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000
FXUS63 KDTX 230350
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1150 PM EDT MON SEP 22 2014


.AVIATION...

//DISCUSSION...

HIGH PRESSURE ACROSS THE OHIO VALLEY AND SOUTHERN GREAT LAKES WILL
MAINTAIN CLEAR SKIES AND LIGHT WINDS THROUGH THE TAF PERIOD.
CONDITIONS APPEAR TOO DRY TO PROMOTE ANYTHING OTHER THAN SOME PATCHY
GROUND FOG TOWARD DAYBREAK...NOT ENOUGH CONFIDENCE TO PLACE ANY VSBY
RESTRICTIONS IN THE TAFS.

//DTW THRESHOLD THREATS...

* NONE.

&&

.PREV DISCUSSION...ISSUED 324 PM EDT MON SEP 22 2014

SHORT TERM...TONIGHT

DEEP NORTHWEST FLOW ACTUALLY TRANSLATING TO SOME MODEST
MOISTURE ADVECTION THROUGH TONIGHT...SEE 850-700 MB THETA-E/PW
FIELDS...WHICH HAS BEEN ABLE TO PRODUCE A SWATCH OF CLOUDS ACROSS
THE WESTERN GREAT LAKES. HOWEVER...WITH THE LOSS OF DAYTIME HEATING
AND MAIN PUSH OF THE MOISTURE REMAINING NORTH OF SOUTHEAST
MICHIGAN....PLANNING ON GOING WITH MOSTLY CLEAR/CLEAR
FORECAST...WITH MINS FALLING INTO THE LOW TO MID 40S...IN LINE WITH
LATEST GUIDANCE. THERE IS A LOW CHANCE OF SOME SHALLOW FOG
DEVELOPING LATE TONIGHT...BUT CHOSE TO LEAVE MENTION OUT OF THE
ZONES.

LONG TERM...

STARTING TUESDAY AND INTO WEDNESDAY...UPPER LEVEL RIDGING WILL
CONTINUE TO HOLD BRINGING TRANQUIL CONDITIONS OVER THE AREA.  THIS
RIDGE ALONG WITH SURFACE HIGH PRESSURE WILL ALLOW FOR MOSTLY CLEAR
SKIES DURING THIS PERIOD.  TEMPERATURES REMAIN PRETTY STEADY DURING
THE WEEK...BUT EVEN WITH FULL SUN THE COOLER AIRMASS WILL KEEP TEMPS
RIGHT AROUND NORMAL FOR THIS TIME OF YEAR.  HIGHS TOP OFF IN THE
LOWER 70S WITH LOWS COOLING OFF TO AROUND 50F.  UNDER CLEAR SKIES
AND LIGHT WINDS.  THE ONLY UPCOMING CONCERN WILL BE THE POTENTIAL
FOR RADIATIONAL FOG TO DEVELOP DURING THE EARLY MORNING HOURS.

ANOMALOUS UPPER RIDGE WILL CONTINUE TO HOLD OVER MUCH OF THE EASTERN
CONUS FOR THE REMAINDER OF THE FORECAST...LIKELY ENSURING TRANQUIL
WEATHER CONTINUES WITH ABOVE NORMAL TEMPS. ONLY SOURCE OF
UNCERTAINTY MAY ARISE WITH THE UPPER LOW CURRENTLY OVER
ID/WY...THOUGH THERE IS GOOD AGREEMENT THAT IT WILL EITHER BE
ABSORBED BY THE NORTHERN STREAM WELL NORTH OF THE GREAT LAKES OR BE
UNABLE TO PENETRATE THE STRONG UPPER RIDGE.

MARINE...

WINDS WILL EASE THROUGH THE REMAINDER OF THE DAY AS HIGH PRESSURE
BUILDS IN OVER THE REGION.  HIGH PRESSURE WILL HOLD STEADY OVER THE
AREA THROUGH THE WEEK BRINGING DRY AND QUIET CONDITIONS OVER THE
MARINE AREAS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....SS/DT
MARINE.......SS


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 230350
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1150 PM EDT MON SEP 22 2014


.AVIATION...

//DISCUSSION...

HIGH PRESSURE ACROSS THE OHIO VALLEY AND SOUTHERN GREAT LAKES WILL
MAINTAIN CLEAR SKIES AND LIGHT WINDS THROUGH THE TAF PERIOD.
CONDITIONS APPEAR TOO DRY TO PROMOTE ANYTHING OTHER THAN SOME PATCHY
GROUND FOG TOWARD DAYBREAK...NOT ENOUGH CONFIDENCE TO PLACE ANY VSBY
RESTRICTIONS IN THE TAFS.

//DTW THRESHOLD THREATS...

* NONE.

&&

.PREV DISCUSSION...ISSUED 324 PM EDT MON SEP 22 2014

SHORT TERM...TONIGHT

DEEP NORTHWEST FLOW ACTUALLY TRANSLATING TO SOME MODEST
MOISTURE ADVECTION THROUGH TONIGHT...SEE 850-700 MB THETA-E/PW
FIELDS...WHICH HAS BEEN ABLE TO PRODUCE A SWATCH OF CLOUDS ACROSS
THE WESTERN GREAT LAKES. HOWEVER...WITH THE LOSS OF DAYTIME HEATING
AND MAIN PUSH OF THE MOISTURE REMAINING NORTH OF SOUTHEAST
MICHIGAN....PLANNING ON GOING WITH MOSTLY CLEAR/CLEAR
FORECAST...WITH MINS FALLING INTO THE LOW TO MID 40S...IN LINE WITH
LATEST GUIDANCE. THERE IS A LOW CHANCE OF SOME SHALLOW FOG
DEVELOPING LATE TONIGHT...BUT CHOSE TO LEAVE MENTION OUT OF THE
ZONES.

LONG TERM...

STARTING TUESDAY AND INTO WEDNESDAY...UPPER LEVEL RIDGING WILL
CONTINUE TO HOLD BRINGING TRANQUIL CONDITIONS OVER THE AREA.  THIS
RIDGE ALONG WITH SURFACE HIGH PRESSURE WILL ALLOW FOR MOSTLY CLEAR
SKIES DURING THIS PERIOD.  TEMPERATURES REMAIN PRETTY STEADY DURING
THE WEEK...BUT EVEN WITH FULL SUN THE COOLER AIRMASS WILL KEEP TEMPS
RIGHT AROUND NORMAL FOR THIS TIME OF YEAR.  HIGHS TOP OFF IN THE
LOWER 70S WITH LOWS COOLING OFF TO AROUND 50F.  UNDER CLEAR SKIES
AND LIGHT WINDS.  THE ONLY UPCOMING CONCERN WILL BE THE POTENTIAL
FOR RADIATIONAL FOG TO DEVELOP DURING THE EARLY MORNING HOURS.

ANOMALOUS UPPER RIDGE WILL CONTINUE TO HOLD OVER MUCH OF THE EASTERN
CONUS FOR THE REMAINDER OF THE FORECAST...LIKELY ENSURING TRANQUIL
WEATHER CONTINUES WITH ABOVE NORMAL TEMPS. ONLY SOURCE OF
UNCERTAINTY MAY ARISE WITH THE UPPER LOW CURRENTLY OVER
ID/WY...THOUGH THERE IS GOOD AGREEMENT THAT IT WILL EITHER BE
ABSORBED BY THE NORTHERN STREAM WELL NORTH OF THE GREAT LAKES OR BE
UNABLE TO PENETRATE THE STRONG UPPER RIDGE.

MARINE...

WINDS WILL EASE THROUGH THE REMAINDER OF THE DAY AS HIGH PRESSURE
BUILDS IN OVER THE REGION.  HIGH PRESSURE WILL HOLD STEADY OVER THE
AREA THROUGH THE WEEK BRINGING DRY AND QUIET CONDITIONS OVER THE
MARINE AREAS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....SS/DT
MARINE.......SS


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 222315
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
715 PM EDT MON SEP 22 2014


.AVIATION...

//DISCUSSION...

THERE IS A REGION OF STRATO CU BASED BETWEEN 4K AND 5K FEET ACROSS
THE SAGINAW VALLEY AND THUMB ASSOCIATED WITH A SHALLOW LAYER OF
MOISTURE TRAVERSING THE REGION. THIS MOISTURE WILL MOVE EAST OF THE
REGION THIS EVENING. THIS ALONG WITH THE LOSS OF DAYTIME HEATING
WILL CAUSE THESE CLOUDS TO QUICKLY ERODE BY OR SHORTLY AFTER 00Z.
OTHERWISE...HIGH PRESSURE WILL MAINTAIN CLEAR SKIES AND LIGHT WINDS
THROUGH THE NIGHT.

//DTW THRESHOLD THREATS...

* NONE.

&&

.PREV DISCUSSION...ISSUED 324 PM EDT MON SEP 22 2014

SHORT TERM...TONIGHT

DEEP NORTHWEST FLOW ACTUALLY TRANSLATING TO SOME MODEST
MOISTURE ADVECTION THROUGH TONIGHT...SEE 850-700 MB THETA-E/PW
FIELDS...WHICH HAS BEEN ABLE TO PRODUCE A SWATCH OF CLOUDS ACROSS
THE WESTERN GREAT LAKES. HOWEVER...WITH THE LOSS OF DAYTIME HEATING
AND MAIN PUSH OF THE MOISTURE REMAINING NORTH OF SOUTHEAST
MICHIGAN....PLANNING ON GOING WITH MOSTLY CLEAR/CLEAR
FORECAST...WITH MINS FALLING INTO THE LOW TO MID 40S...IN LINE WITH
LATEST GUIDANCE. THERE IS A LOW CHANCE OF SOME SHALLOW FOG
DEVELOPING LATE TONIGHT...BUT CHOSE TO LEAVE MENTION OUT OF THE
ZONES.

LONG TERM...

STARTING TUESDAY AND INTO WEDNESDAY...UPPER LEVEL RIDGING WILL
CONTINUE TO HOLD BRINGING TRANQUIL CONDITIONS OVER THE AREA.  THIS
RIDGE ALONG WITH SURFACE HIGH PRESSURE WILL ALLOW FOR MOSTLY CLEAR
SKIES DURING THIS PERIOD.  TEMPERATURES REMAIN PRETTY STEADY DURING
THE WEEK...BUT EVEN WITH FULL SUN THE COOLER AIRMASS WILL KEEP TEMPS
RIGHT AROUND NORMAL FOR THIS TIME OF YEAR.  HIGHS TOP OFF IN THE
LOWER 70S WITH LOWS COOLING OFF TO AROUND 50F.  UNDER CLEAR SKIES
AND LIGHT WINDS.  THE ONLY UPCOMING CONCERN WILL BE THE POTENTIAL
FOR RADIATIONAL FOG TO DEVELOP DURING THE EARLY MORNING HOURS.

ANOMALOUS UPPER RIDGE WILL CONTINUE TO HOLD OVER MUCH OF THE EASTERN
CONUS FOR THE REMAINDER OF THE FORECAST...LIKELY ENSURING TRANQUIL
WEATHER CONTINUES WITH ABOVE NORMAL TEMPS. ONLY SOURCE OF
UNCERTAINTY MAY ARISE WITH THE UPPER LOW CURRENTLY OVER
ID/WY...THOUGH THERE IS GOOD AGREEMENT THAT IT WILL EITHER BE
ABSORBED BY THE NORTHERN STREAM WELL NORTH OF THE GREAT LAKES OR BE
UNABLE TO PENETRATE THE STRONG UPPER RIDGE.

MARINE...

WINDS WILL EASE THROUGH THE REMAINDER OF THE DAY AS HIGH PRESSURE
BUILDS IN OVER THE REGION.  HIGH PRESSURE WILL HOLD STEADY OVER THE
AREA THROUGH THE WEEK BRINGING DRY AND QUIET CONDITIONS OVER THE
MARINE AREAS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....SS/DT
MARINE.......SS


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 222315
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
715 PM EDT MON SEP 22 2014


.AVIATION...

//DISCUSSION...

THERE IS A REGION OF STRATO CU BASED BETWEEN 4K AND 5K FEET ACROSS
THE SAGINAW VALLEY AND THUMB ASSOCIATED WITH A SHALLOW LAYER OF
MOISTURE TRAVERSING THE REGION. THIS MOISTURE WILL MOVE EAST OF THE
REGION THIS EVENING. THIS ALONG WITH THE LOSS OF DAYTIME HEATING
WILL CAUSE THESE CLOUDS TO QUICKLY ERODE BY OR SHORTLY AFTER 00Z.
OTHERWISE...HIGH PRESSURE WILL MAINTAIN CLEAR SKIES AND LIGHT WINDS
THROUGH THE NIGHT.

//DTW THRESHOLD THREATS...

* NONE.

&&

.PREV DISCUSSION...ISSUED 324 PM EDT MON SEP 22 2014

SHORT TERM...TONIGHT

DEEP NORTHWEST FLOW ACTUALLY TRANSLATING TO SOME MODEST
MOISTURE ADVECTION THROUGH TONIGHT...SEE 850-700 MB THETA-E/PW
FIELDS...WHICH HAS BEEN ABLE TO PRODUCE A SWATCH OF CLOUDS ACROSS
THE WESTERN GREAT LAKES. HOWEVER...WITH THE LOSS OF DAYTIME HEATING
AND MAIN PUSH OF THE MOISTURE REMAINING NORTH OF SOUTHEAST
MICHIGAN....PLANNING ON GOING WITH MOSTLY CLEAR/CLEAR
FORECAST...WITH MINS FALLING INTO THE LOW TO MID 40S...IN LINE WITH
LATEST GUIDANCE. THERE IS A LOW CHANCE OF SOME SHALLOW FOG
DEVELOPING LATE TONIGHT...BUT CHOSE TO LEAVE MENTION OUT OF THE
ZONES.

LONG TERM...

STARTING TUESDAY AND INTO WEDNESDAY...UPPER LEVEL RIDGING WILL
CONTINUE TO HOLD BRINGING TRANQUIL CONDITIONS OVER THE AREA.  THIS
RIDGE ALONG WITH SURFACE HIGH PRESSURE WILL ALLOW FOR MOSTLY CLEAR
SKIES DURING THIS PERIOD.  TEMPERATURES REMAIN PRETTY STEADY DURING
THE WEEK...BUT EVEN WITH FULL SUN THE COOLER AIRMASS WILL KEEP TEMPS
RIGHT AROUND NORMAL FOR THIS TIME OF YEAR.  HIGHS TOP OFF IN THE
LOWER 70S WITH LOWS COOLING OFF TO AROUND 50F.  UNDER CLEAR SKIES
AND LIGHT WINDS.  THE ONLY UPCOMING CONCERN WILL BE THE POTENTIAL
FOR RADIATIONAL FOG TO DEVELOP DURING THE EARLY MORNING HOURS.

ANOMALOUS UPPER RIDGE WILL CONTINUE TO HOLD OVER MUCH OF THE EASTERN
CONUS FOR THE REMAINDER OF THE FORECAST...LIKELY ENSURING TRANQUIL
WEATHER CONTINUES WITH ABOVE NORMAL TEMPS. ONLY SOURCE OF
UNCERTAINTY MAY ARISE WITH THE UPPER LOW CURRENTLY OVER
ID/WY...THOUGH THERE IS GOOD AGREEMENT THAT IT WILL EITHER BE
ABSORBED BY THE NORTHERN STREAM WELL NORTH OF THE GREAT LAKES OR BE
UNABLE TO PENETRATE THE STRONG UPPER RIDGE.

MARINE...

WINDS WILL EASE THROUGH THE REMAINDER OF THE DAY AS HIGH PRESSURE
BUILDS IN OVER THE REGION.  HIGH PRESSURE WILL HOLD STEADY OVER THE
AREA THROUGH THE WEEK BRINGING DRY AND QUIET CONDITIONS OVER THE
MARINE AREAS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....SS/DT
MARINE.......SS


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 221924
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
324 PM EDT MON SEP 22 2014

.SHORT TERM...TONIGHT

DEEP NORTHWEST FLOW ACTUALLY TRANSLATING TO SOME MODEST
MOISTURE ADVECTION THROUGH TONIGHT...SEE 850-700 MB THETA-E/PW
FIELDS...WHICH HAS BEEN ABLE TO PRODUCE A SWATCH OF CLOUDS ACROSS
THE WESTERN GREAT LAKES. HOWEVER...WITH THE LOSS OF DAYTIME HEATING
AND MAIN PUSH OF THE MOISTURE REMAINING NORTH OF SOUTHEAST
MICHIGAN....PLANNING ON GOING WITH MOSTLY CLEAR/CLEAR
FORECAST...WITH MINS FALLING INTO THE LOW TO MID 40S...IN LINE WITH
LATEST GUIDANCE. THERE IS A LOW CHANCE OF SOME SHALLOW FOG
DEVELOPING LATE TONIGHT...BUT CHOSE TO LEAVE MENTION OUT OF THE
ZONES.

&&

.LONG TERM...

STARTING TUESDAY AND INTO WEDNESDAY...UPPER LEVEL RIDGING WILL
CONTINUE TO HOLD BRINGING TRANQUIL CONDITIONS OVER THE AREA.  THIS
RIDGE ALONG WITH SURFACE HIGH PRESSURE WILL ALLOW FOR MOSTLY CLEAR
SKIES DURING THIS PERIOD.  TEMPERATURES REMAIN PRETTY STEADY DURING
THE WEEK...BUT EVEN WITH FULL SUN THE COOLER AIRMASS WILL KEEP TEMPS
RIGHT AROUND NORMAL FOR THIS TIME OF YEAR.  HIGHS TOP OFF IN THE
LOWER 70S WITH LOWS COOLING OFF TO AROUND 50F.  UNDER CLEAR SKIES
AND LIGHT WINDS.  THE ONLY UPCOMING CONCERN WILL BE THE POTENTIAL
FOR RADIATIONAL FOG TO DEVELOP DURING THE EARLY MORNING HOURS.

ANOMALOUS UPPER RIDGE WILL CONTINUE TO HOLD OVER MUCH OF THE EASTERN
CONUS FOR THE REMAINDER OF THE FORECAST...LIKELY ENSURING TRANQUIL
WEATHER CONTINUES WITH ABOVE NORMAL TEMPS. ONLY SOURCE OF
UNCERTAINTY MAY ARISE WITH THE UPPER LOW CURRENTLY OVER
ID/WY...THOUGH THERE IS GOOD AGREEMENT THAT IT WILL EITHER BE
ABSORBED BY THE NORTHERN STREAM WELL NORTH OF THE GREAT LAKES OR BE
UNABLE TO PENETRATE THE STRONG UPPER RIDGE.

&&

.MARINE...

WINDS WILL EASE THROUGH THE REMAINDER OF THE DAY AS HIGH PRESSURE
BUILDS IN OVER THE REGION.  HIGH PRESSURE WILL HOLD STEADY OVER THE
AREA THROUGH THE WEEK BRINGING DRY AND QUIET CONDITIONS OVER THE
MARINE AREAS.

&&

.AVIATION...ISSUED 1250 PM EDT MON SEP 22 2014

//DISCUSSION...

12Z DTX SOUNDING SHOWED A VERY STRONG INVERSION JUST UNDER 5000
FEET. THE INVERSION HAS LOWERED FURTHER...AND CLOUDS HAVE PRETTY
MUCH MIXED OUT...SETTING US UP FOR CLEAR TO MOSTLY CLEAR SKIES
THROUGH THE REST OF THE TAF PERIOD AS HIGH PRESSURE DOMINATES. THE
ONLY CONCERN IS THE LOW CHANCE OF SHALLOW RADIATION FOG LATE NIGHT.

//DTW THRESHOLD THREATS...

* NONE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...SF
LONG TERM....SS/DT
MARINE.......SS
AVIATION.....SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 221924
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
324 PM EDT MON SEP 22 2014

.SHORT TERM...TONIGHT

DEEP NORTHWEST FLOW ACTUALLY TRANSLATING TO SOME MODEST
MOISTURE ADVECTION THROUGH TONIGHT...SEE 850-700 MB THETA-E/PW
FIELDS...WHICH HAS BEEN ABLE TO PRODUCE A SWATCH OF CLOUDS ACROSS
THE WESTERN GREAT LAKES. HOWEVER...WITH THE LOSS OF DAYTIME HEATING
AND MAIN PUSH OF THE MOISTURE REMAINING NORTH OF SOUTHEAST
MICHIGAN....PLANNING ON GOING WITH MOSTLY CLEAR/CLEAR
FORECAST...WITH MINS FALLING INTO THE LOW TO MID 40S...IN LINE WITH
LATEST GUIDANCE. THERE IS A LOW CHANCE OF SOME SHALLOW FOG
DEVELOPING LATE TONIGHT...BUT CHOSE TO LEAVE MENTION OUT OF THE
ZONES.

&&

.LONG TERM...

STARTING TUESDAY AND INTO WEDNESDAY...UPPER LEVEL RIDGING WILL
CONTINUE TO HOLD BRINGING TRANQUIL CONDITIONS OVER THE AREA.  THIS
RIDGE ALONG WITH SURFACE HIGH PRESSURE WILL ALLOW FOR MOSTLY CLEAR
SKIES DURING THIS PERIOD.  TEMPERATURES REMAIN PRETTY STEADY DURING
THE WEEK...BUT EVEN WITH FULL SUN THE COOLER AIRMASS WILL KEEP TEMPS
RIGHT AROUND NORMAL FOR THIS TIME OF YEAR.  HIGHS TOP OFF IN THE
LOWER 70S WITH LOWS COOLING OFF TO AROUND 50F.  UNDER CLEAR SKIES
AND LIGHT WINDS.  THE ONLY UPCOMING CONCERN WILL BE THE POTENTIAL
FOR RADIATIONAL FOG TO DEVELOP DURING THE EARLY MORNING HOURS.

ANOMALOUS UPPER RIDGE WILL CONTINUE TO HOLD OVER MUCH OF THE EASTERN
CONUS FOR THE REMAINDER OF THE FORECAST...LIKELY ENSURING TRANQUIL
WEATHER CONTINUES WITH ABOVE NORMAL TEMPS. ONLY SOURCE OF
UNCERTAINTY MAY ARISE WITH THE UPPER LOW CURRENTLY OVER
ID/WY...THOUGH THERE IS GOOD AGREEMENT THAT IT WILL EITHER BE
ABSORBED BY THE NORTHERN STREAM WELL NORTH OF THE GREAT LAKES OR BE
UNABLE TO PENETRATE THE STRONG UPPER RIDGE.

&&

.MARINE...

WINDS WILL EASE THROUGH THE REMAINDER OF THE DAY AS HIGH PRESSURE
BUILDS IN OVER THE REGION.  HIGH PRESSURE WILL HOLD STEADY OVER THE
AREA THROUGH THE WEEK BRINGING DRY AND QUIET CONDITIONS OVER THE
MARINE AREAS.

&&

.AVIATION...ISSUED 1250 PM EDT MON SEP 22 2014

//DISCUSSION...

12Z DTX SOUNDING SHOWED A VERY STRONG INVERSION JUST UNDER 5000
FEET. THE INVERSION HAS LOWERED FURTHER...AND CLOUDS HAVE PRETTY
MUCH MIXED OUT...SETTING US UP FOR CLEAR TO MOSTLY CLEAR SKIES
THROUGH THE REST OF THE TAF PERIOD AS HIGH PRESSURE DOMINATES. THE
ONLY CONCERN IS THE LOW CHANCE OF SHALLOW RADIATION FOG LATE NIGHT.

//DTW THRESHOLD THREATS...

* NONE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...SF
LONG TERM....SS/DT
MARINE.......SS
AVIATION.....SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 221650
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1250 PM EDT MON SEP 22 2014


.AVIATION...

//DISCUSSION...

12Z DTX SOUNDING SHOWED A VERY STRONG INVERSION JUST UNDER 5000
FEET. THE INVERSION HAS LOWERED FURTHER...AND CLOUDS HAVE PRETTY
MUCH MIXED OUT...SETTING US UP FOR CLEAR TO MOSTLY CLEAR SKIES
THROUGH THE REST OF THE TAF PERIOD AS HIGH PRESSURE DOMINATES. THE
ONLY CONCERN IS THE LOW CHANCE OF SHALLOW RADIATION FOG LATE NIGHT.

//DTW THRESHOLD THREATS...

* NONE.

&&

.PREV DISCUSSION...ISSUED 250 AM EDT MON SEP 22 2014

SHORT TERM...TODAY AND TONIGHT

AN UPPER LEVEL TROUGH AND ASSOCIATED SHORTWAVE...CLEARLY VISIBLE ON
SATELLITE IMAGERY...ARE CURRENTLY MAKING THEIR WAY THROUGH THE
CENTRAL GREAT LAKES EARLY THIS MORNING. RIDGING WILL BUILD IN BEHIND
THE TROUGH THROUGHOUT THE DAYTIME HOURS AS DRIER AIR ADVECTS IN FROM
THE WEST AS SURFACE WINDS BACK TO THE WEST THIS AFTERNOON...AND
EVENTUALLY SOUTHWEST DURING THE OVERNIGHT HOURS. AS THE 00Z KDTX
RAOB SOUNDING INDICATES THERE IS QUITE A BIT OF MOISTURE TRAPPED IN
THE LOW LEVELS...AS EVIDENCED BY THE STRATUS DECK CURRENTLY IN
PLACE. MODEL SOUNDINGS AND UPSTREAM OBSERVATIONS INDICATE THESE
CLOUDS WILL DISSIPATE AS THE HIGH TRACKS EAST AS EVIDENCED BY THE
VERY DRY AIR LOCATED OVER THE WESTERN GREAT LAKES ASSOCIATED WITH
THE HIGH.

DESPITE CLEARING SKIES DURING THE AFTERNOON HOURS...SUNSHINE WILL
NOT BE ENOUGH TO MAKE UP FOR THE VERY COLD AIRMASS AND SHALLOW
MIXING DEPTHS IN PLACE ACROSS THE AREA. THESE CONDITIONS LOOK TO
LIMIT HIGH TEMPERATURES TO AROUND 60 DEGREES THIS AFTERNOON.
ALTHOUGH CLEAR SKIES AND LIGHT WINDS WILL PROVIDE IDEAL RADIATING
CONDITIONS TONIGHT WITH THE HIGH JUST TO OUR SOUTH...THE AREA WILL
ALREADY BE RECOVERING FROM THE SHOT OF COLD AIR AS 850 MB
TEMPERATURES IMPROVE TO AROUND 10 DEGREES DURING THE OVERNIGHT
HOURS. STILL...LOW TEMPERATURES LOOK TO BOTTOM OUT IN THE MIDDLE 40S
ACROSS MUCH OF THE AREA.

LONG TERM...

A PROLONGED PERIOD OF UPPER RIDGING IS POISED TO TAKE HOLD OF THE
GREAT LAKES REGION RESULTING IN AN EXTENDED PERIOD OF MOSTLY SUNNY
SKIES...TEMPERATURES IN THE 70S...AND DRY WEATHER. THE COOLEST DAY OF
THE LONG TERM PERIOD WILL BE THE FIRST. TUESDAY WILL BE
CHARACTERIZED BY A REBOUNDING THERMAL FIELD AS TODAY`S THERMAL
TROUGH EXITS EAST. UPPER RIDGING WILL BUILD IN THROUGH THE DAY,
BEING NUDGED EAST BY THE EASTWARD PROGRESSION OF THE GREAT BASIN
CLOSED LOW. H85 TEMPS WILL EVENTUALLY APPROACH 12C BY 00Z WED, BUT
IT WILL BE TOO LITTLE TOO LATE AS FAR AS MIXING GOES. AS A RESULT,
HIGHS WILL BARELY TOUCH 70 IN MOST SPOTS.

THE REMAINDER OF THE LONG TERM WILL BE BAROTROPIC IN CHARACTER BUT
STRONGLY CAPPED. A PIECE OF THE CLOSED LOW WILL SHEAR EAST AS IT IS
ABSORBED BACK INTO THE PREVAILING WESTERLIES ON WEDNESDAY AFTERNOON.
THIS WILL OCCUR OVER THE WESTERN GREAT LAKES AND WILL BE OF NO
CONSEQUENCE LOCALLY OTHER THAN A FEW MID/HIGH CLOUDS THURSDAY. THE
REMAINDER OF THAT LOW WILL CUT BACK TO THE WEST...BEST ILLUSTRATED BY
THE 0.6 PVU SURFACE AT 500MB...AS IT WORKS IN CONCERT WITH THE
DEEPENING WEST COAST TROUGH TO FORCE A WAVE BREAK OVER THE CONUS.
THE RESULTANT CUTOFF RIDGE WILL SETTLE OVER THE GREAT LAKES FOR THE
WEEKEND...ENSURING CONTINUED CAPPING. THIS RIDGE WILL CARRY WITH IT
LITTLE IN THE WAY WAY OF WARMER AIR IN THE LOW-LEVELS DESPITE
PROGGED H5 HEIGHTS UP TO 592DM OVER MICHIGAN. AS A RESULT...ONLY
MINOR TEMPERATURE MODIFICATION INTO THE UPPER 70S...PERHAPS TOUCHING
80 ON A COUPLE OF OVERACHIEVING DAYS, IS EXPECTED. WITH CLEAR SKIES
AND A LIGHT GRADIENT...MORNING LOWS SHOULD STILL HOVER NEAR NORMAL
VALUES IN THE LOW/MID 50S EACH MORNING. A COUPLE MORNINGS FEATURING
RADIATION FOG WILL ALSO BE POSSIBLE.

MARINE...

GUSTY NORTHWEST WINDS WILL BACK TO THE WEST AND EASE THROUGH THE
DAY. SUBSIDING WAVE HEIGHTS WILL SOON TO FOLLOW WHICH WILL FINALLY
ALLOW THE POSTED SMALL CRAFT ADVISORIES FOR THE NEARSHORE WATERS OF
LAKE HURON TO EXPIRE LATER TODAY. THE REMAINDER OF THE FORECAST
PERIOD WILL FEATURE LIGHT TO OCCASIONALLY MODERATE WINDS WITH NO
PRECIPITATION.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....SF
SHORT TERM...KURIMSKI
LONG TERM....JVC
MARINE.......JVC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 221650
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1250 PM EDT MON SEP 22 2014


.AVIATION...

//DISCUSSION...

12Z DTX SOUNDING SHOWED A VERY STRONG INVERSION JUST UNDER 5000
FEET. THE INVERSION HAS LOWERED FURTHER...AND CLOUDS HAVE PRETTY
MUCH MIXED OUT...SETTING US UP FOR CLEAR TO MOSTLY CLEAR SKIES
THROUGH THE REST OF THE TAF PERIOD AS HIGH PRESSURE DOMINATES. THE
ONLY CONCERN IS THE LOW CHANCE OF SHALLOW RADIATION FOG LATE NIGHT.

//DTW THRESHOLD THREATS...

* NONE.

&&

.PREV DISCUSSION...ISSUED 250 AM EDT MON SEP 22 2014

SHORT TERM...TODAY AND TONIGHT

AN UPPER LEVEL TROUGH AND ASSOCIATED SHORTWAVE...CLEARLY VISIBLE ON
SATELLITE IMAGERY...ARE CURRENTLY MAKING THEIR WAY THROUGH THE
CENTRAL GREAT LAKES EARLY THIS MORNING. RIDGING WILL BUILD IN BEHIND
THE TROUGH THROUGHOUT THE DAYTIME HOURS AS DRIER AIR ADVECTS IN FROM
THE WEST AS SURFACE WINDS BACK TO THE WEST THIS AFTERNOON...AND
EVENTUALLY SOUTHWEST DURING THE OVERNIGHT HOURS. AS THE 00Z KDTX
RAOB SOUNDING INDICATES THERE IS QUITE A BIT OF MOISTURE TRAPPED IN
THE LOW LEVELS...AS EVIDENCED BY THE STRATUS DECK CURRENTLY IN
PLACE. MODEL SOUNDINGS AND UPSTREAM OBSERVATIONS INDICATE THESE
CLOUDS WILL DISSIPATE AS THE HIGH TRACKS EAST AS EVIDENCED BY THE
VERY DRY AIR LOCATED OVER THE WESTERN GREAT LAKES ASSOCIATED WITH
THE HIGH.

DESPITE CLEARING SKIES DURING THE AFTERNOON HOURS...SUNSHINE WILL
NOT BE ENOUGH TO MAKE UP FOR THE VERY COLD AIRMASS AND SHALLOW
MIXING DEPTHS IN PLACE ACROSS THE AREA. THESE CONDITIONS LOOK TO
LIMIT HIGH TEMPERATURES TO AROUND 60 DEGREES THIS AFTERNOON.
ALTHOUGH CLEAR SKIES AND LIGHT WINDS WILL PROVIDE IDEAL RADIATING
CONDITIONS TONIGHT WITH THE HIGH JUST TO OUR SOUTH...THE AREA WILL
ALREADY BE RECOVERING FROM THE SHOT OF COLD AIR AS 850 MB
TEMPERATURES IMPROVE TO AROUND 10 DEGREES DURING THE OVERNIGHT
HOURS. STILL...LOW TEMPERATURES LOOK TO BOTTOM OUT IN THE MIDDLE 40S
ACROSS MUCH OF THE AREA.

LONG TERM...

