINING SHOWERY ACTIVITY EXITING
THE SOUTHEAST CWA AS COMPLEX OVER CENTRAL ILLINOIS AND INDIANA
CONTINUES TO PROGRESS TO THE EAST...LEAVING THE CWA AND MUCH OF
THE REGION TO THE NORTH AND NORTHWEST DRY AT THIS TIME. LACK OF
ANY REAL GOOD FOCUS THIS EVENING AND A STRONG CAP STILL IN PLACE
OVER LINGERING STATIONARY BOUNDARY WILL LIMIT FURTHER
STRONG/SEVERE THUNDERSTORM DEVELOPMENT FOR THE REST OF THE
EVENING. DID ADJUST POPS TO KEEP LOW CHANCE/SLIGHT CHANCE POPS FOR
SHOWERS AND THUNDERSTORMS MAINLY FOR THE SOUTHERN CWA WITH THIS
LINGERING BOUNDARY STILL IN PLACE...BUT WITH ANY FURTHER
DEVELOPMENT MORE THAN LIKELY REMAINING MORE SHOWERY. ALSO GOING TO
ADD A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE
NORTHERN CWA VERY LATE TONIGHT INTO EARLY SUNDAY MORNING. LARGE
VORT MAX ENTERING THE FAR NORTHERN PLAINS WILL SINK SOUTHEAST
THROUGH THE UPPER MIDWEST THROUGH SUNDAY MORNING. VORT LOBE OUT
AHEAD OF IT WILL SWING SOUTHEAST TO EASTERN IOWA AND SOUTHWEST
WISCONSIN AND COULD HELP THUNDERSTORM DEVELOPMENT IN THESE
AREAS...ESPECIALLY ALONG COLD FRONTAL BOUNDARY. CONFIDENCE OF
COVERAGE AND INTENSITY IS LOW AT THIS TIME BUT THERE IS A
POSSIBILITY FOR SOME OF THIS DEVELOPMENT TO REACH FAR NORTHERN
ILLINOIS BY VERY LATE TONIGHT AND EARLY SUNDAY MORNING. IF THIS
WERE TO OCCUR...WOULD EXPECT THAT HEAVY DOWNPOURS WOULD BE THE
MAIN THREAT.

VERY MOIST CONDITIONS IN A RELAXED SURFACE PATTERN WILL BE
CONDUCIVE FOR FOG DEVELOPMENT TONIGHT ESPECIALLY AS WINDS FURTHER
DIMINISH...AND SO HAVE ADDED MENTION OF FOG FOR THE ENTIRE CWA
TONIGHT.

RODRIGUEZ

//PREV DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR FOG PROBABLE EARLY THIS MORNING WITH POSSIBLE TEMPORARY IFR
  FOG.
* GUSTY WEST-NORTHWEST WINDS TODAY.
* SCATTERED SHRA LATE THIS MORNING AND AFTERNOON WITH POSSIBLE TSRA.
* CHANCE FOR TEMPORARY MVFR CIGS SUNDAY NIGHT.

//DISCUSSION...UPDATED 06Z...

MOIST LOW-LEVEL AIR ASSOCIATED WITH A BROAD SURFACE TROUGH ACROSS
THE AREA EARLY THIS MORNING HAS ENABLED PATCHY TO AREAS OF FOG TO
DEVELOP AND WOULD EXPECT A SLOW EXPANSION IN THAT THROUGH
DAYBREAK. THERE ALREADY HAVE BEEN A FEW SITES IN THE REGION TO
REPORT IFR VISIBILITY SO CANNOT RULE THAT OUT AT TAF
SITES...NAMELY THE MORE FAVORED ONES SUCH AS DPA AND GYY. SOME
STRATUS ACROSS CENTRAL IL HAS UNDULATED IN COVERAGE BUT BELIEVE
MOST OF THAT WILL REMAIN SOUTH OF THE AREA WITH FOG BEING THE
PRIMARY RESTRICTION. FOG SHOULD DISSIPATE 1-2 HOURS AFTER SUNRISE
WITH THE AID OF INCREASING WESTERLY FLOW.

A STRONG UPPER LEVEL LOW OVER NORTHERN MN EARLY THIS MORNING WILL
ROTATE SOUTHEASTWARD OVER THE AREA THIS AFTERNOON. LIFT ASSOCIATED
WITH THIS WILL PASS OVER THE REGION AT A FAVORABLE TIME...LATE
MORNING AND AFTERNOON...TO SUPPORT AN UPTICK IN SHOWERS WITH
POSSIBLE ISOLATED THUNDER. HAVE INCLUDED MENTION OF THIS IN THE
TAFS...NAMELY THE CHICAGOLAND ONES AS RFD LOOKS TO BE A LITTLE
WEST OF THE BETTER FORCING. IN ADDITION...AT THE SURFACE A COLD
FRONT WILL TURN WINDS WEST-NORTHWEST AND STEEPENING LAPSE RATES
WILL SUPPORT GUSTY WINDS IN EXCESS OF 20 KT. A SECONDARY COLD
FRONT LATE TODAY WILL CONTINUE SOME GUSTINESS POSSIBLY THROUGH THE
EVENING.

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* MEDIUM IN MVFR FOG OCCURRING BETWEEN 09Z AND 13Z. LOW IN JUST
  HOW FAR VISIBILITY WILL FALL.
* HIGH IN WIND DIRECTION AND MEDIUM IN WIND SPEEDS TODAY.
* MEDIUM IN SHRA AND TIMING. LOW IN ANY TSRA OCCURRING OVER THE
  TAF SITES BUT PROBABLE THERE WILL BE ISOLATED IN THE REGION THIS
  AFTERNOON.
* LOW IN MVFR CIGS SUNDAY NIGHT.

//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

MTF/IZZI

&&

.MARINE...
300 AM CDT

AN ACTIVE AND ATYPICAL SUMMERTIME PATTERN WILL UNFOLD ACROSS THE
LAKE THIS AFTERNOON THROUGH MONDAY NIGHT. LOW PRESSURE OVER THE
MIDDLE OF LAKE MICHIGAN BY MID TO LATE MORNING WILL MOVE EASTWARD
AND SLOWLY DEEPEN THIS AFTERNOON INTO TONIGHT. AS THIS OCCURS...COOL
AIR ADVECTION ON ITS BACKSIDE WITHIN A TIGHTENING PRESSURE
GRADIENT WILL DRIVE STRONG NORTHERLY WINDS. THESE WINDS LOOK TO
COME UP QUICKLY LATE THIS AFTERNOON AND BE MAXIMIZED THIS EVENING
INTO EARLY OVERNIGHT AND IT IS THEN WHEN OCCASIONAL GALE FORCE
GUSTS COULD OCCUR...ESPECIALLY OVER THE CENTRAL AND SOUTHERN PART
OF THE LAKE AND INTO THE INDIANA NEARSHORE. WINDS WILL BE SLOW TO
DIMINISH DURING MONDAY BUT THEN QUICKLY DROP MONDAY NIGHT. GIVEN
THE LONG FETCH THAT WILL BE REALIZED WAVES WILL BE ON THE UPPER
END OF THE SPECTRUM FOR SUMMERTIME WITH 7 TO 10 AND OCCASIONAL
HIGHER WAVES IN THE CENTRAL AND SOUTHERN PART OF THE LAKE INTO THE
INDIANA AND POSSIBLY ILLINOIS NEARSHORE AREAS. STRONG CANADIAN
HIGH PRESSURE FOR MID-SUMMER OVER THE NORTHERN PLAINS ON MONDAY
WILL EVOLVE EASTWARD OVER LAKE MICHIGAN BY MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014...10 PM SUNDAY TO 4 AM TUESDAY.

     BEACH HAZARDS STATEMENT...ILZ006...10 PM SUNDAY TO 10 PM MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...6 PM SUNDAY TO 4 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...NOON SUNDAY TO 10 PM
     MONDAY.

     SMALL CRAFT ADVISORY...LMZ742-LMZ743...NOON SUNDAY TO 4 AM
     TUESDAY.

     SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 PM SUNDAY TO 4 AM
     TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 270542
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1242 AM CDT SUN JUL 27 2014

.DISCUSSION...
736 PM CDT

OVERALL THREAT OF SEVERE WEATHER HAS DIMINISHED IN THE NEAR TERM
AND FOR THE REMAINDER OF THE EVENING...WITH CHANCES APPEARING LOW
FOR ADDITIONAL THUNDERSTORM DEVELOPMENT OVERNIGHT.

LATEST RADAR IMAGERY DEPICTING REMAINING SHOWERY ACTIVITY EXITING
THE SOUTHEAST CWA AS COMPLEX OVER CENTRAL ILLINOIS AND INDIANA
CONTINUES TO PROGRESS TO THE EAST...LEAVING THE CWA AND MUCH OF
THE REGION TO THE NORTH AND NORTHWEST DRY AT THIS TIME. LACK OF
ANY REAL GOOD FOCUS THIS EVENING AND A STRONG CAP STILL IN PLACE
OVER LINGERING STATIONARY BOUNDARY WILL LIMIT FURTHER
STRONG/SEVERE THUNDERSTORM DEVELOPMENT FOR THE REST OF THE
EVENING. DID ADJUST POPS TO KEEP LOW CHANCE/SLIGHT CHANCE POPS FOR
SHOWERS AND THUNDERSTORMS MAINLY FOR THE SOUTHERN CWA WITH THIS
LINGERING BOUNDARY STILL IN PLACE...BUT WITH ANY FURTHER
DEVELOPMENT MORE THAN LIKELY REMAINING MORE SHOWERY. ALSO GOING TO
ADD A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE
NORTHERN CWA VERY LATE TONIGHT INTO EARLY SUNDAY MORNING. LARGE
VORT MAX ENTERING THE FAR NORTHERN PLAINS WILL SINK SOUTHEAST
THROUGH THE UPPER MIDWEST THROUGH SUNDAY MORNING. VORT LOBE OUT
AHEAD OF IT WILL SWING SOUTHEAST TO EASTERN IOWA AND SOUTHWEST
WISCONSIN AND COULD HELP THUNDERSTORM DEVELOPMENT IN THESE
AREAS...ESPECIALLY ALONG COLD FRONTAL BOUNDARY. CONFIDENCE OF
COVERAGE AND INTENSITY IS LOW AT THIS TIME BUT THERE IS A
POSSIBILITY FOR SOME OF THIS DEVELOPMENT TO REACH FAR NORTHERN
ILLINOIS BY VERY LATE TONIGHT AND EARLY SUNDAY MORNING. IF THIS
WERE TO OCCUR...WOULD EXPECT THAT HEAVY DOWNPOURS WOULD BE THE
MAIN THREAT.

VERY MOIST CONDITIONS IN A RELAXED SURFACE PATTERN WILL BE
CONDUCIVE FOR FOG DEVELOPMENT TONIGHT ESPECIALLY AS WINDS FURTHER
DIMINISH...AND SO HAVE ADDED MENTION OF FOG FOR THE ENTIRE CWA
TONIGHT.

RODRIGUEZ

//PREV DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR FOG PROBABLE EARLY THIS MORNING WITH POSSIBLE TEMPORARY IFR
  FOG.
* GUSTY WEST-NORTHWEST WINDS TODAY.
* SCATTERED SHRA LATE THIS MORNING AND AFTERNOON WITH POSSIBLE TSRA.
* CHANCE FOR TEMPORARY MVFR CIGS SUNDAY NIGHT.


//DISCUSSION...UPDATED 06Z...

MOIST LOW-LEVEL AIR ASSOCIATED WITH A BROAD SURFACE TROUGH ACROSS
THE AREA EARLY THIS MORNING HAS ENABLED PATCHY TO AREAS OF FOG TO
DEVELOP AND WOULD EXPECT A SLOW EXPANSION IN THAT THROUGH
DAYBREAK. THERE ALREADY HAVE BEEN A FEW SITES IN THE REGION TO
REPORT IFR VISIBILITY SO CANNOT RULE THAT OUT AT TAF
SITES...NAMELY THE MORE FAVORED ONES SUCH AS DPA AND GYY. SOME
STRATUS ACROSS CENTRAL IL HAS UNDULATED IN COVERAGE BUT BELIEVE
MOST OF THAT WILL REMAIN SOUTH OF THE AREA WITH FOG BEING THE
PRIMARY RESTRICTION. FOG SHOULD DISSIPATE 1-2 HOURS AFTER SUNRISE
WITH THE AID OF INCREASING WESTERLY FLOW.

A STRONG UPPER LEVEL LOW OVER NORTHERN MN EARLY THIS MORNING WILL
ROTATE SOUTHEASTWARD OVER THE AREA THIS AFTERNOON. LIFT ASSOCIATED
WITH THIS WILL PASS OVER THE REGION AT A FAVORABLE TIME...LATE
MORNING AND AFTERNOON...TO SUPPORT AN UPTICK IN SHOWERS WITH
POSSIBLE ISOLATED THUNDER. HAVE INCLUDED MENTION OF THIS IN THE
TAFS...NAMELY THE CHICAGOLAND ONES AS RFD LOOKS TO BE A LITTLE
WEST OF THE BETTER FORCING. IN ADDITION...AT THE SURFACE A COLD
FRONT WILL TURN WINDS WEST-NORTHWEST AND STEEPENING LAPSE RATES
WILL SUPPORT GUSTY WINDS IN EXCESS OF 20 KT. A SECONDARY COLD
FRONT LATE TODAY WILL CONTINUE SOME GUSTINESS POSSIBLY THROUGH THE
EVENING.


//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* MEDIUM IN MVFR FOG OCCURRING BETWEEN 09Z AND 13Z. LOW IN JUST
  HOW FAR VISIBILITY WILL FALL.
* HIGH IN WIND DIRECTION AND MEDIUM IN WIND SPEEDS TODAY.
* MEDIUM IN SHRA AND TIMING. LOW IN ANY TSRA OCCURRING OVER THE
  TAF SITES BUT PROBABLE THERE WILL BE ISOLATED IN THE REGION THIS
  AFTERNOON.
* LOW IN MVFR CIGS SUNDAY NIGHT.


//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

MTF/IZZI

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 270542
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1242 AM CDT SUN JUL 27 2014

.DISCUSSION...
736 PM CDT

OVERALL THREAT OF SEVERE WEATHER HAS DIMINISHED IN THE NEAR TERM
AND FOR THE REMAINDER OF THE EVENING...WITH CHANCES APPEARING LOW
FOR ADDITIONAL THUNDERSTORM DEVELOPMENT OVERNIGHT.

LATEST RADAR IMAGERY DEPICTING REMAINING SHOWERY ACTIVITY EXITING
THE SOUTHEAST CWA AS COMPLEX OVER CENTRAL ILLINOIS AND INDIANA
CONTINUES TO PROGRESS TO THE EAST...LEAVING THE CWA AND MUCH OF
THE REGION TO THE NORTH AND NORTHWEST DRY AT THIS TIME. LACK OF
ANY REAL GOOD FOCUS THIS EVENING AND A STRONG CAP STILL IN PLACE
OVER LINGERING STATIONARY BOUNDARY WILL LIMIT FURTHER
STRONG/SEVERE THUNDERSTORM DEVELOPMENT FOR THE REST OF THE
EVENING. DID ADJUST POPS TO KEEP LOW CHANCE/SLIGHT CHANCE POPS FOR
SHOWERS AND THUNDERSTORMS MAINLY FOR THE SOUTHERN CWA WITH THIS
LINGERING BOUNDARY STILL IN PLACE...BUT WITH ANY FURTHER
DEVELOPMENT MORE THAN LIKELY REMAINING MORE SHOWERY. ALSO GOING TO
ADD A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE
NORTHERN CWA VERY LATE TONIGHT INTO EARLY SUNDAY MORNING. LARGE
VORT MAX ENTERING THE FAR NORTHERN PLAINS WILL SINK SOUTHEAST
THROUGH THE UPPER MIDWEST THROUGH SUNDAY MORNING. VORT LOBE OUT
AHEAD OF IT WILL SWING SOUTHEAST TO EASTERN IOWA AND SOUTHWEST
WISCONSIN AND COULD HELP THUNDERSTORM DEVELOPMENT IN THESE
AREAS...ESPECIALLY ALONG COLD FRONTAL BOUNDARY. CONFIDENCE OF
COVERAGE AND INTENSITY IS LOW AT THIS TIME BUT THERE IS A
POSSIBILITY FOR SOME OF THIS DEVELOPMENT TO REACH FAR NORTHERN
ILLINOIS BY VERY LATE TONIGHT AND EARLY SUNDAY MORNING. IF THIS
WERE TO OCCUR...WOULD EXPECT THAT HEAVY DOWNPOURS WOULD BE THE
MAIN THREAT.

VERY MOIST CONDITIONS IN A RELAXED SURFACE PATTERN WILL BE
CONDUCIVE FOR FOG DEVELOPMENT TONIGHT ESPECIALLY AS WINDS FURTHER
DIMINISH...AND SO HAVE ADDED MENTION OF FOG FOR THE ENTIRE CWA
TONIGHT.

RODRIGUEZ

//PREV DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR FOG PROBABLE EARLY THIS MORNING WITH POSSIBLE TEMPORARY IFR
  FOG.
* GUSTY WEST-NORTHWEST WINDS TODAY.
* SCATTERED SHRA LATE THIS MORNING AND AFTERNOON WITH POSSIBLE TSRA.
* CHANCE FOR TEMPORARY MVFR CIGS SUNDAY NIGHT.


//DISCUSSION...UPDATED 06Z...

MOIST LOW-LEVEL AIR ASSOCIATED WITH A BROAD SURFACE TROUGH ACROSS
THE AREA EARLY THIS MORNING HAS ENABLED PATCHY TO AREAS OF FOG TO
DEVELOP AND WOULD EXPECT A SLOW EXPANSION IN THAT THROUGH
DAYBREAK. THERE ALREADY HAVE BEEN A FEW SITES IN THE REGION TO
REPORT IFR VISIBILITY SO CANNOT RULE THAT OUT AT TAF
SITES...NAMELY THE MORE FAVORED ONES SUCH AS DPA AND GYY. SOME
STRATUS ACROSS CENTRAL IL HAS UNDULATED IN COVERAGE BUT BELIEVE
MOST OF THAT WILL REMAIN SOUTH OF THE AREA WITH FOG BEING THE
PRIMARY RESTRICTION. FOG SHOULD DISSIPATE 1-2 HOURS AFTER SUNRISE
WITH THE AID OF INCREASING WESTERLY FLOW.

A STRONG UPPER LEVEL LOW OVER NORTHERN MN EARLY THIS MORNING WILL
ROTATE SOUTHEASTWARD OVER THE AREA THIS AFTERNOON. LIFT ASSOCIATED
WITH THIS WILL PASS OVER THE REGION AT A FAVORABLE TIME...LATE
MORNING AND AFTERNOON...TO SUPPORT AN UPTICK IN SHOWERS WITH
POSSIBLE ISOLATED THUNDER. HAVE INCLUDED MENTION OF THIS IN THE
TAFS...NAMELY THE CHICAGOLAND ONES AS RFD LOOKS TO BE A LITTLE
WEST OF THE BETTER FORCING. IN ADDITION...AT THE SURFACE A COLD
FRONT WILL TURN WINDS WEST-NORTHWEST AND STEEPENING LAPSE RATES
WILL SUPPORT GUSTY WINDS IN EXCESS OF 20 KT. A SECONDARY COLD
FRONT LATE TODAY WILL CONTINUE SOME GUSTINESS POSSIBLY THROUGH THE
EVENING.


//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* MEDIUM IN MVFR FOG OCCURRING BETWEEN 09Z AND 13Z. LOW IN JUST
  HOW FAR VISIBILITY WILL FALL.
* HIGH IN WIND DIRECTION AND MEDIUM IN WIND SPEEDS TODAY.
* MEDIUM IN SHRA AND TIMING. LOW IN ANY TSRA OCCURRING OVER THE
  TAF SITES BUT PROBABLE THERE WILL BE ISOLATED IN THE REGION THIS
  AFTERNOON.
* LOW IN MVFR CIGS SUNDAY NIGHT.


//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

MTF/IZZI

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 270313
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1013 PM CDT SAT JUL 26 2014

.DISCUSSION...
736 PM CDT

OVERALL THREAT OF SEVERE WEATHER HAS DIMINISHED IN THE NEAR TERM
AND FOR THE REMAINDER OF THE EVENING...WITH CHANCES APPEARING LOW
FOR ADDITIONAL THUNDERSTORM DEVELOPMENT OVERNIGHT.

LATEST RADAR IMAGERY DEPICTING REMAINING SHOWERY ACTIVITY EXITING
THE SOUTHEAST CWA AS COMPLEX OVER CENTRAL ILLINOIS AND INDIANA
CONTINUES TO PROGRESS TO THE EAST...LEAVING THE CWA AND MUCH OF
THE REGION TO THE NORTH AND NORTHWEST DRY AT THIS TIME. LACK OF
ANY REAL GOOD FOCUS THIS EVENING AND A STRONG CAP STILL IN PLACE
OVER LINGERING STATIONARY BOUNDARY WILL LIMIT FURTHER
STRONG/SEVERE THUNDERSTORM DEVELOPMENT FOR THE REST OF THE
EVENING. DID ADJUST POPS TO KEEP LOW CHANCE/SLIGHT CHANCE POPS FOR
SHOWERS AND THUNDERSTORMS MAINLY FOR THE SOUTHERN CWA WITH THIS
LINGERING BOUNDARY STILL IN PLACE...BUT WITH ANY FURTHER
DEVELOPMENT MORE THAN LIKELY REMAINING MORE SHOWERY. ALSO GOING TO
ADD A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE
NORTHERN CWA VERY LATE TONIGHT INTO EARLY SUNDAY MORNING. LARGE
VORT MAX ENTERING THE FAR NORTHERN PLAINS WILL SINK SOUTHEAST
THROUGH THE UPPER MIDWEST THROUGH SUNDAY MORNING. VORT LOBE OUT
AHEAD OF IT WILL SWING SOUTHEAST TO EASTERN IOWA AND SOUTHWEST
WISCONSIN AND COULD HELP THUNDERSTORM DEVELOPMENT IN THESE
AREAS...ESPECIALLY ALONG COLD FRONTAL BOUNDARY. CONFIDENCE OF
COVERAGE AND INTENSITY IS LOW AT THIS TIME BUT THERE IS A
POSSIBILITY FOR SOME OF THIS DEVELOPMENT TO REACH FAR NORTHERN
ILLINOIS BY VERY LATE TONIGHT AND EARLY SUNDAY MORNING. IF THIS
WERE TO OCCUR...WOULD EXPECT THAT HEAVY DOWNPOURS WOULD BE THE
MAIN THREAT.

VERY MOIST CONDITIONS IN A RELAXED SURFACE PATTERN WILL BE
CONDUCIVE FOR FOG DEVELOPMENT TONIGHT ESPECIALLY AS WINDS FURTHER
DIMINISH...AND SO HAVE ADDED MENTION OF FOG FOR THE ENTIRE CWA
TONIGHT.

RODRIGUEZ

//PREV DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 03Z...

* SOME FOG POSSIBLE OVERNIGHT...MVFR VSBY PROBABLE WITH A CHANCE
  OF IFR VSBY
* GUSTY WNW WINDS DEVELOP SUNDAY AFTERNOON
* SLIGHT CHANCE OF ISOLD SHRA OR TSRA SUNDAY

IZZI

//DISCUSSION...UPDATED 00Z...

DIMINISHING WINDS...CLEARING SKIES...AND VERY MOIST AIR MASS
FILTERING INTO THE AREA WILL SET THE STAGE FOR GROUND FOG TO
DEVELOP TONIGHT. THE MOST DENSE FOG SHOULD BE IN OUTLYING AREAS
BUT IFR CONDITIONS OR LOWER ARE A POSSIBILITY EVEN IN THE URBAN
AREAS. STRONG UPPER TROUGH WILL DIG SOUTHEAST INTO THE GREAT LAKES
REGION SUNDAY MORNING WITH INCREASING WINDS AFTER SUNRISE QUICKLY
MIXING OUT ANY FOG/VSBY EARLY SUNDAY MORNING. WINDS WILL REALLY
RAMP UP BY LATE MORNING/EARLY AFTERNOON SUNDAY AS BEHIND COLD
FRONT MOVING THROUGH THE AREA...GUSTS OF 25-30KT LOOK LIKE A GOOD
BET DURING THE AFTERNOON. NOT OUT OF THE QUESTION THAT THERE
COULD BE ISOLD SHRA OR EVENING TSRA AROUND SUNDAY...BUT EVEN IF
ANY FORM COVERAGE SHOULD BE LOW AND DURATION BRIEF IN ANY GIVEN
LOCATION SO NO REASON TO INCLUDE IN TERMINAL FORECAST AT THIS
TIME.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 03Z...

* MEDIUM-HIGH CONFIDENCE IN VSBY RESTRICTIONS DEVELOPING DUE TO
  FOG OVERNIGHT BUT LOW CONFIDENCE IN HOW LOW VSBYS DROP
* HIGH CONFIDENCE IN OTHER FORECAST ELEMENTS

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

IZZI

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 270313
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1013 PM CDT SAT JUL 26 2014

.DISCUSSION...
736 PM CDT

OVERALL THREAT OF SEVERE WEATHER HAS DIMINISHED IN THE NEAR TERM
AND FOR THE REMAINDER OF THE EVENING...WITH CHANCES APPEARING LOW
FOR ADDITIONAL THUNDERSTORM DEVELOPMENT OVERNIGHT.

LATEST RADAR IMAGERY DEPICTING REMAINING SHOWERY ACTIVITY EXITING
THE SOUTHEAST CWA AS COMPLEX OVER CENTRAL ILLINOIS AND INDIANA
CONTINUES TO PROGRESS TO THE EAST...LEAVING THE CWA AND MUCH OF
THE REGION TO THE NORTH AND NORTHWEST DRY AT THIS TIME. LACK OF
ANY REAL GOOD FOCUS THIS EVENING AND A STRONG CAP STILL IN PLACE
OVER LINGERING STATIONARY BOUNDARY WILL LIMIT FURTHER
STRONG/SEVERE THUNDERSTORM DEVELOPMENT FOR THE REST OF THE
EVENING. DID ADJUST POPS TO KEEP LOW CHANCE/SLIGHT CHANCE POPS FOR
SHOWERS AND THUNDERSTORMS MAINLY FOR THE SOUTHERN CWA WITH THIS
LINGERING BOUNDARY STILL IN PLACE...BUT WITH ANY FURTHER
DEVELOPMENT MORE THAN LIKELY REMAINING MORE SHOWERY. ALSO GOING TO
ADD A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE
NORTHERN CWA VERY LATE TONIGHT INTO EARLY SUNDAY MORNING. LARGE
VORT MAX ENTERING THE FAR NORTHERN PLAINS WILL SINK SOUTHEAST
THROUGH THE UPPER MIDWEST THROUGH SUNDAY MORNING. VORT LOBE OUT
AHEAD OF IT WILL SWING SOUTHEAST TO EASTERN IOWA AND SOUTHWEST
WISCONSIN AND COULD HELP THUNDERSTORM DEVELOPMENT IN THESE
AREAS...ESPECIALLY ALONG COLD FRONTAL BOUNDARY. CONFIDENCE OF
COVERAGE AND INTENSITY IS LOW AT THIS TIME BUT THERE IS A
POSSIBILITY FOR SOME OF THIS DEVELOPMENT TO REACH FAR NORTHERN
ILLINOIS BY VERY LATE TONIGHT AND EARLY SUNDAY MORNING. IF THIS
WERE TO OCCUR...WOULD EXPECT THAT HEAVY DOWNPOURS WOULD BE THE
MAIN THREAT.

