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000
FXUS63 KIWX 211010
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
610 AM EDT SUN SEP 21 2014

.SYNOPSIS...
ISSUED AT 327 AM EDT SUN SEP 21 2014

A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE AREA EARLY THIS
MORNING...USHERING IN MUCH COOLER AIR ALONG WITH GUSTY NORTHWEST
BREEZES. A DISTURBANCE ALOFT WILL CROSS THE AREA THIS AFTERNOON
AND MAY GIVE RISE TO A FEW LIGHT SHOWERS. HIGH TEMPERATURES WILL BE
IN THE LOW TO MID 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EDT SUN SEP 21 2014

PV ANOMALY ASSOCD/W INTENSE SW OVR NRN WI WILL DIVE RAPIDLY SEWD
INTO NRN IN BY MIDDAY AS LG SCALE MID LVL TROUGH AMPLIFIES SHARPLY
SEWD. SFC CDFNT IN ASSOCN/W THIS SYS EXTENDS FM WRN LK MI SWWD INTO
CNTRL IN AND WILL CLEAR ERN CWA BY DAYBREAK. SRN FLANK OF CONVN
ALG THIS FTR WILL CARRY EWD THROUGH SRN MI OTRWS SCT SHRA/TSRA
CONT TO FESTER WITHIN DOWNSTREAM WAA OVERTOP LEFT OVER OUTFLW
BUBBLE FM CONVN LAST EVENING YET ON THE WAY OUT OVR FAR SERN ZONES.
AGAIN THOUGH XPC ALL OF THIS WILL BE EAST OF CWA BY SUNRISE AND
WILL THEN AWAIT ARRIVAL OF MID LVL TROUGH ACRS THE NW CWA TWD THE
NOON HOUR FOLLOWED BY RAPID SEWD PIVOT THROUGH MID AFTN.

POST FNTL AIRMASS GETS GUTTED AS STG CAA WING DRIVES SEWD THROUGH
THIS MORNING. PALTRY LEFT OVR RESIDUAL LL THETA-E IN COMBINATION
W/INNOCUOUS VERTICAL ASCENT WARRANT TEMPERING POPS AS REFLECTED
BOTH IN MOS TRENDS AND SEEN IN NEARLY ALL HIGHRES SOLUTIONS.

TEMPS WILL BE SHARPLY COLDER VS YDA/S UNSEASONABLY WARM READINGS
W/HIGHS IN THE LOW TO MID 60S. SFC RIDGE BLDS EAST OVERNIGHT W/CLRG
AND WILL FOLLOW COLDER SIDE OF MOS GUIDANCE.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 327 AM EDT SUN SEP 21 2014

LITTLE TO TALK ABOUT FOR THE LONG TERM AS HIGH PRESSURE WILL DRIFT
ACROSS THE REGION THROUGH TUESDAY BEFORE PARKING TO THE EAST FOR THE
REMAINDER OF THE WEEK INTO THE WEEKEND. COOLEST TEMPS WILL BE SEEN
MONDAY INTO MONDAY NIGHT GIVEN PROXIMITY OF RIDGE AXIS. MORNING LOWS
MONDAY WILL BE IN THE LOWER 40S WITH TEMPERATURES REBOUNDING ONLY
INTO THE 60S AND THEN BACK DOWN INTO THE MID 40S MONDAY NIGHT.

FROM TUESDAY ON...SLOW MODERATION WILL TAKE PLACE WITH HIGHS
REACHING INTO THE LOWER TO MIDDLE 70S AND NO SIGNS OF RAIN.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 609 AM EDT SUN SEP 21 2014

LEADING EDGE OF VIGOROUS LL CAA WING NOW OVERSPREADING NW CWA AND
WILL RAPIDLY SWEEP SEWD THROUGH CWA BY MID MORNING. ROBUST RISE/FALL
COUPLET YIELDING FAIRLY GUSTY POST FNTL NWRLY WINDS W/GUSTS UP TO
30KTS NOTED IN 10Z OBS.

UPSTREAM SHRA IN ASSOCN/W SW WRAPPING UP ACRS ERN WI AND UNDERNEATH
MID LVL COLD POCKET WILL GENERALLY CLIP FAR NE PORTION OF CWA TWD
LT MORNING. TRAILING VORT LOBE AND WK LL FORCED ASCENT MAY YIELD A
SPRINKLE/LIGHT SHRA AT THE TERMINALS EARLY THIS AFTN BUT WILL AGAIN
DEFER ANY MENTION AS LTL IF ANY SENSIBLE IMPACT XPCD. PRIMARY
AVIATION HAZARD GOING FWD WILL BE ESCALATION OF SFC GRADIENT ESP AFT
SUNRISE UNDERNEATH MID LVL DRYSLOT. LAMP GUIDANCE CONTS TO UPTICK
SLIGHTLY HIGHER W/NWRLY SFC GUSTS ABV 25KTS FOR A TIME LIKELY FM MID
MORNING THROUGH MID AFTN.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 PM EDT MONDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...T
SHORT TERM...T
LONG TERM...FISHER
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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000
FXUS63 KIWX 211010
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
610 AM EDT SUN SEP 21 2014

.SYNOPSIS...
ISSUED AT 327 AM EDT SUN SEP 21 2014

A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE AREA EARLY THIS
MORNING...USHERING IN MUCH COOLER AIR ALONG WITH GUSTY NORTHWEST
BREEZES. A DISTURBANCE ALOFT WILL CROSS THE AREA THIS AFTERNOON
AND MAY GIVE RISE TO A FEW LIGHT SHOWERS. HIGH TEMPERATURES WILL BE
IN THE LOW TO MID 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EDT SUN SEP 21 2014

PV ANOMALY ASSOCD/W INTENSE SW OVR NRN WI WILL DIVE RAPIDLY SEWD
INTO NRN IN BY MIDDAY AS LG SCALE MID LVL TROUGH AMPLIFIES SHARPLY
SEWD. SFC CDFNT IN ASSOCN/W THIS SYS EXTENDS FM WRN LK MI SWWD INTO
CNTRL IN AND WILL CLEAR ERN CWA BY DAYBREAK. SRN FLANK OF CONVN
ALG THIS FTR WILL CARRY EWD THROUGH SRN MI OTRWS SCT SHRA/TSRA
CONT TO FESTER WITHIN DOWNSTREAM WAA OVERTOP LEFT OVER OUTFLW
BUBBLE FM CONVN LAST EVENING YET ON THE WAY OUT OVR FAR SERN ZONES.
AGAIN THOUGH XPC ALL OF THIS WILL BE EAST OF CWA BY SUNRISE AND
WILL THEN AWAIT ARRIVAL OF MID LVL TROUGH ACRS THE NW CWA TWD THE
NOON HOUR FOLLOWED BY RAPID SEWD PIVOT THROUGH MID AFTN.

POST FNTL AIRMASS GETS GUTTED AS STG CAA WING DRIVES SEWD THROUGH
THIS MORNING. PALTRY LEFT OVR RESIDUAL LL THETA-E IN COMBINATION
W/INNOCUOUS VERTICAL ASCENT WARRANT TEMPERING POPS AS REFLECTED
BOTH IN MOS TRENDS AND SEEN IN NEARLY ALL HIGHRES SOLUTIONS.

TEMPS WILL BE SHARPLY COLDER VS YDA/S UNSEASONABLY WARM READINGS
W/HIGHS IN THE LOW TO MID 60S. SFC RIDGE BLDS EAST OVERNIGHT W/CLRG
AND WILL FOLLOW COLDER SIDE OF MOS GUIDANCE.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 327 AM EDT SUN SEP 21 2014

LITTLE TO TALK ABOUT FOR THE LONG TERM AS HIGH PRESSURE WILL DRIFT
ACROSS THE REGION THROUGH TUESDAY BEFORE PARKING TO THE EAST FOR THE
REMAINDER OF THE WEEK INTO THE WEEKEND. COOLEST TEMPS WILL BE SEEN
MONDAY INTO MONDAY NIGHT GIVEN PROXIMITY OF RIDGE AXIS. MORNING LOWS
MONDAY WILL BE IN THE LOWER 40S WITH TEMPERATURES REBOUNDING ONLY
INTO THE 60S AND THEN BACK DOWN INTO THE MID 40S MONDAY NIGHT.

FROM TUESDAY ON...SLOW MODERATION WILL TAKE PLACE WITH HIGHS
REACHING INTO THE LOWER TO MIDDLE 70S AND NO SIGNS OF RAIN.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 609 AM EDT SUN SEP 21 2014

LEADING EDGE OF VIGOROUS LL CAA WING NOW OVERSPREADING NW CWA AND
WILL RAPIDLY SWEEP SEWD THROUGH CWA BY MID MORNING. ROBUST RISE/FALL
COUPLET YIELDING FAIRLY GUSTY POST FNTL NWRLY WINDS W/GUSTS UP TO
30KTS NOTED IN 10Z OBS.

UPSTREAM SHRA IN ASSOCN/W SW WRAPPING UP ACRS ERN WI AND UNDERNEATH
MID LVL COLD POCKET WILL GENERALLY CLIP FAR NE PORTION OF CWA TWD
LT MORNING. TRAILING VORT LOBE AND WK LL FORCED ASCENT MAY YIELD A
SPRINKLE/LIGHT SHRA AT THE TERMINALS EARLY THIS AFTN BUT WILL AGAIN
DEFER ANY MENTION AS LTL IF ANY SENSIBLE IMPACT XPCD. PRIMARY
AVIATION HAZARD GOING FWD WILL BE ESCALATION OF SFC GRADIENT ESP AFT
SUNRISE UNDERNEATH MID LVL DRYSLOT. LAMP GUIDANCE CONTS TO UPTICK
SLIGHTLY HIGHER W/NWRLY SFC GUSTS ABV 25KTS FOR A TIME LIKELY FM MID
MORNING THROUGH MID AFTN.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 PM EDT MONDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...T
SHORT TERM...T
LONG TERM...FISHER
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 210730
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
330 AM EDT SUN SEP 21 2014

.SYNOPSIS...
ISSUED AT 327 AM EDT SUN SEP 21 2014

A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE AREA EARLY THIS
MORNING...USHERING IN MUCH COOLER AIR ALONG WITH GUSTY NORTHWEST
BREEZES. A DISTURBANCE ALOFT WILL CROSS THE AREA THIS AFTERNOON
AND MAY GIVE RISE TO A FEW LIGHT SHOWERS. HIGH TEMPERATURES WILL BE
IN THE LOW TO MID 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EDT SUN SEP 21 2014

PV ANOMALY ASSOCD/W INTENSE SW OVR NRN WI WILL DIVE RAPIDLY SEWD
INTO NRN IN BY MIDDAY AS LG SCALE MID LVL TROUGH AMPLIFIES SHARPLY
SEWD. SFC CDFNT IN ASSOCN/W THIS SYS EXTENDS FM WRN LK MI SWWD INTO
CNTRL IN AND WILL CLEAR ERN CWA BY DAYBREAK. SRN FLANK OF CONVN
ALG THIS FTR WILL CARRY EWD THROUGH SRN MI OTRWS SCT SHRA/TSRA
CONT TO FESTER WITHIN DOWNSTREAM WAA OVERTOP LEFT OVER OUTFLW
BUBBLE FM CONVN LAST EVENING YET ON THE WAY OUT OVR FAR SERN ZONES.
AGAIN THOUGH XPC ALL OF THIS WILL BE EAST OF CWA BY SUNRISE AND
WILL THEN AWAIT ARRIVAL OF MID LVL TROUGH ACRS THE NW CWA TWD THE
NOON HOUR FOLLOWED BY RAPID SEWD PIVOT THROUGH MID AFTN.

POST FNTL AIRMASS GETS GUTTED AS STG CAA WING DRIVES SEWD THROUGH
THIS MORNING. PALTRY LEFT OVR RESIDUAL LL THETA-E IN COMBINATION
W/INNOCUOUS VERTICAL ASCENT WARRANT TEMPERING POPS AS REFLECTED
BOTH IN MOS TRENDS AND SEEN IN NEARLY ALL HIGHRES SOLUTIONS.

TEMPS WILL BE SHARPLY COLDER VS YDA/S UNSEASONABLY WARM READINGS
W/HIGHS IN THE LOW TO MID 60S. SFC RIDGE BLDS EAST OVERNIGHT W/CLRG
AND WILL FOLLOW COLDER SIDE OF MOS GUIDANCE.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 327 AM EDT SUN SEP 21 2014

LITTLE TO TALK ABOUT FOR THE LONG TERM AS HIGH PRESSURE WILL DRIFT
ACROSS THE REGION THROUGH TUESDAY BEFORE PARKING TO THE EAST FOR THE
REMAINDER OF THE WEEK INTO THE WEEKEND. COOLEST TEMPS WILL BE SEEN
MONDAY INTO MONDAY NIGHT GIVEN PROXIMITY OF RIDGE AXIS. MORNING LOWS
MONDAY WILL BE IN THE LOWER 40S WITH TEMPERATURES REBOUNDING ONLY
INTO THE 60S AND THEN BACK DOWN INTO THE MID 40S MONDAY NIGHT.

FROM TUESDAY ON...SLOW MODERATION WILL TAKE PLACE WITH HIGHS
REACHING INTO THE LOWER TO MIDDLE 70S AND NO SIGNS OF RAIN.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 154 AM EDT SUN SEP 21 2014

THORNY NR TERM W/CURRENT VARIABLE CIGS IN PLACE AND TAIL END OF
NEARING LINE OF STG STORMS ALG SHARP SFC CDFNT OVR CHICAGO.
WANING WAA WING AHD OF THIS FTR STILL FESTERING OVR ERN AREAS BUT
MOST SIG IMMEDIATE SHRA THREAT LOOKS TO PASS NR OR JUST SOUTH OF
KFWA. OTRWS GIVEN PROXIMITY OF UPSTREAM CONV LINE TO KSBN AND
RAPID SEWD MOVEMENT WILL ROLL W/A BRIEF TEMPO MENTION TO ELUCIDATE
WIND GUST POTENTIAL. THIS MAY SURVIVE EVEN TO KFWA BUT OPTED TO
LEAVE MENTION OUT AND AMEND AS NECESSARY GIVEN WANING ELEVATED
INSTABILITY POOL.

OTRWS STG UPSTREAM CAA WING WILL RAPIDLY DRIVE SEWD THROUGH DAYBREAK
W/STG MIXING DVLPG BY MID MORNING AND CONTG THROUGH AFTN. NWRLY SFC
GUSTS AOA 25KTS XPCD AT BOTH TERMINALS.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...T
SHORT TERM...T
LONG TERM...FISHER
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIWX 210730
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
330 AM EDT SUN SEP 21 2014

.SYNOPSIS...
ISSUED AT 327 AM EDT SUN SEP 21 2014

A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE AREA EARLY THIS
MORNING...USHERING IN MUCH COOLER AIR ALONG WITH GUSTY NORTHWEST
BREEZES. A DISTURBANCE ALOFT WILL CROSS THE AREA THIS AFTERNOON
AND MAY GIVE RISE TO A FEW LIGHT SHOWERS. HIGH TEMPERATURES WILL BE
IN THE LOW TO MID 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EDT SUN SEP 21 2014

PV ANOMALY ASSOCD/W INTENSE SW OVR NRN WI WILL DIVE RAPIDLY SEWD
INTO NRN IN BY MIDDAY AS LG SCALE MID LVL TROUGH AMPLIFIES SHARPLY
SEWD. SFC CDFNT IN ASSOCN/W THIS SYS EXTENDS FM WRN LK MI SWWD INTO
CNTRL IN AND WILL CLEAR ERN CWA BY DAYBREAK. SRN FLANK OF CONVN
ALG THIS FTR WILL CARRY EWD THROUGH SRN MI OTRWS SCT SHRA/TSRA
CONT TO FESTER WITHIN DOWNSTREAM WAA OVERTOP LEFT OVER OUTFLW
BUBBLE FM CONVN LAST EVENING YET ON THE WAY OUT OVR FAR SERN ZONES.
AGAIN THOUGH XPC ALL OF THIS WILL BE EAST OF CWA BY SUNRISE AND
WILL THEN AWAIT ARRIVAL OF MID LVL TROUGH ACRS THE NW CWA TWD THE
NOON HOUR FOLLOWED BY RAPID SEWD PIVOT THROUGH MID AFTN.

POST FNTL AIRMASS GETS GUTTED AS STG CAA WING DRIVES SEWD THROUGH
THIS MORNING. PALTRY LEFT OVR RESIDUAL LL THETA-E IN COMBINATION
W/INNOCUOUS VERTICAL ASCENT WARRANT TEMPERING POPS AS REFLECTED
BOTH IN MOS TRENDS AND SEEN IN NEARLY ALL HIGHRES SOLUTIONS.

TEMPS WILL BE SHARPLY COLDER VS YDA/S UNSEASONABLY WARM READINGS
W/HIGHS IN THE LOW TO MID 60S. SFC RIDGE BLDS EAST OVERNIGHT W/CLRG
AND WILL FOLLOW COLDER SIDE OF MOS GUIDANCE.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 327 AM EDT SUN SEP 21 2014

LITTLE TO TALK ABOUT FOR THE LONG TERM AS HIGH PRESSURE WILL DRIFT
ACROSS THE REGION THROUGH TUESDAY BEFORE PARKING TO THE EAST FOR THE
REMAINDER OF THE WEEK INTO THE WEEKEND. COOLEST TEMPS WILL BE SEEN
MONDAY INTO MONDAY NIGHT GIVEN PROXIMITY OF RIDGE AXIS. MORNING LOWS
MONDAY WILL BE IN THE LOWER 40S WITH TEMPERATURES REBOUNDING ONLY
INTO THE 60S AND THEN BACK DOWN INTO THE MID 40S MONDAY NIGHT.

FROM TUESDAY ON...SLOW MODERATION WILL TAKE PLACE WITH HIGHS
REACHING INTO THE LOWER TO MIDDLE 70S AND NO SIGNS OF RAIN.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 154 AM EDT SUN SEP 21 2014

THORNY NR TERM W/CURRENT VARIABLE CIGS IN PLACE AND TAIL END OF
NEARING LINE OF STG STORMS ALG SHARP SFC CDFNT OVR CHICAGO.
WANING WAA WING AHD OF THIS FTR STILL FESTERING OVR ERN AREAS BUT
MOST SIG IMMEDIATE SHRA THREAT LOOKS TO PASS NR OR JUST SOUTH OF
KFWA. OTRWS GIVEN PROXIMITY OF UPSTREAM CONV LINE TO KSBN AND
RAPID SEWD MOVEMENT WILL ROLL W/A BRIEF TEMPO MENTION TO ELUCIDATE
WIND GUST POTENTIAL. THIS MAY SURVIVE EVEN TO KFWA BUT OPTED TO
LEAVE MENTION OUT AND AMEND AS NECESSARY GIVEN WANING ELEVATED
INSTABILITY POOL.

OTRWS STG UPSTREAM CAA WING WILL RAPIDLY DRIVE SEWD THROUGH DAYBREAK
W/STG MIXING DVLPG BY MID MORNING AND CONTG THROUGH AFTN. NWRLY SFC
GUSTS AOA 25KTS XPCD AT BOTH TERMINALS.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...T
SHORT TERM...T
LONG TERM...FISHER
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 210555
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
155 AM EDT SUN SEP 21 2014

.SYNOPSIS...
ISSUED AT 745 PM EDT SAT SEP 20 2014

AN UPPER LEVEL DISTURBANCE AND COLD FRONTAL BOUNDARY PRODUCED
SHOWERS AND THUNDERSTORMS SATURDAY EVENING. THE COVERAGE AND
INTENSITY WILL DIMINISH OVERNIGHT. ANOTHER UPPER LEVEL DISTURBANCE
WILL BRING ANOTHER CHANCE OF SHOWERS ON SUNDAY...WITH EVEN AN
ISOLATED THUNDERSTORM NEAR THE MICHIGAN...OHIO AND INDIANA BORDER
REGION. THEN CONDITIONS WILL DRY OUT SUNDAY NIGHT AS A RIDGE OF
HIGH PRESSURE BUILDS INTO THE AREA THROUGH THE EARLY PARTS OF NEXT
WEEK. LOW TONIGHT WILL DROP INTO THE LOWER 60S AND HIGHS ON SUNDAY
WILL BE COOLER...IN THE MID 60S TO LOWER 70S.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014

MAIN FORECAST CONCERN WILL BE SEVERE WEATHER POTENTIAL THIS
EVENING.

A STRONG UPPER VORT MAX TRACKING ACROSS NORTHWEST ILLINOIS AT
THIS TIME WILL BE THE PRIMARY SYNOPTIC FEATURE OF INTEREST THIS
EVENING. THIS SHORT WAVE HAS AN IMPRESSIVE WATER VAPOR
PRESENTATION...WITH A VERY SHARP UPPER LEVEL MOISTURE
DISCONTINUITY. MOST VIGOROUS CONVECTION AT THE PRESENT TIME HAS
DEVELOPED ACROSS NORTHEAST ILLINOIS AND ABOUT TO ENTER FAR WEST
CENTRAL PORTIONS OF IWX FORECAST AREA. DEEP LAYER SHEAR WILL
CONTINUE TO STRENGTHEN THROUGH THE REMAINDER OF THE
AFTERNOON/EARLY EVENING...WITH 0-3KM SHEAR VALUES ALSO INCREASING
INTO THE 35 TO 40 KNOT RANGE. THIS SHOULD HELP TO SUSTAIN WIND
THREAT INTO WESTERN PORTIONS OF THE AREA AND BALANCE COLD POOL
STRENGTH. STORMS SHOULD EVENTUALLY BEGIN TO OUTRUN MOST
PRONOUNCED INSTABILITY AXIS ACROSS NORTHEAST ILLINOIS/NORTHWEST
INDIANA WHERE 100 HPA MLCAPES ON THE ORDER OF 750-1500 J/KG ARE
EXPECTED. THIS MAY TEND TO DIMINISH STORM INTENSITY ACROSS
EASTERN HALF OR EASTERN THIRD OF THE AREA LATER THIS EVENING.
WHILE DAMAGING WIND IS THE MAIN THREAT...A FEW INSTANCES OF LARGE
HAIL WILL BE POSSIBLE WITH THE STRONGER CORES.

WHILE STRONGEST STORMS MAY TEND TO DIMINISH ACROSS EASTERN
PORTIONS OF THE AREA LATER THIS EVENING...PASSAGE OF PRIMARY
UPPER VORT MAX ACROSS NORTHWEST ILLINOIS LATER TONIGHT WILL BE
ACCOMPANIED BY SECONDARY LOW LEVEL MOISTURE POOLING AXIS.
INSTABILITY SHOULD BE SOMEWHAT TEMPERED WITH LOSS OF DEEPER SFC
BASED INSTABILITY BY THIS TIME HOWEVER...BUT ENOUGH ELEVATED
INSTABILITY SHOULD PERSIST TO MAINTAIN AT LEAST CHANCE TSRA POPS
LATE THIS EVENING INTO THE EARLY PORTION OF THE OVERNIGHT.

NOT MUCH CHANGE TO FORECAST FOR SUNDAY...WITH ANOTHER STRONG
UPPER VORT MAX DIVING INTO THE SOUTHERN GREAT LAKES. A TROWAL-
LIKE FEATURE WILL ALSO BE WRAPPING ACROSS NORTHERN PORTIONS OF
THE AREA AND HAVE KEPT SPIRIT OF PREVIOUS FORECAST WITH HIGHEST
POPS ACROSS THE NORTH...AND HAVE JUST ADDED SOME TEMPORAL
RESOLUTION TO CAPTURE BEST FORCING LATE MORNING/EARLY
AFTERNOON...AND AS DRY SLOT SHIFTS SOUTH OF THE AREA. SOME ISO
THUNDER IS A POSSIBILITY...ESPECIALLY ACROSS THE NORTHEAST IN
ASSOCIATION WITH WEAK TROWAL.

&&

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014

A VERY QUIET LONG TERM PERIOD WITH HIGH PRESSURE BECOMING
ENTRENCHED ACROSS THE REGION FOR THE ENTIRE PERIOD. MONDAY WILL
BEGIN ON THE COOL SIDE WITH SOME GUIDANCE AND MIXING TOOLS
SUGGESTING HIGH TEMPS NOT GETTING OUT OF THE 50S. WITH FULL SUN
EXPECTED THINK WE WILL SEE SUPERADIABATIC LAPSE RATES NEAR
SURFACE AIDED BY STILL WARM GROUND OF LATE SUMMER. HAVE USED
SUPERBLEND TO COME UP WITH LOWER 60S NORTH AND MIDDLE 60S SOUTH.
REMAINDER OF THE PERIOD TO SEE A SLOW WARMING TREND WITH HIGHS
EACH DAY A FEW DEGREES WARMER WITH MODERATING AIR AND RISING
HEIGHTS. HIGHS SHOULD RETURN TO THE LOWER 70S BY MID WEEK AND
MIDDLE 70S BY THE END. WITH SUBSIDENCE AND HIGH PRESSURE DIRECTLY
OVERHEAD SHOULD SEE SKIES REMAINING MOSTLY CLEAR THROUGH THE
WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 154 AM EDT SUN SEP 21 2014

THORNY NR TERM W/CURRENT VARIABLE CIGS IN PLACE AND TAIL END OF
NEARING LINE OF STG STORMS ALG SHARP SFC CDFNT OVR CHICAGO.
WANING WAA WING AHD OF THIS FTR STILL FESTERING OVR ERN AREAS BUT
MOST SIG IMMEDIATE SHRA THREAT LOOKS TO PASS NR OR JUST SOUTH OF
KFWA. OTRWS GIVEN PROXIMITY OF UPSTREAM CONV LINE TO KSBN AND
RAPID SEWD MOVEMENT WILL ROLL W/A BRIEF TEMPO MENTION TO ELUCIDATE
WIND GUST POTENTIAL. THIS MAY SURVIVE EVEN TO KFWA BUT OPTED TO
LEAVE MENTION OUT AND AMEND AS NECESSARY GIVEN WANING ELEVATED
INSTABILITY POOL.

OTRWS STG UPSTREAM CAA WING WILL RAPIDLY DRIVE SEWD THROUGH DAYBREAK
W/STG MIXING DVLPG BY MID MORNING AND CONTG THROUGH AFTN. NWRLY SFC
GUSTS AOA 25KTS XPCD AT BOTH TERMINALS.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...MURPHY
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 210555
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
155 AM EDT SUN SEP 21 2014

.SYNOPSIS...
ISSUED AT 745 PM EDT SAT SEP 20 2014

AN UPPER LEVEL DISTURBANCE AND COLD FRONTAL BOUNDARY PRODUCED
SHOWERS AND THUNDERSTORMS SATURDAY EVENING. THE COVERAGE AND
INTENSITY WILL DIMINISH OVERNIGHT. ANOTHER UPPER LEVEL DISTURBANCE
WILL BRING ANOTHER CHANCE OF SHOWERS ON SUNDAY...WITH EVEN AN
ISOLATED THUNDERSTORM NEAR THE MICHIGAN...OHIO AND INDIANA BORDER
REGION. THEN CONDITIONS WILL DRY OUT SUNDAY NIGHT AS A RIDGE OF
HIGH PRESSURE BUILDS INTO THE AREA THROUGH THE EARLY PARTS OF NEXT
WEEK. LOW TONIGHT WILL DROP INTO THE LOWER 60S AND HIGHS ON SUNDAY
WILL BE COOLER...IN THE MID 60S TO LOWER 70S.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014

MAIN FORECAST CONCERN WILL BE SEVERE WEATHER POTENTIAL THIS
EVENING.