A PROLONGED PERIOD OF UPPER RIDGING IS POISED TO TAKE HOLD OF THE
GREAT LAKES REGION RESULTING IN AN EXTENDED PERIOD OF MOSTLY SUNNY
SKIES...TEMPERATURES IN THE 70S...AND DRY WEATHER. THE COOLEST DAY OF
THE LONG TERM PERIOD WILL BE THE FIRST. TUESDAY WILL BE
CHARACTERIZED BY A REBOUNDING THERMAL FIELD AS TODAY`S THERMAL
TROUGH EXITS EAST. UPPER RIDGING WILL BUILD IN THROUGH THE DAY,
BEING NUDGED EAST BY THE EASTWARD PROGRESSION OF THE GREAT BASIN
CLOSED LOW. H85 TEMPS WILL EVENTUALLY APPROACH 12C BY 00Z WED, BUT
IT WILL BE TOO LITTLE TOO LATE AS FAR AS MIXING GOES. AS A RESULT,
HIGHS WILL BARELY TOUCH 70 IN MOST SPOTS.

THE REMAINDER OF THE LONG TERM WILL BE BAROTROPIC IN CHARACTER BUT
STRONGLY CAPPED. A PIECE OF THE CLOSED LOW WILL SHEAR EAST AS IT IS
ABSORBED BACK INTO THE PREVAILING WESTERLIES ON WEDNESDAY AFTERNOON.
THIS WILL OCCUR OVER THE WESTERN GREAT LAKES AND WILL BE OF NO
CONSEQUENCE LOCALLY OTHER THAN A FEW MID/HIGH CLOUDS THURSDAY. THE
REMAINDER OF THAT LOW WILL CUT BACK TO THE WEST...BEST ILLUSTRATED BY
THE 0.6 PVU SURFACE AT 500MB...AS IT WORKS IN CONCERT WITH THE
DEEPENING WEST COAST TROUGH TO FORCE A WAVE BREAK OVER THE CONUS.
THE RESULTANT CUTOFF RIDGE WILL SETTLE OVER THE GREAT LAKES FOR THE
WEEKEND...ENSURING CONTINUED CAPPING. THIS RIDGE WILL CARRY WITH IT
LITTLE IN THE WAY WAY OF WARMER AIR IN THE LOW-LEVELS DESPITE
PROGGED H5 HEIGHTS UP TO 592DM OVER MICHIGAN. AS A RESULT...ONLY
MINOR TEMPERATURE MODIFICATION INTO THE UPPER 70S...PERHAPS TOUCHING
80 ON A COUPLE OF OVERACHIEVING DAYS, IS EXPECTED. WITH CLEAR SKIES
AND A LIGHT GRADIENT...MORNING LOWS SHOULD STILL HOVER NEAR NORMAL
VALUES IN THE LOW/MID 50S EACH MORNING. A COUPLE MORNINGS FEATURING
RADIATION FOG WILL ALSO BE POSSIBLE.

MARINE...

GUSTY NORTHWEST WINDS WILL BACK TO THE WEST AND EASE THROUGH THE
DAY. SUBSIDING WAVE HEIGHTS WILL SOON TO FOLLOW WHICH WILL FINALLY
ALLOW THE POSTED SMALL CRAFT ADVISORIES FOR THE NEARSHORE WATERS OF
LAKE HURON TO EXPIRE LATER TODAY. THE REMAINDER OF THE FORECAST
PERIOD WILL FEATURE LIGHT TO OCCASIONALLY MODERATE WINDS WITH NO
PRECIPITATION.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....SF
SHORT TERM...KURIMSKI
LONG TERM....JVC
MARINE.......JVC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 221111
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
711 AM EDT MON SEP 22 2014


.AVIATION...

//DISCUSSION...

A LAYER OF STRATUS WILL DISSIPATE THIS MORNING AS DRIER AIR ADVECTS
IN FROM THE WEST. IR SATELLITE IMAGERY SHOWS THIS DECK ERODING OVER
WESTERN MICHIGAN. ONCE THE STRATUS DISSIPATES MOSTLY CLEAR SKIES ARE
EXPECTED FOR THE REST OF THE TAF PERIOD WITH LIGHT NORTHWESTERLY
WINDS BACKING TO THE WEST SOUTHWEST OVERNIGHT.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT EARLY THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 250 AM EDT MON SEP 22 2014

SHORT TERM...TODAY AND TONIGHT

AN UPPER LEVEL TROUGH AND ASSOCIATED SHORTWAVE...CLEARLY VISIBLE ON
SATELLITE IMAGERY...ARE CURRENTLY MAKING THEIR WAY THROUGH THE
CENTRAL GREAT LAKES EARLY THIS MORNING. RIDGING WILL BUILD IN BEHIND
THE TROUGH THROUGHOUT THE DAYTIME HOURS AS DRIER AIR ADVECTS IN FROM
THE WEST AS SURFACE WINDS BACK TO THE WEST THIS AFTERNOON...AND
EVENTUALLY SOUTHWEST DURING THE OVERNIGHT HOURS. AS THE 00Z KDTX
RAOB SOUNDING INDICATES THERE IS QUITE A BIT OF MOISTURE TRAPPED IN
THE LOW LEVELS...AS EVIDENCED BY THE STRATUS DECK CURRENTLY IN
PLACE. MODEL SOUNDINGS AND UPSTREAM OBSERVATIONS INDICATE THESE
CLOUDS WILL DISSIPATE AS THE HIGH TRACKS EAST AS EVIDENCED BY THE
VERY DRY AIR LOCATED OVER THE WESTERN GREAT LAKES ASSOCIATED WITH
THE HIGH.

DESPITE CLEARING SKIES DURING THE AFTERNOON HOURS...SUNSHINE WILL
NOT BE ENOUGH TO MAKE UP FOR THE VERY COLD AIRMASS AND SHALLOW
MIXING DEPTHS IN PLACE ACROSS THE AREA. THESE CONDITIONS LOOK TO
LIMIT HIGH TEMPERATURES TO AROUND 60 DEGREES THIS AFTERNOON.
ALTHOUGH CLEAR SKIES AND LIGHT WINDS WILL PROVIDE IDEAL RADIATING
CONDITIONS TONIGHT WITH THE HIGH JUST TO OUR SOUTH...THE AREA WILL
ALREADY BE RECOVERING FROM THE SHOT OF COLD AIR AS 850 MB
TEMPERATURES IMPROVE TO AROUND 10 DEGREES DURING THE OVERNIGHT
HOURS. STILL...LOW TEMPERATURES LOOK TO BOTTOM OUT IN THE MIDDLE 40S
ACROSS MUCH OF THE AREA.

LONG TERM...

A PROLONGED PERIOD OF UPPER RIDGING IS POISED TO TAKE HOLD OF THE
GREAT LAKES REGION RESULTING IN AN EXTENDED PERIOD OF MOSTLY SUNNY
SKIES...TEMPERATURES IN THE 70S...AND DRY WEATHER. THE COOLEST DAY OF
THE LONG TERM PERIOD WILL BE THE FIRST. TUESDAY WILL BE
CHARACTERIZED BY A REBOUNDING THERMAL FIELD AS TODAY`S THERMAL
TROUGH EXITS EAST. UPPER RIDGING WILL BUILD IN THROUGH THE DAY,
BEING NUDGED EAST BY THE EASTWARD PROGRESSION OF THE GREAT BASIN
CLOSED LOW. H85 TEMPS WILL EVENTUALLY APPROACH 12C BY 00Z WED, BUT
IT WILL BE TOO LITTLE TOO LATE AS FAR AS MIXING GOES. AS A RESULT,
HIGHS WILL BARELY TOUCH 70 IN MOST SPOTS.

THE REMAINDER OF THE LONG TERM WILL BE BAROTROPIC IN CHARACTER BUT
STRONGLY CAPPED. A PIECE OF THE CLOSED LOW WILL SHEAR EAST AS IT IS
ABSORBED BACK INTO THE PREVAILING WESTERLIES ON WEDNESDAY AFTERNOON.
THIS WILL OCCUR OVER THE WESTERN GREAT LAKES AND WILL BE OF NO
CONSEQUENCE LOCALLY OTHER THAN A FEW MID/HIGH CLOUDS THURSDAY. THE
REMAINDER OF THAT LOW WILL CUT BACK TO THE WEST...BEST ILLUSTRATED BY
THE 0.6 PVU SURFACE AT 500MB...AS IT WORKS IN CONCERT WITH THE
DEEPENING WEST COAST TROUGH TO FORCE A WAVE BREAK OVER THE CONUS.
THE RESULTANT CUTOFF RIDGE WILL SETTLE OVER THE GREAT LAKES FOR THE
WEEKEND...ENSURING CONTINUED CAPPING. THIS RIDGE WILL CARRY WITH IT
LITTLE IN THE WAY WAY OF WARMER AIR IN THE LOW-LEVELS DESPITE
PROGGED H5 HEIGHTS UP TO 592DM OVER MICHIGAN. AS A RESULT...ONLY
MINOR TEMPERATURE MODIFICATION INTO THE UPPER 70S...PERHAPS TOUCHING
80 ON A COUPLE OF OVERACHIEVING DAYS, IS EXPECTED. WITH CLEAR SKIES
AND A LIGHT GRADIENT...MORNING LOWS SHOULD STILL HOVER NEAR NORMAL
VALUES IN THE LOW/MID 50S EACH MORNING. A COUPLE MORNINGS FEATURING
RADIATION FOG WILL ALSO BE POSSIBLE.

MARINE...

GUSTY NORTHWEST WINDS WILL BACK TO THE WEST AND EASE THROUGH THE
DAY. SUBSIDING WAVE HEIGHTS WILL SOON TO FOLLOW WHICH WILL FINALLY
ALLOW THE POSTED SMALL CRAFT ADVISORIES FOR THE NEARSHORE WATERS OF
LAKE HURON TO EXPIRE LATER TODAY. THE REMAINDER OF THE FORECAST
PERIOD WILL FEATURE LIGHT TO OCCASIONALLY MODERATE WINDS WITH NO
PRECIPITATION.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
     HURON INCLUDING OUTER SAGINAW BAY...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....JVC
MARINE.......JVC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 220650
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
250 AM EDT MON SEP 22 2014

.SHORT TERM...TODAY AND TONIGHT

AN UPPER LEVEL TROUGH AND ASSOCIATED SHORTWAVE...CLEARLY VISIBLE ON
SATELLITE IMAGERY...ARE CURRENTLY MAKING THEIR WAY THROUGH THE
CENTRAL GREAT LAKES EARLY THIS MORNING. RIDGING WILL BUILD IN BEHIND
THE TROUGH THROUGHOUT THE DAYTIME HOURS AS DRIER AIR ADVECTS IN FROM
THE WEST AS SURFACE WINDS BACK TO THE WEST THIS AFTERNOON...AND
EVENTUALLY SOUTHWEST DURING THE OVERNIGHT HOURS. AS THE 00Z KDTX
RAOB SOUNDING INDICATES THERE IS QUITE A BIT OF MOISTURE TRAPPED IN
THE LOW LEVELS...AS EVIDENCED BY THE STRATUS DECK CURRENTLY IN
PLACE. MODEL SOUNDINGS AND UPSTREAM OBSERVATIONS INDICATE THESE
CLOUDS WILL DISSIPATE AS THE HIGH TRACKS EAST AS EVIDENCED BY THE
VERY DRY AIR LOCATED OVER THE WESTERN GREAT LAKES ASSOCIATED WITH
THE HIGH.

DESPITE CLEARING SKIES DURING THE AFTERNOON HOURS...SUNSHINE WILL
NOT BE ENOUGH TO MAKE UP FOR THE VERY COLD AIRMASS AND SHALLOW
MIXING DEPTHS IN PLACE ACROSS THE AREA. THESE CONDITIONS LOOK TO
LIMIT HIGH TEMPERATURES TO AROUND 60 DEGREES THIS AFTERNOON.
ALTHOUGH CLEAR SKIES AND LIGHT WINDS WILL PROVIDE IDEAL RADIATING
CONDITIONS TONIGHT WITH THE HIGH JUST TO OUR SOUTH...THE AREA WILL
ALREADY BE RECOVERING FROM THE SHOT OF COLD AIR AS 850 MB
TEMPERATURES IMPROVE TO AROUND 10 DEGREES DURING THE OVERNIGHT
HOURS. STILL...LOW TEMPERATURES LOOK TO BOTTOM OUT IN THE MIDDLE 40S
ACROSS MUCH OF THE AREA.

&&

.LONG TERM...

A PROLONGED PERIOD OF UPPER RIDGING IS POISED TO TAKE HOLD OF THE
GREAT LAKES REGION RESULTING IN AN EXTENDED PERIOD OF MOSTLY SUNNY
SKIES...TEMPERATURES IN THE 70S...AND DRY WEATHER. THE COOLEST DAY OF
THE LONG TERM PERIOD WILL BE THE FIRST. TUESDAY WILL BE
CHARACTERIZED BY A REBOUNDING THERMAL FIELD AS TODAY`S THERMAL
TROUGH EXITS EAST. UPPER RIDGING WILL BUILD IN THROUGH THE DAY,
BEING NUDGED EAST BY THE EASTWARD PROGRESSION OF THE GREAT BASIN
CLOSED LOW. H85 TEMPS WILL EVENTUALLY APPROACH 12C BY 00Z WED, BUT
IT WILL BE TOO LITTLE TOO LATE AS FAR AS MIXING GOES. AS A RESULT,
HIGHS WILL BARELY TOUCH 70 IN MOST SPOTS.

THE REMAINDER OF THE LONG TERM WILL BE BAROTROPIC IN CHARACTER BUT
STRONGLY CAPPED. A PIECE OF THE CLOSED LOW WILL SHEAR EAST AS IT IS
ABSORBED BACK INTO THE PREVAILING WESTERLIES ON WEDNESDAY AFTERNOON.
THIS WILL OCCUR OVER THE WESTERN GREAT LAKES AND WILL BE OF NO
CONSEQUENCE LOCALLY OTHER THAN A FEW MID/HIGH CLOUDS THURSDAY. THE
REMAINDER OF THAT LOW WILL CUT BACK TO THE WEST...BEST ILLUSTRATED BY
THE 0.6 PVU SURFACE AT 500MB...AS IT WORKS IN CONCERT WITH THE
DEEPENING WEST COAST TROUGH TO FORCE A WAVE BREAK OVER THE CONUS.
THE RESULTANT CUTOFF RIDGE WILL SETTLE OVER THE GREAT LAKES FOR THE
WEEKEND...ENSURING CONTINUED CAPPING. THIS RIDGE WILL CARRY WITH IT
LITTLE IN THE WAY WAY OF WARMER AIR IN THE LOW-LEVELS DESPITE
PROGGED H5 HEIGHTS UP TO 592DM OVER MICHIGAN. AS A RESULT...ONLY
MINOR TEMPERATURE MODIFICATION INTO THE UPPER 70S...PERHAPS TOUCHING
80 ON A COUPLE OF OVERACHIEVING DAYS, IS EXPECTED. WITH CLEAR SKIES
AND A LIGHT GRADIENT...MORNING LOWS SHOULD STILL HOVER NEAR NORMAL
VALUES IN THE LOW/MID 50S EACH MORNING. A COUPLE MORNINGS FEATURING
RADIATION FOG WILL ALSO BE POSSIBLE.

&&

.MARINE...

GUSTY NORTHWEST WINDS WILL BACK TO THE WEST AND EASE THROUGH THE
DAY. SUBSIDING WAVE HEIGHTS WILL SOON TO FOLLOW WHICH WILL FINALLY
ALLOW THE POSTED SMALL CRAFT ADVISORIES FOR THE NEARSHORE WATERS OF
LAKE HURON TO EXPIRE LATER TODAY. THE REMAINDER OF THE FORECAST
PERIOD WILL FEATURE LIGHT TO OCCASIONALLY MODERATE WINDS WITH NO
PRECIPITATION.

&&

.AVIATION...ISSUED 1153 PM EDT SUN SEP 21 2014

//DISCUSSION...

A DEEP LOW LEVEL INVERSION /SHOWN IN THE 00Z APX SOUNDING/ WILL
MAINTAIN STRATUS ACROSS SE MI THROUGH DAYBREAK. THE CEILINGS LOOK
TO HOVER AROUND THE 3000 FT THRESHOLD MUCH OF THE NIGHT. ONGOING
LOW LEVEL DRY AIR ADVECTION MAY ACTUALLY LIFT BASES JUST A BIT BY
DAYBREAK. A CLEARING TREND IS EXPECTED BY EARLY MON AFTERNOON AS
THE DRY AIR MIXES INTO THE CLOUD LAYER.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT TONIGHT...MEDIUM CONFIDENCE
MONDAY MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
     HURON...UNTIL 4 PM MONDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...KURIMSKI
LONG TERM....JVC
MARINE.......JVC
AVIATION.....SC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 220353
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1153 PM EDT SUN SEP 21 2014


.AVIATION...

//DISCUSSION...

A DEEP LOW LEVEL INVERSION /SHOWN IN THE 00Z APX SOUNDING/ WILL
MAINTAIN STRATUS ACROSS SE MI THROUGH DAYBREAK. THE CEILINGS LOOK
TO HOVER AROUND THE 3000 FT THRESHOLD MUCH OF THE NIGHT. ONGOING
LOW LEVEL DRY AIR ADVECTION MAY ACTUALLY LIFT BASES JUST A BIT BY
DAYBREAK. A CLEARING TREND IS EXPECTED BY EARLY MON AFTERNOON AS
THE DRY AIR MIXES INTO THE CLOUD LAYER.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT TONIGHT...MEDIUM CONFIDENCE
MONDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 336 PM EDT SUN SEP 21 2014

SHORT TERM...TONIGHT

UPPER LEVEL LOW/CIRCULATION PIVOTING THROUGH THE CENTRAL GREAT LAKES
THIS AFTERNOON...SUPPORTING PLENTY OF SHOWERS (CATEGORICAL) WORKING
THEIR WAY THROUGH SOUTHEAST MICHIGAN. SURFACE COLD FRONT NOW
STARTING TO SURGE SOUTHWARD THROUGH SOUTHERN LOWER MICHIGAN...AND
SHOULD MOSTLY BE OUT OF THE CWA AROUND 00Z...WITH JUST A LOW/SLIGHT
CHANCE OF SOME LEFTOVER LIGHT SHOWERS ACROSS THE FAR EASTERN
SECTION OF THE CWA FOR A COUPLE HOURS POST 00Z. THE ADDED
CONVERGENCE ALONG THE FRONT IS ENHANCING THE SHOWERS
PRESENTLY...WITH EVEN A FEW LIGHTENING STRIKES NOTED EARLIER
TOWARD SAGINAW BAY. WITH ONLY ABOUT 500 J/KG OF SURFACE BASED CAPE
TO WORK WITH...EXPECTING THUNDER ACTIVITY TO REMAIN ISOLATED. THE
12Z NAM IS ADAMANT LOW LEVEL MOISTURE WILL REMAIN TRAPPED
UNDERNEATH THE DEVELOPING SUBSIDENCE INVERSION BEHIND THE UPPER
LEVEL TROUGH AXIS OVERNIGHT...WITH CLOUDS LOCKED IN THE 2000-3000
FOOT LEVEL. THE 12Z GFS/EURO ARE DRIER...BUT STILL ENOUGH EVIDENCE
IN THE 925-850 MB LAYER TO GO WITH MORE PESSIMISTIC SKY FORECAST
TONIGHT...AS CLOUDS ARE STILL LOCKED IN NORTH OF THE GREAT LAKES
IN ONTARIO. WOULD REFER MORE NORTHERLY FLOW (VS NORTHWEST) OFF
LAKE HURON AS 850 MB TEMPS DROP TO ZERO OR SLIGHTLY COLDER TO BE
100 PERCENT CONFIDENT IN THE CLOUDS...BUT NONE-THE-LESS...HAVE
AVERAGE TO ABOVE CONFIDENCE IN MOSTLY CLOUDY SKIES PREVAILING
THROUGH THE NIGHT...WHICH SHOULD KEEP MINS ON THE PLUS SIDE OF 40
DEGREES...ABOUT 20 DEGREES COLDER COMPARED TO THIS MORNINGS LOWS.

LONG TERM...MONDAY THROUGH SUNDAY

SPRAWLING HIGH PRESSURE SYSTEM WILL BUILD INTO THE AREA MONDAY AND
BRING CLEARING SKIES. THE CANADIAN ORIGIN OF THIS HIGH WILL RESULT
IN COOL CONDTIONS WITH HIGHS IN THE LOWER 60S FOR THE MOST PART. BY
MONDAY NIGHT...RETURN SOUTHWEST FLOW IS ALREADY SETTING UP AROUND
THIS HIGH AS THE CENTER BECOMES ESTABLISHED OVER THE OHIO VALLEY.
THIS WILL HOLD LOW TEMPERATURES CLOSE TO SEASONAL AVERAGES IN THE
MIDDLE 40S. TEMPERATURES WILL CONTINUE TO MODERATE INTO TUESDAY AS
HIGH PRESSURE MOVES EAST AND COMBINES WITH ANOTHER HIGH PRESSURE
CENTER DROPPING SOUTHEAST THROUGH QUEBEC. TEMPERATURES ARE EXPECTED
TO CLIMB TO AROUND 70 ON TUESDAY UNDER MOSTLY SUNNY SKIES AND FALL
INTO THE UPPER 40S/LOWER 50S TUESDAY NIGHT AS THE QUIET CONDITIONS
PREVAIL FROM THE STRONG HIGH PRESSURE THAT EVOLVES OVER UPSTATE NEW
YORK AND THE NEW ENGLAND STATES.

FOR THE EXTENDED...SPRAWLING HIGH PRESSURE WILL EXTEND FROM THE
WESTERN ATLANTIC OCEAN TO THE OHIO VALLEY AND GREAT LAKES REGION. SE
MI WILL REMAIN UNDER THE INFLUENCE OF THIS HIGH FOR SEVERAL DAYS AS
THE UPPER LEVEL PATTERN BECOMES STAGNANT UNDER AN OMEGA BLOCKING
HIGH PATTERN. TEMPERATURES WILL BE ON THE INCREASE THROUGH THE WEEK
WITH ABOVE NORMAL VALUES EXPECTED.

MARINE...

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL END AS LOW
PRESSURE SHIFTS QUICKLY EAST OVERNIGHT. NORTHERLY FLOW IN THE WAKE
OF THIS SYSTEM WILL REMAIN GUSTY INTO TONIGHT...BEFORE SLOWLY EASING
LATE TONIGHT INTO MONDAY. EVEN AS THE FLOW SUBSIDES...WAVE ACTION
WILL BE SLOWER TO FALL SO SMALL CRAFT ADVISORIES WILL REMAIN IN
EFFECT OVER PORTIONS OF THE LAKE HURON NEARSHORE ZONES INTO MONDAY
AFTERNOON. FAVORABLE MARINE CONDITIONS THEN SET UP FOR THE REMAINDER
OF THE WEEK AS HIGH PRESSURE BECOMES ESTABLISHED OVER MUCH OF THE
NORTHEASTERN UNITED STATES.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
     HURON...UNTIL 4 PM MONDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....DG/MM
MARINE.......DG


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 220353
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1153 PM EDT SUN SEP 21 2014


.AVIATION...

//DISCUSSION...

A DEEP LOW LEVEL INVERSION /SHOWN IN THE 00Z APX SOUNDING/ WILL
MAINTAIN STRATUS ACROSS SE MI THROUGH DAYBREAK. THE CEILINGS LOOK
TO HOVER AROUND THE 3000 FT THRESHOLD MUCH OF THE NIGHT. ONGOING
LOW LEVEL DRY AIR ADVECTION MAY ACTUALLY LIFT BASES JUST A BIT BY
DAYBREAK. A CLEARING TREND IS EXPECTED BY EARLY MON AFTERNOON AS
THE DRY AIR MIXES INTO THE CLOUD LAYER.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT TONIGHT...MEDIUM CONFIDENCE
MONDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 336 PM EDT SUN SEP 21 2014

SHORT TERM...TONIGHT

UPPER LEVEL LOW/CIRCULATION PIVOTING THROUGH THE CENTRAL GREAT LAKES
THIS AFTERNOON...SUPPORTING PLENTY OF SHOWERS (CATEGORICAL) WORKING
THEIR WAY THROUGH SOUTHEAST MICHIGAN. SURFACE COLD FRONT NOW
STARTING TO SURGE SOUTHWARD THROUGH SOUTHERN LOWER MICHIGAN...AND
SHOULD MOSTLY BE OUT OF THE CWA AROUND 00Z...WITH JUST A LOW/SLIGHT
CHANCE OF SOME LEFTOVER LIGHT SHOWERS ACROSS THE FAR EASTERN
SECTION OF THE CWA FOR A COUPLE HOURS POST 00Z. THE ADDED
CONVERGENCE ALONG THE FRONT IS ENHANCING THE SHOWERS
PRESENTLY...WITH EVEN A FEW LIGHTENING STRIKES NOTED EARLIER
TOWARD SAGINAW BAY. WITH ONLY ABOUT 500 J/KG OF SURFACE BASED CAPE
TO WORK WITH...EXPECTING THUNDER ACTIVITY TO REMAIN ISOLATED. THE
12Z NAM IS ADAMANT LOW LEVEL MOISTURE WILL REMAIN TRAPPED
UNDERNEATH THE DEVELOPING SUBSIDENCE INVERSION BEHIND THE UPPER
LEVEL TROUGH AXIS OVERNIGHT...WITH CLOUDS LOCKED IN THE 2000-3000
FOOT LEVEL. THE 12Z GFS/EURO ARE DRIER...BUT STILL ENOUGH EVIDENCE
IN THE 925-850 MB LAYER TO GO WITH MORE PESSIMISTIC SKY FORECAST
TONIGHT...AS CLOUDS ARE STILL LOCKED IN NORTH OF THE GREAT LAKES
IN ONTARIO. WOULD REFER MORE NORTHERLY FLOW (VS NORTHWEST) OFF
LAKE HURON AS 850 MB TEMPS DROP TO ZERO OR SLIGHTLY COLDER TO BE
100 PERCENT CONFIDENT IN THE CLOUDS...BUT NONE-THE-LESS...HAVE
AVERAGE TO ABOVE CONFIDENCE IN MOSTLY CLOUDY SKIES PREVAILING
THROUGH THE NIGHT...WHICH SHOULD KEEP MINS ON THE PLUS SIDE OF 40
DEGREES...ABOUT 20 DEGREES COLDER COMPARED TO THIS MORNINGS LOWS.

LONG TERM...MONDAY THROUGH SUNDAY

SPRAWLING HIGH PRESSURE SYSTEM WILL BUILD INTO THE AREA MONDAY AND
BRING CLEARING SKIES. THE CANADIAN ORIGIN OF THIS HIGH WILL RESULT
IN COOL CONDTIONS WITH HIGHS IN THE LOWER 60S FOR THE MOST PART. BY
MONDAY NIGHT...RETURN SOUTHWEST FLOW IS ALREADY SETTING UP AROUND
THIS HIGH AS THE CENTER BECOMES ESTABLISHED OVER THE OHIO VALLEY.
THIS WILL HOLD LOW TEMPERATURES CLOSE TO SEASONAL AVERAGES IN THE
MIDDLE 40S. TEMPERATURES WILL CONTINUE TO MODERATE INTO TUESDAY AS
HIGH PRESSURE MOVES EAST AND COMBINES WITH ANOTHER HIGH PRESSURE
CENTER DROPPING SOUTHEAST THROUGH QUEBEC. TEMPERATURES ARE EXPECTED
TO CLIMB TO AROUND 70 ON TUESDAY UNDER MOSTLY SUNNY SKIES AND FALL
INTO THE UPPER 40S/LOWER 50S TUESDAY NIGHT AS THE QUIET CONDITIONS
PREVAIL FROM THE STRONG HIGH PRESSURE THAT EVOLVES OVER UPSTATE NEW
YORK AND THE NEW ENGLAND STATES.

FOR THE EXTENDED...SPRAWLING HIGH PRESSURE WILL EXTEND FROM THE
WESTERN ATLANTIC OCEAN TO THE OHIO VALLEY AND GREAT LAKES REGION. SE
MI WILL REMAIN UNDER THE INFLUENCE OF THIS HIGH FOR SEVERAL DAYS AS
THE UPPER LEVEL PATTERN BECOMES STAGNANT UNDER AN OMEGA BLOCKING
HIGH PATTERN. TEMPERATURES WILL BE ON THE INCREASE THROUGH THE WEEK
WITH ABOVE NORMAL VALUES EXPECTED.

MARINE...

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL END AS LOW
PRESSURE SHIFTS QUICKLY EAST OVERNIGHT. NORTHERLY FLOW IN THE WAKE
OF THIS SYSTEM WILL REMAIN GUSTY INTO TONIGHT...BEFORE SLOWLY EASING
LATE TONIGHT INTO MONDAY. EVEN AS THE FLOW SUBSIDES...WAVE ACTION
WILL BE SLOWER TO FALL SO SMALL CRAFT ADVISORIES WILL REMAIN IN
EFFECT OVER PORTIONS OF THE LAKE HURON NEARSHORE ZONES INTO MONDAY
AFTERNOON. FAVORABLE MARINE CONDITIONS THEN SET UP FOR THE REMAINDER
OF THE WEEK AS HIGH PRESSURE BECOMES ESTABLISHED OVER MUCH OF THE
NORTHEASTERN UNITED STATES.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
     HURON...UNTIL 4 PM MONDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....DG/MM
MARINE.......DG


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 212301
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
701 PM EDT SUN SEP 21 2014


.AVIATION...

//DISCUSSION...

POST FRONTAL COLD AIR ADVECTION SHOULD SUSTAIN GUSTY N-NW WINDS
THROUGH THE REST OF THE EVENING /GUSTS OVER 20 KNOTS AT TIMES/.
GRADUAL COOLING IN THE BOUNDARY LAYER LATE TONIGHT INTO MON MORNING
WILL LEAD TO A SLOW DROP IN THE WINDS AS THE NIGHT WEARS ON.
RESIDUAL LOW LEVEL MOISTURE WITHIN A DEEPENING INVERSION WILL
SUSTAIN MVFR STRATUS THROUGH THE NIGHT. THE MOISTURE DEPTH WILL
BECOME MUCH MORE SHALLOW DURING THE MORNING AS VERY DRY AIR ADVECTS
ATOP THE INVERSION. THIS MAY ALLOW SOME BREAKS IN THE
OVERCAST...ESPECIALLY CONSIDERING THE SLIGHT DOWNSLOPE FROM THE NW
FLOW. A CLEARING TREND IS EXPECTED BY EARLY MON AFTERNOON AS THE DRY
AIR MIXES INTO THE CLOUD LAYER.

FOR DTW...RESIDUAL LIGHT RAIN SHOULD END ROUGHLY BETWEEN 01 AND 02Z.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT TONIGHT...MEDIUM CONFIDENCE
MONDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 336 PM EDT SUN SEP 21 2014

SHORT TERM...TONIGHT

UPPER LEVEL LOW/CIRCULATION PIVOTING THROUGH THE CENTRAL GREAT LAKES
THIS AFTERNOON...SUPPORTING PLENTY OF SHOWERS (CATEGORICAL) WORKING
THEIR WAY THROUGH SOUTHEAST MICHIGAN. SURFACE COLD FRONT NOW
STARTING TO SURGE SOUTHWARD THROUGH SOUTHERN LOWER MICHIGAN...AND
SHOULD MOSTLY BE OUT OF THE CWA AROUND 00Z...WITH JUST A LOW/SLIGHT
CHANCE OF SOME LEFTOVER LIGHT SHOWERS ACROSS THE FAR EASTERN
SECTION OF THE CWA FOR A COUPLE HOURS POST 00Z. THE ADDED
CONVERGENCE ALONG THE FRONT IS ENHANCING THE SHOWERS
PRESENTLY...WITH EVEN A FEW LIGHTENING STRIKES NOTED EARLIER
TOWARD SAGINAW BAY. WITH ONLY ABOUT 500 J/KG OF SURFACE BASED CAPE
TO WORK WITH...EXPECTING THUNDER ACTIVITY TO REMAIN ISOLATED. THE
12Z NAM IS ADAMANT LOW LEVEL MOISTURE WILL REMAIN TRAPPED
UNDERNEATH THE DEVELOPING SUBSIDENCE INVERSION BEHIND THE UPPER
LEVEL TROUGH AXIS OVERNIGHT...WITH CLOUDS LOCKED IN THE 2000-3000
FOOT LEVEL. THE 12Z GFS/EURO ARE DRIER...BUT STILL ENOUGH EVIDENCE
IN THE 925-850 MB LAYER TO GO WITH MORE PESSIMISTIC SKY FORECAST
TONIGHT...AS CLOUDS ARE STILL LOCKED IN NORTH OF THE GREAT LAKES
IN ONTARIO. WOULD REFER MORE NORTHERLY FLOW (VS NORTHWEST) OFF
LAKE HURON AS 850 MB TEMPS DROP TO ZERO OR SLIGHTLY COLDER TO BE
100 PERCENT CONFIDENT IN THE CLOUDS...BUT NONE-THE-LESS...HAVE
AVERAGE TO ABOVE CONFIDENCE IN MOSTLY CLOUDY SKIES PREVAILING
THROUGH THE NIGHT...WHICH SHOULD KEEP MINS ON THE PLUS SIDE OF 40
DEGREES...ABOUT 20 DEGREES COLDER COMPARED TO THIS MORNINGS LOWS.