VERY MOIST CONDITIONS IN A RELAXED SURFACE PATTERN WILL BE
CONDUCIVE FOR FOG DEVELOPMENT TONIGHT ESPECIALLY AS WINDS FURTHER
DIMINISH...AND SO HAVE ADDED MENTION OF FOG FOR THE ENTIRE CWA
TONIGHT.

RODRIGUEZ

//PREV DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 03Z...

* SOME FOG POSSIBLE OVERNIGHT...MVFR VSBY PROBABLE WITH A CHANCE
  OF IFR VSBY
* GUSTY WNW WINDS DEVELOP SUNDAY AFTERNOON
* SLIGHT CHANCE OF ISOLD SHRA OR TSRA SUNDAY

IZZI

//DISCUSSION...UPDATED 00Z...

DIMINISHING WINDS...CLEARING SKIES...AND VERY MOIST AIR MASS
FILTERING INTO THE AREA WILL SET THE STAGE FOR GROUND FOG TO
DEVELOP TONIGHT. THE MOST DENSE FOG SHOULD BE IN OUTLYING AREAS
BUT IFR CONDITIONS OR LOWER ARE A POSSIBILITY EVEN IN THE URBAN
AREAS. STRONG UPPER TROUGH WILL DIG SOUTHEAST INTO THE GREAT LAKES
REGION SUNDAY MORNING WITH INCREASING WINDS AFTER SUNRISE QUICKLY
MIXING OUT ANY FOG/VSBY EARLY SUNDAY MORNING. WINDS WILL REALLY
RAMP UP BY LATE MORNING/EARLY AFTERNOON SUNDAY AS BEHIND COLD
FRONT MOVING THROUGH THE AREA...GUSTS OF 25-30KT LOOK LIKE A GOOD
BET DURING THE AFTERNOON. NOT OUT OF THE QUESTION THAT THERE
COULD BE ISOLD SHRA OR EVENING TSRA AROUND SUNDAY...BUT EVEN IF
ANY FORM COVERAGE SHOULD BE LOW AND DURATION BRIEF IN ANY GIVEN
LOCATION SO NO REASON TO INCLUDE IN TERMINAL FORECAST AT THIS
TIME.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 03Z...

* MEDIUM-HIGH CONFIDENCE IN VSBY RESTRICTIONS DEVELOPING DUE TO
  FOG OVERNIGHT BUT LOW CONFIDENCE IN HOW LOW VSBYS DROP
* HIGH CONFIDENCE IN OTHER FORECAST ELEMENTS

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

IZZI

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 270037
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
737 PM CDT SAT JUL 26 2014

.DISCUSSION...
736 PM CDT

OVERALL THREAT OF SEVERE WEATHER HAS DIMINISHED IN THE NEAR TERM
AND FOR THE REMAINDER OF THE EVENING...WITH CHANCES APPEARING LOW
FOR ADDITIONAL THUNDERSTORM DEVELOPMENT OVERNIGHT.

LATEST RADAR IMAGERY DEPICTING REMAINING SHOWERY ACTIVITY EXITING
THE SOUTHEAST CWA AS COMPLEX OVER CENTRAL ILLINOIS AND INDIANA
CONTINUES TO PROGRESS TO THE EAST...LEAVING THE CWA AND MUCH OF
THE REGION TO THE NORTH AND NORTHWEST DRY AT THIS TIME. LACK OF
ANY REAL GOOD FOCUS THIS EVENING AND A STRONG CAP STILL IN PLACE
OVER LINGERING STATIONARY BOUNDARY WILL LIMIT FURTHER
STRONG/SEVERE THUNDERSTORM DEVELOPMENT FOR THE REST OF THE
EVENING. DID ADJUST POPS TO KEEP LOW CHANCE/SLIGHT CHANCE POPS FOR
SHOWERS AND THUNDERSTORMS MAINLY FOR THE SOUTHERN CWA WITH THIS
LINGERING BOUNDARY STILL IN PLACE...BUT WITH ANY FURTHER
DEVELOPMENT MORE THAN LIKELY REMAINING MORE SHOWERY. ALSO GOING TO
ADD A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE
NORTHERN CWA VERY LATE TONIGHT INTO EARLY SUNDAY MORNING. LARGE
VORT MAX ENTERING THE FAR NORTHERN PLAINS WILL SINK SOUTHEAST
THROUGH THE UPPER MIDWEST THROUGH SUNDAY MORNING. VORT LOBE OUT
AHEAD OF IT WILL SWING SOUTHEAST TO EASTERN IOWA AND SOUTHWEST
WISCONSIN AND COULD HELP THUNDERSTORM DEVELOPMENT IN THESE
AREAS...ESPECIALLY ALONG COLD FRONTAL BOUNDARY. CONFIDENCE OF
COVERAGE AND INTENSITY IS LOW AT THIS TIME BUT THERE IS A
POSSIBILITY FOR SOME OF THIS DEVELOPMENT TO REACH FAR NORTHERN
ILLINOIS BY VERY LATE TONIGHT AND EARLY SUNDAY MORNING. IF THIS
WERE TO OCCUR...WOULD EXPECT THAT HEAVY DOWNPOURS WOULD BE THE
MAIN THREAT.

VERY MOIST CONDITIONS IN A RELAXED SURFACE PATTERN WILL BE
CONDUCIVE FOR FOG DEVELOPMENT TONIGHT ESPECIALLY AS WINDS FURTHER
DIMINISH...AND SO HAVE ADDED MENTION OF FOG FOR THE ENTIRE CWA
TONIGHT.

RODRIGUEZ

&&

.PREV DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* SOME FOG POSSIBLE OVERNIGHT...MVFR VSBY PROBABLE WITH A CHANCE
  OF IFR VSBY
* GUSTY WNW WINDS DEVELOP SUNDAY AFTERNOON
* SLIGHT CHANCE OF ISOLD SHRA OR TSRA SUNDAY

IZZI

//DISCUSSION...UPDATED 00Z...

DIMINISHING WINDS...CLEARING SKIES...AND VERY MOIST AIR MASS
FILTERING INTO THE AREA WILL SET THE STAGE FOR GROUND FOG TO
DEVELOP TONIGHT. THE MOST DENSE FOG SHOULD BE IN OUTLYING AREAS
BUT IFR CONDITIONS OR LOWER ARE A POSSIBILITY EVEN IN THE URBAN
AREAS. STRONG UPPER TROUGH WILL DIG SOUTHEAST INTO THE GREAT LAKES
REGION SUNDAY MORNING WITH INCREASING WINDS AFTER SUNRISE QUICKLY
MIXING OUT ANY FOG/VSBY EARLY SUNDAY MORNING. WINDS WILL REALLY
RAMP UP BY LATE MORNING/EARLY AFTERNOON SUNDAY AS BEHIND COLD
FRONT MOVING THROUGH THE AREA...GUSTS OF 25-30KT LOOK LIKE A GOOD
BET DURING THE AFTERNOON. NOT OUT OF THE QUESTION THAT THERE
COULD BE ISOLD SHRA OR EVENING TSRA AROUND SUNDAY...BUT EVEN IF
ANY FORM COVERAGE SHOULD BE LOW AND DURATION BRIEF IN ANY GIVEN
LOCATION SO NO REASON TO INCLUDE IN TERMINAL FORECAST AT THIS
TIME.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM-HIGH CONFIDENCE IN VSBY RESTRICTIONS DUE TO FOG TONIGHT
  BUT LOW CONFIDENCE IN HOW LOW VSBYS DROP
* HIGH CONFIDENCE IN OTHER FORECAST ELEMENTS

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

IZZI

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO









000
FXUS63 KLOT 270007
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
707 PM CDT SAT JUL 26 2014

.DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* SOME FOG POSSIBLE OVERNIGHT...MVFR VSBY PROBABLE WITH A CHANCE
  OF IFR VSBY
* GUSTY WNW WINDS DEVELOP SUNDAY AFTERNOON
* SLIGHT CHANCE OF ISOLD SHRA OR TSRA SUNDAY

IZZI

//DISCUSSION...UPDATED 00Z...

DIMINISHING WINDS...CLEARING SKIES...AND VERY MOIST AIR MASS
FILTERING INTO THE AREA WILL SET THE STAGE FOR GROUND FOG TO
DEVELOP TONIGHT. THE MOST DENSE FOG SHOULD BE IN OUTLYING AREAS
BUT IFR CONDITIONS OR LOWER ARE A POSSIBILITY EVEN IN THE URBAN
AREAS. STRONG UPPER TROUGH WILL DIG SOUTHEAST INTO THE GREAT LAKES
REGION SUNDAY MORNING WITH INCREASING WINDS AFTER SUNRISE QUICKLY
MIXING OUT ANY FOG/VSBY EARLY SUNDAY MORNING. WINDS WILL REALLY
RAMP UP BY LATE MORNING/EARLY AFTERNOON SUNDAY AS BEHIND COLD
FRONT MOVING THROUGH THE AREA...GUSTS OF 25-30KT LOOK LIKE A GOOD
BET DURING THE AFTERNOON. NOT OUT OF THE QUESTION THAT THERE
COULD BE ISOLD SHRA OR EVENING TSRA AROUND SUNDAY...BUT EVEN IF
ANY FORM COVERAGE SHOULD BE LOW AND DURATION BRIEF IN ANY GIVEN
LOCATION SO NO REASON TO INCLUDE IN TERMINAL FORECAST AT THIS
TIME.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM-HIGH CONFIDENCE IN VSBY RESTRICTIONS DUE TO FOG TONIGHT
  BUT LOW CONFIDENCE IN HOW LOW VSBYS DROP
* HIGH CONFIDENCE IN OTHER FORECAST ELEMENTS

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

IZZI

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 270007
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
707 PM CDT SAT JUL 26 2014

.DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* SOME FOG POSSIBLE OVERNIGHT...MVFR VSBY PROBABLE WITH A CHANCE
  OF IFR VSBY
* GUSTY WNW WINDS DEVELOP SUNDAY AFTERNOON
* SLIGHT CHANCE OF ISOLD SHRA OR TSRA SUNDAY

IZZI

//DISCUSSION...UPDATED 00Z...

DIMINISHING WINDS...CLEARING SKIES...AND VERY MOIST AIR MASS
FILTERING INTO THE AREA WILL SET THE STAGE FOR GROUND FOG TO
DEVELOP TONIGHT. THE MOST DENSE FOG SHOULD BE IN OUTLYING AREAS
BUT IFR CONDITIONS OR LOWER ARE A POSSIBILITY EVEN IN THE URBAN
AREAS. STRONG UPPER TROUGH WILL DIG SOUTHEAST INTO THE GREAT LAKES
REGION SUNDAY MORNING WITH INCREASING WINDS AFTER SUNRISE QUICKLY
MIXING OUT ANY FOG/VSBY EARLY SUNDAY MORNING. WINDS WILL REALLY
RAMP UP BY LATE MORNING/EARLY AFTERNOON SUNDAY AS BEHIND COLD
FRONT MOVING THROUGH THE AREA...GUSTS OF 25-30KT LOOK LIKE A GOOD
BET DURING THE AFTERNOON. NOT OUT OF THE QUESTION THAT THERE
COULD BE ISOLD SHRA OR EVENING TSRA AROUND SUNDAY...BUT EVEN IF
ANY FORM COVERAGE SHOULD BE LOW AND DURATION BRIEF IN ANY GIVEN
LOCATION SO NO REASON TO INCLUDE IN TERMINAL FORECAST AT THIS
TIME.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM-HIGH CONFIDENCE IN VSBY RESTRICTIONS DUE TO FOG TONIGHT
  BUT LOW CONFIDENCE IN HOW LOW VSBYS DROP
* HIGH CONFIDENCE IN OTHER FORECAST ELEMENTS

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...

MONDAY...VFR. MODERATELY STRONG NORTH-NORTHEAST WINDS.

TUESDAY THROUGH FRIDAY...PREDOMINANTLY VFR THROUGH THE PERIOD.

IZZI

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 262218
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
518 PM CDT SAT JUL 26 2014

.DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 22Z...

* TSRA POTENTIAL EXPECTED TO REMAIN SOUTH OF TERMINALS ACROSS
  CENTRAL IL LATE THIS AFTERNOON/EVENING.

* WEAK LAKE BREEZE LIKELY TO MEANDER AROUND ORD/MDW NEXT FEW HOURS
  BEFORE DISSIPATING...PREVAILING WINDS LESS THAN 10KT

* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT

* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
  AFTERNOON.

* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
  STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON

RATZER/IZZI

//DISCUSSION...UPDATED 22Z...

LAKE BREEZE PUSHED THROUGH ORD BUT HAS BEGAN TO WIGGLE BACK EAST
AND HAS APPROACHED AND THEN STALLED ABOUT 1SM NE OF MDW.
ANTICIPATE LAKE BREEZE WILL CONTINUE TO GIRATE AROUND THE NEXT
COUPLE OF HOURS AND COULD RESULT IN WINDS FLIPPING AND FLOPPING
AROUND...BUT LIKELY TO REMAIN LESS THAN 10KT.

IZZI

UPDATED 18Z...

COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.

DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.

MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.

STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 22Z...

* MEDIUM CONFIDENCE IN SHRA/TSRA STAYING SOUTH OF ORD/MDW THROUGH
  PERIOD

* HIGH CONFIDENCE IN WINDS STAYING LESS THAN 10KT THROUGH TONIGHT
  WITH VARYING DIRECTIONS

* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT

* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY

RATZER/IZZI

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 262218
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
518 PM CDT SAT JUL 26 2014

.DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 22Z...

* TSRA POTENTIAL EXPECTED TO REMAIN SOUTH OF TERMINALS ACROSS
  CENTRAL IL LATE THIS AFTERNOON/EVENING.

* WEAK LAKE BREEZE LIKELY TO MEANDER AROUND ORD/MDW NEXT FEW HOURS
  BEFORE DISSIPATING...PREVAILING WINDS LESS THAN 10KT

* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT

* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
  AFTERNOON.

* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
  STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON

RATZER/IZZI

//DISCUSSION...UPDATED 22Z...

LAKE BREEZE PUSHED THROUGH ORD BUT HAS BEGAN TO WIGGLE BACK EAST
AND HAS APPROACHED AND THEN STALLED ABOUT 1SM NE OF MDW.
ANTICIPATE LAKE BREEZE WILL CONTINUE TO GIRATE AROUND THE NEXT
COUPLE OF HOURS AND COULD RESULT IN WINDS FLIPPING AND FLOPPING
AROUND...BUT LIKELY TO REMAIN LESS THAN 10KT.

IZZI

UPDATED 18Z...

COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.

DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.

MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.

STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 22Z...

* MEDIUM CONFIDENCE IN SHRA/TSRA STAYING SOUTH OF ORD/MDW THROUGH
  PERIOD

* HIGH CONFIDENCE IN WINDS STAYING LESS THAN 10KT THROUGH TONIGHT
  WITH VARYING DIRECTIONS

* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT

* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY

RATZER/IZZI

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 261952
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
252 PM CDT SAT JUL 26 2014

.DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* TSRA POTENTIAL EXPECTED TO REMAIN SOUTH OF TERMINALS ACROSS
  CENTRAL IL LATE THIS AFTERNOON/EVENING.

* VARIABLE SFC WINDS...WITH W-S-SE DIRECTION FAVORED IN NEAR TERM
  BUT LESS THAN 10 KT. LAKE BREEZE HAS STALLED EAST OF ORD/MDW AT
  20Z AND IS EXPECTED TO REMAIN EAST OF AIRFIELDS...THOUGH COULD
  DRIFT WEST AS WINDS DIMINISH FURTHER EARLY EVENING.

* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT.

* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
  AFTERNOON.

* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
  STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON.

RATZER

//DISCUSSION...UPDATED 18Z...

COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.

DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.

MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.

STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* LOW CONFIDENCE IN SHRA/TSRA DIRECTLY AFFECTING ORD/MDW THROUGH
  PERIOD.

* LOW CONFIDENCE IN WIND DIRECTION THIS AFTERNOON AND TONIGHT...
  THOUGH HIGH CONFIDENCE IN PREVAILING SPEEDS LESS THAN 10 KT.

* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT.

* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 261946
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
246 PM CDT SAT JUL 26 2014

.DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* LOW CHANCE ISOLATED SHRA/TSRA THIS AFTERNOON. GREATER TSRA
  POTENTIAL REMAINS SOUTH OF AREA INTO CENTRAL IL LATE THIS
  AFTERNOON/EVENING.

* LIGHT AND SOMEWHAT VARIABLE SFC WINDS INTO TONIGHT. SOME CHANCE
  OF LAKE BREEZE AND SHIFT TO AN EASTERLY DIRECTION MID/LATE
  AFTERNOON.

* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT.

* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
  AFTERNOON.

* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
  STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON.

RATZER

//DISCUSSION...UPDATED 18Z...

COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.

DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.

MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.

STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* LOW CONFIDENCE IN SHRA/TSRA DIRECTLY AFFECTING ORD/MDW THROUGH
  PERIOD.

* LOW CONFIDENCE IN WIND DIRECTION THIS AFTERNOON AND TONIGHT...
  THOUGH HIGH CONFIDENCE IN PREVAILING SPEEDS LESS THAN 10 KT.

* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT.

* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 261946
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
246 PM CDT SAT JUL 26 2014

.DISCUSSION...

246 PM...FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS
THROUGH SUNDAY MORNING.

18Z SOUNDINGS FROM ILX AND DVN THIS AFTERNOON SHOW STRONG CAPPING
IN PLACE ACROSS THE AREA. RADAR IMAGERY SHOWS LIGHT RETURNS WHICH
ARE LIKELY ELEVATED SHOWERS/WEAK CONVECTION ROOTED FROM 800MB...
ABOVE THE CAP. NOT EXPECTING MUCH ACTIVITY ACROSS NORTHERN IL WITH
THIS CAP IN PLACE BUT ISOLATED SHOWERS/SPRINKLES WILL BE POSSIBLE.

THUNDERSTORMS OVER NORTHERN MO CONTINUE MOVING EAST AND INCREASING
IN COVERAGE BUT NOT MUCH ORGANIZATION YET. AS THIS ACTIVITY MOVES
EAST INTO THE MORE CAPPED AIR...IT MAY CONTINUE TO STRUGGLE TO
ORGANIZE INTO A SEVERE LINE/COMPLEX. THUS CONFIDENCE REGARDING
CONVECTIVE TRENDS ACROSS THE SOUTHERN CWA/CENTRAL IL/CENTRAL
INDIANA ARE DECREASING AT THE MOMENT. BUT WITH THE WARM FRONTAL
BOUNDARY NEARBY AND MID 70S DEWPOINTS POOLING SOUTH OF THE
FRONT...HAVE NOT MADE ANY CHANGES TO COVERAGE/TIMING. AND WHILE
SEVERE POTENTIAL REMAINS UNCERTAIN...SHOULD STORMS BECOME SEVERE
EARLIER THOUGHTS REMAIN ON TRACK FOR WIDESPREAD DAMAGING WINDS TO
BE THE MAIN THREAT...MAINLY SOUTH OF THE KANKAKEE RIVER.

THE GRADIENT MAY BECOME WEAK ENOUGH FOR LIGHT/CALM WINDS OVERNIGHT
ESPECIALLY OVER THE SOUTHERN HALF OF THE CWA. WHILE PRECIP
COVERAGE REMAINS UNCERTAIN...LOW LEVELS WILL REMAIN QUITE MOIST
AND FOG WILL BE POSSIBLE...AND WHERE ANY RAIN DOES FALL...COULD
BECOME LOCALLY DENSE.

A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY MORNING...LIKELY
MOVING EAST OF THE CWA BY 18Z. COULD BE ISOLATED/SCATTERED
THUNDERSTORMS ALONG/AHEAD OF THIS FRONT DURING THE MID MORNING
HOURS BUT WILL BE SHORT-LIVED WITH A PERIOD OF DRY CONDITIONS
EXPECTED MIDDAY/EARLY AFTERNOON POST FRONTAL. AS COOLER AIR
SPREADS ACROSS THE AREA...DIURNAL SHOWERS AND PERHAPS A FEW
THUNDERSTORMS WILL BE POSSIBLE MID/LATE SUNDAY AFTERNOON AND THIS
WOULD BE MOST LIKELY ACROSS NORTHERN IL. AS THIS COOLER AND DRIER
AIR ADVECTS INTO THE AREA...LOW LEVEL MIXING WILL BECOME QUITE
EFFICIENT. FORECAST SOUNDINGS SHOW 25-30 KTS IN THE MIXED LAYER
BY LATE AFTERNOON...THUS WINDY CONDITIONS ARE EXPECTED SUNDAY
AFTERNOON WITH WIND GUSTS AS HIGH AS 35 MPH.

A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SUNDAY
NIGHT USHERING IN EVEN COOLER AIR WITH HIGHS ON MONDAY ONLY IN THE
LOWER/MID 70S. A LARGE UPPER TROUGH WILL THEN REMAIN ACROSS MUCH
OF THE GREAT LAKES REGION AND EASTERN U.S. THROUGH THE END OF NEXT
WEEK. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY IN THE MID/
UPPER 70S THROUGH THE END OF NEXT WEEK. IN ADDITION THERE WILL BE
AFTERNOON/EARLY EVENING CHANCES FOR ISOLATED SHOWERS/THUNDERSTORMS
JUST ABOUT EVERYDAY. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* LOW CHANCE ISOLATED SHRA/TSRA THIS AFTERNOON. GREATER TSRA
  POTENTIAL REMAINS SOUTH OF AREA INTO CENTRAL IL LATE THIS
  AFTERNOON/EVENING.

* LIGHT AND SOMEWHAT VARIABLE SFC WINDS INTO TONIGHT. SOME CHANCE
  OF LAKE BREEZE AND SHIFT TO AN EASTERLY DIRECTION MID/LATE
  AFTERNOON.

* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT.

* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
  AFTERNOON.

* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
  STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON.

RATZER

//DISCUSSION...UPDATED 18Z...

COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.

DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.

MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.

STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* LOW CONFIDENCE IN SHRA/TSRA DIRECTLY AFFECTING ORD/MDW THROUGH
  PERIOD.

* LOW CONFIDENCE IN WIND DIRECTION THIS AFTERNOON AND TONIGHT...
  THOUGH HIGH CONFIDENCE IN PREVAILING SPEEDS LESS THAN 10 KT.

* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT.

* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 261927
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
227 PM CDT SAT JUL 26 2014

.DISCUSSION...

1150 AM...LATE MORNING UPDATE...TWO FEATURES OF NOTE LATE THIS
MORNING...A WEAK WAVE OVER SOUTHERN MN THAT WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND WHAT IS EXPECTED TO BE THE MAIN WAVE
CURRENTLY OVER NORTHEAST KS MOVING INTO NORTHWEST MO. FORECAST
SOUNDINGS SHOW A FAIRLY STRONG CAP ACROSS MUCH OF THE AREA INTO
THIS AFTERNOON AND WHILE SHORT TERM/HI RES GUIDANCE DOES SUGGEST
SOME ISOLATED ACTIVITY IS POSSIBLE...APPEARS MUCH OF THE AREA WILL
REMAIN DRY INTO THIS AFTERNOON.

THUNDERSTORMS DEVELOPING OVER NORTHWEST MO WILL CONTINUE MOVING
EAST THIS AFTERNOON AND ACROSS A VERY UNSTABLE/MOIST ATMOSPHERE.
THIS ACTIVITY IS EXPECTED TO CONTINUE EAST AND ACROSS THE
SOUTHERN CWA LATE THIS AFTERNOON OR MORE LIKELY DURING THE EVENING
HOURS. NO CHANGES TO PREVIOUS THOUGHTS ON SEVERE POTENTIAL WITH A
LINE OF STORMS WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS
THE MOST LIKELY THREAT. HOW FAR NORTH THIS LINE EXTENDS IS STILL A
BIT UNCERTAIN AND WHILE IT WILL LIKELY REMAIN SOUTH OF I-80...
COULD BE EVEN FURTHER SOUTH...PERHAPS SOUTH OF THE KANKAKEE RIVER.

OTHERWISE...EXTENSIVE CLOUD COVER IS SLOWING THE WARMING TREND.
WITH VERY WARM LOW LEVELS...A FEW HOURS OF SUN...IF THAT WERE TO
OCCUR...COULD PUSH TEMPS TO CURRENT FORECAST HIGHS OF MID 80S...SO
NO LARGE CHANGES TO HIGHS BUT TEMP TRENDS WILL REQUIRE UPDATES.
CMS

//PREV DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* LOW CHANCE ISOLATED SHRA/TSRA THIS AFTERNOON. GREATER TSRA
  POTENTIAL REMAINS SOUTH OF AREA INTO CENTRAL IL LATE THIS
  AFTERNOON/EVENING.

* LIGHT AND SOMEWHAT VARIABLE SFC WINDS INTO TONIGHT. SOME CHANCE
  OF LAKE BREEZE AND SHIFT TO AN EASTERLY DIRECTION MID/LATE
  AFTERNOON.

* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT.

* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
  AFTERNOON.

* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
  STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON.

RATZER

//DISCUSSION...UPDATED 18Z...

COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.

DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.

MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.

STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* LOW CONFIDENCE IN SHRA/TSRA DIRECTLY AFFECTING ORD/MDW THROUGH
  PERIOD.

* LOW CONFIDENCE IN WIND DIRECTION THIS AFTERNOON AND TONIGHT...
  THOUGH HIGH CONFIDENCE IN PREVAILING SPEEDS LESS THAN 10 KT.

* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT.

* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...NOON SUNDAY TO 11 PM
     MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 261927
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
227 PM CDT SAT JUL 26 2014

.DISCUSSION...

1150 AM...LATE MORNING UPDATE...TWO FEATURES OF NOTE LATE THIS
MORNING...A WEAK WAVE OVER SOUTHERN MN THAT WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND WHAT IS EXPECTED TO BE THE MAIN WAVE
CURRENTLY OVER NORTHEAST KS MOVING INTO NORTHWEST MO. FORECAST
SOUNDINGS SHOW A FAIRLY STRONG CAP ACROSS MUCH OF THE AREA INTO
THIS AFTERNOON AND WHILE SHORT TERM/HI RES GUIDANCE DOES SUGGEST
SOME ISOLATED ACTIVITY IS POSSIBLE...APPEARS MUCH OF THE AREA WILL
REMAIN DRY INTO THIS AFTERNOON.