A STRONG UPPER VORT MAX TRACKING ACROSS NORTHWEST ILLINOIS AT
THIS TIME WILL BE THE PRIMARY SYNOPTIC FEATURE OF INTEREST THIS
EVENING. THIS SHORT WAVE HAS AN IMPRESSIVE WATER VAPOR
PRESENTATION...WITH A VERY SHARP UPPER LEVEL MOISTURE
DISCONTINUITY. MOST VIGOROUS CONVECTION AT THE PRESENT TIME HAS
DEVELOPED ACROSS NORTHEAST ILLINOIS AND ABOUT TO ENTER FAR WEST
CENTRAL PORTIONS OF IWX FORECAST AREA. DEEP LAYER SHEAR WILL
CONTINUE TO STRENGTHEN THROUGH THE REMAINDER OF THE
AFTERNOON/EARLY EVENING...WITH 0-3KM SHEAR VALUES ALSO INCREASING
INTO THE 35 TO 40 KNOT RANGE. THIS SHOULD HELP TO SUSTAIN WIND
THREAT INTO WESTERN PORTIONS OF THE AREA AND BALANCE COLD POOL
STRENGTH. STORMS SHOULD EVENTUALLY BEGIN TO OUTRUN MOST
PRONOUNCED INSTABILITY AXIS ACROSS NORTHEAST ILLINOIS/NORTHWEST
INDIANA WHERE 100 HPA MLCAPES ON THE ORDER OF 750-1500 J/KG ARE
EXPECTED. THIS MAY TEND TO DIMINISH STORM INTENSITY ACROSS
EASTERN HALF OR EASTERN THIRD OF THE AREA LATER THIS EVENING.
WHILE DAMAGING WIND IS THE MAIN THREAT...A FEW INSTANCES OF LARGE
HAIL WILL BE POSSIBLE WITH THE STRONGER CORES.

WHILE STRONGEST STORMS MAY TEND TO DIMINISH ACROSS EASTERN
PORTIONS OF THE AREA LATER THIS EVENING...PASSAGE OF PRIMARY
UPPER VORT MAX ACROSS NORTHWEST ILLINOIS LATER TONIGHT WILL BE
ACCOMPANIED BY SECONDARY LOW LEVEL MOISTURE POOLING AXIS.
INSTABILITY SHOULD BE SOMEWHAT TEMPERED WITH LOSS OF DEEPER SFC
BASED INSTABILITY BY THIS TIME HOWEVER...BUT ENOUGH ELEVATED
INSTABILITY SHOULD PERSIST TO MAINTAIN AT LEAST CHANCE TSRA POPS
LATE THIS EVENING INTO THE EARLY PORTION OF THE OVERNIGHT.

NOT MUCH CHANGE TO FORECAST FOR SUNDAY...WITH ANOTHER STRONG
UPPER VORT MAX DIVING INTO THE SOUTHERN GREAT LAKES. A TROWAL-
LIKE FEATURE WILL ALSO BE WRAPPING ACROSS NORTHERN PORTIONS OF
THE AREA AND HAVE KEPT SPIRIT OF PREVIOUS FORECAST WITH HIGHEST
POPS ACROSS THE NORTH...AND HAVE JUST ADDED SOME TEMPORAL
RESOLUTION TO CAPTURE BEST FORCING LATE MORNING/EARLY
AFTERNOON...AND AS DRY SLOT SHIFTS SOUTH OF THE AREA. SOME ISO
THUNDER IS A POSSIBILITY...ESPECIALLY ACROSS THE NORTHEAST IN
ASSOCIATION WITH WEAK TROWAL.

&&

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014

A VERY QUIET LONG TERM PERIOD WITH HIGH PRESSURE BECOMING
ENTRENCHED ACROSS THE REGION FOR THE ENTIRE PERIOD. MONDAY WILL
BEGIN ON THE COOL SIDE WITH SOME GUIDANCE AND MIXING TOOLS
SUGGESTING HIGH TEMPS NOT GETTING OUT OF THE 50S. WITH FULL SUN
EXPECTED THINK WE WILL SEE SUPERADIABATIC LAPSE RATES NEAR
SURFACE AIDED BY STILL WARM GROUND OF LATE SUMMER. HAVE USED
SUPERBLEND TO COME UP WITH LOWER 60S NORTH AND MIDDLE 60S SOUTH.
REMAINDER OF THE PERIOD TO SEE A SLOW WARMING TREND WITH HIGHS
EACH DAY A FEW DEGREES WARMER WITH MODERATING AIR AND RISING
HEIGHTS. HIGHS SHOULD RETURN TO THE LOWER 70S BY MID WEEK AND
MIDDLE 70S BY THE END. WITH SUBSIDENCE AND HIGH PRESSURE DIRECTLY
OVERHEAD SHOULD SEE SKIES REMAINING MOSTLY CLEAR THROUGH THE
WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 154 AM EDT SUN SEP 21 2014

THORNY NR TERM W/CURRENT VARIABLE CIGS IN PLACE AND TAIL END OF
NEARING LINE OF STG STORMS ALG SHARP SFC CDFNT OVR CHICAGO.
WANING WAA WING AHD OF THIS FTR STILL FESTERING OVR ERN AREAS BUT
MOST SIG IMMEDIATE SHRA THREAT LOOKS TO PASS NR OR JUST SOUTH OF
KFWA. OTRWS GIVEN PROXIMITY OF UPSTREAM CONV LINE TO KSBN AND
RAPID SEWD MOVEMENT WILL ROLL W/A BRIEF TEMPO MENTION TO ELUCIDATE
WIND GUST POTENTIAL. THIS MAY SURVIVE EVEN TO KFWA BUT OPTED TO
LEAVE MENTION OUT AND AMEND AS NECESSARY GIVEN WANING ELEVATED
INSTABILITY POOL.

OTRWS STG UPSTREAM CAA WING WILL RAPIDLY DRIVE SEWD THROUGH DAYBREAK
W/STG MIXING DVLPG BY MID MORNING AND CONTG THROUGH AFTN. NWRLY SFC
GUSTS AOA 25KTS XPCD AT BOTH TERMINALS.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...MURPHY
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 210014
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
814 PM EDT SAT SEP 20 2014

.SYNOPSIS...
ISSUED AT 745 PM EDT SAT SEP 20 2014

AN UPPER LEVEL DISTURBANCE AND COLD FRONTAL BOUNDARY PRODUCED
SHOWERS AND THUNDERSTORMS SATURDAY EVENING. THE COVERAGE AND
INTENSITY WILL DIMINISH OVERNIGHT. ANOTHER UPPER LEVEL DISTURBANCE
WILL BRING ANOTHER CHANCE OF SHOWERS ON SUNDAY...WITH EVEN AN
ISOLATED THUNDERSTORM NEAR THE MICHIGAN...OHIO AND INDIANA BORDER
REGION. THEN CONDITIONS WILL DRY OUT SUNDAY NIGHT AS A RIDGE OF
HIGH PRESSURE BUILDS INTO THE AREA THROUGH THE EARLY PARTS OF NEXT
WEEK. LOW TONIGHT WILL DROP INTO THE LOWER 60S AND HIGHS ON SUNDAY
WILL BE COOLER...IN THE MID 60S TO LOWER 70S.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014

MAIN FORECAST CONCERN WILL BE SEVERE WEATHER POTENTIAL THIS
EVENING.

A STRONG UPPER VORT MAX TRACKING ACROSS NORTHWEST ILLINOIS AT
THIS TIME WILL BE THE PRIMARY SYNOPTIC FEATURE OF INTEREST THIS
EVENING. THIS SHORT WAVE HAS AN IMPRESSIVE WATER VAPOR
PRESENTATION...WITH A VERY SHARP UPPER LEVEL MOISTURE
DISCONTINUITY. MOST VIGOROUS CONVECTION AT THE PRESENT TIME HAS
DEVELOPED ACROSS NORTHEAST ILLINOIS AND ABOUT TO ENTER FAR WEST
CENTRAL PORTIONS OF IWX FORECAST AREA. DEEP LAYER SHEAR WILL
CONTINUE TO STRENGTHEN THROUGH THE REMAINDER OF THE
AFTERNOON/EARLY EVENING...WITH 0-3KM SHEAR VALUES ALSO INCREASING
INTO THE 35 TO 40 KNOT RANGE. THIS SHOULD HELP TO SUSTAIN WIND
THREAT INTO WESTERN PORTIONS OF THE AREA AND BALANCE COLD POOL
STRENGTH. STORMS SHOULD EVENTUALLY BEGIN TO OUTRUN MOST
PRONOUNCED INSTABILITY AXIS ACROSS NORTHEAST ILLINOIS/NORTHWEST
INDIANA WHERE 100 HPA MLCAPES ON THE ORDER OF 750-1500 J/KG ARE
EXPECTED. THIS MAY TEND TO DIMINISH STORM INTENSITY ACROSS
EASTERN HALF OR EASTERN THIRD OF THE AREA LATER THIS EVENING.
WHILE DAMAGING WIND IS THE MAIN THREAT...A FEW INSTANCES OF LARGE
HAIL WILL BE POSSIBLE WITH THE STRONGER CORES.

WHILE STRONGEST STORMS MAY TEND TO DIMINISH ACROSS EASTERN
PORTIONS OF THE AREA LATER THIS EVENING...PASSAGE OF PRIMARY
UPPER VORT MAX ACROSS NORTHWEST ILLINOIS LATER TONIGHT WILL BE
ACCOMPANIED BY SECONDARY LOW LEVEL MOISTURE POOLING AXIS.
INSTABILITY SHOULD BE SOMEWHAT TEMPERED WITH LOSS OF DEEPER SFC
BASED INSTABILITY BY THIS TIME HOWEVER...BUT ENOUGH ELEVATED
INSTABILITY SHOULD PERSIST TO MAINTAIN AT LEAST CHANCE TSRA POPS
LATE THIS EVENING INTO THE EARLY PORTION OF THE OVERNIGHT.

NOT MUCH CHANGE TO FORECAST FOR SUNDAY...WITH ANOTHER STRONG
UPPER VORT MAX DIVING INTO THE SOUTHERN GREAT LAKES. A TROWAL-
LIKE FEATURE WILL ALSO BE WRAPPING ACROSS NORTHERN PORTIONS OF
THE AREA AND HAVE KEPT SPIRIT OF PREVIOUS FORECAST WITH HIGHEST
POPS ACROSS THE NORTH...AND HAVE JUST ADDED SOME TEMPORAL
RESOLUTION TO CAPTURE BEST FORCING LATE MORNING/EARLY
AFTERNOON...AND AS DRY SLOT SHIFTS SOUTH OF THE AREA. SOME ISO
THUNDER IS A POSSIBILITY...ESPECIALLY ACROSS THE NORTHEAST IN
ASSOCIATION WITH WEAK TROWAL.

&&

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014

A VERY QUIET LONG TERM PERIOD WITH HIGH PRESSURE BECOMING
ENTRENCHED ACROSS THE REGION FOR THE ENTIRE PERIOD. MONDAY WILL
BEGIN ON THE COOL SIDE WITH SOME GUIDANCE AND MIXING TOOLS
SUGGESTING HIGH TEMPS NOT GETTING OUT OF THE 50S. WITH FULL SUN
EXPECTED THINK WE WILL SEE SUPERADIABATIC LAPSE RATES NEAR
SURFACE AIDED BY STILL WARM GROUND OF LATE SUMMER. HAVE USED
SUPERBLEND TO COME UP WITH LOWER 60S NORTH AND MIDDLE 60S SOUTH.
REMAINDER OF THE PERIOD TO SEE A SLOW WARMING TREND WITH HIGHS
EACH DAY A FEW DEGREES WARMER WITH MODERATING AIR AND RISING
HEIGHTS. HIGHS SHOULD RETURN TO THE LOWER 70S BY MID WEEK AND
MIDDLE 70S BY THE END. WITH SUBSIDENCE AND HIGH PRESSURE DIRECTLY
OVERHEAD SHOULD SEE SKIES REMAINING MOSTLY CLEAR THROUGH THE
WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 745 PM EDT SAT SEP 20 2014

GROWING CONCERN FOR FUELING/ALTERNATE CONDITIONS DEVELOPING NEAR
DAYBREAK. AMID HIGHLY PERTURBED AND MOIST NEAR BOUNDARY LAYER
REGION WILL LEAD TO LOW STRATUS PRODUCTION AS POST FRONTAL
WESTERLY FLOW INCREASES. LIFTING BASES INTO LOW END VFR CIGS BY
LATE MORNING AS T/TD DEPRESSION INCREASE WITH SIGNIFICANT NEAR
SURFACE DRY AIR ADVECTION. LOW POINT CHANCES FOR SHRA MIDDAY INTO
SUNDAY AFTERNOON WITH BASE OF MID TROPOSPHERIC TROF SETTLING INTO
MI THUMB THROUGH NRN INDIANA...AND WILL FORGO MENTION ATTM.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ043-046.

     SMALL CRAFT ADVISORY FROM 8 AM SUNDAY TO 11 AM EDT MONDAY FOR
     LMZ043-046.

&&

$$

SYNOPSIS...MURPHY
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA










000
FXUS63 KIWX 210014
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
814 PM EDT SAT SEP 20 2014

.SYNOPSIS...
ISSUED AT 745 PM EDT SAT SEP 20 2014

AN UPPER LEVEL DISTURBANCE AND COLD FRONTAL BOUNDARY PRODUCED
SHOWERS AND THUNDERSTORMS SATURDAY EVENING. THE COVERAGE AND
INTENSITY WILL DIMINISH OVERNIGHT. ANOTHER UPPER LEVEL DISTURBANCE
WILL BRING ANOTHER CHANCE OF SHOWERS ON SUNDAY...WITH EVEN AN
ISOLATED THUNDERSTORM NEAR THE MICHIGAN...OHIO AND INDIANA BORDER
REGION. THEN CONDITIONS WILL DRY OUT SUNDAY NIGHT AS A RIDGE OF
HIGH PRESSURE BUILDS INTO THE AREA THROUGH THE EARLY PARTS OF NEXT
WEEK. LOW TONIGHT WILL DROP INTO THE LOWER 60S AND HIGHS ON SUNDAY
WILL BE COOLER...IN THE MID 60S TO LOWER 70S.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014

MAIN FORECAST CONCERN WILL BE SEVERE WEATHER POTENTIAL THIS
EVENING.

A STRONG UPPER VORT MAX TRACKING ACROSS NORTHWEST ILLINOIS AT
THIS TIME WILL BE THE PRIMARY SYNOPTIC FEATURE OF INTEREST THIS
EVENING. THIS SHORT WAVE HAS AN IMPRESSIVE WATER VAPOR
PRESENTATION...WITH A VERY SHARP UPPER LEVEL MOISTURE
DISCONTINUITY. MOST VIGOROUS CONVECTION AT THE PRESENT TIME HAS
DEVELOPED ACROSS NORTHEAST ILLINOIS AND ABOUT TO ENTER FAR WEST
CENTRAL PORTIONS OF IWX FORECAST AREA. DEEP LAYER SHEAR WILL
CONTINUE TO STRENGTHEN THROUGH THE REMAINDER OF THE
AFTERNOON/EARLY EVENING...WITH 0-3KM SHEAR VALUES ALSO INCREASING
INTO THE 35 TO 40 KNOT RANGE. THIS SHOULD HELP TO SUSTAIN WIND
THREAT INTO WESTERN PORTIONS OF THE AREA AND BALANCE COLD POOL
STRENGTH. STORMS SHOULD EVENTUALLY BEGIN TO OUTRUN MOST
PRONOUNCED INSTABILITY AXIS ACROSS NORTHEAST ILLINOIS/NORTHWEST
INDIANA WHERE 100 HPA MLCAPES ON THE ORDER OF 750-1500 J/KG ARE
EXPECTED. THIS MAY TEND TO DIMINISH STORM INTENSITY ACROSS
EASTERN HALF OR EASTERN THIRD OF THE AREA LATER THIS EVENING.
WHILE DAMAGING WIND IS THE MAIN THREAT...A FEW INSTANCES OF LARGE
HAIL WILL BE POSSIBLE WITH THE STRONGER CORES.

WHILE STRONGEST STORMS MAY TEND TO DIMINISH ACROSS EASTERN
PORTIONS OF THE AREA LATER THIS EVENING...PASSAGE OF PRIMARY
UPPER VORT MAX ACROSS NORTHWEST ILLINOIS LATER TONIGHT WILL BE
ACCOMPANIED BY SECONDARY LOW LEVEL MOISTURE POOLING AXIS.
INSTABILITY SHOULD BE SOMEWHAT TEMPERED WITH LOSS OF DEEPER SFC
BASED INSTABILITY BY THIS TIME HOWEVER...BUT ENOUGH ELEVATED
INSTABILITY SHOULD PERSIST TO MAINTAIN AT LEAST CHANCE TSRA POPS
LATE THIS EVENING INTO THE EARLY PORTION OF THE OVERNIGHT.

NOT MUCH CHANGE TO FORECAST FOR SUNDAY...WITH ANOTHER STRONG
UPPER VORT MAX DIVING INTO THE SOUTHERN GREAT LAKES. A TROWAL-
LIKE FEATURE WILL ALSO BE WRAPPING ACROSS NORTHERN PORTIONS OF
THE AREA AND HAVE KEPT SPIRIT OF PREVIOUS FORECAST WITH HIGHEST
POPS ACROSS THE NORTH...AND HAVE JUST ADDED SOME TEMPORAL
RESOLUTION TO CAPTURE BEST FORCING LATE MORNING/EARLY
AFTERNOON...AND AS DRY SLOT SHIFTS SOUTH OF THE AREA. SOME ISO
THUNDER IS A POSSIBILITY...ESPECIALLY ACROSS THE NORTHEAST IN
ASSOCIATION WITH WEAK TROWAL.

&&

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014

A VERY QUIET LONG TERM PERIOD WITH HIGH PRESSURE BECOMING
ENTRENCHED ACROSS THE REGION FOR THE ENTIRE PERIOD. MONDAY WILL
BEGIN ON THE COOL SIDE WITH SOME GUIDANCE AND MIXING TOOLS
SUGGESTING HIGH TEMPS NOT GETTING OUT OF THE 50S. WITH FULL SUN
EXPECTED THINK WE WILL SEE SUPERADIABATIC LAPSE RATES NEAR
SURFACE AIDED BY STILL WARM GROUND OF LATE SUMMER. HAVE USED
SUPERBLEND TO COME UP WITH LOWER 60S NORTH AND MIDDLE 60S SOUTH.
REMAINDER OF THE PERIOD TO SEE A SLOW WARMING TREND WITH HIGHS
EACH DAY A FEW DEGREES WARMER WITH MODERATING AIR AND RISING
HEIGHTS. HIGHS SHOULD RETURN TO THE LOWER 70S BY MID WEEK AND
MIDDLE 70S BY THE END. WITH SUBSIDENCE AND HIGH PRESSURE DIRECTLY
OVERHEAD SHOULD SEE SKIES REMAINING MOSTLY CLEAR THROUGH THE
WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 745 PM EDT SAT SEP 20 2014

GROWING CONCERN FOR FUELING/ALTERNATE CONDITIONS DEVELOPING NEAR
DAYBREAK. AMID HIGHLY PERTURBED AND MOIST NEAR BOUNDARY LAYER
REGION WILL LEAD TO LOW STRATUS PRODUCTION AS POST FRONTAL
WESTERLY FLOW INCREASES. LIFTING BASES INTO LOW END VFR CIGS BY
LATE MORNING AS T/TD DEPRESSION INCREASE WITH SIGNIFICANT NEAR
SURFACE DRY AIR ADVECTION. LOW POINT CHANCES FOR SHRA MIDDAY INTO
SUNDAY AFTERNOON WITH BASE OF MID TROPOSPHERIC TROF SETTLING INTO
MI THUMB THROUGH NRN INDIANA...AND WILL FORGO MENTION ATTM.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ043-046.

     SMALL CRAFT ADVISORY FROM 8 AM SUNDAY TO 11 AM EDT MONDAY FOR
     LMZ043-046.

&&

$$

SYNOPSIS...MURPHY
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA











000
FXUS63 KIWX 202037
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
437 PM EDT SAT SEP 20 2014

.SYNOPSIS...
ISSUED AT 428 PM EDT SAT SEP 20 2014

AN UPPER LEVEL DISTURBANCE AND COLD FRONTAL BOUNDARY WILL PRODUCE
A LIKELIHOOD OF SHOWERS AND THUNDERSTORMS THIS EVENING...GRADUALLY
DIMINISHING IN COVERAGE OVERNIGHT. ANOTHER UPPER LEVEL DISTURBANCE
WILL BRING A CONTINUED CHANCE OF SHOWERS AND ISOLATED
THUNDERSTORMS ON SUNDAY...WITH CONDITIONS DRYING SUNDAY NIGHT AS A
RIDGE OF HIGH PRESSURE BUILDS INTO THE AREA THROUGH THE EARLY
PARTS OF NEXT WEEK.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014

MAIN FORECAST CONCERN WILL BE SEVERE WEATHER POTENTIAL THIS EVENING.

A STRONG UPPER VORT MAX TRACKING ACROSS NORTHWEST ILLINOIS AT THIS
TIME WILL BE THE PRIMARY SYNOPTIC FEATURE OF INTEREST THIS EVENING.
THIS SHORT WAVE HAS AN IMPRESSIVE WATER VAPOR PRESENTATION...WITH A
VERY SHARP UPPER LEVEL MOISTURE DISCONTINUITY. MOST VIGOROUS
CONVECTION AT THE PRESENT TIME HAS DEVELOPED ACROSS NORTHEAST
ILLINOIS AND ABOUT TO ENTER FAR WEST CENTRAL PORTIONS OF IWX
FORECAST AREA. DEEP LAYER SHEAR WILL CONTINUE TO STRENGTHEN THROUGH
THE REMAINDER OF THE AFTERNOON/EARLY EVENING...WITH 0-3KM SHEAR
VALUES ALSO INCREASING INTO THE 35 TO 40 KNOT RANGE. THIS SHOULD
HELP TO SUSTAIN WIND THREAT INTO WESTERN PORTIONS OF THE AREA AND
BALANCE COLD POOL STRENGTH. STORMS SHOULD EVENTUALLY BEGIN TO
OUTRUN MOST PRONOUNCED INSTABILITY AXIS ACROSS NORTHEAST
ILLINOIS/NORTHWEST INDIANA WHERE 100 HPA MLCAPES ON THE ORDER OF
750-1500 J/KG ARE EXPECTED. THIS MAY TEND TO DIMINISH STORM
INTENSITY ACROSS EASTERN HALF OR EASTERN THIRD OF THE AREA LATER
THIS EVENING. WHILE DAMAGING WIND IS THE MAIN THREAT...A FEW
INSTANCES OF LARGE HAIL WILL BE POSSIBLE WITH THE STRONGER CORES.

WHILE STRONGEST STORMS MAY TEND TO DIMINISH ACROSS EASTERN PORTIONS
OF THE AREA LATER THIS EVENING...PASSAGE OF PRIMARY UPPER VORT MAX
ACROSS NORTHWEST ILLINOIS LATER TONIGHT WILL BE ACCOMPANIED BY
SECONDARY LOW LEVEL MOISTURE POOLING AXIS. INSTABILITY SHOULD BE
SOMEWHAT TEMPERED WITH LOSS OF DEEPER SFC BASED INSTABILITY BY
THIS TIME HOWEVER...BUT ENOUGH ELEVATED INSTABILITY SHOULD PERSIST
TO MAINTAIN AT LEAST CHANCE TSRA POPS LATE THIS EVENING INTO THE
EARLY PORTION OF THE OVERNIGHT.

NOT MUCH CHANGE TO FORECAST FOR SUNDAY...WITH ANOTHER STRONG UPPER
VORT MAX DIVING INTO THE SOUTHERN GREAT LAKES. A TROWAL-LIKE FEATURE
WILL ALSO BE WRAPPING ACROSS NORTHERN PORTIONS OF THE AREA AND HAVE
KEPT SPIRIT OF PREVIOUS FORECAST WITH HIGHEST POPS ACROSS THE
NORTH...AND HAVE JUST ADDED SOME TEMPORAL RESOLUTION TO CAPTURE BEST
FORCING LATE MORNING/EARLY AFTERNOON...AND AS DRY SLOT SHIFTS
SOUTH OF THE AREA. SOME ISO THUNDER IS A POSSIBILITY...ESPECIALLY
ACROSS THE NORTHEAST IN ASSOCIATION WITH WEAK TROWAL.

&&

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014


A VERY QUIET LONG TERM PERIOD WITH HIGH PRESSURE BECOMING ENTRENCHED
ACROSS THE REGION FOR THE ENTIRE PERIOD. MONDAY WILL BEGIN ON THE
COOL SIDE WITH SOME GUIDANCE AND MIXING TOOLS SUGGESTING HIGH TEMPS
NOT GETTING OUT OF THE 50S. WITH FULL SUN EXPECTED THINK WE WILL SEE
SUPERADIABATIC LAPSE RATES NEAR SURFACE AIDED BY STILL WARM GROUND OF
LATE SUMMER. HAVE USED SUPERBLEND TO COME UP WITH LOWER 60S NORTH
AND MIDDLE 60S SOUTH. REMAINDER OF THE PERIOD TO SEE A SLOW WARMING
TREND WITH HIGHS EACH DAY A FEW DEGREES WARMER WITH MODERATING AIR
AND RISING HEIGHTS. HIGHS SHOULD RETURN TO THE LOWER 70S BY MID WEEK
AND MIDDLE 70S BY THE END. WITH SUBSIDENCE AND HIGH PRESSURE
DIRECTLY OVERHEAD SHOULD SEE SKIES REMAINING MOSTLY CLEAR THROUGH
THE WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 139 PM EDT SAT SEP 20 2014

SCATTERED SHOWERS AND THUNDERSTORMS ARE BEGINNING TO INCREASE IN
COVERAGE EARLY THIS AFTERNOON ACROSS EASTERN IOWA AND NORTHERN
ILLINOIS...JUST DOWNSTREAM OF A WELL PRONOUNCED UPPER LEVEL WAVE
ACROSS EASTERN IOWA. PRIMARY INSTABILITY AXIS SITUATED ACROSS
NORTHERN ILLINOIS SHOULD SHIFT INTO NORTHWEST AND PORTIONS OF
NORTH CENTRAL INDIANA LATE THIS AFTERNOON INTO EARLY THIS EVENING.
SHOULD CONTINUE TO SEE COVERAGE OF SHOWERS AND THUNDERSTORMS
EXPAND ACROSS NORTHEAST ILLINOIS OVER NEXT SEVERAL HOURS...AND
HAVE INTRODUCED TEMPO TSRA MENTION AT KSBN FROM 21Z TO 00Z.
EASTWARD EXTENT OF INSTABILITY MAY BE MORE QUESTIONABLE FOR
THUNDER BUT GIVEN STRENGTH OF UPPER FORCING...PROSPECTS OF THUNDER
AT KFWA APPEAR TO BE INCREASING FOR THIS EVENING. WITH STILL SOME
LOWER CONFIDENCE HOW INSTABILITY FIELDS WILL EVOLVE THIS
AFTERNOON...HAVE LIMITED THUNDER MENTION TO VCTS THIS EVENING AT
KFWA...BUT WILL CERTAINLY NEED TO MONITOR FOR POSSIBLE INCLUSION.
SECONDARY UPPER WAVE ACROSS THE UPPER MIDWEST TO DROP INTO THE
SOUTHERN GREAT LAKES OVERNIGHT KEEPING THE PROSPECTS OF SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS GOING. WIND SHIFT TO THE WEST
EXPECTED EARLY SUNDAY MORNING WITH FRONTAL PASSAGE...WITH WEST
WINDS BECOMING MORE GUSTY IN NATURE TOWARD THE END OF THIS FORECAST
VALID PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ043-046.