LONG TERM...MONDAY THROUGH SUNDAY

SPRAWLING HIGH PRESSURE SYSTEM WILL BUILD INTO THE AREA MONDAY AND
BRING CLEARING SKIES. THE CANADIAN ORIGIN OF THIS HIGH WILL RESULT
IN COOL CONDTIONS WITH HIGHS IN THE LOWER 60S FOR THE MOST PART. BY
MONDAY NIGHT...RETURN SOUTHWEST FLOW IS ALREADY SETTING UP AROUND
THIS HIGH AS THE CENTER BECOMES ESTABLISHED OVER THE OHIO VALLEY.
THIS WILL HOLD LOW TEMPERATURES CLOSE TO SEASONAL AVERAGES IN THE
MIDDLE 40S. TEMPERATURES WILL CONTINUE TO MODERATE INTO TUESDAY AS
HIGH PRESSURE MOVES EAST AND COMBINES WITH ANOTHER HIGH PRESSURE
CENTER DROPPING SOUTHEAST THROUGH QUEBEC. TEMPERATURES ARE EXPECTED
TO CLIMB TO AROUND 70 ON TUESDAY UNDER MOSTLY SUNNY SKIES AND FALL
INTO THE UPPER 40S/LOWER 50S TUESDAY NIGHT AS THE QUIET CONDITIONS
PREVAIL FROM THE STRONG HIGH PRESSURE THAT EVOLVES OVER UPSTATE NEW
YORK AND THE NEW ENGLAND STATES.

FOR THE EXTENDED...SPRAWLING HIGH PRESSURE WILL EXTEND FROM THE
WESTERN ATLANTIC OCEAN TO THE OHIO VALLEY AND GREAT LAKES REGION. SE
MI WILL REMAIN UNDER THE INFLUENCE OF THIS HIGH FOR SEVERAL DAYS AS
THE UPPER LEVEL PATTERN BECOMES STAGNANT UNDER AN OMEGA BLOCKING
HIGH PATTERN. TEMPERATURES WILL BE ON THE INCREASE THROUGH THE WEEK
WITH ABOVE NORMAL VALUES EXPECTED.

MARINE...

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL END AS LOW
PRESSURE SHIFTS QUICKLY EAST OVERNIGHT. NORTHERLY FLOW IN THE WAKE
OF THIS SYSTEM WILL REMAIN GUSTY INTO TONIGHT...BEFORE SLOWLY EASING
LATE TONIGHT INTO MONDAY. EVEN AS THE FLOW SUBSIDES...WAVE ACTION
WILL BE SLOWER TO FALL SO SMALL CRAFT ADVISORIES WILL REMAIN IN
EFFECT OVER PORTIONS OF THE LAKE HURON NEARSHORE ZONES INTO MONDAY
AFTERNOON. FAVORABLE MARINE CONDITIONS THEN SET UP FOR THE REMAINDER
OF THE WEEK AS HIGH PRESSURE BECOMES ESTABLISHED OVER MUCH OF THE
NORTHEASTERN UNITED STATES.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
     HURON...UNTIL 4 PM MONDAY.

LAKE ST CLAIR...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

MI WATERS OF LAKE ERIE...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....DG/MM
MARINE.......DG


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 212301
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
701 PM EDT SUN SEP 21 2014


.AVIATION...

//DISCUSSION...

POST FRONTAL COLD AIR ADVECTION SHOULD SUSTAIN GUSTY N-NW WINDS
THROUGH THE REST OF THE EVENING /GUSTS OVER 20 KNOTS AT TIMES/.
GRADUAL COOLING IN THE BOUNDARY LAYER LATE TONIGHT INTO MON MORNING
WILL LEAD TO A SLOW DROP IN THE WINDS AS THE NIGHT WEARS ON.
RESIDUAL LOW LEVEL MOISTURE WITHIN A DEEPENING INVERSION WILL
SUSTAIN MVFR STRATUS THROUGH THE NIGHT. THE MOISTURE DEPTH WILL
BECOME MUCH MORE SHALLOW DURING THE MORNING AS VERY DRY AIR ADVECTS
ATOP THE INVERSION. THIS MAY ALLOW SOME BREAKS IN THE
OVERCAST...ESPECIALLY CONSIDERING THE SLIGHT DOWNSLOPE FROM THE NW
FLOW. A CLEARING TREND IS EXPECTED BY EARLY MON AFTERNOON AS THE DRY
AIR MIXES INTO THE CLOUD LAYER.

FOR DTW...RESIDUAL LIGHT RAIN SHOULD END ROUGHLY BETWEEN 01 AND 02Z.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT TONIGHT...MEDIUM CONFIDENCE
MONDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 336 PM EDT SUN SEP 21 2014

SHORT TERM...TONIGHT

UPPER LEVEL LOW/CIRCULATION PIVOTING THROUGH THE CENTRAL GREAT LAKES
THIS AFTERNOON...SUPPORTING PLENTY OF SHOWERS (CATEGORICAL) WORKING
THEIR WAY THROUGH SOUTHEAST MICHIGAN. SURFACE COLD FRONT NOW
STARTING TO SURGE SOUTHWARD THROUGH SOUTHERN LOWER MICHIGAN...AND
SHOULD MOSTLY BE OUT OF THE CWA AROUND 00Z...WITH JUST A LOW/SLIGHT
CHANCE OF SOME LEFTOVER LIGHT SHOWERS ACROSS THE FAR EASTERN
SECTION OF THE CWA FOR A COUPLE HOURS POST 00Z. THE ADDED
CONVERGENCE ALONG THE FRONT IS ENHANCING THE SHOWERS
PRESENTLY...WITH EVEN A FEW LIGHTENING STRIKES NOTED EARLIER
TOWARD SAGINAW BAY. WITH ONLY ABOUT 500 J/KG OF SURFACE BASED CAPE
TO WORK WITH...EXPECTING THUNDER ACTIVITY TO REMAIN ISOLATED. THE
12Z NAM IS ADAMANT LOW LEVEL MOISTURE WILL REMAIN TRAPPED
UNDERNEATH THE DEVELOPING SUBSIDENCE INVERSION BEHIND THE UPPER
LEVEL TROUGH AXIS OVERNIGHT...WITH CLOUDS LOCKED IN THE 2000-3000
FOOT LEVEL. THE 12Z GFS/EURO ARE DRIER...BUT STILL ENOUGH EVIDENCE
IN THE 925-850 MB LAYER TO GO WITH MORE PESSIMISTIC SKY FORECAST
TONIGHT...AS CLOUDS ARE STILL LOCKED IN NORTH OF THE GREAT LAKES
IN ONTARIO. WOULD REFER MORE NORTHERLY FLOW (VS NORTHWEST) OFF
LAKE HURON AS 850 MB TEMPS DROP TO ZERO OR SLIGHTLY COLDER TO BE
100 PERCENT CONFIDENT IN THE CLOUDS...BUT NONE-THE-LESS...HAVE
AVERAGE TO ABOVE CONFIDENCE IN MOSTLY CLOUDY SKIES PREVAILING
THROUGH THE NIGHT...WHICH SHOULD KEEP MINS ON THE PLUS SIDE OF 40
DEGREES...ABOUT 20 DEGREES COLDER COMPARED TO THIS MORNINGS LOWS.

LONG TERM...MONDAY THROUGH SUNDAY

SPRAWLING HIGH PRESSURE SYSTEM WILL BUILD INTO THE AREA MONDAY AND
BRING CLEARING SKIES. THE CANADIAN ORIGIN OF THIS HIGH WILL RESULT
IN COOL CONDTIONS WITH HIGHS IN THE LOWER 60S FOR THE MOST PART. BY
MONDAY NIGHT...RETURN SOUTHWEST FLOW IS ALREADY SETTING UP AROUND
THIS HIGH AS THE CENTER BECOMES ESTABLISHED OVER THE OHIO VALLEY.
THIS WILL HOLD LOW TEMPERATURES CLOSE TO SEASONAL AVERAGES IN THE
MIDDLE 40S. TEMPERATURES WILL CONTINUE TO MODERATE INTO TUESDAY AS
HIGH PRESSURE MOVES EAST AND COMBINES WITH ANOTHER HIGH PRESSURE
CENTER DROPPING SOUTHEAST THROUGH QUEBEC. TEMPERATURES ARE EXPECTED
TO CLIMB TO AROUND 70 ON TUESDAY UNDER MOSTLY SUNNY SKIES AND FALL
INTO THE UPPER 40S/LOWER 50S TUESDAY NIGHT AS THE QUIET CONDITIONS
PREVAIL FROM THE STRONG HIGH PRESSURE THAT EVOLVES OVER UPSTATE NEW
YORK AND THE NEW ENGLAND STATES.

FOR THE EXTENDED...SPRAWLING HIGH PRESSURE WILL EXTEND FROM THE
WESTERN ATLANTIC OCEAN TO THE OHIO VALLEY AND GREAT LAKES REGION. SE
MI WILL REMAIN UNDER THE INFLUENCE OF THIS HIGH FOR SEVERAL DAYS AS
THE UPPER LEVEL PATTERN BECOMES STAGNANT UNDER AN OMEGA BLOCKING
HIGH PATTERN. TEMPERATURES WILL BE ON THE INCREASE THROUGH THE WEEK
WITH ABOVE NORMAL VALUES EXPECTED.

MARINE...

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL END AS LOW
PRESSURE SHIFTS QUICKLY EAST OVERNIGHT. NORTHERLY FLOW IN THE WAKE
OF THIS SYSTEM WILL REMAIN GUSTY INTO TONIGHT...BEFORE SLOWLY EASING
LATE TONIGHT INTO MONDAY. EVEN AS THE FLOW SUBSIDES...WAVE ACTION
WILL BE SLOWER TO FALL SO SMALL CRAFT ADVISORIES WILL REMAIN IN
EFFECT OVER PORTIONS OF THE LAKE HURON NEARSHORE ZONES INTO MONDAY
AFTERNOON. FAVORABLE MARINE CONDITIONS THEN SET UP FOR THE REMAINDER
OF THE WEEK AS HIGH PRESSURE BECOMES ESTABLISHED OVER MUCH OF THE
NORTHEASTERN UNITED STATES.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
     HURON...UNTIL 4 PM MONDAY.

LAKE ST CLAIR...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

MI WATERS OF LAKE ERIE...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....DG/MM
MARINE.......DG


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 211936
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
336 PM EDT SUN SEP 21 2014

.SHORT TERM...TONIGHT

UPPER LEVEL LOW/CIRCULATION PIVOTING THROUGH THE CENTRAL GREAT LAKES
THIS AFTERNOON...SUPPORTING PLENTY OF SHOWERS (CATEGORICAL) WORKING
THEIR WAY THROUGH SOUTHEAST MICHIGAN. SURFACE COLD FRONT NOW
STARTING TO SURGE SOUTHWARD THROUGH SOUTHERN LOWER MICHIGAN...AND
SHOULD MOSTLY BE OUT OF THE CWA AROUND 00Z...WITH JUST A LOW/SLIGHT
CHANCE OF SOME LEFTOVER LIGHT SHOWERS ACROSS THE FAR EASTERN
SECTION OF THE CWA FOR A COUPLE HOURS POST 00Z. THE ADDED
CONVERGENCE ALONG THE FRONT IS ENHANCING THE SHOWERS
PRESENTLY...WITH EVEN A FEW LIGHTENING STRIKES NOTED EARLIER
TOWARD SAGINAW BAY. WITH ONLY ABOUT 500 J/KG OF SURFACE BASED CAPE
TO WORK WITH...EXPECTING THUNDER ACTIVITY TO REMAIN ISOLATED. THE
12Z NAM IS ADAMANT LOW LEVEL MOISTURE WILL REMAIN TRAPPED
UNDERNEATH THE DEVELOPING SUBSIDENCE INVERSION BEHIND THE UPPER
LEVEL TROUGH AXIS OVERNIGHT...WITH CLOUDS LOCKED IN THE 2000-3000
FOOT LEVEL. THE 12Z GFS/EURO ARE DRIER...BUT STILL ENOUGH EVIDENCE
IN THE 925-850 MB LAYER TO GO WITH MORE PESSIMISTIC SKY FORECAST
TONIGHT...AS CLOUDS ARE STILL LOCKED IN NORTH OF THE GREAT LAKES
IN ONTARIO. WOULD REFER MORE NORTHERLY FLOW (VS NORTHWEST) OFF
LAKE HURON AS 850 MB TEMPS DROP TO ZERO OR SLIGHTLY COLDER TO BE
100 PERCENT CONFIDENT IN THE CLOUDS...BUT NONE-THE-LESS...HAVE
AVERAGE TO ABOVE CONFIDENCE IN MOSTLY CLOUDY SKIES PREVAILING
THROUGH THE NIGHT...WHICH SHOULD KEEP MINS ON THE PLUS SIDE OF 40
DEGREES...ABOUT 20 DEGREES COLDER COMPARED TO THIS MORNINGS LOWS.

&&

.LONG TERM...MONDAY THROUGH SUNDAY

SPRAWLING HIGH PRESSURE SYSTEM WILL BUILD INTO THE AREA MONDAY AND
BRING CLEARING SKIES. THE CANADIAN ORIGIN OF THIS HIGH WILL RESULT
IN COOL CONDTIONS WITH HIGHS IN THE LOWER 60S FOR THE MOST PART. BY
MONDAY NIGHT...RETURN SOUTHWEST FLOW IS ALREADY SETTING UP AROUND
THIS HIGH AS THE CENTER BECOMES ESTABLISHED OVER THE OHIO VALLEY.
THIS WILL HOLD LOW TEMPERATURES CLOSE TO SEASONAL AVERAGES IN THE
MIDDLE 40S. TEMPERATURES WILL CONTINUE TO MODERATE INTO TUESDAY AS
HIGH PRESSURE MOVES EAST AND COMBINES WITH ANOTHER HIGH PRESSURE
CENTER DROPPING SOUTHEAST THROUGH QUEBEC. TEMPERATURES ARE EXPECTED
TO CLIMB TO AROUND 70 ON TUESDAY UNDER MOSTLY SUNNY SKIES AND FALL
INTO THE UPPER 40S/LOWER 50S TUESDAY NIGHT AS THE QUIET CONDITIONS
PREVAIL FROM THE STRONG HIGH PRESSURE THAT EVOLVES OVER UPSTATE NEW
YORK AND THE NEW ENGLAND STATES.

FOR THE EXTENDED...SPRAWLING HIGH PRESSURE WILL EXTEND FROM THE
WESTERN ATLANTIC OCEAN TO THE OHIO VALLEY AND GREAT LAKES REGION. SE
MI WILL REMAIN UNDER THE INFLUENCE OF THIS HIGH FOR SEVERAL DAYS AS
THE UPPER LEVEL PATTERN BECOMES STAGNANT UNDER AN OMEGA BLOCKING
HIGH PATTERN. TEMPERATURES WILL BE ON THE INCREASE THROUGH THE WEEK
WITH ABOVE NORMAL VALUES EXPECTED.

&&

.MARINE...

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL END AS LOW
PRESSURE SHIFTS QUICKLY EAST OVERNIGHT. NORTHERLY FLOW IN THE WAKE
OF THIS SYSTEM WILL REMAIN GUSTY INTO TONIGHT...BEFORE SLOWLY EASING
LATE TONIGHT INTO MONDAY. EVEN AS THE FLOW SUBSIDES...WAVE ACTION
WILL BE SLOWER TO FALL SO SMALL CRAFT ADVISORIES WILL REMAIN IN
EFFECT OVER PORTIONS OF THE LAKE HURON NEARSHORE ZONES INTO MONDAY
AFTERNOON. FAVORABLE MARINE CONDITIONS THEN SET UP FOR THE REMAINDER
OF THE WEEK AS HIGH PRESSURE BECOMES ESTABLISHED OVER MUCH OF THE
NORTHEASTERN UNITED STATES.

&&

.AVIATION...ISSUED 103 PM EDT SUN SEP 21 2014

//DISCUSSION...

MVFR SHOWERS WILL BE MOVING THROUGH SOUTHEAST MICHIGAN THIS
AFTERNOON...AND TAPER OFF TOWARD EVENING. THERE IS A SLIGHT CHANCE OF
THUNDER...BUT CHANCES ARE TOO LOW TO INCLUDE IN TAFS. WESTERLY
WINDS GUSTING AROUND 25 KNOTS WILL BE DIMINISHING SOME AS THEY
COME AROUND TO THE NORTHWEST TO NORTH BY EVENING. ONCE THE SHOWERS
END...IT IS EXPECTED THERE WILL BE ENOUGH LOW LEVEL MOISTURE
TRAPPED UNDERNEATH THE DEVELOPING SUBSIDENCE INVERSION TO MAINTAIN
MVFR CEILINGS OVERNIGHT INTO TOMORROW MORNING...BEFORE CIGS SLOWLY
RISE AND MIX OUT DURING THE DAYTIME HOURS OF MONDAY.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT THROUGH THE EVENING...MEDIUM
CONFIDENCE OVERNIGHT INTO MONDAY MORNING.

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW THIS AFTERNOON

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
     HURON...UNTIL 4 PM MONDAY.

LAKE ST CLAIR...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

MI WATERS OF LAKE ERIE...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

&&

$$

SHORT TERM...SF
LONG TERM....DG/MM
MARINE.......DG
AVIATION.....SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 211936
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
336 PM EDT SUN SEP 21 2014

.SHORT TERM...TONIGHT

UPPER LEVEL LOW/CIRCULATION PIVOTING THROUGH THE CENTRAL GREAT LAKES
THIS AFTERNOON...SUPPORTING PLENTY OF SHOWERS (CATEGORICAL) WORKING
THEIR WAY THROUGH SOUTHEAST MICHIGAN. SURFACE COLD FRONT NOW
STARTING TO SURGE SOUTHWARD THROUGH SOUTHERN LOWER MICHIGAN...AND
SHOULD MOSTLY BE OUT OF THE CWA AROUND 00Z...WITH JUST A LOW/SLIGHT
CHANCE OF SOME LEFTOVER LIGHT SHOWERS ACROSS THE FAR EASTERN
SECTION OF THE CWA FOR A COUPLE HOURS POST 00Z. THE ADDED
CONVERGENCE ALONG THE FRONT IS ENHANCING THE SHOWERS
PRESENTLY...WITH EVEN A FEW LIGHTENING STRIKES NOTED EARLIER
TOWARD SAGINAW BAY. WITH ONLY ABOUT 500 J/KG OF SURFACE BASED CAPE
TO WORK WITH...EXPECTING THUNDER ACTIVITY TO REMAIN ISOLATED. THE
12Z NAM IS ADAMANT LOW LEVEL MOISTURE WILL REMAIN TRAPPED
UNDERNEATH THE DEVELOPING SUBSIDENCE INVERSION BEHIND THE UPPER
LEVEL TROUGH AXIS OVERNIGHT...WITH CLOUDS LOCKED IN THE 2000-3000
FOOT LEVEL. THE 12Z GFS/EURO ARE DRIER...BUT STILL ENOUGH EVIDENCE
IN THE 925-850 MB LAYER TO GO WITH MORE PESSIMISTIC SKY FORECAST
TONIGHT...AS CLOUDS ARE STILL LOCKED IN NORTH OF THE GREAT LAKES
IN ONTARIO. WOULD REFER MORE NORTHERLY FLOW (VS NORTHWEST) OFF
LAKE HURON AS 850 MB TEMPS DROP TO ZERO OR SLIGHTLY COLDER TO BE
100 PERCENT CONFIDENT IN THE CLOUDS...BUT NONE-THE-LESS...HAVE
AVERAGE TO ABOVE CONFIDENCE IN MOSTLY CLOUDY SKIES PREVAILING
THROUGH THE NIGHT...WHICH SHOULD KEEP MINS ON THE PLUS SIDE OF 40
DEGREES...ABOUT 20 DEGREES COLDER COMPARED TO THIS MORNINGS LOWS.

&&

.LONG TERM...MONDAY THROUGH SUNDAY

SPRAWLING HIGH PRESSURE SYSTEM WILL BUILD INTO THE AREA MONDAY AND
BRING CLEARING SKIES. THE CANADIAN ORIGIN OF THIS HIGH WILL RESULT
IN COOL CONDTIONS WITH HIGHS IN THE LOWER 60S FOR THE MOST PART. BY
MONDAY NIGHT...RETURN SOUTHWEST FLOW IS ALREADY SETTING UP AROUND
THIS HIGH AS THE CENTER BECOMES ESTABLISHED OVER THE OHIO VALLEY.
THIS WILL HOLD LOW TEMPERATURES CLOSE TO SEASONAL AVERAGES IN THE
MIDDLE 40S. TEMPERATURES WILL CONTINUE TO MODERATE INTO TUESDAY AS
HIGH PRESSURE MOVES EAST AND COMBINES WITH ANOTHER HIGH PRESSURE
CENTER DROPPING SOUTHEAST THROUGH QUEBEC. TEMPERATURES ARE EXPECTED
TO CLIMB TO AROUND 70 ON TUESDAY UNDER MOSTLY SUNNY SKIES AND FALL
INTO THE UPPER 40S/LOWER 50S TUESDAY NIGHT AS THE QUIET CONDITIONS
PREVAIL FROM THE STRONG HIGH PRESSURE THAT EVOLVES OVER UPSTATE NEW
YORK AND THE NEW ENGLAND STATES.

FOR THE EXTENDED...SPRAWLING HIGH PRESSURE WILL EXTEND FROM THE
WESTERN ATLANTIC OCEAN TO THE OHIO VALLEY AND GREAT LAKES REGION. SE
MI WILL REMAIN UNDER THE INFLUENCE OF THIS HIGH FOR SEVERAL DAYS AS
THE UPPER LEVEL PATTERN BECOMES STAGNANT UNDER AN OMEGA BLOCKING
HIGH PATTERN. TEMPERATURES WILL BE ON THE INCREASE THROUGH THE WEEK
WITH ABOVE NORMAL VALUES EXPECTED.

&&

.MARINE...

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL END AS LOW
PRESSURE SHIFTS QUICKLY EAST OVERNIGHT. NORTHERLY FLOW IN THE WAKE
OF THIS SYSTEM WILL REMAIN GUSTY INTO TONIGHT...BEFORE SLOWLY EASING
LATE TONIGHT INTO MONDAY. EVEN AS THE FLOW SUBSIDES...WAVE ACTION
WILL BE SLOWER TO FALL SO SMALL CRAFT ADVISORIES WILL REMAIN IN
EFFECT OVER PORTIONS OF THE LAKE HURON NEARSHORE ZONES INTO MONDAY
AFTERNOON. FAVORABLE MARINE CONDITIONS THEN SET UP FOR THE REMAINDER
OF THE WEEK AS HIGH PRESSURE BECOMES ESTABLISHED OVER MUCH OF THE
NORTHEASTERN UNITED STATES.

&&

.AVIATION...ISSUED 103 PM EDT SUN SEP 21 2014

//DISCUSSION...

MVFR SHOWERS WILL BE MOVING THROUGH SOUTHEAST MICHIGAN THIS
AFTERNOON...AND TAPER OFF TOWARD EVENING. THERE IS A SLIGHT CHANCE OF
THUNDER...BUT CHANCES ARE TOO LOW TO INCLUDE IN TAFS. WESTERLY
WINDS GUSTING AROUND 25 KNOTS WILL BE DIMINISHING SOME AS THEY
COME AROUND TO THE NORTHWEST TO NORTH BY EVENING. ONCE THE SHOWERS
END...IT IS EXPECTED THERE WILL BE ENOUGH LOW LEVEL MOISTURE
TRAPPED UNDERNEATH THE DEVELOPING SUBSIDENCE INVERSION TO MAINTAIN
MVFR CEILINGS OVERNIGHT INTO TOMORROW MORNING...BEFORE CIGS SLOWLY
RISE AND MIX OUT DURING THE DAYTIME HOURS OF MONDAY.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT THROUGH THE EVENING...MEDIUM
CONFIDENCE OVERNIGHT INTO MONDAY MORNING.

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW THIS AFTERNOON

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
     HURON...UNTIL 4 PM MONDAY.

LAKE ST CLAIR...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

MI WATERS OF LAKE ERIE...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

&&

$$

SHORT TERM...SF
LONG TERM....DG/MM
MARINE.......DG
AVIATION.....SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 211703
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
103 PM EDT SUN SEP 21 2014

.AVIATION...

//DISCUSSION...

MVFR SHOWERS WILL BE MOVING THROUGH SOUTHEAST MICHIGAN THIS
AFTERNOON...AND TAPER OFF TOWARD EVENING. THERE IS A SLIGHT CHANCE OF
THUNDER...BUT CHANCES ARE TOO LOW TO INCLUDE IN TAFS. WESTERLY
WINDS GUSTING AROUND 25 KNOTS WILL BE DIMINISHING SOME AS THEY
COME AROUND TO THE NORTHWEST TO NORTH BY EVENING. ONCE THE SHOWERS
END...IT IS EXPECTED THERE WILL BE ENOUGH LOW LEVEL MOISTURE
TRAPPED UNDERNEATH THE DEVELOPING SUBSIDENCE INVERSION TO MAINTAIN
MVFR CEILINGS OVERNIGHT INTO TOMORROW MORNING...BEFORE CIGS SLOWLY
RISE AND MIX OUT DURING THE DAYTIME HOURS OF MONDAY.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT THROUGH THE EVENING...MEDIUM
CONFIDENCE OVERNIGHT INTO MONDAY MORNING.

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW THIS AFTERNOON

&&

.PREV DISCUSSION...ISSUED 308 AM EDT SUN SEP 21 2014

SHORT TERM...TODAY AND TONIGHT

CONVECTION IS ONGOING ALONG THE LEAD EDGE OF A STRONG PV ANOMALY
THAT IS PROPAGATING ACROSS THE WESTERN GREAT LAKES EARLY THIS
MORNING. ANOTHER FOCUS OF ACTIVITY IS ONGOING WITHIN THE LOW-LEVEL
THETA-E THAT SUPPORTED LAST NIGHT`S THUNDERSTORM ACTIVITY. RENEWED
COVERAGE AND INTENSITY IS OBSERVED AS HEIGHT FALLS ASSOCIATED WITH
THE UPSTREAM ANOMALY SPREAD INTO THE AREA AND SWLY 300-310K SYSTEM
RELATIVE ISENTROPIC ASCENT RAMPS UP. YET A THIRD FOCUS OF CONVECTION
IS ONGOING ALONG A SURFACE COLD FRONT OVER NORTHERN LOWER MICHIGAN.
THE THERMAL STRUCTURE IN PLACE TODAY IS CORRESPONDINGLY CONVOLUTED
AND DIFFICULT TO DIAGNOSE.

08-12Z IS THE TARGET PERIOD FOR THE FIRST TWO FOCI OF ACTIVITY BASED
ON HIGH RESOLUTION MODEL GUIDANCE AND THE LATEST OBSERVATIONAL TRENDS.
DURING THIS TIME, STEEPER LAPSE RATES WILL BE MAKING INROADS INTO
THE REGION SUPPORTING MARGINAL ELEVATED INSTABILITY OF AROUND 800
J/KG AND SHEAR IN THE EFFECTIVE LAYER IN EXCESS OF 50 KNOTS. THIS
WILL PROVIDE SOME OPPORTUNITY FOR STORM ORGANIZATION AND A LOW END
SEVERE WIND/HAIL THREAT FIRST THING THIS MORNING. THE THREAT SHOULD
REMAIN RATHER LIMITED, HOWEVER, GIVEN MARGINAL INSTABILITY, THE FACT
THAT BETTER LAPSE RATES WILL STILL BE LARGELY LAGGING BEHIND, AND A
MID-LEVEL WIND REGIME THAT MAY SIMPLY BE TOO STRONG FOR UPDRAFTS TO
SURVIVE IN. A BREAK WILL THEN ENSUE DURING MID-MORNING AS THE BETTER
FORCING QUICKLY RACES EAST AND THE BETTER MOISTURE REMAINS TIED TO
THE FRONT OVER NORTHERN LOWER.

MOISTURE CONVERGENCE ALONG THE MID-LEVEL TROUGH AXIS WILL ROTATE
INTO THE AREA FROM THE NORTHWEST DURING THE LATE MORNING AND EARLY
AFTERNOON WHILE THE ASSOCIATED HEIGHT FALLS HELP EASE THE NORTHERN
COLD FRONT SOUTH INTO THE AREA. AT THE SAME TIME, THE TRAILING SHEAR
MAX WILL PIVOT ACROSS THE AREA BRINGING RENEWED LARGE SCALE ASCENT
AND H6-H3 DEFORMATION FORCING. WITH THE THETA-E AXIS HAVING BEEN
SHUNTED EAST FAR EARLIER IN THE DAY, SEVERE PROSPECTS WILL BE
MINIMAL. HOWEVER, H7-H5 LAPSE RATES NEAR 7/C SUPPORTED BY H5 TEMPS
OF -19C WILL SUPPORT TYPICAL COLD INSTABILITY SHOWERS CAPABLE OF
PRODUCING SMALL HAIL AND GUSTY WINDS. MOISTURE AXIS AND DEFORMATION
WILL PIVOT OUT OF THE AREA 00-03Z BRINGING AN END TO SHOWERS.

COLD ADVECTION FROM THE SOUTHWEST IN THE WAKE OF THIS MORNING`S
INITIAL WAVE WILL GIVE WAY TO A STRONGER SHOT OF NWLY COLD ADVECTION
LATER THIS AFTERNOON INTO TONIGHT. A STRONG SIGNAL FOR SYSTEM
RELATIVE ISENTROPIC DESCENT IS OBSERVED ON THE 290K SURFACE, WHICH
SUGGESTS HEALTHY DYNAMIC SUPPORT FOR TRANSPORT OF WINDS UP TO 25KT
WINDS TO THE SURFACE. IT WILL BE NEARLY A WASH AGAINST RELATIVELY
STRONG SEPTEMBER INSOLATION, BUT THE SHOT OF CAA MAY BE SUFFICIENT
TO RESULT IN FALLING TEMPS ACROSS THE NORTHERN HALF OF THE CWA
DURING THE AFTERNOON, ESPECIALLY IN THE THUMB. COLD ADVECTION WILL
WANE A BIT DURING THE OVERNIGHT HOURS, BUT THE BOUNDARY LAYER WILL
REMAIN SUFFICIENTLY WELL-MIXED TO SUPPORT WINDS OF 5-10KTS. HEALTHY
MOISTURE FLUX OFF OF THE LAKES WILL SUPPORT WIDESPREAD STRATOCU.
LOWS WILL BOTTOM OUT IN THE UPPER 30S TO MID 40S.

LONG TERM...MONDAY THROUGH SATURDAY.

A SLUG OF COLD AIR WILL MARCH SOUTHWARD ON MONDAY...KEEPING HIGH
TEMPERATURES AROUND 60 DEGREES DURING THE DAYTIME HOURS. THE COLD
AIR ADVECTING SOUTH OVER THE COOL WATER WILL LIKELY LEAD TO
CLOUDS...ESPECIALLY OVER THE THUMB WHERE NORTH NORTHWESTERLY FLOW
CAN PICK UP MOISTURE OFF LAKE HURON. THESE CLOUDS WILL SLOWLY ERODE
FROM WEST TO EAST MONDAY AFTERNOON AS DRIER AIR WORKS ITS WAY IN
FROM THE WEST AND WINDS TURN WESTERLY...STOPPING THE FEED OF
MOISTURE OFF LAKE HURON. THE CLEARING OUT WILL ALLOW MONDAY NIGHT
MINIMUMS TO PLUMMET INTO THE 40S.

HIGH PRESSURE WILL BUILD IN OVER THE SOUTHERN OHIO VALLEY ON
TUESDAY...THEN BUILD EAST OVER THE EASTERN GREAT LAKES AND THE
EASTERN SEABOARD BY THE MIDDLE OF THE WEEK. THIS HIGH WILL STICK
AROUND THROUGH THE REST OF THE WEEK AS AN OMEGA BLOCKING HIGH SETS
UP ACROSS THE EASTERN HALF OF THE CONUS KEEPING THE WEATHER DRY
THROUGH THE REST OF THE EXTENDED. ALTHOUGH WE WILL BE IN A BLOCKING
PATTERN...TEMPERATURES WILL MODERATE BY THE MIDDLE PART OF THE
WEEK...WITH HIGHS GETTING BACK INTO THE 70S BY THE END OF THE WEEK.

MARINE...

A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO ADDITIONAL
SHOWERS AND THUNDERSTORMS TODAY. BRISK NORTHERLY WINDS OF 20 TO 25
KNOTS WILL FOLLOW THIS FRONT THIS AFTERNOON...ALLOWING LARGE WAVE TO
BUILD OVER SOUTHERN LAKE HURON TONIGHT. THIS WILL LEAD TO SMALL
CRAFT ADVISORY CONDITIONS ACROSS ALL OF THE LAKE HURON NEARSHORE
WATERS AS WELL AS OUTER SAGINAW BAY THIS AFTERNOON AND TONIGHT.
THEREFORE WILL ISSUE SMALL CRAFT ADVISORIES FOR THIS TIME FRAME.
HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS STARTING
TUESDAY...AND CONTINUING THROUGH THE MIDDLE OF NEXT WEEK.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
     HURON...UNTIL 4 PM MONDAY.

LAKE ST CLAIR...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

MI WATERS OF LAKE ERIE...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

&&

$$

AVIATION.....SF
SHORT TERM...JVC
LONG TERM....KURIMSKI
MARINE.......KURIMSKI


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 211703
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
103 PM EDT SUN SEP 21 2014

.AVIATION...