THUNDERSTORMS DEVELOPING OVER NORTHWEST MO WILL CONTINUE MOVING
EAST THIS AFTERNOON AND ACROSS A VERY UNSTABLE/MOIST ATMOSPHERE.
THIS ACTIVITY IS EXPECTED TO CONTINUE EAST AND ACROSS THE
SOUTHERN CWA LATE THIS AFTERNOON OR MORE LIKELY DURING THE EVENING
HOURS. NO CHANGES TO PREVIOUS THOUGHTS ON SEVERE POTENTIAL WITH A
LINE OF STORMS WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS
THE MOST LIKELY THREAT. HOW FAR NORTH THIS LINE EXTENDS IS STILL A
BIT UNCERTAIN AND WHILE IT WILL LIKELY REMAIN SOUTH OF I-80...
COULD BE EVEN FURTHER SOUTH...PERHAPS SOUTH OF THE KANKAKEE RIVER.

OTHERWISE...EXTENSIVE CLOUD COVER IS SLOWING THE WARMING TREND.
WITH VERY WARM LOW LEVELS...A FEW HOURS OF SUN...IF THAT WERE TO
OCCUR...COULD PUSH TEMPS TO CURRENT FORECAST HIGHS OF MID 80S...SO
NO LARGE CHANGES TO HIGHS BUT TEMP TRENDS WILL REQUIRE UPDATES.
CMS

//PREV DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* LOW CHANCE ISOLATED SHRA/TSRA THIS AFTERNOON. GREATER TSRA
  POTENTIAL REMAINS SOUTH OF AREA INTO CENTRAL IL LATE THIS
  AFTERNOON/EVENING.

* LIGHT AND SOMEWHAT VARIABLE SFC WINDS INTO TONIGHT. SOME CHANCE
  OF LAKE BREEZE AND SHIFT TO AN EASTERLY DIRECTION MID/LATE
  AFTERNOON.

* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT.

* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
  AFTERNOON.

* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
  STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON.

RATZER

//DISCUSSION...UPDATED 18Z...

COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.

DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.

MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.

STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* LOW CONFIDENCE IN SHRA/TSRA DIRECTLY AFFECTING ORD/MDW THROUGH
  PERIOD.

* LOW CONFIDENCE IN WIND DIRECTION THIS AFTERNOON AND TONIGHT...
  THOUGH HIGH CONFIDENCE IN PREVAILING SPEEDS LESS THAN 10 KT.

* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT.

* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
230 PM CDT

AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...NOON SUNDAY TO 11 PM
     MONDAY.

IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
     TUESDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
     PM MONDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
     AM TUESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 261820
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
120 PM CDT SAT JUL 26 2014

.DISCUSSION...

1150 AM...LATE MORNING UPDATE...TWO FEATURES OF NOTE LATE THIS
MORNING...A WEAK WAVE OVER SOUTHERN MN THAT WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND WHAT IS EXPECTED TO BE THE MAIN WAVE
CURRENTLY OVER NORTHEAST KS MOVING INTO NORTHWEST MO. FORECAST
SOUNDINGS SHOW A FAIRLY STRONG CAP ACROSS MUCH OF THE AREA INTO
THIS AFTERNOON AND WHILE SHORT TERM/HI RES GUIDANCE DOES SUGGEST
SOME ISOLATED ACTIVITY IS POSSIBLE...APPEARS MUCH OF THE AREA WILL
REMAIN DRY INTO THIS AFTERNOON.

THUNDERSTORMS DEVELOPING OVER NORTHWEST MO WILL CONTINUE MOVING
EAST THIS AFTERNOON AND ACROSS A VERY UNSTABLE/MOIST ATMOSPHERE.
THIS ACTIVITY IS EXPECTED TO CONTINUE EAST AND ACROSS THE
SOUTHERN CWA LATE THIS AFTERNOON OR MORE LIKELY DURING THE EVENING
HOURS. NO CHANGES TO PREVIOUS THOUGHTS ON SEVERE POTENTIAL WITH A
LINE OF STORMS WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS
THE MOST LIKELY THREAT. HOW FAR NORTH THIS LINE EXTENDS IS STILL A
BIT UNCERTAIN AND WHILE IT WILL LIKELY REMAIN SOUTH OF I-80...
COULD BE EVEN FURTHER SOUTH...PERHAPS SOUTH OF THE KANKAKEE RIVER.

OTHERWISE...EXTENSIVE CLOUD COVER IS SLOWING THE WARMING TREND.
WITH VERY WARM LOW LEVELS...A FEW HOURS OF SUN...IF THAT WERE TO
OCCUR...COULD PUSH TEMPS TO CURRENT FORECAST HIGHS OF MID 80S...SO
NO LARGE CHANGES TO HIGHS BUT TEMP TRENDS WILL REQUIRE UPDATES.
CMS

//PREV DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* LOW CHANCE ISOLATED SHRA/TSRA THIS AFTERNOON. GREATER TSRA
  POTENTIAL REMAINS SOUTH OF AREA INTO CENTRAL IL LATE THIS
  AFTERNOON/EVENING.

* LIGHT AND SOMEWHAT VARIABLE SFC WINDS INTO TONIGHT. SOME CHANCE
  OF LAKE BREEZE AND SHIFT TO AN EASTERLY DIRECTION MID/LATE
  AFTERNOON.

* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT.

* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
  AFTERNOON.

* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
  STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON.

RATZER

//DISCUSSION...UPDATED 18Z...

COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.

DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.

MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.

STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.

RATZER


//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* LOW CONFIDENCE IN SHRA/TSRA DIRECTLY AFFECTING ORD/MDW THROUGH
  PERIOD.

* LOW CONFIDENCE IN WIND DIRECTION THIS AFTERNOON AND TONIGHT...
  THOUGH HIGH CONFIDENCE IN PREVAILING SPEEDS LESS THAN 10 KT.

* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT.

* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 261820
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
120 PM CDT SAT JUL 26 2014

.DISCUSSION...

1150 AM...LATE MORNING UPDATE...TWO FEATURES OF NOTE LATE THIS
MORNING...A WEAK WAVE OVER SOUTHERN MN THAT WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND WHAT IS EXPECTED TO BE THE MAIN WAVE
CURRENTLY OVER NORTHEAST KS MOVING INTO NORTHWEST MO. FORECAST
SOUNDINGS SHOW A FAIRLY STRONG CAP ACROSS MUCH OF THE AREA INTO
THIS AFTERNOON AND WHILE SHORT TERM/HI RES GUIDANCE DOES SUGGEST
SOME ISOLATED ACTIVITY IS POSSIBLE...APPEARS MUCH OF THE AREA WILL
REMAIN DRY INTO THIS AFTERNOON.

THUNDERSTORMS DEVELOPING OVER NORTHWEST MO WILL CONTINUE MOVING
EAST THIS AFTERNOON AND ACROSS A VERY UNSTABLE/MOIST ATMOSPHERE.
THIS ACTIVITY IS EXPECTED TO CONTINUE EAST AND ACROSS THE
SOUTHERN CWA LATE THIS AFTERNOON OR MORE LIKELY DURING THE EVENING
HOURS. NO CHANGES TO PREVIOUS THOUGHTS ON SEVERE POTENTIAL WITH A
LINE OF STORMS WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS
THE MOST LIKELY THREAT. HOW FAR NORTH THIS LINE EXTENDS IS STILL A
BIT UNCERTAIN AND WHILE IT WILL LIKELY REMAIN SOUTH OF I-80...
COULD BE EVEN FURTHER SOUTH...PERHAPS SOUTH OF THE KANKAKEE RIVER.

OTHERWISE...EXTENSIVE CLOUD COVER IS SLOWING THE WARMING TREND.
WITH VERY WARM LOW LEVELS...A FEW HOURS OF SUN...IF THAT WERE TO
OCCUR...COULD PUSH TEMPS TO CURRENT FORECAST HIGHS OF MID 80S...SO
NO LARGE CHANGES TO HIGHS BUT TEMP TRENDS WILL REQUIRE UPDATES.
CMS

//PREV DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* LOW CHANCE ISOLATED SHRA/TSRA THIS AFTERNOON. GREATER TSRA
  POTENTIAL REMAINS SOUTH OF AREA INTO CENTRAL IL LATE THIS
  AFTERNOON/EVENING.

* LIGHT AND SOMEWHAT VARIABLE SFC WINDS INTO TONIGHT. SOME CHANCE
  OF LAKE BREEZE AND SHIFT TO AN EASTERLY DIRECTION MID/LATE
  AFTERNOON.

* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT.

* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
  AFTERNOON.

* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
  STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON.

RATZER

//DISCUSSION...UPDATED 18Z...

COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.

DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.

MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.

STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.

RATZER


//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* LOW CONFIDENCE IN SHRA/TSRA DIRECTLY AFFECTING ORD/MDW THROUGH
  PERIOD.

* LOW CONFIDENCE IN WIND DIRECTION THIS AFTERNOON AND TONIGHT...
  THOUGH HIGH CONFIDENCE IN PREVAILING SPEEDS LESS THAN 10 KT.

* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT.

* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 261650
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1150 AM CDT SAT JUL 26 2014

.DISCUSSION...

1150 AM...LATE MORNING UPDATE...TWO FEATURES OF NOTE LATE THIS
MORNING...A WEAK WAVE OVER SOUTHERN MN THAT WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND WHAT IS EXPECTED TO BE THE MAIN WAVE
CURRENTLY OVER NORTHEAST KS MOVING INTO NORTHWEST MO. FORECAST
SOUNDINGS SHOW A FAIRLY STRONG CAP ACROSS MUCH OF THE AREA INTO
THIS AFTERNOON AND WHILE SHORT TERM/HI RES GUIDANCE DOES SUGGEST
SOME ISOLATED ACTIVITY IS POSSIBLE...APPEARS MUCH OF THE AREA WILL
REMAIN DRY INTO THIS AFTERNOON.

THUNDERSTORMS DEVELOPING OVER NORTHWEST MO WILL CONTINUE MOVING
EAST THIS AFTERNOON AND ACROSS A VERY UNSTABLE/MOIST ATMOSPHERE.
THIS ACTIVITY IS EXPECTED TO CONTINUE EAST AND ACROSS THE
SOUTHERN CWA LATE THIS AFTERNOON OR MORE LIKELY DURING THE EVENING
HOURS. NO CHANGES TO PREVIOUS THOUGHTS ON SEVERE POTENTIAL WITH A
LINE OF STORMS WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS
THE MOST LIKELY THREAT. HOW FAR NORTH THIS LINE EXTENDS IS STILL A
BIT UNCERTAIN AND WHILE IT WILL LIKELY REMAIN SOUTH OF I-80...
COULD BE EVEN FURTHER SOUTH...PERHAPS SOUTH OF THE KANKAKEE RIVER.

OTHERWISE...EXTENSIVE CLOUD COVER IS SLOWING THE WARMING TREND.
WITH VERY WARM LOW LEVELS...A FEW HOURS OF SUN...IF THAT WERE TO
OCCUR...COULD PUSH TEMPS TO CURRENT FORECAST HIGHS OF MID 80S...SO
NO LARGE CHANGES TO HIGHS BUT TEMP TRENDS WILL REQUIRE UPDATES.
CMS

&&

.PREV DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* PERIOD OF MVFR CIGS 2000-2500 FT THROUGH LATE MORNING.

* SMALL THREAT OF SHRA/TSRA TODAY AND THIS EVENING...WITH MAIN
  STORM COVERAGE EXPECTED ACROSS OR SOUTH OF THE SOUTHERN C-90
  TRACON AREA ESPECIALLY THIS EVE.

* MAINLY WEST-SOUTHWEST WIND UNDER 10 KT...THOUGH SOME VARIABILITY
  IN WEAK FLOW. POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE
  MID-LATE THIS AFTERNOON.

* POSSIBLE FOG AND/OR LOWER CIGS TONIGHT.

RATZER

//DISCUSSION...UPDATED 12Z...

A BROAD SURFACE LOW PRESSURE TROUGH FROM KS NORTHEAST THROUGH WI
WILL INCH EASTWARD TODAY. INCREASING MOISTURE AHEAD OF THIS WILL
CONTINUE TO FAVOR 2500-4000 FT CIGS THIS MORNING. ISOLATED SHOWERS
ON MOIST AIR ALOFT WILL MOVE SOUTHEAST BY MID-MORNING. WHILE
THERE IS A SMALL CHANCE FOR SHRA/TSRA THE REMAINDER OF TODAY
ASSOCIATED WITH A STRONG JET ALOFT OVER A MOIST
ATMOSPHERE...CHANCES AND COVERAGE LOOK SMALL ENOUGH TO PRECLUDE
MENTION IN MOST OF THE TAFS. THUNDERSTORM DEVELOPMENT IS EXPECTED
LATER THIS AFTERNOON INTO THIS EVE ACROSS CENTRAL IL POTENTIALLY
AS FAR NORTH AS THE SOUTHERN TRACON AREA. HOWEVER...STORMS ARE NOT
PRESENTLY EXPECTED AS FAR NORTH AS ORD AND MDW.

THE WIND FORECAST IS CHALLENGING TODAY DUE TO A LIGHT PRESSURE
GRADIENT. CLOUDS THIS MORNING AND POSSIBLY THROUGH A GOOD PART OF
THE DAY WILL LIKELY SUBDUE MIXING SOME AND PREVENT WESTERLY WINDS
AS STRONG AS SOME MODELS ARE INDICATING. A LAKE BREEZE WILL LIKELY
DEVELOP AND PROGRESS WESTWARD...BUT HOW FAR REACHING IS DIFFICULT
TO SAY...ALONG WITH HOW STRONG WIND SPEEDS WILL BE BEHIND IT.
CONTINUE TO INDICATE IT REACHING ORD AND MDW WITH THE BEST TIME
ESTIMATE ALTHOUGH CONFIDENCE IS LOW ON THAT.

LIGHT WIND SPEEDS EXPECTED TONIGHT ALONG WITH HIGH LOW-LEVEL
MOISTURE WILL PROBABLY SET THE STAGE FOR SOME VISIBILITY AND/OR CIG
RESTRICTIONS INTO THE MVFR CATEGORY. SOME MODEL GUIDANCE IS
INDICATING IFR CONDITIONS ARE POSSIBLE...AND BELIEVE THAT IF MID-
LEVEL CLOUDS CAN CLEAR THEN THAT WILL UNFOLD. BUT RIGHT NOW DO NOT
HAVE MUCH CONFIDENCE IN THAT.

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* HIGH IN PERIOD OF MVFR CIGS LATE THIS MORNING...2000 FT OR
  HIGHER.

* LOW IN ANY SHRA/TSRA OCCURRING TODAY AND THIS EVE...BUT IF ANY
  OCCUR THEY SHOULD BE SHORT-LIVED.

* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY WIND SHIFT OCCURS LATER THIS AFTERNOON. MEDIUM IN
  WIND SPEED REMAINING BELOW 10 KT.

* LOW IN FOG AND LOW CIGS TONIGHT.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 261650
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1150 AM CDT SAT JUL 26 2014

.DISCUSSION...

1150 AM...LATE MORNING UPDATE...TWO FEATURES OF NOTE LATE THIS
MORNING...A WEAK WAVE OVER SOUTHERN MN THAT WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND WHAT IS EXPECTED TO BE THE MAIN WAVE
CURRENTLY OVER NORTHEAST KS MOVING INTO NORTHWEST MO. FORECAST
SOUNDINGS SHOW A FAIRLY STRONG CAP ACROSS MUCH OF THE AREA INTO
THIS AFTERNOON AND WHILE SHORT TERM/HI RES GUIDANCE DOES SUGGEST
SOME ISOLATED ACTIVITY IS POSSIBLE...APPEARS MUCH OF THE AREA WILL
REMAIN DRY INTO THIS AFTERNOON.

THUNDERSTORMS DEVELOPING OVER NORTHWEST MO WILL CONTINUE MOVING
EAST THIS AFTERNOON AND ACROSS A VERY UNSTABLE/MOIST ATMOSPHERE.
THIS ACTIVITY IS EXPECTED TO CONTINUE EAST AND ACROSS THE
SOUTHERN CWA LATE THIS AFTERNOON OR MORE LIKELY DURING THE EVENING
HOURS. NO CHANGES TO PREVIOUS THOUGHTS ON SEVERE POTENTIAL WITH A
LINE OF STORMS WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS
THE MOST LIKELY THREAT. HOW FAR NORTH THIS LINE EXTENDS IS STILL A
BIT UNCERTAIN AND WHILE IT WILL LIKELY REMAIN SOUTH OF I-80...
COULD BE EVEN FURTHER SOUTH...PERHAPS SOUTH OF THE KANKAKEE RIVER.

OTHERWISE...EXTENSIVE CLOUD COVER IS SLOWING THE WARMING TREND.
WITH VERY WARM LOW LEVELS...A FEW HOURS OF SUN...IF THAT WERE TO
OCCUR...COULD PUSH TEMPS TO CURRENT FORECAST HIGHS OF MID 80S...SO
NO LARGE CHANGES TO HIGHS BUT TEMP TRENDS WILL REQUIRE UPDATES.
CMS

&&

.PREV DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* PERIOD OF MVFR CIGS 2000-2500 FT THROUGH LATE MORNING.

* SMALL THREAT OF SHRA/TSRA TODAY AND THIS EVENING...WITH MAIN
  STORM COVERAGE EXPECTED ACROSS OR SOUTH OF THE SOUTHERN C-90
  TRACON AREA ESPECIALLY THIS EVE.

* MAINLY WEST-SOUTHWEST WIND UNDER 10 KT...THOUGH SOME VARIABILITY
  IN WEAK FLOW. POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE
  MID-LATE THIS AFTERNOON.

* POSSIBLE FOG AND/OR LOWER CIGS TONIGHT.

RATZER

//DISCUSSION...UPDATED 12Z...

A BROAD SURFACE LOW PRESSURE TROUGH FROM KS NORTHEAST THROUGH WI
WILL INCH EASTWARD TODAY. INCREASING MOISTURE AHEAD OF THIS WILL
CONTINUE TO FAVOR 2500-4000 FT CIGS THIS MORNING. ISOLATED SHOWERS
ON MOIST AIR ALOFT WILL MOVE SOUTHEAST BY MID-MORNING. WHILE
THERE IS A SMALL CHANCE FOR SHRA/TSRA THE REMAINDER OF TODAY
ASSOCIATED WITH A STRONG JET ALOFT OVER A MOIST
ATMOSPHERE...CHANCES AND COVERAGE LOOK SMALL ENOUGH TO PRECLUDE
MENTION IN MOST OF THE TAFS. THUNDERSTORM DEVELOPMENT IS EXPECTED
LATER THIS AFTERNOON INTO THIS EVE ACROSS CENTRAL IL POTENTIALLY
AS FAR NORTH AS THE SOUTHERN TRACON AREA. HOWEVER...STORMS ARE NOT
PRESENTLY EXPECTED AS FAR NORTH AS ORD AND MDW.

THE WIND FORECAST IS CHALLENGING TODAY DUE TO A LIGHT PRESSURE
GRADIENT. CLOUDS THIS MORNING AND POSSIBLY THROUGH A GOOD PART OF
THE DAY WILL LIKELY SUBDUE MIXING SOME AND PREVENT WESTERLY WINDS
AS STRONG AS SOME MODELS ARE INDICATING. A LAKE BREEZE WILL LIKELY
DEVELOP AND PROGRESS WESTWARD...BUT HOW FAR REACHING IS DIFFICULT
TO SAY...ALONG WITH HOW STRONG WIND SPEEDS WILL BE BEHIND IT.
CONTINUE TO INDICATE IT REACHING ORD AND MDW WITH THE BEST TIME
ESTIMATE ALTHOUGH CONFIDENCE IS LOW ON THAT.

LIGHT WIND SPEEDS EXPECTED TONIGHT ALONG WITH HIGH LOW-LEVEL
MOISTURE WILL PROBABLY SET THE STAGE FOR SOME VISIBILITY AND/OR CIG
RESTRICTIONS INTO THE MVFR CATEGORY. SOME MODEL GUIDANCE IS
INDICATING IFR CONDITIONS ARE POSSIBLE...AND BELIEVE THAT IF MID-
LEVEL CLOUDS CAN CLEAR THEN THAT WILL UNFOLD. BUT RIGHT NOW DO NOT
HAVE MUCH CONFIDENCE IN THAT.

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* HIGH IN PERIOD OF MVFR CIGS LATE THIS MORNING...2000 FT OR
  HIGHER.

* LOW IN ANY SHRA/TSRA OCCURRING TODAY AND THIS EVE...BUT IF ANY
  OCCUR THEY SHOULD BE SHORT-LIVED.

* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY WIND SHIFT OCCURS LATER THIS AFTERNOON. MEDIUM IN
  WIND SPEED REMAINING BELOW 10 KT.

* LOW IN FOG AND LOW CIGS TONIGHT.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 261610
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1110 AM CDT SAT JUL 26 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* PERIOD OF MVFR CIGS 2000-2500 FT THROUGH LATE MORNING.

* SMALL THREAT OF SHRA/TSRA TODAY AND THIS EVENING...WITH MAIN
  STORM COVERAGE EXPECTED ACROSS OR SOUTH OF THE SOUTHERN C-90
  TRACON AREA ESPECIALLY THIS EVE.

* MAINLY WEST-SOUTHWEST WIND UNDER 10 KT...THOUGH SOME VARIABILITY
  IN WEAK FLOW. POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE
  MID-LATE THIS AFTERNOON.

* POSSIBLE FOG AND/OR LOWER CIGS TONIGHT.

RATZER

//DISCUSSION...UPDATED 12Z...

A BROAD SURFACE LOW PRESSURE TROUGH FROM KS NORTHEAST THROUGH WI
WILL INCH EASTWARD TODAY. INCREASING MOISTURE AHEAD OF THIS WILL
CONTINUE TO FAVOR 2500-4000 FT CIGS THIS MORNING. ISOLATED SHOWERS
ON MOIST AIR ALOFT WILL MOVE SOUTHEAST BY MID-MORNING. WHILE
THERE IS A SMALL CHANCE FOR SHRA/TSRA THE REMAINDER OF TODAY
ASSOCIATED WITH A STRONG JET ALOFT OVER A MOIST
ATMOSPHERE...CHANCES AND COVERAGE LOOK SMALL ENOUGH TO PRECLUDE
MENTION IN MOST OF THE TAFS. THUNDERSTORM DEVELOPMENT IS EXPECTED
LATER THIS AFTERNOON INTO THIS EVE ACROSS CENTRAL IL POTENTIALLY
AS FAR NORTH AS THE SOUTHERN TRACON AREA. HOWEVER...STORMS ARE NOT
PRESENTLY EXPECTED AS FAR NORTH AS ORD AND MDW.

THE WIND FORECAST IS CHALLENGING TODAY DUE TO A LIGHT PRESSURE
GRADIENT. CLOUDS THIS MORNING AND POSSIBLY THROUGH A GOOD PART OF
THE DAY WILL LIKELY SUBDUE MIXING SOME AND PREVENT WESTERLY WINDS
AS STRONG AS SOME MODELS ARE INDICATING. A LAKE BREEZE WILL LIKELY
DEVELOP AND PROGRESS WESTWARD...BUT HOW FAR REACHING IS DIFFICULT
TO SAY...ALONG WITH HOW STRONG WIND SPEEDS WILL BE BEHIND IT.
CONTINUE TO INDICATE IT REACHING ORD AND MDW WITH THE BEST TIME
ESTIMATE ALTHOUGH CONFIDENCE IS LOW ON THAT.

LIGHT WIND SPEEDS EXPECTED TONIGHT ALONG WITH HIGH LOW-LEVEL
MOISTURE WILL PROBABLY SET THE STAGE FOR SOME VISIBILITY AND/OR CIG
RESTRICTIONS INTO THE MVFR CATEGORY. SOME MODEL GUIDANCE IS
INDICATING IFR CONDITIONS ARE POSSIBLE...AND BELIEVE THAT IF MID-
LEVEL CLOUDS CAN CLEAR THEN THAT WILL UNFOLD. BUT RIGHT NOW DO NOT
HAVE MUCH CONFIDENCE IN THAT.

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* HIGH IN PERIOD OF MVFR CIGS LATE THIS MORNING...2000 FT OR
  HIGHER.

* LOW IN ANY SHRA/TSRA OCCURRING TODAY AND THIS EVE...BUT IF ANY
  OCCUR THEY SHOULD BE SHORT-LIVED.

* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY WIND SHIFT OCCURS LATER THIS AFTERNOON. MEDIUM IN
  WIND SPEED REMAINING BELOW 10 KT.

* LOW IN FOG AND LOW CIGS TONIGHT.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 261610
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1110 AM CDT SAT JUL 26 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* PERIOD OF MVFR CIGS 2000-2500 FT THROUGH LATE MORNING.

* SMALL THREAT OF SHRA/TSRA TODAY AND THIS EVENING...WITH MAIN
  STORM COVERAGE EXPECTED ACROSS OR SOUTH OF THE SOUTHERN C-90
  TRACON AREA ESPECIALLY THIS EVE.

* MAINLY WEST-SOUTHWEST WIND UNDER 10 KT...THOUGH SOME VARIABILITY
  IN WEAK FLOW. POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE
  MID-LATE THIS AFTERNOON.

* POSSIBLE FOG AND/OR LOWER CIGS TONIGHT.

RATZER

//DISCUSSION...UPDATED 12Z...

A BROAD SURFACE LOW PRESSURE TROUGH FROM KS NORTHEAST THROUGH WI
WILL INCH EASTWARD TODAY. INCREASING MOISTURE AHEAD OF THIS WILL
CONTINUE TO FAVOR 2500-4000 FT CIGS THIS MORNING. ISOLATED SHOWERS
ON MOIST AIR ALOFT WILL MOVE SOUTHEAST BY MID-MORNING. WHILE
THERE IS A SMALL CHANCE FOR SHRA/TSRA THE REMAINDER OF TODAY
ASSOCIATED WITH A STRONG JET ALOFT OVER A MOIST
ATMOSPHERE...CHANCES AND COVERAGE LOOK SMALL ENOUGH TO PRECLUDE
MENTION IN MOST OF THE TAFS. THUNDERSTORM DEVELOPMENT IS EXPECTED
LATER THIS AFTERNOON INTO THIS EVE ACROSS CENTRAL IL POTENTIALLY
AS FAR NORTH AS THE SOUTHERN TRACON AREA. HOWEVER...STORMS ARE NOT
PRESENTLY EXPECTED AS FAR NORTH AS ORD AND MDW.