     SMALL CRAFT ADVISORY FROM 8 AM SUNDAY TO 11 AM EDT MONDAY FOR
     LMZ043-046.

&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 202037
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
437 PM EDT SAT SEP 20 2014

.SYNOPSIS...
ISSUED AT 428 PM EDT SAT SEP 20 2014

AN UPPER LEVEL DISTURBANCE AND COLD FRONTAL BOUNDARY WILL PRODUCE
A LIKELIHOOD OF SHOWERS AND THUNDERSTORMS THIS EVENING...GRADUALLY
DIMINISHING IN COVERAGE OVERNIGHT. ANOTHER UPPER LEVEL DISTURBANCE
WILL BRING A CONTINUED CHANCE OF SHOWERS AND ISOLATED
THUNDERSTORMS ON SUNDAY...WITH CONDITIONS DRYING SUNDAY NIGHT AS A
RIDGE OF HIGH PRESSURE BUILDS INTO THE AREA THROUGH THE EARLY
PARTS OF NEXT WEEK.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014

MAIN FORECAST CONCERN WILL BE SEVERE WEATHER POTENTIAL THIS EVENING.

A STRONG UPPER VORT MAX TRACKING ACROSS NORTHWEST ILLINOIS AT THIS
TIME WILL BE THE PRIMARY SYNOPTIC FEATURE OF INTEREST THIS EVENING.
THIS SHORT WAVE HAS AN IMPRESSIVE WATER VAPOR PRESENTATION...WITH A
VERY SHARP UPPER LEVEL MOISTURE DISCONTINUITY. MOST VIGOROUS
CONVECTION AT THE PRESENT TIME HAS DEVELOPED ACROSS NORTHEAST
ILLINOIS AND ABOUT TO ENTER FAR WEST CENTRAL PORTIONS OF IWX
FORECAST AREA. DEEP LAYER SHEAR WILL CONTINUE TO STRENGTHEN THROUGH
THE REMAINDER OF THE AFTERNOON/EARLY EVENING...WITH 0-3KM SHEAR
VALUES ALSO INCREASING INTO THE 35 TO 40 KNOT RANGE. THIS SHOULD
HELP TO SUSTAIN WIND THREAT INTO WESTERN PORTIONS OF THE AREA AND
BALANCE COLD POOL STRENGTH. STORMS SHOULD EVENTUALLY BEGIN TO
OUTRUN MOST PRONOUNCED INSTABILITY AXIS ACROSS NORTHEAST
ILLINOIS/NORTHWEST INDIANA WHERE 100 HPA MLCAPES ON THE ORDER OF
750-1500 J/KG ARE EXPECTED. THIS MAY TEND TO DIMINISH STORM
INTENSITY ACROSS EASTERN HALF OR EASTERN THIRD OF THE AREA LATER
THIS EVENING. WHILE DAMAGING WIND IS THE MAIN THREAT...A FEW
INSTANCES OF LARGE HAIL WILL BE POSSIBLE WITH THE STRONGER CORES.

WHILE STRONGEST STORMS MAY TEND TO DIMINISH ACROSS EASTERN PORTIONS
OF THE AREA LATER THIS EVENING...PASSAGE OF PRIMARY UPPER VORT MAX
ACROSS NORTHWEST ILLINOIS LATER TONIGHT WILL BE ACCOMPANIED BY
SECONDARY LOW LEVEL MOISTURE POOLING AXIS. INSTABILITY SHOULD BE
SOMEWHAT TEMPERED WITH LOSS OF DEEPER SFC BASED INSTABILITY BY
THIS TIME HOWEVER...BUT ENOUGH ELEVATED INSTABILITY SHOULD PERSIST
TO MAINTAIN AT LEAST CHANCE TSRA POPS LATE THIS EVENING INTO THE
EARLY PORTION OF THE OVERNIGHT.

NOT MUCH CHANGE TO FORECAST FOR SUNDAY...WITH ANOTHER STRONG UPPER
VORT MAX DIVING INTO THE SOUTHERN GREAT LAKES. A TROWAL-LIKE FEATURE
WILL ALSO BE WRAPPING ACROSS NORTHERN PORTIONS OF THE AREA AND HAVE
KEPT SPIRIT OF PREVIOUS FORECAST WITH HIGHEST POPS ACROSS THE
NORTH...AND HAVE JUST ADDED SOME TEMPORAL RESOLUTION TO CAPTURE BEST
FORCING LATE MORNING/EARLY AFTERNOON...AND AS DRY SLOT SHIFTS
SOUTH OF THE AREA. SOME ISO THUNDER IS A POSSIBILITY...ESPECIALLY
ACROSS THE NORTHEAST IN ASSOCIATION WITH WEAK TROWAL.

&&

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 428 PM EDT SAT SEP 20 2014


A VERY QUIET LONG TERM PERIOD WITH HIGH PRESSURE BECOMING ENTRENCHED
ACROSS THE REGION FOR THE ENTIRE PERIOD. MONDAY WILL BEGIN ON THE
COOL SIDE WITH SOME GUIDANCE AND MIXING TOOLS SUGGESTING HIGH TEMPS
NOT GETTING OUT OF THE 50S. WITH FULL SUN EXPECTED THINK WE WILL SEE
SUPERADIABATIC LAPSE RATES NEAR SURFACE AIDED BY STILL WARM GROUND OF
LATE SUMMER. HAVE USED SUPERBLEND TO COME UP WITH LOWER 60S NORTH
AND MIDDLE 60S SOUTH. REMAINDER OF THE PERIOD TO SEE A SLOW WARMING
TREND WITH HIGHS EACH DAY A FEW DEGREES WARMER WITH MODERATING AIR
AND RISING HEIGHTS. HIGHS SHOULD RETURN TO THE LOWER 70S BY MID WEEK
AND MIDDLE 70S BY THE END. WITH SUBSIDENCE AND HIGH PRESSURE
DIRECTLY OVERHEAD SHOULD SEE SKIES REMAINING MOSTLY CLEAR THROUGH
THE WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 139 PM EDT SAT SEP 20 2014

SCATTERED SHOWERS AND THUNDERSTORMS ARE BEGINNING TO INCREASE IN
COVERAGE EARLY THIS AFTERNOON ACROSS EASTERN IOWA AND NORTHERN
ILLINOIS...JUST DOWNSTREAM OF A WELL PRONOUNCED UPPER LEVEL WAVE
ACROSS EASTERN IOWA. PRIMARY INSTABILITY AXIS SITUATED ACROSS
NORTHERN ILLINOIS SHOULD SHIFT INTO NORTHWEST AND PORTIONS OF
NORTH CENTRAL INDIANA LATE THIS AFTERNOON INTO EARLY THIS EVENING.
SHOULD CONTINUE TO SEE COVERAGE OF SHOWERS AND THUNDERSTORMS
EXPAND ACROSS NORTHEAST ILLINOIS OVER NEXT SEVERAL HOURS...AND
HAVE INTRODUCED TEMPO TSRA MENTION AT KSBN FROM 21Z TO 00Z.
EASTWARD EXTENT OF INSTABILITY MAY BE MORE QUESTIONABLE FOR
THUNDER BUT GIVEN STRENGTH OF UPPER FORCING...PROSPECTS OF THUNDER
AT KFWA APPEAR TO BE INCREASING FOR THIS EVENING. WITH STILL SOME
LOWER CONFIDENCE HOW INSTABILITY FIELDS WILL EVOLVE THIS
AFTERNOON...HAVE LIMITED THUNDER MENTION TO VCTS THIS EVENING AT
KFWA...BUT WILL CERTAINLY NEED TO MONITOR FOR POSSIBLE INCLUSION.
SECONDARY UPPER WAVE ACROSS THE UPPER MIDWEST TO DROP INTO THE
SOUTHERN GREAT LAKES OVERNIGHT KEEPING THE PROSPECTS OF SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS GOING. WIND SHIFT TO THE WEST
EXPECTED EARLY SUNDAY MORNING WITH FRONTAL PASSAGE...WITH WEST
WINDS BECOMING MORE GUSTY IN NATURE TOWARD THE END OF THIS FORECAST
VALID PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ043-046.

     SMALL CRAFT ADVISORY FROM 8 AM SUNDAY TO 11 AM EDT MONDAY FOR
     LMZ043-046.

&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 201758
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
158 PM EDT SAT SEP 20 2014

.SYNOPSIS...
ISSUED AT 339 AM EDT SAT SEP 20 2014

MILD AND BREEZY CONDITIONS WILL DEVELOP TODAY AHEAD OF A COLD
FRONT ADVANCING EASTWARD OUT OF THE PLAINS. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON AND
CONTINUE INTO THIS EVENING. HIGHS THIS AFTERNOON WILL TOP OUT IN
THE UPPER 70S TO LOWER 80S AS SOUTHWEST WINDS GUST UP TO 25 MPH
AT TIMES.

&&

.UPDATE...
ISSUED AT 1154 AM EDT SAT SEP 20 2014

PREVIOUS FORECAST APPEARS TO BE IN GOOD SHAPE WITH CONTINUED FOCUS
ON CONVECTIVE POTENTIAL THIS AFTERNOON. WESTERLY ORIENTED LOW
LEVEL JET WILL CONTINUE TO ADVECT LOW LEVEL THETAE RIDGE EASTWARD
ACROSS NORTHERN INDIANA THIS AFTERNOON. LOW LEVEL DEW POINTS
SHOULD STEADILY INCREASE INTO THE LOWER TO MID 60S THIS AFTERNOON
PARTICULARLY ACROSS WESTERN PORTIONS OF THE FORECAST AREA. THIS
SHOULD LEAD TO AN AXIS OF SURFACE BASED CAPE ON THE ORDER OF
750-1200 J/KG ACROSS WESTERN HALF OF THE AREA THIS AFTERNOON WITH
DEEP LAYER SHEAR INCREASING INTO THE 35 TO 40 KNOT RANGE. WATER
VAPOR IMAGERY IS DEPICTING NEXT SHORT WAVE OF INTEREST ACROSS
EASTERN IOWA AND THIS WILL BE THE FEATURE OF INTEREST TO TRACK
THROUGH EARLY THIS EVENING. AT LEAST A 2 TO 3 HOUR PERIOD OF
INSOLATION IS EXPECTED ACROSS THE AREA THIS AFTERNOON WHICH SHOULD
ALLOW ABOVE INSTABILITY MAGNITUDE TO BE REALIZED. WEAK CIN IS
POSSIBLE THROUGH LATE AFTERNOON BUT WITH EVENTUAL APPROACH OF
UPPER WAVE LATE THIS AFTERNOON ANY WEAK CIN SHOULD BE ERODED
ACROSS THE WEST. WITH FAIRLY STRONG FORCING AND ADEQUATE
SHEAR...MAINLY LIMITING FACTOR TO SEVERE POTENTIAL STILL APPEARS
TO BE INSTABILITY. STILL EXPECTING RISK TO BE MORE ISOLATED IN
NATURE GIVEN LOWER END INSTABILITY...BUT CANNOT RULE OUT POTENTIAL
OF SOME ISOLATED DAMAGING WIND GUSTS. THREAT SHOULD DIMINISH WITH
EASTWARD EXTENT WITH MORE LIMITED INSTABILITY ACROSS EXTREME
NORTHEAST INDIANA/NORTHWEST OHIO.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM EDT SAT SEP 20 2014

VIGOROUS LEAD SW TROUGH ACRS ERN ND IN ASSOCN W/LARGER SCALE
UPSTREAM DISTURBANCE DROPPING SEWD OUT OF ALBERTA SIGNALS
SIGNIFICANT HGT AMPLIFICATION ALOFT ACRS THE GREAT LAKES THROUGH
SUNDAY. PREFNTL WIND SHIFT IN ASSOCN/W LEAD DISTURBANCE ACTING UPON
A FVRBL RTN FLW LL THETA-E RIDGE TO THE WEST THIS MORNING FM NERN NE
NEWD INTO SERN MN. HWVR XPC THIS ACTIVITY WILL DECAY RATHER ABRUPTLY
EWD THROUGH DAYBREAK AS IT ENCOUNTERS A MUCH MORE STABLE AIRMASS.

PRIMARY SHRT TERM DIFFICULTY IS ACCESSING TEMPORAL EXTENT OF
PROBABLY CONVN LTR THIS AFTN INTO THIS EVE. 12Z GUIDANCE SIMILAR IN
SCOPE W/NARROWING EWD ADVTN OF PLAINS THETA-E PLUME. HIGHRES DETAILS
PER WIND SHIFT TIMING SUGGEST LTL THUNDER THREAT WILL CARRY EWD OF
THE I-69 CORRIDOR AS LL THETA-E RIDGE PINCHES OFF W/NEWD EXTENT AND
HAVE CUT LT AFTN/EVE POP EXTENT ACRS FAR SE FURTHER. OTRWS GIST OF
PREV FCST HOLD YET DID ADD FURTHER TEMPORAL DETAIL BASED ON
CONSENSUS OF PREFERRED HIGHRES GUIDANCE CLUSTERING. CONDITIONAL SVR
THREAT PREDICATED ON ATTAINING SUFFICIENT SFC BASED DESTABILIZATION
LT THIS AFTN W/AREAS WEST OF I-69 CORRIDOR AND SOUTH OF HIGHWAY 30
IN BEST OVERLAP OF 0-6KM SHEAR AND GREATER MODEL IMPLIED HEATING.
REGARDLESS DAMAGING WIND THREAT LOOKS TO REMAIN ISOLD AT BEST.

SFC CDFNT FOLLOWS BUT IN LIGHT OF DIGGING UPSTREAM DISTURBANCE SLWR
TIMING TWD DAYBREAK SUN...IT APPEARS QUITE UNFVRBL FOR ADDNL SHRA OR
TSRA UNTIL LTR SUN AM.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 336 AM EDT SAT SEP 20 2014

SHORTWAVE OF INTEREST WAS WELL DEPICTED ON WATER VAPOR LOOP ENTERING
SASKATCHEWAN AND DROPPING RAPIDLY SE. INCREASING LIFT ASSOCIATED
WITH THIS WAVE WILL BEGIN TO IMPACT THE AREA AS EARLY AS 12Z SUNDAY
WITH PEAK DEVELOPMENT LIKELY OCCURRING IN THE 17 TO 20Z TIME FRAME.
POCKET OF COLD AIR ALOFT (500 MB TEMPS -16 TO -20 C DEPENDING ON
MODEL OF CHOICE) WILL ACCOMPANY THE WAVE WITH TIMING ALSO IN
FAVORABLE EARLY AFTERNOON PERIOD. WHILE MUCH OF THE MOISTURE WILL
HAVE BEEN GUTTED...SFC DEWPOINTS WILL LIKELY STILL BE IN THE LOWER
TO MIDDLE 50S. THIS SHOULD YIELD SOME ELEVATED INSTABILITY WITH
SCATTERED SHOWERS (THUNDER??) LOOKING MORE LIKELY SUN MORNING INTO
MID AFTERNOON BEFORE THE WAVE SHIFTS EAST. HAVE INCREASED POPS
ACROSS NE HALF BUT HELD SHY OF LIKELY FOR NOW.

COLDEST AIR WILL QUICKLY SHIFT AWAY FROM THE REGION BY MONDAY
AFTERNOON WITH MODERATING TEMPERATURES BACK TO NEAR OR EVEN ABOVE
NORMAL AS DEEP TROUGH DIGS INTO THE WESTERN STATES AND REMAINS
PARKED THERE FOR THE FORESEEABLE FUTURE. THIS WILL ALLOW FOR A
LIKELY TRANQUIL WRAP UP TO SEPTEMBER WITH CHANCES FOR MEASURABLE
RAINFALL RATHER BLEAK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 139 PM EDT SAT SEP 20 2014

SCATTERED SHOWERS AND THUNDERSTORMS ARE BEGINNING TO INCREASE IN
COVERAGE EARLY THIS AFTERNOON ACROSS EASTERN IOWA AND NORTHERN
ILLINOIS...JUST DOWNSTREAM OF A WELL PRONOUNCED UPPER LEVEL WAVE
ACROSS EASTERN IOWA. PRIMARY INSTABILITY AXIS SITUATED ACROSS
NORTHERN ILLINOIS SHOULD SHIFT INTO NORTHWEST AND PORTIONS OF
NORTH CENTRAL INDIANA LATE THIS AFTERNOON INTO EARLY THIS EVENING.
SHOULD CONTINUE TO SEE COVERAGE OF SHOWERS AND THUNDERSTORMS
EXPAND ACROSS NORTHEAST ILLINOIS OVER NEXT SEVERAL HOURS...AND
HAVE INTRODUCED TEMPO TSRA MENTION AT KSBN FROM 21Z TO 00Z.
EASTWARD EXTENT OF INSTABILITY MAY BE MORE QUESTIONABLE FOR
THUNDER BUT GIVEN STRENGTH OF UPPER FORCING...PROSPECTS OF THUNDER
AT KFWA APPEAR TO BE INCREASING FOR THIS EVENING. WITH STILL SOME
LOWER CONFIDENCE HOW INSTABILITY FIELDS WILL EVOLVE THIS
AFTERNOON...HAVE LIMITED THUNDER MENTION TO VCTS THIS EVENING AT
KFWA...BUT WILL CERTAINLY NEED TO MONITOR FOR POSSIBLE INCLUSION.
SECONDARY UPPER WAVE ACROSS THE UPPER MIDWEST TO DROP INTO THE
SOUTHERN GREAT LAKES OVERNIGHT KEEPING THE PROSPECTS OF SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS GOING. WIND SHIFT TO THE WEST
EXPECTED EARLY SUNDAY MORNING WITH FRONTAL PASSAGE...WITH WEST
WINDS BECOMING MORE GUSTY IN NATURE TOWARD THE END OF THIS FORECAST
VALID PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043-
     046.

     SMALL CRAFT ADVISORY FROM 10 AM TO 8 PM EDT SUNDAY FOR LMZ043-
     046.

&&

$$

UPDATE...MARSILI
SYNOPSIS...LOTHAMER
SHORT TERM...T
LONG TERM...FISHER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 201758
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
158 PM EDT SAT SEP 20 2014

.SYNOPSIS...
ISSUED AT 339 AM EDT SAT SEP 20 2014

MILD AND BREEZY CONDITIONS WILL DEVELOP TODAY AHEAD OF A COLD
FRONT ADVANCING EASTWARD OUT OF THE PLAINS. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON AND
CONTINUE INTO THIS EVENING. HIGHS THIS AFTERNOON WILL TOP OUT IN
THE UPPER 70S TO LOWER 80S AS SOUTHWEST WINDS GUST UP TO 25 MPH
AT TIMES.

&&

.UPDATE...
ISSUED AT 1154 AM EDT SAT SEP 20 2014

PREVIOUS FORECAST APPEARS TO BE IN GOOD SHAPE WITH CONTINUED FOCUS
ON CONVECTIVE POTENTIAL THIS AFTERNOON. WESTERLY ORIENTED LOW
LEVEL JET WILL CONTINUE TO ADVECT LOW LEVEL THETAE RIDGE EASTWARD
ACROSS NORTHERN INDIANA THIS AFTERNOON. LOW LEVEL DEW POINTS
SHOULD STEADILY INCREASE INTO THE LOWER TO MID 60S THIS AFTERNOON
PARTICULARLY ACROSS WESTERN PORTIONS OF THE FORECAST AREA. THIS
SHOULD LEAD TO AN AXIS OF SURFACE BASED CAPE ON THE ORDER OF
750-1200 J/KG ACROSS WESTERN HALF OF THE AREA THIS AFTERNOON WITH
DEEP LAYER SHEAR INCREASING INTO THE 35 TO 40 KNOT RANGE. WATER
VAPOR IMAGERY IS DEPICTING NEXT SHORT WAVE OF INTEREST ACROSS
EASTERN IOWA AND THIS WILL BE THE FEATURE OF INTEREST TO TRACK
THROUGH EARLY THIS EVENING. AT LEAST A 2 TO 3 HOUR PERIOD OF
INSOLATION IS EXPECTED ACROSS THE AREA THIS AFTERNOON WHICH SHOULD
ALLOW ABOVE INSTABILITY MAGNITUDE TO BE REALIZED. WEAK CIN IS
POSSIBLE THROUGH LATE AFTERNOON BUT WITH EVENTUAL APPROACH OF
UPPER WAVE LATE THIS AFTERNOON ANY WEAK CIN SHOULD BE ERODED
ACROSS THE WEST. WITH FAIRLY STRONG FORCING AND ADEQUATE
SHEAR...MAINLY LIMITING FACTOR TO SEVERE POTENTIAL STILL APPEARS
TO BE INSTABILITY. STILL EXPECTING RISK TO BE MORE ISOLATED IN
NATURE GIVEN LOWER END INSTABILITY...BUT CANNOT RULE OUT POTENTIAL
OF SOME ISOLATED DAMAGING WIND GUSTS. THREAT SHOULD DIMINISH WITH
EASTWARD EXTENT WITH MORE LIMITED INSTABILITY ACROSS EXTREME
NORTHEAST INDIANA/NORTHWEST OHIO.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM EDT SAT SEP 20 2014

VIGOROUS LEAD SW TROUGH ACRS ERN ND IN ASSOCN W/LARGER SCALE
UPSTREAM DISTURBANCE DROPPING SEWD OUT OF ALBERTA SIGNALS
SIGNIFICANT HGT AMPLIFICATION ALOFT ACRS THE GREAT LAKES THROUGH
SUNDAY. PREFNTL WIND SHIFT IN ASSOCN/W LEAD DISTURBANCE ACTING UPON
A FVRBL RTN FLW LL THETA-E RIDGE TO THE WEST THIS MORNING FM NERN NE
NEWD INTO SERN MN. HWVR XPC THIS ACTIVITY WILL DECAY RATHER ABRUPTLY
EWD THROUGH DAYBREAK AS IT ENCOUNTERS A MUCH MORE STABLE AIRMASS.

PRIMARY SHRT TERM DIFFICULTY IS ACCESSING TEMPORAL EXTENT OF
PROBABLY CONVN LTR THIS AFTN INTO THIS EVE. 12Z GUIDANCE SIMILAR IN
SCOPE W/NARROWING EWD ADVTN OF PLAINS THETA-E PLUME. HIGHRES DETAILS
PER WIND SHIFT TIMING SUGGEST LTL THUNDER THREAT WILL CARRY EWD OF
THE I-69 CORRIDOR AS LL THETA-E RIDGE PINCHES OFF W/NEWD EXTENT AND
HAVE CUT LT AFTN/EVE POP EXTENT ACRS FAR SE FURTHER. OTRWS GIST OF
PREV FCST HOLD YET DID ADD FURTHER TEMPORAL DETAIL BASED ON
CONSENSUS OF PREFERRED HIGHRES GUIDANCE CLUSTERING. CONDITIONAL SVR
THREAT PREDICATED ON ATTAINING SUFFICIENT SFC BASED DESTABILIZATION
LT THIS AFTN W/AREAS WEST OF I-69 CORRIDOR AND SOUTH OF HIGHWAY 30
IN BEST OVERLAP OF 0-6KM SHEAR AND GREATER MODEL IMPLIED HEATING.
REGARDLESS DAMAGING WIND THREAT LOOKS TO REMAIN ISOLD AT BEST.

SFC CDFNT FOLLOWS BUT IN LIGHT OF DIGGING UPSTREAM DISTURBANCE SLWR
TIMING TWD DAYBREAK SUN...IT APPEARS QUITE UNFVRBL FOR ADDNL SHRA OR
TSRA UNTIL LTR SUN AM.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 336 AM EDT SAT SEP 20 2014

SHORTWAVE OF INTEREST WAS WELL DEPICTED ON WATER VAPOR LOOP ENTERING
SASKATCHEWAN AND DROPPING RAPIDLY SE. INCREASING LIFT ASSOCIATED
WITH THIS WAVE WILL BEGIN TO IMPACT THE AREA AS EARLY AS 12Z SUNDAY
WITH PEAK DEVELOPMENT LIKELY OCCURRING IN THE 17 TO 20Z TIME FRAME.
POCKET OF COLD AIR ALOFT (500 MB TEMPS -16 TO -20 C DEPENDING ON
MODEL OF CHOICE) WILL ACCOMPANY THE WAVE WITH TIMING ALSO IN
FAVORABLE EARLY AFTERNOON PERIOD. WHILE MUCH OF THE MOISTURE WILL
HAVE BEEN GUTTED...SFC DEWPOINTS WILL LIKELY STILL BE IN THE LOWER
TO MIDDLE 50S. THIS SHOULD YIELD SOME ELEVATED INSTABILITY WITH
SCATTERED SHOWERS (THUNDER??) LOOKING MORE LIKELY SUN MORNING INTO
MID AFTERNOON BEFORE THE WAVE SHIFTS EAST. HAVE INCREASED POPS
ACROSS NE HALF BUT HELD SHY OF LIKELY FOR NOW.

COLDEST AIR WILL QUICKLY SHIFT AWAY FROM THE REGION BY MONDAY
AFTERNOON WITH MODERATING TEMPERATURES BACK TO NEAR OR EVEN ABOVE
NORMAL AS DEEP TROUGH DIGS INTO THE WESTERN STATES AND REMAINS
PARKED THERE FOR THE FORESEEABLE FUTURE. THIS WILL ALLOW FOR A
LIKELY TRANQUIL WRAP UP TO SEPTEMBER WITH CHANCES FOR MEASURABLE
RAINFALL RATHER BLEAK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 139 PM EDT SAT SEP 20 2014

SCATTERED SHOWERS AND THUNDERSTORMS ARE BEGINNING TO INCREASE IN
COVERAGE EARLY THIS AFTERNOON ACROSS EASTERN IOWA AND NORTHERN
ILLINOIS...JUST DOWNSTREAM OF A WELL PRONOUNCED UPPER LEVEL WAVE
ACROSS EASTERN IOWA. PRIMARY INSTABILITY AXIS SITUATED ACROSS
NORTHERN ILLINOIS SHOULD SHIFT INTO NORTHWEST AND PORTIONS OF
NORTH CENTRAL INDIANA LATE THIS AFTERNOON INTO EARLY THIS EVENING.
SHOULD CONTINUE TO SEE COVERAGE OF SHOWERS AND THUNDERSTORMS
EXPAND ACROSS NORTHEAST ILLINOIS OVER NEXT SEVERAL HOURS...AND
HAVE INTRODUCED TEMPO TSRA MENTION AT KSBN FROM 21Z TO 00Z.
EASTWARD EXTENT OF INSTABILITY MAY BE MORE QUESTIONABLE FOR
THUNDER BUT GIVEN STRENGTH OF UPPER FORCING...PROSPECTS OF THUNDER
AT KFWA APPEAR TO BE INCREASING FOR THIS EVENING. WITH STILL SOME
LOWER CONFIDENCE HOW INSTABILITY FIELDS WILL EVOLVE THIS
AFTERNOON...HAVE LIMITED THUNDER MENTION TO VCTS THIS EVENING AT
KFWA...BUT WILL CERTAINLY NEED TO MONITOR FOR POSSIBLE INCLUSION.
SECONDARY UPPER WAVE ACROSS THE UPPER MIDWEST TO DROP INTO THE
SOUTHERN GREAT LAKES OVERNIGHT KEEPING THE PROSPECTS OF SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS GOING. WIND SHIFT TO THE WEST
EXPECTED EARLY SUNDAY MORNING WITH FRONTAL PASSAGE...WITH WEST
WINDS BECOMING MORE GUSTY IN NATURE TOWARD THE END OF THIS FORECAST
VALID PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043-
     046.