//DISCUSSION...

MVFR SHOWERS WILL BE MOVING THROUGH SOUTHEAST MICHIGAN THIS
AFTERNOON...AND TAPER OFF TOWARD EVENING. THERE IS A SLIGHT CHANCE OF
THUNDER...BUT CHANCES ARE TOO LOW TO INCLUDE IN TAFS. WESTERLY
WINDS GUSTING AROUND 25 KNOTS WILL BE DIMINISHING SOME AS THEY
COME AROUND TO THE NORTHWEST TO NORTH BY EVENING. ONCE THE SHOWERS
END...IT IS EXPECTED THERE WILL BE ENOUGH LOW LEVEL MOISTURE
TRAPPED UNDERNEATH THE DEVELOPING SUBSIDENCE INVERSION TO MAINTAIN
MVFR CEILINGS OVERNIGHT INTO TOMORROW MORNING...BEFORE CIGS SLOWLY
RISE AND MIX OUT DURING THE DAYTIME HOURS OF MONDAY.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT THROUGH THE EVENING...MEDIUM
CONFIDENCE OVERNIGHT INTO MONDAY MORNING.

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW THIS AFTERNOON

&&

.PREV DISCUSSION...ISSUED 308 AM EDT SUN SEP 21 2014

SHORT TERM...TODAY AND TONIGHT

CONVECTION IS ONGOING ALONG THE LEAD EDGE OF A STRONG PV ANOMALY
THAT IS PROPAGATING ACROSS THE WESTERN GREAT LAKES EARLY THIS
MORNING. ANOTHER FOCUS OF ACTIVITY IS ONGOING WITHIN THE LOW-LEVEL
THETA-E THAT SUPPORTED LAST NIGHT`S THUNDERSTORM ACTIVITY. RENEWED
COVERAGE AND INTENSITY IS OBSERVED AS HEIGHT FALLS ASSOCIATED WITH
THE UPSTREAM ANOMALY SPREAD INTO THE AREA AND SWLY 300-310K SYSTEM
RELATIVE ISENTROPIC ASCENT RAMPS UP. YET A THIRD FOCUS OF CONVECTION
IS ONGOING ALONG A SURFACE COLD FRONT OVER NORTHERN LOWER MICHIGAN.
THE THERMAL STRUCTURE IN PLACE TODAY IS CORRESPONDINGLY CONVOLUTED
AND DIFFICULT TO DIAGNOSE.

08-12Z IS THE TARGET PERIOD FOR THE FIRST TWO FOCI OF ACTIVITY BASED
ON HIGH RESOLUTION MODEL GUIDANCE AND THE LATEST OBSERVATIONAL TRENDS.
DURING THIS TIME, STEEPER LAPSE RATES WILL BE MAKING INROADS INTO
THE REGION SUPPORTING MARGINAL ELEVATED INSTABILITY OF AROUND 800
J/KG AND SHEAR IN THE EFFECTIVE LAYER IN EXCESS OF 50 KNOTS. THIS
WILL PROVIDE SOME OPPORTUNITY FOR STORM ORGANIZATION AND A LOW END
SEVERE WIND/HAIL THREAT FIRST THING THIS MORNING. THE THREAT SHOULD
REMAIN RATHER LIMITED, HOWEVER, GIVEN MARGINAL INSTABILITY, THE FACT
THAT BETTER LAPSE RATES WILL STILL BE LARGELY LAGGING BEHIND, AND A
MID-LEVEL WIND REGIME THAT MAY SIMPLY BE TOO STRONG FOR UPDRAFTS TO
SURVIVE IN. A BREAK WILL THEN ENSUE DURING MID-MORNING AS THE BETTER
FORCING QUICKLY RACES EAST AND THE BETTER MOISTURE REMAINS TIED TO
THE FRONT OVER NORTHERN LOWER.

MOISTURE CONVERGENCE ALONG THE MID-LEVEL TROUGH AXIS WILL ROTATE
INTO THE AREA FROM THE NORTHWEST DURING THE LATE MORNING AND EARLY
AFTERNOON WHILE THE ASSOCIATED HEIGHT FALLS HELP EASE THE NORTHERN
COLD FRONT SOUTH INTO THE AREA. AT THE SAME TIME, THE TRAILING SHEAR
MAX WILL PIVOT ACROSS THE AREA BRINGING RENEWED LARGE SCALE ASCENT
AND H6-H3 DEFORMATION FORCING. WITH THE THETA-E AXIS HAVING BEEN
SHUNTED EAST FAR EARLIER IN THE DAY, SEVERE PROSPECTS WILL BE
MINIMAL. HOWEVER, H7-H5 LAPSE RATES NEAR 7/C SUPPORTED BY H5 TEMPS
OF -19C WILL SUPPORT TYPICAL COLD INSTABILITY SHOWERS CAPABLE OF
PRODUCING SMALL HAIL AND GUSTY WINDS. MOISTURE AXIS AND DEFORMATION
WILL PIVOT OUT OF THE AREA 00-03Z BRINGING AN END TO SHOWERS.

COLD ADVECTION FROM THE SOUTHWEST IN THE WAKE OF THIS MORNING`S
INITIAL WAVE WILL GIVE WAY TO A STRONGER SHOT OF NWLY COLD ADVECTION
LATER THIS AFTERNOON INTO TONIGHT. A STRONG SIGNAL FOR SYSTEM
RELATIVE ISENTROPIC DESCENT IS OBSERVED ON THE 290K SURFACE, WHICH
SUGGESTS HEALTHY DYNAMIC SUPPORT FOR TRANSPORT OF WINDS UP TO 25KT
WINDS TO THE SURFACE. IT WILL BE NEARLY A WASH AGAINST RELATIVELY
STRONG SEPTEMBER INSOLATION, BUT THE SHOT OF CAA MAY BE SUFFICIENT
TO RESULT IN FALLING TEMPS ACROSS THE NORTHERN HALF OF THE CWA
DURING THE AFTERNOON, ESPECIALLY IN THE THUMB. COLD ADVECTION WILL
WANE A BIT DURING THE OVERNIGHT HOURS, BUT THE BOUNDARY LAYER WILL
REMAIN SUFFICIENTLY WELL-MIXED TO SUPPORT WINDS OF 5-10KTS. HEALTHY
MOISTURE FLUX OFF OF THE LAKES WILL SUPPORT WIDESPREAD STRATOCU.
LOWS WILL BOTTOM OUT IN THE UPPER 30S TO MID 40S.

LONG TERM...MONDAY THROUGH SATURDAY.

A SLUG OF COLD AIR WILL MARCH SOUTHWARD ON MONDAY...KEEPING HIGH
TEMPERATURES AROUND 60 DEGREES DURING THE DAYTIME HOURS. THE COLD
AIR ADVECTING SOUTH OVER THE COOL WATER WILL LIKELY LEAD TO
CLOUDS...ESPECIALLY OVER THE THUMB WHERE NORTH NORTHWESTERLY FLOW
CAN PICK UP MOISTURE OFF LAKE HURON. THESE CLOUDS WILL SLOWLY ERODE
FROM WEST TO EAST MONDAY AFTERNOON AS DRIER AIR WORKS ITS WAY IN
FROM THE WEST AND WINDS TURN WESTERLY...STOPPING THE FEED OF
MOISTURE OFF LAKE HURON. THE CLEARING OUT WILL ALLOW MONDAY NIGHT
MINIMUMS TO PLUMMET INTO THE 40S.

HIGH PRESSURE WILL BUILD IN OVER THE SOUTHERN OHIO VALLEY ON
TUESDAY...THEN BUILD EAST OVER THE EASTERN GREAT LAKES AND THE
EASTERN SEABOARD BY THE MIDDLE OF THE WEEK. THIS HIGH WILL STICK
AROUND THROUGH THE REST OF THE WEEK AS AN OMEGA BLOCKING HIGH SETS
UP ACROSS THE EASTERN HALF OF THE CONUS KEEPING THE WEATHER DRY
THROUGH THE REST OF THE EXTENDED. ALTHOUGH WE WILL BE IN A BLOCKING
PATTERN...TEMPERATURES WILL MODERATE BY THE MIDDLE PART OF THE
WEEK...WITH HIGHS GETTING BACK INTO THE 70S BY THE END OF THE WEEK.

MARINE...

A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO ADDITIONAL
SHOWERS AND THUNDERSTORMS TODAY. BRISK NORTHERLY WINDS OF 20 TO 25
KNOTS WILL FOLLOW THIS FRONT THIS AFTERNOON...ALLOWING LARGE WAVE TO
BUILD OVER SOUTHERN LAKE HURON TONIGHT. THIS WILL LEAD TO SMALL
CRAFT ADVISORY CONDITIONS ACROSS ALL OF THE LAKE HURON NEARSHORE
WATERS AS WELL AS OUTER SAGINAW BAY THIS AFTERNOON AND TONIGHT.
THEREFORE WILL ISSUE SMALL CRAFT ADVISORIES FOR THIS TIME FRAME.
HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS STARTING
TUESDAY...AND CONTINUING THROUGH THE MIDDLE OF NEXT WEEK.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
     HURON...UNTIL 4 PM MONDAY.

LAKE ST CLAIR...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

MI WATERS OF LAKE ERIE...
     SMALL CRAFT ADVISORY...UNTIL 8 PM SUNDAY.

&&

$$

AVIATION.....SF
SHORT TERM...JVC
LONG TERM....KURIMSKI
MARINE.......KURIMSKI


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 211117
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
717 AM EDT SUN SEP 21 2014


.AVIATION...

//DISCUSSION...

SATELLITE TRENDS INDICATE DRY AIR IN THE WAKE OF THIS MORNING`S
CONVECTION IS GRADUALLY FILLING IN WITH MVFR STRATUS. LOW CIGS WILL
STICK AROUND FOR THE BALANCE OF THE DAY AS BETTER MOISTURE AND
FORCING RETURNS TO THE AREA LATE THIS MORNING INTO THIS AFTN.
SCATTERED SHOWERS WILL DEVELOP THIS MORNING, FOR WHICH A TEMPO GROUP
IS IN PLACE AT MOST SITES, FOLLOWED BY MORE WIDESPREAD COVERAGE THIS
AFTN IN ASSOCIATION WITH ARRIVAL OF BETTER FORCING AND DEFORMATION.
THERE IS A SLIGHT CHANCE OF THUNDER THROUGHOUT THE DAY, BUT
INSTABILITY WILL BE LACKING AND OPTED NOT TO INCLUDE SPECIFICALLY IN
THE 12Z TAF SET. STRONG WIND FIELD WILL ALLOW FOR GUSTS IN EXCESS OF
20 KTS FOR LOCATIONS THAT CAN SUFFICIENTLY MIX PRIOR TO BETTER
COVERAGE OF SHOWERS. HOWEVER, RESERVED MORE AGGRESSIVE WIND GUST
MENTION TO APPROX 21Z-00Z PERIOD WHEN STRONGEST COLD ADVECTION
ARRIVES. CIGS WILL PERSIST BUT GRADUALLY RISE THROUGH THE NIGHT AS
CAA DEEPENS THE BOUNDARY LAYER.


//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW

&&

.PREV DISCUSSION...ISSUED 308 AM EDT SUN SEP 21 2014

SHORT TERM...TODAY AND TONIGHT

CONVECTION IS ONGOING ALONG THE LEAD EDGE OF A STRONG PV ANOMALY
THAT IS PROPAGATING ACROSS THE WESTERN GREAT LAKES EARLY THIS
MORNING. ANOTHER FOCUS OF ACTIVITY IS ONGOING WITHIN THE LOW-LEVEL
THETA-E THAT SUPPORTED LAST NIGHT`S THUNDERSTORM ACTIVITY. RENEWED
COVERAGE AND INTENSITY IS OBSERVED AS HEIGHT FALLS ASSOCIATED WITH
THE UPSTREAM ANOMALY SPREAD INTO THE AREA AND SWLY 300-310K SYSTEM
RELATIVE ISENTROPIC ASCENT RAMPS UP. YET A THIRD FOCUS OF CONVECTION
IS ONGOING ALONG A SURFACE COLD FRONT OVER NORTHERN LOWER MICHIGAN.
THE THERMAL STRUCTURE IN PLACE TODAY IS CORRESPONDINGLY CONVOLUTED
AND DIFFICULT TO DIAGNOSE.

08-12Z IS THE TARGET PERIOD FOR THE FIRST TWO FOCI OF ACTIVITY BASED
ON HIGH RESOLUTION MODEL GUIDANCE AND THE LATEST OBSERVATIONAL TRENDS.
DURING THIS TIME, STEEPER LAPSE RATES WILL BE MAKING INROADS INTO
THE REGION SUPPORTING MARGINAL ELEVATED INSTABILITY OF AROUND 800
J/KG AND SHEAR IN THE EFFECTIVE LAYER IN EXCESS OF 50 KNOTS. THIS
WILL PROVIDE SOME OPPORTUNITY FOR STORM ORGANIZATION AND A LOW END
SEVERE WIND/HAIL THREAT FIRST THING THIS MORNING. THE THREAT SHOULD
REMAIN RATHER LIMITED, HOWEVER, GIVEN MARGINAL INSTABILITY, THE FACT
THAT BETTER LAPSE RATES WILL STILL BE LARGELY LAGGING BEHIND, AND A
MID-LEVEL WIND REGIME THAT MAY SIMPLY BE TOO STRONG FOR UPDRAFTS TO
SURVIVE IN. A BREAK WILL THEN ENSUE DURING MID-MORNING AS THE BETTER
FORCING QUICKLY RACES EAST AND THE BETTER MOISTURE REMAINS TIED TO
THE FRONT OVER NORTHERN LOWER.

MOISTURE CONVERGENCE ALONG THE MID-LEVEL TROUGH AXIS WILL ROTATE
INTO THE AREA FROM THE NORTHWEST DURING THE LATE MORNING AND EARLY
AFTERNOON WHILE THE ASSOCIATED HEIGHT FALLS HELP EASE THE NORTHERN
COLD FRONT SOUTH INTO THE AREA. AT THE SAME TIME, THE TRAILING SHEAR
MAX WILL PIVOT ACROSS THE AREA BRINGING RENEWED LARGE SCALE ASCENT
AND H6-H3 DEFORMATION FORCING. WITH THE THETA-E AXIS HAVING BEEN
SHUNTED EAST FAR EARLIER IN THE DAY, SEVERE PROSPECTS WILL BE
MINIMAL. HOWEVER, H7-H5 LAPSE RATES NEAR 7/C SUPPORTED BY H5 TEMPS
OF -19C WILL SUPPORT TYPICAL COLD INSTABILITY SHOWERS CAPABLE OF
PRODUCING SMALL HAIL AND GUSTY WINDS. MOISTURE AXIS AND DEFORMATION
WILL PIVOT OUT OF THE AREA 00-03Z BRINGING AN END TO SHOWERS.

COLD ADVECTION FROM THE SOUTHWEST IN THE WAKE OF THIS MORNING`S
INITIAL WAVE WILL GIVE WAY TO A STRONGER SHOT OF NWLY COLD ADVECTION
LATER THIS AFTERNOON INTO TONIGHT. A STRONG SIGNAL FOR SYSTEM
RELATIVE ISENTROPIC DESCENT IS OBSERVED ON THE 290K SURFACE, WHICH
SUGGESTS HEALTHY DYNAMIC SUPPORT FOR TRANSPORT OF WINDS UP TO 25KT
WINDS TO THE SURFACE. IT WILL BE NEARLY A WASH AGAINST RELATIVELY
STRONG SEPTEMBER INSOLATION, BUT THE SHOT OF CAA MAY BE SUFFICIENT
TO RESULT IN FALLING TEMPS ACROSS THE NORTHERN HALF OF THE CWA
DURING THE AFTERNOON, ESPECIALLY IN THE THUMB. COLD ADVECTION WILL
WANE A BIT DURING THE OVERNIGHT HOURS, BUT THE BOUNDARY LAYER WILL
REMAIN SUFFICIENTLY WELL-MIXED TO SUPPORT WINDS OF 5-10KTS. HEALTHY
MOISTURE FLUX OFF OF THE LAKES WILL SUPPORT WIDESPREAD STRATOCU.
LOWS WILL BOTTOM OUT IN THE UPPER 30S TO MID 40S.

LONG TERM...MONDAY THROUGH SATURDAY.

A SLUG OF COLD AIR WILL MARCH SOUTHWARD ON MONDAY...KEEPING HIGH
TEMPERATURES AROUND 60 DEGREES DURING THE DAYTIME HOURS. THE COLD
AIR ADVECTING SOUTH OVER THE COOL WATER WILL LIKELY LEAD TO
CLOUDS...ESPECIALLY OVER THE THUMB WHERE NORTH NORTHWESTERLY FLOW
CAN PICK UP MOISTURE OFF LAKE HURON. THESE CLOUDS WILL SLOWLY ERODE
FROM WEST TO EAST MONDAY AFTERNOON AS DRIER AIR WORKS ITS WAY IN
FROM THE WEST AND WINDS TURN WESTERLY...STOPPING THE FEED OF
MOISTURE OFF LAKE HURON. THE CLEARING OUT WILL ALLOW MONDAY NIGHT
MINIMUMS TO PLUMMET INTO THE 40S.

HIGH PRESSURE WILL BUILD IN OVER THE SOUTHERN OHIO VALLEY ON
TUESDAY...THEN BUILD EAST OVER THE EASTERN GREAT LAKES AND THE
EASTERN SEABOARD BY THE MIDDLE OF THE WEEK. THIS HIGH WILL STICK
AROUND THROUGH THE REST OF THE WEEK AS AN OMEGA BLOCKING HIGH SETS
UP ACROSS THE EASTERN HALF OF THE CONUS KEEPING THE WEATHER DRY
THROUGH THE REST OF THE EXTENDED. ALTHOUGH WE WILL BE IN A BLOCKING
PATTERN...TEMPERATURES WILL MODERATE BY THE MIDDLE PART OF THE
WEEK...WITH HIGHS GETTING BACK INTO THE 70S BY THE END OF THE WEEK.

MARINE...

A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO ADDITIONAL
SHOWERS AND THUNDERSTORMS TODAY. BRISK NORTHERLY WINDS OF 20 TO 25
KNOTS WILL FOLLOW THIS FRONT THIS AFTERNOON...ALLOWING LARGE WAVE TO
BUILD OVER SOUTHERN LAKE HURON TONIGHT. THIS WILL LEAD TO SMALL
CRAFT ADVISORY CONDITIONS ACROSS ALL OF THE LAKE HURON NEARSHORE
WATERS AS WELL AS OUTER SAGINAW BAY THIS AFTERNOON AND TONIGHT.
THEREFORE WILL ISSUE SMALL CRAFT ADVISORIES FOR THIS TIME FRAME.
HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS STARTING
TUESDAY...AND CONTINUING THROUGH THE MIDDLE OF NEXT WEEK.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
     HURON INCLUDING OUTER SAGINAW BAY...FROM NOON SUNDAY TO 10 AM
     MONDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....JVC
SHORT TERM...JVC
LONG TERM....KURIMSKI
MARINE.......KURIMSKI


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 211117
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
717 AM EDT SUN SEP 21 2014


.AVIATION...

//DISCUSSION...

SATELLITE TRENDS INDICATE DRY AIR IN THE WAKE OF THIS MORNING`S
CONVECTION IS GRADUALLY FILLING IN WITH MVFR STRATUS. LOW CIGS WILL
STICK AROUND FOR THE BALANCE OF THE DAY AS BETTER MOISTURE AND
FORCING RETURNS TO THE AREA LATE THIS MORNING INTO THIS AFTN.
SCATTERED SHOWERS WILL DEVELOP THIS MORNING, FOR WHICH A TEMPO GROUP
IS IN PLACE AT MOST SITES, FOLLOWED BY MORE WIDESPREAD COVERAGE THIS
AFTN IN ASSOCIATION WITH ARRIVAL OF BETTER FORCING AND DEFORMATION.
THERE IS A SLIGHT CHANCE OF THUNDER THROUGHOUT THE DAY, BUT
INSTABILITY WILL BE LACKING AND OPTED NOT TO INCLUDE SPECIFICALLY IN
THE 12Z TAF SET. STRONG WIND FIELD WILL ALLOW FOR GUSTS IN EXCESS OF
20 KTS FOR LOCATIONS THAT CAN SUFFICIENTLY MIX PRIOR TO BETTER
COVERAGE OF SHOWERS. HOWEVER, RESERVED MORE AGGRESSIVE WIND GUST
MENTION TO APPROX 21Z-00Z PERIOD WHEN STRONGEST COLD ADVECTION
ARRIVES. CIGS WILL PERSIST BUT GRADUALLY RISE THROUGH THE NIGHT AS
CAA DEEPENS THE BOUNDARY LAYER.


//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW

&&

.PREV DISCUSSION...ISSUED 308 AM EDT SUN SEP 21 2014

SHORT TERM...TODAY AND TONIGHT

CONVECTION IS ONGOING ALONG THE LEAD EDGE OF A STRONG PV ANOMALY
THAT IS PROPAGATING ACROSS THE WESTERN GREAT LAKES EARLY THIS
MORNING. ANOTHER FOCUS OF ACTIVITY IS ONGOING WITHIN THE LOW-LEVEL
THETA-E THAT SUPPORTED LAST NIGHT`S THUNDERSTORM ACTIVITY. RENEWED
COVERAGE AND INTENSITY IS OBSERVED AS HEIGHT FALLS ASSOCIATED WITH
THE UPSTREAM ANOMALY SPREAD INTO THE AREA AND SWLY 300-310K SYSTEM
RELATIVE ISENTROPIC ASCENT RAMPS UP. YET A THIRD FOCUS OF CONVECTION
IS ONGOING ALONG A SURFACE COLD FRONT OVER NORTHERN LOWER MICHIGAN.
THE THERMAL STRUCTURE IN PLACE TODAY IS CORRESPONDINGLY CONVOLUTED
AND DIFFICULT TO DIAGNOSE.

08-12Z IS THE TARGET PERIOD FOR THE FIRST TWO FOCI OF ACTIVITY BASED
ON HIGH RESOLUTION MODEL GUIDANCE AND THE LATEST OBSERVATIONAL TRENDS.
DURING THIS TIME, STEEPER LAPSE RATES WILL BE MAKING INROADS INTO
THE REGION SUPPORTING MARGINAL ELEVATED INSTABILITY OF AROUND 800
J/KG AND SHEAR IN THE EFFECTIVE LAYER IN EXCESS OF 50 KNOTS. THIS
WILL PROVIDE SOME OPPORTUNITY FOR STORM ORGANIZATION AND A LOW END
SEVERE WIND/HAIL THREAT FIRST THING THIS MORNING. THE THREAT SHOULD
REMAIN RATHER LIMITED, HOWEVER, GIVEN MARGINAL INSTABILITY, THE FACT
THAT BETTER LAPSE RATES WILL STILL BE LARGELY LAGGING BEHIND, AND A
MID-LEVEL WIND REGIME THAT MAY SIMPLY BE TOO STRONG FOR UPDRAFTS TO
SURVIVE IN. A BREAK WILL THEN ENSUE DURING MID-MORNING AS THE BETTER
FORCING QUICKLY RACES EAST AND THE BETTER MOISTURE REMAINS TIED TO
THE FRONT OVER NORTHERN LOWER.

MOISTURE CONVERGENCE ALONG THE MID-LEVEL TROUGH AXIS WILL ROTATE
INTO THE AREA FROM THE NORTHWEST DURING THE LATE MORNING AND EARLY
AFTERNOON WHILE THE ASSOCIATED HEIGHT FALLS HELP EASE THE NORTHERN
COLD FRONT SOUTH INTO THE AREA. AT THE SAME TIME, THE TRAILING SHEAR
MAX WILL PIVOT ACROSS THE AREA BRINGING RENEWED LARGE SCALE ASCENT
AND H6-H3 DEFORMATION FORCING. WITH THE THETA-E AXIS HAVING BEEN
SHUNTED EAST FAR EARLIER IN THE DAY, SEVERE PROSPECTS WILL BE
MINIMAL. HOWEVER, H7-H5 LAPSE RATES NEAR 7/C SUPPORTED BY H5 TEMPS
OF -19C WILL SUPPORT TYPICAL COLD INSTABILITY SHOWERS CAPABLE OF
PRODUCING SMALL HAIL AND GUSTY WINDS. MOISTURE AXIS AND DEFORMATION
WILL PIVOT OUT OF THE AREA 00-03Z BRINGING AN END TO SHOWERS.

COLD ADVECTION FROM THE SOUTHWEST IN THE WAKE OF THIS MORNING`S
INITIAL WAVE WILL GIVE WAY TO A STRONGER SHOT OF NWLY COLD ADVECTION
LATER THIS AFTERNOON INTO TONIGHT. A STRONG SIGNAL FOR SYSTEM
RELATIVE ISENTROPIC DESCENT IS OBSERVED ON THE 290K SURFACE, WHICH
SUGGESTS HEALTHY DYNAMIC SUPPORT FOR TRANSPORT OF WINDS UP TO 25KT
WINDS TO THE SURFACE. IT WILL BE NEARLY A WASH AGAINST RELATIVELY
STRONG SEPTEMBER INSOLATION, BUT THE SHOT OF CAA MAY BE SUFFICIENT
TO RESULT IN FALLING TEMPS ACROSS THE NORTHERN HALF OF THE CWA
DURING THE AFTERNOON, ESPECIALLY IN THE THUMB. COLD ADVECTION WILL
WANE A BIT DURING THE OVERNIGHT HOURS, BUT THE BOUNDARY LAYER WILL
REMAIN SUFFICIENTLY WELL-MIXED TO SUPPORT WINDS OF 5-10KTS. HEALTHY
MOISTURE FLUX OFF OF THE LAKES WILL SUPPORT WIDESPREAD STRATOCU.
LOWS WILL BOTTOM OUT IN THE UPPER 30S TO MID 40S.

LONG TERM...MONDAY THROUGH SATURDAY.

A SLUG OF COLD AIR WILL MARCH SOUTHWARD ON MONDAY...KEEPING HIGH
TEMPERATURES AROUND 60 DEGREES DURING THE DAYTIME HOURS. THE COLD
AIR ADVECTING SOUTH OVER THE COOL WATER WILL LIKELY LEAD TO
CLOUDS...ESPECIALLY OVER THE THUMB WHERE NORTH NORTHWESTERLY FLOW
CAN PICK UP MOISTURE OFF LAKE HURON. THESE CLOUDS WILL SLOWLY ERODE
FROM WEST TO EAST MONDAY AFTERNOON AS DRIER AIR WORKS ITS WAY IN
FROM THE WEST AND WINDS TURN WESTERLY...STOPPING THE FEED OF
MOISTURE OFF LAKE HURON. THE CLEARING OUT WILL ALLOW MONDAY NIGHT
MINIMUMS TO PLUMMET INTO THE 40S.

HIGH PRESSURE WILL BUILD IN OVER THE SOUTHERN OHIO VALLEY ON
TUESDAY...THEN BUILD EAST OVER THE EASTERN GREAT LAKES AND THE
EASTERN SEABOARD BY THE MIDDLE OF THE WEEK. THIS HIGH WILL STICK
AROUND THROUGH THE REST OF THE WEEK AS AN OMEGA BLOCKING HIGH SETS
UP ACROSS THE EASTERN HALF OF THE CONUS KEEPING THE WEATHER DRY
THROUGH THE REST OF THE EXTENDED. ALTHOUGH WE WILL BE IN A BLOCKING
PATTERN...TEMPERATURES WILL MODERATE BY THE MIDDLE PART OF THE
WEEK...WITH HIGHS GETTING BACK INTO THE 70S BY THE END OF THE WEEK.

MARINE...

A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO ADDITIONAL
SHOWERS AND THUNDERSTORMS TODAY. BRISK NORTHERLY WINDS OF 20 TO 25
KNOTS WILL FOLLOW THIS FRONT THIS AFTERNOON...ALLOWING LARGE WAVE TO
BUILD OVER SOUTHERN LAKE HURON TONIGHT. THIS WILL LEAD TO SMALL
CRAFT ADVISORY CONDITIONS ACROSS ALL OF THE LAKE HURON NEARSHORE
WATERS AS WELL AS OUTER SAGINAW BAY THIS AFTERNOON AND TONIGHT.
THEREFORE WILL ISSUE SMALL CRAFT ADVISORIES FOR THIS TIME FRAME.
HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS STARTING
TUESDAY...AND CONTINUING THROUGH THE MIDDLE OF NEXT WEEK.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
     HURON INCLUDING OUTER SAGINAW BAY...FROM NOON SUNDAY TO 10 AM
     MONDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....JVC
SHORT TERM...JVC
LONG TERM....KURIMSKI
MARINE.......KURIMSKI


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 210708
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
308 AM EDT SUN SEP 21 2014

.SHORT TERM...TODAY AND TONIGHT

CONVECTION IS ONGOING ALONG THE LEAD EDGE OF A STRONG PV ANOMALY
THAT IS PROPAGATING ACROSS THE WESTERN GREAT LAKES EARLY THIS
MORNING. ANOTHER FOCUS OF ACTIVITY IS ONGOING WITHIN THE LOW-LEVEL
THETA-E THAT SUPPORTED LAST NIGHT`S THUNDERSTORM ACTIVITY. RENEWED
COVERAGE AND INTENSITY IS OBSERVED AS HEIGHT FALLS ASSOCIATED WITH
THE UPSTREAM ANOMALY SPREAD INTO THE AREA AND SWLY 300-310K SYSTEM
RELATIVE ISENTROPIC ASCENT RAMPS UP. YET A THIRD FOCUS OF CONVECTION
IS ONGOING ALONG A SURFACE COLD FRONT OVER NORTHERN LOWER MICHIGAN.
THE THERMAL STRUCTURE IN PLACE TODAY IS CORRESPONDINGLY CONVOLUTED
AND DIFFICULT TO DIAGNOSE.

08-12Z IS THE TARGET PERIOD FOR THE FIRST TWO FOCI OF ACTIVITY BASED
ON HIGH RESOLUTION MODEL GUIDANCE AND THE LATEST OBSERVATIONAL TRENDS.
DURING THIS TIME, STEEPER LAPSE RATES WILL BE MAKING INROADS INTO
THE REGION SUPPORTING MARGINAL ELEVATED INSTABILITY OF AROUND 800
J/KG AND SHEAR IN THE EFFECTIVE LAYER IN EXCESS OF 50 KNOTS. THIS
WILL PROVIDE SOME OPPORTUNITY FOR STORM ORGANIZATION AND A LOW END
SEVERE WIND/HAIL THREAT FIRST THING THIS MORNING. THE THREAT SHOULD
REMAIN RATHER LIMITED, HOWEVER, GIVEN MARGINAL INSTABILITY, THE FACT
THAT BETTER LAPSE RATES WILL STILL BE LARGELY LAGGING BEHIND, AND A
MID-LEVEL WIND REGIME THAT MAY SIMPLY BE TOO STRONG FOR UPDRAFTS TO
SURVIVE IN. A BREAK WILL THEN ENSUE DURING MID-MORNING AS THE BETTER
FORCING QUICKLY RACES EAST AND THE BETTER MOISTURE REMAINS TIED TO
THE FRONT OVER NORTHERN LOWER.

MOISTURE CONVERGENCE ALONG THE MID-LEVEL TROUGH AXIS WILL ROTATE
INTO THE AREA FROM THE NORTHWEST DURING THE LATE MORNING AND EARLY
AFTERNOON WHILE THE ASSOCIATED HEIGHT FALLS HELP EASE THE NORTHERN
COLD FRONT SOUTH INTO THE AREA. AT THE SAME TIME, THE TRAILING SHEAR
MAX WILL PIVOT ACROSS THE AREA BRINGING RENEWED LARGE SCALE ASCENT
AND H6-H3 DEFORMATION FORCING. WITH THE THETA-E AXIS HAVING BEEN
SHUNTED EAST FAR EARLIER IN THE DAY, SEVERE PROSPECTS WILL BE
MINIMAL. HOWEVER, H7-H5 LAPSE RATES NEAR 7/C SUPPORTED BY H5 TEMPS
OF -19C WILL SUPPORT TYPICAL COLD INSTABILITY SHOWERS CAPABLE OF
PRODUCING SMALL HAIL AND GUSTY WINDS. MOISTURE AXIS AND DEFORMATION
WILL PIVOT OUT OF THE AREA 00-03Z BRINGING AN END TO SHOWERS.

COLD ADVECTION FROM THE SOUTHWEST IN THE WAKE OF THIS MORNING`S
INITIAL WAVE WILL GIVE WAY TO A STRONGER SHOT OF NWLY COLD ADVECTION
LATER THIS AFTERNOON INTO TONIGHT. A STRONG SIGNAL FOR SYSTEM
RELATIVE ISENTROPIC DESCENT IS OBSERVED ON THE 290K SURFACE, WHICH
SUGGESTS HEALTHY DYNAMIC SUPPORT FOR TRANSPORT OF WINDS UP TO 25KT
WINDS TO THE SURFACE. IT WILL BE NEARLY A WASH AGAINST RELATIVELY
STRONG SEPTEMBER INSOLATION, BUT THE SHOT OF CAA MAY BE SUFFICIENT
TO RESULT IN FALLING TEMPS ACROSS THE NORTHERN HALF OF THE CWA
DURING THE AFTERNOON, ESPECIALLY IN THE THUMB. COLD ADVECTION WILL
WANE A BIT DURING THE OVERNIGHT HOURS, BUT THE BOUNDARY LAYER WILL
REMAIN SUFFICIENTLY WELL-MIXED TO SUPPORT WINDS OF 5-10KTS. HEALTHY
MOISTURE FLUX OFF OF THE LAKES WILL SUPPORT WIDESPREAD STRATOCU.
LOWS WILL BOTTOM OUT IN THE UPPER 30S TO MID 40S.