THE WIND FORECAST IS CHALLENGING TODAY DUE TO A LIGHT PRESSURE
GRADIENT. CLOUDS THIS MORNING AND POSSIBLY THROUGH A GOOD PART OF
THE DAY WILL LIKELY SUBDUE MIXING SOME AND PREVENT WESTERLY WINDS
AS STRONG AS SOME MODELS ARE INDICATING. A LAKE BREEZE WILL LIKELY
DEVELOP AND PROGRESS WESTWARD...BUT HOW FAR REACHING IS DIFFICULT
TO SAY...ALONG WITH HOW STRONG WIND SPEEDS WILL BE BEHIND IT.
CONTINUE TO INDICATE IT REACHING ORD AND MDW WITH THE BEST TIME
ESTIMATE ALTHOUGH CONFIDENCE IS LOW ON THAT.

LIGHT WIND SPEEDS EXPECTED TONIGHT ALONG WITH HIGH LOW-LEVEL
MOISTURE WILL PROBABLY SET THE STAGE FOR SOME VISIBILITY AND/OR CIG
RESTRICTIONS INTO THE MVFR CATEGORY. SOME MODEL GUIDANCE IS
INDICATING IFR CONDITIONS ARE POSSIBLE...AND BELIEVE THAT IF MID-
LEVEL CLOUDS CAN CLEAR THEN THAT WILL UNFOLD. BUT RIGHT NOW DO NOT
HAVE MUCH CONFIDENCE IN THAT.

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* HIGH IN PERIOD OF MVFR CIGS LATE THIS MORNING...2000 FT OR
  HIGHER.

* LOW IN ANY SHRA/TSRA OCCURRING TODAY AND THIS EVE...BUT IF ANY
  OCCUR THEY SHOULD BE SHORT-LIVED.

* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY WIND SHIFT OCCURS LATER THIS AFTERNOON. MEDIUM IN
  WIND SPEED REMAINING BELOW 10 KT.

* LOW IN FOG AND LOW CIGS TONIGHT.

RATZER

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 261406
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
906 AM CDT SAT JUL 26 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 14Z...

* SMALL CHANCE FOR MVFR CIGS THIS MORNING.
* SMALL THREAT OF SHRA/TSRA TODAY AND THIS EVENING...WITH MAIN
  STORM COVERAGE ACROSS OR SOUTH OF THE SOUTHERN C-90 TRACON AREA
  ESPECIALLY THIS EVE.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE MID-LATE THIS
  AFTERNOON.
* POSSIBLE FOG AND/OR LOWER CIGS TONIGHT.

//DISCUSSION...UPDATED 12Z...

A BROAD SURFACE LOW PRESSURE TROUGH FROM KS NORTHEAST THROUGH WI
WILL INCH EASTWARD TODAY. INCREASING MOISTURE AHEAD OF THIS WILL
CONTINUE TO FAVOR 2500-4000 FT CIGS THIS MORNING. ISOLATED SHOWERS
ON MOIST AIR ALOFT WILL MOVE SOUTHEAST BY MID-MORNING. WHILE
THERE IS A SMALL CHANCE FOR SHRA/TSRA THE REMAINDER OF TODAY
ASSOCIATED WITH A STRONG JET ALOFT OVER A MOIST
ATMOSPHERE...CHANCES AND COVERAGE LOOK SMALL ENOUGH TO PRECLUDE
MENTION IN MOST OF THE TAFS. THUNDERSTORM DEVELOPMENT IS EXPECTED
LATER THIS AFTERNOON INTO THIS EVE ACROSS CENTRAL IL POTENTIALLY
AS FAR NORTH AS THE SOUTHERN TRACON AREA. HOWEVER...STORMS ARE NOT
PRESENTLY EXPECTED AS FAR NORTH AS ORD AND MDW.

THE WIND FORECAST IS CHALLENGING TODAY DUE TO A LIGHT PRESSURE
GRADIENT. CLOUDS THIS MORNING AND POSSIBLY THROUGH A GOOD PART OF
THE DAY WILL LIKELY SUBDUE MIXING SOME AND PREVENT WESTERLY WINDS
AS STRONG AS SOME MODELS ARE INDICATING. A LAKE BREEZE WILL LIKELY
DEVELOP AND PROGRESS WESTWARD...BUT HOW FAR REACHING IS DIFFICULT
TO SAY...ALONG WITH HOW STRONG WIND SPEEDS WILL BE BEHIND IT.
CONTINUE TO INDICATE IT REACHING ORD AND MDW WITH THE BEST TIME
ESTIMATE ALTHOUGH CONFIDENCE IS LOW ON THAT.

LIGHT WIND SPEEDS EXPECTED TONIGHT ALONG WITH HIGH LOW-LEVEL
MOISTURE WILL PROBABLY SET THE STAGE FOR SOME VISIBILITY AND/OR CIG
RESTRICTIONS INTO THE MVFR CATEGORY. SOME MODEL GUIDANCE IS
INDICATING IFR CONDITIONS ARE POSSIBLE...AND BELIEVE THAT IF MID-
LEVEL CLOUDS CAN CLEAR THEN THAT WILL UNFOLD. BUT RIGHT NOW DO NOT
HAVE MUCH CONFIDENCE IN THAT.

//ORD AND MDW CONFIDENCE...UPDATED 14Z...

* HIGH IN THAT ANY MVFR CIGS THIS MORNING BEING ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA OCCURRING TODAY AND THIS EVE...BUT IF ANY
  OCCUR THEY SHOULD BE SHORT-LIVED.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY WIND SHIFT OCCURS LATER THIS AFTERNOON. MEDIUM IN
  WIND SPEED REMAINING BELOW 10 KT.
* LOW IN FOG AND LOW CIGS TONIGHT.

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 261406
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
906 AM CDT SAT JUL 26 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 14Z...

* SMALL CHANCE FOR MVFR CIGS THIS MORNING.
* SMALL THREAT OF SHRA/TSRA TODAY AND THIS EVENING...WITH MAIN
  STORM COVERAGE ACROSS OR SOUTH OF THE SOUTHERN C-90 TRACON AREA
  ESPECIALLY THIS EVE.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE MID-LATE THIS
  AFTERNOON.
* POSSIBLE FOG AND/OR LOWER CIGS TONIGHT.

//DISCUSSION...UPDATED 12Z...

A BROAD SURFACE LOW PRESSURE TROUGH FROM KS NORTHEAST THROUGH WI
WILL INCH EASTWARD TODAY. INCREASING MOISTURE AHEAD OF THIS WILL
CONTINUE TO FAVOR 2500-4000 FT CIGS THIS MORNING. ISOLATED SHOWERS
ON MOIST AIR ALOFT WILL MOVE SOUTHEAST BY MID-MORNING. WHILE
THERE IS A SMALL CHANCE FOR SHRA/TSRA THE REMAINDER OF TODAY
ASSOCIATED WITH A STRONG JET ALOFT OVER A MOIST
ATMOSPHERE...CHANCES AND COVERAGE LOOK SMALL ENOUGH TO PRECLUDE
MENTION IN MOST OF THE TAFS. THUNDERSTORM DEVELOPMENT IS EXPECTED
LATER THIS AFTERNOON INTO THIS EVE ACROSS CENTRAL IL POTENTIALLY
AS FAR NORTH AS THE SOUTHERN TRACON AREA. HOWEVER...STORMS ARE NOT
PRESENTLY EXPECTED AS FAR NORTH AS ORD AND MDW.

THE WIND FORECAST IS CHALLENGING TODAY DUE TO A LIGHT PRESSURE
GRADIENT. CLOUDS THIS MORNING AND POSSIBLY THROUGH A GOOD PART OF
THE DAY WILL LIKELY SUBDUE MIXING SOME AND PREVENT WESTERLY WINDS
AS STRONG AS SOME MODELS ARE INDICATING. A LAKE BREEZE WILL LIKELY
DEVELOP AND PROGRESS WESTWARD...BUT HOW FAR REACHING IS DIFFICULT
TO SAY...ALONG WITH HOW STRONG WIND SPEEDS WILL BE BEHIND IT.
CONTINUE TO INDICATE IT REACHING ORD AND MDW WITH THE BEST TIME
ESTIMATE ALTHOUGH CONFIDENCE IS LOW ON THAT.

LIGHT WIND SPEEDS EXPECTED TONIGHT ALONG WITH HIGH LOW-LEVEL
MOISTURE WILL PROBABLY SET THE STAGE FOR SOME VISIBILITY AND/OR CIG
RESTRICTIONS INTO THE MVFR CATEGORY. SOME MODEL GUIDANCE IS
INDICATING IFR CONDITIONS ARE POSSIBLE...AND BELIEVE THAT IF MID-
LEVEL CLOUDS CAN CLEAR THEN THAT WILL UNFOLD. BUT RIGHT NOW DO NOT
HAVE MUCH CONFIDENCE IN THAT.

//ORD AND MDW CONFIDENCE...UPDATED 14Z...

* HIGH IN THAT ANY MVFR CIGS THIS MORNING BEING ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA OCCURRING TODAY AND THIS EVE...BUT IF ANY
  OCCUR THEY SHOULD BE SHORT-LIVED.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY WIND SHIFT OCCURS LATER THIS AFTERNOON. MEDIUM IN
  WIND SPEED REMAINING BELOW 10 KT.
* LOW IN FOG AND LOW CIGS TONIGHT.

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED
12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 261138
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
638 AM CDT SAT JUL 26 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 12Z...

* SMALL CHANCE FOR MVFR CIGS THIS MORNING.
* SMALL THREAT OF SHRA/TSRA TODAY AND THIS EVENING...WITH MAIN
  STORM COVERAGE ACROSS THE SOUTHERN TRACON AREA NAMELY THIS EVE.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE MID-LATE THIS
  AFTERNOON.
* POSSIBLE FOG AND/OR LOWER CIGS TONIGHT.


//DISCUSSION...UPDATED 12Z...

A BROAD SURFACE LOW PRESSURE TROUGH FROM KS NORTHEAST THROUGH WI
WILL INCH EASTWARD TODAY. INCREASING MOISTURE AHEAD OF THIS WILL
CONTINUE TO FAVOR 2500-4000 FT CIGS THIS MORNING. ISOLATED SHOWERS
ON MOIST AIR ALOFT WILL MOVE SOUTHEAST BY MID-MORNING. WHILE
THERE IS A SMALL CHANCE FOR SHRA/TSRA THE REMAINDER OF TODAY
ASSOCIATED WITH A STRONG JET ALOFT OVER A MOIST
ATMOSPHERE...CHANCES AND COVERAGE LOOK SMALL ENOUGH TO PRECLUDE
MENTION IN MOST OF THE TAFS. THUNDERSTORM DEVELOPMENT IS EXPECTED
LATER THIS AFTERNOON INTO THIS EVE ACROSS CENTRAL IL POTENTIALLY
AS FAR NORTH AS THE SOUTHERN TRACON AREA. HOWEVER...STORMS ARE NOT
PRESENTLY EXPECTED AS FAR NORTH AS ORD AND MDW.

THE WIND FORECAST IS CHALLENGING TODAY DUE TO A LIGHT PRESSURE
GRADIENT. CLOUDS THIS MORNING AND POSSIBLY THROUGH A GOOD PART OF
THE DAY WILL LIKELY SUBDUE MIXING SOME AND PREVENT WESTERLY WINDS
AS STRONG AS SOME MODELS ARE INDICATING. A LAKE BREEZE WILL LIKELY
DEVELOP AND PROGRESS WESTWARD...BUT HOW FAR REACHING IS DIFFICULT
TO SAY...ALONG WITH HOW STRONG WIND SPEEDS WILL BE BEHIND IT.
CONTINUE TO INDICATE IT REACHING ORD AND MDW WITH THE BEST TIME
ESTIMATE ALTHOUGH CONFIDENCE IS LOW ON THAT.

LIGHT WIND SPEEDS EXPECTED TONIGHT ALONG WITH HIGH LOW-LEVEL
MOISTURE WILL PROBABLY SET THE STAGE FOR SOME VISIBILITY AND/OR CIG
RESTRICTIONS INTO THE MVFR CATEGORY. SOME MODEL GUIDANCE IS
INDICATING IFR CONDITIONS ARE POSSIBLE...AND BELIEVE THAT IF MID-
LEVEL CLOUDS CAN CLEAR THEN THAT WILL UNFOLD. BUT RIGHT NOW DO NOT
HAVE MUCH CONFIDENCE IN THAT.


//ORD AND MDW CONFIDENCE...UPDATED 12Z...

* HIGH IN THAT ANY MVFR CIGS THIS MORNING BEING ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA OCCURRING TODAY AND THIS EVE...BUT IF ANY
  OCCUR THEY SHOULD BE SHORT-LIVED.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY WIND SHIFT OCCURS LATER THIS AFTERNOON. MEDIUM IN
  WIND SPEED REMAINING BELOW 10 KT.
* LOW IN FOG AND LOW CIGS TONIGHT.


//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 261138
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
638 AM CDT SAT JUL 26 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 12Z...

* SMALL CHANCE FOR MVFR CIGS THIS MORNING.
* SMALL THREAT OF SHRA/TSRA TODAY AND THIS EVENING...WITH MAIN
  STORM COVERAGE ACROSS THE SOUTHERN TRACON AREA NAMELY THIS EVE.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE MID-LATE THIS
  AFTERNOON.
* POSSIBLE FOG AND/OR LOWER CIGS TONIGHT.


//DISCUSSION...UPDATED 12Z...

A BROAD SURFACE LOW PRESSURE TROUGH FROM KS NORTHEAST THROUGH WI
WILL INCH EASTWARD TODAY. INCREASING MOISTURE AHEAD OF THIS WILL
CONTINUE TO FAVOR 2500-4000 FT CIGS THIS MORNING. ISOLATED SHOWERS
ON MOIST AIR ALOFT WILL MOVE SOUTHEAST BY MID-MORNING. WHILE
THERE IS A SMALL CHANCE FOR SHRA/TSRA THE REMAINDER OF TODAY
ASSOCIATED WITH A STRONG JET ALOFT OVER A MOIST
ATMOSPHERE...CHANCES AND COVERAGE LOOK SMALL ENOUGH TO PRECLUDE
MENTION IN MOST OF THE TAFS. THUNDERSTORM DEVELOPMENT IS EXPECTED
LATER THIS AFTERNOON INTO THIS EVE ACROSS CENTRAL IL POTENTIALLY
AS FAR NORTH AS THE SOUTHERN TRACON AREA. HOWEVER...STORMS ARE NOT
PRESENTLY EXPECTED AS FAR NORTH AS ORD AND MDW.

THE WIND FORECAST IS CHALLENGING TODAY DUE TO A LIGHT PRESSURE
GRADIENT. CLOUDS THIS MORNING AND POSSIBLY THROUGH A GOOD PART OF
THE DAY WILL LIKELY SUBDUE MIXING SOME AND PREVENT WESTERLY WINDS
AS STRONG AS SOME MODELS ARE INDICATING. A LAKE BREEZE WILL LIKELY
DEVELOP AND PROGRESS WESTWARD...BUT HOW FAR REACHING IS DIFFICULT
TO SAY...ALONG WITH HOW STRONG WIND SPEEDS WILL BE BEHIND IT.
CONTINUE TO INDICATE IT REACHING ORD AND MDW WITH THE BEST TIME
ESTIMATE ALTHOUGH CONFIDENCE IS LOW ON THAT.

LIGHT WIND SPEEDS EXPECTED TONIGHT ALONG WITH HIGH LOW-LEVEL
MOISTURE WILL PROBABLY SET THE STAGE FOR SOME VISIBILITY AND/OR CIG
RESTRICTIONS INTO THE MVFR CATEGORY. SOME MODEL GUIDANCE IS
INDICATING IFR CONDITIONS ARE POSSIBLE...AND BELIEVE THAT IF MID-
LEVEL CLOUDS CAN CLEAR THEN THAT WILL UNFOLD. BUT RIGHT NOW DO NOT
HAVE MUCH CONFIDENCE IN THAT.


//ORD AND MDW CONFIDENCE...UPDATED 12Z...

* HIGH IN THAT ANY MVFR CIGS THIS MORNING BEING ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA OCCURRING TODAY AND THIS EVE...BUT IF ANY
  OCCUR THEY SHOULD BE SHORT-LIVED.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY WIND SHIFT OCCURS LATER THIS AFTERNOON. MEDIUM IN
  WIND SPEED REMAINING BELOW 10 KT.
* LOW IN FOG AND LOW CIGS TONIGHT.


//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...

SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.

MTF

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 260845
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
345 AM CDT SAT JUL 26 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 09Z...

* MVFR CIGS POSSIBLE THROUGH MID-MORNING.
* SMALL THREAT OF SHRA/TSRA TODAY AND THIS EVENING...WITH GREATER
  STORM COVERAGE ACROSS SOUTHERN TRACON AREA NAMELY THIS EVE.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE LATE THIS
  AFTERNOON.

//DISCUSSION...UPDATED 06Z...

A DIFFUSE LOW-LEVEL TROUGH FROM MN DOWN TO KS CONTINUES TO INCH
EASTWARD. MOISTURE CONTINUES TO SLOWLY INCREASE ACROSS THE AREA
AHEAD OF THIS. WITH THAT INCREASE...2000-3500 FT CIGS ARE
WIDESPREAD ACROSS NORTHERN IA/WI/NORTHERN IL AND EXPECTING THAT
OVER THE TAF SITES THROUGH AT LEAST DAYBREAK AND LIKELY A FEW
HOURS LONGER. THERE IS SOME INDICATION ROCKFORD COULD DROP DOWN TO
NEAR 1000 FT AROUND DAYBREAK. WARM AIR ADVECTION ASCENT MAY BE
ENOUGH PRIOR TO DAYBREAK TO SPARK A FEW SHRA/TSRA BUT MAINLY SOUTH
OF THE TAF SITES. CONVECTION EXPECTED PRIOR TO DAYBREAK ACROSS
PARTS OF SD INTO NW/NC IA IS EXPECTED TO WEAKEN THIS MORNING AS IT
SHIFTS EAST. SO WHILE CANNOT RULE OUT AND SHRA/TSRA TODAY...THE
FORCING IS PRETTY NEBULOUS DESPITE HIGH MOISTURE AROUND. SO HAVE
KEPT THE TAFS PRIMARILY DRY. THE BETTER FOCUS TONIGHT WILL BE
ALONG A WARM FRONT BOUNDARY DRAPED ACROSS CENTRAL IL AND IN.

WINDS ARE A CHALLENGE TODAY DUE PARTLY TO THE LIGHT GRADIENT AND
MORNING CLOUD COVER LIKELY TO INHIBIT MIXING TO SOME DEGREE. IT
WOULD APPEAR A LAKE BREEZE WILL DEVELOP BUT HOW FAR INLAND THIS
PROPAGATES IS THE MAIN UNCERTAINTY. HAVE OPTED TO INCLUDE IN THIS
SET OF TAFS BUT NOT MENTION A WIND SHIFT AT ORD UNTIL LATE IN THE
DAY/EARLY EVE...AS ANY LAKE BREEZE ARRIVAL WOULD LIKELY BE LATER.

//ORD AND MDW CONFIDENCE...UPDATED 09Z...

* LOW IN WHETHER CIGS WILL DROP BELOW 3000 FT THIS MORNING...HOWEVER
  IF THEY DO CONFIDENCE IS HIGH THEY WILL REMAIN ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA THROUGH THE DAY TODAY BUT ANY ARE LIKELY TO
  BE TEMPORARY.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN AFTERNOON EASTERLY SHIFT WILL OCCUR AT BOTH AIRPORTS.

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

MTF/IZZI

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 260822
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
322 AM CDT SAT JUL 26 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR CIGS LIKELY AT TIMES THROUGH MID-MORNING.
* SMALL THREAT OF SHRA/TSRA THROUGH THIS MORNING.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE LATE THIS
  AFTERNOON.

//DISCUSSION...UPDATED 06Z...

A DIFFUSE LOW-LEVEL TROUGH FROM MN DOWN TO KS CONTINUES TO INCH
EASTWARD. MOISTURE CONTINUES TO SLOWLY INCREASE ACROSS THE AREA
AHEAD OF THIS. WITH THAT INCREASE...2000-3500 FT CIGS ARE
WIDESPREAD ACROSS NORTHERN IA/WI/NORTHERN IL AND EXPECTING THAT
OVER THE TAF SITES THROUGH AT LEAST DAYBREAK AND LIKELY A FEW
HOURS LONGER. THERE IS SOME INDICATION ROCKFORD COULD DROP DOWN TO
NEAR 1000 FT AROUND DAYBREAK. WARM AIR ADVECTION ASCENT MAY BE
ENOUGH PRIOR TO DAYBREAK TO SPARK A FEW SHRA/TSRA BUT MAINLY SOUTH
OF THE TAF SITES. CONVECTION EXPECTED PRIOR TO DAYBREAK ACROSS
PARTS OF SD INTO NW/NC IA IS EXPECTED TO WEAKEN THIS MORNING AS IT
SHIFTS EAST. SO WHILE CANNOT RULE OUT AND SHRA/TSRA TODAY...THE
FORCING IS PRETTY NEBULOUS DESPITE HIGH MOISTURE AROUND. SO HAVE
KEPT THE TAFS PRIMARILY DRY. THE BETTER FOCUS TONIGHT WILL BE
ALONG A WARM FRONT BOUNDARY DRAPED ACROSS CENTRAL IL AND IN.

WINDS ARE A CHALLENGE TODAY DUE PARTLY TO THE LIGHT GRADIENT AND
MORNING CLOUD COVER LIKELY TO INHIBIT MIXING TO SOME DEGREE. IT
WOULD APPEAR A LAKE BREEZE WILL DEVELOP BUT HOW FAR INLAND THIS
PROPAGATES IS THE MAIN UNCERTAINTY. HAVE OPTED TO INCLUDE IN THIS
SET OF TAFS BUT NOT MENTION A WIND SHIFT AT ORD UNTIL LATE IN THE
DAY/EARLY EVE...AS ANY LAKE BREEZE ARRIVAL WOULD LIKELY BE LATER.

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH IN MVFR CIGS OCCURRING THROUGH AT LEAST 12Z AND MEDIUM IN
  BASES REMAINING ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA THROUGH THE DAY TODAY BUT ANY ARE LIKELY TO
  BE TEMPORARY.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY SHIFT WILL OCCUR AT BOTH AIRPORTS.

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

MTF/IZZI

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO











000
FXUS63 KLOT 260822
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
322 AM CDT SAT JUL 26 2014

.DISCUSSION...
322 AM CDT

SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80.  COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.

TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.

UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING.  AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.

A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.

HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE.  HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.

FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY.  IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.

SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK.  THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.

EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.

HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.

MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY.  IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK.  HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.

JEE

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR CIGS LIKELY AT TIMES THROUGH MID-MORNING.
* SMALL THREAT OF SHRA/TSRA THROUGH THIS MORNING.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE LATE THIS
  AFTERNOON.

//DISCUSSION...UPDATED 06Z...

A DIFFUSE LOW-LEVEL TROUGH FROM MN DOWN TO KS CONTINUES TO INCH
EASTWARD. MOISTURE CONTINUES TO SLOWLY INCREASE ACROSS THE AREA
AHEAD OF THIS. WITH THAT INCREASE...2000-3500 FT CIGS ARE
WIDESPREAD ACROSS NORTHERN IA/WI/NORTHERN IL AND EXPECTING THAT
OVER THE TAF SITES THROUGH AT LEAST DAYBREAK AND LIKELY A FEW
HOURS LONGER. THERE IS SOME INDICATION ROCKFORD COULD DROP DOWN TO
NEAR 1000 FT AROUND DAYBREAK. WARM AIR ADVECTION ASCENT MAY BE
ENOUGH PRIOR TO DAYBREAK TO SPARK A FEW SHRA/TSRA BUT MAINLY SOUTH
OF THE TAF SITES. CONVECTION EXPECTED PRIOR TO DAYBREAK ACROSS
PARTS OF SD INTO NW/NC IA IS EXPECTED TO WEAKEN THIS MORNING AS IT
SHIFTS EAST. SO WHILE CANNOT RULE OUT AND SHRA/TSRA TODAY...THE
FORCING IS PRETTY NEBULOUS DESPITE HIGH MOISTURE AROUND. SO HAVE
KEPT THE TAFS PRIMARILY DRY. THE BETTER FOCUS TONIGHT WILL BE
ALONG A WARM FRONT BOUNDARY DRAPED ACROSS CENTRAL IL AND IN.

WINDS ARE A CHALLENGE TODAY DUE PARTLY TO THE LIGHT GRADIENT AND
MORNING CLOUD COVER LIKELY TO INHIBIT MIXING TO SOME DEGREE. IT
WOULD APPEAR A LAKE BREEZE WILL DEVELOP BUT HOW FAR INLAND THIS
PROPAGATES IS THE MAIN UNCERTAINTY. HAVE OPTED TO INCLUDE IN THIS
SET OF TAFS BUT NOT MENTION A WIND SHIFT AT ORD UNTIL LATE IN THE
DAY/EARLY EVE...AS ANY LAKE BREEZE ARRIVAL WOULD LIKELY BE LATER.

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH IN MVFR CIGS OCCURRING THROUGH AT LEAST 12Z AND MEDIUM IN
  BASES REMAINING ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA THROUGH THE DAY TODAY BUT ANY ARE LIKELY TO
  BE TEMPORARY.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY SHIFT WILL OCCUR AT BOTH AIRPORTS.

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

MTF/IZZI

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO










000
FXUS63 KLOT 260717
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
217 AM CDT SAT JUL 26 2014

.DISCUSSION...
656 PM CDT

MAIN FORECAST UPDATES WERE TO REMOVE POPS THIS EVENING...AND THEN
SHIFT HIGHEST POPS TO THE SOUTHERN THIRD OF THE CWA AFTER MIDNIGHT
TONIGHT.

DEPARTING WAVE TO THE EAST THIS PAST AFTERNOON HAS ALLOWED FOR
DRIER CONDITIONS TO REMAIN IN PLACE EARLY THIS EVENING ACROSS ALL
OF NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH LATEST RADAR
MOSAIC SHOWING LITTLE OR NO PRECIP OVER THE ENTIRE REGION AT THIS
HOUR. WHILE WEAK FORCING ALOFT WILL REMAIN IN PLACE OWING TO WEAK
MID LEVEL IMPULSES APPROACHING FROM THE WEST A LACK OF SURFACE
FOCUS IN A HIGHLY CAPPED ENVIRONMENT...12-16C 700MB TEMPS PER RAP
ANALYSIS...WILL LIMIT ANY DEVELOPMENT THIS EVENING. OUTSIDE OF A
STRAY SPRINKLE OR LIGHT SHOWER...THIS EVENING WILL REMAIN MOSTLY
DRY AND SO HAVE DROPPED POPS DURING THIS PERIOD. WARM FRONT TO THE
SOUTHWEST WILL SLOWLY MOVE NORTH NORTHEAST OVERNIGHT WHILE
INCREASING LLJ AND WAA HELP DEVELOP SOME SHOWERS AND THUNDERSTORMS
AFTER MIDNIGHT. THE BULK OF THIS PRECIP WILL LIKELY REMAIN
CONFINED TO AREAS ALONG AND SOUTH OF INTERSTATE 80 AS IT SLIDES
EAST SOUTHEAST WITH THE VEERING LLJ...WITH THE STRONGEST STORMS
PRODUCING BRIEF HEAVY DOWNPOURS.