     SMALL CRAFT ADVISORY FROM 10 AM TO 8 PM EDT SUNDAY FOR LMZ043-
     046.

&&

$$

UPDATE...MARSILI
SYNOPSIS...LOTHAMER
SHORT TERM...T
LONG TERM...FISHER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIWX 201607
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1207 PM EDT SAT SEP 20 2014

.SYNOPSIS...
ISSUED AT 339 AM EDT SAT SEP 20 2014

MILD AND BREEZY CONDITIONS WILL DEVELOP TODAY AHEAD OF A COLD
FRONT ADVANCING EASTWARD OUT OF THE PLAINS. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON AND
CONTINUE INTO THIS EVENING. HIGHS THIS AFTERNOON WILL TOP OUT IN
THE UPPER 70S TO LOWER 80S AS SOUTHWEST WINDS GUST UP TO 25 MPH
AT TIMES.

&&

.UPDATE...
ISSUED AT 1154 AM EDT SAT SEP 20 2014

PREVIOUS FORECAST APPEARS TO BE IN GOOD SHAPE WITH CONTINUED FOCUS
ON CONVECTIVE POTENTIAL THIS AFTERNOON. WESTERLY ORIENTED LOW
LEVEL JET WILL CONTINUE TO ADVECT LOW LEVEL THETAE RIDGE EASTWARD
ACROSS NORTHERN INDIANA THIS AFTERNOON. LOW LEVEL DEW POINTS
SHOULD STEADILY INCREASE INTO THE LOWER TO MID 60S THIS AFTERNOON
PARTICULARLY ACROSS WESTERN PORTIONS OF THE FORECAST AREA. THIS
SHOULD LEAD TO AN AXIS OF SURFACE BASED CAPE ON THE ORDER OF
750-1200 J/KG ACROSS WESTERN HALF OF THE AREA THIS AFTERNOON WITH
DEEP LAYER SHEAR INCREASING INTO THE 35 TO 40 KNOT RANGE. WATER
VAPOR IMAGERY IS DEPICTING NEXT SHORT WAVE OF INTEREST ACROSS
EASTERN IOWA AND THIS WILL BE THE FEATURE OF INTEREST TO TRACK
THROUGH EARLY THIS EVENING. AT LEAST A 2 TO 3 HOUR PERIOD OF
INSOLATION IS EXPECTED ACROSS THE AREA THIS AFTERNOON WHICH SHOULD
ALLOW ABOVE INSTABILITY MAGNITUDE TO BE REALIZED. WEAK CIN IS
POSSIBLE THROUGH LATE AFTERNOON BUT WITH EVENTUAL APPROACH OF
UPPER WAVE LATE THIS AFTERNOON ANY WEAK CIN SHOULD BE ERODED
ACROSS THE WEST. WITH FAIRLY STRONG FORCING AND ADEQUATE
SHEAR...MAINLY LIMITING FACTOR TO SEVERE POTENTIAL STILL APPEARS
TO BE INSTABILITY. STILL EXPECTING RISK TO BE MORE ISOLATED IN
NATURE GIVEN LOWER END INSTABILITY...BUT CANNOT RULE OUT POTENTIAL
OF SOME ISOLATED DAMAGING WIND GUSTS. THREAT SHOULD DIMINISH WITH
EASTWARD EXTENT WITH MORE LIMITED INSTABILITY ACROSS EXTREME
NORTHEAST INDIANA/NORTHWEST OHIO.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM EDT SAT SEP 20 2014

VIGOROUS LEAD SW TROUGH ACRS ERN ND IN ASSOCN W/LARGER SCALE
UPSTREAM DISTURBANCE DROPPING SEWD OUT OF ALBERTA SIGNALS
SIGNIFICANT HGT AMPLIFICATION ALOFT ACRS THE GREAT LAKES THROUGH
SUNDAY. PREFNTL WIND SHIFT IN ASSOCN/W LEAD DISTURBANCE ACTING UPON
A FVRBL RTN FLW LL THETA-E RIDGE TO THE WEST THIS MORNING FM NERN NE
NEWD INTO SERN MN. HWVR XPC THIS ACTIVITY WILL DECAY RATHER ABRUPTLY
EWD THROUGH DAYBREAK AS IT ENCOUNTERS A MUCH MORE STABLE AIRMASS.

PRIMARY SHRT TERM DIFFICULTY IS ACCESSING TEMPORAL EXTENT OF
PROBABLY CONVN LTR THIS AFTN INTO THIS EVE. 12Z GUIDANCE SIMILAR IN
SCOPE W/NARROWING EWD ADVTN OF PLAINS THETA-E PLUME. HIGHRES DETAILS
PER WIND SHIFT TIMING SUGGEST LTL THUNDER THREAT WILL CARRY EWD OF
THE I-69 CORRIDOR AS LL THETA-E RIDGE PINCHES OFF W/NEWD EXTENT AND
HAVE CUT LT AFTN/EVE POP EXTENT ACRS FAR SE FURTHER. OTRWS GIST OF
PREV FCST HOLD YET DID ADD FURTHER TEMPORAL DETAIL BASED ON
CONSENSUS OF PREFERRED HIGHRES GUIDANCE CLUSTERING. CONDITIONAL SVR
THREAT PREDICATED ON ATTAINING SUFFICIENT SFC BASED DESTABILIZATION
LT THIS AFTN W/AREAS WEST OF I-69 CORRIDOR AND SOUTH OF HIGHWAY 30
IN BEST OVERLAP OF 0-6KM SHEAR AND GREATER MODEL IMPLIED HEATING.
REGARDLESS DAMAGING WIND THREAT LOOKS TO REMAIN ISOLD AT BEST.

SFC CDFNT FOLLOWS BUT IN LIGHT OF DIGGING UPSTREAM DISTURBANCE SLWR
TIMING TWD DAYBREAK SUN...IT APPEARS QUITE UNFVRBL FOR ADDNL SHRA OR
TSRA UNTIL LTR SUN AM.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 336 AM EDT SAT SEP 20 2014

SHORTWAVE OF INTEREST WAS WELL DEPICTED ON WATER VAPOR LOOP ENTERING
SASKATCHEWAN AND DROPPING RAPIDLY SE. INCREASING LIFT ASSOCIATED
WITH THIS WAVE WILL BEGIN TO IMPACT THE AREA AS EARLY AS 12Z SUNDAY
WITH PEAK DEVELOPMENT LIKELY OCCURRING IN THE 17 TO 20Z TIME FRAME.
POCKET OF COLD AIR ALOFT (500 MB TEMPS -16 TO -20 C DEPENDING ON
MODEL OF CHOICE) WILL ACCOMPANY THE WAVE WITH TIMING ALSO IN
FAVORABLE EARLY AFTERNOON PERIOD. WHILE MUCH OF THE MOISTURE WILL
HAVE BEEN GUTTED...SFC DEWPOINTS WILL LIKELY STILL BE IN THE LOWER
TO MIDDLE 50S. THIS SHOULD YIELD SOME ELEVATED INSTABILITY WITH
SCATTERED SHOWERS (THUNDER??) LOOKING MORE LIKELY SUN MORNING INTO
MID AFTERNOON BEFORE THE WAVE SHIFTS EAST. HAVE INCREASED POPS
ACROSS NE HALF BUT HELD SHY OF LIKELY FOR NOW.

COLDEST AIR WILL QUICKLY SHIFT AWAY FROM THE REGION BY MONDAY
AFTERNOON WITH MODERATING TEMPERATURES BACK TO NEAR OR EVEN ABOVE
NORMAL AS DEEP TROUGH DIGS INTO THE WESTERN STATES AND REMAINS
PARKED THERE FOR THE FORESEEABLE FUTURE. THIS WILL ALLOW FOR A
LIKELY TRANQUIL WRAP UP TO SEPTEMBER WITH CHANCES FOR MEASURABLE
RAINFALL RATHER BLEAK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 339 AM EDT SAT SEP 20 2014

VFR CONDS XPCD THROUGH THE PD. RAPID DECAY OF UPSTREAM CONVN XPCD
THROUGH DAYBREAK W/CONCURRENT BURGEONING MIXED LYR XPCD BY MID
MORNING. SFC GUSTS AOA 20KTS XPCD THROUGH MID AFTN AHD OF PREFNTL
WIND SHIFT. OTRWS CONV INITIATION NW OF KSBN TERMINAL XPCD IN 19-20Z
TIME FRAME FOLLOWED BY E/SE PROGRESSION OF GENERALLY WKNG LINE. WILL
HOLD W/PRIOR FCST VCTS MENTION FOR THIS AFTN/EVE AND REACCESS
PINPOINTING GREATER TEMPORAL DETAILS W/12Z ISSUANCE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043-
     046.

     SMALL CRAFT ADVISORY FROM 10 AM TO 8 PM EDT SUNDAY FOR LMZ043-
     046.

&&

$$

UPDATE...MARSILI
SYNOPSIS...LOTHAMER
SHORT TERM...T
LONG TERM...FISHER
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

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000
FXUS63 KIWX 201607
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1207 PM EDT SAT SEP 20 2014

.SYNOPSIS...
ISSUED AT 339 AM EDT SAT SEP 20 2014

MILD AND BREEZY CONDITIONS WILL DEVELOP TODAY AHEAD OF A COLD
FRONT ADVANCING EASTWARD OUT OF THE PLAINS. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON AND
CONTINUE INTO THIS EVENING. HIGHS THIS AFTERNOON WILL TOP OUT IN
THE UPPER 70S TO LOWER 80S AS SOUTHWEST WINDS GUST UP TO 25 MPH
AT TIMES.

&&

.UPDATE...
ISSUED AT 1154 AM EDT SAT SEP 20 2014

PREVIOUS FORECAST APPEARS TO BE IN GOOD SHAPE WITH CONTINUED FOCUS
ON CONVECTIVE POTENTIAL THIS AFTERNOON. WESTERLY ORIENTED LOW
LEVEL JET WILL CONTINUE TO ADVECT LOW LEVEL THETAE RIDGE EASTWARD
ACROSS NORTHERN INDIANA THIS AFTERNOON. LOW LEVEL DEW POINTS
SHOULD STEADILY INCREASE INTO THE LOWER TO MID 60S THIS AFTERNOON
PARTICULARLY ACROSS WESTERN PORTIONS OF THE FORECAST AREA. THIS
SHOULD LEAD TO AN AXIS OF SURFACE BASED CAPE ON THE ORDER OF
750-1200 J/KG ACROSS WESTERN HALF OF THE AREA THIS AFTERNOON WITH
DEEP LAYER SHEAR INCREASING INTO THE 35 TO 40 KNOT RANGE. WATER
VAPOR IMAGERY IS DEPICTING NEXT SHORT WAVE OF INTEREST ACROSS
EASTERN IOWA AND THIS WILL BE THE FEATURE OF INTEREST TO TRACK
THROUGH EARLY THIS EVENING. AT LEAST A 2 TO 3 HOUR PERIOD OF
INSOLATION IS EXPECTED ACROSS THE AREA THIS AFTERNOON WHICH SHOULD
ALLOW ABOVE INSTABILITY MAGNITUDE TO BE REALIZED. WEAK CIN IS
POSSIBLE THROUGH LATE AFTERNOON BUT WITH EVENTUAL APPROACH OF
UPPER WAVE LATE THIS AFTERNOON ANY WEAK CIN SHOULD BE ERODED
ACROSS THE WEST. WITH FAIRLY STRONG FORCING AND ADEQUATE
SHEAR...MAINLY LIMITING FACTOR TO SEVERE POTENTIAL STILL APPEARS
TO BE INSTABILITY. STILL EXPECTING RISK TO BE MORE ISOLATED IN
NATURE GIVEN LOWER END INSTABILITY...BUT CANNOT RULE OUT POTENTIAL
OF SOME ISOLATED DAMAGING WIND GUSTS. THREAT SHOULD DIMINISH WITH
EASTWARD EXTENT WITH MORE LIMITED INSTABILITY ACROSS EXTREME
NORTHEAST INDIANA/NORTHWEST OHIO.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM EDT SAT SEP 20 2014

VIGOROUS LEAD SW TROUGH ACRS ERN ND IN ASSOCN W/LARGER SCALE
UPSTREAM DISTURBANCE DROPPING SEWD OUT OF ALBERTA SIGNALS
SIGNIFICANT HGT AMPLIFICATION ALOFT ACRS THE GREAT LAKES THROUGH
SUNDAY. PREFNTL WIND SHIFT IN ASSOCN/W LEAD DISTURBANCE ACTING UPON
A FVRBL RTN FLW LL THETA-E RIDGE TO THE WEST THIS MORNING FM NERN NE
NEWD INTO SERN MN. HWVR XPC THIS ACTIVITY WILL DECAY RATHER ABRUPTLY
EWD THROUGH DAYBREAK AS IT ENCOUNTERS A MUCH MORE STABLE AIRMASS.

PRIMARY SHRT TERM DIFFICULTY IS ACCESSING TEMPORAL EXTENT OF
PROBABLY CONVN LTR THIS AFTN INTO THIS EVE. 12Z GUIDANCE SIMILAR IN
SCOPE W/NARROWING EWD ADVTN OF PLAINS THETA-E PLUME. HIGHRES DETAILS
PER WIND SHIFT TIMING SUGGEST LTL THUNDER THREAT WILL CARRY EWD OF
THE I-69 CORRIDOR AS LL THETA-E RIDGE PINCHES OFF W/NEWD EXTENT AND
HAVE CUT LT AFTN/EVE POP EXTENT ACRS FAR SE FURTHER. OTRWS GIST OF
PREV FCST HOLD YET DID ADD FURTHER TEMPORAL DETAIL BASED ON
CONSENSUS OF PREFERRED HIGHRES GUIDANCE CLUSTERING. CONDITIONAL SVR
THREAT PREDICATED ON ATTAINING SUFFICIENT SFC BASED DESTABILIZATION
LT THIS AFTN W/AREAS WEST OF I-69 CORRIDOR AND SOUTH OF HIGHWAY 30
IN BEST OVERLAP OF 0-6KM SHEAR AND GREATER MODEL IMPLIED HEATING.
REGARDLESS DAMAGING WIND THREAT LOOKS TO REMAIN ISOLD AT BEST.

SFC CDFNT FOLLOWS BUT IN LIGHT OF DIGGING UPSTREAM DISTURBANCE SLWR
TIMING TWD DAYBREAK SUN...IT APPEARS QUITE UNFVRBL FOR ADDNL SHRA OR
TSRA UNTIL LTR SUN AM.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 336 AM EDT SAT SEP 20 2014

SHORTWAVE OF INTEREST WAS WELL DEPICTED ON WATER VAPOR LOOP ENTERING
SASKATCHEWAN AND DROPPING RAPIDLY SE. INCREASING LIFT ASSOCIATED
WITH THIS WAVE WILL BEGIN TO IMPACT THE AREA AS EARLY AS 12Z SUNDAY
WITH PEAK DEVELOPMENT LIKELY OCCURRING IN THE 17 TO 20Z TIME FRAME.
POCKET OF COLD AIR ALOFT (500 MB TEMPS -16 TO -20 C DEPENDING ON
MODEL OF CHOICE) WILL ACCOMPANY THE WAVE WITH TIMING ALSO IN
FAVORABLE EARLY AFTERNOON PERIOD. WHILE MUCH OF THE MOISTURE WILL
HAVE BEEN GUTTED...SFC DEWPOINTS WILL LIKELY STILL BE IN THE LOWER
TO MIDDLE 50S. THIS SHOULD YIELD SOME ELEVATED INSTABILITY WITH
SCATTERED SHOWERS (THUNDER??) LOOKING MORE LIKELY SUN MORNING INTO
MID AFTERNOON BEFORE THE WAVE SHIFTS EAST. HAVE INCREASED POPS
ACROSS NE HALF BUT HELD SHY OF LIKELY FOR NOW.

COLDEST AIR WILL QUICKLY SHIFT AWAY FROM THE REGION BY MONDAY
AFTERNOON WITH MODERATING TEMPERATURES BACK TO NEAR OR EVEN ABOVE
NORMAL AS DEEP TROUGH DIGS INTO THE WESTERN STATES AND REMAINS
PARKED THERE FOR THE FORESEEABLE FUTURE. THIS WILL ALLOW FOR A
LIKELY TRANQUIL WRAP UP TO SEPTEMBER WITH CHANCES FOR MEASURABLE
RAINFALL RATHER BLEAK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 339 AM EDT SAT SEP 20 2014

VFR CONDS XPCD THROUGH THE PD. RAPID DECAY OF UPSTREAM CONVN XPCD
THROUGH DAYBREAK W/CONCURRENT BURGEONING MIXED LYR XPCD BY MID
MORNING. SFC GUSTS AOA 20KTS XPCD THROUGH MID AFTN AHD OF PREFNTL
WIND SHIFT. OTRWS CONV INITIATION NW OF KSBN TERMINAL XPCD IN 19-20Z
TIME FRAME FOLLOWED BY E/SE PROGRESSION OF GENERALLY WKNG LINE. WILL
HOLD W/PRIOR FCST VCTS MENTION FOR THIS AFTN/EVE AND REACCESS
PINPOINTING GREATER TEMPORAL DETAILS W/12Z ISSUANCE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043-
     046.

     SMALL CRAFT ADVISORY FROM 10 AM TO 8 PM EDT SUNDAY FOR LMZ043-
     046.

&&

$$

UPDATE...MARSILI
SYNOPSIS...LOTHAMER
SHORT TERM...T
LONG TERM...FISHER
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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000
FXUS63 KIWX 200740
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
340 AM EDT SAT SEP 20 2014

.SYNOPSIS...
ISSUED AT 339 AM EDT SAT SEP 20 2014

MILD AND BREEZY CONDITIONS WILL DEVELOP TODAY AHEAD OF A COLD
FRONT ADVANCING EASTWARD OUT OF THE PLAINS. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON AND
CONTINUE INTO THIS EVENING. HIGHS THIS AFTERNOON WILL TOP OUT IN
THE UPPER 70S TO LOWER 80S AS SOUTHWEST WINDS GUST UP TO 25 MPH
AT TIMES.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM EDT SAT SEP 20 2014

VIGOROUS LEAD SW TROUGH ACRS ERN ND IN ASSOCN W/LARGER SCALE
UPSTREAM DISTURBANCE DROPPING SEWD OUT OF ALBERTA SIGNALS
SIGNIFICANT HGT AMPLIFICATION ALOFT ACRS THE GREAT LAKES THROUGH
SUNDAY. PREFNTL WIND SHIFT IN ASSOCN/W LEAD DISTURBANCE ACTING UPON
A FVRBL RTN FLW LL THETA-E RIDGE TO THE WEST THIS MORNING FM NERN NE
NEWD INTO SERN MN. HWVR XPC THIS ACTIVITY WILL DECAY RATHER ABRUPTLY
EWD THROUGH DAYBREAK AS IT ENCOUNTERS A MUCH MORE STABLE AIRMASS.

PRIMARY SHRT TERM DIFFICULTY IS ACCESSING TEMPORAL EXTENT OF
PROBABLY CONVN LTR THIS AFTN INTO THIS EVE. 12Z GUIDANCE SIMILAR IN
SCOPE W/NARROWING EWD ADVTN OF PLAINS THETA-E PLUME. HIGHRES DETAILS
PER WIND SHIFT TIMING SUGGEST LTL THUNDER THREAT WILL CARRY EWD OF
THE I-69 CORRIDOR AS LL THETA-E RIDGE PINCHES OFF W/NEWD EXTENT AND
HAVE CUT LT AFTN/EVE POP EXTENT ACRS FAR SE FURTHER. OTRWS GIST OF
PREV FCST HOLD YET DID ADD FURTHER TEMPORAL DETAIL BASED ON
CONSENSUS OF PREFERRED HIGHRES GUIDANCE CLUSTERING. CONDITIONAL SVR
THREAT PREDICATED ON ATTAINING SUFFICIENT SFC BASED DESTABILIZATION
LT THIS AFTN W/AREAS WEST OF I-69 CORRIDOR AND SOUTH OF HIGHWAY 30
IN BEST OVERLAP OF 0-6KM SHEAR AND GREATER MODEL IMPLIED HEATING.
REGARDLESS DAMAGING WIND THREAT LOOKS TO REMAIN ISOLD AT BEST.

SFC CDFNT FOLLOWS BUT IN LIGHT OF DIGGING UPSTREAM DISTURBANCE SLWR
TIMING TWD DAYBREAK SUN...IT APPEARS QUITE UNFVRBL FOR ADDNL SHRA OR
TSRA UNTIL LTR SUN AM.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 336 AM EDT SAT SEP 20 2014

SHORTWAVE OF INTEREST WAS WELL DEPICTED ON WATER VAPOR LOOP ENTERING
SASKATCHEWAN AND DROPPING RAPIDLY SE. INCREASING LIFT ASSOCIATED
WITH THIS WAVE WILL BEGIN TO IMPACT THE AREA AS EARLY AS 12Z SUNDAY
WITH PEAK DEVELOPMENT LIKELY OCCURRING IN THE 17 TO 20Z TIME FRAME.
POCKET OF COLD AIR ALOFT (500 MB TEMPS -16 TO -20 C DEPENDING ON
MODEL OF CHOICE) WILL ACCOMPANY THE WAVE WITH TIMING ALSO IN
FAVORABLE EARLY AFTERNOON PERIOD. WHILE MUCH OF THE MOISTURE WILL
HAVE BEEN GUTTED...SFC DEWPOINTS WILL LIKELY STILL BE IN THE LOWER
TO MIDDLE 50S. THIS SHOULD YIELD SOME ELEVATED INSTABILITY WITH
SCATTERED SHOWERS (THUNDER??) LOOKING MORE LIKELY SUN MORNING INTO
MID AFTERNOON BEFORE THE WAVE SHIFTS EAST. HAVE INCREASED POPS
ACROSS NE HALF BUT HELD SHY OF LIKELY FOR NOW.

COLDEST AIR WILL QUICKLY SHIFT AWAY FROM THE REGION BY MONDAY
AFTERNOON WITH MODERATING TEMPERATURES BACK TO NEAR OR EVEN ABOVE
NORMAL AS DEEP TROUGH DIGS INTO THE WESTERN STATES AND REMAINS
PARKED THERE FOR THE FORESEEABLE FUTURE. THIS WILL ALLOW FOR A
LIKELY TRANQUIL WRAP UP TO SEPTEMBER WITH CHANCES FOR MEASURABLE
RAINFALL RATHER BLEAK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 339 AM EDT SAT SEP 20 2014

VFR CONDS XPCD THROUGH THE PD. RAPID DECAY OF UPSTREAM CONVN XPCD
THROUGH DAYBREAK W/CONCURRENT BURGEONING MIXED LYR XPCD BY MID
MORNING. SFC GUSTS AOA 20KTS XPCD THROUGH MID AFTN AHD OF PREFNTL
WIND SHIFT. OTRWS CONV INITIATION NW OF KSBN TERMINAL XPCD IN 19-20Z
TIME FRAME FOLLOWED BY E/SE PROGRESSION OF GENERALLY WKNG LINE. WILL
HOLD W/PRIOR FCST VCTS MENTION FOR THIS AFTN/EVE AND REACCESS
PINPOINTING GREATER TEMPORAL DETAILS W/12Z ISSUANCE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...LOTHAMER
SHORT TERM...T
LONG TERM...FISHER
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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000
FXUS63 KIWX 200013
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
813 PM EDT FRI SEP 19 2014

.SYNOPSIS...
ISSUED AT 758 PM EDT FRI SEP 19 2014

HIGH PRESSURE CURRENTLY OVER THE AREA WILL CONTINUE TO MOVE
EASTWARD THROUGH TONIGHT AND THEN EXPECT AN UPPER LEVEL
DISTURBANCE TO MOVE THROUGH SATURDAY. SCATTERED SHOWERS AND
THUNDERSTORMS MAY MOVE INTO THE SOUTHERN GREAT LAKES BY
MORNING...BUT THE COVERAGE OF SHOWERS AND THUNDERSTORMS IS
EXPECTED TO INCREASE LATER IN THE AFTERNOON AND EVENING. LOW
TEMPERATURES TONIGHT WILL BE IN THE LOWER TO MIDDLE 50S. HIGH
TEMPERATURES TOMORROW WILL BE IN THE UPPER 70S TO LOWER 80S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

CONVECTIVE POTENTIAL ON SATURDAY/SATURDAY NIGHT WILL CONTINUE TO
BE THE PRIMARY FOCUS OF THE SHORT TERM.

IN THE MEANTIME...BROAD LOW AMPLITUDE UPPER LEVEL RIDGING WILL
QUICKLY TRANSLATE EASTWARD ACROSS THE GREAT LAKES/OHIO VALLEY
THIS MORNING WITH CONTINUED SLOW EASTWARD MIGRATION OF LOW LEVEL
ANTICYCLONE NORTHEAST CONUS/SOUTHEAST CANADA. A 50-60 KNOT LLJ IS
EXPECTED TO TAKE SHAPE TONIGHT...WITH STRONGEST LOW LEVEL MOIST
TRANSPORT TAKING SHAPE FROM MID MS RIVER VALLEY NORTHEASTWARD
INTO THE WESTERN GREAT LAKES REGION LATER TONIGHT. CONVECTION MAY
DEVELOP IN ASSOCIATION WITH STRENGTHENING LLJ AND WEAK UPPER
PERTURBATIONS ENTERING WESTERN GREAT LAKES OVERNIGHT. HAVE KEPT
FORECAST AREA DRY OVERNIGHT...ALTHOUGH A VERY LOW END CHANCE OF A
SHOWER MAY EXIST ACROSS THE FAR NORTHWEST TOWARD DAYBREAK AS
STRONGER LOW/MID LEVEL THETAE ADVECTION PROGRESSES INTO THE AREA.
OTHERWISE FOR TONIGHT...MID AND HIGH LEVEL CLOUDS WILL BE ON THE
INCREASE PARTICULARLY DURING THE OVERNIGHT HOURS WHICH COMBINED
WITH STRENGTHENING LOW LEVEL WAA WILL PROVIDE MILDER MINS FROM
THE MID TO UPPER 50S...TO THE LOWER 50S OR AROUND 50 EAST.