&&

.LONG TERM...MONDAY THROUGH SATURDAY.

A SLUG OF COLD AIR WILL MARCH SOUTHWARD ON MONDAY...KEEPING HIGH
TEMPERATURES AROUND 60 DEGREES DURING THE DAYTIME HOURS. THE COLD
AIR ADVECTING SOUTH OVER THE COOL WATER WILL LIKELY LEAD TO
CLOUDS...ESPECIALLY OVER THE THUMB WHERE NORTH NORTHWESTERLY FLOW
CAN PICK UP MOISTURE OFF LAKE HURON. THESE CLOUDS WILL SLOWLY ERODE
FROM WEST TO EAST MONDAY AFTERNOON AS DRIER AIR WORKS ITS WAY IN
FROM THE WEST AND WINDS TURN WESTERLY...STOPPING THE FEED OF
MOISTURE OFF LAKE HURON. THE CLEARING OUT WILL ALLOW MONDAY NIGHT
MINIMUMS TO PLUMMET INTO THE 40S.

HIGH PRESSURE WILL BUILD IN OVER THE SOUTHERN OHIO VALLEY ON
TUESDAY...THEN BUILD EAST OVER THE EASTERN GREAT LAKES AND THE
EASTERN SEABOARD BY THE MIDDLE OF THE WEEK. THIS HIGH WILL STICK
AROUND THROUGH THE REST OF THE WEEK AS AN OMEGA BLOCKING HIGH SETS
UP ACROSS THE EASTERN HALF OF THE CONUS KEEPING THE WEATHER DRY
THROUGH THE REST OF THE EXTENDED. ALTHOUGH WE WILL BE IN A BLOCKING
PATTERN...TEMPERATURES WILL MODERATE BY THE MIDDLE PART OF THE
WEEK...WITH HIGHS GETTING BACK INTO THE 70S BY THE END OF THE WEEK.

&&

.MARINE...

A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO ADDITIONAL
SHOWERS AND THUNDERSTORMS TODAY. BRISK NORTHERLY WINDS OF 20 TO 25
KNOTS WILL FOLLOW THIS FRONT THIS AFTERNOON...ALLOWING LARGE WAVE TO
BUILD OVER SOUTHERN LAKE HURON TONIGHT. THIS WILL LEAD TO SMALL
CRAFT ADVISORY CONDITIONS ACROSS ALL OF THE LAKE HURON NEARSHORE
WATERS AS WELL AS OUTER SAGINAW BAY THIS AFTERNOON AND TONIGHT.
THEREFORE WILL ISSUE SMALL CRAFT ADVISORIES FOR THIS TIME FRAME.
HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS STARTING
TUESDAY...AND CONTINUING THROUGH THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...ISSUED 1151 PM EDT SAT SEP 20 2014

//DISCUSSION...

A GRADUAL EXPANSION OF IFR STRATUS HAS BEEN OCCURRING IN THE WAKE OF
THE EVENING STORMS. LOW LEVEL MOISTURE AND A DEVELOPING INVERSION
SHOULD CAUSE CONTINUED LOW STRATUS DEVELOPMENT INTO THE MORNING.
ANOTHER UPPER LOW RAPIDLY APPROACHING FROM THE WEST AND A RENEWED
SURGE OF INSTABILITY WILL LEAD TO INCREASING CHANCES FOR
THUNDERSTORMS DURING THE MORNING INTO EARLY AFTERNOON. ALTHOUGH
THERE WILL BE A GOOD CHANCE FOR STORMS ANYTIME AFTER 09Z...THE MOST
PROBABLE TIME PERIOD WILL BE AHEAD OF THE COLD FRONT. THE FRONT WILL
ENTER MBS BY 12Z...BUT WILL LIKELY SLOW AS IT WORKS ACROSS METRO
DETROIT LATE MORNING AND EARLY AFTERNOON AS THE UPPER WAVE SLOWS.

FOR DTW...

THERE CERTAINLY IS A POTENTIAL FOR STORMS TO LIFT UP FROM THE
SOUTH AND IMPACT METRO EARLY THIS MORNING. CHANCES OF THIS ARE
QUITE LOW ATTM. THE BEST INSTABILITY AND LOW LEVEL CONVERGENCE
WILL OCCUR DURING THE AFTERNOON.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE CEILINGS WILL BE BELOW 5000 FT THROUGH THE TAF
PERIOD.

* MEDIUM CONFIDENCE ON THUNDERSTORMS SUN MORNING AND SUN
  AFTERNOON.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...JVC
LONG TERM....KURIMSKI
MARINE.......KURIMSKI
AVIATION.....SC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 210708
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
308 AM EDT SUN SEP 21 2014

.SHORT TERM...TODAY AND TONIGHT

CONVECTION IS ONGOING ALONG THE LEAD EDGE OF A STRONG PV ANOMALY
THAT IS PROPAGATING ACROSS THE WESTERN GREAT LAKES EARLY THIS
MORNING. ANOTHER FOCUS OF ACTIVITY IS ONGOING WITHIN THE LOW-LEVEL
THETA-E THAT SUPPORTED LAST NIGHT`S THUNDERSTORM ACTIVITY. RENEWED
COVERAGE AND INTENSITY IS OBSERVED AS HEIGHT FALLS ASSOCIATED WITH
THE UPSTREAM ANOMALY SPREAD INTO THE AREA AND SWLY 300-310K SYSTEM
RELATIVE ISENTROPIC ASCENT RAMPS UP. YET A THIRD FOCUS OF CONVECTION
IS ONGOING ALONG A SURFACE COLD FRONT OVER NORTHERN LOWER MICHIGAN.
THE THERMAL STRUCTURE IN PLACE TODAY IS CORRESPONDINGLY CONVOLUTED
AND DIFFICULT TO DIAGNOSE.

08-12Z IS THE TARGET PERIOD FOR THE FIRST TWO FOCI OF ACTIVITY BASED
ON HIGH RESOLUTION MODEL GUIDANCE AND THE LATEST OBSERVATIONAL TRENDS.
DURING THIS TIME, STEEPER LAPSE RATES WILL BE MAKING INROADS INTO
THE REGION SUPPORTING MARGINAL ELEVATED INSTABILITY OF AROUND 800
J/KG AND SHEAR IN THE EFFECTIVE LAYER IN EXCESS OF 50 KNOTS. THIS
WILL PROVIDE SOME OPPORTUNITY FOR STORM ORGANIZATION AND A LOW END
SEVERE WIND/HAIL THREAT FIRST THING THIS MORNING. THE THREAT SHOULD
REMAIN RATHER LIMITED, HOWEVER, GIVEN MARGINAL INSTABILITY, THE FACT
THAT BETTER LAPSE RATES WILL STILL BE LARGELY LAGGING BEHIND, AND A
MID-LEVEL WIND REGIME THAT MAY SIMPLY BE TOO STRONG FOR UPDRAFTS TO
SURVIVE IN. A BREAK WILL THEN ENSUE DURING MID-MORNING AS THE BETTER
FORCING QUICKLY RACES EAST AND THE BETTER MOISTURE REMAINS TIED TO
THE FRONT OVER NORTHERN LOWER.

MOISTURE CONVERGENCE ALONG THE MID-LEVEL TROUGH AXIS WILL ROTATE
INTO THE AREA FROM THE NORTHWEST DURING THE LATE MORNING AND EARLY
AFTERNOON WHILE THE ASSOCIATED HEIGHT FALLS HELP EASE THE NORTHERN
COLD FRONT SOUTH INTO THE AREA. AT THE SAME TIME, THE TRAILING SHEAR
MAX WILL PIVOT ACROSS THE AREA BRINGING RENEWED LARGE SCALE ASCENT
AND H6-H3 DEFORMATION FORCING. WITH THE THETA-E AXIS HAVING BEEN
SHUNTED EAST FAR EARLIER IN THE DAY, SEVERE PROSPECTS WILL BE
MINIMAL. HOWEVER, H7-H5 LAPSE RATES NEAR 7/C SUPPORTED BY H5 TEMPS
OF -19C WILL SUPPORT TYPICAL COLD INSTABILITY SHOWERS CAPABLE OF
PRODUCING SMALL HAIL AND GUSTY WINDS. MOISTURE AXIS AND DEFORMATION
WILL PIVOT OUT OF THE AREA 00-03Z BRINGING AN END TO SHOWERS.

COLD ADVECTION FROM THE SOUTHWEST IN THE WAKE OF THIS MORNING`S
INITIAL WAVE WILL GIVE WAY TO A STRONGER SHOT OF NWLY COLD ADVECTION
LATER THIS AFTERNOON INTO TONIGHT. A STRONG SIGNAL FOR SYSTEM
RELATIVE ISENTROPIC DESCENT IS OBSERVED ON THE 290K SURFACE, WHICH
SUGGESTS HEALTHY DYNAMIC SUPPORT FOR TRANSPORT OF WINDS UP TO 25KT
WINDS TO THE SURFACE. IT WILL BE NEARLY A WASH AGAINST RELATIVELY
STRONG SEPTEMBER INSOLATION, BUT THE SHOT OF CAA MAY BE SUFFICIENT
TO RESULT IN FALLING TEMPS ACROSS THE NORTHERN HALF OF THE CWA
DURING THE AFTERNOON, ESPECIALLY IN THE THUMB. COLD ADVECTION WILL
WANE A BIT DURING THE OVERNIGHT HOURS, BUT THE BOUNDARY LAYER WILL
REMAIN SUFFICIENTLY WELL-MIXED TO SUPPORT WINDS OF 5-10KTS. HEALTHY
MOISTURE FLUX OFF OF THE LAKES WILL SUPPORT WIDESPREAD STRATOCU.
LOWS WILL BOTTOM OUT IN THE UPPER 30S TO MID 40S.

&&

.LONG TERM...MONDAY THROUGH SATURDAY.

A SLUG OF COLD AIR WILL MARCH SOUTHWARD ON MONDAY...KEEPING HIGH
TEMPERATURES AROUND 60 DEGREES DURING THE DAYTIME HOURS. THE COLD
AIR ADVECTING SOUTH OVER THE COOL WATER WILL LIKELY LEAD TO
CLOUDS...ESPECIALLY OVER THE THUMB WHERE NORTH NORTHWESTERLY FLOW
CAN PICK UP MOISTURE OFF LAKE HURON. THESE CLOUDS WILL SLOWLY ERODE
FROM WEST TO EAST MONDAY AFTERNOON AS DRIER AIR WORKS ITS WAY IN
FROM THE WEST AND WINDS TURN WESTERLY...STOPPING THE FEED OF
MOISTURE OFF LAKE HURON. THE CLEARING OUT WILL ALLOW MONDAY NIGHT
MINIMUMS TO PLUMMET INTO THE 40S.

HIGH PRESSURE WILL BUILD IN OVER THE SOUTHERN OHIO VALLEY ON
TUESDAY...THEN BUILD EAST OVER THE EASTERN GREAT LAKES AND THE
EASTERN SEABOARD BY THE MIDDLE OF THE WEEK. THIS HIGH WILL STICK
AROUND THROUGH THE REST OF THE WEEK AS AN OMEGA BLOCKING HIGH SETS
UP ACROSS THE EASTERN HALF OF THE CONUS KEEPING THE WEATHER DRY
THROUGH THE REST OF THE EXTENDED. ALTHOUGH WE WILL BE IN A BLOCKING
PATTERN...TEMPERATURES WILL MODERATE BY THE MIDDLE PART OF THE
WEEK...WITH HIGHS GETTING BACK INTO THE 70S BY THE END OF THE WEEK.

&&

.MARINE...

A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO ADDITIONAL
SHOWERS AND THUNDERSTORMS TODAY. BRISK NORTHERLY WINDS OF 20 TO 25
KNOTS WILL FOLLOW THIS FRONT THIS AFTERNOON...ALLOWING LARGE WAVE TO
BUILD OVER SOUTHERN LAKE HURON TONIGHT. THIS WILL LEAD TO SMALL
CRAFT ADVISORY CONDITIONS ACROSS ALL OF THE LAKE HURON NEARSHORE
WATERS AS WELL AS OUTER SAGINAW BAY THIS AFTERNOON AND TONIGHT.
THEREFORE WILL ISSUE SMALL CRAFT ADVISORIES FOR THIS TIME FRAME.
HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS STARTING
TUESDAY...AND CONTINUING THROUGH THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...ISSUED 1151 PM EDT SAT SEP 20 2014

//DISCUSSION...

A GRADUAL EXPANSION OF IFR STRATUS HAS BEEN OCCURRING IN THE WAKE OF
THE EVENING STORMS. LOW LEVEL MOISTURE AND A DEVELOPING INVERSION
SHOULD CAUSE CONTINUED LOW STRATUS DEVELOPMENT INTO THE MORNING.
ANOTHER UPPER LOW RAPIDLY APPROACHING FROM THE WEST AND A RENEWED
SURGE OF INSTABILITY WILL LEAD TO INCREASING CHANCES FOR
THUNDERSTORMS DURING THE MORNING INTO EARLY AFTERNOON. ALTHOUGH
THERE WILL BE A GOOD CHANCE FOR STORMS ANYTIME AFTER 09Z...THE MOST
PROBABLE TIME PERIOD WILL BE AHEAD OF THE COLD FRONT. THE FRONT WILL
ENTER MBS BY 12Z...BUT WILL LIKELY SLOW AS IT WORKS ACROSS METRO
DETROIT LATE MORNING AND EARLY AFTERNOON AS THE UPPER WAVE SLOWS.

FOR DTW...

THERE CERTAINLY IS A POTENTIAL FOR STORMS TO LIFT UP FROM THE
SOUTH AND IMPACT METRO EARLY THIS MORNING. CHANCES OF THIS ARE
QUITE LOW ATTM. THE BEST INSTABILITY AND LOW LEVEL CONVERGENCE
WILL OCCUR DURING THE AFTERNOON.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE CEILINGS WILL BE BELOW 5000 FT THROUGH THE TAF
PERIOD.

* MEDIUM CONFIDENCE ON THUNDERSTORMS SUN MORNING AND SUN
  AFTERNOON.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...JVC
LONG TERM....KURIMSKI
MARINE.......KURIMSKI
AVIATION.....SC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 210351
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1151 PM EDT SAT SEP 20 2014


.AVIATION...

//DISCUSSION...

A GRADUAL EXPANSION OF IFR STRATUS HAS BEEN OCCURRING IN THE WAKE OF
THE EVENING STORMS. LOW LEVEL MOISTURE AND A DEVELOPING INVERSION
SHOULD CAUSE CONTINUED LOW STRATUS DEVELOPMENT INTO THE MORNING.
ANOTHER UPPER LOW RAPIDLY APPROACHING FROM THE WEST AND A RENEWED
SURGE OF INSTABILITY WILL LEAD TO INCREASING CHANCES FOR
THUNDERSTORMS DURING THE MORNING INTO EARLY AFTERNOON. ALTHOUGH
THERE WILL BE A GOOD CHANCE FOR STORMS ANYTIME AFTER 09Z...THE MOST
PROBABLE TIME PERIOD WILL BE AHEAD OF THE COLD FRONT. THE FRONT WILL
ENTER MBS BY 12Z...BUT WILL LIKELY SLOW AS IT WORKS ACROSS METRO
DETROIT LATE MORNING AND EARLY AFTERNOON AS THE UPPER WAVE SLOWS.

FOR DTW...

THERE CERTAINLY IS A POTENTIAL FOR STORMS TO LIFT UP FROM THE
SOUTH AND IMPACT METRO EARLY THIS MORNING. CHANCES OF THIS ARE
QUITE LOW ATTM. THE BEST INSTABILITY AND LOW LEVEL CONVERGENCE
WILL OCCUR DURING THE AFTERNOON.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE CEILINGS WILL BE BELOW 5000 FT THROUGH THE TAF
PERIOD.

* MEDIUM CONFIDENCE ON THUNDERSTORMS SUN MORNING AND SUN
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 913 PM EDT SAT SEP 20 2014

UPDATE...

STRONG MID LEVEL SUBSIDENCE NOW OVERSPREADING SE MI IN THE WAKE OF
THE EARLIER CONVECTIVE ACTIVITY WILL SUPPRESS ADDITIONAL SHRA/TSTM
DEVELOPMENT FOR THE REST OF THE EVENING AND FIRST HALF OF THE
OVERNIGHT. THERE HAS BEEN CONVECTIVE DEVELOPMENT ALONG A COLD
FRONT OVER NORTHERN LOWER MI. THIS FRONT WILL PUSH ACROSS THE
SAGINAW VALLEY AND THUMB REGION LATE TONIGHT INTO EARLY SUN
MORNING. THE 00Z GRB SOUNDING SHOWED FAIRLY STEEP MID LEVEL LAPSE
RATES...SUPPORTING GOOD ELEVATED INSTABILITY. THE SECONDARY MID
LEVEL WAVE NOW TRAVERSING MN THIS EVENING WILL PROVIDE ANOTHER
ROUND OF LARGE SCALE ASCENT LATE TONIGHT INTO SUN MORNING. COOLING
ALOFT ASSOCIATED WITH THIS WAVE WILL IN TURN STEEPEN THE MID LEVEL
LAPSE RATES OVER SE MI. THUS ADDITIONAL CONVECTION IS POSSIBLE
LATE ACROSS THE NORTH HALF OF THE FORECAST AREA WITH THE APPROACH
OF THE FRONT. THE CHANCES FOR SHRA/TSTM WILL THEN INCREASE FURTHOR
SOUTH SUNDAY MORNING INTO AFTERNOON AS THE FRONT PUSHES THROUGH
AND THE UPPER WAVE PASSES OVERHEAD. AN UPDATED FORECAST PACKAGE
REFLECTING THIS WILL BE FORTHCOMING.

PREV DISCUSSION...ISSUED 314 PM EDT SAT SEP 20 2014

SHORT TERM...THIS AFTERNOON AND TONIGHT

SEVERAL OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION WELL TO THE
WEST ARE TRACKING ACROSS LOWER MICHIGAN. HOWEVER...18Z DTX SOUNDING
SHOWS A RATHER ROBUST CAP IN THE 875-850MB AREA...WHICH WILL LIKELY
TAKE QUITE SOME TIME TO TOTALLY ERODE. MODELS...INCLUDING PRIMARY
AND PARALLEL HRRR RUNS TODAY...SUGGEST CONVECTION WILL EVENTUALLY
FILL IN ALONG BOTH OUTFLOW BOUNDARY SINKING SOUTH/SOUTHEAST THROUGH
THE CWA AND ALSO ALONG VORTICITY SPOKE FURTHER WEST ASSOCIATED WITH
LEFTOVER WEAK MCV. GIVEN CAPPING...AND THE LACK OF SIGNIFICANT
INSTABILITY...EXPECT THIS ACTIVITY TO REMAIN RATHER DISORGANIZED AND
SUB-SEVERE FOR THE MOST PART.

WILL STILL WATCH FOR THE POTENTIAL OF A FEW SEVERE STORMS AS WIND
FIELDS ARE DECENT...INCREASING FROM 25-30 KNOTS H85-H7 TO 50 KNOTS
AT H5. WITH ADDITIONAL HEATING...TEMPERATURES AROUND 80F DETROIT
SOUTH...OVER THE SOUTHERN CWA AND A LACK OF NOTABLE DEEP LOW LEVEL
MOISTURE...INVERTED-V SOUNDINGS MAY ASSIST IN GUST POTENTIAL GIVEN
THE ABOVE ATMOSPHERIC WIND SPEEDS.

THIS INITIAL PUSH OF FORCING...AND WHATEVER CONVECTION COMES OF
IT...WILL SHIFT EAST/SOUTHEAST OF THE AREA LATE THIS AFTERNOON/EARLY
THIS EVENING. HOWEVER...HIGHER THETA-E AIR WILL CONTINUE TO SHIFT
OVER THE CWA...PARTICULARLY M 59 SOUTH...WITHIN SOUTHWEST FLOW IN
ADVANCE OF MAIN SHORTWAVE TROUGH AXIS. SO...ADDITIONAL SCATTERED
SHOWERS/EMBEDDED STORMS WILL BUILD THROUGH AREA INTO THIS EVENING.
ONCE THIS ACTIVITY EBBS LATE THIS EVENING...EXPECT RENEWED SHOWER
AND STORM DEVELOPMENT LATE TONIGHT AS MAIN UPPER LEVEL SHORTWAVE
DIGS FROM THE UPPER MISSISSIPPI VALLEY INTO THE CENTRAL GREAT LAKES.

WITH MILD...SOUTHWEST FLOW PERSISTING THROUGH THE NIGHT...MINIMUM
TEMPERATURES WILL BE RATHER MILD...HOLDING IN THE 60S IN MOST
LOCATIONS...ESPECIALLY AS FURTHER CLOUDS/PRECIPITATION PROVIDE
ADDITIONAL INSOLATION AND MINIMIZE RADIATIONAL COOLING FURTHER.

LONG TERM...

LATEST WATER VAPOR IMAGERY SHOWS A STRONG BUT PROGRESSIVE UPPER
LEVEL SYSTEM/CIRCULATION OVER SOUTHERN MANITOBA...WITH A STRONGER
EMBEDDED UPPER WAVE AT THE BASE OF THE TROUGH OVER NORTH DAKOTA. IT
IS THIS UPPER WAVE/COLD POOL (-18 TO -19 C) WHICH WILL ARRIVE OVER
SOUTHERN LOWER MICHIGAN SUNDAY MORNING. WITH SOME LEFTOVER LOW LEVEL
MOISTURE AND MORE THAN ADEQUATE MID LEVEL LAPSE RATE (6.5+ C/KM FROM
700-500 MB)...ADDITIONAL SHOWERS AND EMBEDDED THUNDERSTORMS APPEAR
LIKELY DURING SUNDAY. A SECONDARY UPPER WAVE/COLD POOL WILL FOLLOW
ON THE BACKSIDE THROUGH THE WESTERN GREAT LAKES AND INTO THE OHIO
VALLEY. DEEP NORTHERLY FLOW IN THIS SYSTEMS WAKE OVER THE CENTRAL
GREAT LAKES WILL ALLOW FOR SOLID COLD ADVECTION TO TAKE PLACE...AS
850 MB TEMPS LOWER INTO THE LOW SINGLE NUMBERS...WITH SLIGHTLY
NEGATIVE VALUES OVER LAKE HURON...PER 12Z EURO/NAM. AS SUCH...FULLY
ONBOARD WITH THE 12Z NAM 925 MB RH/LOW CLOUDS AS NORTHERLY FLOW
COMES OFF THE RELATIVELY WARM WATERS OF LAKE HURON SUNDAY NIGHT.
HAVE SUBSEQUENTLY RAMPED UP THE CLOUDS MONDAY MORNING...WHICH WILL
LIKELY TAKE MUCH OF THE DAY TO MIX OUT/ERODE...HOLDING MAXES CLOSE
TO 60 DEGREES. FAVORABLE RADIATING CONDITIONS MONDAY NIGHT EXPECTED
TO ALLOW MINS TO FALL INTO THE 40S.

STUBBORN HIGH PRESSURE AND RELENTLESS LOW RH VALUES THROUGH THE
COLUMN WILL REMAIN IN PLACE FOR THE ENTIRE EXTENDED PERIOD. FLOW
WILL CONTINUE TO BE WEAK UNDER AN OMEGA BLOCKING HIGH. TEMPERATURES
WILL TREND SLIGHTLY ABOVE NORMAL WITH NO THREAT OF PRECIPITATION.

MARINE...

WARMER AIRMASS AHEAD OF COLD FRONT...COUPLED WITH THE WEAKENING
PRESSURE GRADIENT AS THE FRONT APPROACHES IS TRANSLATING
TO WIND SPEEDS BELOW 25 KNOTS...AND WILL DROP THE SMALL CRAFT
ADVISORIES. HOWEVER...SHOWERS AND THUNDERSTORMS WILL LIKELY
DEVELOP...AND THUNDERSTORMS WILL BE STRONG TO POSSIBLY SEVERE INTO
TONIGHT. A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO
ADDITIONAL SHOWERS TOMORROW AND POSSIBLE THUNDERSTORMS. BRISK
NORTHERLY WINDS OF 20 TO 25 KNOTS WILL FOLLOW THIS FRONT...ALLOWING
LARGE WAVE TO BUILD OVER SOUTHERN LAKE HURON SUNDAY NIGHT INTO
MONDAY...WITH SMALL CRAFT ADVISORIES LIKELY NEED DURING THAT TIME
FRAME. HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS
DURING THE MIDDLE OF NEXT WEEK.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....SC
UPDATE.......SC
SHORT TERM...DG
LONG TERM....SF/MM
MARINE.......SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 210113
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
913 PM EDT SAT SEP 20 2014

.UPDATE...

STRONG MID LEVEL SUBSIDENCE NOW OVERSPREADING SE MI IN THE WAKE OF
THE EARLIER CONVECTIVE ACTIVITY WILL SUPPRESS ADDITIONAL SHRA/TSTM
DEVELOPMENT FOR THE REST OF THE EVENING AND FIRST HALF OF THE
OVERNIGHT. THERE HAS BEEN CONVECTIVE DEVELOPMENT ALONG A COLD
FRONT OVER NORTHERN LOWER MI. THIS FRONT WILL PUSH ACROSS THE
SAGINAW VALLEY AND THUMB REGION LATE TONIGHT INTO EARLY SUN
MORNING. THE 00Z GRB SOUNDING SHOWED FAIRLY STEEP MID LEVEL LAPSE
RATES...SUPPORTING GOOD ELEVATED INSTABILITY. THE SECONDARY MID
LEVEL WAVE NOW TRAVERSING MN THIS EVENING WILL PROVIDE ANOTHER
ROUND OF LARGE SCALE ASCENT LATE TONIGHT INTO SUN MORNING. COOLING
ALOFT ASSOCIATED WITH THIS WAVE WILL IN TURN STEEPEN THE MID LEVEL
LAPSE RATES OVER SE MI. THUS ADDITIONAL CONVECTION IS POSSIBLE
LATE ACROSS THE NORTH HALF OF THE FORECAST AREA WITH THE APPROACH
OF THE FRONT. THE CHANCES FOR SHRA/TSTM WILL THEN INCREASE FURTHOR
SOUTH SUNDAY MORNING INTO AFTERNOON AS THE FRONT PUSHES THROUGH
AND THE UPPER WAVE PASSES OVERHEAD. AN UPDATED FORECAST PACKAGE
REFLECTING THIS WILL BE FORTHCOMING.

&&

.PREV DISCUSSION...ISSUED 314 PM EDT SAT SEP 20 2014

SHORT TERM...THIS AFTERNOON AND TONIGHT

SEVERAL OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION WELL TO THE
WEST ARE TRACKING ACROSS LOWER MICHIGAN. HOWEVER...18Z DTX SOUNDING
SHOWS A RATHER ROBUST CAP IN THE 875-850MB AREA...WHICH WILL LIKELY
TAKE QUITE SOME TIME TO TOTALLY ERODE. MODELS...INCLUDING PRIMARY
AND PARALLEL HRRR RUNS TODAY...SUGGEST CONVECTION WILL EVENTUALLY
FILL IN ALONG BOTH OUTFLOW BOUNDARY SINKING SOUTH/SOUTHEAST THROUGH
THE CWA AND ALSO ALONG VORTICITY SPOKE FURTHER WEST ASSOCIATED WITH
LEFTOVER WEAK MCV. GIVEN CAPPING...AND THE LACK OF SIGNIFICANT
INSTABILITY...EXPECT THIS ACTIVITY TO REMAIN RATHER DISORGANIZED AND
SUB-SEVERE FOR THE MOST PART.

WILL STILL WATCH FOR THE POTENTIAL OF A FEW SEVERE STORMS AS WIND
FIELDS ARE DECENT...INCREASING FROM 25-30 KNOTS H85-H7 TO 50 KNOTS
AT H5. WITH ADDITIONAL HEATING...TEMPERATURES AROUND 80F DETROIT
SOUTH...OVER THE SOUTHERN CWA AND A LACK OF NOTABLE DEEP LOW LEVEL
MOISTURE...INVERTED-V SOUNDINGS MAY ASSIST IN GUST POTENTIAL GIVEN
THE ABOVE ATMOSPHERIC WIND SPEEDS.

THIS INITIAL PUSH OF FORCING...AND WHATEVER CONVECTION COMES OF
IT...WILL SHIFT EAST/SOUTHEAST OF THE AREA LATE THIS AFTERNOON/EARLY
THIS EVENING. HOWEVER...HIGHER THETA-E AIR WILL CONTINUE TO SHIFT
OVER THE CWA...PARTICULARLY M 59 SOUTH...WITHIN SOUTHWEST FLOW IN
ADVANCE OF MAIN SHORTWAVE TROUGH AXIS. SO...ADDITIONAL SCATTERED
SHOWERS/EMBEDDED STORMS WILL BUILD THROUGH AREA INTO THIS EVENING.
ONCE THIS ACTIVITY EBBS LATE THIS EVENING...EXPECT RENEWED SHOWER
AND STORM DEVELOPMENT LATE TONIGHT AS MAIN UPPER LEVEL SHORTWAVE
DIGS FROM THE UPPER MISSISSIPPI VALLEY INTO THE CENTRAL GREAT LAKES.

WITH MILD...SOUTHWEST FLOW PERSISTING THROUGH THE NIGHT...MINIMUM
TEMPERATURES WILL BE RATHER MILD...HOLDING IN THE 60S IN MOST
LOCATIONS...ESPECIALLY AS FURTHER CLOUDS/PRECIPITATION PROVIDE
ADDITIONAL INSOLATION AND MINIMIZE RADIATIONAL COOLING FURTHER.

LONG TERM...

LATEST WATER VAPOR IMAGERY SHOWS A STRONG BUT PROGRESSIVE UPPER
LEVEL SYSTEM/CIRCULATION OVER SOUTHERN MANITOBA...WITH A STRONGER
EMBEDDED UPPER WAVE AT THE BASE OF THE TROUGH OVER NORTH DAKOTA. IT
IS THIS UPPER WAVE/COLD POOL (-18 TO -19 C) WHICH WILL ARRIVE OVER
SOUTHERN LOWER MICHIGAN SUNDAY MORNING. WITH SOME LEFTOVER LOW LEVEL
MOISTURE AND MORE THAN ADEQUATE MID LEVEL LAPSE RATE (6.5+ C/KM FROM
700-500 MB)...ADDITIONAL SHOWERS AND EMBEDDED THUNDERSTORMS APPEAR
LIKELY DURING SUNDAY. A SECONDARY UPPER WAVE/COLD POOL WILL FOLLOW
ON THE BACKSIDE THROUGH THE WESTERN GREAT LAKES AND INTO THE OHIO
VALLEY. DEEP NORTHERLY FLOW IN THIS SYSTEMS WAKE OVER THE CENTRAL
GREAT LAKES WILL ALLOW FOR SOLID COLD ADVECTION TO TAKE PLACE...AS
850 MB TEMPS LOWER INTO THE LOW SINGLE NUMBERS...WITH SLIGHTLY
NEGATIVE VALUES OVER LAKE HURON...PER 12Z EURO/NAM. AS SUCH...FULLY
ONBOARD WITH THE 12Z NAM 925 MB RH/LOW CLOUDS AS NORTHERLY FLOW
COMES OFF THE RELATIVELY WARM WATERS OF LAKE HURON SUNDAY NIGHT.
HAVE SUBSEQUENTLY RAMPED UP THE CLOUDS MONDAY MORNING...WHICH WILL
LIKELY TAKE MUCH OF THE DAY TO MIX OUT/ERODE...HOLDING MAXES CLOSE
TO 60 DEGREES. FAVORABLE RADIATING CONDITIONS MONDAY NIGHT EXPECTED
TO ALLOW MINS TO FALL INTO THE 40S.

STUBBORN HIGH PRESSURE AND RELENTLESS LOW RH VALUES THROUGH THE
COLUMN WILL REMAIN IN PLACE FOR THE ENTIRE EXTENDED PERIOD. FLOW
WILL CONTINUE TO BE WEAK UNDER AN OMEGA BLOCKING HIGH. TEMPERATURES
WILL TREND SLIGHTLY ABOVE NORMAL WITH NO THREAT OF PRECIPITATION.

MARINE...

WARMER AIRMASS AHEAD OF COLD FRONT...COUPLED WITH THE WEAKENING
PRESSURE GRADIENT AS THE FRONT APPROACHES IS TRANSLATING
TO WIND SPEEDS BELOW 25 KNOTS...AND WILL DROP THE SMALL CRAFT
ADVISORIES. HOWEVER...SHOWERS AND THUNDERSTORMS WILL LIKELY
DEVELOP...AND THUNDERSTORMS WILL BE STRONG TO POSSIBLY SEVERE INTO
TONIGHT. A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO
ADDITIONAL SHOWERS TOMORROW AND POSSIBLE THUNDERSTORMS. BRISK
NORTHERLY WINDS OF 20 TO 25 KNOTS WILL FOLLOW THIS FRONT...ALLOWING
LARGE WAVE TO BUILD OVER SOUTHERN LAKE HURON SUNDAY NIGHT INTO
MONDAY...WITH SMALL CRAFT ADVISORIES LIKELY NEED DURING THAT TIME
FRAME. HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS
DURING THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...ISSUED 1251 PM EDT SAT SEP 20 2014

//DISCUSSION...