CURRENT CLEAR SKIES OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WILL QUICKLY BECOME CLOUDY ONCE AGAIN THIS EVENING...AS STRATUS
DECK SPREADS EAST AND MID LEVEL CLOUDS DEVELOP OVERNIGHT.

RODRIGUEZ

//PREV DISCUSSION...

254 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM CHANCES AND
TIMING THROUGH SUNDAY EVENING...HIGH TEMPS THIS WEEKEND AND THEN
MUCH COOLER TEMPS EARLY NEXT WEEK.

CONFIDENCE REGARDING CONVECTIVE TRENDS OVER THE NEXT 12 TO 18
HOURS IS FAIRLY LOW. A WEAK UPPER WAVE IS MOVING EAST/SOUTHEAST
ACROSS SOUTHERN WISCONSIN WHICH MAY ALLOW ISOLATED ACTIVITY TO
DEVELOP OVER THE NEXT FEW HOURS. ISOLATED ACTIVITY OVER WESTERN IL
APPEARS TO BE ON THE TRAILING EDGE OF THE WAVE PUSHING ACROSS
SOUTHERN IL BUT ALSO ALONG AN INSTABILITY AXIS EXTENDING INTO
EASTERN IA. SHORT TERM/HI RES GUIDANCE SUGGESTS JUST ISOLATED
COVERAGE THROUGH EARLY THIS EVENING THEN DRY THROUGH LATE EVENING
AND POSSIBLY INTO THE OVERNIGHT HOURS.

AS LOW LEVEL MOISTURE RETURNS TONIGHT ANOTHER WAVE CURRENTLY OVER
EASTERN SOUTH DAKOTA MAY AID THUNDERSTORM DEVELOPMENT OVERNIGHT
TOWARD SUNRISE AND PERHAPS OVER THE EASTERN CWA DEPENDING ON
WHEN...AND IF...ANYTHING DOES DEVELOP...THEN EXIT TO THE SOUTHEAST
QUICKLY SATURDAY MORNING. OPTED TO MAINTAIN LIKELY POPS FOR THIS
TIME PERIOD BUT THERE IS LITTLE CONTINUITY IN THE MODELS AND ITS
POSSIBLE MUCH OF THE OVERNIGHT COULD END UP DRY.

TRENDS BECOME A BIT MORE CONFIDENT ON SATURDAY AS THE NORTHERN CWA
REMAINS CAPPED BUT INSTABILITY ACROSS THE SOUTHERN CWA/CENTRAL IL
INCREASES BY LATE AFTERNOON FOR EXPECTED THUNDERSTORM DEVELOPMENT.
THE SEVERE THREAT WOULD BE PRIMARILY DAMAGING WINDS BUT WITH
DEWPOINTS SURGING BACK INTO THE 70S...HEAVY RAIN WILL BE POSSIBLE
AND WITH TRAINING OF STORMS OVER THE SAME AREAS...SOME POTENTIAL
FOR FLOODING WILL ALSO BE POSSIBLE. BULK OF THIS ACTIVITY APPEARS
TO REMAIN SOUTH OF THE I-80 CORRIDOR WITH THE ACTIVITY MOVING
SOUTHEAST OF THE CWA SATURDAY NIGHT.

HIGH TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON THUNDERSTORMS...
AND HOW SOON THEY FORM AS WELL AS CLOUD COVER. LOW LEVEL THERMAL
PROFILES WOULD SUGGEST UPPER 80S TO AROUND 90 IS DOABLE BUT MADE
NO CHANGES TO CURRENT FORECAST OF MID/UPPER 80S. WITH LITTLE
CHANGE TO AIRMASS SATURDAY NIGHT...AND LIKELY WET GROUND ACROSS
THE SOUTHERN CWA...COMBINED WITH LIGHT WINDS...FOG DEVELOPMENT
SEEMS LIKELY LATE SATURDAY NIGHT INTO SUNDAY MORNING...PRIMARILY
ACROSS THE SOUTHERN CWA.

LOW PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SUNDAY WITH A
TRAILING COLD FRONT MOVING ACROSS THE AREA SUNDAY MORNING. WINDS
WILL SHIFT WEST/NORTHWEST BEHIND THE FRONT AND FORECAST SOUNDINGS
SUGGEST IT WOULD BECOME QUITE BREEZY/WINDY SUNDAY AFTERNOON. ANY
THUNDERSTORM POTENTIAL WOULD LIKELY BE SHORT-LIVED AND ALONG/AHEAD
OF THE FRONT.

A SECOND COLD FRONT/SURGE OF COLDER AIR WILL THEN MOVE SOUTH
ACROSS THE WESTERN LAKES SUNDAY NIGHT. THIS COULD TRIGGER A FEW
SHOWERS OVERNIGHT BUT BULK OF THIS ACTIVITY SHOULD REMAIN
NORTHEAST OF THE CWA. WINDS WILL SHIFT NORTHERLY BEHIND THIS FRONT
WITH HIGHS ON MONDAY ONLY IN THE LOWER/MID 70S. TEMPS MODERATE
BACK INTO THE UPPER 70S/NEAR 80 BY THE MIDDLE OF NEXT WEEK WITH
PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS...MAINLY IN THE
AFTERNOON/EARLY EVENING. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR CIGS LIKELY AT TIMES THROUGH MID-MORNING.
* SMALL THREAT OF SHRA/TSRA THROUGH THIS MORNING.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE LATE THIS
  AFTERNOON.

//DISCUSSION...UPDATED 06Z...

A DIFFUSE LOW-LEVEL TROUGH FROM MN DOWN TO KS CONTINUES TO INCH
EASTWARD. MOISTURE CONTINUES TO SLOWLY INCREASE ACROSS THE AREA
AHEAD OF THIS. WITH THAT INCREASE...2000-3500 FT CIGS ARE
WIDESPREAD ACROSS NORTHERN IA/WI/NORTHERN IL AND EXPECTING THAT
OVER THE TAF SITES THROUGH AT LEAST DAYBREAK AND LIKELY A FEW
HOURS LONGER. THERE IS SOME INDICATION ROCKFORD COULD DROP DOWN TO
NEAR 1000 FT AROUND DAYBREAK. WARM AIR ADVECTION ASCENT MAY BE
ENOUGH PRIOR TO DAYBREAK TO SPARK A FEW SHRA/TSRA BUT MAINLY SOUTH
OF THE TAF SITES. CONVECTION EXPECTED PRIOR TO DAYBREAK ACROSS
PARTS OF SD INTO NW/NC IA IS EXPECTED TO WEAKEN THIS MORNING AS IT
SHIFTS EAST. SO WHILE CANNOT RULE OUT AND SHRA/TSRA TODAY...THE
FORCING IS PRETTY NEBULOUS DESPITE HIGH MOISTURE AROUND. SO HAVE
KEPT THE TAFS PRIMARILY DRY. THE BETTER FOCUS TONIGHT WILL BE
ALONG A WARM FRONT BOUNDARY DRAPED ACROSS CENTRAL IL AND IN.

WINDS ARE A CHALLENGE TODAY DUE PARTLY TO THE LIGHT GRADIENT AND
MORNING CLOUD COVER LIKELY TO INHIBIT MIXING TO SOME DEGREE. IT
WOULD APPEAR A LAKE BREEZE WILL DEVELOP BUT HOW FAR INLAND THIS
PROPAGATES IS THE MAIN UNCERTAINTY. HAVE OPTED TO INCLUDE IN THIS
SET OF TAFS BUT NOT MENTION A WIND SHIFT AT ORD UNTIL LATE IN THE
DAY/EARLY EVE...AS ANY LAKE BREEZE ARRIVAL WOULD LIKELY BE LATER.

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH IN MVFR CIGS OCCURRING THROUGH AT LEAST 12Z AND MEDIUM IN
  BASES REMAINING ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA THROUGH THE DAY TODAY BUT ANY ARE LIKELY TO
  BE TEMPORARY.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY SHIFT WILL OCCUR AT BOTH AIRPORTS.

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

MTF/IZZI

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 260717
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
217 AM CDT SAT JUL 26 2014

.DISCUSSION...
656 PM CDT

MAIN FORECAST UPDATES WERE TO REMOVE POPS THIS EVENING...AND THEN
SHIFT HIGHEST POPS TO THE SOUTHERN THIRD OF THE CWA AFTER MIDNIGHT
TONIGHT.

DEPARTING WAVE TO THE EAST THIS PAST AFTERNOON HAS ALLOWED FOR
DRIER CONDITIONS TO REMAIN IN PLACE EARLY THIS EVENING ACROSS ALL
OF NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH LATEST RADAR
MOSAIC SHOWING LITTLE OR NO PRECIP OVER THE ENTIRE REGION AT THIS
HOUR. WHILE WEAK FORCING ALOFT WILL REMAIN IN PLACE OWING TO WEAK
MID LEVEL IMPULSES APPROACHING FROM THE WEST A LACK OF SURFACE
FOCUS IN A HIGHLY CAPPED ENVIRONMENT...12-16C 700MB TEMPS PER RAP
ANALYSIS...WILL LIMIT ANY DEVELOPMENT THIS EVENING. OUTSIDE OF A
STRAY SPRINKLE OR LIGHT SHOWER...THIS EVENING WILL REMAIN MOSTLY
DRY AND SO HAVE DROPPED POPS DURING THIS PERIOD. WARM FRONT TO THE
SOUTHWEST WILL SLOWLY MOVE NORTH NORTHEAST OVERNIGHT WHILE
INCREASING LLJ AND WAA HELP DEVELOP SOME SHOWERS AND THUNDERSTORMS
AFTER MIDNIGHT. THE BULK OF THIS PRECIP WILL LIKELY REMAIN
CONFINED TO AREAS ALONG AND SOUTH OF INTERSTATE 80 AS IT SLIDES
EAST SOUTHEAST WITH THE VEERING LLJ...WITH THE STRONGEST STORMS
PRODUCING BRIEF HEAVY DOWNPOURS.

CURRENT CLEAR SKIES OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WILL QUICKLY BECOME CLOUDY ONCE AGAIN THIS EVENING...AS STRATUS
DECK SPREADS EAST AND MID LEVEL CLOUDS DEVELOP OVERNIGHT.

RODRIGUEZ

//PREV DISCUSSION...

254 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM CHANCES AND
TIMING THROUGH SUNDAY EVENING...HIGH TEMPS THIS WEEKEND AND THEN
MUCH COOLER TEMPS EARLY NEXT WEEK.

CONFIDENCE REGARDING CONVECTIVE TRENDS OVER THE NEXT 12 TO 18
HOURS IS FAIRLY LOW. A WEAK UPPER WAVE IS MOVING EAST/SOUTHEAST
ACROSS SOUTHERN WISCONSIN WHICH MAY ALLOW ISOLATED ACTIVITY TO
DEVELOP OVER THE NEXT FEW HOURS. ISOLATED ACTIVITY OVER WESTERN IL
APPEARS TO BE ON THE TRAILING EDGE OF THE WAVE PUSHING ACROSS
SOUTHERN IL BUT ALSO ALONG AN INSTABILITY AXIS EXTENDING INTO
EASTERN IA. SHORT TERM/HI RES GUIDANCE SUGGESTS JUST ISOLATED
COVERAGE THROUGH EARLY THIS EVENING THEN DRY THROUGH LATE EVENING
AND POSSIBLY INTO THE OVERNIGHT HOURS.

AS LOW LEVEL MOISTURE RETURNS TONIGHT ANOTHER WAVE CURRENTLY OVER
EASTERN SOUTH DAKOTA MAY AID THUNDERSTORM DEVELOPMENT OVERNIGHT
TOWARD SUNRISE AND PERHAPS OVER THE EASTERN CWA DEPENDING ON
WHEN...AND IF...ANYTHING DOES DEVELOP...THEN EXIT TO THE SOUTHEAST
QUICKLY SATURDAY MORNING. OPTED TO MAINTAIN LIKELY POPS FOR THIS
TIME PERIOD BUT THERE IS LITTLE CONTINUITY IN THE MODELS AND ITS
POSSIBLE MUCH OF THE OVERNIGHT COULD END UP DRY.

TRENDS BECOME A BIT MORE CONFIDENT ON SATURDAY AS THE NORTHERN CWA
REMAINS CAPPED BUT INSTABILITY ACROSS THE SOUTHERN CWA/CENTRAL IL
INCREASES BY LATE AFTERNOON FOR EXPECTED THUNDERSTORM DEVELOPMENT.
THE SEVERE THREAT WOULD BE PRIMARILY DAMAGING WINDS BUT WITH
DEWPOINTS SURGING BACK INTO THE 70S...HEAVY RAIN WILL BE POSSIBLE
AND WITH TRAINING OF STORMS OVER THE SAME AREAS...SOME POTENTIAL
FOR FLOODING WILL ALSO BE POSSIBLE. BULK OF THIS ACTIVITY APPEARS
TO REMAIN SOUTH OF THE I-80 CORRIDOR WITH THE ACTIVITY MOVING
SOUTHEAST OF THE CWA SATURDAY NIGHT.

HIGH TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON THUNDERSTORMS...
AND HOW SOON THEY FORM AS WELL AS CLOUD COVER. LOW LEVEL THERMAL
PROFILES WOULD SUGGEST UPPER 80S TO AROUND 90 IS DOABLE BUT MADE
NO CHANGES TO CURRENT FORECAST OF MID/UPPER 80S. WITH LITTLE
CHANGE TO AIRMASS SATURDAY NIGHT...AND LIKELY WET GROUND ACROSS
THE SOUTHERN CWA...COMBINED WITH LIGHT WINDS...FOG DEVELOPMENT
SEEMS LIKELY LATE SATURDAY NIGHT INTO SUNDAY MORNING...PRIMARILY
ACROSS THE SOUTHERN CWA.

LOW PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SUNDAY WITH A
TRAILING COLD FRONT MOVING ACROSS THE AREA SUNDAY MORNING. WINDS
WILL SHIFT WEST/NORTHWEST BEHIND THE FRONT AND FORECAST SOUNDINGS
SUGGEST IT WOULD BECOME QUITE BREEZY/WINDY SUNDAY AFTERNOON. ANY
THUNDERSTORM POTENTIAL WOULD LIKELY BE SHORT-LIVED AND ALONG/AHEAD
OF THE FRONT.

A SECOND COLD FRONT/SURGE OF COLDER AIR WILL THEN MOVE SOUTH
ACROSS THE WESTERN LAKES SUNDAY NIGHT. THIS COULD TRIGGER A FEW
SHOWERS OVERNIGHT BUT BULK OF THIS ACTIVITY SHOULD REMAIN
NORTHEAST OF THE CWA. WINDS WILL SHIFT NORTHERLY BEHIND THIS FRONT
WITH HIGHS ON MONDAY ONLY IN THE LOWER/MID 70S. TEMPS MODERATE
BACK INTO THE UPPER 70S/NEAR 80 BY THE MIDDLE OF NEXT WEEK WITH
PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS...MAINLY IN THE
AFTERNOON/EARLY EVENING. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR CIGS LIKELY AT TIMES THROUGH MID-MORNING.
* SMALL THREAT OF SHRA/TSRA THROUGH THIS MORNING.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE LATE THIS
  AFTERNOON.

//DISCUSSION...UPDATED 06Z...

A DIFFUSE LOW-LEVEL TROUGH FROM MN DOWN TO KS CONTINUES TO INCH
EASTWARD. MOISTURE CONTINUES TO SLOWLY INCREASE ACROSS THE AREA
AHEAD OF THIS. WITH THAT INCREASE...2000-3500 FT CIGS ARE
WIDESPREAD ACROSS NORTHERN IA/WI/NORTHERN IL AND EXPECTING THAT
OVER THE TAF SITES THROUGH AT LEAST DAYBREAK AND LIKELY A FEW
HOURS LONGER. THERE IS SOME INDICATION ROCKFORD COULD DROP DOWN TO
NEAR 1000 FT AROUND DAYBREAK. WARM AIR ADVECTION ASCENT MAY BE
ENOUGH PRIOR TO DAYBREAK TO SPARK A FEW SHRA/TSRA BUT MAINLY SOUTH
OF THE TAF SITES. CONVECTION EXPECTED PRIOR TO DAYBREAK ACROSS
PARTS OF SD INTO NW/NC IA IS EXPECTED TO WEAKEN THIS MORNING AS IT
SHIFTS EAST. SO WHILE CANNOT RULE OUT AND SHRA/TSRA TODAY...THE
FORCING IS PRETTY NEBULOUS DESPITE HIGH MOISTURE AROUND. SO HAVE
KEPT THE TAFS PRIMARILY DRY. THE BETTER FOCUS TONIGHT WILL BE
ALONG A WARM FRONT BOUNDARY DRAPED ACROSS CENTRAL IL AND IN.

WINDS ARE A CHALLENGE TODAY DUE PARTLY TO THE LIGHT GRADIENT AND
MORNING CLOUD COVER LIKELY TO INHIBIT MIXING TO SOME DEGREE. IT
WOULD APPEAR A LAKE BREEZE WILL DEVELOP BUT HOW FAR INLAND THIS
PROPAGATES IS THE MAIN UNCERTAINTY. HAVE OPTED TO INCLUDE IN THIS
SET OF TAFS BUT NOT MENTION A WIND SHIFT AT ORD UNTIL LATE IN THE
DAY/EARLY EVE...AS ANY LAKE BREEZE ARRIVAL WOULD LIKELY BE LATER.

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH IN MVFR CIGS OCCURRING THROUGH AT LEAST 12Z AND MEDIUM IN
  BASES REMAINING ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA THROUGH THE DAY TODAY BUT ANY ARE LIKELY TO
  BE TEMPORARY.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY SHIFT WILL OCCUR AT BOTH AIRPORTS.

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

MTF/IZZI

&&

.MARINE...
217 AM CDT

AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 260546
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1246 AM CDT SAT JUL 26 2014

.DISCUSSION...
656 PM CDT

MAIN FORECAST UPDATES WERE TO REMOVE POPS THIS EVENING...AND THEN
SHIFT HIGHEST POPS TO THE SOUTHERN THIRD OF THE CWA AFTER MIDNIGHT
TONIGHT.

DEPARTING WAVE TO THE EAST THIS PAST AFTERNOON HAS ALLOWED FOR
DRIER CONDITIONS TO REMAIN IN PLACE EARLY THIS EVENING ACROSS ALL
OF NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH LATEST RADAR
MOSAIC SHOWING LITTLE OR NO PRECIP OVER THE ENTIRE REGION AT THIS
HOUR. WHILE WEAK FORCING ALOFT WILL REMAIN IN PLACE OWING TO WEAK
MID LEVEL IMPULSES APPROACHING FROM THE WEST A LACK OF SURFACE
FOCUS IN A HIGHLY CAPPED ENVIRONMENT...12-16C 700MB TEMPS PER RAP
ANALYSIS...WILL LIMIT ANY DEVELOPMENT THIS EVENING. OUTSIDE OF A
STRAY SPRINKLE OR LIGHT SHOWER...THIS EVENING WILL REMAIN MOSTLY
DRY AND SO HAVE DROPPED POPS DURING THIS PERIOD. WARM FRONT TO THE
SOUTHWEST WILL SLOWLY MOVE NORTH NORTHEAST OVERNIGHT WHILE
INCREASING LLJ AND WAA HELP DEVELOP SOME SHOWERS AND THUNDERSTORMS
AFTER MIDNIGHT. THE BULK OF THIS PRECIP WILL LIKELY REMAIN
CONFINED TO AREAS ALONG AND SOUTH OF INTERSTATE 80 AS IT SLIDES
EAST SOUTHEAST WITH THE VEERING LLJ...WITH THE STRONGEST STORMS
PRODUCING BRIEF HEAVY DOWNPOURS.

CURRENT CLEAR SKIES OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WILL QUICKLY BECOME CLOUDY ONCE AGAIN THIS EVENING...AS STRATUS
DECK SPREADS EAST AND MID LEVEL CLOUDS DEVELOP OVERNIGHT.

RODRIGUEZ

//PREV DISCUSSION...

254 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM CHANCES AND
TIMING THROUGH SUNDAY EVENING...HIGH TEMPS THIS WEEKEND AND THEN
MUCH COOLER TEMPS EARLY NEXT WEEK.

CONFIDENCE REGARDING CONVECTIVE TRENDS OVER THE NEXT 12 TO 18
HOURS IS FAIRLY LOW. A WEAK UPPER WAVE IS MOVING EAST/SOUTHEAST
ACROSS SOUTHERN WISCONSIN WHICH MAY ALLOW ISOLATED ACTIVITY TO
DEVELOP OVER THE NEXT FEW HOURS. ISOLATED ACTIVITY OVER WESTERN IL
APPEARS TO BE ON THE TRAILING EDGE OF THE WAVE PUSHING ACROSS
SOUTHERN IL BUT ALSO ALONG AN INSTABILITY AXIS EXTENDING INTO
EASTERN IA. SHORT TERM/HI RES GUIDANCE SUGGESTS JUST ISOLATED
COVERAGE THROUGH EARLY THIS EVENING THEN DRY THROUGH LATE EVENING
AND POSSIBLY INTO THE OVERNIGHT HOURS.

AS LOW LEVEL MOISTURE RETURNS TONIGHT ANOTHER WAVE CURRENTLY OVER
EASTERN SOUTH DAKOTA MAY AID THUNDERSTORM DEVELOPMENT OVERNIGHT
TOWARD SUNRISE AND PERHAPS OVER THE EASTERN CWA DEPENDING ON
WHEN...AND IF...ANYTHING DOES DEVELOP...THEN EXIT TO THE SOUTHEAST
QUICKLY SATURDAY MORNING. OPTED TO MAINTAIN LIKELY POPS FOR THIS
TIME PERIOD BUT THERE IS LITTLE CONTINUITY IN THE MODELS AND ITS
POSSIBLE MUCH OF THE OVERNIGHT COULD END UP DRY.

TRENDS BECOME A BIT MORE CONFIDENT ON SATURDAY AS THE NORTHERN CWA
REMAINS CAPPED BUT INSTABILITY ACROSS THE SOUTHERN CWA/CENTRAL IL
INCREASES BY LATE AFTERNOON FOR EXPECTED THUNDERSTORM DEVELOPMENT.
THE SEVERE THREAT WOULD BE PRIMARILY DAMAGING WINDS BUT WITH
DEWPOINTS SURGING BACK INTO THE 70S...HEAVY RAIN WILL BE POSSIBLE
AND WITH TRAINING OF STORMS OVER THE SAME AREAS...SOME POTENTIAL
FOR FLOODING WILL ALSO BE POSSIBLE. BULK OF THIS ACTIVITY APPEARS
TO REMAIN SOUTH OF THE I-80 CORRIDOR WITH THE ACTIVITY MOVING
SOUTHEAST OF THE CWA SATURDAY NIGHT.

HIGH TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON THUNDERSTORMS...
AND HOW SOON THEY FORM AS WELL AS CLOUD COVER. LOW LEVEL THERMAL
PROFILES WOULD SUGGEST UPPER 80S TO AROUND 90 IS DOABLE BUT MADE
NO CHANGES TO CURRENT FORECAST OF MID/UPPER 80S. WITH LITTLE
CHANGE TO AIRMASS SATURDAY NIGHT...AND LIKELY WET GROUND ACROSS
THE SOUTHERN CWA...COMBINED WITH LIGHT WINDS...FOG DEVELOPMENT
SEEMS LIKELY LATE SATURDAY NIGHT INTO SUNDAY MORNING...PRIMARILY
ACROSS THE SOUTHERN CWA.

LOW PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SUNDAY WITH A
TRAILING COLD FRONT MOVING ACROSS THE AREA SUNDAY MORNING. WINDS
WILL SHIFT WEST/NORTHWEST BEHIND THE FRONT AND FORECAST SOUNDINGS
SUGGEST IT WOULD BECOME QUITE BREEZY/WINDY SUNDAY AFTERNOON. ANY
THUNDERSTORM POTENTIAL WOULD LIKELY BE SHORT-LIVED AND ALONG/AHEAD
OF THE FRONT.

A SECOND COLD FRONT/SURGE OF COLDER AIR WILL THEN MOVE SOUTH
ACROSS THE WESTERN LAKES SUNDAY NIGHT. THIS COULD TRIGGER A FEW
SHOWERS OVERNIGHT BUT BULK OF THIS ACTIVITY SHOULD REMAIN
NORTHEAST OF THE CWA. WINDS WILL SHIFT NORTHERLY BEHIND THIS FRONT
WITH HIGHS ON MONDAY ONLY IN THE LOWER/MID 70S. TEMPS MODERATE
BACK INTO THE UPPER 70S/NEAR 80 BY THE MIDDLE OF NEXT WEEK WITH
PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS...MAINLY IN THE
AFTERNOON/EARLY EVENING. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR CIGS LIKELY AT TIMES THROUGH MID-MORNING.
* SMALL THREAT OF SHRA/TSRA THROUGH THIS MORNING.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE LATE THIS
  AFTERNOON.


//DISCUSSION...UPDATED 06Z...

A DIFFUSE LOW-LEVEL TROUGH FROM MN DOWN TO KS CONTINUES TO INCH
EASTWARD. MOISTURE CONTINUES TO SLOWLY INCREASE ACROSS THE AREA
AHEAD OF THIS. WITH THAT INCREASE...2000-3500 FT CIGS ARE
WIDESPREAD ACROSS NORTHERN IA/WI/NORTHERN IL AND EXPECTING THAT
OVER THE TAF SITES THROUGH AT LEAST DAYBREAK AND LIKELY A FEW
HOURS LONGER. THERE IS SOME INDICATION ROCKFORD COULD DROP DOWN TO
NEAR 1000 FT AROUND DAYBREAK. WARM AIR ADVECTION ASCENT MAY BE
ENOUGH PRIOR TO DAYBREAK TO SPARK A FEW SHRA/TSRA BUT MAINLY SOUTH
OF THE TAF SITES. CONVECTION EXPECTED PRIOR TO DAYBREAK ACROSS
PARTS OF SD INTO NW/NC IA IS EXPECTED TO WEAKEN THIS MORNING AS IT
SHIFTS EAST. SO WHILE CANNOT RULE OUT AND SHRA/TSRA TODAY...THE
FORCING IS PRETTY NEBULOUS DESPITE HIGH MOISTURE AROUND. SO HAVE
KEPT THE TAFS PRIMARILY DRY. THE BETTER FOCUS TONIGHT WILL BE
ALONG A WARM FRONT BOUNDARY DRAPED ACROSS CENTRAL IL AND IN.

WINDS ARE A CHALLENGE TODAY DUE PARTLY TO THE LIGHT GRADIENT AND
MORNING CLOUD COVER LIKELY TO INHIBIT MIXING TO SOME DEGREE. IT
WOULD APPEAR A LAKE BREEZE WILL DEVELOP BUT HOW FAR INLAND THIS
PROPAGATES IS THE MAIN UNCERTAINTY. HAVE OPTED TO INCLUDE IN THIS
SET OF TAFS BUT NOT MENTION A WIND SHIFT AT ORD UNTIL LATE IN THE
DAY/EARLY EVE...AS ANY LAKE BREEZE ARRIVAL WOULD LIKELY BE LATER.