STILL PLENTY OF UNCERTAINTY REMAINING IN REGARDS TO
CONVECTIVE/SEVERE RISK FOR SATURDAY. CONVECTION MAY BE ONGOING
EARLY SATURDAY MORNING ACROSS THE WESTERN GREAT LAKES IN
ASSOCIATION WITH AFOREMENTIONED LLJ FORCING. WHILE PROPAGATION
VECTORS WOULD TEND TO KEEP THIS ACTIVITY NORTH OF LOCAL
AREA...SOME ADDITIONAL DEVELOPMENT ALONG RESIDUAL OUTFLOW
BOUNDARIES COULD ALLOW FOR A FEW SHOWERS/ISOLATED STORMS TO WORK
INTO FAR NORTHWEST PORTIONS OF THE AREA AFTER DAYBREAK...BUT
CONFIDENCE IN THIS SCENARIO IS LOW. NEXT UPSTREAM MID LEVEL
TROUGH WILL APPROACH THE GREAT LAKES LATE SATURDAY MORNING
ALLOWING FOR AXIS OF STRONG LOW LEVEL MOISTURE CONVERGENCE TO
SHIFT ACROSS APPROXIMATELY NORTHERN HALF OF THE AREA. AS PREVIOUS
DISCUSSION MENTIONED...AVAILABLE INSTABILITY DURING THE DAY
SATURDAY WILL BE HIGHLY SENSITIVE TO NEAR SFC/SFC
TEMPERATURES...AND GIVEN THE ABOVE INCREASE IN FORCING...SOME
POSSIBILITY EXISTS FOR THIS INSTABILITY TO BE TEMPERED. WHILE
MOISTURE TRANSPORT WILL BE STRONG PRECEDING THE FRONT...NAM MAY
BE A BIT AGGRESSIVE WITH SFC DEW POINTS...AND THUS A BIT ON THE
AGGRESSIVE SIDE WITH INSTABILITY PROGS. NEVERTHELESS..GIVEN
STEEPISH MID LEVEL LAPSE RATES...SURFACE BASED CAPES ON THE ORDER
OF 750-1500 J/KG AT LEAST APPEAR TO BE A POSSIBILITY DEPENDING ON
EXTENT OF CLOUD COVER. DEEP LAYER SHEAR AND 0-3 KM SHEAR VECTORS
SHOULD STEADILY STRENGTHEN DURING THE DAY AS BELT OF STRONGER
MID/UPPER LEVEL WESTERLIES PROGRESSES THROUGH BASE OF THE MID
LEVEL TROUGH. GIVEN LOW/MODERATE INSTABILITY AND HIGH SHEAR
ENVIRONMENT...CANNOT RULE OUT AT LEAST AN ISOLD SEVERE THREAT
(MAINLY ISOLD DAMAGING WIND GUSTS) DEPENDING ON HOW INSTABILITY
EVOLVES GIVEN STRENGTHENING BACKGROUND WIND FIELD AND
UNIDIRECTIONAL NATURE TO FLOW. WINDOW OF SEVERE POTENTIAL SHOULD
BE SOMEWHAT LIMITED...WITH PRELIMINARY INDICATIONS IN THE 21Z-03Z
TIMEFRAME.

A PUNCH OF DRIER MID LEVEL AIR TO ADVECT INTO THE AREA
OVERNIGHT...BUT SECONDARY AXIS OF PREFRONTAL LOW LEVEL MOISTURE
POOLING SHOULD KEEP ENOUGH ELEVATED INSTABILITY IN PLACE FOR
CONTINUED SCATTERED SHOWER/THUNDERSTORMS DURING THE OVERNIGHT
HOURS AS NEXT UPSTREAM UPPER LEVEL TROUGH APPROACHES. SLIGHTLY
MORE DELAYED FROPA EARLY SUNDAY MORNING AND ABUNDANT CLOUD COVER
WILL PROVIDE MILDER MINS IN THE LOWER AND MID 60S.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

LONG TERM PERIOD BEGINS SUNDAY MORNING WITH DRY SLOT BEHIND COLD
FRONT INITIALLY OVER THE AREA. MOST PCPN ASSOCIATED WITH FRONTAL
BOUNDARY SHOULD BE EXITING THE AREA BY 12Z. MODEL SOUNDINGS
INDICATE POST FRONTAL INVERSION WITH TRAPPED LOW LEVEL MOISTURE
SUGGESTING LINGERING CLOUD COVER INTO EARLY AFTERNOON. WE HAVE
BEEN DISCUSSING THE POSSIBILITY OF SHOWERS WITH SECONDARY SHORT
WAVE FOR SEVERAL DAYS. LATEST MODEL GUIDANCE SHOWING A RATHER
STRONG PV ANOMALY NOW DROPPING INTO THE AREA BY MID DAY WITH
STRONG DPVA WITHIN THIS SHORT WAVE TROUGH. DEEPER MOISTURE IS
CERTAINLY SCOURED AS THIS FEATURE NEARS BUT CONCERN LIES WITH
TRAPPED LOW LEVEL MOISTURE AND ANY WEAK LAKE CONTRIBUTION
PROVIDING ENOUGH MOISTURE WITH LARGE SCALE LIFT TO PRODUCE SOME
LIGHT SHOWERS. SOUNDINGS ALSO INDICATE A BIT OF ELEVATED
INSTABILITY IN WAKE OF MAIN COLD FRONT. HAVE THEREFORE ADDED SOME
LOW CHANCE POPS BACK TO FORECAST SUNDAY...ESPECIALLY NORTH AND
EAST WHERE STRONGER INFLUENCE OF PV ANOMALY SEEMS TO BE FOCUSED
WITH AGREEMENT AMONG THE MODELS. PASSAGE OF THIS FEATURE SHOULD
THEN LEAD TO CLEARING SKIES AND COOLER TEMPERATURES SUNDAY NIGHT.

MODELS HAVE CONTINUED TO TREND WARMER POST FRONTAL WITH MODIFIED
AIRMASS AND DEEPER TROUGH AXIS TO OUR EAST MONDAY. SURFACE HIGH
PRESSURE WILL SETTLE IN MONDAY AND CONTINUE THROUGH THE END OF
THE WEEK WITH A MODERATING TEMPERATURE TREND. EXPECT TEMPS
SIMILAR TO LAST FEW DAYS WITH LOWS IN THE LOWER 40S AND HIGHS IN
THE 60S TO BEGIN THE WEEK BUT WARMING TO LOWS IN THE 50S AND
HIGHS IN THE 70S BY MID TO LATE WEEK. DRY CONDITIONS TO EXIST
WITH RIDGING ALOFT BECOMING ANCHORED RIGHT OVER THE AREA THROUGH
THE WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 809 PM EDT FRI SEP 19 2014

VFR MET CONDITIONS TO DOMINATE THROUGH THE FORECAST PERIOD.
SHARPENING UPSTREAM TROF TO BRING INCREASE IN DEEP LAYER SHEAR TO
REGION SAT AFTERNOON. CONCERN CONTINUES TO REVOLVE AROUND DEGREE
OF INSTABILITY AS ANTICIPATED EARLY MORNING DECAY OF UPSTREAM
CONVECTION MAY INHIBIT SFC HEATING. FOR NOW WILL INTRODUCE AS
VCTS LATE IN FORECAST PERIOD AT KSBN WITH KFWA CONCVECTION FREE
DUE TO BOTH LATER TIMING AND PREVALENT HEIGHT FALL CENTROID TRACK
REMAINING WELL NORTH /NERN WI MIDDAY INTO LAKE HURON SAT
EVENING/.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
     SATURDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...LOTHAMER
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

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000
FXUS63 KIWX 200013
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
813 PM EDT FRI SEP 19 2014

.SYNOPSIS...
ISSUED AT 758 PM EDT FRI SEP 19 2014

HIGH PRESSURE CURRENTLY OVER THE AREA WILL CONTINUE TO MOVE
EASTWARD THROUGH TONIGHT AND THEN EXPECT AN UPPER LEVEL
DISTURBANCE TO MOVE THROUGH SATURDAY. SCATTERED SHOWERS AND
THUNDERSTORMS MAY MOVE INTO THE SOUTHERN GREAT LAKES BY
MORNING...BUT THE COVERAGE OF SHOWERS AND THUNDERSTORMS IS
EXPECTED TO INCREASE LATER IN THE AFTERNOON AND EVENING. LOW
TEMPERATURES TONIGHT WILL BE IN THE LOWER TO MIDDLE 50S. HIGH
TEMPERATURES TOMORROW WILL BE IN THE UPPER 70S TO LOWER 80S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

CONVECTIVE POTENTIAL ON SATURDAY/SATURDAY NIGHT WILL CONTINUE TO
BE THE PRIMARY FOCUS OF THE SHORT TERM.

IN THE MEANTIME...BROAD LOW AMPLITUDE UPPER LEVEL RIDGING WILL
QUICKLY TRANSLATE EASTWARD ACROSS THE GREAT LAKES/OHIO VALLEY
THIS MORNING WITH CONTINUED SLOW EASTWARD MIGRATION OF LOW LEVEL
ANTICYCLONE NORTHEAST CONUS/SOUTHEAST CANADA. A 50-60 KNOT LLJ IS
EXPECTED TO TAKE SHAPE TONIGHT...WITH STRONGEST LOW LEVEL MOIST
TRANSPORT TAKING SHAPE FROM MID MS RIVER VALLEY NORTHEASTWARD
INTO THE WESTERN GREAT LAKES REGION LATER TONIGHT. CONVECTION MAY
DEVELOP IN ASSOCIATION WITH STRENGTHENING LLJ AND WEAK UPPER
PERTURBATIONS ENTERING WESTERN GREAT LAKES OVERNIGHT. HAVE KEPT
FORECAST AREA DRY OVERNIGHT...ALTHOUGH A VERY LOW END CHANCE OF A
SHOWER MAY EXIST ACROSS THE FAR NORTHWEST TOWARD DAYBREAK AS
STRONGER LOW/MID LEVEL THETAE ADVECTION PROGRESSES INTO THE AREA.
OTHERWISE FOR TONIGHT...MID AND HIGH LEVEL CLOUDS WILL BE ON THE
INCREASE PARTICULARLY DURING THE OVERNIGHT HOURS WHICH COMBINED
WITH STRENGTHENING LOW LEVEL WAA WILL PROVIDE MILDER MINS FROM
THE MID TO UPPER 50S...TO THE LOWER 50S OR AROUND 50 EAST.

STILL PLENTY OF UNCERTAINTY REMAINING IN REGARDS TO
CONVECTIVE/SEVERE RISK FOR SATURDAY. CONVECTION MAY BE ONGOING
EARLY SATURDAY MORNING ACROSS THE WESTERN GREAT LAKES IN
ASSOCIATION WITH AFOREMENTIONED LLJ FORCING. WHILE PROPAGATION
VECTORS WOULD TEND TO KEEP THIS ACTIVITY NORTH OF LOCAL
AREA...SOME ADDITIONAL DEVELOPMENT ALONG RESIDUAL OUTFLOW
BOUNDARIES COULD ALLOW FOR A FEW SHOWERS/ISOLATED STORMS TO WORK
INTO FAR NORTHWEST PORTIONS OF THE AREA AFTER DAYBREAK...BUT
CONFIDENCE IN THIS SCENARIO IS LOW. NEXT UPSTREAM MID LEVEL
TROUGH WILL APPROACH THE GREAT LAKES LATE SATURDAY MORNING
ALLOWING FOR AXIS OF STRONG LOW LEVEL MOISTURE CONVERGENCE TO
SHIFT ACROSS APPROXIMATELY NORTHERN HALF OF THE AREA. AS PREVIOUS
DISCUSSION MENTIONED...AVAILABLE INSTABILITY DURING THE DAY
SATURDAY WILL BE HIGHLY SENSITIVE TO NEAR SFC/SFC
TEMPERATURES...AND GIVEN THE ABOVE INCREASE IN FORCING...SOME
POSSIBILITY EXISTS FOR THIS INSTABILITY TO BE TEMPERED. WHILE
MOISTURE TRANSPORT WILL BE STRONG PRECEDING THE FRONT...NAM MAY
BE A BIT AGGRESSIVE WITH SFC DEW POINTS...AND THUS A BIT ON THE
AGGRESSIVE SIDE WITH INSTABILITY PROGS. NEVERTHELESS..GIVEN
STEEPISH MID LEVEL LAPSE RATES...SURFACE BASED CAPES ON THE ORDER
OF 750-1500 J/KG AT LEAST APPEAR TO BE A POSSIBILITY DEPENDING ON
EXTENT OF CLOUD COVER. DEEP LAYER SHEAR AND 0-3 KM SHEAR VECTORS
SHOULD STEADILY STRENGTHEN DURING THE DAY AS BELT OF STRONGER
MID/UPPER LEVEL WESTERLIES PROGRESSES THROUGH BASE OF THE MID
LEVEL TROUGH. GIVEN LOW/MODERATE INSTABILITY AND HIGH SHEAR
ENVIRONMENT...CANNOT RULE OUT AT LEAST AN ISOLD SEVERE THREAT
(MAINLY ISOLD DAMAGING WIND GUSTS) DEPENDING ON HOW INSTABILITY
EVOLVES GIVEN STRENGTHENING BACKGROUND WIND FIELD AND
UNIDIRECTIONAL NATURE TO FLOW. WINDOW OF SEVERE POTENTIAL SHOULD
BE SOMEWHAT LIMITED...WITH PRELIMINARY INDICATIONS IN THE 21Z-03Z
TIMEFRAME.

A PUNCH OF DRIER MID LEVEL AIR TO ADVECT INTO THE AREA
OVERNIGHT...BUT SECONDARY AXIS OF PREFRONTAL LOW LEVEL MOISTURE
POOLING SHOULD KEEP ENOUGH ELEVATED INSTABILITY IN PLACE FOR
CONTINUED SCATTERED SHOWER/THUNDERSTORMS DURING THE OVERNIGHT
HOURS AS NEXT UPSTREAM UPPER LEVEL TROUGH APPROACHES. SLIGHTLY
MORE DELAYED FROPA EARLY SUNDAY MORNING AND ABUNDANT CLOUD COVER
WILL PROVIDE MILDER MINS IN THE LOWER AND MID 60S.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

LONG TERM PERIOD BEGINS SUNDAY MORNING WITH DRY SLOT BEHIND COLD
FRONT INITIALLY OVER THE AREA. MOST PCPN ASSOCIATED WITH FRONTAL
BOUNDARY SHOULD BE EXITING THE AREA BY 12Z. MODEL SOUNDINGS
INDICATE POST FRONTAL INVERSION WITH TRAPPED LOW LEVEL MOISTURE
SUGGESTING LINGERING CLOUD COVER INTO EARLY AFTERNOON. WE HAVE
BEEN DISCUSSING THE POSSIBILITY OF SHOWERS WITH SECONDARY SHORT
WAVE FOR SEVERAL DAYS. LATEST MODEL GUIDANCE SHOWING A RATHER
STRONG PV ANOMALY NOW DROPPING INTO THE AREA BY MID DAY WITH
STRONG DPVA WITHIN THIS SHORT WAVE TROUGH. DEEPER MOISTURE IS
CERTAINLY SCOURED AS THIS FEATURE NEARS BUT CONCERN LIES WITH
TRAPPED LOW LEVEL MOISTURE AND ANY WEAK LAKE CONTRIBUTION
PROVIDING ENOUGH MOISTURE WITH LARGE SCALE LIFT TO PRODUCE SOME
LIGHT SHOWERS. SOUNDINGS ALSO INDICATE A BIT OF ELEVATED
INSTABILITY IN WAKE OF MAIN COLD FRONT. HAVE THEREFORE ADDED SOME
LOW CHANCE POPS BACK TO FORECAST SUNDAY...ESPECIALLY NORTH AND
EAST WHERE STRONGER INFLUENCE OF PV ANOMALY SEEMS TO BE FOCUSED
WITH AGREEMENT AMONG THE MODELS. PASSAGE OF THIS FEATURE SHOULD
THEN LEAD TO CLEARING SKIES AND COOLER TEMPERATURES SUNDAY NIGHT.

MODELS HAVE CONTINUED TO TREND WARMER POST FRONTAL WITH MODIFIED
AIRMASS AND DEEPER TROUGH AXIS TO OUR EAST MONDAY. SURFACE HIGH
PRESSURE WILL SETTLE IN MONDAY AND CONTINUE THROUGH THE END OF
THE WEEK WITH A MODERATING TEMPERATURE TREND. EXPECT TEMPS
SIMILAR TO LAST FEW DAYS WITH LOWS IN THE LOWER 40S AND HIGHS IN
THE 60S TO BEGIN THE WEEK BUT WARMING TO LOWS IN THE 50S AND
HIGHS IN THE 70S BY MID TO LATE WEEK. DRY CONDITIONS TO EXIST
WITH RIDGING ALOFT BECOMING ANCHORED RIGHT OVER THE AREA THROUGH
THE WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 809 PM EDT FRI SEP 19 2014

VFR MET CONDITIONS TO DOMINATE THROUGH THE FORECAST PERIOD.
SHARPENING UPSTREAM TROF TO BRING INCREASE IN DEEP LAYER SHEAR TO
REGION SAT AFTERNOON. CONCERN CONTINUES TO REVOLVE AROUND DEGREE
OF INSTABILITY AS ANTICIPATED EARLY MORNING DECAY OF UPSTREAM
CONVECTION MAY INHIBIT SFC HEATING. FOR NOW WILL INTRODUCE AS
VCTS LATE IN FORECAST PERIOD AT KSBN WITH KFWA CONCVECTION FREE
DUE TO BOTH LATER TIMING AND PREVALENT HEIGHT FALL CENTROID TRACK
REMAINING WELL NORTH /NERN WI MIDDAY INTO LAKE HURON SAT
EVENING/.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
     SATURDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...LOTHAMER
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIWX 192108
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
508 PM EDT FRI SEP 19 2014

.SYNOPSIS...
ISSUED AT 458 PM EDT FRI SEP 19 2014

HIGH PRESSURE CURRENTLY OVER THE AREA WILL CONTINUE TO MOVE
EASTWARD THROUGH TONIGHT AND THEN EXPECT AN UPPER LEVEL
DISTURBANCE TO MOVE THROUGH TOMORROW. SCATTERED SHOWERS AND
THUNDERSTORMS MAY MOVE INTO THE SOUTHERN GREAT LAKES TOMORROW
MORNING...BUT THE COVERAGE OF SHOWERS AND THUNDERSTORMS IS
EXPECTED TO INCREASE LATER TOMORROW AFTERNOON INTO TOMORROW EVENING.
LOW TEMPERATURES TONIGHT WILL BE IN THE LOWER TO MIDDLE 50S. HIGH
TEMPERATURES TOMORROW WILL BE IN THE UPPER 70S TO LOWER 80S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

CONVECTIVE POTENTIAL ON SATURDAY/SATURDAY NIGHT WILL CONTINUE TO BE
THE PRIMARY FOCUS OF THE SHORT TERM.

IN THE MEANTIME...BROAD LOW AMPLITUDE UPPER LEVEL RIDGING WILL
QUICKLY TRANSLATE EASTWARD ACROSS THE GREAT LAKES/OHIO VALLEY THIS
MORNING WITH CONTINUED SLOW EASTWARD MIGRATION OF LOW LEVEL
ANTICYCLONE NORTHEAST CONUS/SOUTHEAST CANADA. A 50-60 KNOT LLJ IS
EXPECTED TO TAKE SHAPE TONIGHT...WITH STRONGEST LOW LEVEL MOIST
TRANSPORT TAKING SHAPE FROM MID MS RIVER VALLEY NORTHEASTWARD INTO
THE WESTERN GREAT LAKES REGION LATER TONIGHT. CONVECTION MAY DEVELOP
IN ASSOCIATION WITH STRENGTHENING LLJ AND WEAK UPPER PERTURBATIONS
ENTERING WESTERN GREAT LAKES OVERNIGHT. HAVE KEPT FORECAST AREA DRY
OVERNIGHT...ALTHOUGH A VERY LOW END CHANCE OF A SHOWER MAY EXIST
ACROSS THE FAR NORTHWEST TOWARD DAYBREAK AS STRONGER LOW/MID LEVEL
THETAE ADVECTION PROGRESSES INTO THE AREA. OTHERWISE FOR
TONIGHT...MID AND HIGH LEVEL CLOUDS WILL BE ON THE INCREASE
PARTICULARLY DURING THE OVERNIGHT HOURS WHICH COMBINED WITH
STRENGTHENING LOW LEVEL WAA WILL PROVIDE MILDER MINS FROM THE MID
TO UPPER 50S...TO THE LOWER 50S OR AROUND 50 EAST.

STILL PLENTY OF UNCERTAINTY REMAINING IN REGARDS TO
CONVECTIVE/SEVERE RISK FOR SATURDAY. CONVECTION MAY BE ONGOING
EARLY SATURDAY MORNING ACROSS THE WESTERN GREAT LAKES IN
ASSOCIATION WITH AFOREMENTIONED LLJ FORCING. WHILE PROPAGATION
VECTORS WOULD TEND TO KEEP THIS ACTIVITY NORTH OF LOCAL
AREA...SOME ADDITIONAL DEVELOPMENT ALONG RESIDUAL OUTFLOW
BOUNDARIES COULD ALLOW FOR A FEW SHOWERS/ISOLATED STORMS TO WORK
INTO FAR NORTHWEST PORTIONS OF THE AREA AFTER DAYBREAK...BUT
CONFIDENCE IN THIS SCENARIO IS LOW. NEXT UPSTREAM MID LEVEL TROUGH
WILL APPROACH THE GREAT LAKES LATE SATURDAY MORNING ALLOWING FOR
AXIS OF STRONG LOW LEVEL MOISTURE CONVERGENCE TO SHIFT ACROSS
APPROXIMATELY NORTHERN HALF OF THE AREA. AS PREVIOUS DISCUSSION
MENTIONED...AVAILABLE INSTABILITY DURING THE DAY SATURDAY WILL BE
HIGHLY SENSITIVE TO NEAR SFC/SFC TEMPERATURES...AND GIVEN THE
ABOVE INCREASE IN FORCING...SOME POSSIBILITY EXISTS FOR THIS
INSTABILITY TO BE TEMPERED. WHILE MOISTURE TRANSPORT WILL BE
STRONG PRECEDING THE FRONT...NAM MAY BE A BIT AGGRESSIVE WITH SFC
DEW POINTS...AND THUS A BIT ON THE AGGRESSIVE SIDE WITH INSTABILITY
PROGS. NEVERTHELESS..GIVEN STEEPISH MID LEVEL LAPSE RATES...SURFACE
BASED CAPES ON THE ORDER OF 750-1500 J/KG AT LEAST APPEAR TO BE A
POSSIBILITY DEPENDING ON EXTENT OF CLOUD COVER. DEEP LAYER SHEAR
AND 0-3 KM SHEAR VECTORS SHOULD STEADILY STRENGTHEN DURING THE DAY
AS BELT OF STRONGER MID/UPPER LEVEL WESTERLIES PROGRESSES THROUGH
BASE OF THE MID LEVEL TROUGH. GIVEN LOW/MODERATE INSTABILITY AND HIGH
SHEAR ENVIRONMENT...CANNOT RULE OUT AT LEAST AN ISOLD SEVERE
THREAT (MAINLY ISOLD DAMAGING WIND GUSTS) DEPENDING ON HOW
INSTABILITY EVOLVES GIVEN STRENGTHENING BACKGROUND WIND FIELD AND
UNIDIRECTIONAL NATURE TO FLOW. WINDOW OF SEVERE POTENTIAL SHOULD
BE SOMEWHAT LIMITED...WITH PRELIMINARY INDICATIONS IN THE 21Z-03Z
TIMEFRAME.

A PUNCH OF DRIER MID LEVEL AIR TO ADVECT INTO THE AREA
OVERNIGHT...BUT SECONDARY AXIS OF PREFRONTAL LOW LEVEL MOISTURE
POOLING SHOULD KEEP ENOUGH ELEVATED INSTABILITY IN PLACE FOR
CONTINUED SCATTERED SHOWER/THUNDERSTORMS DURING THE OVERNIGHT HOURS
AS NEXT UPSTREAM UPPER LEVEL TROUGH APPROACHES. SLIGHTLY MORE
DELAYED FROPA EARLY SUNDAY MORNING AND ABUNDANT CLOUD COVER WILL
PROVIDE MILDER MINS IN THE LOWER AND MID 60S.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

LONG TERM PERIOD BEGINS SUNDAY MORNING WITH DRY SLOT BEHIND COLD
FRONT INITIALLY OVER THE AREA. MOST PCPN ASSOCIATED WITH FRONTAL
BOUNDARY SHOULD BE EXITING THE AREA BY 12Z. MODEL SOUNDINGS INDICATE
POST FRONTAL INVERSION WITH TRAPPED LOW LEVEL MOISTURE SUGGESTING
LINGERING CLOUD COVER INTO EARLY AFTERNOON. WE HAVE BEEN DISCUSSING
THE POSSIBILITY OF SHOWERS WITH SECONDARY SHORT WAVE FOR SEVERAL
DAYS. LATEST MODEL GUIDANCE SHOWING A RATHER STRONG PV ANOMALY NOW
DROPPING INTO THE AREA BY MID DAY WITH STRONG DPVA WITHIN THIS SHORT
WAVE TROUGH. DEEPER MOISTURE IS CERTAINLY SCOURED AS THIS FEATURE
NEARS BUT CONCERN LIES WITH TRAPPED LOW LEVEL MOISTURE AND ANY WEAK
LAKE CONTRIBUTION PROVIDING ENOUGH MOISTURE WITH LARGE SCALE LIFT TO
PRODUCE SOME LIGHT SHOWERS. SOUNDINGS ALSO INDICATE A BIT OF
ELEVATED INSTABILITY IN WAKE OF MAIN COLD FRONT. HAVE THEREFORE
ADDED SOME LOW CHANCE POPS BACK TO FORECAST SUNDAY...ESPECIALLY
NORTH AND EAST WHERE STRONGER INFLUENCE OF PV ANOMALY SEEMS TO BE
FOCUSED WITH AGREEMENT AMONG THE MODELS. PASSAGE OF THIS FEATURE
SHOULD THEN LEAD TO CLEARING SKIES AND COOLER TEMPERATURES
SUNDAY NIGHT.

MODELS HAVE CONTINUED TO TREND WARMER POST FRONTAL WITH MODIFIED
AIRMASS AND DEEPER TROUGH AXIS TO OUR EAST MONDAY. SURFACE HIGH
PRESSURE WILL SETTLE IN MONDAY AND CONTINUE THROUGH THE END OF THE
WEEK WITH A MODERATING TEMPERATURE TREND. EXPECT TEMPS SIMILAR TO
LAST FEW DAYS WITH LOWS IN THE LOWER 40S AND HIGHS IN THE 60S TO
BEGIN THE WEEK BUT WARMING TO LOWS IN THE 50S AND HIGHS IN THE 70S
BY MID TO LATE WEEK. DRY CONDITIONS TO EXIST WITH RIDGING ALOFT
BECOMING ANCHORED RIGHT OVER THE AREA THROUGH THE WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 145 PM EDT FRI SEP 19 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE BULK OF THIS FORECAST
PERIOD. LARGE LOW LEVEL ANTICYCLONE ACROSS EASTERN CONUS WILL
CONTINUE TO BE THE PRIMARY FEATURE CONTROLLING WEATHER ACROSS
NORTHERN INDIANA THROUGH TONIGHT. SOUTHEAST WINDS ON THE WESTERN
PERIPHERY OF THIS HIGH PRESSURE WILL CONTINUE THROUGH THE
PERIOD...VEERING MORE SOUTHERLY TONIGHT AS NEXT TROUGH OF LOW
PRESSURE TRACKS INTO THE UPPER MIDWEST. STRONG LOW LEVEL THETAE
ADVECTION PRECEDING COLD FRONT IN ASSOCIATION WITH NEXT MID/UPPER
LEVEL SYSTEM WILL WORK ACROSS NORTHERN INDIANA SATURDAY MORNING.
SOME SHOWERS MAY DEVELOP IN ASSOCIATION WITH THIS STRONG LOW LEVEL
THETAE ADVECTION...BUT GREATER CHANCES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO HOLD OFF UNTIL AFTER 18Z AS
MID/UPPER LEVEL TROUGH AXIS APPROACHES WESTERN GREAT LAKES REGION.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
     SATURDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...LOTHAMER
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 192108
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
508 PM EDT FRI SEP 19 2014

.SYNOPSIS...
ISSUED AT 458 PM EDT FRI SEP 19 2014

HIGH PRESSURE CURRENTLY OVER THE AREA WILL CONTINUE TO MOVE
EASTWARD THROUGH TONIGHT AND THEN EXPECT AN UPPER LEVEL
DISTURBANCE TO MOVE THROUGH TOMORROW. SCATTERED SHOWERS AND
THUNDERSTORMS MAY MOVE INTO THE SOUTHERN GREAT LAKES TOMORROW
MORNING...BUT THE COVERAGE OF SHOWERS AND THUNDERSTORMS IS
EXPECTED TO INCREASE LATER TOMORROW AFTERNOON INTO TOMORROW EVENING.
LOW TEMPERATURES TONIGHT WILL BE IN THE LOWER TO MIDDLE 50S. HIGH
TEMPERATURES TOMORROW WILL BE IN THE UPPER 70S TO LOWER 80S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

CONVECTIVE POTENTIAL ON SATURDAY/SATURDAY NIGHT WILL CONTINUE TO BE
THE PRIMARY FOCUS OF THE SHORT TERM.