FORCING ALONG LEAD OUTFLOW BOUNDARY/WEAK MCV CENTER SHOULD BRING SCT
CONVECTION TO LOWER MICHIGAN BY 17Z-19Z...WELL AHEAD OF THE SYNOPTIC
TROUGH AXIS WEST OVER WISCONSIN. THIS ACTIVITY WILL ORGANIZE TO SOME
DEGREE AS IT MOVES INTO TERMINALS...BUT GIVEN THE EARLIER ARRIVAL OF
ACTIVITY...INSTABILITY WILL REMAIN LIMITED AS SURFACE DEW POINTS
STRUGGLE TOWARDS 60F IN ADVANCE OF THIS INITIAL ACTIVITY.

AFTER THIS PUSH OF SHRAS/EMBEDDED THUNDER...HIGHER THETA-E AIR WILL
CONTINUE TO FUNNEL INTO AREA IN ADVANCE OF MAIN TROUGH...LEADING TO
A CONTINUATION OF RATHER DISORGANIZED CONVECTION INTO THE EVENING
GENERALLY SOUTH OF M 59. RENEWED ACTIVITY CAN THEN BE EXPECTED BY
LATE TONIGHT/SUNDAY MORNING AS MAIN UPPER SHORTWAVE DIGS INTO THE
AREA...DURING WHICH TIME CIGS WILL CONSISTENTLY DROP TO MVFR OR
PERHAPS IFR AT TIMES.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW BEYOND 22Z
THIS AFTERNOON.

* LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET AFTER 22Z...WITH
PROGRESSIVELY HIGHER CONFIDENCE FROM TONIGHT INTO SUNDAY MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

UPDATE.......SC
AVIATION.....DG
SHORT TERM...DG
LONG TERM....SF/MM
MARINE.......SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 210113
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
913 PM EDT SAT SEP 20 2014

.UPDATE...

STRONG MID LEVEL SUBSIDENCE NOW OVERSPREADING SE MI IN THE WAKE OF
THE EARLIER CONVECTIVE ACTIVITY WILL SUPPRESS ADDITIONAL SHRA/TSTM
DEVELOPMENT FOR THE REST OF THE EVENING AND FIRST HALF OF THE
OVERNIGHT. THERE HAS BEEN CONVECTIVE DEVELOPMENT ALONG A COLD
FRONT OVER NORTHERN LOWER MI. THIS FRONT WILL PUSH ACROSS THE
SAGINAW VALLEY AND THUMB REGION LATE TONIGHT INTO EARLY SUN
MORNING. THE 00Z GRB SOUNDING SHOWED FAIRLY STEEP MID LEVEL LAPSE
RATES...SUPPORTING GOOD ELEVATED INSTABILITY. THE SECONDARY MID
LEVEL WAVE NOW TRAVERSING MN THIS EVENING WILL PROVIDE ANOTHER
ROUND OF LARGE SCALE ASCENT LATE TONIGHT INTO SUN MORNING. COOLING
ALOFT ASSOCIATED WITH THIS WAVE WILL IN TURN STEEPEN THE MID LEVEL
LAPSE RATES OVER SE MI. THUS ADDITIONAL CONVECTION IS POSSIBLE
LATE ACROSS THE NORTH HALF OF THE FORECAST AREA WITH THE APPROACH
OF THE FRONT. THE CHANCES FOR SHRA/TSTM WILL THEN INCREASE FURTHOR
SOUTH SUNDAY MORNING INTO AFTERNOON AS THE FRONT PUSHES THROUGH
AND THE UPPER WAVE PASSES OVERHEAD. AN UPDATED FORECAST PACKAGE
REFLECTING THIS WILL BE FORTHCOMING.

&&

.PREV DISCUSSION...ISSUED 314 PM EDT SAT SEP 20 2014

SHORT TERM...THIS AFTERNOON AND TONIGHT

SEVERAL OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION WELL TO THE
WEST ARE TRACKING ACROSS LOWER MICHIGAN. HOWEVER...18Z DTX SOUNDING
SHOWS A RATHER ROBUST CAP IN THE 875-850MB AREA...WHICH WILL LIKELY
TAKE QUITE SOME TIME TO TOTALLY ERODE. MODELS...INCLUDING PRIMARY
AND PARALLEL HRRR RUNS TODAY...SUGGEST CONVECTION WILL EVENTUALLY
FILL IN ALONG BOTH OUTFLOW BOUNDARY SINKING SOUTH/SOUTHEAST THROUGH
THE CWA AND ALSO ALONG VORTICITY SPOKE FURTHER WEST ASSOCIATED WITH
LEFTOVER WEAK MCV. GIVEN CAPPING...AND THE LACK OF SIGNIFICANT
INSTABILITY...EXPECT THIS ACTIVITY TO REMAIN RATHER DISORGANIZED AND
SUB-SEVERE FOR THE MOST PART.

WILL STILL WATCH FOR THE POTENTIAL OF A FEW SEVERE STORMS AS WIND
FIELDS ARE DECENT...INCREASING FROM 25-30 KNOTS H85-H7 TO 50 KNOTS
AT H5. WITH ADDITIONAL HEATING...TEMPERATURES AROUND 80F DETROIT
SOUTH...OVER THE SOUTHERN CWA AND A LACK OF NOTABLE DEEP LOW LEVEL
MOISTURE...INVERTED-V SOUNDINGS MAY ASSIST IN GUST POTENTIAL GIVEN
THE ABOVE ATMOSPHERIC WIND SPEEDS.

THIS INITIAL PUSH OF FORCING...AND WHATEVER CONVECTION COMES OF
IT...WILL SHIFT EAST/SOUTHEAST OF THE AREA LATE THIS AFTERNOON/EARLY
THIS EVENING. HOWEVER...HIGHER THETA-E AIR WILL CONTINUE TO SHIFT
OVER THE CWA...PARTICULARLY M 59 SOUTH...WITHIN SOUTHWEST FLOW IN
ADVANCE OF MAIN SHORTWAVE TROUGH AXIS. SO...ADDITIONAL SCATTERED
SHOWERS/EMBEDDED STORMS WILL BUILD THROUGH AREA INTO THIS EVENING.
ONCE THIS ACTIVITY EBBS LATE THIS EVENING...EXPECT RENEWED SHOWER
AND STORM DEVELOPMENT LATE TONIGHT AS MAIN UPPER LEVEL SHORTWAVE
DIGS FROM THE UPPER MISSISSIPPI VALLEY INTO THE CENTRAL GREAT LAKES.

WITH MILD...SOUTHWEST FLOW PERSISTING THROUGH THE NIGHT...MINIMUM
TEMPERATURES WILL BE RATHER MILD...HOLDING IN THE 60S IN MOST
LOCATIONS...ESPECIALLY AS FURTHER CLOUDS/PRECIPITATION PROVIDE
ADDITIONAL INSOLATION AND MINIMIZE RADIATIONAL COOLING FURTHER.

LONG TERM...

LATEST WATER VAPOR IMAGERY SHOWS A STRONG BUT PROGRESSIVE UPPER
LEVEL SYSTEM/CIRCULATION OVER SOUTHERN MANITOBA...WITH A STRONGER
EMBEDDED UPPER WAVE AT THE BASE OF THE TROUGH OVER NORTH DAKOTA. IT
IS THIS UPPER WAVE/COLD POOL (-18 TO -19 C) WHICH WILL ARRIVE OVER
SOUTHERN LOWER MICHIGAN SUNDAY MORNING. WITH SOME LEFTOVER LOW LEVEL
MOISTURE AND MORE THAN ADEQUATE MID LEVEL LAPSE RATE (6.5+ C/KM FROM
700-500 MB)...ADDITIONAL SHOWERS AND EMBEDDED THUNDERSTORMS APPEAR
LIKELY DURING SUNDAY. A SECONDARY UPPER WAVE/COLD POOL WILL FOLLOW
ON THE BACKSIDE THROUGH THE WESTERN GREAT LAKES AND INTO THE OHIO
VALLEY. DEEP NORTHERLY FLOW IN THIS SYSTEMS WAKE OVER THE CENTRAL
GREAT LAKES WILL ALLOW FOR SOLID COLD ADVECTION TO TAKE PLACE...AS
850 MB TEMPS LOWER INTO THE LOW SINGLE NUMBERS...WITH SLIGHTLY
NEGATIVE VALUES OVER LAKE HURON...PER 12Z EURO/NAM. AS SUCH...FULLY
ONBOARD WITH THE 12Z NAM 925 MB RH/LOW CLOUDS AS NORTHERLY FLOW
COMES OFF THE RELATIVELY WARM WATERS OF LAKE HURON SUNDAY NIGHT.
HAVE SUBSEQUENTLY RAMPED UP THE CLOUDS MONDAY MORNING...WHICH WILL
LIKELY TAKE MUCH OF THE DAY TO MIX OUT/ERODE...HOLDING MAXES CLOSE
TO 60 DEGREES. FAVORABLE RADIATING CONDITIONS MONDAY NIGHT EXPECTED
TO ALLOW MINS TO FALL INTO THE 40S.

STUBBORN HIGH PRESSURE AND RELENTLESS LOW RH VALUES THROUGH THE
COLUMN WILL REMAIN IN PLACE FOR THE ENTIRE EXTENDED PERIOD. FLOW
WILL CONTINUE TO BE WEAK UNDER AN OMEGA BLOCKING HIGH. TEMPERATURES
WILL TREND SLIGHTLY ABOVE NORMAL WITH NO THREAT OF PRECIPITATION.

MARINE...

WARMER AIRMASS AHEAD OF COLD FRONT...COUPLED WITH THE WEAKENING
PRESSURE GRADIENT AS THE FRONT APPROACHES IS TRANSLATING
TO WIND SPEEDS BELOW 25 KNOTS...AND WILL DROP THE SMALL CRAFT
ADVISORIES. HOWEVER...SHOWERS AND THUNDERSTORMS WILL LIKELY
DEVELOP...AND THUNDERSTORMS WILL BE STRONG TO POSSIBLY SEVERE INTO
TONIGHT. A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO
ADDITIONAL SHOWERS TOMORROW AND POSSIBLE THUNDERSTORMS. BRISK
NORTHERLY WINDS OF 20 TO 25 KNOTS WILL FOLLOW THIS FRONT...ALLOWING
LARGE WAVE TO BUILD OVER SOUTHERN LAKE HURON SUNDAY NIGHT INTO
MONDAY...WITH SMALL CRAFT ADVISORIES LIKELY NEED DURING THAT TIME
FRAME. HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS
DURING THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...ISSUED 1251 PM EDT SAT SEP 20 2014

//DISCUSSION...

FORCING ALONG LEAD OUTFLOW BOUNDARY/WEAK MCV CENTER SHOULD BRING SCT
CONVECTION TO LOWER MICHIGAN BY 17Z-19Z...WELL AHEAD OF THE SYNOPTIC
TROUGH AXIS WEST OVER WISCONSIN. THIS ACTIVITY WILL ORGANIZE TO SOME
DEGREE AS IT MOVES INTO TERMINALS...BUT GIVEN THE EARLIER ARRIVAL OF
ACTIVITY...INSTABILITY WILL REMAIN LIMITED AS SURFACE DEW POINTS
STRUGGLE TOWARDS 60F IN ADVANCE OF THIS INITIAL ACTIVITY.

AFTER THIS PUSH OF SHRAS/EMBEDDED THUNDER...HIGHER THETA-E AIR WILL
CONTINUE TO FUNNEL INTO AREA IN ADVANCE OF MAIN TROUGH...LEADING TO
A CONTINUATION OF RATHER DISORGANIZED CONVECTION INTO THE EVENING
GENERALLY SOUTH OF M 59. RENEWED ACTIVITY CAN THEN BE EXPECTED BY
LATE TONIGHT/SUNDAY MORNING AS MAIN UPPER SHORTWAVE DIGS INTO THE
AREA...DURING WHICH TIME CIGS WILL CONSISTENTLY DROP TO MVFR OR
PERHAPS IFR AT TIMES.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW BEYOND 22Z
THIS AFTERNOON.

* LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET AFTER 22Z...WITH
PROGRESSIVELY HIGHER CONFIDENCE FROM TONIGHT INTO SUNDAY MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

UPDATE.......SC
AVIATION.....DG
SHORT TERM...DG
LONG TERM....SF/MM
MARINE.......SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).









000
FXUS63 KDTX 201914
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
314 PM EDT SAT SEP 20 2014

.SHORT TERM...THIS AFTERNOON AND TONIGHT

SEVERAL OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION WELL TO THE
WEST ARE TRACKING ACROSS LOWER MICHIGAN. HOWEVER...18Z DTX SOUNDING
SHOWS A RATHER ROBUST CAP IN THE 875-850MB AREA...WHICH WILL LIKELY
TAKE QUITE SOME TIME TO TOTALLY ERODE. MODELS...INCLUDING PRIMARY
AND PARALLEL HRRR RUNS TODAY...SUGGEST CONVECTION WILL EVENTUALLY
FILL IN ALONG BOTH OUTFLOW BOUNDARY SINKING SOUTH/SOUTHEAST THROUGH
THE CWA AND ALSO ALONG VORTICITY SPOKE FURTHER WEST ASSOCIATED WITH
LEFTOVER WEAK MCV. GIVEN CAPPING...AND THE LACK OF SIGNIFICANT
INSTABILITY...EXPECT THIS ACTIVITY TO REMAIN RATHER DISORGANIZED AND
SUB-SEVERE FOR THE MOST PART.

WILL STILL WATCH FOR THE POTENTIAL OF A FEW SEVERE STORMS AS WIND
FIELDS ARE DECENT...INCREASING FROM 25-30 KNOTS H85-H7 TO 50 KNOTS
AT H5. WITH ADDITIONAL HEATING...TEMPERATURES AROUND 80F DETROIT
SOUTH...OVER THE SOUTHERN CWA AND A LACK OF NOTABLE DEEP LOW LEVEL
MOISTURE...INVERTED-V SOUNDINGS MAY ASSIST IN GUST POTENTIAL GIVEN
THE ABOVE ATMOSPHERIC WIND SPEEDS.

THIS INITIAL PUSH OF FORCING...AND WHATEVER CONVECTION COMES OF
IT...WILL SHIFT EAST/SOUTHEAST OF THE AREA LATE THIS AFTERNOON/EARLY
THIS EVENING. HOWEVER...HIGHER THETA-E AIR WILL CONTINUE TO SHIFT
OVER THE CWA...PARTICULARLY M 59 SOUTH...WITHIN SOUTHWEST FLOW IN
ADVANCE OF MAIN SHORTWAVE TROUGH AXIS. SO...ADDITIONAL SCATTERED
SHOWERS/EMBEDDED STORMS WILL BUILD THROUGH AREA INTO THIS EVENING.
ONCE THIS ACTIVITY EBBS LATE THIS EVENING...EXPECT RENEWED SHOWER
AND STORM DEVELOPMENT LATE TONIGHT AS MAIN UPPER LEVEL SHORTWAVE
DIGS FROM THE UPPER MISSISSIPPI VALLEY INTO THE CENTRAL GREAT LAKES.

WITH MILD...SOUTHWEST FLOW PERSISTING THROUGH THE NIGHT...MINIMUM
TEMPERATURES WILL BE RATHER MILD...HOLDING IN THE 60S IN MOST
LOCATIONS...ESPECIALLY AS FURTHER CLOUDS/PRECIPITATION PROVIDE
ADDITIONAL INSOLATION AND MINIMIZE RADIATIONAL COOLING FURTHER.

&&

.LONG TERM...

LATEST WATER VAPOR IMAGERY SHOWS A STRONG BUT PROGRESSIVE UPPER
LEVEL SYSTEM/CIRCULATION OVER SOUTHERN MANITOBA...WITH A STRONGER
EMBEDDED UPPER WAVE AT THE BASE OF THE TROUGH OVER NORTH DAKOTA. IT
IS THIS UPPER WAVE/COLD POOL (-18 TO -19 C) WHICH WILL ARRIVE OVER
SOUTHERN LOWER MICHIGAN SUNDAY MORNING. WITH SOME LEFTOVER LOW LEVEL
MOISTURE AND MORE THAN ADEQUATE MID LEVEL LAPSE RATE (6.5+ C/KM FROM
700-500 MB)...ADDITIONAL SHOWERS AND EMBEDDED THUNDERSTORMS APPEAR
LIKELY DURING SUNDAY. A SECONDARY UPPER WAVE/COLD POOL WILL FOLLOW
ON THE BACKSIDE THROUGH THE WESTERN GREAT LAKES AND INTO THE OHIO
VALLEY. DEEP NORTHERLY FLOW IN THIS SYSTEMS WAKE OVER THE CENTRAL
GREAT LAKES WILL ALLOW FOR SOLID COLD ADVECTION TO TAKE PLACE...AS
850 MB TEMPS LOWER INTO THE LOW SINGLE NUMBERS...WITH SLIGHTLY
NEGATIVE VALUES OVER LAKE HURON...PER 12Z EURO/NAM. AS SUCH...FULLY
ONBOARD WITH THE 12Z NAM 925 MB RH/LOW CLOUDS AS NORTHERLY FLOW
COMES OFF THE RELATIVELY WARM WATERS OF LAKE HURON SUNDAY NIGHT.
HAVE SUBSEQUENTLY RAMPED UP THE CLOUDS MONDAY MORNING...WHICH WILL
LIKELY TAKE MUCH OF THE DAY TO MIX OUT/ERODE...HOLDING MAXES CLOSE
TO 60 DEGREES. FAVORABLE RADIATING CONDITIONS MONDAY NIGHT EXPECTED
TO ALLOW MINS TO FALL INTO THE 40S.

STUBBORN HIGH PRESSURE AND RELENTLESS LOW RH VALUES THROUGH THE
COLUMN WILL REMAIN IN PLACE FOR THE ENTIRE EXTENDED PERIOD. FLOW
WILL CONTINUE TO BE WEAK UNDER AN OMEGA BLOCKING HIGH. TEMPERATURES
WILL TREND SLIGHTLY ABOVE NORMAL WITH NO THREAT OF PRECIPITATION.

&&

.MARINE...

WARMER AIRMASS AHEAD OF COLD FRONT...COUPLED WITH THE WEAKENING
PRESSURE GRADIENT AS THE FRONT APPROACHES IS TRANSLATING
TO WIND SPEEDS BELOW 25 KNOTS...AND WILL DROP THE SMALL CRAFT
ADVISORIES. HOWEVER...SHOWERS AND THUNDERSTORMS WILL LIKELY
DEVELOP...AND THUNDERSTORMS WILL BE STRONG TO POSSIBLY SEVERE INTO
TONIGHT. A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO
ADDITIONAL SHOWERS TOMORROW AND POSSIBLE THUNDERSTORMS. BRISK
NORTHERLY WINDS OF 20 TO 25 KNOTS WILL FOLLOW THIS FRONT...ALLOWING
LARGE WAVE TO BUILD OVER SOUTHERN LAKE HURON SUNDAY NIGHT INTO
MONDAY...WITH SMALL CRAFT ADVISORIES LIKELY NEED DURING THAT TIME
FRAME. HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS
DURING THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...ISSUED 1251 PM EDT SAT SEP 20 2014

//DISCUSSION...

FORCING ALONG LEAD OUTFLOW BOUNDARY/WEAK MCV CENTER SHOULD BRING SCT
CONVECTION TO LOWER MICHIGAN BY 17Z-19Z...WELL AHEAD OF THE SYNOPTIC
TROUGH AXIS WEST OVER WISCONSIN. THIS ACTIVITY WILL ORGANIZE TO SOME
DEGREE AS IT MOVES INTO TERMINALS...BUT GIVEN THE EARLIER ARRIVAL OF
ACTIVITY...INSTABILITY WILL REMAIN LIMITED AS SURFACE DEW POINTS
STRUGGLE TOWARDS 60F IN ADVANCE OF THIS INITIAL ACTIVITY.

AFTER THIS PUSH OF SHRAS/EMBEDDED THUNDER...HIGHER THETA-E AIR WILL
CONTINUE TO FUNNEL INTO AREA IN ADVANCE OF MAIN TROUGH...LEADING TO
A CONTINUATION OF RATHER DISORGANIZED CONVECTION INTO THE EVENING
GENERALLY SOUTH OF M 59. RENEWED ACTIVITY CAN THEN BE EXPECTED BY
LATE TONIGHT/SUNDAY MORNING AS MAIN UPPER SHORTWAVE DIGS INTO THE
AREA...DURING WHICH TIME CIGS WILL CONSISTENTLY DROP TO MVFR OR
PERHAPS IFR AT TIMES.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW BEYOND 22Z
THIS AFTERNOON.

* LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET AFTER 22Z...WITH
PROGRESSIVELY HIGHER CONFIDENCE FROM TONIGHT INTO SUNDAY MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
     PORT AUSTIN TO HARBOR BEACH...UNTIL 8 PM SATURDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...DG
LONG TERM....SF/MM
MARINE.......SF
AVIATION.....DG


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 201914
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
314 PM EDT SAT SEP 20 2014

.SHORT TERM...THIS AFTERNOON AND TONIGHT

SEVERAL OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION WELL TO THE
WEST ARE TRACKING ACROSS LOWER MICHIGAN. HOWEVER...18Z DTX SOUNDING
SHOWS A RATHER ROBUST CAP IN THE 875-850MB AREA...WHICH WILL LIKELY
TAKE QUITE SOME TIME TO TOTALLY ERODE. MODELS...INCLUDING PRIMARY
AND PARALLEL HRRR RUNS TODAY...SUGGEST CONVECTION WILL EVENTUALLY
FILL IN ALONG BOTH OUTFLOW BOUNDARY SINKING SOUTH/SOUTHEAST THROUGH
THE CWA AND ALSO ALONG VORTICITY SPOKE FURTHER WEST ASSOCIATED WITH
LEFTOVER WEAK MCV. GIVEN CAPPING...AND THE LACK OF SIGNIFICANT
INSTABILITY...EXPECT THIS ACTIVITY TO REMAIN RATHER DISORGANIZED AND
SUB-SEVERE FOR THE MOST PART.

WILL STILL WATCH FOR THE POTENTIAL OF A FEW SEVERE STORMS AS WIND
FIELDS ARE DECENT...INCREASING FROM 25-30 KNOTS H85-H7 TO 50 KNOTS
AT H5. WITH ADDITIONAL HEATING...TEMPERATURES AROUND 80F DETROIT
SOUTH...OVER THE SOUTHERN CWA AND A LACK OF NOTABLE DEEP LOW LEVEL
MOISTURE...INVERTED-V SOUNDINGS MAY ASSIST IN GUST POTENTIAL GIVEN
THE ABOVE ATMOSPHERIC WIND SPEEDS.

THIS INITIAL PUSH OF FORCING...AND WHATEVER CONVECTION COMES OF
IT...WILL SHIFT EAST/SOUTHEAST OF THE AREA LATE THIS AFTERNOON/EARLY
THIS EVENING. HOWEVER...HIGHER THETA-E AIR WILL CONTINUE TO SHIFT
OVER THE CWA...PARTICULARLY M 59 SOUTH...WITHIN SOUTHWEST FLOW IN
ADVANCE OF MAIN SHORTWAVE TROUGH AXIS. SO...ADDITIONAL SCATTERED
SHOWERS/EMBEDDED STORMS WILL BUILD THROUGH AREA INTO THIS EVENING.
ONCE THIS ACTIVITY EBBS LATE THIS EVENING...EXPECT RENEWED SHOWER
AND STORM DEVELOPMENT LATE TONIGHT AS MAIN UPPER LEVEL SHORTWAVE
DIGS FROM THE UPPER MISSISSIPPI VALLEY INTO THE CENTRAL GREAT LAKES.

WITH MILD...SOUTHWEST FLOW PERSISTING THROUGH THE NIGHT...MINIMUM
TEMPERATURES WILL BE RATHER MILD...HOLDING IN THE 60S IN MOST
LOCATIONS...ESPECIALLY AS FURTHER CLOUDS/PRECIPITATION PROVIDE
ADDITIONAL INSOLATION AND MINIMIZE RADIATIONAL COOLING FURTHER.

&&

.LONG TERM...

LATEST WATER VAPOR IMAGERY SHOWS A STRONG BUT PROGRESSIVE UPPER
LEVEL SYSTEM/CIRCULATION OVER SOUTHERN MANITOBA...WITH A STRONGER
EMBEDDED UPPER WAVE AT THE BASE OF THE TROUGH OVER NORTH DAKOTA. IT
IS THIS UPPER WAVE/COLD POOL (-18 TO -19 C) WHICH WILL ARRIVE OVER
SOUTHERN LOWER MICHIGAN SUNDAY MORNING. WITH SOME LEFTOVER LOW LEVEL
MOISTURE AND MORE THAN ADEQUATE MID LEVEL LAPSE RATE (6.5+ C/KM FROM
700-500 MB)...ADDITIONAL SHOWERS AND EMBEDDED THUNDERSTORMS APPEAR
LIKELY DURING SUNDAY. A SECONDARY UPPER WAVE/COLD POOL WILL FOLLOW
ON THE BACKSIDE THROUGH THE WESTERN GREAT LAKES AND INTO THE OHIO
VALLEY. DEEP NORTHERLY FLOW IN THIS SYSTEMS WAKE OVER THE CENTRAL
GREAT LAKES WILL ALLOW FOR SOLID COLD ADVECTION TO TAKE PLACE...AS
850 MB TEMPS LOWER INTO THE LOW SINGLE NUMBERS...WITH SLIGHTLY
NEGATIVE VALUES OVER LAKE HURON...PER 12Z EURO/NAM. AS SUCH...FULLY
ONBOARD WITH THE 12Z NAM 925 MB RH/LOW CLOUDS AS NORTHERLY FLOW
COMES OFF THE RELATIVELY WARM WATERS OF LAKE HURON SUNDAY NIGHT.
HAVE SUBSEQUENTLY RAMPED UP THE CLOUDS MONDAY MORNING...WHICH WILL
LIKELY TAKE MUCH OF THE DAY TO MIX OUT/ERODE...HOLDING MAXES CLOSE
TO 60 DEGREES. FAVORABLE RADIATING CONDITIONS MONDAY NIGHT EXPECTED
TO ALLOW MINS TO FALL INTO THE 40S.

STUBBORN HIGH PRESSURE AND RELENTLESS LOW RH VALUES THROUGH THE
COLUMN WILL REMAIN IN PLACE FOR THE ENTIRE EXTENDED PERIOD. FLOW
WILL CONTINUE TO BE WEAK UNDER AN OMEGA BLOCKING HIGH. TEMPERATURES
WILL TREND SLIGHTLY ABOVE NORMAL WITH NO THREAT OF PRECIPITATION.

&&

.MARINE...

WARMER AIRMASS AHEAD OF COLD FRONT...COUPLED WITH THE WEAKENING
PRESSURE GRADIENT AS THE FRONT APPROACHES IS TRANSLATING
TO WIND SPEEDS BELOW 25 KNOTS...AND WILL DROP THE SMALL CRAFT
ADVISORIES. HOWEVER...SHOWERS AND THUNDERSTORMS WILL LIKELY
DEVELOP...AND THUNDERSTORMS WILL BE STRONG TO POSSIBLY SEVERE INTO
TONIGHT. A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO
ADDITIONAL SHOWERS TOMORROW AND POSSIBLE THUNDERSTORMS. BRISK
NORTHERLY WINDS OF 20 TO 25 KNOTS WILL FOLLOW THIS FRONT...ALLOWING
LARGE WAVE TO BUILD OVER SOUTHERN LAKE HURON SUNDAY NIGHT INTO
MONDAY...WITH SMALL CRAFT ADVISORIES LIKELY NEED DURING THAT TIME
FRAME. HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS
DURING THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...ISSUED 1251 PM EDT SAT SEP 20 2014

//DISCUSSION...

FORCING ALONG LEAD OUTFLOW BOUNDARY/WEAK MCV CENTER SHOULD BRING SCT
CONVECTION TO LOWER MICHIGAN BY 17Z-19Z...WELL AHEAD OF THE SYNOPTIC
TROUGH AXIS WEST OVER WISCONSIN. THIS ACTIVITY WILL ORGANIZE TO SOME
DEGREE AS IT MOVES INTO TERMINALS...BUT GIVEN THE EARLIER ARRIVAL OF
ACTIVITY...INSTABILITY WILL REMAIN LIMITED AS SURFACE DEW POINTS
STRUGGLE TOWARDS 60F IN ADVANCE OF THIS INITIAL ACTIVITY.

AFTER THIS PUSH OF SHRAS/EMBEDDED THUNDER...HIGHER THETA-E AIR WILL
CONTINUE TO FUNNEL INTO AREA IN ADVANCE OF MAIN TROUGH...LEADING TO
A CONTINUATION OF RATHER DISORGANIZED CONVECTION INTO THE EVENING
GENERALLY SOUTH OF M 59. RENEWED ACTIVITY CAN THEN BE EXPECTED BY
LATE TONIGHT/SUNDAY MORNING AS MAIN UPPER SHORTWAVE DIGS INTO THE
AREA...DURING WHICH TIME CIGS WILL CONSISTENTLY DROP TO MVFR OR
PERHAPS IFR AT TIMES.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW BEYOND 22Z
THIS AFTERNOON.

* LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET AFTER 22Z...WITH
PROGRESSIVELY HIGHER CONFIDENCE FROM TONIGHT INTO SUNDAY MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
     PORT AUSTIN TO HARBOR BEACH...UNTIL 8 PM SATURDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...DG
LONG TERM....SF/MM
MARINE.......SF
AVIATION.....DG


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 201651
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1251 PM EDT SAT SEP 20 2014


.AVIATION...

//DISCUSSION...

FORCING ALONG LEAD OUTFLOW BOUNDARY/WEAK MCV CENTER SHOULD BRING SCT
CONVECTION TO LOWER MICHIGAN BY 17Z-19Z...WELL AHEAD OF THE SYNOPTIC
TROUGH AXIS WEST OVER WISCONSIN. THIS ACTIVITY WILL ORGANIZE TO SOME
DEGREE AS IT MOVES INTO TERMINALS...BUT GIVEN THE EARLIER ARRIVAL OF
ACTIVITY...INSTABILITY WILL REMAIN LIMITED AS SURFACE DEW POINTS
STRUGGLE TOWARDS 60F IN ADVANCE OF THIS INITIAL ACTIVITY.

AFTER THIS PUSH OF SHRAS/EMBEDDED THUNDER...HIGHER THETA-E AIR WILL
CONTINUE TO FUNNEL INTO AREA IN ADVANCE OF MAIN TROUGH...LEADING TO
A CONTINUATION OF RATHER DISORGANIZED CONVECTION INTO THE EVENING
GENERALLY SOUTH OF M 59. RENEWED ACTIVITY CAN THEN BE EXPECTED BY
LATE TONIGHT/SUNDAY MORNING AS MAIN UPPER SHORTWAVE DIGS INTO THE
AREA...DURING WHICH TIME CIGS WILL CONSISTENTLY DROP TO MVFR OR
PERHAPS IFR AT TIMES.


//DTW THRESHOLD THREATS...

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW BEYOND 22Z
THIS AFTERNOON.

* LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET AFTER 22Z...WITH
PROGRESSIVELY HIGHER CONFIDENCE FROM TONIGHT INTO SUNDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 405 AM EDT SAT SEP 20 2014

SHORT TERM...TODAY AND TONIGHT

TODAY. CONVECTION IS ONGOING WITHIN THE UPSTREAM THETA-E AXIS THAT
HAS BEEN DRAWN INTO THE UPPER MS VALLEY AHEAD OF THE BROAD CORRIDOR
OF HEIGHT FALLS SPREADING INTO THE NORTHERN U.S. CONVECTIVE DEBRIS
OVER IA/WI/IL WILL SPREAD EAST NORTHEAST DURING THE MORNING,
ENGULFING MOST OR ALL OF THE FORECAST AREA BY EARLY AFTN. SUBSEQUENT
LIMITED INSOLATION WILL RESULT IN SUSPECT PROSPECTS FOR INSTABILITY
TODAY AS THE THETA-E AXIS FOLDS EAST AND INTO THE AREA. 00Z NAM/RAP
DO STILL SUGGEST A RIBBON OF 1000 J/KG ADVECTING INTO NORTHWEST HALF
OF THE CWA DURING THE AFTERNOON, A REASONABLE PROSPECT GIVEN THE
HEALTHY SOUTHWEST GRADIENT FLOW. IN ADDITION, THE 00Z SUITE HAVE PICKED
UP ON THE POTENT LOW AMPLITUDE SHORTWAVE SEEN DIVING SOUTHEAST OUT OF
MONTANA AT 06Z THIS MORNING. THIS WAVE WAS EITHER UNDERSIMULATED OR
NON-EXISTENT IN THE 12Z GUIDANCE, AND THE MOST RECENT SIMULATIONS
SUGGEST THAT IT WILL BE SUFFICIENTLY STRONG TO INITIATE CONVECTION
ACROSS WESTERN LOWER MI THIS AFTERNOON. 0-6KM SHEAR ON THE ORDER OF
35 KTS FUELED BY A MODERATE SWLY LOW-LEVEL JET WILL BE SUFFICIENT
FOR ORGANIZATION OF THE STRONGEST UPDRAFTS. BUT GENERALLY SPEAKING,
MARGINAL INSTABILITY/LOW CAPE DENSITY WILL BE RESTRICTIVE OF SEVERE
CONVECTION. EXPECT NOTHING MORE THAN A MARGINAL SEVERE WIND/HAIL
THREAT THIS AFTERNOON, MAINLY FOCUSED ACROSS THE NORTHWESTERN HALF
OF THE AREA WHERE CONVECTIVE POTENTIAL WILL MOST FAVORABLY COINCIDE
WITH PEAK HEATING. AFOREMENTIONED SWLY GRADIENT AND WELL-MIXED
BOUNDARY LAYER TO AROUND 875MB WILL RESULT WARM/GUSTY DAY WITH HIGHS
OF 75 TO 80 AND WIND GUSTS TO 25 MPH.