//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH IN MVFR CIGS OCCURRING THROUGH AT LEAST 12Z AND MEDIUM IN
  BASES REMAINING ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA THROUGH THE DAY TODAY BUT ANY ARE LIKELY TO
  BE TEMPORARY.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY SHIFT WILL OCCUR AT BOTH AIRPORTS.


//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

MTF/IZZI

&&

.MARINE...
205 PM CDT

SOUTHERLY WINDS WILL CONTINUE TO STRENGTHEN OVER THE LAKE THIS
AFTERNOON AND TONIGHT AS HIGH PRESSURE MOVES OFF THE MID ATLANTIC
COAST WHILE LOW PRESSURE MOVES ACROSS THE MIDDLE AND UPPER
MISSISSIPPI VALLEY. THE SURFACE TROUGH LEADING TO THE INCREASE IN
WINDS WILL WEAKEN AND DISSIPATE SATURDAY. LOW PRESSURE DROPPING
OUT OF THE CANADIAN ROCKIES AND TRACKING ACROSS THE SOUTHERN
CANADIAN PRAIRIES WILL BECOME THE MORE DOMINANT FEATURE TO AFFECT
LAKE MICHIGAN AS IT TRACKS ACROSS LAKE SUPERIOR AND LAKE MICHIGAN
SATURDAY NIGHT. WINDS WILL BECOME WEAKER AND MORE VARIABLE WITH THE
LOW WEAKENING AS IT PASSES ACROSS THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT. A SURGE OF MUCH COOLER AIR WITH PUSH SOUTH DOWN
THE LENGTH OF THE LAKE SUNDAY NIGHT AND MONDAY WITH WINDS BECOMING
NORTHERLY AND INCREASING TO ARND 30KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT POSSIBLE. THE MOST LIKELY PERIOD TO SEE THE GALE
FORCE GUSTS SHOULD BE SATURDAY NIGHT INTO SUNDAY MORNING WHEN THE
COLD ADVECTION FOLLOWING THE PASSAGE OF THE LOW AND AN ASSOCIATED
COLD FRONT WILL BE THE STRONGEST. HIGH PRESSURE WILL QUICKLY BUILD
ACROSS THE PLAINS MONDAY AND SPREAD ACROSS THE UPPER MISSISSIPPI
VALLEY AND WESTERN GREAT LAKES MONDAY NIGHT AND THEN SETTLE INTO
THE OHIO VALLEY BY TUESDAY. ANOTHER WEAK LOW TRACKING
SOUTHEASTWARD ACROSS ONTARIO WILL KEEP GENERALLY NORTHWESTERLY TO
WESTERLY WINDS OVER THE LAKE INTO TUESDAY.

WHILE A GALE HEADLINE WILL NOT BE ISSUED WITH THE STRONG NORTH
WINDS SUNDAY NIGHT AND MONDAY...WINDS AND WAVES WILL LIKELY BE
SUFFICIENT TO NECESSITATE A SMALL CRAFT ADVISORY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 260546
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1246 AM CDT SAT JUL 26 2014

.DISCUSSION...
656 PM CDT

MAIN FORECAST UPDATES WERE TO REMOVE POPS THIS EVENING...AND THEN
SHIFT HIGHEST POPS TO THE SOUTHERN THIRD OF THE CWA AFTER MIDNIGHT
TONIGHT.

DEPARTING WAVE TO THE EAST THIS PAST AFTERNOON HAS ALLOWED FOR
DRIER CONDITIONS TO REMAIN IN PLACE EARLY THIS EVENING ACROSS ALL
OF NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH LATEST RADAR
MOSAIC SHOWING LITTLE OR NO PRECIP OVER THE ENTIRE REGION AT THIS
HOUR. WHILE WEAK FORCING ALOFT WILL REMAIN IN PLACE OWING TO WEAK
MID LEVEL IMPULSES APPROACHING FROM THE WEST A LACK OF SURFACE
FOCUS IN A HIGHLY CAPPED ENVIRONMENT...12-16C 700MB TEMPS PER RAP
ANALYSIS...WILL LIMIT ANY DEVELOPMENT THIS EVENING. OUTSIDE OF A
STRAY SPRINKLE OR LIGHT SHOWER...THIS EVENING WILL REMAIN MOSTLY
DRY AND SO HAVE DROPPED POPS DURING THIS PERIOD. WARM FRONT TO THE
SOUTHWEST WILL SLOWLY MOVE NORTH NORTHEAST OVERNIGHT WHILE
INCREASING LLJ AND WAA HELP DEVELOP SOME SHOWERS AND THUNDERSTORMS
AFTER MIDNIGHT. THE BULK OF THIS PRECIP WILL LIKELY REMAIN
CONFINED TO AREAS ALONG AND SOUTH OF INTERSTATE 80 AS IT SLIDES
EAST SOUTHEAST WITH THE VEERING LLJ...WITH THE STRONGEST STORMS
PRODUCING BRIEF HEAVY DOWNPOURS.

CURRENT CLEAR SKIES OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WILL QUICKLY BECOME CLOUDY ONCE AGAIN THIS EVENING...AS STRATUS
DECK SPREADS EAST AND MID LEVEL CLOUDS DEVELOP OVERNIGHT.

RODRIGUEZ

//PREV DISCUSSION...

254 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM CHANCES AND
TIMING THROUGH SUNDAY EVENING...HIGH TEMPS THIS WEEKEND AND THEN
MUCH COOLER TEMPS EARLY NEXT WEEK.

CONFIDENCE REGARDING CONVECTIVE TRENDS OVER THE NEXT 12 TO 18
HOURS IS FAIRLY LOW. A WEAK UPPER WAVE IS MOVING EAST/SOUTHEAST
ACROSS SOUTHERN WISCONSIN WHICH MAY ALLOW ISOLATED ACTIVITY TO
DEVELOP OVER THE NEXT FEW HOURS. ISOLATED ACTIVITY OVER WESTERN IL
APPEARS TO BE ON THE TRAILING EDGE OF THE WAVE PUSHING ACROSS
SOUTHERN IL BUT ALSO ALONG AN INSTABILITY AXIS EXTENDING INTO
EASTERN IA. SHORT TERM/HI RES GUIDANCE SUGGESTS JUST ISOLATED
COVERAGE THROUGH EARLY THIS EVENING THEN DRY THROUGH LATE EVENING
AND POSSIBLY INTO THE OVERNIGHT HOURS.

AS LOW LEVEL MOISTURE RETURNS TONIGHT ANOTHER WAVE CURRENTLY OVER
EASTERN SOUTH DAKOTA MAY AID THUNDERSTORM DEVELOPMENT OVERNIGHT
TOWARD SUNRISE AND PERHAPS OVER THE EASTERN CWA DEPENDING ON
WHEN...AND IF...ANYTHING DOES DEVELOP...THEN EXIT TO THE SOUTHEAST
QUICKLY SATURDAY MORNING. OPTED TO MAINTAIN LIKELY POPS FOR THIS
TIME PERIOD BUT THERE IS LITTLE CONTINUITY IN THE MODELS AND ITS
POSSIBLE MUCH OF THE OVERNIGHT COULD END UP DRY.

TRENDS BECOME A BIT MORE CONFIDENT ON SATURDAY AS THE NORTHERN CWA
REMAINS CAPPED BUT INSTABILITY ACROSS THE SOUTHERN CWA/CENTRAL IL
INCREASES BY LATE AFTERNOON FOR EXPECTED THUNDERSTORM DEVELOPMENT.
THE SEVERE THREAT WOULD BE PRIMARILY DAMAGING WINDS BUT WITH
DEWPOINTS SURGING BACK INTO THE 70S...HEAVY RAIN WILL BE POSSIBLE
AND WITH TRAINING OF STORMS OVER THE SAME AREAS...SOME POTENTIAL
FOR FLOODING WILL ALSO BE POSSIBLE. BULK OF THIS ACTIVITY APPEARS
TO REMAIN SOUTH OF THE I-80 CORRIDOR WITH THE ACTIVITY MOVING
SOUTHEAST OF THE CWA SATURDAY NIGHT.

HIGH TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON THUNDERSTORMS...
AND HOW SOON THEY FORM AS WELL AS CLOUD COVER. LOW LEVEL THERMAL
PROFILES WOULD SUGGEST UPPER 80S TO AROUND 90 IS DOABLE BUT MADE
NO CHANGES TO CURRENT FORECAST OF MID/UPPER 80S. WITH LITTLE
CHANGE TO AIRMASS SATURDAY NIGHT...AND LIKELY WET GROUND ACROSS
THE SOUTHERN CWA...COMBINED WITH LIGHT WINDS...FOG DEVELOPMENT
SEEMS LIKELY LATE SATURDAY NIGHT INTO SUNDAY MORNING...PRIMARILY
ACROSS THE SOUTHERN CWA.

LOW PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SUNDAY WITH A
TRAILING COLD FRONT MOVING ACROSS THE AREA SUNDAY MORNING. WINDS
WILL SHIFT WEST/NORTHWEST BEHIND THE FRONT AND FORECAST SOUNDINGS
SUGGEST IT WOULD BECOME QUITE BREEZY/WINDY SUNDAY AFTERNOON. ANY
THUNDERSTORM POTENTIAL WOULD LIKELY BE SHORT-LIVED AND ALONG/AHEAD
OF THE FRONT.

A SECOND COLD FRONT/SURGE OF COLDER AIR WILL THEN MOVE SOUTH
ACROSS THE WESTERN LAKES SUNDAY NIGHT. THIS COULD TRIGGER A FEW
SHOWERS OVERNIGHT BUT BULK OF THIS ACTIVITY SHOULD REMAIN
NORTHEAST OF THE CWA. WINDS WILL SHIFT NORTHERLY BEHIND THIS FRONT
WITH HIGHS ON MONDAY ONLY IN THE LOWER/MID 70S. TEMPS MODERATE
BACK INTO THE UPPER 70S/NEAR 80 BY THE MIDDLE OF NEXT WEEK WITH
PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS...MAINLY IN THE
AFTERNOON/EARLY EVENING. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* MVFR CIGS LIKELY AT TIMES THROUGH MID-MORNING.
* SMALL THREAT OF SHRA/TSRA THROUGH THIS MORNING.
* POSSIBLE WIND SHIFT TO EAST WITH A LAKE BREEZE LATE THIS
  AFTERNOON.


//DISCUSSION...UPDATED 06Z...

A DIFFUSE LOW-LEVEL TROUGH FROM MN DOWN TO KS CONTINUES TO INCH
EASTWARD. MOISTURE CONTINUES TO SLOWLY INCREASE ACROSS THE AREA
AHEAD OF THIS. WITH THAT INCREASE...2000-3500 FT CIGS ARE
WIDESPREAD ACROSS NORTHERN IA/WI/NORTHERN IL AND EXPECTING THAT
OVER THE TAF SITES THROUGH AT LEAST DAYBREAK AND LIKELY A FEW
HOURS LONGER. THERE IS SOME INDICATION ROCKFORD COULD DROP DOWN TO
NEAR 1000 FT AROUND DAYBREAK. WARM AIR ADVECTION ASCENT MAY BE
ENOUGH PRIOR TO DAYBREAK TO SPARK A FEW SHRA/TSRA BUT MAINLY SOUTH
OF THE TAF SITES. CONVECTION EXPECTED PRIOR TO DAYBREAK ACROSS
PARTS OF SD INTO NW/NC IA IS EXPECTED TO WEAKEN THIS MORNING AS IT
SHIFTS EAST. SO WHILE CANNOT RULE OUT AND SHRA/TSRA TODAY...THE
FORCING IS PRETTY NEBULOUS DESPITE HIGH MOISTURE AROUND. SO HAVE
KEPT THE TAFS PRIMARILY DRY. THE BETTER FOCUS TONIGHT WILL BE
ALONG A WARM FRONT BOUNDARY DRAPED ACROSS CENTRAL IL AND IN.

WINDS ARE A CHALLENGE TODAY DUE PARTLY TO THE LIGHT GRADIENT AND
MORNING CLOUD COVER LIKELY TO INHIBIT MIXING TO SOME DEGREE. IT
WOULD APPEAR A LAKE BREEZE WILL DEVELOP BUT HOW FAR INLAND THIS
PROPAGATES IS THE MAIN UNCERTAINTY. HAVE OPTED TO INCLUDE IN THIS
SET OF TAFS BUT NOT MENTION A WIND SHIFT AT ORD UNTIL LATE IN THE
DAY/EARLY EVE...AS ANY LAKE BREEZE ARRIVAL WOULD LIKELY BE LATER.


//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH IN MVFR CIGS OCCURRING THROUGH AT LEAST 12Z AND MEDIUM IN
  BASES REMAINING ABOVE 1500 FT.
* LOW IN ANY SHRA/TSRA THROUGH THE DAY TODAY BUT ANY ARE LIKELY TO
  BE TEMPORARY.
* LOW IN WIND DIRECTION THROUGH MUCH OF THE TAF INCLUDING WHETHER
  AN EASTERLY SHIFT WILL OCCUR AT BOTH AIRPORTS.


//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

MTF/IZZI

&&

.MARINE...
205 PM CDT

SOUTHERLY WINDS WILL CONTINUE TO STRENGTHEN OVER THE LAKE THIS
AFTERNOON AND TONIGHT AS HIGH PRESSURE MOVES OFF THE MID ATLANTIC
COAST WHILE LOW PRESSURE MOVES ACROSS THE MIDDLE AND UPPER
MISSISSIPPI VALLEY. THE SURFACE TROUGH LEADING TO THE INCREASE IN
WINDS WILL WEAKEN AND DISSIPATE SATURDAY. LOW PRESSURE DROPPING
OUT OF THE CANADIAN ROCKIES AND TRACKING ACROSS THE SOUTHERN
CANADIAN PRAIRIES WILL BECOME THE MORE DOMINANT FEATURE TO AFFECT
LAKE MICHIGAN AS IT TRACKS ACROSS LAKE SUPERIOR AND LAKE MICHIGAN
SATURDAY NIGHT. WINDS WILL BECOME WEAKER AND MORE VARIABLE WITH THE
LOW WEAKENING AS IT PASSES ACROSS THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT. A SURGE OF MUCH COOLER AIR WITH PUSH SOUTH DOWN
THE LENGTH OF THE LAKE SUNDAY NIGHT AND MONDAY WITH WINDS BECOMING
NORTHERLY AND INCREASING TO ARND 30KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT POSSIBLE. THE MOST LIKELY PERIOD TO SEE THE GALE
FORCE GUSTS SHOULD BE SATURDAY NIGHT INTO SUNDAY MORNING WHEN THE
COLD ADVECTION FOLLOWING THE PASSAGE OF THE LOW AND AN ASSOCIATED
COLD FRONT WILL BE THE STRONGEST. HIGH PRESSURE WILL QUICKLY BUILD
ACROSS THE PLAINS MONDAY AND SPREAD ACROSS THE UPPER MISSISSIPPI
VALLEY AND WESTERN GREAT LAKES MONDAY NIGHT AND THEN SETTLE INTO
THE OHIO VALLEY BY TUESDAY. ANOTHER WEAK LOW TRACKING
SOUTHEASTWARD ACROSS ONTARIO WILL KEEP GENERALLY NORTHWESTERLY TO
WESTERLY WINDS OVER THE LAKE INTO TUESDAY.

WHILE A GALE HEADLINE WILL NOT BE ISSUED WITH THE STRONG NORTH
WINDS SUNDAY NIGHT AND MONDAY...WINDS AND WAVES WILL LIKELY BE
SUFFICIENT TO NECESSITATE A SMALL CRAFT ADVISORY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 260255
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
955 PM CDT FRI JUL 25 2014

.DISCUSSION...
656 PM CDT

MAIN FORECAST UPDATES WERE TO REMOVE POPS THIS EVENING...AND THEN
SHIFT HIGHEST POPS TO THE SOUTHERN THIRD OF THE CWA AFTER MIDNIGHT
TONIGHT.

DEPARTING WAVE TO THE EAST THIS PAST AFTERNOON HAS ALLOWED FOR
DRIER CONDITIONS TO REMAIN IN PLACE EARLY THIS EVENING ACROSS ALL
OF NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH LATEST RADAR
MOSAIC SHOWING LITTLE OR NO PRECIP OVER THE ENTIRE REGION AT THIS
HOUR. WHILE WEAK FORCING ALOFT WILL REMAIN IN PLACE OWING TO WEAK
MID LEVEL IMPULSES APPROACHING FROM THE WEST A LACK OF SURFACE
FOCUS IN A HIGHLY CAPPED ENVIRONMENT...12-16C 700MB TEMPS PER RAP
ANALYSIS...WILL LIMIT ANY DEVELOPMENT THIS EVENING. OUTSIDE OF A
STRAY SPRINKLE OR LIGHT SHOWER...THIS EVENING WILL REMAIN MOSTLY
DRY AND SO HAVE DROPPED POPS DURING THIS PERIOD. WARM FRONT TO THE
SOUTHWEST WILL SLOWLY MOVE NORTH NORTHEAST OVERNIGHT WHILE
INCREASING LLJ AND WAA HELP DEVELOP SOME SHOWERS AND THUNDERSTORMS
AFTER MIDNIGHT. THE BULK OF THIS PRECIP WILL LIKELY REMAIN
CONFINED TO AREAS ALONG AND SOUTH OF INTERSTATE 80 AS IT SLIDES
EAST SOUTHEAST WITH THE VEERING LLJ...WITH THE STRONGEST STORMS
PRODUCING BRIEF HEAVY DOWNPOURS.

CURRENT CLEAR SKIES OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WILL QUICKLY BECOME CLOUDY ONCE AGAIN THIS EVENING...AS STRATUS
DECK SPREADS EAST AND MID LEVEL CLOUDS DEVELOP OVERNIGHT.

RODRIGUEZ

//PREV DISCUSSION...

254 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM CHANCES AND
TIMING THROUGH SUNDAY EVENING...HIGH TEMPS THIS WEEKEND AND THEN
MUCH COOLER TEMPS EARLY NEXT WEEK.

CONFIDENCE REGARDING CONVECTIVE TRENDS OVER THE NEXT 12 TO 18
HOURS IS FAIRLY LOW. A WEAK UPPER WAVE IS MOVING EAST/SOUTHEAST
ACROSS SOUTHERN WISCONSIN WHICH MAY ALLOW ISOLATED ACTIVITY TO
DEVELOP OVER THE NEXT FEW HOURS. ISOLATED ACTIVITY OVER WESTERN IL
APPEARS TO BE ON THE TRAILING EDGE OF THE WAVE PUSHING ACROSS
SOUTHERN IL BUT ALSO ALONG AN INSTABILITY AXIS EXTENDING INTO
EASTERN IA. SHORT TERM/HI RES GUIDANCE SUGGESTS JUST ISOLATED
COVERAGE THROUGH EARLY THIS EVENING THEN DRY THROUGH LATE EVENING
AND POSSIBLY INTO THE OVERNIGHT HOURS.

AS LOW LEVEL MOISTURE RETURNS TONIGHT ANOTHER WAVE CURRENTLY OVER
EASTERN SOUTH DAKOTA MAY AID THUNDERSTORM DEVELOPMENT OVERNIGHT
TOWARD SUNRISE AND PERHAPS OVER THE EASTERN CWA DEPENDING ON
WHEN...AND IF...ANYTHING DOES DEVELOP...THEN EXIT TO THE SOUTHEAST
QUICKLY SATURDAY MORNING. OPTED TO MAINTAIN LIKELY POPS FOR THIS
TIME PERIOD BUT THERE IS LITTLE CONTINUITY IN THE MODELS AND ITS
POSSIBLE MUCH OF THE OVERNIGHT COULD END UP DRY.

TRENDS BECOME A BIT MORE CONFIDENT ON SATURDAY AS THE NORTHERN CWA
REMAINS CAPPED BUT INSTABILITY ACROSS THE SOUTHERN CWA/CENTRAL IL
INCREASES BY LATE AFTERNOON FOR EXPECTED THUNDERSTORM DEVELOPMENT.
THE SEVERE THREAT WOULD BE PRIMARILY DAMAGING WINDS BUT WITH
DEWPOINTS SURGING BACK INTO THE 70S...HEAVY RAIN WILL BE POSSIBLE
AND WITH TRAINING OF STORMS OVER THE SAME AREAS...SOME POTENTIAL
FOR FLOODING WILL ALSO BE POSSIBLE. BULK OF THIS ACTIVITY APPEARS
TO REMAIN SOUTH OF THE I-80 CORRIDOR WITH THE ACTIVITY MOVING
SOUTHEAST OF THE CWA SATURDAY NIGHT.

HIGH TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON THUNDERSTORMS...
AND HOW SOON THEY FORM AS WELL AS CLOUD COVER. LOW LEVEL THERMAL
PROFILES WOULD SUGGEST UPPER 80S TO AROUND 90 IS DOABLE BUT MADE
NO CHANGES TO CURRENT FORECAST OF MID/UPPER 80S. WITH LITTLE
CHANGE TO AIRMASS SATURDAY NIGHT...AND LIKELY WET GROUND ACROSS
THE SOUTHERN CWA...COMBINED WITH LIGHT WINDS...FOG DEVELOPMENT
SEEMS LIKELY LATE SATURDAY NIGHT INTO SUNDAY MORNING...PRIMARILY
ACROSS THE SOUTHERN CWA.

LOW PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SUNDAY WITH A
TRAILING COLD FRONT MOVING ACROSS THE AREA SUNDAY MORNING. WINDS
WILL SHIFT WEST/NORTHWEST BEHIND THE FRONT AND FORECAST SOUNDINGS
SUGGEST IT WOULD BECOME QUITE BREEZY/WINDY SUNDAY AFTERNOON. ANY
THUNDERSTORM POTENTIAL WOULD LIKELY BE SHORT-LIVED AND ALONG/AHEAD
OF THE FRONT.

A SECOND COLD FRONT/SURGE OF COLDER AIR WILL THEN MOVE SOUTH
ACROSS THE WESTERN LAKES SUNDAY NIGHT. THIS COULD TRIGGER A FEW
SHOWERS OVERNIGHT BUT BULK OF THIS ACTIVITY SHOULD REMAIN
NORTHEAST OF THE CWA. WINDS WILL SHIFT NORTHERLY BEHIND THIS FRONT
WITH HIGHS ON MONDAY ONLY IN THE LOWER/MID 70S. TEMPS MODERATE
BACK INTO THE UPPER 70S/NEAR 80 BY THE MIDDLE OF NEXT WEEK WITH
PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS...MAINLY IN THE
AFTERNOON/EARLY EVENING. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 03Z...

* MVFR CIGS PROBABLY DEVELOPING TONIGHT
* SMALL THREAT OF SHRA/POSSIBLE TSRA LATE TONIGHT/EARLY SATURDAY
  MORNING
* WIND SHIFT TO EAST WITH LAKE BREEZE POSSIBLE SATURDAY AFTERNOON

IZZI

//DISCUSSION...UPDATED 00Z...

UPPER LEVEL DISTURBANCE PUSHING SOUTHEAST OF THE REGION SHOULD
ALLOW FOR GENERALLY DRY CONDITIONS THROUGH THE EVENING INTO THE
START OVER THE OVERNIGHT HOURS. INCREASING MOISTURE SURGING INTO
THE REGION LATE TONIGHT INTO EARLY SATURDAY COULD RESULT IN SCTD
SHRA/TSRA DEVELOPING WITH LATEST MODEL GUIDANCE SUGGESTING THE
BEST CHANCES WILL BE SOUTH OF CHICAGO AND ROCKFORD.

WINDS HAVE BEEN BACKING TO THE SOUTH AND EVEN SOUTHEAST OVER NW IL
AND IA AS DEVELOPING WARM FRONT TAKES SHAPE. ANTICIPATE THIS TREND
TO CONTINUE EAST INTO CHGO TERMINALS THIS EVENING WITH WINDS
PROBABLY BECOMING MORE SOUTHERLY AND POSSIBLY EVEN A BIT EAST OF
DUE SOUTH...THOUGH SPEEDS EXPECTED TO BE LIGHT. VERY LOW
CONFIDENCE IN WIND DIRECTION TOMORROW THOUGH SOME SORT OF WESTERLY
COMPONENT SEEMS PROBABLE...HOWEVER AM CONCERNED THAT SPEEDS COULD
BE LIGHT ENOUGH TO ALLOW LAKE BREEZE TO FORM.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 03Z...

* MEDIUM CONFIDENCE IN CIGS FORECAST THROUGH PERIOD
* MEDIUM CONFIDENCE IN TERMINALS REMAINING DRY THROUGH PERIOD
* LOW CONFIDENCE IN WIND DIRECTION SATURDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

IZZI

&&

.MARINE...
205 PM CDT

SOUTHERLY WINDS WILL CONTINUE TO STRENGTHEN OVER THE LAKE THIS
AFTERNOON AND TONIGHT AS HIGH PRESSURE MOVES OFF THE MID ATLANTIC
COAST WHILE LOW PRESSURE MOVES ACROSS THE MIDDLE AND UPPER
MISSISSIPPI VALLEY. THE SURFACE TROUGH LEADING TO THE INCREASE IN
WINDS WILL WEAKEN AND DISSIPATE SATURDAY. LOW PRESSURE DROPPING
OUT OF THE CANADIAN ROCKIES AND TRACKING ACROSS THE SOUTHERN
CANADIAN PRAIRIES WILL BECOME THE MORE DOMINANT FEATURE TO AFFECT
LAKE MICHIGAN AS IT TRACKS ACROSS LAKE SUPERIOR AND LAKE MICHIGAN
SATURDAY NIGHT. WINDS WILL BECOME WEAKER AND MORE VARIABLE WITH THE
LOW WEAKENING AS IT PASSES ACROSS THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT. A SURGE OF MUCH COOLER AIR WITH PUSH SOUTH DOWN
THE LENGTH OF THE LAKE SUNDAY NIGHT AND MONDAY WITH WINDS BECOMING
NORTHERLY AND INCREASING TO ARND 30KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT POSSIBLE. THE MOST LIKELY PERIOD TO SEE THE GALE
FORCE GUSTS SHOULD BE SATURDAY NIGHT INTO SUNDAY MORNING WHEN THE
COLD ADVECTION FOLLOWING THE PASSAGE OF THE LOW AND AN ASSOCIATED
COLD FRONT WILL BE THE STRONGEST. HIGH PRESSURE WILL QUICKLY BUILD
ACROSS THE PLAINS MONDAY AND SPREAD ACROSS THE UPPER MISSISSIPPI
VALLEY AND WESTERN GREAT LAKES MONDAY NIGHT AND THEN SETTLE INTO
THE OHIO VALLEY BY TUESDAY. ANOTHER WEAK LOW TRACKING
SOUTHEASTWARD ACROSS ONTARIO WILL KEEP GENERALLY NORTHWESTERLY TO
WESTERLY WINDS OVER THE LAKE INTO TUESDAY.