IN THE MEANTIME...BROAD LOW AMPLITUDE UPPER LEVEL RIDGING WILL
QUICKLY TRANSLATE EASTWARD ACROSS THE GREAT LAKES/OHIO VALLEY THIS
MORNING WITH CONTINUED SLOW EASTWARD MIGRATION OF LOW LEVEL
ANTICYCLONE NORTHEAST CONUS/SOUTHEAST CANADA. A 50-60 KNOT LLJ IS
EXPECTED TO TAKE SHAPE TONIGHT...WITH STRONGEST LOW LEVEL MOIST
TRANSPORT TAKING SHAPE FROM MID MS RIVER VALLEY NORTHEASTWARD INTO
THE WESTERN GREAT LAKES REGION LATER TONIGHT. CONVECTION MAY DEVELOP
IN ASSOCIATION WITH STRENGTHENING LLJ AND WEAK UPPER PERTURBATIONS
ENTERING WESTERN GREAT LAKES OVERNIGHT. HAVE KEPT FORECAST AREA DRY
OVERNIGHT...ALTHOUGH A VERY LOW END CHANCE OF A SHOWER MAY EXIST
ACROSS THE FAR NORTHWEST TOWARD DAYBREAK AS STRONGER LOW/MID LEVEL
THETAE ADVECTION PROGRESSES INTO THE AREA. OTHERWISE FOR
TONIGHT...MID AND HIGH LEVEL CLOUDS WILL BE ON THE INCREASE
PARTICULARLY DURING THE OVERNIGHT HOURS WHICH COMBINED WITH
STRENGTHENING LOW LEVEL WAA WILL PROVIDE MILDER MINS FROM THE MID
TO UPPER 50S...TO THE LOWER 50S OR AROUND 50 EAST.

STILL PLENTY OF UNCERTAINTY REMAINING IN REGARDS TO
CONVECTIVE/SEVERE RISK FOR SATURDAY. CONVECTION MAY BE ONGOING
EARLY SATURDAY MORNING ACROSS THE WESTERN GREAT LAKES IN
ASSOCIATION WITH AFOREMENTIONED LLJ FORCING. WHILE PROPAGATION
VECTORS WOULD TEND TO KEEP THIS ACTIVITY NORTH OF LOCAL
AREA...SOME ADDITIONAL DEVELOPMENT ALONG RESIDUAL OUTFLOW
BOUNDARIES COULD ALLOW FOR A FEW SHOWERS/ISOLATED STORMS TO WORK
INTO FAR NORTHWEST PORTIONS OF THE AREA AFTER DAYBREAK...BUT
CONFIDENCE IN THIS SCENARIO IS LOW. NEXT UPSTREAM MID LEVEL TROUGH
WILL APPROACH THE GREAT LAKES LATE SATURDAY MORNING ALLOWING FOR
AXIS OF STRONG LOW LEVEL MOISTURE CONVERGENCE TO SHIFT ACROSS
APPROXIMATELY NORTHERN HALF OF THE AREA. AS PREVIOUS DISCUSSION
MENTIONED...AVAILABLE INSTABILITY DURING THE DAY SATURDAY WILL BE
HIGHLY SENSITIVE TO NEAR SFC/SFC TEMPERATURES...AND GIVEN THE
ABOVE INCREASE IN FORCING...SOME POSSIBILITY EXISTS FOR THIS
INSTABILITY TO BE TEMPERED. WHILE MOISTURE TRANSPORT WILL BE
STRONG PRECEDING THE FRONT...NAM MAY BE A BIT AGGRESSIVE WITH SFC
DEW POINTS...AND THUS A BIT ON THE AGGRESSIVE SIDE WITH INSTABILITY
PROGS. NEVERTHELESS..GIVEN STEEPISH MID LEVEL LAPSE RATES...SURFACE
BASED CAPES ON THE ORDER OF 750-1500 J/KG AT LEAST APPEAR TO BE A
POSSIBILITY DEPENDING ON EXTENT OF CLOUD COVER. DEEP LAYER SHEAR
AND 0-3 KM SHEAR VECTORS SHOULD STEADILY STRENGTHEN DURING THE DAY
AS BELT OF STRONGER MID/UPPER LEVEL WESTERLIES PROGRESSES THROUGH
BASE OF THE MID LEVEL TROUGH. GIVEN LOW/MODERATE INSTABILITY AND HIGH
SHEAR ENVIRONMENT...CANNOT RULE OUT AT LEAST AN ISOLD SEVERE
THREAT (MAINLY ISOLD DAMAGING WIND GUSTS) DEPENDING ON HOW
INSTABILITY EVOLVES GIVEN STRENGTHENING BACKGROUND WIND FIELD AND
UNIDIRECTIONAL NATURE TO FLOW. WINDOW OF SEVERE POTENTIAL SHOULD
BE SOMEWHAT LIMITED...WITH PRELIMINARY INDICATIONS IN THE 21Z-03Z
TIMEFRAME.

A PUNCH OF DRIER MID LEVEL AIR TO ADVECT INTO THE AREA
OVERNIGHT...BUT SECONDARY AXIS OF PREFRONTAL LOW LEVEL MOISTURE
POOLING SHOULD KEEP ENOUGH ELEVATED INSTABILITY IN PLACE FOR
CONTINUED SCATTERED SHOWER/THUNDERSTORMS DURING THE OVERNIGHT HOURS
AS NEXT UPSTREAM UPPER LEVEL TROUGH APPROACHES. SLIGHTLY MORE
DELAYED FROPA EARLY SUNDAY MORNING AND ABUNDANT CLOUD COVER WILL
PROVIDE MILDER MINS IN THE LOWER AND MID 60S.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

LONG TERM PERIOD BEGINS SUNDAY MORNING WITH DRY SLOT BEHIND COLD
FRONT INITIALLY OVER THE AREA. MOST PCPN ASSOCIATED WITH FRONTAL
BOUNDARY SHOULD BE EXITING THE AREA BY 12Z. MODEL SOUNDINGS INDICATE
POST FRONTAL INVERSION WITH TRAPPED LOW LEVEL MOISTURE SUGGESTING
LINGERING CLOUD COVER INTO EARLY AFTERNOON. WE HAVE BEEN DISCUSSING
THE POSSIBILITY OF SHOWERS WITH SECONDARY SHORT WAVE FOR SEVERAL
DAYS. LATEST MODEL GUIDANCE SHOWING A RATHER STRONG PV ANOMALY NOW
DROPPING INTO THE AREA BY MID DAY WITH STRONG DPVA WITHIN THIS SHORT
WAVE TROUGH. DEEPER MOISTURE IS CERTAINLY SCOURED AS THIS FEATURE
NEARS BUT CONCERN LIES WITH TRAPPED LOW LEVEL MOISTURE AND ANY WEAK
LAKE CONTRIBUTION PROVIDING ENOUGH MOISTURE WITH LARGE SCALE LIFT TO
PRODUCE SOME LIGHT SHOWERS. SOUNDINGS ALSO INDICATE A BIT OF
ELEVATED INSTABILITY IN WAKE OF MAIN COLD FRONT. HAVE THEREFORE
ADDED SOME LOW CHANCE POPS BACK TO FORECAST SUNDAY...ESPECIALLY
NORTH AND EAST WHERE STRONGER INFLUENCE OF PV ANOMALY SEEMS TO BE
FOCUSED WITH AGREEMENT AMONG THE MODELS. PASSAGE OF THIS FEATURE
SHOULD THEN LEAD TO CLEARING SKIES AND COOLER TEMPERATURES
SUNDAY NIGHT.

MODELS HAVE CONTINUED TO TREND WARMER POST FRONTAL WITH MODIFIED
AIRMASS AND DEEPER TROUGH AXIS TO OUR EAST MONDAY. SURFACE HIGH
PRESSURE WILL SETTLE IN MONDAY AND CONTINUE THROUGH THE END OF THE
WEEK WITH A MODERATING TEMPERATURE TREND. EXPECT TEMPS SIMILAR TO
LAST FEW DAYS WITH LOWS IN THE LOWER 40S AND HIGHS IN THE 60S TO
BEGIN THE WEEK BUT WARMING TO LOWS IN THE 50S AND HIGHS IN THE 70S
BY MID TO LATE WEEK. DRY CONDITIONS TO EXIST WITH RIDGING ALOFT
BECOMING ANCHORED RIGHT OVER THE AREA THROUGH THE WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 145 PM EDT FRI SEP 19 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE BULK OF THIS FORECAST
PERIOD. LARGE LOW LEVEL ANTICYCLONE ACROSS EASTERN CONUS WILL
CONTINUE TO BE THE PRIMARY FEATURE CONTROLLING WEATHER ACROSS
NORTHERN INDIANA THROUGH TONIGHT. SOUTHEAST WINDS ON THE WESTERN
PERIPHERY OF THIS HIGH PRESSURE WILL CONTINUE THROUGH THE
PERIOD...VEERING MORE SOUTHERLY TONIGHT AS NEXT TROUGH OF LOW
PRESSURE TRACKS INTO THE UPPER MIDWEST. STRONG LOW LEVEL THETAE
ADVECTION PRECEDING COLD FRONT IN ASSOCIATION WITH NEXT MID/UPPER
LEVEL SYSTEM WILL WORK ACROSS NORTHERN INDIANA SATURDAY MORNING.
SOME SHOWERS MAY DEVELOP IN ASSOCIATION WITH THIS STRONG LOW LEVEL
THETAE ADVECTION...BUT GREATER CHANCES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO HOLD OFF UNTIL AFTER 18Z AS
MID/UPPER LEVEL TROUGH AXIS APPROACHES WESTERN GREAT LAKES REGION.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
     SATURDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...LOTHAMER
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 192011
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
411 PM EDT FRI SEP 19 2014

.SYNOPSIS...
ISSUED AT 353 PM EDT FRI SEP 19 2014

HIGH PRESSURE ACROSS THE NORTHEAST UNITED STATES WILL CONTINUE TO
SHIFT OFF TO THE EAST TONIGHT. SOUTH WINDS WILL BRING WARMER AIR
NORTHWARD TONIGHT AND SATURDAY...ALONG WITH AN INCREASE IN
MOISTURE. SCATTERED SHOWERS AND THUNDERSTORMS MAY MOVE INTO THE
SOUTHERN GREAT LAKES SATURDAY MORNING...BUT THE COVERAGE OF
SHOWERS AND THUNDERSTORMS IS EXPECTED TO INCREASE LATER SATURDAY
AFTERNOON INTO SATURDAY EVENING AS AN UPPER LEVEL DISTURBANCE
MOVES THROUGH. A SECOND DISTURBANCE WILL BRING A CONTINUED CHANCE
OF SHOWERS AND THUNDERSTORMS LATE SATURDAY NIGHT INTO SUNDAY WITH
DRY CONDITIONS RETURNING SUNDAY NIGHT. LOWS TONIGHT WILL RANGE
FROM AROUND 60 ACROSS FAR NORTHEAST ILLINOIS...TO AROUND 50 ACROSS
SOUTHEAST LOWER MICHIGAN AND NORTHWEST OHIO. HIGH TEMPERATURES ON
SATURDAY WILL RANGE FROM THE MID 70S TO LOWER 80S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

CONVECTIVE POTENTIAL ON SATURDAY/SATURDAY NIGHT WILL CONTINUE TO BE
THE PRIMARY FOCUS OF THE SHORT TERM.

IN THE MEANTIME...BROAD LOW AMPLITUDE UPPER LEVEL RIDGING WILL
QUICKLY TRANSLATE EASTWARD ACROSS THE GREAT LAKES/OHIO VALLEY THIS
MORNING WITH CONTINUED SLOW EASTWARD MIGRATION OF LOW LEVEL
ANTICYCLONE NORTHEAST CONUS/SOUTHEAST CANADA. A 50-60 KNOT LLJ IS
EXPECTED TO TAKE SHAPE TONIGHT...WITH STRONGEST LOW LEVEL MOIST
TRANSPORT TAKING SHAPE FROM MID MS RIVER VALLEY NORTHEASTWARD INTO
THE WESTERN GREAT LAKES REGION LATER TONIGHT. CONVECTION MAY DEVELOP
IN ASSOCIATION WITH STRENGTHENING LLJ AND WEAK UPPER PERTURBATIONS
ENTERING WESTERN GREAT LAKES OVERNIGHT. HAVE KEPT FORECAST AREA DRY
OVERNIGHT...ALTHOUGH A VERY LOW END CHANCE OF A SHOWER MAY EXIST
ACROSS THE FAR NORTHWEST TOWARD DAYBREAK AS STRONGER LOW/MID LEVEL
THETAE ADVECTION PROGRESSES INTO THE AREA. OTHERWISE FOR
TONIGHT...MID AND HIGH LEVEL CLOUDS WILL BE ON THE INCREASE
PARTICULARLY DURING THE OVERNIGHT HOURS WHICH COMBINED WITH
STRENGTHENING LOW LEVEL WAA WILL PROVIDE MILDER MINS FROM THE MID
TO UPPER 50S...TO THE LOWER 50S OR AROUND 50 EAST.

STILL PLENTY OF UNCERTAINTY REMAINING IN REGARDS TO
CONVECTIVE/SEVERE RISK FOR SATURDAY. CONVECTION MAY BE ONGOING
EARLY SATURDAY MORNING ACROSS THE WESTERN GREAT LAKES IN
ASSOCIATION WITH AFOREMENTIONED LLJ FORCING. WHILE PROPAGATION
VECTORS WOULD TEND TO KEEP THIS ACTIVITY NORTH OF LOCAL
AREA...SOME ADDITIONAL DEVELOPMENT ALONG RESIDUAL OUTFLOW
BOUNDARIES COULD ALLOW FOR A FEW SHOWERS/ISOLATED STORMS TO WORK
INTO FAR NORTHWEST PORTIONS OF THE AREA AFTER DAYBREAK...BUT
CONFIDENCE IN THIS SCENARIO IS LOW. NEXT UPSTREAM MID LEVEL TROUGH
WILL APPROACH THE GREAT LAKES LATE SATURDAY MORNING ALLOWING FOR
AXIS OF STRONG LOW LEVEL MOISTURE CONVERGENCE TO SHIFT ACROSS
APPROXIMATELY NORTHERN HALF OF THE AREA. AS PREVIOUS DISCUSSION
MENTIONED...AVAILABLE INSTABILITY DURING THE DAY SATURDAY WILL BE
HIGHLY SENSITIVE TO NEAR SFC/SFC TEMPERATURES...AND GIVEN THE
ABOVE INCREASE IN FORCING...SOME POSSIBILITY EXISTS FOR THIS
INSTABILITY TO BE TEMPERED. WHILE MOISTURE TRANSPORT WILL BE
STRONG PRECEDING THE FRONT...NAM MAY BE A BIT AGGRESSIVE WITH SFC
DEW POINTS...AND THUS A BIT ON THE AGGRESSIVE SIDE WITH INSTABILITY
PROGS. NEVERTHELESS..GIVEN STEEPISH MID LEVEL LAPSE RATES...SURFACE
BASED CAPES ON THE ORDER OF 750-1500 J/KG AT LEAST APPEAR TO BE A
POSSIBILITY DEPENDING ON EXTENT OF CLOUD COVER. DEEP LAYER SHEAR
AND 0-3 KM SHEAR VECTORS SHOULD STEADILY STRENGTHEN DURING THE DAY
AS BELT OF STRONGER MID/UPPER LEVEL WESTERLIES PROGRESSES THROUGH
BASE OF THE MID LEVEL TROUGH. GIVEN LOW/MODERATE INSTABILITY AND HIGH
SHEAR ENVIRONMENT...CANNOT RULE OUT AT LEAST AN ISOLD SEVERE
THREAT (MAINLY ISOLD DAMAGING WIND GUSTS) DEPENDING ON HOW
INSTABILITY EVOLVES GIVEN STRENGTHENING BACKGROUND WIND FIELD AND
UNIDIRECTIONAL NATURE TO FLOW. WINDOW OF SEVERE POTENTIAL SHOULD
BE SOMEWHAT LIMITED...WITH PRELIMINARY INDICATIONS IN THE 21Z-03Z
TIMEFRAME.

A PUNCH OF DRIER MID LEVEL AIR TO ADVECT INTO THE AREA
OVERNIGHT...BUT SECONDARY AXIS OF PREFRONTAL LOW LEVEL MOISTURE
POOLING SHOULD KEEP ENOUGH ELEVATED INSTABILITY IN PLACE FOR
CONTINUED SCATTERED SHOWER/THUNDERSTORMS DURING THE OVERNIGHT HOURS
AS NEXT UPSTREAM UPPER LEVEL TROUGH APPROACHES. SLIGHTLY MORE
DELAYED FROPA EARLY SUNDAY MORNING AND ABUNDANT CLOUD COVER WILL
PROVIDE MILDER MINS IN THE LOWER AND MID 60S.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

LONG TERM PERIOD BEGINS SUNDAY MORNING WITH DRY SLOT BEHIND COLD
FRONT INITIALLY OVER THE AREA. MOST PCPN ASSOCIATED WITH FRONTAL
BOUNDARY SHOULD BE EXITING THE AREA BY 12Z. MODEL SOUNDINGS INDICATE
POST FRONTAL INVERSION WITH TRAPPED LOW LEVEL MOISTURE SUGGESTING
LINGERING CLOUD COVER INTO EARLY AFTERNOON. WE HAVE BEEN DISCUSSING
THE POSSIBILITY OF SHOWERS WITH SECONDARY SHORT WAVE FOR SEVERAL
DAYS. LATEST MODEL GUIDANCE SHOWING A RATHER STRONG PV ANOMALY NOW
DROPPING INTO THE AREA BY MID DAY WITH STRONG DPVA WITHIN THIS SHORT
WAVE TROUGH. DEEPER MOISTURE IS CERTAINLY SCOURED AS THIS FEATURE
NEARS BUT CONCERN LIES WITH TRAPPED LOW LEVEL MOISTURE AND ANY WEAK
LAKE CONTRIBUTION PROVIDING ENOUGH MOISTURE WITH LARGE SCALE LIFT TO
PRODUCE SOME LIGHT SHOWERS. SOUNDINGS ALSO INDICATE A BIT OF
ELEVATED INSTABILITY IN WAKE OF MAIN COLD FRONT. HAVE THEREFORE
ADDED SOME LOW CHANCE POPS BACK TO FORECAST SUNDAY...ESPECIALLY
NORTH AND EAST WHERE STRONGER INFLUENCE OF PV ANOMALY SEEMS TO BE
FOCUSED WITH AGREEMENT AMONG THE MODELS. PASSAGE OF THIS FEATURE
SHOULD THEN LEAD TO CLEARING SKIES AND COOLER TEMPERATURES
SUNDAY NIGHT.

MODELS HAVE CONTINUED TO TREND WARMER POST FRONTAL WITH MODIFIED
AIRMASS AND DEEPER TROUGH AXIS TO OUR EAST MONDAY. SURFACE HIGH
PRESSURE WILL SETTLE IN MONDAY AND CONTINUE THROUGH THE END OF THE
WEEK WITH A MODERATING TEMPERATURE TREND. EXPECT TEMPS SIMILAR TO
LAST FEW DAYS WITH LOWS IN THE LOWER 40S AND HIGHS IN THE 60S TO
BEGIN THE WEEK BUT WARMING TO LOWS IN THE 50S AND HIGHS IN THE 70S
BY MID TO LATE WEEK. DRY CONDITIONS TO EXIST WITH RIDGING ALOFT
BECOMING ANCHORED RIGHT OVER THE AREA THROUGH THE WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 145 PM EDT FRI SEP 19 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE BULK OF THIS FORECAST
PERIOD. LARGE LOW LEVEL ANTICYCLONE ACROSS EASTERN CONUS WILL
CONTINUE TO BE THE PRIMARY FEATURE CONTROLLING WEATHER ACROSS
NORTHERN INDIANA THROUGH TONIGHT. SOUTHEAST WINDS ON THE WESTERN
PERIPHERY OF THIS HIGH PRESSURE WILL CONTINUE THROUGH THE
PERIOD...VEERING MORE SOUTHERLY TONIGHT AS NEXT TROUGH OF LOW
PRESSURE TRACKS INTO THE UPPER MIDWEST. STRONG LOW LEVEL THETAE
ADVECTION PRECEDING COLD FRONT IN ASSOCIATION WITH NEXT MID/UPPER
LEVEL SYSTEM WILL WORK ACROSS NORTHERN INDIANA SATURDAY MORNING.
SOME SHOWERS MAY DEVELOP IN ASSOCIATION WITH THIS STRONG LOW LEVEL
THETAE ADVECTION...BUT GREATER CHANCES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO HOLD OFF UNTIL AFTER 18Z AS
MID/UPPER LEVEL TROUGH AXIS APPROACHES WESTERN GREAT LAKES REGION.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
     SATURDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 192011
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
411 PM EDT FRI SEP 19 2014

.SYNOPSIS...
ISSUED AT 353 PM EDT FRI SEP 19 2014

HIGH PRESSURE ACROSS THE NORTHEAST UNITED STATES WILL CONTINUE TO
SHIFT OFF TO THE EAST TONIGHT. SOUTH WINDS WILL BRING WARMER AIR
NORTHWARD TONIGHT AND SATURDAY...ALONG WITH AN INCREASE IN
MOISTURE. SCATTERED SHOWERS AND THUNDERSTORMS MAY MOVE INTO THE
SOUTHERN GREAT LAKES SATURDAY MORNING...BUT THE COVERAGE OF
SHOWERS AND THUNDERSTORMS IS EXPECTED TO INCREASE LATER SATURDAY
AFTERNOON INTO SATURDAY EVENING AS AN UPPER LEVEL DISTURBANCE
MOVES THROUGH. A SECOND DISTURBANCE WILL BRING A CONTINUED CHANCE
OF SHOWERS AND THUNDERSTORMS LATE SATURDAY NIGHT INTO SUNDAY WITH
DRY CONDITIONS RETURNING SUNDAY NIGHT. LOWS TONIGHT WILL RANGE
FROM AROUND 60 ACROSS FAR NORTHEAST ILLINOIS...TO AROUND 50 ACROSS
SOUTHEAST LOWER MICHIGAN AND NORTHWEST OHIO. HIGH TEMPERATURES ON
SATURDAY WILL RANGE FROM THE MID 70S TO LOWER 80S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

CONVECTIVE POTENTIAL ON SATURDAY/SATURDAY NIGHT WILL CONTINUE TO BE
THE PRIMARY FOCUS OF THE SHORT TERM.

IN THE MEANTIME...BROAD LOW AMPLITUDE UPPER LEVEL RIDGING WILL
QUICKLY TRANSLATE EASTWARD ACROSS THE GREAT LAKES/OHIO VALLEY THIS
MORNING WITH CONTINUED SLOW EASTWARD MIGRATION OF LOW LEVEL
ANTICYCLONE NORTHEAST CONUS/SOUTHEAST CANADA. A 50-60 KNOT LLJ IS
EXPECTED TO TAKE SHAPE TONIGHT...WITH STRONGEST LOW LEVEL MOIST
TRANSPORT TAKING SHAPE FROM MID MS RIVER VALLEY NORTHEASTWARD INTO
THE WESTERN GREAT LAKES REGION LATER TONIGHT. CONVECTION MAY DEVELOP
IN ASSOCIATION WITH STRENGTHENING LLJ AND WEAK UPPER PERTURBATIONS
ENTERING WESTERN GREAT LAKES OVERNIGHT. HAVE KEPT FORECAST AREA DRY
OVERNIGHT...ALTHOUGH A VERY LOW END CHANCE OF A SHOWER MAY EXIST
ACROSS THE FAR NORTHWEST TOWARD DAYBREAK AS STRONGER LOW/MID LEVEL
THETAE ADVECTION PROGRESSES INTO THE AREA. OTHERWISE FOR
TONIGHT...MID AND HIGH LEVEL CLOUDS WILL BE ON THE INCREASE
PARTICULARLY DURING THE OVERNIGHT HOURS WHICH COMBINED WITH
STRENGTHENING LOW LEVEL WAA WILL PROVIDE MILDER MINS FROM THE MID
TO UPPER 50S...TO THE LOWER 50S OR AROUND 50 EAST.

STILL PLENTY OF UNCERTAINTY REMAINING IN REGARDS TO
CONVECTIVE/SEVERE RISK FOR SATURDAY. CONVECTION MAY BE ONGOING
EARLY SATURDAY MORNING ACROSS THE WESTERN GREAT LAKES IN
ASSOCIATION WITH AFOREMENTIONED LLJ FORCING. WHILE PROPAGATION
VECTORS WOULD TEND TO KEEP THIS ACTIVITY NORTH OF LOCAL
AREA...SOME ADDITIONAL DEVELOPMENT ALONG RESIDUAL OUTFLOW
BOUNDARIES COULD ALLOW FOR A FEW SHOWERS/ISOLATED STORMS TO WORK
INTO FAR NORTHWEST PORTIONS OF THE AREA AFTER DAYBREAK...BUT
CONFIDENCE IN THIS SCENARIO IS LOW. NEXT UPSTREAM MID LEVEL TROUGH
WILL APPROACH THE GREAT LAKES LATE SATURDAY MORNING ALLOWING FOR
AXIS OF STRONG LOW LEVEL MOISTURE CONVERGENCE TO SHIFT ACROSS
APPROXIMATELY NORTHERN HALF OF THE AREA. AS PREVIOUS DISCUSSION
MENTIONED...AVAILABLE INSTABILITY DURING THE DAY SATURDAY WILL BE
HIGHLY SENSITIVE TO NEAR SFC/SFC TEMPERATURES...AND GIVEN THE
ABOVE INCREASE IN FORCING...SOME POSSIBILITY EXISTS FOR THIS
INSTABILITY TO BE TEMPERED. WHILE MOISTURE TRANSPORT WILL BE
STRONG PRECEDING THE FRONT...NAM MAY BE A BIT AGGRESSIVE WITH SFC
DEW POINTS...AND THUS A BIT ON THE AGGRESSIVE SIDE WITH INSTABILITY
PROGS. NEVERTHELESS..GIVEN STEEPISH MID LEVEL LAPSE RATES...SURFACE
BASED CAPES ON THE ORDER OF 750-1500 J/KG AT LEAST APPEAR TO BE A
POSSIBILITY DEPENDING ON EXTENT OF CLOUD COVER. DEEP LAYER SHEAR
AND 0-3 KM SHEAR VECTORS SHOULD STEADILY STRENGTHEN DURING THE DAY
AS BELT OF STRONGER MID/UPPER LEVEL WESTERLIES PROGRESSES THROUGH
BASE OF THE MID LEVEL TROUGH. GIVEN LOW/MODERATE INSTABILITY AND HIGH
SHEAR ENVIRONMENT...CANNOT RULE OUT AT LEAST AN ISOLD SEVERE
THREAT (MAINLY ISOLD DAMAGING WIND GUSTS) DEPENDING ON HOW
INSTABILITY EVOLVES GIVEN STRENGTHENING BACKGROUND WIND FIELD AND
UNIDIRECTIONAL NATURE TO FLOW. WINDOW OF SEVERE POTENTIAL SHOULD
BE SOMEWHAT LIMITED...WITH PRELIMINARY INDICATIONS IN THE 21Z-03Z
TIMEFRAME.