TONIGHT. CYCLONIC SHEAR MAX ALONG THE COLD SIDE OF THE 120KT DIVING
OUT OF CANADA THIS MORNING WILL UNDERGO CONSIDERABLE AMPLIFICATION
AS IT APPROACHES THE GREAT LAKES TONIGHT. SOUTHWESTERLY ADVECTION OF
WARMER LOW-LEVEL AIR AND RAPIDLY COOLING HEIGHTS ALOFT WILL MAINTAIN
1000 TO 2000 J/KG OF CAPE FOR THE BALANCE OF THE NIGHT. AT THE SAME
TIME, THE RAPIDLY TIGHTENING MASS GRADIENT WILL ALLOW A 70 KNOT H5
JET TO IMPINGE ON THE FORECAST AREA RESULTING IN A 0-6KM BULK SHEAR
SOLIDLY IN 60-70 KNOT RANGE BY AROUND 09Z. MEANWHILE, THE LOW-LEVEL
WIND RESPONSE WILL FACILITATE A SECOND THETA-E SURGE INTO THE AREA
POST-06Z WITHIN A BAND OF INCREASING 300-310K SYSTEM RELATIVE
ISENTROPIC ASCENT. IN THE PRESENCE OF INCREASING LARGE SCALE ASCENT,
THIS WILL BE SUPPORTIVE OF ADDITIONAL CONVECTIVE DEVELOPMENT OVER
THE AREA LATE TONIGHT. GIVEN THE PARAMETERS, THE POTENTIAL FOR
MESOCYCLONE DEVELOPMENT AND A SUBSEQUENT SEVERE RISK IS READILY
EVIDENT. HOWEVER, MODELED SOUNDINGS ONCE AGAIN SUGGEST A RATHER LOW
CAPE DENSITY WHICH, GIVEN THE MAGNITUDE OF MID-LEVEL WINDS, MAY
SIMPLY RESULT IN DECAPITATION OF UPDRAFTS AT 15KFT OR SO. THE NATURE
OF TONIGHT`S INSTABILITY PROFILE WILL BE A KEY HERE, BUT ATTM IT
APPEARS LESS IMPRESSIVE IN REALITY THAN IT DOES IN PARAMETER SPACE.
NONETHELESS, OBVIOUSLY CAN`T COMPLETELY RULE OUT SEVERE RISK IN THIS
TYPE OF ENVIRONMENT. THE BEST CHANCE FOR SEVERE WIND/HAIL THREAT
WILL MOST LIKELY LIE ALONG THE EHI MAX WHICH IS CURRENTLY PROGGED TO
ALIGN ALONG/NORTH OF M59, BUT ALL AREAS WILL CARRY AT LEAST A LOW
SLIGHT RISK THROUGH 12Z.

LONG TERM...

THE NEXT SHORT WAVE WILL BE CLOSE ON THE HEELS OF TODAY`S SYSTEM AND
ARRIVE IN TIME TO BRING UNSETTLED WEATHER IN SE MICHIGAN FOR MUCH OF
SUNDAY. THE SYSTEM IS INDICATED IN MORNING SATELLITE IMAGERY MOVING
THROUGH CENTRAL CANADA AND DISPLAYS BOTH ENERGETIC CIRCULATION AND
TEXTURE/CONVECTION IN SUPPORT OF DEPICTIONS IN THE NEW MODEL CYCLE.
UPPER AIR OBSERVATIONS AND MODEL ANALYSIS FIELDS INDICATE
CONSIDERABLY COLDER AIR ALOFT WITH THIS SYSTEM...PUSHING -20C AT 500
MB...THAT WILL BE CARRIED OVER LOWER MICHIGAN DURING DAYTIME
HEATING. IN ADDITION...THE WAVE ITSELF WILL FEED OFF CONTINUED LONG
WAVE AMPLIFICATION AND 100 KT UPPER JET AXIS FOR STRENGTHENING
DYNAMIC SUPPORT OF LARGE SCALE LIFT. IT`S NO SURPRISE THAT MODEL
SOUNDINGS CARRY AN UNSTABLE PROFILE THROUGH THE NIGHT AND SUNDAY
MORNING AS 0-6KM BULK SHEAR RISES TO 50 KNOTS. AN IMPORTANT
DIFFERENCE AMONG THE INDIVIDUAL SOLUTIONS IS IN THE HANDLING OF
BOUNDARY LAYER MOISTURE AND THE RESULTING CAPE PROFILE AS THE COLD
CORE ALOFT MOVES OVERHEAD. THE NAM IS ALONE IN MAINTAINING SURFACE
DEWPOINT IN THE UPPER 60S WITH LITTLE OR NO DRY AIR ADVECTION BEHIND
THE PREFRONTAL TROUGH DRIVING TODAY`S ACTIVITY. THE RESULT IS
SURFACE BASED CAPE NEAR 1500 J/KG BY 15Z ON EARLY DAY MAX TEMPS IN
THE UPPER 60S TO LOWER 70S WHILE THE GFS, ECMWF, AND MOST OF THE
LATEST SREF MEMBERS DROP CAPE BELOW 1000 J/KG WITH SURFACE DEWPOINT
IN THE UPPER 50S TO PERHAPS LOWER 60S OVER THE FAR SOUTHEAST.
HOWEVER...THERE IS SOME MERIT TO THE NAM SOLUTION AS SURFACE
PRESSURE FALLS OVER THE UPPER MIDWEST ELONGATE THE PRIMARY SURFACE
TROUGH ENOUGH TO ALTER THE DOWNSTREAM WIND PATTERN AND POSSIBLY
STALL THE EXIT OF THE LOW LEVEL THETA-E RIDGE AND/OR SIPHON SOME
EXTRA MOISTURE WESTWARD. AT THIS POINT...IT SEEMS PRUDENT TO MAKE
THE SYSTEM PROVE IT WON`T OVERACHIEVE. THEREFORE...LIKELY POPS FOR
SHOWERS WITH A CHANCE OF THUNDERSTORMS WILL BE MAINTAINED IN THE
FORECAST. CONVECTIVE ORGANIZATION WILL STRONGLY DEPEND ON THE
EVENTUAL AMOUNT OF INSTABILITY AVAILABLE TO GO ALONG WITH THE STRONG
WIND FIELD. STORMS HAVE THE POTENTIAL FOR STRONG WIND GUSTS AND
SMALL HAIL GIVEN THE COLD CORE ALOFT AND LOW FREEZING LEVEL.

THE SUNDAY SYSTEM WILL EXIT THE GREAT LAKES QUICKLY BY EVENING AND
OPEN THE DOOR FOR COOLER AIR TO SPREAD OVER THE REGION THROUGH
SUNDAY NIGHT. STRONG LOW LEVEL COLD ADVECTION SHOWN IN ALL MODEL
SOLUTIONS WILL CARRY 850 MB TEMPS DOWN INTO THE SINGLE DIGITS BY
MONDAY MORNING ON ROBUST NORTHERLY FLOW. THIS WILL CONFINE MAX TEMPS
TO THE LOWER HALF OF THE 60S...AND LIKELY LIMIT TO UPPER 50S NEAR
THE LAKE HURON SHORELINE.

GLOBAL MODEL SOLUTIONS ARE STABLE ON THE LONG WAVE UPPER LEVEL
PATTERN DURING MID WEEK. A FULL LATITUDE TROUGH OFF THE PACIFIC
COAST WILL ANCHOR A BROAD/DEAMPLIFIED RIDGE OVER MUCH OF NORTH
AMERICA AS THE EASTERN CANADIAN UPPER TROUGH MOVES TOWARD THE NORTH
ATLANTIC. THE BROAD NATURE OF THE RIDGE WILL ALLOW A SLOW ABSORPTION
OF THE CALIFORNIA CLOSED LOW BACK INTO THE WESTERLIES AND AN EQUALLY
SLOW MIGRATION INTO THE PLAINS. THE PRIMARY IMPACT THIS HAS ON THE
FORECAST FOR SE MICHIGAN IS RELATED TO AN EASTWARD DISPLACEMENT OF
NORTHWEST FLOW ALOFT AND A LESS AGGRESSIVE BACKDOOR SURFACE FRONT
INTO THE GREAT LAKES TUESDAY. THIS WAS A BENIGN FEATURE IN PREVIOUS
MODEL RUNS AND IS RENDERED EVEN MORE SO ON THE BACKGROUND OF THE
LATEST DEPICTIONS OF LARGE SCALE PATTERN EVOLUTION. THE END RESULT
WILL BE A RESURGENCE OF SURFACE HIGH PRESSURE THROUGH THE MID WEEK
PERIOD THAT WILL SUPPORT DRY WEATHER WITH NEAR NORMAL TEMPERATURES
UNTIL POSSIBLY FRIDAY WHEN REMNANTS OF THE PLAINS SHORT WAVE COULD
BRING A LOW CHANCE OF RAIN.

MARINE...

SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH TODAY FOR SAGINAW
BAY AROUND THE TIP OF THE THUMB. THIS IS WHERE SOUTHWEST FLOW WILL
BE STRONGEST AS IT CHANNELS DOWN THE BAY AND ALONG THE THUMB
SHORELINE. CONDITIONS WILL BECOME INCREASINGLY UNSETTLED ACROSS ALL
MARINE AREAS AS A PATTERN OF SHOWERS AND THUNDERSTORMS DEVELOPS AND
MOVES ACROSS THE REGION DURING THE AFTERNOON AND TONIGHT. ADDITIONAL
SHOWERS AND STORMS ARE THEN POSSIBLE WITH THE PRIMARY COLD FRONT
THAT WILL SHIFT THE WIND TOWARD THE NORTH SUNDAY AND SUNDAY NIGHT
THROUGH MONDAY. SMALL CRAFT ADVISORIES MAY BE NEEDED AGAIN FOR THE
LARGE WAVE RESPONSE ON THE SOUTH HALF OF LAKE HURON. HIGH PRESSURE
WILL EXERT FAVORABLE INFLUENCE ON THE WATERS DURING THE MIDDLE OF
NEXT WEEK.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
     PORT AUSTIN TO HARBOR BEACH...UNTIL 8 PM SATURDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....DG
SHORT TERM...JVC
LONG TERM....BT
MARINE.......BT


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).








000
FXUS63 KDTX 201651
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1251 PM EDT SAT SEP 20 2014


.AVIATION...

//DISCUSSION...

FORCING ALONG LEAD OUTFLOW BOUNDARY/WEAK MCV CENTER SHOULD BRING SCT
CONVECTION TO LOWER MICHIGAN BY 17Z-19Z...WELL AHEAD OF THE SYNOPTIC
TROUGH AXIS WEST OVER WISCONSIN. THIS ACTIVITY WILL ORGANIZE TO SOME
DEGREE AS IT MOVES INTO TERMINALS...BUT GIVEN THE EARLIER ARRIVAL OF
ACTIVITY...INSTABILITY WILL REMAIN LIMITED AS SURFACE DEW POINTS
STRUGGLE TOWARDS 60F IN ADVANCE OF THIS INITIAL ACTIVITY.

AFTER THIS PUSH OF SHRAS/EMBEDDED THUNDER...HIGHER THETA-E AIR WILL
CONTINUE TO FUNNEL INTO AREA IN ADVANCE OF MAIN TROUGH...LEADING TO
A CONTINUATION OF RATHER DISORGANIZED CONVECTION INTO THE EVENING
GENERALLY SOUTH OF M 59. RENEWED ACTIVITY CAN THEN BE EXPECTED BY
LATE TONIGHT/SUNDAY MORNING AS MAIN UPPER SHORTWAVE DIGS INTO THE
AREA...DURING WHICH TIME CIGS WILL CONSISTENTLY DROP TO MVFR OR
PERHAPS IFR AT TIMES.


//DTW THRESHOLD THREATS...

* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW BEYOND 22Z
THIS AFTERNOON.

* LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET AFTER 22Z...WITH
PROGRESSIVELY HIGHER CONFIDENCE FROM TONIGHT INTO SUNDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 405 AM EDT SAT SEP 20 2014

SHORT TERM...TODAY AND TONIGHT

TODAY. CONVECTION IS ONGOING WITHIN THE UPSTREAM THETA-E AXIS THAT
HAS BEEN DRAWN INTO THE UPPER MS VALLEY AHEAD OF THE BROAD CORRIDOR
OF HEIGHT FALLS SPREADING INTO THE NORTHERN U.S. CONVECTIVE DEBRIS
OVER IA/WI/IL WILL SPREAD EAST NORTHEAST DURING THE MORNING,
ENGULFING MOST OR ALL OF THE FORECAST AREA BY EARLY AFTN. SUBSEQUENT
LIMITED INSOLATION WILL RESULT IN SUSPECT PROSPECTS FOR INSTABILITY
TODAY AS THE THETA-E AXIS FOLDS EAST AND INTO THE AREA. 00Z NAM/RAP
DO STILL SUGGEST A RIBBON OF 1000 J/KG ADVECTING INTO NORTHWEST HALF
OF THE CWA DURING THE AFTERNOON, A REASONABLE PROSPECT GIVEN THE
HEALTHY SOUTHWEST GRADIENT FLOW. IN ADDITION, THE 00Z SUITE HAVE PICKED
UP ON THE POTENT LOW AMPLITUDE SHORTWAVE SEEN DIVING SOUTHEAST OUT OF
MONTANA AT 06Z THIS MORNING. THIS WAVE WAS EITHER UNDERSIMULATED OR
NON-EXISTENT IN THE 12Z GUIDANCE, AND THE MOST RECENT SIMULATIONS
SUGGEST THAT IT WILL BE SUFFICIENTLY STRONG TO INITIATE CONVECTION
ACROSS WESTERN LOWER MI THIS AFTERNOON. 0-6KM SHEAR ON THE ORDER OF
35 KTS FUELED BY A MODERATE SWLY LOW-LEVEL JET WILL BE SUFFICIENT
FOR ORGANIZATION OF THE STRONGEST UPDRAFTS. BUT GENERALLY SPEAKING,
MARGINAL INSTABILITY/LOW CAPE DENSITY WILL BE RESTRICTIVE OF SEVERE
CONVECTION. EXPECT NOTHING MORE THAN A MARGINAL SEVERE WIND/HAIL
THREAT THIS AFTERNOON, MAINLY FOCUSED ACROSS THE NORTHWESTERN HALF
OF THE AREA WHERE CONVECTIVE POTENTIAL WILL MOST FAVORABLY COINCIDE
WITH PEAK HEATING. AFOREMENTIONED SWLY GRADIENT AND WELL-MIXED
BOUNDARY LAYER TO AROUND 875MB WILL RESULT WARM/GUSTY DAY WITH HIGHS
OF 75 TO 80 AND WIND GUSTS TO 25 MPH.

TONIGHT. CYCLONIC SHEAR MAX ALONG THE COLD SIDE OF THE 120KT DIVING
OUT OF CANADA THIS MORNING WILL UNDERGO CONSIDERABLE AMPLIFICATION
AS IT APPROACHES THE GREAT LAKES TONIGHT. SOUTHWESTERLY ADVECTION OF
WARMER LOW-LEVEL AIR AND RAPIDLY COOLING HEIGHTS ALOFT WILL MAINTAIN
1000 TO 2000 J/KG OF CAPE FOR THE BALANCE OF THE NIGHT. AT THE SAME
TIME, THE RAPIDLY TIGHTENING MASS GRADIENT WILL ALLOW A 70 KNOT H5
JET TO IMPINGE ON THE FORECAST AREA RESULTING IN A 0-6KM BULK SHEAR
SOLIDLY IN 60-70 KNOT RANGE BY AROUND 09Z. MEANWHILE, THE LOW-LEVEL
WIND RESPONSE WILL FACILITATE A SECOND THETA-E SURGE INTO THE AREA
POST-06Z WITHIN A BAND OF INCREASING 300-310K SYSTEM RELATIVE
ISENTROPIC ASCENT. IN THE PRESENCE OF INCREASING LARGE SCALE ASCENT,
THIS WILL BE SUPPORTIVE OF ADDITIONAL CONVECTIVE DEVELOPMENT OVER
THE AREA LATE TONIGHT. GIVEN THE PARAMETERS, THE POTENTIAL FOR
MESOCYCLONE DEVELOPMENT AND A SUBSEQUENT SEVERE RISK IS READILY
EVIDENT. HOWEVER, MODELED SOUNDINGS ONCE AGAIN SUGGEST A RATHER LOW
CAPE DENSITY WHICH, GIVEN THE MAGNITUDE OF MID-LEVEL WINDS, MAY
SIMPLY RESULT IN DECAPITATION OF UPDRAFTS AT 15KFT OR SO. THE NATURE
OF TONIGHT`S INSTABILITY PROFILE WILL BE A KEY HERE, BUT ATTM IT
APPEARS LESS IMPRESSIVE IN REALITY THAN IT DOES IN PARAMETER SPACE.
NONETHELESS, OBVIOUSLY CAN`T COMPLETELY RULE OUT SEVERE RISK IN THIS
TYPE OF ENVIRONMENT. THE BEST CHANCE FOR SEVERE WIND/HAIL THREAT
WILL MOST LIKELY LIE ALONG THE EHI MAX WHICH IS CURRENTLY PROGGED TO
ALIGN ALONG/NORTH OF M59, BUT ALL AREAS WILL CARRY AT LEAST A LOW
SLIGHT RISK THROUGH 12Z.

LONG TERM...

THE NEXT SHORT WAVE WILL BE CLOSE ON THE HEELS OF TODAY`S SYSTEM AND
ARRIVE IN TIME TO BRING UNSETTLED WEATHER IN SE MICHIGAN FOR MUCH OF
SUNDAY. THE SYSTEM IS INDICATED IN MORNING SATELLITE IMAGERY MOVING
THROUGH CENTRAL CANADA AND DISPLAYS BOTH ENERGETIC CIRCULATION AND
TEXTURE/CONVECTION IN SUPPORT OF DEPICTIONS IN THE NEW MODEL CYCLE.
UPPER AIR OBSERVATIONS AND MODEL ANALYSIS FIELDS INDICATE
CONSIDERABLY COLDER AIR ALOFT WITH THIS SYSTEM...PUSHING -20C AT 500
MB...THAT WILL BE CARRIED OVER LOWER MICHIGAN DURING DAYTIME
HEATING. IN ADDITION...THE WAVE ITSELF WILL FEED OFF CONTINUED LONG
WAVE AMPLIFICATION AND 100 KT UPPER JET AXIS FOR STRENGTHENING
DYNAMIC SUPPORT OF LARGE SCALE LIFT. IT`S NO SURPRISE THAT MODEL
SOUNDINGS CARRY AN UNSTABLE PROFILE THROUGH THE NIGHT AND SUNDAY
MORNING AS 0-6KM BULK SHEAR RISES TO 50 KNOTS. AN IMPORTANT
DIFFERENCE AMONG THE INDIVIDUAL SOLUTIONS IS IN THE HANDLING OF
BOUNDARY LAYER MOISTURE AND THE RESULTING CAPE PROFILE AS THE COLD
CORE ALOFT MOVES OVERHEAD. THE NAM IS ALONE IN MAINTAINING SURFACE
DEWPOINT IN THE UPPER 60S WITH LITTLE OR NO DRY AIR ADVECTION BEHIND
THE PREFRONTAL TROUGH DRIVING TODAY`S ACTIVITY. THE RESULT IS
SURFACE BASED CAPE NEAR 1500 J/KG BY 15Z ON EARLY DAY MAX TEMPS IN
THE UPPER 60S TO LOWER 70S WHILE THE GFS, ECMWF, AND MOST OF THE
LATEST SREF MEMBERS DROP CAPE BELOW 1000 J/KG WITH SURFACE DEWPOINT
IN THE UPPER 50S TO PERHAPS LOWER 60S OVER THE FAR SOUTHEAST.
HOWEVER...THERE IS SOME MERIT TO THE NAM SOLUTION AS SURFACE
PRESSURE FALLS OVER THE UPPER MIDWEST ELONGATE THE PRIMARY SURFACE
TROUGH ENOUGH TO ALTER THE DOWNSTREAM WIND PATTERN AND POSSIBLY
STALL THE EXIT OF THE LOW LEVEL THETA-E RIDGE AND/OR SIPHON SOME
EXTRA MOISTURE WESTWARD. AT THIS POINT...IT SEEMS PRUDENT TO MAKE
THE SYSTEM PROVE IT WON`T OVERACHIEVE. THEREFORE...LIKELY POPS FOR
SHOWERS WITH A CHANCE OF THUNDERSTORMS WILL BE MAINTAINED IN THE
FORECAST. CONVECTIVE ORGANIZATION WILL STRONGLY DEPEND ON THE
EVENTUAL AMOUNT OF INSTABILITY AVAILABLE TO GO ALONG WITH THE STRONG
WIND FIELD. STORMS HAVE THE POTENTIAL FOR STRONG WIND GUSTS AND
SMALL HAIL GIVEN THE COLD CORE ALOFT AND LOW FREEZING LEVEL.

THE SUNDAY SYSTEM WILL EXIT THE GREAT LAKES QUICKLY BY EVENING AND
OPEN THE DOOR FOR COOLER AIR TO SPREAD OVER THE REGION THROUGH
SUNDAY NIGHT. STRONG LOW LEVEL COLD ADVECTION SHOWN IN ALL MODEL
SOLUTIONS WILL CARRY 850 MB TEMPS DOWN INTO THE SINGLE DIGITS BY
MONDAY MORNING ON ROBUST NORTHERLY FLOW. THIS WILL CONFINE MAX TEMPS
TO THE LOWER HALF OF THE 60S...AND LIKELY LIMIT TO UPPER 50S NEAR
THE LAKE HURON SHORELINE.

GLOBAL MODEL SOLUTIONS ARE STABLE ON THE LONG WAVE UPPER LEVEL
PATTERN DURING MID WEEK. A FULL LATITUDE TROUGH OFF THE PACIFIC
COAST WILL ANCHOR A BROAD/DEAMPLIFIED RIDGE OVER MUCH OF NORTH
AMERICA AS THE EASTERN CANADIAN UPPER TROUGH MOVES TOWARD THE NORTH
ATLANTIC. THE BROAD NATURE OF THE RIDGE WILL ALLOW A SLOW ABSORPTION
OF THE CALIFORNIA CLOSED LOW BACK INTO THE WESTERLIES AND AN EQUALLY
SLOW MIGRATION INTO THE PLAINS. THE PRIMARY IMPACT THIS HAS ON THE
FORECAST FOR SE MICHIGAN IS RELATED TO AN EASTWARD DISPLACEMENT OF
NORTHWEST FLOW ALOFT AND A LESS AGGRESSIVE BACKDOOR SURFACE FRONT
INTO THE GREAT LAKES TUESDAY. THIS WAS A BENIGN FEATURE IN PREVIOUS
MODEL RUNS AND IS RENDERED EVEN MORE SO ON THE BACKGROUND OF THE
LATEST DEPICTIONS OF LARGE SCALE PATTERN EVOLUTION. THE END RESULT
WILL BE A RESURGENCE OF SURFACE HIGH PRESSURE THROUGH THE MID WEEK
PERIOD THAT WILL SUPPORT DRY WEATHER WITH NEAR NORMAL TEMPERATURES
UNTIL POSSIBLY FRIDAY WHEN REMNANTS OF THE PLAINS SHORT WAVE COULD
BRING A LOW CHANCE OF RAIN.

MARINE...

SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH TODAY FOR SAGINAW
BAY AROUND THE TIP OF THE THUMB. THIS IS WHERE SOUTHWEST FLOW WILL
BE STRONGEST AS IT CHANNELS DOWN THE BAY AND ALONG THE THUMB
SHORELINE. CONDITIONS WILL BECOME INCREASINGLY UNSETTLED ACROSS ALL
MARINE AREAS AS A PATTERN OF SHOWERS AND THUNDERSTORMS DEVELOPS AND
MOVES ACROSS THE REGION DURING THE AFTERNOON AND TONIGHT. ADDITIONAL
SHOWERS AND STORMS ARE THEN POSSIBLE WITH THE PRIMARY COLD FRONT
THAT WILL SHIFT THE WIND TOWARD THE NORTH SUNDAY AND SUNDAY NIGHT
THROUGH MONDAY. SMALL CRAFT ADVISORIES MAY BE NEEDED AGAIN FOR THE
LARGE WAVE RESPONSE ON THE SOUTH HALF OF LAKE HURON. HIGH PRESSURE
WILL EXERT FAVORABLE INFLUENCE ON THE WATERS DURING THE MIDDLE OF
NEXT WEEK.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
     PORT AUSTIN TO HARBOR BEACH...UNTIL 8 PM SATURDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....DG
SHORT TERM...JVC
LONG TERM....BT
MARINE.......BT


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







000
FXUS63 KDTX 201103
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
703 AM EDT SAT SEP 20 2014

.AVIATION...

//DISCUSSION...

THE BROKEN LINE OF SHOWERS AND THUNDERSTORMS BETWEEN GRR AND FNT
AT PRESS TIME IS ASSOCIATED WITH THE LEADING EDGE OF WARMER AND
MORE HUMID AIR ALOFT THAT WILL CONTINUE TO MAKE INROADS OVER LOWER
MICHIGAN DURING THE MORNING. THE MORNING ACTIVITY IS STILL
EXPECTED TO FADE IN FAVOR OF REDEVELOPMENT DURING THE AFTERNOON
AND EVENING. STRENGTHENING SW GRADIENT AND WELL-MIXED CONDITIONS
WILL SUPPORT GUSTS OF 20 TO 25 KNOTS THROUGH THE DAYTIME HOURS AND
CONTINUE TO CARRY LOW LEVEL MOISTURE INTO THE AREA. BOUNDARY
LAYER GROWTH WILL SUPPORT AT LEAST SCT COVERAGE OF DIURNAL CU
AROUND 4KFT DURING THE EARLY AFTERNOON. A LINE OF TSRA IS THEN
FORECAST TO DEVELOP UPSTREAM AHEAD OF AN APPROACHING WAVE AND
MIGRATE INTO THE AREA AFTER 18Z. IT STILL APPEARS THAT INSTABILITY
WILL BE BEST ACROSS THE NW HALF OF THE AREA, SO CONTINUED OMISSION
OF TSRA FOR THE DETROIT AREA SITES. A TEMPO TSRA IS NOW INCLUDED
FOR KMBS/KFNT/KPTK WITH JUST SHRA AND MVFR VSBY FOR THE DETROIT
AREA. TSTORM REDEVELOPMENT WILL BE POSSIBLE LATE TONIGHT AS INFLUX
OF MID-LEVEL COLD AIR MAINTAINS INSTABILITY OVER THE REGION.
CONFIDENCE REMAINS FAR TOO LOW TO INCLUDE IN THE TAFS ATTM...SO
OPTED TO REPRESENT POTENTIAL WITH REINTRODUCTION OF SHRA BY 08Z.
MVFR CEILING EXPECTED TO BE IN PLACE AT ALL LOCATIONS BY LATE
TONIGHT.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE THAT A TSTORM WILL IMPACT KDTW TODAY/TONIGHT

* LOW CONFIDENCE IN CEILINGS BELOW 5KFT TODAY, MEDIUM CONFIDENCE TONIGHT

&&

.PREV DISCUSSION...ISSUED 405 AM EDT SAT SEP 20 2014

SHORT TERM...TODAY AND TONIGHT

TODAY. CONVECTION IS ONGOING WITHIN THE UPSTREAM THETA-E AXIS THAT
HAS BEEN DRAWN INTO THE UPPER MS VALLEY AHEAD OF THE BROAD CORRIDOR
OF HEIGHT FALLS SPREADING INTO THE NORTHERN U.S. CONVECTIVE DEBRIS
OVER IA/WI/IL WILL SPREAD EAST NORTHEAST DURING THE MORNING,
ENGULFING MOST OR ALL OF THE FORECAST AREA BY EARLY AFTN. SUBSEQUENT
LIMITED INSOLATION WILL RESULT IN SUSPECT PROSPECTS FOR INSTABILITY
TODAY AS THE THETA-E AXIS FOLDS EAST AND INTO THE AREA. 00Z NAM/RAP
DO STILL SUGGEST A RIBBON OF 1000 J/KG ADVECTING INTO NORTHWEST HALF
OF THE CWA DURING THE AFTERNOON, A REASONABLE PROSPECT GIVEN THE
HEALTHY SOUTHWEST GRADIENT FLOW. IN ADDITION, THE 00Z SUITE HAVE PICKED
UP ON THE POTENT LOW AMPLITUDE SHORTWAVE SEEN DIVING SOUTHEAST OUT OF
MONTANA AT 06Z THIS MORNING. THIS WAVE WAS EITHER UNDERSIMULATED OR
NON-EXISTENT IN THE 12Z GUIDANCE, AND THE MOST RECENT SIMULATIONS
SUGGEST THAT IT WILL BE SUFFICIENTLY STRONG TO INITIATE CONVECTION
ACROSS WESTERN LOWER MI THIS AFTERNOON. 0-6KM SHEAR ON THE ORDER OF
35 KTS FUELED BY A MODERATE SWLY LOW-LEVEL JET WILL BE SUFFICIENT
FOR ORGANIZATION OF THE STRONGEST UPDRAFTS. BUT GENERALLY SPEAKING,
MARGINAL INSTABILITY/LOW CAPE DENSITY WILL BE RESTRICTIVE OF SEVERE
CONVECTION. EXPECT NOTHING MORE THAN A MARGINAL SEVERE WIND/HAIL
THREAT THIS AFTERNOON, MAINLY FOCUSED ACROSS THE NORTHWESTERN HALF
OF THE AREA WHERE CONVECTIVE POTENTIAL WILL MOST FAVORABLY COINCIDE
WITH PEAK HEATING. AFOREMENTIONED SWLY GRADIENT AND WELL-MIXED
BOUNDARY LAYER TO AROUND 875MB WILL RESULT WARM/GUSTY DAY WITH HIGHS
OF 75 TO 80 AND WIND GUSTS TO 25 MPH.

TONIGHT. CYCLONIC SHEAR MAX ALONG THE COLD SIDE OF THE 120KT DIVING
OUT OF CANADA THIS MORNING WILL UNDERGO CONSIDERABLE AMPLIFICATION
AS IT APPROACHES THE GREAT LAKES TONIGHT. SOUTHWESTERLY ADVECTION OF
WARMER LOW-LEVEL AIR AND RAPIDLY COOLING HEIGHTS ALOFT WILL MAINTAIN
1000 TO 2000 J/KG OF CAPE FOR THE BALANCE OF THE NIGHT. AT THE SAME
TIME, THE RAPIDLY TIGHTENING MASS GRADIENT WILL ALLOW A 70 KNOT H5
JET TO IMPINGE ON THE FORECAST AREA RESULTING IN A 0-6KM BULK SHEAR
SOLIDLY IN 60-70 KNOT RANGE BY AROUND 09Z. MEANWHILE, THE LOW-LEVEL
WIND RESPONSE WILL FACILITATE A SECOND THETA-E SURGE INTO THE AREA
POST-06Z WITHIN A BAND OF INCREASING 300-310K SYSTEM RELATIVE
ISENTROPIC ASCENT. IN THE PRESENCE OF INCREASING LARGE SCALE ASCENT,
THIS WILL BE SUPPORTIVE OF ADDITIONAL CONVECTIVE DEVELOPMENT OVER
THE AREA LATE TONIGHT. GIVEN THE PARAMETERS, THE POTENTIAL FOR
MESOCYCLONE DEVELOPMENT AND A SUBSEQUENT SEVERE RISK IS READILY
EVIDENT. HOWEVER, MODELED SOUNDINGS ONCE AGAIN SUGGEST A RATHER LOW
CAPE DENSITY WHICH, GIVEN THE MAGNITUDE OF MID-LEVEL WINDS, MAY
SIMPLY RESULT IN DECAPITATION OF UPDRAFTS AT 15KFT OR SO. THE NATURE
OF TONIGHT`S INSTABILITY PROFILE WILL BE A KEY HERE, BUT ATTM IT
APPEARS LESS IMPRESSIVE IN REALITY THAN IT DOES IN PARAMETER SPACE.
NONETHELESS, OBVIOUSLY CAN`T COMPLETELY RULE OUT SEVERE RISK IN THIS
TYPE OF ENVIRONMENT. THE BEST CHANCE FOR SEVERE WIND/HAIL THREAT
WILL MOST LIKELY LIE ALONG THE EHI MAX WHICH IS CURRENTLY PROGGED TO
ALIGN ALONG/NORTH OF M59, BUT ALL AREAS WILL CARRY AT LEAST A LOW
SLIGHT RISK THROUGH 12Z.