WHILE A GALE HEADLINE WILL NOT BE ISSUED WITH THE STRONG NORTH
WINDS SUNDAY NIGHT AND MONDAY...WINDS AND WAVES WILL LIKELY BE
SUFFICIENT TO NECESSITATE A SMALL CRAFT ADVISORY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 260255
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
955 PM CDT FRI JUL 25 2014

.DISCUSSION...
656 PM CDT

MAIN FORECAST UPDATES WERE TO REMOVE POPS THIS EVENING...AND THEN
SHIFT HIGHEST POPS TO THE SOUTHERN THIRD OF THE CWA AFTER MIDNIGHT
TONIGHT.

DEPARTING WAVE TO THE EAST THIS PAST AFTERNOON HAS ALLOWED FOR
DRIER CONDITIONS TO REMAIN IN PLACE EARLY THIS EVENING ACROSS ALL
OF NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH LATEST RADAR
MOSAIC SHOWING LITTLE OR NO PRECIP OVER THE ENTIRE REGION AT THIS
HOUR. WHILE WEAK FORCING ALOFT WILL REMAIN IN PLACE OWING TO WEAK
MID LEVEL IMPULSES APPROACHING FROM THE WEST A LACK OF SURFACE
FOCUS IN A HIGHLY CAPPED ENVIRONMENT...12-16C 700MB TEMPS PER RAP
ANALYSIS...WILL LIMIT ANY DEVELOPMENT THIS EVENING. OUTSIDE OF A
STRAY SPRINKLE OR LIGHT SHOWER...THIS EVENING WILL REMAIN MOSTLY
DRY AND SO HAVE DROPPED POPS DURING THIS PERIOD. WARM FRONT TO THE
SOUTHWEST WILL SLOWLY MOVE NORTH NORTHEAST OVERNIGHT WHILE
INCREASING LLJ AND WAA HELP DEVELOP SOME SHOWERS AND THUNDERSTORMS
AFTER MIDNIGHT. THE BULK OF THIS PRECIP WILL LIKELY REMAIN
CONFINED TO AREAS ALONG AND SOUTH OF INTERSTATE 80 AS IT SLIDES
EAST SOUTHEAST WITH THE VEERING LLJ...WITH THE STRONGEST STORMS
PRODUCING BRIEF HEAVY DOWNPOURS.

CURRENT CLEAR SKIES OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WILL QUICKLY BECOME CLOUDY ONCE AGAIN THIS EVENING...AS STRATUS
DECK SPREADS EAST AND MID LEVEL CLOUDS DEVELOP OVERNIGHT.

RODRIGUEZ

//PREV DISCUSSION...

254 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM CHANCES AND
TIMING THROUGH SUNDAY EVENING...HIGH TEMPS THIS WEEKEND AND THEN
MUCH COOLER TEMPS EARLY NEXT WEEK.

CONFIDENCE REGARDING CONVECTIVE TRENDS OVER THE NEXT 12 TO 18
HOURS IS FAIRLY LOW. A WEAK UPPER WAVE IS MOVING EAST/SOUTHEAST
ACROSS SOUTHERN WISCONSIN WHICH MAY ALLOW ISOLATED ACTIVITY TO
DEVELOP OVER THE NEXT FEW HOURS. ISOLATED ACTIVITY OVER WESTERN IL
APPEARS TO BE ON THE TRAILING EDGE OF THE WAVE PUSHING ACROSS
SOUTHERN IL BUT ALSO ALONG AN INSTABILITY AXIS EXTENDING INTO
EASTERN IA. SHORT TERM/HI RES GUIDANCE SUGGESTS JUST ISOLATED
COVERAGE THROUGH EARLY THIS EVENING THEN DRY THROUGH LATE EVENING
AND POSSIBLY INTO THE OVERNIGHT HOURS.

AS LOW LEVEL MOISTURE RETURNS TONIGHT ANOTHER WAVE CURRENTLY OVER
EASTERN SOUTH DAKOTA MAY AID THUNDERSTORM DEVELOPMENT OVERNIGHT
TOWARD SUNRISE AND PERHAPS OVER THE EASTERN CWA DEPENDING ON
WHEN...AND IF...ANYTHING DOES DEVELOP...THEN EXIT TO THE SOUTHEAST
QUICKLY SATURDAY MORNING. OPTED TO MAINTAIN LIKELY POPS FOR THIS
TIME PERIOD BUT THERE IS LITTLE CONTINUITY IN THE MODELS AND ITS
POSSIBLE MUCH OF THE OVERNIGHT COULD END UP DRY.

TRENDS BECOME A BIT MORE CONFIDENT ON SATURDAY AS THE NORTHERN CWA
REMAINS CAPPED BUT INSTABILITY ACROSS THE SOUTHERN CWA/CENTRAL IL
INCREASES BY LATE AFTERNOON FOR EXPECTED THUNDERSTORM DEVELOPMENT.
THE SEVERE THREAT WOULD BE PRIMARILY DAMAGING WINDS BUT WITH
DEWPOINTS SURGING BACK INTO THE 70S...HEAVY RAIN WILL BE POSSIBLE
AND WITH TRAINING OF STORMS OVER THE SAME AREAS...SOME POTENTIAL
FOR FLOODING WILL ALSO BE POSSIBLE. BULK OF THIS ACTIVITY APPEARS
TO REMAIN SOUTH OF THE I-80 CORRIDOR WITH THE ACTIVITY MOVING
SOUTHEAST OF THE CWA SATURDAY NIGHT.

HIGH TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON THUNDERSTORMS...
AND HOW SOON THEY FORM AS WELL AS CLOUD COVER. LOW LEVEL THERMAL
PROFILES WOULD SUGGEST UPPER 80S TO AROUND 90 IS DOABLE BUT MADE
NO CHANGES TO CURRENT FORECAST OF MID/UPPER 80S. WITH LITTLE
CHANGE TO AIRMASS SATURDAY NIGHT...AND LIKELY WET GROUND ACROSS
THE SOUTHERN CWA...COMBINED WITH LIGHT WINDS...FOG DEVELOPMENT
SEEMS LIKELY LATE SATURDAY NIGHT INTO SUNDAY MORNING...PRIMARILY
ACROSS THE SOUTHERN CWA.

LOW PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SUNDAY WITH A
TRAILING COLD FRONT MOVING ACROSS THE AREA SUNDAY MORNING. WINDS
WILL SHIFT WEST/NORTHWEST BEHIND THE FRONT AND FORECAST SOUNDINGS
SUGGEST IT WOULD BECOME QUITE BREEZY/WINDY SUNDAY AFTERNOON. ANY
THUNDERSTORM POTENTIAL WOULD LIKELY BE SHORT-LIVED AND ALONG/AHEAD
OF THE FRONT.

A SECOND COLD FRONT/SURGE OF COLDER AIR WILL THEN MOVE SOUTH
ACROSS THE WESTERN LAKES SUNDAY NIGHT. THIS COULD TRIGGER A FEW
SHOWERS OVERNIGHT BUT BULK OF THIS ACTIVITY SHOULD REMAIN
NORTHEAST OF THE CWA. WINDS WILL SHIFT NORTHERLY BEHIND THIS FRONT
WITH HIGHS ON MONDAY ONLY IN THE LOWER/MID 70S. TEMPS MODERATE
BACK INTO THE UPPER 70S/NEAR 80 BY THE MIDDLE OF NEXT WEEK WITH
PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS...MAINLY IN THE
AFTERNOON/EARLY EVENING. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 03Z...

* MVFR CIGS PROBABLY DEVELOPING TONIGHT
* SMALL THREAT OF SHRA/POSSIBLE TSRA LATE TONIGHT/EARLY SATURDAY
  MORNING
* WIND SHIFT TO EAST WITH LAKE BREEZE POSSIBLE SATURDAY AFTERNOON

IZZI

//DISCUSSION...UPDATED 00Z...

UPPER LEVEL DISTURBANCE PUSHING SOUTHEAST OF THE REGION SHOULD
ALLOW FOR GENERALLY DRY CONDITIONS THROUGH THE EVENING INTO THE
START OVER THE OVERNIGHT HOURS. INCREASING MOISTURE SURGING INTO
THE REGION LATE TONIGHT INTO EARLY SATURDAY COULD RESULT IN SCTD
SHRA/TSRA DEVELOPING WITH LATEST MODEL GUIDANCE SUGGESTING THE
BEST CHANCES WILL BE SOUTH OF CHICAGO AND ROCKFORD.

WINDS HAVE BEEN BACKING TO THE SOUTH AND EVEN SOUTHEAST OVER NW IL
AND IA AS DEVELOPING WARM FRONT TAKES SHAPE. ANTICIPATE THIS TREND
TO CONTINUE EAST INTO CHGO TERMINALS THIS EVENING WITH WINDS
PROBABLY BECOMING MORE SOUTHERLY AND POSSIBLY EVEN A BIT EAST OF
DUE SOUTH...THOUGH SPEEDS EXPECTED TO BE LIGHT. VERY LOW
CONFIDENCE IN WIND DIRECTION TOMORROW THOUGH SOME SORT OF WESTERLY
COMPONENT SEEMS PROBABLE...HOWEVER AM CONCERNED THAT SPEEDS COULD
BE LIGHT ENOUGH TO ALLOW LAKE BREEZE TO FORM.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 03Z...

* MEDIUM CONFIDENCE IN CIGS FORECAST THROUGH PERIOD
* MEDIUM CONFIDENCE IN TERMINALS REMAINING DRY THROUGH PERIOD
* LOW CONFIDENCE IN WIND DIRECTION SATURDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

IZZI

&&

.MARINE...
205 PM CDT

SOUTHERLY WINDS WILL CONTINUE TO STRENGTHEN OVER THE LAKE THIS
AFTERNOON AND TONIGHT AS HIGH PRESSURE MOVES OFF THE MID ATLANTIC
COAST WHILE LOW PRESSURE MOVES ACROSS THE MIDDLE AND UPPER
MISSISSIPPI VALLEY. THE SURFACE TROUGH LEADING TO THE INCREASE IN
WINDS WILL WEAKEN AND DISSIPATE SATURDAY. LOW PRESSURE DROPPING
OUT OF THE CANADIAN ROCKIES AND TRACKING ACROSS THE SOUTHERN
CANADIAN PRAIRIES WILL BECOME THE MORE DOMINANT FEATURE TO AFFECT
LAKE MICHIGAN AS IT TRACKS ACROSS LAKE SUPERIOR AND LAKE MICHIGAN
SATURDAY NIGHT. WINDS WILL BECOME WEAKER AND MORE VARIABLE WITH THE
LOW WEAKENING AS IT PASSES ACROSS THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT. A SURGE OF MUCH COOLER AIR WITH PUSH SOUTH DOWN
THE LENGTH OF THE LAKE SUNDAY NIGHT AND MONDAY WITH WINDS BECOMING
NORTHERLY AND INCREASING TO ARND 30KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT POSSIBLE. THE MOST LIKELY PERIOD TO SEE THE GALE
FORCE GUSTS SHOULD BE SATURDAY NIGHT INTO SUNDAY MORNING WHEN THE
COLD ADVECTION FOLLOWING THE PASSAGE OF THE LOW AND AN ASSOCIATED
COLD FRONT WILL BE THE STRONGEST. HIGH PRESSURE WILL QUICKLY BUILD
ACROSS THE PLAINS MONDAY AND SPREAD ACROSS THE UPPER MISSISSIPPI
VALLEY AND WESTERN GREAT LAKES MONDAY NIGHT AND THEN SETTLE INTO
THE OHIO VALLEY BY TUESDAY. ANOTHER WEAK LOW TRACKING
SOUTHEASTWARD ACROSS ONTARIO WILL KEEP GENERALLY NORTHWESTERLY TO
WESTERLY WINDS OVER THE LAKE INTO TUESDAY.

WHILE A GALE HEADLINE WILL NOT BE ISSUED WITH THE STRONG NORTH
WINDS SUNDAY NIGHT AND MONDAY...WINDS AND WAVES WILL LIKELY BE
SUFFICIENT TO NECESSITATE A SMALL CRAFT ADVISORY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 260012
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
712 PM CDT FRI JUL 25 2014

.DISCUSSION...
656 PM CDT

MAIN FORECAST UPDATES WERE TO REMOVE POPS THIS EVENING...AND THEN
SHIFT HIGHEST POPS TO THE SOUTHERN THIRD OF THE CWA AFTER MIDNIGHT
TONIGHT.

DEPARTING WAVE TO THE EAST THIS PAST AFTERNOON HAS ALLOWED FOR
DRIER CONDITIONS TO REMAIN IN PLACE EARLY THIS EVENING ACROSS ALL
OF NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH LATEST RADAR
MOSAIC SHOWING LITTLE OR NO PRECIP OVER THE ENTIRE REGION AT THIS
HOUR. WHILE WEAK FORCING ALOFT WILL REMAIN IN PLACE OWING TO WEAK
MID LEVEL IMPULSES APPROACHING FROM THE WEST A LACK OF SURFACE
FOCUS IN A HIGHLY CAPPED ENVIRONMENT...12-16C 700MB TEMPS PER RAP
ANALYSIS...WILL LIMIT ANY DEVELOPMENT THIS EVENING. OUTSIDE OF A
STRAY SPRINKLE OR LIGHT SHOWER...THIS EVENING WILL REMAIN MOSTLY
DRY AND SO HAVE DROPPED POPS DURING THIS PERIOD. WARM FRONT TO THE
SOUTHWEST WILL SLOWLY MOVE NORTH NORTHEAST OVERNIGHT WHILE
INCREASING LLJ AND WAA HELP DEVELOP SOME SHOWERS AND THUNDERSTORMS
AFTER MIDNIGHT. THE BULK OF THIS PRECIP WILL LIKELY REMAIN
CONFINED TO AREAS ALONG AND SOUTH OF INTERSTATE 80 AS IT SLIDES
EAST SOUTHEAST WITH THE VEERING LLJ...WITH THE STRONGEST STORMS
PRODUCING BRIEF HEAVY DOWNPOURS.

CURRENT CLEAR SKIES OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WILL QUICKLY BECOME CLOUDY ONCE AGAIN THIS EVENING...AS STRATUS
DECK SPREADS EAST AND MID LEVEL CLOUDS DEVELOP OVERNIGHT.

RODRIGUEZ

&&

.PREV DISCUSSION...

254 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM CHANCES AND
TIMING THROUGH SUNDAY EVENING...HIGH TEMPS THIS WEEKEND AND THEN
MUCH COOLER TEMPS EARLY NEXT WEEK.

CONFIDENCE REGARDING CONVECTIVE TRENDS OVER THE NEXT 12 TO 18
HOURS IS FAIRLY LOW. A WEAK UPPER WAVE IS MOVING EAST/SOUTHEAST
ACROSS SOUTHERN WISCONSIN WHICH MAY ALLOW ISOLATED ACTIVITY TO
DEVELOP OVER THE NEXT FEW HOURS. ISOLATED ACTIVITY OVER WESTERN IL
APPEARS TO BE ON THE TRAILING EDGE OF THE WAVE PUSHING ACROSS
SOUTHERN IL BUT ALSO ALONG AN INSTABILITY AXIS EXTENDING INTO
EASTERN IA. SHORT TERM/HI RES GUIDANCE SUGGESTS JUST ISOLATED
COVERAGE THROUGH EARLY THIS EVENING THEN DRY THROUGH LATE EVENING
AND POSSIBLY INTO THE OVERNIGHT HOURS.

AS LOW LEVEL MOISTURE RETURNS TONIGHT ANOTHER WAVE CURRENTLY OVER
EASTERN SOUTH DAKOTA MAY AID THUNDERSTORM DEVELOPMENT OVERNIGHT
TOWARD SUNRISE AND PERHAPS OVER THE EASTERN CWA DEPENDING ON
WHEN...AND IF...ANYTHING DOES DEVELOP...THEN EXIT TO THE SOUTHEAST
QUICKLY SATURDAY MORNING. OPTED TO MAINTAIN LIKELY POPS FOR THIS
TIME PERIOD BUT THERE IS LITTLE CONTINUITY IN THE MODELS AND ITS
POSSIBLE MUCH OF THE OVERNIGHT COULD END UP DRY.

TRENDS BECOME A BIT MORE CONFIDENT ON SATURDAY AS THE NORTHERN CWA
REMAINS CAPPED BUT INSTABILITY ACROSS THE SOUTHERN CWA/CENTRAL IL
INCREASES BY LATE AFTERNOON FOR EXPECTED THUNDERSTORM DEVELOPMENT.
THE SEVERE THREAT WOULD BE PRIMARILY DAMAGING WINDS BUT WITH
DEWPOINTS SURGING BACK INTO THE 70S...HEAVY RAIN WILL BE POSSIBLE
AND WITH TRAINING OF STORMS OVER THE SAME AREAS...SOME POTENTIAL
FOR FLOODING WILL ALSO BE POSSIBLE. BULK OF THIS ACTIVITY APPEARS
TO REMAIN SOUTH OF THE I-80 CORRIDOR WITH THE ACTIVITY MOVING
SOUTHEAST OF THE CWA SATURDAY NIGHT.

HIGH TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON THUNDERSTORMS...
AND HOW SOON THEY FORM AS WELL AS CLOUD COVER. LOW LEVEL THERMAL
PROFILES WOULD SUGGEST UPPER 80S TO AROUND 90 IS DOABLE BUT MADE
NO CHANGES TO CURRENT FORECAST OF MID/UPPER 80S. WITH LITTLE
CHANGE TO AIRMASS SATURDAY NIGHT...AND LIKELY WET GROUND ACROSS
THE SOUTHERN CWA...COMBINED WITH LIGHT WINDS...FOG DEVELOPMENT
SEEMS LIKELY LATE SATURDAY NIGHT INTO SUNDAY MORNING...PRIMARILY
ACROSS THE SOUTHERN CWA.

LOW PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SUNDAY WITH A
TRAILING COLD FRONT MOVING ACROSS THE AREA SUNDAY MORNING. WINDS
WILL SHIFT WEST/NORTHWEST BEHIND THE FRONT AND FORECAST SOUNDINGS
SUGGEST IT WOULD BECOME QUITE BREEZY/WINDY SUNDAY AFTERNOON. ANY
THUNDERSTORM POTENTIAL WOULD LIKELY BE SHORT-LIVED AND ALONG/AHEAD
OF THE FRONT.

A SECOND COLD FRONT/SURGE OF COLDER AIR WILL THEN MOVE SOUTH
ACROSS THE WESTERN LAKES SUNDAY NIGHT. THIS COULD TRIGGER A FEW
SHOWERS OVERNIGHT BUT BULK OF THIS ACTIVITY SHOULD REMAIN
NORTHEAST OF THE CWA. WINDS WILL SHIFT NORTHERLY BEHIND THIS FRONT
WITH HIGHS ON MONDAY ONLY IN THE LOWER/MID 70S. TEMPS MODERATE
BACK INTO THE UPPER 70S/NEAR 80 BY THE MIDDLE OF NEXT WEEK WITH
PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS...MAINLY IN THE
AFTERNOON/EARLY EVENING. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* MVFR CIGS LIKELY TO ARRIVE THIS EVENING
* SMALL THREAT OF SHRA/POSSIBLE TSRA LATE TONIGHT/EARLY SATURDAY
  MORNING

IZZI

//DISCUSSION...UPDATED 00Z...

UPPER LEVEL DISTURBANCE PUSHING SOUTHEAST OF THE REGION SHOULD
ALLOW FOR GENERALLY DRY CONDITIONS THROUGH THE EVENING INTO THE
START OVER THE OVERNIGHT HOURS. INCREASING MOISTURE SURGING INTO
THE REGION LATE TONIGHT INTO EARLY SATURDAY COULD RESULT IN SCTD
SHRA/TSRA DEVELOPING WITH LATEST MODEL GUIDANCE SUGGESTING THE
BEST CHANCES WILL BE SOUTH OF CHICAGO AND ROCKFORD.

WINDS HAVE BEEN BACKING TO THE SOUTH AND EVEN SOUTHEAST OVER NW IL
AND IA AS DEVELOPING WARM FRONT TAKES SHAPE. ANTICIPATE THIS TREND
TO CONTINUE EAST INTO CHGO TERMINALS THIS EVENING WITH WINDS
PROBABLY BECOMING MORE SOUTHERLY AND POSSIBLY EVEN A BIT EAST OF
DUE SOUTH...THOUGH SPEEDS EXPECTED TO BE LIGHT. VERY LOW
CONFIDENCE IN WIND DIRECTION TOMORROW THOUGH SOME SORT OF WESTERLY
COMPONENT SEEMS PROBABLE...HOWEVER AM CONCERNED THAT SPEEDS COULD
BE LIGHT ENOUGH TO ALLOW LAKE BREEZE TO FORM.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM CONFIDENCE IN CIGS FORECAST THROUGH PERIOD
* MEDIUM CONFIDENCE IN TERMINALS REMAINING DRY THROUGH PERIOD
* LOW CONFIDENCE IN WIND DIRECTION SATURDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

IZZI

&&

.MARINE...
205 PM CDT

SOUTHERLY WINDS WILL CONTINUE TO STRENGTHEN OVER THE LAKE THIS
AFTERNOON AND TONIGHT AS HIGH PRESSURE MOVES OFF THE MID ATLANTIC
COAST WHILE LOW PRESSURE MOVES ACROSS THE MIDDLE AND UPPER
MISSISSIPPI VALLEY. THE SURFACE TROUGH LEADING TO THE INCREASE IN
WINDS WILL WEAKEN AND DISSIPATE SATURDAY. LOW PRESSURE DROPPING
OUT OF THE CANADIAN ROCKIES AND TRACKING ACROSS THE SOUTHERN
CANADIAN PRAIRIES WILL BECOME THE MORE DOMINANT FEATURE TO AFFECT
LAKE MICHIGAN AS IT TRACKS ACROSS LAKE SUPERIOR AND LAKE MICHIGAN
SATURDAY NIGHT. WINDS WILL BECOME WEAKER AND MORE VARIABLE WITH THE
LOW WEAKENING AS IT PASSES ACROSS THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT. A SURGE OF MUCH COOLER AIR WITH PUSH SOUTH DOWN
THE LENGTH OF THE LAKE SUNDAY NIGHT AND MONDAY WITH WINDS BECOMING
NORTHERLY AND INCREASING TO ARND 30KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT POSSIBLE. THE MOST LIKELY PERIOD TO SEE THE GALE
FORCE GUSTS SHOULD BE SATURDAY NIGHT INTO SUNDAY MORNING WHEN THE
COLD ADVECTION FOLLOWING THE PASSAGE OF THE LOW AND AN ASSOCIATED
COLD FRONT WILL BE THE STRONGEST. HIGH PRESSURE WILL QUICKLY BUILD
ACROSS THE PLAINS MONDAY AND SPREAD ACROSS THE UPPER MISSISSIPPI
VALLEY AND WESTERN GREAT LAKES MONDAY NIGHT AND THEN SETTLE INTO
THE OHIO VALLEY BY TUESDAY. ANOTHER WEAK LOW TRACKING
SOUTHEASTWARD ACROSS ONTARIO WILL KEEP GENERALLY NORTHWESTERLY TO
WESTERLY WINDS OVER THE LAKE INTO TUESDAY.

WHILE A GALE HEADLINE WILL NOT BE ISSUED WITH THE STRONG NORTH
WINDS SUNDAY NIGHT AND MONDAY...WINDS AND WAVES WILL LIKELY BE
SUFFICIENT TO NECESSITATE A SMALL CRAFT ADVISORY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 260012
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
712 PM CDT FRI JUL 25 2014

.DISCUSSION...
656 PM CDT

MAIN FORECAST UPDATES WERE TO REMOVE POPS THIS EVENING...AND THEN
SHIFT HIGHEST POPS TO THE SOUTHERN THIRD OF THE CWA AFTER MIDNIGHT
TONIGHT.

DEPARTING WAVE TO THE EAST THIS PAST AFTERNOON HAS ALLOWED FOR
DRIER CONDITIONS TO REMAIN IN PLACE EARLY THIS EVENING ACROSS ALL
OF NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH LATEST RADAR
MOSAIC SHOWING LITTLE OR NO PRECIP OVER THE ENTIRE REGION AT THIS
HOUR. WHILE WEAK FORCING ALOFT WILL REMAIN IN PLACE OWING TO WEAK
MID LEVEL IMPULSES APPROACHING FROM THE WEST A LACK OF SURFACE
FOCUS IN A HIGHLY CAPPED ENVIRONMENT...12-16C 700MB TEMPS PER RAP
ANALYSIS...WILL LIMIT ANY DEVELOPMENT THIS EVENING. OUTSIDE OF A
STRAY SPRINKLE OR LIGHT SHOWER...THIS EVENING WILL REMAIN MOSTLY
DRY AND SO HAVE DROPPED POPS DURING THIS PERIOD. WARM FRONT TO THE
SOUTHWEST WILL SLOWLY MOVE NORTH NORTHEAST OVERNIGHT WHILE
INCREASING LLJ AND WAA HELP DEVELOP SOME SHOWERS AND THUNDERSTORMS
AFTER MIDNIGHT. THE BULK OF THIS PRECIP WILL LIKELY REMAIN
CONFINED TO AREAS ALONG AND SOUTH OF INTERSTATE 80 AS IT SLIDES
EAST SOUTHEAST WITH THE VEERING LLJ...WITH THE STRONGEST STORMS
PRODUCING BRIEF HEAVY DOWNPOURS.

CURRENT CLEAR SKIES OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WILL QUICKLY BECOME CLOUDY ONCE AGAIN THIS EVENING...AS STRATUS
DECK SPREADS EAST AND MID LEVEL CLOUDS DEVELOP OVERNIGHT.

RODRIGUEZ

&&

.PREV DISCUSSION...

254 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM CHANCES AND
TIMING THROUGH SUNDAY EVENING...HIGH TEMPS THIS WEEKEND AND THEN
MUCH COOLER TEMPS EARLY NEXT WEEK.

CONFIDENCE REGARDING CONVECTIVE TRENDS OVER THE NEXT 12 TO 18
HOURS IS FAIRLY LOW. A WEAK UPPER WAVE IS MOVING EAST/SOUTHEAST
ACROSS SOUTHERN WISCONSIN WHICH MAY ALLOW ISOLATED ACTIVITY TO
DEVELOP OVER THE NEXT FEW HOURS. ISOLATED ACTIVITY OVER WESTERN IL
APPEARS TO BE ON THE TRAILING EDGE OF THE WAVE PUSHING ACROSS
SOUTHERN IL BUT ALSO ALONG AN INSTABILITY AXIS EXTENDING INTO
EASTERN IA. SHORT TERM/HI RES GUIDANCE SUGGESTS JUST ISOLATED
COVERAGE THROUGH EARLY THIS EVENING THEN DRY THROUGH LATE EVENING
AND POSSIBLY INTO THE OVERNIGHT HOURS.