A PUNCH OF DRIER MID LEVEL AIR TO ADVECT INTO THE AREA
OVERNIGHT...BUT SECONDARY AXIS OF PREFRONTAL LOW LEVEL MOISTURE
POOLING SHOULD KEEP ENOUGH ELEVATED INSTABILITY IN PLACE FOR
CONTINUED SCATTERED SHOWER/THUNDERSTORMS DURING THE OVERNIGHT HOURS
AS NEXT UPSTREAM UPPER LEVEL TROUGH APPROACHES. SLIGHTLY MORE
DELAYED FROPA EARLY SUNDAY MORNING AND ABUNDANT CLOUD COVER WILL
PROVIDE MILDER MINS IN THE LOWER AND MID 60S.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EDT FRI SEP 19 2014

LONG TERM PERIOD BEGINS SUNDAY MORNING WITH DRY SLOT BEHIND COLD
FRONT INITIALLY OVER THE AREA. MOST PCPN ASSOCIATED WITH FRONTAL
BOUNDARY SHOULD BE EXITING THE AREA BY 12Z. MODEL SOUNDINGS INDICATE
POST FRONTAL INVERSION WITH TRAPPED LOW LEVEL MOISTURE SUGGESTING
LINGERING CLOUD COVER INTO EARLY AFTERNOON. WE HAVE BEEN DISCUSSING
THE POSSIBILITY OF SHOWERS WITH SECONDARY SHORT WAVE FOR SEVERAL
DAYS. LATEST MODEL GUIDANCE SHOWING A RATHER STRONG PV ANOMALY NOW
DROPPING INTO THE AREA BY MID DAY WITH STRONG DPVA WITHIN THIS SHORT
WAVE TROUGH. DEEPER MOISTURE IS CERTAINLY SCOURED AS THIS FEATURE
NEARS BUT CONCERN LIES WITH TRAPPED LOW LEVEL MOISTURE AND ANY WEAK
LAKE CONTRIBUTION PROVIDING ENOUGH MOISTURE WITH LARGE SCALE LIFT TO
PRODUCE SOME LIGHT SHOWERS. SOUNDINGS ALSO INDICATE A BIT OF
ELEVATED INSTABILITY IN WAKE OF MAIN COLD FRONT. HAVE THEREFORE
ADDED SOME LOW CHANCE POPS BACK TO FORECAST SUNDAY...ESPECIALLY
NORTH AND EAST WHERE STRONGER INFLUENCE OF PV ANOMALY SEEMS TO BE
FOCUSED WITH AGREEMENT AMONG THE MODELS. PASSAGE OF THIS FEATURE
SHOULD THEN LEAD TO CLEARING SKIES AND COOLER TEMPERATURES
SUNDAY NIGHT.

MODELS HAVE CONTINUED TO TREND WARMER POST FRONTAL WITH MODIFIED
AIRMASS AND DEEPER TROUGH AXIS TO OUR EAST MONDAY. SURFACE HIGH
PRESSURE WILL SETTLE IN MONDAY AND CONTINUE THROUGH THE END OF THE
WEEK WITH A MODERATING TEMPERATURE TREND. EXPECT TEMPS SIMILAR TO
LAST FEW DAYS WITH LOWS IN THE LOWER 40S AND HIGHS IN THE 60S TO
BEGIN THE WEEK BUT WARMING TO LOWS IN THE 50S AND HIGHS IN THE 70S
BY MID TO LATE WEEK. DRY CONDITIONS TO EXIST WITH RIDGING ALOFT
BECOMING ANCHORED RIGHT OVER THE AREA THROUGH THE WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 145 PM EDT FRI SEP 19 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE BULK OF THIS FORECAST
PERIOD. LARGE LOW LEVEL ANTICYCLONE ACROSS EASTERN CONUS WILL
CONTINUE TO BE THE PRIMARY FEATURE CONTROLLING WEATHER ACROSS
NORTHERN INDIANA THROUGH TONIGHT. SOUTHEAST WINDS ON THE WESTERN
PERIPHERY OF THIS HIGH PRESSURE WILL CONTINUE THROUGH THE
PERIOD...VEERING MORE SOUTHERLY TONIGHT AS NEXT TROUGH OF LOW
PRESSURE TRACKS INTO THE UPPER MIDWEST. STRONG LOW LEVEL THETAE
ADVECTION PRECEDING COLD FRONT IN ASSOCIATION WITH NEXT MID/UPPER
LEVEL SYSTEM WILL WORK ACROSS NORTHERN INDIANA SATURDAY MORNING.
SOME SHOWERS MAY DEVELOP IN ASSOCIATION WITH THIS STRONG LOW LEVEL
THETAE ADVECTION...BUT GREATER CHANCES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO HOLD OFF UNTIL AFTER 18Z AS
MID/UPPER LEVEL TROUGH AXIS APPROACHES WESTERN GREAT LAKES REGION.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
     SATURDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...LASHLEY
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIWX 191751
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
151 PM EDT FRI SEP 19 2014

.SYNOPSIS...
ISSUED AT 355 AM EDT FRI SEP 19 2014

HIGH PRESSURE WILL BEGIN TO RETREAT EASTWARD IN ADVANCE OF A
DEVELOPING LOW PRESSURE SYSTEM ACROSS THE NORTHERN PLAINS. DRY
CONDITIONS WILL PERSIST INTO SATURDAY AFTERNOON WITH MODERATING
TEMPERATURES EXPECTED. HIGHS THIS AFTERNOON WILL REACH INTO THE LOW TO
MID 70S.

&&

.UPDATE...
ISSUED AT 145 PM EDT FRI SEP 19 2014

BROAD LOW LEVEL ANTICYCLONE WILL PROVIDE SUNNY/MOSTLY SUNNY SKIES
THROUGH THE REMAINDER OF THE AFTERNOON WITH JUST SOME LOW COVERAGE
CIRRUS WORKING ACROSS THE AREA. NAM SHORT TERM SOUNDINGS INDICATE
MIXING UP TO 900-875 HPA THIS AFTERNOON...WHICH WOULD SUPPORT
GOING HIGHS IN THE LOWER TO MID 70S. ALL OTHER FORECAST ELEMENTS
ARE IN GOOD SHAPE AND NO FIRST PERIOD ZFP UPDATE IS CURRENTLY
ANTICIPATED.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EDT FRI SEP 19 2014

SFC RIDGE CNTRD OVR SERN ONTARIO WILL GIVE WAY TO PROGRESSIVE SW
TROUGH AND ATTENDANT FNTL SYS BY SAT. INCREASING LL WAA ESP LATE
THIS AFTN WILL GIVE A BOOST TO TEMPS ESP WRN/SRN ZONES VS YDA. MUCH
WARMER ESP WRN HALF IN PROXIMITY TO STGR SWRLY GRADIENT FLW AND
LIKELY ENCROACHMENT OF HIGH CLD SHIELD. OTRWS DRY AS WRN BOUND OF LL
ANTICYCLONE SLW TO MOISTEN ALG W/VEERED LL WRLY FLW SUGGESTING
GENERAL WK SUBSIDENT FLW WILL PERSIST INTO SAT AM.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EDT FRI SEP 19 2014

POTENTIALLY ACTIVE SAT AFTN/EVE PERIOD IN STORE FOR AT LEAST NW
PARTS OF THE AREA AS INCREASINGLY FAVORABLE LOOKING DYNAMICS APPEAR
TO BE COMING INTO PLAY.

TOUGH FORECAST IN TERMS OF HOW TO HANDLE CHANCES FOR SHOWERS/STORMS
AS MODELS HAVE ALL BACKED OFF ON PRECIP CHANCES (NOW GENERALLY CHC
TO A FEW SPOTS SHOWING LIKELY) SAT AFTN/EVE AS SPEED AND DEPTH OF
MSTR RETURN REMAINS IN QUESTION. WITH LOW TO MID 60 DEWPTS NOT THAT
FAR AWAY GIVEN INCREASING FLOW WHICH WILL SETUP OVER THE NEXT 24
HOURS...IT IS PLAUSIBLE FOR SIMILAR VALUES TO ADVECT IN RIGHT AHEAD
OF THE COLD FRONT DURING PEAK HEATING. 0-3 KM SHEAR ON BUFKIT
SOUNDINGS ALL POINT TOWARDS ANYWHERE FROM 40 TO 50 KTS OF MAINLY
UNIDIRECTIONAL SHEAR. THIS WOULD SET THE STAGE FOR A RISK OF
STG-SEVERE STORMS IF TIMING AND MSTR ALIGN JUST RIGHT. MODELS VARY
GREATLY ON THESE POINTS RANGING FROM A FEW HUNDRED J/KG OF SURFACE
BASED CAPE TO PUSHING 2000 J/KG. SPC DAY 2 OUTLOOK HAS PLACED THE NW
QUARTER OR SO OF THE AREA IN A SLIGHT RISK FOR DAMAGING WINDS. WHILE
WE CAN`T DISAGREE...THIS WILL BE HIGHLY CONDITIONAL ON TEMPS
CLIMBING INTO THE UPPER 70S TO LOWER 80S AND DEWPTS INTO AT LEAST
THE LOWER 60S. RISK DIMINISHES RAPIDLY WITH SE PROGRESSION ASSUMING
NO ORGANIZED COLD POOL WERE TO ESTABLISH. CHANCES SAT AM LOOKING
RATHER POOR (IF THIS DID UNFOLD THEN CHANCE FOR SEVERE WOULD BE
DIMINISHED GIVEN POSSIBLE CONVECTIVE DEBRIS). HAVE CONFINED SLGT CHC
POPS TO FAR NW. OTHERWISE HAVE LEFT SAT AFTN INTO SAT NIGHT ALONE
DESPITE ABOVE MENTIONED ISSUES WITH GUIDANCE.

SOME LINGERING SHOWERS MAY EXIST IN THE SE SUNDAY MORNING...BUT
SHOULD QUICKLY DEPART WITH SEASONABLE AFTERNOON HIGHS IN THE LOWER
TO MIDDLE 70S. MAIN SHOT OF COLDER AIR WILL ARRIVE SUNDAY NIGHT WITH
SFC HIGH PRESSURE SETTLING OVER THE LOWER GREAT LAKES INTO NEXT
WEEK. COULD BE A STRAY SHOWER WITH THE TROUGH PASSAGE BUT OVERALL
LIFT AND REMAINING MSTR LOOKS RATHER BLEAK.

TEMPERATURES WILL BEGIN TO MODERATE BACK TOWARDS NORMAL LEVELS BY
MID WEEK AS THE HIGH SHIFTS EAST OF THE AREA AND THEN SETTLES IN
OVER THE EASTERN STATES. THIS SHOULD ALLOW FOR A QUIET
PERIOD...LIKELY EXTENDING INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 145 PM EDT FRI SEP 19 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE BULK OF THIS FORECAST
PERIOD. LARGE LOW LEVEL ANTICYCLONE ACROSS EASTERN CONUS WILL
CONTINUE TO BE THE PRIMARY FEATURE CONTROLLING WEATHER ACROSS
NORTHERN INDIANA THROUGH TONIGHT. SOUTHEAST WINDS ON THE WESTERN
PERIPHERY OF THIS HIGH PRESSURE WILL CONTINUE THROUGH THE
PERIOD...VEERING MORE SOUTHERLY TONIGHT AS NEXT TROUGH OF LOW
PRESSURE TRACKS INTO THE UPPER MIDWEST. STRONG LOW LEVEL THETAE
ADVECTION PRECEDING COLD FRONT IN ASSOCIATION WITH NEXT MID/UPPER
LEVEL SYSTEM WILL WORK ACROSS NORTHERN INDIANA SATURDAY MORNING.
SOME SHOWERS MAY DEVELOP IN ASSOCIATION WITH THIS STRONG LOW LEVEL
THETAE ADVECTION...BUT GREATER CHANCES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO HOLD OFF UNTIL AFTER 18Z AS
MID/UPPER LEVEL TROUGH AXIS APPROACHES WESTERN GREAT LAKES REGION.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
     SATURDAY FOR LMZ043-046.

&&

$$

UPDATE...MARSILI
SYNOPSIS...T
SHORT TERM...T
LONG TERM...FISHER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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000
FXUS63 KIWX 191751
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
151 PM EDT FRI SEP 19 2014

.SYNOPSIS...
ISSUED AT 355 AM EDT FRI SEP 19 2014

HIGH PRESSURE WILL BEGIN TO RETREAT EASTWARD IN ADVANCE OF A
DEVELOPING LOW PRESSURE SYSTEM ACROSS THE NORTHERN PLAINS. DRY
CONDITIONS WILL PERSIST INTO SATURDAY AFTERNOON WITH MODERATING
TEMPERATURES EXPECTED. HIGHS THIS AFTERNOON WILL REACH INTO THE LOW TO
MID 70S.

&&

.UPDATE...
ISSUED AT 145 PM EDT FRI SEP 19 2014

BROAD LOW LEVEL ANTICYCLONE WILL PROVIDE SUNNY/MOSTLY SUNNY SKIES
THROUGH THE REMAINDER OF THE AFTERNOON WITH JUST SOME LOW COVERAGE
CIRRUS WORKING ACROSS THE AREA. NAM SHORT TERM SOUNDINGS INDICATE
MIXING UP TO 900-875 HPA THIS AFTERNOON...WHICH WOULD SUPPORT
GOING HIGHS IN THE LOWER TO MID 70S. ALL OTHER FORECAST ELEMENTS
ARE IN GOOD SHAPE AND NO FIRST PERIOD ZFP UPDATE IS CURRENTLY
ANTICIPATED.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EDT FRI SEP 19 2014

SFC RIDGE CNTRD OVR SERN ONTARIO WILL GIVE WAY TO PROGRESSIVE SW
TROUGH AND ATTENDANT FNTL SYS BY SAT. INCREASING LL WAA ESP LATE
THIS AFTN WILL GIVE A BOOST TO TEMPS ESP WRN/SRN ZONES VS YDA. MUCH
WARMER ESP WRN HALF IN PROXIMITY TO STGR SWRLY GRADIENT FLW AND
LIKELY ENCROACHMENT OF HIGH CLD SHIELD. OTRWS DRY AS WRN BOUND OF LL
ANTICYCLONE SLW TO MOISTEN ALG W/VEERED LL WRLY FLW SUGGESTING
GENERAL WK SUBSIDENT FLW WILL PERSIST INTO SAT AM.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EDT FRI SEP 19 2014

POTENTIALLY ACTIVE SAT AFTN/EVE PERIOD IN STORE FOR AT LEAST NW
PARTS OF THE AREA AS INCREASINGLY FAVORABLE LOOKING DYNAMICS APPEAR
TO BE COMING INTO PLAY.

TOUGH FORECAST IN TERMS OF HOW TO HANDLE CHANCES FOR SHOWERS/STORMS
AS MODELS HAVE ALL BACKED OFF ON PRECIP CHANCES (NOW GENERALLY CHC
TO A FEW SPOTS SHOWING LIKELY) SAT AFTN/EVE AS SPEED AND DEPTH OF
MSTR RETURN REMAINS IN QUESTION. WITH LOW TO MID 60 DEWPTS NOT THAT
FAR AWAY GIVEN INCREASING FLOW WHICH WILL SETUP OVER THE NEXT 24
HOURS...IT IS PLAUSIBLE FOR SIMILAR VALUES TO ADVECT IN RIGHT AHEAD
OF THE COLD FRONT DURING PEAK HEATING. 0-3 KM SHEAR ON BUFKIT
SOUNDINGS ALL POINT TOWARDS ANYWHERE FROM 40 TO 50 KTS OF MAINLY
UNIDIRECTIONAL SHEAR. THIS WOULD SET THE STAGE FOR A RISK OF
STG-SEVERE STORMS IF TIMING AND MSTR ALIGN JUST RIGHT. MODELS VARY
GREATLY ON THESE POINTS RANGING FROM A FEW HUNDRED J/KG OF SURFACE
BASED CAPE TO PUSHING 2000 J/KG. SPC DAY 2 OUTLOOK HAS PLACED THE NW
QUARTER OR SO OF THE AREA IN A SLIGHT RISK FOR DAMAGING WINDS. WHILE
WE CAN`T DISAGREE...THIS WILL BE HIGHLY CONDITIONAL ON TEMPS
CLIMBING INTO THE UPPER 70S TO LOWER 80S AND DEWPTS INTO AT LEAST
THE LOWER 60S. RISK DIMINISHES RAPIDLY WITH SE PROGRESSION ASSUMING
NO ORGANIZED COLD POOL WERE TO ESTABLISH. CHANCES SAT AM LOOKING
RATHER POOR (IF THIS DID UNFOLD THEN CHANCE FOR SEVERE WOULD BE
DIMINISHED GIVEN POSSIBLE CONVECTIVE DEBRIS). HAVE CONFINED SLGT CHC
POPS TO FAR NW. OTHERWISE HAVE LEFT SAT AFTN INTO SAT NIGHT ALONE
DESPITE ABOVE MENTIONED ISSUES WITH GUIDANCE.

SOME LINGERING SHOWERS MAY EXIST IN THE SE SUNDAY MORNING...BUT
SHOULD QUICKLY DEPART WITH SEASONABLE AFTERNOON HIGHS IN THE LOWER
TO MIDDLE 70S. MAIN SHOT OF COLDER AIR WILL ARRIVE SUNDAY NIGHT WITH
SFC HIGH PRESSURE SETTLING OVER THE LOWER GREAT LAKES INTO NEXT
WEEK. COULD BE A STRAY SHOWER WITH THE TROUGH PASSAGE BUT OVERALL
LIFT AND REMAINING MSTR LOOKS RATHER BLEAK.

TEMPERATURES WILL BEGIN TO MODERATE BACK TOWARDS NORMAL LEVELS BY
MID WEEK AS THE HIGH SHIFTS EAST OF THE AREA AND THEN SETTLES IN
OVER THE EASTERN STATES. THIS SHOULD ALLOW FOR A QUIET
PERIOD...LIKELY EXTENDING INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 145 PM EDT FRI SEP 19 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE BULK OF THIS FORECAST
PERIOD. LARGE LOW LEVEL ANTICYCLONE ACROSS EASTERN CONUS WILL
CONTINUE TO BE THE PRIMARY FEATURE CONTROLLING WEATHER ACROSS
NORTHERN INDIANA THROUGH TONIGHT. SOUTHEAST WINDS ON THE WESTERN
PERIPHERY OF THIS HIGH PRESSURE WILL CONTINUE THROUGH THE
PERIOD...VEERING MORE SOUTHERLY TONIGHT AS NEXT TROUGH OF LOW
PRESSURE TRACKS INTO THE UPPER MIDWEST. STRONG LOW LEVEL THETAE
ADVECTION PRECEDING COLD FRONT IN ASSOCIATION WITH NEXT MID/UPPER
LEVEL SYSTEM WILL WORK ACROSS NORTHERN INDIANA SATURDAY MORNING.
SOME SHOWERS MAY DEVELOP IN ASSOCIATION WITH THIS STRONG LOW LEVEL
THETAE ADVECTION...BUT GREATER CHANCES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO HOLD OFF UNTIL AFTER 18Z AS
MID/UPPER LEVEL TROUGH AXIS APPROACHES WESTERN GREAT LAKES REGION.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
     SATURDAY FOR LMZ043-046.

&&

$$

UPDATE...MARSILI
SYNOPSIS...T
SHORT TERM...T
LONG TERM...FISHER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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000
FXUS63 KIWX 190755
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
355 AM EDT FRI SEP 19 2014

.SYNOPSIS...
ISSUED AT 355 AM EDT FRI SEP 19 2014

HIGH PRESSURE WILL BEGIN TO RETREAT EASTWARD IN ADVANCE OF A
DEVELOPING LOW PRESSURE SYSTEM ACROSS THE NORTHERN PLAINS. DRY
CONDITIONS WILL PERSIST INTO SATURDAY AFTERNOON WITH MODERATING
TEMPERATURES EXPECTED. HIGHS THIS AFTERNOON WILL REACH INTO THE LOW TO
MID 70S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EDT FRI SEP 19 2014

SFC RIDGE CNTRD OVR SERN ONTARIO WILL GIVE WAY TO PROGRESSIVE SW
TROUGH AND ATTENDANT FNTL SYS BY SAT. INCREASING LL WAA ESP LATE
THIS AFTN WILL GIVE A BOOST TO TEMPS ESP WRN/SRN ZONES VS YDA. MUCH
WARMER ESP WRN HALF IN PROXIMITY TO STGR SWRLY GRADIENT FLW AND
LIKELY ENCROACHMENT OF HIGH CLD SHIELD. OTRWS DRY AS WRN BOUND OF LL
ANTICYCLONE SLW TO MOISTEN ALG W/VEERED LL WRLY FLW SUGGESTING
GENERAL WK SUBSIDENT FLW WILL PERSIST INTO SAT AM.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EDT FRI SEP 19 2014

POTENTIALLY ACTIVE SAT AFTN/EVE PERIOD IN STORE FOR AT LEAST NW
PARTS OF THE AREA AS INCREASINGLY FAVORABLE LOOKING DYNAMICS APPEAR
TO BE COMING INTO PLAY.

TOUGH FORECAST IN TERMS OF HOW TO HANDLE CHANCES FOR SHOWERS/STORMS
AS MODELS HAVE ALL BACKED OFF ON PRECIP CHANCES (NOW GENERALLY CHC
TO A FEW SPOTS SHOWING LIKELY) SAT AFTN/EVE AS SPEED AND DEPTH OF
MSTR RETURN REMAINS IN QUESTION. WITH LOW TO MID 60 DEWPTS NOT THAT
FAR AWAY GIVEN INCREASING FLOW WHICH WILL SETUP OVER THE NEXT 24
HOURS...IT IS PLAUSIBLE FOR SIMILAR VALUES TO ADVECT IN RIGHT AHEAD
OF THE COLD FRONT DURING PEAK HEATING. 0-3 KM SHEAR ON BUFKIT
SOUNDINGS ALL POINT TOWARDS ANYWHERE FROM 40 TO 50 KTS OF MAINLY
UNIDIRECTIONAL SHEAR. THIS WOULD SET THE STAGE FOR A RISK OF
STG-SEVERE STORMS IF TIMING AND MSTR ALIGN JUST RIGHT. MODELS VARY
GREATLY ON THESE POINTS RANGING FROM A FEW HUNDRED J/KG OF SURFACE
BASED CAPE TO PUSHING 2000 J/KG. SPC DAY 2 OUTLOOK HAS PLACED THE NW
QUARTER OR SO OF THE AREA IN A SLIGHT RISK FOR DAMAGING WINDS. WHILE
WE CAN`T DISAGREE...THIS WILL BE HIGHLY CONDITIONAL ON TEMPS
CLIMBING INTO THE UPPER 70S TO LOWER 80S AND DEWPTS INTO AT LEAST
THE LOWER 60S. RISK DIMINISHES RAPIDLY WITH SE PROGRESSION ASSUMING
NO ORGANIZED COLD POOL WERE TO ESTABLISH. CHANCES SAT AM LOOKING
RATHER POOR (IF THIS DID UNFOLD THEN CHANCE FOR SEVERE WOULD BE
DIMINISHED GIVEN POSSIBLE CONVECTIVE DEBRIS). HAVE CONFINED SLGT CHC
POPS TO FAR NW. OTHERWISE HAVE LEFT SAT AFTN INTO SAT NIGHT ALONE
DESPITE ABOVE MENTIONED ISSUES WITH GUIDANCE.

SOME LINGERING SHOWERS MAY EXIST IN THE SE SUNDAY MORNING...BUT
SHOULD QUICKLY DEPART WITH SEASONABLE AFTERNOON HIGHS IN THE LOWER
TO MIDDLE 70S. MAIN SHOT OF COLDER AIR WILL ARRIVE SUNDAY NIGHT WITH
SFC HIGH PRESSURE SETTLING OVER THE LOWER GREAT LAKES INTO NEXT
WEEK. COULD BE A STRAY SHOWER WITH THE TROUGH PASSAGE BUT OVERALL
LIFT AND REMAINING MSTR LOOKS RATHER BLEAK.

TEMPERATURES WILL BEGIN TO MODERATE BACK TOWARDS NORMAL LEVELS BY
MID WEEK AS THE HIGH SHIFTS EAST OF THE AREA AND THEN SETTLES IN
OVER THE EASTERN STATES. THIS SHOULD ALLOW FOR A QUIET
PERIOD...LIKELY EXTENDING INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 352 AM EDT FRI SEP 19 2014


VFR CONDS THROUGH THE PD. HWVR EWD RETREAT OF STOUT SFC ANTICYCLONE
IN RESPONSE TO DVLPG NRN PLAINS SFC FNTL WAVE. XPC SFC GRADIENT TO
RAMP THIS AFTN VCNTY KSBN W/SFC GUSTS TO 15KTS.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
     SATURDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...T
SHORT TERM...T
LONG TERM...FISHER
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 182324
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
724 PM EDT THU SEP 18 2014

.SYNOPSIS...
ISSUED AT 325 PM EDT THU SEP 18 2014

HIGH PRESSURE WILL REMAIN ENTRENCHED ACROSS THE OHIO VALLEY
THROUGH FRIDAY WITH DRY CONDITIONS AND MODERATING TEMPERATURES.
LOWS TONIGHT WILL DROP INTO THE 40S...AND RECOVER INTO THE LOW TO
MID 70S ON FRIDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 325 PM EDT THU SEP 18 2014

HEIGHT RISES ALOFT WITH SFC RIDGE AXIS HANGING BACK FROM A
STRENGTHENING SE CANADA SFC HIGH WILL ENSURE MORE OF THE SAME
(DRY/FAIR WX) THIS PERIOD. MAINLY CLEAR SKIES AND LIGHT EASTERLY
GRADIENT WINDS WILL SUPPORT ANOTHER COOL NIGHT WITH COOLER MOS
GUIDANCE FAVORED. ALSO...LOWS FALLING NEAR OR JUST BELOW XOVER
VALUES MAY BE ENOUGH TO HELP GENERATE SOME PATCHY/SHALLOW GROUND
FOG TOWARD DAYBREAK...WITH LOW CHANCES FOR LOW STRATUS TO FILL
INTO FAR NORTHEASTERN ZONES GIVEN LIGHT FLOW OFF OF LAKE ERIE.
OTHERWISE...GRADUAL WARMING TREND CONTINUES INTO TOMORROW WITH
BRIEF RELAXATION OF EASTERN CONUS TROUGH.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 PM EDT THU SEP 18 2014

FOCUS STILL ON MAIN COLD FRONT AND RAIN CHANCES SATURDAY AFTERNOON
INTO EARLY SUNDAY MORNING. LATEST 12Z GUIDANCE HAS CONTINUED TREND
OF SPEEDING UP ONSET OF PCPN WITH MODELS IN GOOD AGREEMENT ON
PRECIPITATION ACROSS NORTHERN HALF OF AREA BY LATE SATURDAY
AFTERNOON.

HIGH PRESSURE WILL BE SLIDING EAST FRIDAY NIGHT WITH RETURN FLOW
DEVELOPING. INITIAL THETA E SURGE WILL APPROACH AND MOVE INTO THE
NORTHWEST EARLY SATURDAY MORNING. LOW LEVEL JET OF 30 TO 40 KNOT
BEING SHOWN IN MODELS UPSTREAM ACROSS WI AND IMPINGING ON THIS
HIGHER MOISTURE. THIS ALLOWS SHOWERS AND FEW THUNDERSTORMS TO
DEVELOP OVERNIGHT IN THAT AREA. MODELS ARE TRYING TO BRING THIS
DECAYING PCPN INTO THE NORTHWEST SATURDAY MORNING WELL AHEAD OF MAIN
FRONT AND HEIGHT FALLS. GIVEN THE MODEL SIGNAL LAST SEVERAL RUNS
HAVE ADDED A VERY LOW POP TO THIS AREA SATURDAY MORNING. OTHERWISE
MODELS HAVE SPED UP APPROACH OF MAIN SHORT WAVE AND ARE SHOWING
AFTERNOON CONVECTIVE DEVELOPMENT IN THE NORTH. MODEL SOUNDINGS STILL
SHOW A GOOD LOW LEVEL INVERSION BUT INSTABILITY ALOFT IS LIKELY WHAT
MODELS ARE KEYING ON. THIS INVERSION AND ADDED CLOUD COVER IN
AFTERNOON TO ALSO LIMIT MIXING HEIGHTS MAKING TEMPERATURE FORECAST
DIFFICULT. WITH MODEL AGREEMENT ON MID AFTERNOON PCPN DEVELOPMENT
NOW HAVE INCREASED POPS CONSIDERABLY AFTER 18Z AND ESPECIALLY AFTER
21Z FAR NORTHWEST. ALSO BLENDED LATEST TEMP GUIDANCE BUT KEPT HIGHS
IN LOWER 80S FAR SOUTH WHERE BEST MIXING AND SUN POTENTIAL EXISTS.

FRONTAL BOUNDARY TO SWEEP THROUGH SATURDAY NIGHT. INSTABILITY
REMAINS LOW BUT PWATS ON BOTH NAM12 AND GFS40 AROUND 1.8 INCHES
WHICH IS ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL. CONVECTION
POSSIBLE WITH MARGINAL INSTABILITY BUT GOOD SHEAR SO KEPT TSRA IN
FORECAST. LOCALLY HEAVY RAIN ONCE AGAIN POSSIBLE BUT PROGRESSIVE
NATURE TO FRONT SHOULD KEEP FLOODING THREAT MINIMAL. QPF IN THE HALF
TO ONE INCH RANGE LOOKS LIKELY ESPECIALLY FOR CENTRAL AND NORTHERN
AREAS. STILL THINK SOME OF THIS MOISTURE IS MID TROPOSPHERIC
CONTRIBUTION FROM ODILE REMNANTS DESPITE MAIN CIRCULATION REMAINING
WELL SOUTHWEST OF AREA.

CLEARING EXPECTED SUNDAY IN WAKE OF FRONT WITH SEASONABLE
TEMPERATURES. SECONDARY SHORT WAVE AND FRONT WILL BRING COOLER
TEMPERATURES FOR MONDAY AND TUESDAY WITH HIGHS BACK INTO THE 60S.
STILL AN EYE ON LAKE EFFECT POTENTIAL AND SOME LIGHT SHOWER
POTENTIAL WITH SECONDARY SHORT WAVE BUT NOT ENOUGH MODEL SIGNAL IN
MOISTURE PROFILES TO WARRANT ADDING POPS AT THIS TIME. HIGH PRESSURE
THEN MOVES IN FOR REMAINDER OF LONG TERM WITH MODERATING
TEMPERATURES BACK INTO 70S AND DRY WEATHER.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 723 PM EDT THU SEP 18 2014

FEW CU OVER THE AREA SHOULD GRDLY DISSIPATE THIS EVE. WK LOW LEVEL
MOISTURE ADVECTION OVERNIGHT COMBINED WITH RADIATIONAL COOLING MAY
RESULT IN MVFR VSBY RESTRICTIONS TOWARD DAYBREAK... OTRWS VFR
CONDITIONS EXPECTED THROUGH THE PERIOD WITH WARMER TEMPS ALOFT FRI
RESULTING IN LITTLE OR NO CU.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...MCD/STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...JT


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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000
FXUS63 KIWX 181926
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
326 PM EDT THU SEP 18 2014

.SYNOPSIS...
ISSUED AT 325 PM EDT THU SEP 18 2014

HIGH PRESSURE WILL REMAIN ENTRENCHED ACROSS THE OHIO VALLEY
THROUGH FRIDAY WITH DRY CONDITIONS AND MODERATING TEMPERATURES.
LOWS TONIGHT WILL DROP INTO THE 40S...AND RECOVER INTO THE LOW TO
MID 70S ON FRIDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 325 PM EDT THU SEP 18 2014

HEIGHT RISES ALOFT WITH SFC RIDGE AXIS HANGING BACK FROM A
STRENGTHENING SE CANADA SFC HIGH WILL ENSURE MORE OF THE SAME
(DRY/FAIR WX) THIS PERIOD. MAINLY CLEAR SKIES AND LIGHT EASTERLY
GRADIENT WINDS WILL SUPPORT ANOTHER COOL NIGHT WITH COOLER MOS
GUIDANCE FAVORED. ALSO...LOWS FALLING NEAR OR JUST BELOW XOVER
VALUES MAY BE ENOUGH TO HELP GENERATE SOME PATCHY/SHALLOW GROUND
FOG TOWARD DAYBREAK...WITH LOW CHANCES FOR LOW STRATUS TO FILL
INTO FAR NORTHEASTERN ZONES GIVEN LIGHT FLOW OFF OF LAKE ERIE.
OTHERWISE...GRADUAL WARMING TREND CONTINUES INTO TOMORROW WITH
BRIEF RELAXATION OF EASTERN CONUS TROUGH.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 PM EDT THU SEP 18 2014

FOCUS STILL ON MAIN COLD FRONT AND RAIN CHANCES SATURDAY AFTERNOON
INTO EARLY SUNDAY MORNING. LATEST 12Z GUIDANCE HAS CONTINUED TREND
OF SPEEDING UP ONSET OF PCPN WITH MODELS IN GOOD AGREEMENT ON
PRECIPITATION ACROSS NORTHERN HALF OF AREA BY LATE SATURDAY
AFTERNOON.

HIGH PRESSURE WILL BE SLIDING EAST FRIDAY NIGHT WITH RETURN FLOW
DEVELOPING. INITIAL THETA E SURGE WILL APPROACH AND MOVE INTO THE
NORTHWEST EARLY SATURDAY MORNING. LOW LEVEL JET OF 30 TO 40 KNOT
BEING SHOWN IN MODELS UPSTREAM ACROSS WI AND IMPINGING ON THIS
HIGHER MOISTURE. THIS ALLOWS SHOWERS AND FEW THUNDERSTORMS TO
DEVELOP OVERNIGHT IN THAT AREA. MODELS ARE TRYING TO BRING THIS
DECAYING PCPN INTO THE NORTHWEST SATURDAY MORNING WELL AHEAD OF MAIN
FRONT AND HEIGHT FALLS. GIVEN THE MODEL SIGNAL LAST SEVERAL RUNS
HAVE ADDED A VERY LOW POP TO THIS AREA SATURDAY MORNING. OTHERWISE
MODELS HAVE SPED UP APPROACH OF MAIN SHORT WAVE AND ARE SHOWING
AFTERNOON CONVECTIVE DEVELOPMENT IN THE NORTH. MODEL SOUNDINGS STILL
SHOW A GOOD LOW LEVEL INVERSION BUT INSTABILITY ALOFT IS LIKELY WHAT
MODELS ARE KEYING ON. THIS INVERSION AND ADDED CLOUD COVER IN
AFTERNOON TO ALSO LIMIT MIXING HEIGHTS MAKING TEMPERATURE FORECAST
DIFFICULT. WITH MODEL AGREEMENT ON MID AFTERNOON PCPN DEVELOPMENT
NOW HAVE INCREASED POPS CONSIDERABLY AFTER 18Z AND ESPECIALLY AFTER
21Z FAR NORTHWEST. ALSO BLENDED LATEST TEMP GUIDANCE BUT KEPT HIGHS
IN LOWER 80S FAR SOUTH WHERE BEST MIXING AND SUN POTENTIAL EXISTS.

FRONTAL BOUNDARY TO SWEEP THROUGH SATURDAY NIGHT. INSTABILITY
REMAINS LOW BUT PWATS ON BOTH NAM12 AND GFS40 AROUND 1.8 INCHES
WHICH IS ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL. CONVECTION
POSSIBLE WITH MARGINAL INSTABILITY BUT GOOD SHEAR SO KEPT TSRA IN
FORECAST. LOCALLY HEAVY RAIN ONCE AGAIN POSSIBLE BUT PROGRESSIVE
NATURE TO FRONT SHOULD KEEP FLOODING THREAT MINIMAL. QPF IN THE HALF
TO ONE INCH RANGE LOOKS LIKELY ESPECIALLY FOR CENTRAL AND NORTHERN
AREAS. STILL THINK SOME OF THIS MOISTURE IS MID TROPOSPHERIC
CONTRIBUTION FROM ODILE REMNANTS DESPITE MAIN CIRCULATION REMAINING
WELL SOUTHWEST OF AREA.

CLEARING EXPECTED SUNDAY IN WAKE OF FRONT WITH SEASONABLE
TEMPERATURES. SECONDARY SHORT WAVE AND FRONT WILL BRING COOLER
TEMPERATURES FOR MONDAY AND TUESDAY WITH HIGHS BACK INTO THE 60S.
STILL AN EYE ON LAKE EFFECT POTENTIAL AND SOME LIGHT SHOWER
POTENTIAL WITH SECONDARY SHORT WAVE BUT NOT ENOUGH MODEL SIGNAL IN
MOISTURE PROFILES TO WARRANT ADDING POPS AT THIS TIME. HIGH PRESSURE
THEN MOVES IN FOR REMAINDER OF LONG TERM WITH MODERATING
TEMPERATURES BACK INTO 70S AND DRY WEATHER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 102 PM EDT THU SEP 18 2014

SFC RIDGING IN SUBSIDENT/DRY NORTHWEST FLOW SHOULD RESULT IN A
CONTINUATION OF VFR CONDITIONS/MAINLY CLEAR SKIES THROUGH THE TAF
CYCLE. COULD SEE SOME PATCHY FOG/STRATUS DEVELOPMENT TOWARD 9-12Z
FRIDAY...BUT COVERAGE/CONFIDENCE REMAINS TOO LOW FOR INCLUSION
THIS ISSUANCE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...MCD/STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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000
FXUS63 KIWX 181926
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
326 PM EDT THU SEP 18 2014

.SYNOPSIS...
ISSUED AT 325 PM EDT THU SEP 18 2014

HIGH PRESSURE WILL REMAIN ENTRENCHED ACROSS THE OHIO VALLEY
THROUGH FRIDAY WITH DRY CONDITIONS AND MODERATING TEMPERATURES.
LOWS TONIGHT WILL DROP INTO THE 40S...AND RECOVER INTO THE LOW TO
MID 70S ON FRIDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 325 PM EDT THU SEP 18 2014

HEIGHT RISES ALOFT WITH SFC RIDGE AXIS HANGING BACK FROM A
STRENGTHENING SE CANADA SFC HIGH WILL ENSURE MORE OF THE SAME
(DRY/FAIR WX) THIS PERIOD. MAINLY CLEAR SKIES AND LIGHT EASTERLY
GRADIENT WINDS WILL SUPPORT ANOTHER COOL NIGHT WITH COOLER MOS
GUIDANCE FAVORED. ALSO...LOWS FALLING NEAR OR JUST BELOW XOVER
VALUES MAY BE ENOUGH TO HELP GENERATE SOME PATCHY/SHALLOW GROUND
FOG TOWARD DAYBREAK...WITH LOW CHANCES FOR LOW STRATUS TO FILL
INTO FAR NORTHEASTERN ZONES GIVEN LIGHT FLOW OFF OF LAKE ERIE.
OTHERWISE...GRADUAL WARMING TREND CONTINUES INTO TOMORROW WITH
BRIEF RELAXATION OF EASTERN CONUS TROUGH.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 PM EDT THU SEP 18 2014

FOCUS STILL ON MAIN COLD FRONT AND RAIN CHANCES SATURDAY AFTERNOON
INTO EARLY SUNDAY MORNING. LATEST 12Z GUIDANCE HAS CONTINUED TREND
OF SPEEDING UP ONSET OF PCPN WITH MODELS IN GOOD AGREEMENT ON
PRECIPITATION ACROSS NORTHERN HALF OF AREA BY LATE SATURDAY
AFTERNOON.

HIGH PRESSURE WILL BE SLIDING EAST FRIDAY NIGHT WITH RETURN FLOW
DEVELOPING. INITIAL THETA E SURGE WILL APPROACH AND MOVE INTO THE
NORTHWEST EARLY SATURDAY MORNING. LOW LEVEL JET OF 30 TO 40 KNOT
BEING SHOWN IN MODELS UPSTREAM ACROSS WI AND IMPINGING ON THIS
HIGHER MOISTURE. THIS ALLOWS SHOWERS AND FEW THUNDERSTORMS TO
DEVELOP OVERNIGHT IN THAT AREA. MODELS ARE TRYING TO BRING THIS
DECAYING PCPN INTO THE NORTHWEST SATURDAY MORNING WELL AHEAD OF MAIN
FRONT AND HEIGHT FALLS. GIVEN THE MODEL SIGNAL LAST SEVERAL RUNS
HAVE ADDED A VERY LOW POP TO THIS AREA SATURDAY MORNING. OTHERWISE
MODELS HAVE SPED UP APPROACH OF MAIN SHORT WAVE AND ARE SHOWING
AFTERNOON CONVECTIVE DEVELOPMENT IN THE NORTH. MODEL SOUNDINGS STILL
SHOW A GOOD LOW LEVEL INVERSION BUT INSTABILITY ALOFT IS LIKELY WHAT
MODELS ARE KEYING ON. THIS INVERSION AND ADDED CLOUD COVER IN
AFTERNOON TO ALSO LIMIT MIXING HEIGHTS MAKING TEMPERATURE FORECAST
DIFFICULT. WITH MODEL AGREEMENT ON MID AFTERNOON PCPN DEVELOPMENT
NOW HAVE INCREASED POPS CONSIDERABLY AFTER 18Z AND ESPECIALLY AFTER
21Z FAR NORTHWEST. ALSO BLENDED LATEST TEMP GUIDANCE BUT KEPT HIGHS
IN LOWER 80S FAR SOUTH WHERE BEST MIXING AND SUN POTENTIAL EXISTS.

FRONTAL BOUNDARY TO SWEEP THROUGH SATURDAY NIGHT. INSTABILITY
REMAINS LOW BUT PWATS ON BOTH NAM12 AND GFS40 AROUND 1.8 INCHES
WHICH IS ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL. CONVECTION
POSSIBLE WITH MARGINAL INSTABILITY BUT GOOD SHEAR SO KEPT TSRA IN
FORECAST. LOCALLY HEAVY RAIN ONCE AGAIN POSSIBLE BUT PROGRESSIVE
NATURE TO FRONT SHOULD KEEP FLOODING THREAT MINIMAL. QPF IN THE HALF
TO ONE INCH RANGE LOOKS LIKELY ESPECIALLY FOR CENTRAL AND NORTHERN
AREAS. STILL THINK SOME OF THIS MOISTURE IS MID TROPOSPHERIC
CONTRIBUTION FROM ODILE REMNANTS DESPITE MAIN CIRCULATION REMAINING
WELL SOUTHWEST OF AREA.

CLEARING EXPECTED SUNDAY IN WAKE OF FRONT WITH SEASONABLE
TEMPERATURES. SECONDARY SHORT WAVE AND FRONT WILL BRING COOLER
TEMPERATURES FOR MONDAY AND TUESDAY WITH HIGHS BACK INTO THE 60S.
STILL AN EYE ON LAKE EFFECT POTENTIAL AND SOME LIGHT SHOWER
POTENTIAL WITH SECONDARY SHORT WAVE BUT NOT ENOUGH MODEL SIGNAL IN
MOISTURE PROFILES TO WARRANT ADDING POPS AT THIS TIME. HIGH PRESSURE
THEN MOVES IN FOR REMAINDER OF LONG TERM WITH MODERATING
TEMPERATURES BACK INTO 70S AND DRY WEATHER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 102 PM EDT THU SEP 18 2014

SFC RIDGING IN SUBSIDENT/DRY NORTHWEST FLOW SHOULD RESULT IN A
CONTINUATION OF VFR CONDITIONS/MAINLY CLEAR SKIES THROUGH THE TAF
CYCLE. COULD SEE SOME PATCHY FOG/STRATUS DEVELOPMENT TOWARD 9-12Z
FRIDAY...BUT COVERAGE/CONFIDENCE REMAINS TOO LOW FOR INCLUSION
THIS ISSUANCE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...MCD/STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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000
FXUS63 KIWX 181702
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
102 PM EDT THU SEP 18 2014

.SYNOPSIS...
ISSUED AT 356 AM EDT THU SEP 18 2014

HIGH PRESSURE WILL REMAIN ENTRENCHED ACROSS THE OHIO VALLEY
THROUGH FRIDAY WITH DRY CONDITIONS AND MODERATING TEMPERATURES.
HIGHS THIS AFTERNOON WILL PEAK OUT IN THE UPPER 60S TO LOWER 70S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM EDT THU SEP 18 2014

RENEWED SFC RIDGING BLDG SEWD OUT OF CANADA IN BEHIND VIGOROUS SW
TROUGH AMPLIFYING EWD ACRS SE CANADA WILL RESULT IN A CONTN OF
STELLAR LT SUMMER CONDS THIS PD. HIGH THIS AFTN SHLD AGAIN NOTCH A
DEGREE OR TWO WARMER THAN YDA FOLLOWED BY SEASONABLY COOL TEMPS
OVERNIGHT AS SFC RIDGE AXIS PASSES THROUGH CWA.

&&

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 356 AM EDT THU SEP 18 2014

AN UPPER LEVEL TROF WILL TOP THE UPSTREAM RIDGE AND RACE SOUTHEAST
TOWARD THE WESTERN GREAT LAKES REGION THIS WEEKEND. MODEL SOLUTION
SPREADS AMONG THE GFS...CANADIAN...ECMWF STILL EXIST...WITH THE
ECMWF FASTER THAN THE GFS WITH THE TIMING OF THE INITIAL STRONGER
TROF. PREFER THE ECMWF OVERALL HANDLING OF THIS SYSTEM INCLUDING THE
TIMING AND CONVECTIVE DEVELOPMENT SATURDAY NIGHT ASSOCIATED WITH
THIS SYSTEM. AHEAD OF THE COLD FRONT...850 MB TEMPS STILL POISED TO
RISE TO AROUND 17C...SUPPORTING HIGHS NEAR 80 DEGREES SATURDAY.
CONCERN THAT WITH RELATIVELY WARM MID LEVEL TEMPS...WEAK INITIAL LOW
LEVEL FORCING AND SOMEWHAT OF A LOW LEVEL CAP ASSOCIATED WITH AN
ELEVATED MIX LAYER THESE CONDITIONS WILL KEEP MUCH OF SATURDAY DRY.
LOWERED SHOWER/STORM CHANCES OVER NORTHERN AREAS FOR THIS REASON.
ALSO SOME CONCERN THAT SUBTROPICAL MOISTURE AND REMNANTS OF ODILE
WILL REACH THE AREA THIS WEEKEND...HOWEVER...THE LATEST WPC
FORECASTS ALONG WITH MODEL DATA KEEP THIS UPPER LEVEL MOISTURE
GENERALLY SOUTH OF THE AREA. NEVERTHELESS...SOUTHERN MOISTURE TAP
SHOULD BE SUFFICIENT FOR PRECIPITABLE WATER VALUES TO RISE TO AROUND
1.5 INCHES. THE INITIAL COLD FRONT SHOULD MOVE ACROSS THE AREA LATE
SATURDAY NIGHT/EARLY SUNDAY MORNING.  A SECONDARY SURGE OF COOL AIR
SHOULD REACH THE AREA SUNDAY NIGHT. FOR NOW...HAVE KEPT SUNDAY NIGHT
AND MONDAY DRY...BUT THERE IS AN OUTSIDE CHANCE THERE COULD BE SOME
SHOWERS ASSOCIATED WITH A SECONDARY UPPER LEVEL TROF AND COLD
FRONT...ESPECIALLY DOWNWIND OF LAKE MICHIGAN WHERE DELTA T VALUES
SHOULD RISE TO NEAR 16C GIVEN A WARM LAKE WATER TEMP OF AROUND 20C
PER GOES SOUNDER. THE SURFACE HIGH PRESSURE AREA WILL BUILD INTO THE
AREA INTO MONDAY NIGHT...BRINGING AN END TO ANY SHOWERS AS WINDS
VEER NORTHEAST AND SUBSIDENCE INCREASES. THE SURFACE RIDGE OF HIGH
PRESSURE WILL REMAIN OVER THE AREA  WITH AN EAST WIND TUESDAY AND
WEDNESDAY ACCOMPANIED BY PLEASANT MIDWEEK WEATHER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 102 PM EDT THU SEP 18 2014

SFC RIDGING IN SUBSIDENT/DRY NORTHWEST FLOW SHOULD RESULT IN A
CONTINUATION OF VFR CONDITIONS/MAINLY CLEAR SKIES THROUGH THE TAF
CYCLE. COULD SEE SOME PATCHY FOG/STRATUS DEVELOPMENT TOWARD 9-12Z
FRIDAY...BUT COVERAGE/CONFIDENCE REMAINS TOO LOW FOR INCLUSION
THIS ISSUANCE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...MCD
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...STEINWEDEL


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000
FXUS63 KIWX 181702
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
102 PM EDT THU SEP 18 2014

.SYNOPSIS...
ISSUED AT 356 AM EDT THU SEP 18 2014

HIGH PRESSURE WILL REMAIN ENTRENCHED ACROSS THE OHIO VALLEY
THROUGH FRIDAY WITH DRY CONDITIONS AND MODERATING TEMPERATURES.
HIGHS THIS AFTERNOON WILL PEAK OUT IN THE UPPER 60S TO LOWER 70S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM EDT THU SEP 18 2014

RENEWED SFC RIDGING BLDG SEWD OUT OF CANADA IN BEHIND VIGOROUS SW
TROUGH AMPLIFYING EWD ACRS SE CANADA WILL RESULT IN A CONTN OF
STELLAR LT SUMMER CONDS THIS PD. HIGH THIS AFTN SHLD AGAIN NOTCH A
DEGREE OR TWO WARMER THAN YDA FOLLOWED BY SEASONABLY COOL TEMPS
OVERNIGHT AS SFC RIDGE AXIS PASSES THROUGH CWA.

&&

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 356 AM EDT THU SEP 18 2014

AN UPPER LEVEL TROF WILL TOP THE UPSTREAM RIDGE AND RACE SOUTHEAST
TOWARD THE WESTERN GREAT LAKES REGION THIS WEEKEND. MODEL SOLUTION
SPREADS AMONG THE GFS...CANADIAN...ECMWF STILL EXIST...WITH THE
ECMWF FASTER THAN THE GFS WITH THE TIMING OF THE INITIAL STRONGER
TROF. PREFER THE ECMWF OVERALL HANDLING OF THIS SYSTEM INCLUDING THE
TIMING AND CONVECTIVE DEVELOPMENT SATURDAY NIGHT ASSOCIATED WITH
THIS SYSTEM. AHEAD OF THE COLD FRONT...850 MB TEMPS STILL POISED TO
RISE TO AROUND 17C...SUPPORTING HIGHS NEAR 80 DEGREES SATURDAY.
CONCERN THAT WITH RELATIVELY WARM MID LEVEL TEMPS...WEAK INITIAL LOW
LEVEL FORCING AND SOMEWHAT OF A LOW LEVEL CAP ASSOCIATED WITH AN
ELEVATED MIX LAYER THESE CONDITIONS WILL KEEP MUCH OF SATURDAY DRY.
LOWERED SHOWER/STORM CHANCES OVER NORTHERN AREAS FOR THIS REASON.
ALSO SOME CONCERN THAT SUBTROPICAL MOISTURE AND REMNANTS OF ODILE
WILL REACH THE AREA THIS WEEKEND...HOWEVER...THE LATEST WPC
FORECASTS ALONG WITH MODEL DATA KEEP THIS UPPER LEVEL MOISTURE
GENERALLY SOUTH OF THE AREA. NEVERTHELESS...SOUTHERN MOISTURE TAP
SHOULD BE SUFFICIENT FOR PRECIPITABLE WATER VALUES TO RISE TO AROUND
1.5 INCHES. THE INITIAL COLD FRONT SHOULD MOVE ACROSS THE AREA LATE
SATURDAY NIGHT/EARLY SUNDAY MORNING.  A SECONDARY SURGE OF COOL AIR
SHOULD REACH THE AREA SUNDAY NIGHT. FOR NOW...HAVE KEPT SUNDAY NIGHT
AND MONDAY DRY...BUT THERE IS AN OUTSIDE CHANCE THERE COULD BE SOME
SHOWERS ASSOCIATED WITH A SECONDARY UPPER LEVEL TROF AND COLD
FRONT...ESPECIALLY DOWNWIND OF LAKE MICHIGAN WHERE DELTA T VALUES
SHOULD RISE TO NEAR 16C GIVEN A WARM LAKE WATER TEMP OF AROUND 20C
PER GOES SOUNDER. THE SURFACE HIGH PRESSURE AREA WILL BUILD INTO THE
AREA INTO MONDAY NIGHT...BRINGING AN END TO ANY SHOWERS AS WINDS
VEER NORTHEAST AND SUBSIDENCE INCREASES. THE SURFACE RIDGE OF HIGH
PRESSURE WILL REMAIN OVER THE AREA  WITH AN EAST WIND TUESDAY AND
WEDNESDAY ACCOMPANIED BY PLEASANT MIDWEEK WEATHER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 102 PM EDT THU SEP 18 2014

SFC RIDGING IN SUBSIDENT/DRY NORTHWEST FLOW SHOULD RESULT IN A
CONTINUATION OF VFR CONDITIONS/MAINLY CLEAR SKIES THROUGH THE TAF
CYCLE. COULD SEE SOME PATCHY FOG/STRATUS DEVELOPMENT TOWARD 9-12Z
FRIDAY...BUT COVERAGE/CONFIDENCE REMAINS TOO LOW FOR INCLUSION
THIS ISSUANCE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...MCD
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...STEINWEDEL


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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