AS LOW LEVEL MOISTURE RETURNS TONIGHT ANOTHER WAVE CURRENTLY OVER
EASTERN SOUTH DAKOTA MAY AID THUNDERSTORM DEVELOPMENT OVERNIGHT
TOWARD SUNRISE AND PERHAPS OVER THE EASTERN CWA DEPENDING ON
WHEN...AND IF...ANYTHING DOES DEVELOP...THEN EXIT TO THE SOUTHEAST
QUICKLY SATURDAY MORNING. OPTED TO MAINTAIN LIKELY POPS FOR THIS
TIME PERIOD BUT THERE IS LITTLE CONTINUITY IN THE MODELS AND ITS
POSSIBLE MUCH OF THE OVERNIGHT COULD END UP DRY.

TRENDS BECOME A BIT MORE CONFIDENT ON SATURDAY AS THE NORTHERN CWA
REMAINS CAPPED BUT INSTABILITY ACROSS THE SOUTHERN CWA/CENTRAL IL
INCREASES BY LATE AFTERNOON FOR EXPECTED THUNDERSTORM DEVELOPMENT.
THE SEVERE THREAT WOULD BE PRIMARILY DAMAGING WINDS BUT WITH
DEWPOINTS SURGING BACK INTO THE 70S...HEAVY RAIN WILL BE POSSIBLE
AND WITH TRAINING OF STORMS OVER THE SAME AREAS...SOME POTENTIAL
FOR FLOODING WILL ALSO BE POSSIBLE. BULK OF THIS ACTIVITY APPEARS
TO REMAIN SOUTH OF THE I-80 CORRIDOR WITH THE ACTIVITY MOVING
SOUTHEAST OF THE CWA SATURDAY NIGHT.

HIGH TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON THUNDERSTORMS...
AND HOW SOON THEY FORM AS WELL AS CLOUD COVER. LOW LEVEL THERMAL
PROFILES WOULD SUGGEST UPPER 80S TO AROUND 90 IS DOABLE BUT MADE
NO CHANGES TO CURRENT FORECAST OF MID/UPPER 80S. WITH LITTLE
CHANGE TO AIRMASS SATURDAY NIGHT...AND LIKELY WET GROUND ACROSS
THE SOUTHERN CWA...COMBINED WITH LIGHT WINDS...FOG DEVELOPMENT
SEEMS LIKELY LATE SATURDAY NIGHT INTO SUNDAY MORNING...PRIMARILY
ACROSS THE SOUTHERN CWA.

LOW PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SUNDAY WITH A
TRAILING COLD FRONT MOVING ACROSS THE AREA SUNDAY MORNING. WINDS
WILL SHIFT WEST/NORTHWEST BEHIND THE FRONT AND FORECAST SOUNDINGS
SUGGEST IT WOULD BECOME QUITE BREEZY/WINDY SUNDAY AFTERNOON. ANY
THUNDERSTORM POTENTIAL WOULD LIKELY BE SHORT-LIVED AND ALONG/AHEAD
OF THE FRONT.

A SECOND COLD FRONT/SURGE OF COLDER AIR WILL THEN MOVE SOUTH
ACROSS THE WESTERN LAKES SUNDAY NIGHT. THIS COULD TRIGGER A FEW
SHOWERS OVERNIGHT BUT BULK OF THIS ACTIVITY SHOULD REMAIN
NORTHEAST OF THE CWA. WINDS WILL SHIFT NORTHERLY BEHIND THIS FRONT
WITH HIGHS ON MONDAY ONLY IN THE LOWER/MID 70S. TEMPS MODERATE
BACK INTO THE UPPER 70S/NEAR 80 BY THE MIDDLE OF NEXT WEEK WITH
PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS...MAINLY IN THE
AFTERNOON/EARLY EVENING. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* MVFR CIGS LIKELY TO ARRIVE THIS EVENING
* SMALL THREAT OF SHRA/POSSIBLE TSRA LATE TONIGHT/EARLY SATURDAY
  MORNING

IZZI

//DISCUSSION...UPDATED 00Z...

UPPER LEVEL DISTURBANCE PUSHING SOUTHEAST OF THE REGION SHOULD
ALLOW FOR GENERALLY DRY CONDITIONS THROUGH THE EVENING INTO THE
START OVER THE OVERNIGHT HOURS. INCREASING MOISTURE SURGING INTO
THE REGION LATE TONIGHT INTO EARLY SATURDAY COULD RESULT IN SCTD
SHRA/TSRA DEVELOPING WITH LATEST MODEL GUIDANCE SUGGESTING THE
BEST CHANCES WILL BE SOUTH OF CHICAGO AND ROCKFORD.

WINDS HAVE BEEN BACKING TO THE SOUTH AND EVEN SOUTHEAST OVER NW IL
AND IA AS DEVELOPING WARM FRONT TAKES SHAPE. ANTICIPATE THIS TREND
TO CONTINUE EAST INTO CHGO TERMINALS THIS EVENING WITH WINDS
PROBABLY BECOMING MORE SOUTHERLY AND POSSIBLY EVEN A BIT EAST OF
DUE SOUTH...THOUGH SPEEDS EXPECTED TO BE LIGHT. VERY LOW
CONFIDENCE IN WIND DIRECTION TOMORROW THOUGH SOME SORT OF WESTERLY
COMPONENT SEEMS PROBABLE...HOWEVER AM CONCERNED THAT SPEEDS COULD
BE LIGHT ENOUGH TO ALLOW LAKE BREEZE TO FORM.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM CONFIDENCE IN CIGS FORECAST THROUGH PERIOD
* MEDIUM CONFIDENCE IN TERMINALS REMAINING DRY THROUGH PERIOD
* LOW CONFIDENCE IN WIND DIRECTION SATURDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

IZZI

&&

.MARINE...
205 PM CDT

SOUTHERLY WINDS WILL CONTINUE TO STRENGTHEN OVER THE LAKE THIS
AFTERNOON AND TONIGHT AS HIGH PRESSURE MOVES OFF THE MID ATLANTIC
COAST WHILE LOW PRESSURE MOVES ACROSS THE MIDDLE AND UPPER
MISSISSIPPI VALLEY. THE SURFACE TROUGH LEADING TO THE INCREASE IN
WINDS WILL WEAKEN AND DISSIPATE SATURDAY. LOW PRESSURE DROPPING
OUT OF THE CANADIAN ROCKIES AND TRACKING ACROSS THE SOUTHERN
CANADIAN PRAIRIES WILL BECOME THE MORE DOMINANT FEATURE TO AFFECT
LAKE MICHIGAN AS IT TRACKS ACROSS LAKE SUPERIOR AND LAKE MICHIGAN
SATURDAY NIGHT. WINDS WILL BECOME WEAKER AND MORE VARIABLE WITH THE
LOW WEAKENING AS IT PASSES ACROSS THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT. A SURGE OF MUCH COOLER AIR WITH PUSH SOUTH DOWN
THE LENGTH OF THE LAKE SUNDAY NIGHT AND MONDAY WITH WINDS BECOMING
NORTHERLY AND INCREASING TO ARND 30KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT POSSIBLE. THE MOST LIKELY PERIOD TO SEE THE GALE
FORCE GUSTS SHOULD BE SATURDAY NIGHT INTO SUNDAY MORNING WHEN THE
COLD ADVECTION FOLLOWING THE PASSAGE OF THE LOW AND AN ASSOCIATED
COLD FRONT WILL BE THE STRONGEST. HIGH PRESSURE WILL QUICKLY BUILD
ACROSS THE PLAINS MONDAY AND SPREAD ACROSS THE UPPER MISSISSIPPI
VALLEY AND WESTERN GREAT LAKES MONDAY NIGHT AND THEN SETTLE INTO
THE OHIO VALLEY BY TUESDAY. ANOTHER WEAK LOW TRACKING
SOUTHEASTWARD ACROSS ONTARIO WILL KEEP GENERALLY NORTHWESTERLY TO
WESTERLY WINDS OVER THE LAKE INTO TUESDAY.

WHILE A GALE HEADLINE WILL NOT BE ISSUED WITH THE STRONG NORTH
WINDS SUNDAY NIGHT AND MONDAY...WINDS AND WAVES WILL LIKELY BE
SUFFICIENT TO NECESSITATE A SMALL CRAFT ADVISORY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







000
FXUS63 KLOT 252356
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
656 PM CDT FRI JUL 25 2014

.DISCUSSION...

254 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM CHANCES AND
TIMING THROUGH SUNDAY EVENING...HIGH TEMPS THIS WEEKEND AND THEN
MUCH COOLER TEMPS EARLY NEXT WEEK.

CONFIDENCE REGARDING CONVECTIVE TRENDS OVER THE NEXT 12 TO 18
HOURS IS FAIRLY LOW. A WEAK UPPER WAVE IS MOVING EAST/SOUTHEAST
ACROSS SOUTHERN WISCONSIN WHICH MAY ALLOW ISOLATED ACTIVITY TO
DEVELOP OVER THE NEXT FEW HOURS. ISOLATED ACTIVITY OVER WESTERN IL
APPEARS TO BE ON THE TRAILING EDGE OF THE WAVE PUSHING ACROSS
SOUTHERN IL BUT ALSO ALONG AN INSTABILITY AXIS EXTENDING INTO
EASTERN IA. SHORT TERM/HI RES GUIDANCE SUGGESTS JUST ISOLATED
COVERAGE THROUGH EARLY THIS EVENING THEN DRY THROUGH LATE EVENING
AND POSSIBLY INTO THE OVERNIGHT HOURS.

AS LOW LEVEL MOISTURE RETURNS TONIGHT ANOTHER WAVE CURRENTLY OVER
EASTERN SOUTH DAKOTA MAY AID THUNDERSTORM DEVELOPMENT OVERNIGHT
TOWARD SUNRISE AND PERHAPS OVER THE EASTERN CWA DEPENDING ON
WHEN...AND IF...ANYTHING DOES DEVELOP...THEN EXIT TO THE SOUTHEAST
QUICKLY SATURDAY MORNING. OPTED TO MAINTAIN LIKELY POPS FOR THIS
TIME PERIOD BUT THERE IS LITTLE CONTINUITY IN THE MODELS AND ITS
POSSIBLE MUCH OF THE OVERNIGHT COULD END UP DRY.

TRENDS BECOME A BIT MORE CONFIDENT ON SATURDAY AS THE NORTHERN CWA
REMAINS CAPPED BUT INSTABILITY ACROSS THE SOUTHERN CWA/CENTRAL IL
INCREASES BY LATE AFTERNOON FOR EXPECTED THUNDERSTORM DEVELOPMENT.
THE SEVERE THREAT WOULD BE PRIMARILY DAMAGING WINDS BUT WITH
DEWPOINTS SURGING BACK INTO THE 70S...HEAVY RAIN WILL BE POSSIBLE
AND WITH TRAINING OF STORMS OVER THE SAME AREAS...SOME POTENTIAL
FOR FLOODING WILL ALSO BE POSSIBLE. BULK OF THIS ACTIVITY APPEARS
TO REMAIN SOUTH OF THE I-80 CORRIDOR WITH THE ACTIVITY MOVING
SOUTHEAST OF THE CWA SATURDAY NIGHT.

HIGH TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON THUNDERSTORMS...
AND HOW SOON THEY FORM AS WELL AS CLOUD COVER. LOW LEVEL THERMAL
PROFILES WOULD SUGGEST UPPER 80S TO AROUND 90 IS DOABLE BUT MADE
NO CHANGES TO CURRENT FORECAST OF MID/UPPER 80S. WITH LITTLE
CHANGE TO AIRMASS SATURDAY NIGHT...AND LIKELY WET GROUND ACROSS
THE SOUTHERN CWA...COMBINED WITH LIGHT WINDS...FOG DEVELOPMENT
SEEMS LIKELY LATE SATURDAY NIGHT INTO SUNDAY MORNING...PRIMARILY
ACROSS THE SOUTHERN CWA.

LOW PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SUNDAY WITH A
TRAILING COLD FRONT MOVING ACROSS THE AREA SUNDAY MORNING. WINDS
WILL SHIFT WEST/NORTHWEST BEHIND THE FRONT AND FORECAST SOUNDINGS
SUGGEST IT WOULD BECOME QUITE BREEZY/WINDY SUNDAY AFTERNOON. ANY
THUNDERSTORM POTENTIAL WOULD LIKELY BE SHORT-LIVED AND ALONG/AHEAD
OF THE FRONT.

A SECOND COLD FRONT/SURGE OF COLDER AIR WILL THEN MOVE SOUTH
ACROSS THE WESTERN LAKES SUNDAY NIGHT. THIS COULD TRIGGER A FEW
SHOWERS OVERNIGHT BUT BULK OF THIS ACTIVITY SHOULD REMAIN
NORTHEAST OF THE CWA. WINDS WILL SHIFT NORTHERLY BEHIND THIS FRONT
WITH HIGHS ON MONDAY ONLY IN THE LOWER/MID 70S. TEMPS MODERATE
BACK INTO THE UPPER 70S/NEAR 80 BY THE MIDDLE OF NEXT WEEK WITH
PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS...MAINLY IN THE
AFTERNOON/EARLY EVENING. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* MVFR CIGS LIKELY TO ARRIVE THIS EVENING
* SMALL THREAT OF SHRA/POSSIBLE TSRA LATE TONIGHT/EARLY SATURDAY
  MORNING

IZZI

//DISCUSSION...UPDATED 00Z...

UPPER LEVEL DISTURBANCE PUSHING SOUTHEAST OF THE REGION SHOULD
ALLOW FOR GENERALLY DRY CONDITIONS THROUGH THE EVENING INTO THE
START OVER THE OVERNIGHT HOURS. INCREASING MOISTURE SURGING INTO
THE REGION LATE TONIGHT INTO EARLY SATURDAY COULD RESULT IN SCTD
SHRA/TSRA DEVELOPING WITH LATEST MODEL GUIDANCE SUGGESTING THE
BEST CHANCES WILL BE SOUTH OF CHICAGO AND ROCKFORD.

WINDS HAVE BEEN BACKING TO THE SOUTH AND EVEN SOUTHEAST OVER NW IL
AND IA AS DEVELOPING WARM FRONT TAKES SHAPE. ANTICIPATE THIS TREND
TO CONTINUE EAST INTO CHGO TERMINALS THIS EVENING WITH WINDS
PROBABLY BECOMING MORE SOUTHERLY AND POSSIBLY EVEN A BIT EAST OF
DUE SOUTH...THOUGH SPEEDS EXPECTED TO BE LIGHT. VERY LOW
CONFIDENCE IN WIND DIRECTION TOMORROW THOUGH SOME SORT OF WESTERLY
COMPONENT SEEMS PROBABLE...HOWEVER AM CONCERNED THAT SPEEDS COULD
BE LIGHT ENOUGH TO ALLOW LAKE BREEZE TO FORM.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM CONFIDENCE IN CIGS FORECAST THROUGH PERIOD
* MEDIUM CONFIDENCE IN TERMINALS REMAINING DRY THROUGH PERIOD
* LOW CONFIDENCE IN WIND DIRECTION SATURDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

IZZI

&&

.MARINE...
205 PM CDT

SOUTHERLY WINDS WILL CONTINUE TO STRENGTHEN OVER THE LAKE THIS
AFTERNOON AND TONIGHT AS HIGH PRESSURE MOVES OFF THE MID ATLANTIC
COAST WHILE LOW PRESSURE MOVES ACROSS THE MIDDLE AND UPPER
MISSISSIPPI VALLEY. THE SURFACE TROUGH LEADING TO THE INCREASE IN
WINDS WILL WEAKEN AND DISSIPATE SATURDAY. LOW PRESSURE DROPPING
OUT OF THE CANADIAN ROCKIES AND TRACKING ACROSS THE SOUTHERN
CANADIAN PRAIRIES WILL BECOME THE MORE DOMINANT FEATURE TO AFFECT
LAKE MICHIGAN AS IT TRACKS ACROSS LAKE SUPERIOR AND LAKE MICHIGAN
SATURDAY NIGHT. WINDS WILL BECOME WEAKER AND MORE VARIABLE WITH THE
LOW WEAKENING AS IT PASSES ACROSS THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT. A SURGE OF MUCH COOLER AIR WITH PUSH SOUTH DOWN
THE LENGTH OF THE LAKE SUNDAY NIGHT AND MONDAY WITH WINDS BECOMING
NORTHERLY AND INCREASING TO ARND 30KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT POSSIBLE. THE MOST LIKELY PERIOD TO SEE THE GALE
FORCE GUSTS SHOULD BE SATURDAY NIGHT INTO SUNDAY MORNING WHEN THE
COLD ADVECTION FOLLOWING THE PASSAGE OF THE LOW AND AN ASSOCIATED
COLD FRONT WILL BE THE STRONGEST. HIGH PRESSURE WILL QUICKLY BUILD
ACROSS THE PLAINS MONDAY AND SPREAD ACROSS THE UPPER MISSISSIPPI
VALLEY AND WESTERN GREAT LAKES MONDAY NIGHT AND THEN SETTLE INTO
THE OHIO VALLEY BY TUESDAY. ANOTHER WEAK LOW TRACKING
SOUTHEASTWARD ACROSS ONTARIO WILL KEEP GENERALLY NORTHWESTERLY TO
WESTERLY WINDS OVER THE LAKE INTO TUESDAY.

WHILE A GALE HEADLINE WILL NOT BE ISSUED WITH THE STRONG NORTH
WINDS SUNDAY NIGHT AND MONDAY...WINDS AND WAVES WILL LIKELY BE
SUFFICIENT TO NECESSITATE A SMALL CRAFT ADVISORY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO






000
FXUS63 KLOT 252356
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
656 PM CDT FRI JUL 25 2014

.DISCUSSION...

254 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM CHANCES AND
TIMING THROUGH SUNDAY EVENING...HIGH TEMPS THIS WEEKEND AND THEN
MUCH COOLER TEMPS EARLY NEXT WEEK.

CONFIDENCE REGARDING CONVECTIVE TRENDS OVER THE NEXT 12 TO 18
HOURS IS FAIRLY LOW. A WEAK UPPER WAVE IS MOVING EAST/SOUTHEAST
ACROSS SOUTHERN WISCONSIN WHICH MAY ALLOW ISOLATED ACTIVITY TO
DEVELOP OVER THE NEXT FEW HOURS. ISOLATED ACTIVITY OVER WESTERN IL
APPEARS TO BE ON THE TRAILING EDGE OF THE WAVE PUSHING ACROSS
SOUTHERN IL BUT ALSO ALONG AN INSTABILITY AXIS EXTENDING INTO
EASTERN IA. SHORT TERM/HI RES GUIDANCE SUGGESTS JUST ISOLATED
COVERAGE THROUGH EARLY THIS EVENING THEN DRY THROUGH LATE EVENING
AND POSSIBLY INTO THE OVERNIGHT HOURS.

AS LOW LEVEL MOISTURE RETURNS TONIGHT ANOTHER WAVE CURRENTLY OVER
EASTERN SOUTH DAKOTA MAY AID THUNDERSTORM DEVELOPMENT OVERNIGHT
TOWARD SUNRISE AND PERHAPS OVER THE EASTERN CWA DEPENDING ON
WHEN...AND IF...ANYTHING DOES DEVELOP...THEN EXIT TO THE SOUTHEAST
QUICKLY SATURDAY MORNING. OPTED TO MAINTAIN LIKELY POPS FOR THIS
TIME PERIOD BUT THERE IS LITTLE CONTINUITY IN THE MODELS AND ITS
POSSIBLE MUCH OF THE OVERNIGHT COULD END UP DRY.

TRENDS BECOME A BIT MORE CONFIDENT ON SATURDAY AS THE NORTHERN CWA
REMAINS CAPPED BUT INSTABILITY ACROSS THE SOUTHERN CWA/CENTRAL IL
INCREASES BY LATE AFTERNOON FOR EXPECTED THUNDERSTORM DEVELOPMENT.
THE SEVERE THREAT WOULD BE PRIMARILY DAMAGING WINDS BUT WITH
DEWPOINTS SURGING BACK INTO THE 70S...HEAVY RAIN WILL BE POSSIBLE
AND WITH TRAINING OF STORMS OVER THE SAME AREAS...SOME POTENTIAL
FOR FLOODING WILL ALSO BE POSSIBLE. BULK OF THIS ACTIVITY APPEARS
TO REMAIN SOUTH OF THE I-80 CORRIDOR WITH THE ACTIVITY MOVING
SOUTHEAST OF THE CWA SATURDAY NIGHT.

HIGH TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON THUNDERSTORMS...
AND HOW SOON THEY FORM AS WELL AS CLOUD COVER. LOW LEVEL THERMAL
PROFILES WOULD SUGGEST UPPER 80S TO AROUND 90 IS DOABLE BUT MADE
NO CHANGES TO CURRENT FORECAST OF MID/UPPER 80S. WITH LITTLE
CHANGE TO AIRMASS SATURDAY NIGHT...AND LIKELY WET GROUND ACROSS
THE SOUTHERN CWA...COMBINED WITH LIGHT WINDS...FOG DEVELOPMENT
SEEMS LIKELY LATE SATURDAY NIGHT INTO SUNDAY MORNING...PRIMARILY
ACROSS THE SOUTHERN CWA.

LOW PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SUNDAY WITH A
TRAILING COLD FRONT MOVING ACROSS THE AREA SUNDAY MORNING. WINDS
WILL SHIFT WEST/NORTHWEST BEHIND THE FRONT AND FORECAST SOUNDINGS
SUGGEST IT WOULD BECOME QUITE BREEZY/WINDY SUNDAY AFTERNOON. ANY
THUNDERSTORM POTENTIAL WOULD LIKELY BE SHORT-LIVED AND ALONG/AHEAD
OF THE FRONT.

A SECOND COLD FRONT/SURGE OF COLDER AIR WILL THEN MOVE SOUTH
ACROSS THE WESTERN LAKES SUNDAY NIGHT. THIS COULD TRIGGER A FEW
SHOWERS OVERNIGHT BUT BULK OF THIS ACTIVITY SHOULD REMAIN
NORTHEAST OF THE CWA. WINDS WILL SHIFT NORTHERLY BEHIND THIS FRONT
WITH HIGHS ON MONDAY ONLY IN THE LOWER/MID 70S. TEMPS MODERATE
BACK INTO THE UPPER 70S/NEAR 80 BY THE MIDDLE OF NEXT WEEK WITH
PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS...MAINLY IN THE
AFTERNOON/EARLY EVENING. CMS

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* MVFR CIGS LIKELY TO ARRIVE THIS EVENING
* SMALL THREAT OF SHRA/POSSIBLE TSRA LATE TONIGHT/EARLY SATURDAY
  MORNING

IZZI

//DISCUSSION...UPDATED 00Z...

UPPER LEVEL DISTURBANCE PUSHING SOUTHEAST OF THE REGION SHOULD
ALLOW FOR GENERALLY DRY CONDITIONS THROUGH THE EVENING INTO THE
START OVER THE OVERNIGHT HOURS. INCREASING MOISTURE SURGING INTO
THE REGION LATE TONIGHT INTO EARLY SATURDAY COULD RESULT IN SCTD
SHRA/TSRA DEVELOPING WITH LATEST MODEL GUIDANCE SUGGESTING THE
BEST CHANCES WILL BE SOUTH OF CHICAGO AND ROCKFORD.

WINDS HAVE BEEN BACKING TO THE SOUTH AND EVEN SOUTHEAST OVER NW IL
AND IA AS DEVELOPING WARM FRONT TAKES SHAPE. ANTICIPATE THIS TREND
TO CONTINUE EAST INTO CHGO TERMINALS THIS EVENING WITH WINDS
PROBABLY BECOMING MORE SOUTHERLY AND POSSIBLY EVEN A BIT EAST OF
DUE SOUTH...THOUGH SPEEDS EXPECTED TO BE LIGHT. VERY LOW
CONFIDENCE IN WIND DIRECTION TOMORROW THOUGH SOME SORT OF WESTERLY
COMPONENT SEEMS PROBABLE...HOWEVER AM CONCERNED THAT SPEEDS COULD
BE LIGHT ENOUGH TO ALLOW LAKE BREEZE TO FORM.

IZZI

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM CONFIDENCE IN CIGS FORECAST THROUGH PERIOD
* MEDIUM CONFIDENCE IN TERMINALS REMAINING DRY THROUGH PERIOD
* LOW CONFIDENCE IN WIND DIRECTION SATURDAY

IZZI

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE OF TSRA.

MONDAY...VFR. GUSTY NNE WINDS.

TUESDAY THROUGH THURSDAY...GENERALLY VFR.

IZZI

&&

.MARINE...
205 PM CDT

SOUTHERLY WINDS WILL CONTINUE TO STRENGTHEN OVER THE LAKE THIS
AFTERNOON AND TONIGHT AS HIGH PRESSURE MOVES OFF THE MID ATLANTIC
COAST WHILE LOW PRESSURE MOVES ACROSS THE MIDDLE AND UPPER
MISSISSIPPI VALLEY. THE SURFACE TROUGH LEADING TO THE INCREASE IN
WINDS WILL WEAKEN AND DISSIPATE SATURDAY. LOW PRESSURE DROPPING
OUT OF THE CANADIAN ROCKIES AND TRACKING ACROSS THE SOUTHERN
CANADIAN PRAIRIES WILL BECOME THE MORE DOMINANT FEATURE TO AFFECT
LAKE MICHIGAN AS IT TRACKS ACROSS LAKE SUPERIOR AND LAKE MICHIGAN
SATURDAY NIGHT. WINDS WILL BECOME WEAKER AND MORE VARIABLE WITH THE
LOW WEAKENING AS IT PASSES ACROSS THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT. A SURGE OF MUCH COOLER AIR WITH PUSH SOUTH DOWN
THE LENGTH OF THE LAKE SUNDAY NIGHT AND MONDAY WITH WINDS BECOMING
NORTHERLY AND INCREASING TO ARND 30KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT POSSIBLE. THE MOST LIKELY PERIOD TO SEE THE GALE
FORCE GUSTS SHOULD BE SATURDAY NIGHT INTO SUNDAY MORNING WHEN THE
COLD ADVECTION FOLLOWING THE PASSAGE OF THE LOW AND AN ASSOCIATED
COLD FRONT WILL BE THE STRONGEST. HIGH PRESSURE WILL QUICKLY BUILD
ACROSS THE PLAINS MONDAY AND SPREAD ACROSS THE UPPER MISSISSIPPI
VALLEY AND WESTERN GREAT LAKES MONDAY NIGHT AND THEN SETTLE INTO
THE OHIO VALLEY BY TUESDAY. ANOTHER WEAK LOW TRACKING
SOUTHEASTWARD ACROSS ONTARIO WILL KEEP GENERALLY NORTHWESTERLY TO
WESTERLY WINDS OVER THE LAKE INTO TUESDAY.

WHILE A GALE HEADLINE WILL NOT BE ISSUED WITH THE STRONG NORTH
WINDS SUNDAY NIGHT AND MONDAY...WINDS AND WAVES WILL LIKELY BE
SUFFICIENT TO NECESSITATE A SMALL CRAFT ADVISORY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO







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