LONG TERM...

THE NEXT SHORT WAVE WILL BE CLOSE ON THE HEELS OF TODAY`S SYSTEM AND
ARRIVE IN TIME TO BRING UNSETTLED WEATHER IN SE MICHIGAN FOR MUCH OF
SUNDAY. THE SYSTEM IS INDICATED IN MORNING SATELLITE IMAGERY MOVING
THROUGH CENTRAL CANADA AND DISPLAYS BOTH ENERGETIC CIRCULATION AND
TEXTURE/CONVECTION IN SUPPORT OF DEPICTIONS IN THE NEW MODEL CYCLE.
UPPER AIR OBSERVATIONS AND MODEL ANALYSIS FIELDS INDICATE
CONSIDERABLY COLDER AIR ALOFT WITH THIS SYSTEM...PUSHING -20C AT 500
MB...THAT WILL BE CARRIED OVER LOWER MICHIGAN DURING DAYTIME
HEATING. IN ADDITION...THE WAVE ITSELF WILL FEED OFF CONTINUED LONG
WAVE AMPLIFICATION AND 100 KT UPPER JET AXIS FOR STRENGTHENING
DYNAMIC SUPPORT OF LARGE SCALE LIFT. IT`S NO SURPRISE THAT MODEL
SOUNDINGS CARRY AN UNSTABLE PROFILE THROUGH THE NIGHT AND SUNDAY
MORNING AS 0-6KM BULK SHEAR RISES TO 50 KNOTS. AN IMPORTANT
DIFFERENCE AMONG THE INDIVIDUAL SOLUTIONS IS IN THE HANDLING OF
BOUNDARY LAYER MOISTURE AND THE RESULTING CAPE PROFILE AS THE COLD
CORE ALOFT MOVES OVERHEAD. THE NAM IS ALONE IN MAINTAINING SURFACE
DEWPOINT IN THE UPPER 60S WITH LITTLE OR NO DRY AIR ADVECTION BEHIND
THE PREFRONTAL TROUGH DRIVING TODAY`S ACTIVITY. THE RESULT IS
SURFACE BASED CAPE NEAR 1500 J/KG BY 15Z ON EARLY DAY MAX TEMPS IN
THE UPPER 60S TO LOWER 70S WHILE THE GFS, ECMWF, AND MOST OF THE
LATEST SREF MEMBERS DROP CAPE BELOW 1000 J/KG WITH SURFACE DEWPOINT
IN THE UPPER 50S TO PERHAPS LOWER 60S OVER THE FAR SOUTHEAST.
HOWEVER...THERE IS SOME MERIT TO THE NAM SOLUTION AS SURFACE
PRESSURE FALLS OVER THE UPPER MIDWEST ELONGATE THE PRIMARY SURFACE
TROUGH ENOUGH TO ALTER THE DOWNSTREAM WIND PATTERN AND POSSIBLY
STALL THE EXIT OF THE LOW LEVEL THETA-E RIDGE AND/OR SIPHON SOME
EXTRA MOISTURE WESTWARD. AT THIS POINT...IT SEEMS PRUDENT TO MAKE
THE SYSTEM PROVE IT WON`T OVERACHIEVE. THEREFORE...LIKELY POPS FOR
SHOWERS WITH A CHANCE OF THUNDERSTORMS WILL BE MAINTAINED IN THE
FORECAST. CONVECTIVE ORGANIZATION WILL STRONGLY DEPEND ON THE
EVENTUAL AMOUNT OF INSTABILITY AVAILABLE TO GO ALONG WITH THE STRONG
WIND FIELD. STORMS HAVE THE POTENTIAL FOR STRONG WIND GUSTS AND
SMALL HAIL GIVEN THE COLD CORE ALOFT AND LOW FREEZING LEVEL.

THE SUNDAY SYSTEM WILL EXIT THE GREAT LAKES QUICKLY BY EVENING AND
OPEN THE DOOR FOR COOLER AIR TO SPREAD OVER THE REGION THROUGH
SUNDAY NIGHT. STRONG LOW LEVEL COLD ADVECTION SHOWN IN ALL MODEL
SOLUTIONS WILL CARRY 850 MB TEMPS DOWN INTO THE SINGLE DIGITS BY
MONDAY MORNING ON ROBUST NORTHERLY FLOW. THIS WILL CONFINE MAX TEMPS
TO THE LOWER HALF OF THE 60S...AND LIKELY LIMIT TO UPPER 50S NEAR
THE LAKE HURON SHORELINE.

GLOBAL MODEL SOLUTIONS ARE STABLE ON THE LONG WAVE UPPER LEVEL
PATTERN DURING MID WEEK. A FULL LATITUDE TROUGH OFF THE PACIFIC
COAST WILL ANCHOR A BROAD/DEAMPLIFIED RIDGE OVER MUCH OF NORTH
AMERICA AS THE EASTERN CANADIAN UPPER TROUGH MOVES TOWARD THE NORTH
ATLANTIC. THE BROAD NATURE OF THE RIDGE WILL ALLOW A SLOW ABSORPTION
OF THE CALIFORNIA CLOSED LOW BACK INTO THE WESTERLIES AND AN EQUALLY
SLOW MIGRATION INTO THE PLAINS. THE PRIMARY IMPACT THIS HAS ON THE
FORECAST FOR SE MICHIGAN IS RELATED TO AN EASTWARD DISPLACEMENT OF
NORTHWEST FLOW ALOFT AND A LESS AGGRESSIVE BACKDOOR SURFACE FRONT
INTO THE GREAT LAKES TUESDAY. THIS WAS A BENIGN FEATURE IN PREVIOUS
MODEL RUNS AND IS RENDERED EVEN MORE SO ON THE BACKGROUND OF THE
LATEST DEPICTIONS OF LARGE SCALE PATTERN EVOLUTION. THE END RESULT
WILL BE A RESURGENCE OF SURFACE HIGH PRESSURE THROUGH THE MID WEEK
PERIOD THAT WILL SUPPORT DRY WEATHER WITH NEAR NORMAL TEMPERATURES
UNTIL POSSIBLY FRIDAY WHEN REMNANTS OF THE PLAINS SHORT WAVE COULD
BRING A LOW CHANCE OF RAIN.

MARINE...

SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH TODAY FOR SAGINAW
BAY AROUND THE TIP OF THE THUMB. THIS IS WHERE SOUTHWEST FLOW WILL
BE STRONGEST AS IT CHANNELS DOWN THE BAY AND ALONG THE THUMB
SHORELINE. CONDITIONS WILL BECOME INCREASINGLY UNSETTLED ACROSS ALL
MARINE AREAS AS A PATTERN OF SHOWERS AND THUNDERSTORMS DEVELOPS AND
MOVES ACROSS THE REGION DURING THE AFTERNOON AND TONIGHT. ADDITIONAL
SHOWERS AND STORMS ARE THEN POSSIBLE WITH THE PRIMARY COLD FRONT
THAT WILL SHIFT THE WIND TOWARD THE NORTH SUNDAY AND SUNDAY NIGHT
THROUGH MONDAY. SMALL CRAFT ADVISORIES MAY BE NEEDED AGAIN FOR THE
LARGE WAVE RESPONSE ON THE SOUTH HALF OF LAKE HURON. HIGH PRESSURE
WILL EXERT FAVORABLE INFLUENCE ON THE WATERS DURING THE MIDDLE OF
NEXT WEEK.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
     PORT AUSTIN TO HARBOR BEACH...UNTIL 8 PM SATURDAY.

LAKE ST CLAIR...NONE.

MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....JVC
SHORT TERM...JVC
LONG TERM....BT
MARINE.......BT


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).









000
FXUS63 KDTX 201103
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
703 AM EDT SAT SEP 20 2014

.AVIATION...

//DISCUSSION...

THE BROKEN LINE OF SHOWERS AND THUNDERSTORMS BETWEEN GRR AND FNT
AT PRESS TIME IS ASSOCIATED WITH THE LEADING EDGE OF WARMER AND
MORE HUMID AIR ALOFT THAT WILL CONTINUE TO MAKE INROADS OVER LOWER
MICHIGAN DURING THE MORNING. THE MORNING ACTIVITY IS STILL
EXPECTED TO FADE IN FAVOR OF REDEVELOPMENT DURING THE AFTERNOON
AND EVENING. STRENGTHENING SW GRADIENT AND WELL-MIXED CONDITIONS
WILL SUPPORT GUSTS OF 20 TO 25 KNOTS THROUGH THE DAYTIME HOURS AND
CONTINUE TO CARRY LOW LEVEL MOISTURE INTO THE AREA. BOUNDARY
LAYER GROWTH WILL SUPPORT AT LEAST SCT COVERAGE OF DIURNAL CU
AROUND 4KFT DURING THE EARLY AFTERNOON. A LINE OF TSRA IS THEN
FORECAST TO DEVELOP UPSTREAM AHEAD OF AN APPROACHING WAVE AND
MIGRATE INTO THE AREA AFTER 18Z. IT STILL APPEARS THAT INSTABILITY
WILL BE BEST ACROSS THE NW HALF OF THE AREA, SO CONTINUED OMISSION
OF TSRA FOR THE DETROIT AREA SITES. A TEMPO TSRA IS NOW INCLUDED
FOR KMBS/KFNT/KPTK WITH JUST SHRA AND MVFR VSBY FOR THE DETROIT
AREA. TSTORM REDEVELOPMENT WILL BE POSSIBLE LATE TONIGHT AS INFLUX
OF MID-LEVEL COLD AIR MAINTAINS INSTABILITY OVER THE REGION.
CONFIDENCE REMAINS FAR TOO LOW TO INCLUDE IN THE TAFS ATTM...SO
OPTED TO REPRESENT POTENTIAL WITH REINTRODUCTION OF SHRA BY 08Z.
MVFR CEILING EXPECTED TO BE IN PLACE AT ALL LOCATIONS BY LATE
TONIGHT.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE THAT A TSTORM WILL IMPACT KDTW TODAY/TONIGHT

* LOW CONFIDENCE IN CEILINGS BELOW 5KFT TODAY, MEDIUM CONFIDENCE TONIGHT

&&

.PREV DISCUSSION...ISSUED 405 AM EDT SAT SEP 20 2014

SHORT TERM...TODAY AND TONIGHT

TODAY. CONVECTION IS ONGOING WITHIN THE UPSTREAM THETA-E AXIS THAT
HAS BEEN DRAWN INTO THE UPPER MS VALLEY AHEAD OF THE BROAD CORRIDOR
OF HEIGHT FALLS SPREADING INTO THE NORTHERN U.S. CONVECTIVE DEBRIS
OVER IA/WI/IL WILL SPREAD EAST NORTHEAST DURING THE MORNING,
ENGULFING MOST OR ALL OF THE FORECAST AREA BY EARLY AFTN. SUBSEQUENT
LIMITED INSOLATION WILL RESULT IN SUSPECT PROSPECTS FOR INSTABILITY
TODAY AS THE THETA-E AXIS FOLDS EAST AND INTO THE AREA. 00Z NAM/RAP
DO STILL SUGGEST A RIBBON OF 1000 J/KG ADVECTING INTO NORTHWEST HALF
OF THE CWA DURING THE AFTERNOON, A REASONABLE PROSPECT GIVEN THE
HEALTHY SOUTHWEST GRADIENT FLOW. IN ADDITION, THE 00Z SUITE HAVE PICKED
UP ON THE POTENT LOW AMPLITUDE SHORTWAVE SEEN DIVING SOUTHEAST OUT OF
MONTANA AT 06Z THIS MORNING. THIS WAVE WAS EITHER UNDERSIMULATED OR
NON-EXISTENT IN THE 12Z GUIDANCE, AND THE MOST RECENT SIMULATIONS
SUGGEST THAT IT WILL BE SUFFICIENTLY STRONG TO INITIATE CONVECTION
ACROSS WESTERN LOWER MI THIS AFTERNOON. 0-6KM SHEAR ON THE ORDER OF
35 KTS FUELED BY A MODERATE SWLY LOW-LEVEL JET WILL BE SUFFICIENT
FOR ORGANIZATION OF THE STRONGEST UPDRAFTS. BUT GENERALLY SPEAKING,
MARGINAL INSTABILITY/LOW CAPE DENSITY WILL BE RESTRICTIVE OF SEVERE
CONVECTION. EXPECT NOTHING MORE THAN A MARGINAL SEVERE WIND/HAIL
THREAT THIS AFTERNOON, MAINLY FOCUSED ACROSS THE NORTHWESTERN HALF
OF THE AREA WHERE CONVECTIVE POTENTIAL WILL MOST FAVORABLY COINCIDE
WITH PEAK HEATING. AFOREMENTIONED SWLY GRADIENT AND WELL-MIXED
BOUNDARY LAYER TO AROUND 875MB WILL RESULT WARM/GUSTY DAY WITH HIGHS
OF 75 TO 80 AND WIND GUSTS TO 25 MPH.

TONIGHT. CYCLONIC SHEAR MAX ALONG THE COLD SIDE OF THE 120KT DIVING
OUT OF CANADA THIS MORNING WILL UNDERGO CONSIDERABLE AMPLIFICATION
AS IT APPROACHES THE GREAT LAKES TONIGHT. SOUTHWESTERLY ADVECTION OF
WARMER LOW-LEVEL AIR AND RAPIDLY COOLING HEIGHTS ALOFT WILL MAINTAIN
1000 TO 2000 J/KG OF CAPE FOR THE BALANCE OF THE NIGHT. AT THE SAME
TIME, THE RAPIDLY TIGHTENING MASS GRADIENT WILL ALLOW A 70 KNOT H5
JET TO IMPINGE ON THE FORECAST AREA RESULTING IN A 0-6KM BULK SHEAR
SOLIDLY IN 60-70 KNOT RANGE BY AROUND 09Z. MEANWHILE, THE LOW-LEVEL
WIND RESPONSE WILL FACILITATE A SECOND THETA-E SURGE INTO THE AREA
POST-06Z WITHIN A BAND OF INCREASING 300-310K SYSTEM RELATIVE
ISENTROPIC ASCENT. IN THE PRESENCE OF INCREASING LARGE SCALE ASCENT,
THIS WILL BE SUPPORTIVE OF ADDITIONAL CONVECTIVE DEVELOPMENT OVER
THE AREA LATE TONIGHT. GIVEN THE PARAMETERS, THE POTENTIAL FOR
MESOCYCLONE DEVELOPMENT AND A SUBSEQUENT SEVERE RISK IS READILY
EVIDENT. HOWEVER, MODELED SOUNDINGS ONCE AGAIN SUGGEST A RATHER LOW
CAPE DENSITY WHICH, GIVEN THE MAGNITUDE OF MID-LEVEL WINDS, MAY
SIMPLY RESULT IN DECAPITATION OF UPDRAFTS AT 15KFT OR SO. THE NATURE
OF TONIGHT`S INSTABILITY PROFILE WILL BE A KEY HERE, BUT ATTM IT
APPEARS LESS IMPRESSIVE IN REALITY THAN IT DOES IN PARAMETER SPACE.
NONETHELESS, OBVIOUSLY CAN`T COMPLETELY RULE OUT SEVERE RISK IN THIS
TYPE OF ENVIRONMENT. THE BEST CHANCE FOR SEVERE WIND/HAIL THREAT
WILL MOST LIKELY LIE ALONG THE EHI MAX WHICH IS CURRENTLY PROGGED TO
ALIGN ALONG/NORTH OF M59, BUT ALL AREAS WILL CARRY AT LEAST A LOW
SLIGHT RISK THROUGH 12Z.

LONG TERM...

THE NEXT SHORT WAVE WILL BE CLOSE ON THE HEELS OF TODAY`S SYSTEM AND
ARRIVE IN TIME TO BRING UNSETTLED WEATHER IN SE MICHIGAN FOR MUCH OF
SUNDAY. THE SYSTEM IS INDICATED IN MORNING SATELLITE IMAGERY MOVING
THROUGH CENTRAL CANADA AND DISPLAYS BOTH ENERGETIC CIRCULATION AND
TEXTURE/CONVECTION IN SUPPORT OF DEPICTIONS IN THE NEW MODEL CYCLE.
UPPER AIR OBSERVATIONS AND MODEL ANALYSIS FIELDS INDICATE
CONSIDERABLY COLDER AIR ALOFT WITH THIS SYSTEM...PUSHING -20C AT 500
MB...THAT WILL BE CARRIED OVER LOWER MICHIGAN DURING DAYTIME
HEATING. IN ADDITION...THE WAVE ITSELF WILL FEED OFF CONTINUED LONG
WAVE AMPLIFICATION AND 100 KT UPPER JET AXIS FOR STRENGTHENING
DYNAMIC SUPPORT OF LARGE SCALE LIFT. IT`S NO SURPRISE THAT MODEL
SOUNDINGS CARRY AN UNSTABLE PROFILE THROUGH THE NIGHT AND SUNDAY
MORNING AS 0-6KM BULK SHEAR RISES TO 50 KNOTS. AN IMPORTANT
DIFFERENCE AMONG THE INDIVIDUAL SOLUTIONS IS IN THE HANDLING OF
BOUNDARY LAYER MOISTURE AND THE RESULTING CAPE PROFILE AS THE COLD
CORE ALOFT MOVES OVERHEAD. THE NAM IS ALONE IN MAINTAINING SURFACE
DEWPOINT IN THE UPPER 60S WITH LITTLE OR NO DRY AIR ADVECTION BEHIND
THE PREFRONTAL TROUGH DRIVING TODAY`S ACTIVITY. THE RESULT IS
SURFACE BASED CAPE NEAR 1500 J/KG BY 15Z ON EARLY DAY MAX TEMPS IN
THE UPPER 60S TO LOWER 70S WHILE THE GFS, ECMWF, AND MOST OF THE
LATEST SREF MEMBERS DROP CAPE BELOW 1000 J/KG WITH SURFACE DEWPOINT
IN THE UPPER 50S TO PERHAPS LOWER 60S OVER THE FAR SOUTHEAST.
HOWEVER...THERE IS SOME MERIT TO THE NAM SOLUTION AS SURFACE
PRESSURE FALLS OVER THE UPPER MIDWEST ELONGATE THE PRIMARY SURFACE
TROUGH ENOUGH TO ALTER THE DOWNSTREAM WIND PATTERN AND POSSIBLY
STALL THE EXIT OF THE LOW LEVEL THETA-E RIDGE AND/OR SIPHON SOME
EXTRA MOISTURE WESTWARD. AT THIS POINT...IT SEEMS PRUDENT TO MAKE
THE SYSTEM PROVE IT WON`T OVERACHIEVE. THEREFORE...LIKELY POPS FOR
SHOWERS WITH A CHANCE OF THUNDERSTORMS WILL BE MAINTAINED IN THE
FORECAST. CONVECTIVE ORGANIZATION WILL STRONGLY DEPEND ON THE
EVENTUAL AMOUNT OF INSTABILITY AVAILABLE TO GO ALONG WITH THE STRONG
WIND FIELD. STORMS HAVE THE POTENTIAL FOR STRONG WIND GUSTS AND
SMALL HAIL GIVEN THE COLD CORE ALOFT AND LOW FREEZING LEVEL.

THE SUNDAY SYSTEM WILL EXIT THE GREAT LAKES QUICKLY BY EVENING AND
OPEN THE DOOR FOR COOLER AIR TO SPREAD OVER THE REGION THROUGH
SUNDAY NIGHT. STRONG LOW LEVEL COLD ADVECTION SHOWN IN ALL MODEL
SOLUTIONS WILL CARRY 850 MB TEMPS DOWN INTO THE SINGLE DIGITS BY
MONDAY MORNING ON ROBUST NORTHERLY FLOW. THIS WILL CONFINE MAX TEMPS
TO THE LOWER HALF OF THE 60S...AND LIKELY LIMIT TO UPPER 50S NEAR
THE LAKE HURON SHORELINE.

GLOBAL MODEL SOLUTIONS ARE STABLE ON THE LONG WAVE UPPER LEVEL
PATTERN DURING MID WEEK. A FULL LATITUDE TROUGH OFF THE PACIFIC
COAST WILL ANCHOR A BROAD/DEAMPLIFIED RIDGE OVER MUCH OF NORTH
AMERICA AS THE EASTERN CANADIAN UPPER TROUGH MOVES TOWARD THE NORTH
ATLANTIC. THE BROAD NATURE OF THE RIDGE WILL ALLOW A SLOW ABSORPTION
OF THE CALIFORNIA CLOSED LOW BACK INTO THE WESTERLIES AND AN EQUALLY
SLOW MIGRATION INTO THE PLAINS. THE PRIMARY IMPACT THIS HAS ON THE
FORECAST FOR SE MICHIGAN IS RELATED TO AN EASTWARD DISPLACEMENT OF
NORTHWEST FLOW ALOFT AND A LESS AGGRESSIVE BACKDOOR SURFACE FRONT
INTO THE GREAT LAKES TUESDAY. THIS WAS A BENIGN FEATURE IN PREVIOUS
MODEL RUNS AND IS RENDERED EVEN MORE SO ON THE BACKGROUND OF THE
LATEST DEPICTIONS OF LARGE SCALE PATTERN EVOLUTION. THE END RESULT
WILL BE A RESURGENCE OF SURFACE HIGH PRESSURE THROUGH THE MID WEEK
PERIOD THAT WILL SUPPORT DRY WEATHER WITH NEAR NORMAL TEMPERATURES
UNTIL POSSIBLY FRIDAY WHEN REMNANTS OF THE PLAINS SHORT WAVE COULD
BRING A LOW CHANCE OF RAIN.

MARINE...

SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH TODAY FOR SAGINAW
BAY AROUND THE TIP OF THE THUMB. THIS IS WHERE SOUTHWEST FLOW WILL
BE STRONGEST AS IT CHANNELS DOWN THE BAY AND ALONG THE THUMB
SHORELINE. CONDITIONS WILL BECOME INCREASINGLY UNSETTLED ACROSS ALL
MARINE AREAS AS A PATTERN OF SHOWERS AND THUNDERSTORMS DEVELOPS AND
MOVES ACROSS THE REGION DURING THE AFTERNOON AND TONIGHT. ADDITIONAL
SHOWERS AND STORMS ARE THEN POSSIBLE WITH THE PRIMARY COLD FRONT
THAT WILL SHIFT THE WIND TOWARD THE NORTH SUNDAY AND SUNDAY NIGHT
THROUGH MONDAY. SMALL CRAFT ADVISORIES MAY BE NEEDED AGAIN FOR THE
LARGE WAVE RESPONSE ON THE SOUTH HALF OF LAKE HURON. HIGH PRESSURE
WILL EXERT FAVORABLE INFLUENCE ON THE WATERS DURING THE MIDDLE OF
NEXT WEEK.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
     PORT AUSTIN TO HARBOR BEACH...UNTIL 8 PM SATURDAY.

LAKE ST CLAIR...NONE.

MI WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....JVC
SHORT TERM...JVC
LONG TERM....BT
MARINE.......BT


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).










000
FXUS63 KDTX 200805
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
405 AM EDT SAT SEP 20 2014

.SHORT TERM...TODAY AND TONIGHT

TODAY. CONVECTION IS ONGOING WITHIN THE UPSTREAM THETA-E AXIS THAT
HAS BEEN DRAWN INTO THE UPPER MS VALLEY AHEAD OF THE BROAD CORRIDOR
OF HEIGHT FALLS SPREADING INTO THE NORTHERN U.S. CONVECTIVE DEBRIS
OVER IA/WI/IL WILL SPREAD EAST NORTHEAST DURING THE MORNING,
ENGULFING MOST OR ALL OF THE FORECAST AREA BY EARLY AFTN. SUBSEQUENT
LIMITED INSOLATION WILL RESULT IN SUSPECT PROSPECTS FOR INSTABILITY
TODAY AS THE THETA-E AXIS FOLDS EAST AND INTO THE AREA. 00Z NAM/RAP
DO STILL SUGGEST A RIBBON OF 1000 J/KG ADVECTING INTO NORTHWEST HALF
OF THE CWA DURING THE AFTERNOON, A REASONABLE PROSPECT GIVEN THE
HEALTHY SOUTHWEST GRADIENT FLOW. IN ADDITION, THE 00Z SUITE HAVE PICKED
UP ON THE POTENT LOW AMPLITUDE SHORTWAVE SEEN DIVING SOUTHEAST OUT OF
MONTANA AT 06Z THIS MORNING. THIS WAVE WAS EITHER UNDERSIMULATED OR
NON-EXISTENT IN THE 12Z GUIDANCE, AND THE MOST RECENT SIMULATIONS
SUGGEST THAT IT WILL BE SUFFICIENTLY STRONG TO INITIATE CONVECTION
ACROSS WESTERN LOWER MI THIS AFTERNOON. 0-6KM SHEAR ON THE ORDER OF
35 KTS FUELED BY A MODERATE SWLY LOW-LEVEL JET WILL BE SUFFICIENT
FOR ORGANIZATION OF THE STRONGEST UPDRAFTS. BUT GENERALLY SPEAKING,
MARGINAL INSTABILITY/LOW CAPE DENSITY WILL BE RESTRICTIVE OF SEVERE
CONVECTION. EXPECT NOTHING MORE THAN A MARGINAL SEVERE WIND/HAIL
THREAT THIS AFTERNOON, MAINLY FOCUSED ACROSS THE NORTHWESTERN HALF
OF THE AREA WHERE CONVECTIVE POTENTIAL WILL MOST FAVORABLY COINCIDE
WITH PEAK HEATING. AFOREMENTIONED SWLY GRADIENT AND WELL-MIXED
BOUNDARY LAYER TO AROUND 875MB WILL RESULT WARM/GUSTY DAY WITH HIGHS
OF 75 TO 80 AND WIND GUSTS TO 25 MPH.


TONIGHT. CYCLONIC SHEAR MAX ALONG THE COLD SIDE OF THE 120KT DIVING
OUT OF CANADA THIS MORNING WILL UNDERGO CONSIDERABLE AMPLIFICATION
AS IT APPROACHES THE GREAT LAKES TONIGHT. SOUTHWESTERLY ADVECTION OF
WARMER LOW-LEVEL AIR AND RAPIDLY COOLING HEIGHTS ALOFT WILL MAINTAIN
1000 TO 2000 J/KG OF CAPE FOR THE BALANCE OF THE NIGHT. AT THE SAME
TIME, THE RAPIDLY TIGHTENING MASS GRADIENT WILL ALLOW A 70 KNOT H5
JET TO IMPINGE ON THE FORECAST AREA RESULTING IN A 0-6KM BULK SHEAR
SOLIDLY IN 60-70 KNOT RANGE BY AROUND 09Z. MEANWHILE, THE LOW-LEVEL
WIND RESPONSE WILL FACILITATE A SECOND THETA-E SURGE INTO THE AREA
POST-06Z WITHIN A BAND OF INCREASING 300-310K SYSTEM RELATIVE
ISENTROPIC ASCENT. IN THE PRESENCE OF INCREASING LARGE SCALE ASCENT,
THIS WILL BE SUPPORTIVE OF ADDITIONAL CONVECTIVE DEVELOPMENT OVER
THE AREA LATE TONIGHT. GIVEN THE PARAMETERS, THE POTENTIAL FOR
MESOCYCLONE DEVELOPMENT AND A SUBSEQUENT SEVERE RISK IS READILY
EVIDENT. HOWEVER, MODELED SOUNDINGS ONCE AGAIN SUGGEST A RATHER LOW
CAPE DENSITY WHICH, GIVEN THE MAGNITUDE OF MID-LEVEL WINDS, MAY
SIMPLY RESULT IN DECAPITATION OF UPDRAFTS AT 15KFT OR SO. THE NATURE
OF TONIGHT`S INSTABILITY PROFILE WILL BE A KEY HERE, BUT ATTM IT
APPEARS LESS IMPRESSIVE IN REALITY THAN IT DOES IN PARAMETER SPACE.
NONETHELESS, OBVIOUSLY CAN`T COMPLETELY RULE OUT SEVERE RISK IN THIS
TYPE OF ENVIRONMENT. THE BEST CHANCE FOR SEVERE WIND/HAIL THREAT
WILL MOST LIKELY LIE ALONG THE EHI MAX WHICH IS CURRENTLY PROGGED TO
ALIGN ALONG/NORTH OF M59, BUT ALL AREAS WILL CARRY AT LEAST A LOW
SLIGHT RISK THROUGH 12Z.

&&

.LONG TERM...

THE NEXT SHORT WAVE WILL BE CLOSE ON THE HEELS OF TODAY`S SYSTEM AND
ARRIVE IN TIME TO BRING UNSETTLED WEATHER IN SE MICHIGAN FOR MUCH OF
SUNDAY. THE SYSTEM IS INDICATED IN MORNING SATELLITE IMAGERY MOVING
THROUGH CENTRAL CANADA AND DISPLAYS BOTH ENERGETIC CIRCULATION AND
TEXTURE/CONVECTION IN SUPPORT OF DEPICTIONS IN THE NEW MODEL CYCLE.
UPPER AIR OBSERVATIONS AND MODEL ANALYSIS FIELDS INDICATE
CONSIDERABLY COLDER AIR ALOFT WITH THIS SYSTEM...PUSHING -20C AT 500
MB...THAT WILL BE CARRIED OVER LOWER MICHIGAN DURING DAYTIME
HEATING. IN ADDITION...THE WAVE ITSELF WILL FEED OFF CONTINUED LONG
WAVE AMPLIFICATION AND 100 KT UPPER JET AXIS FOR STRENGTHENING
DYNAMIC SUPPORT OF LARGE SCALE LIFT. IT`S NO SURPRISE THAT MODEL
SOUNDINGS CARRY AN UNSTABLE PROFILE THROUGH THE NIGHT AND SUNDAY
MORNING AS 0-6KM BULK SHEAR RISES TO 50 KNOTS. AN IMPORTANT
DIFFERENCE AMONG THE INDIVIDUAL SOLUTIONS IS IN THE HANDLING OF
BOUNDARY LAYER MOISTURE AND THE RESULTING CAPE PROFILE AS THE COLD
CORE ALOFT MOVES OVERHEAD. THE NAM IS ALONE IN MAINTAINING SURFACE
DEWPOINT IN THE UPPER 60S WITH LITTLE OR NO DRY AIR ADVECTION BEHIND
THE PREFRONTAL TROUGH DRIVING TODAY`S ACTIVITY. THE RESULT IS
SURFACE BASED CAPE NEAR 1500 J/KG BY 15Z ON EARLY DAY MAX TEMPS IN
THE UPPER 60S TO LOWER 70S WHILE THE GFS, ECMWF, AND MOST OF THE
LATEST SREF MEMBERS DROP CAPE BELOW 1000 J/KG WITH SURFACE DEWPOINT
IN THE UPPER 50S TO PERHAPS LOWER 60S OVER THE FAR SOUTHEAST.
HOWEVER...THERE IS SOME MERIT TO THE NAM SOLUTION AS SURFACE
PRESSURE FALLS OVER THE UPPER MIDWEST ELONGATE THE PRIMARY SURFACE
TROUGH ENOUGH TO ALTER THE DOWNSTREAM WIND PATTERN AND POSSIBLY
STALL THE EXIT OF THE LOW LEVEL THETA-E RIDGE AND/OR SIPHON SOME
EXTRA MOISTURE WESTWARD. AT THIS POINT...IT SEEMS PRUDENT TO MAKE
THE SYSTEM PROVE IT WON`T OVERACHIEVE. THEREFORE...LIKELY POPS FOR
SHOWERS WITH A CHANCE OF THUNDERSTORMS WILL BE MAINTAINED IN THE
FORECAST. CONVECTIVE ORGANIZATION WILL STRONGLY DEPEND ON THE
EVENTUAL AMOUNT OF INSTABILITY AVAILABLE TO GO ALONG WITH THE STRONG
WIND FIELD. STORMS HAVE THE POTENTIAL FOR STRONG WIND GUSTS AND
SMALL HAIL GIVEN THE COLD CORE ALOFT AND LOW FREEZING LEVEL.

THE SUNDAY SYSTEM WILL EXIT THE GREAT LAKES QUICKLY BY EVENING AND
OPEN THE DOOR FOR COOLER AIR TO SPREAD OVER THE REGION THROUGH
SUNDAY NIGHT. STRONG LOW LEVEL COLD ADVECTION SHOWN IN ALL MODEL
SOLUTIONS WILL CARRY 850 MB TEMPS DOWN INTO THE SINGLE DIGITS BY
MONDAY MORNING ON ROBUST NORTHERLY FLOW. THIS WILL CONFINE MAX TEMPS
TO THE LOWER HALF OF THE 60S...AND LIKELY LIMIT TO UPPER 50S NEAR
THE LAKE HURON SHORELINE.

GLOBAL MODEL SOLUTIONS ARE STABLE ON THE LONG WAVE UPPER LEVEL
PATTERN DURING MID WEEK. A FULL LATITUDE TROUGH OFF THE PACIFIC
COAST WILL ANCHOR A BROAD/DEAMPLIFIED RIDGE OVER MUCH OF NORTH
AMERICA AS THE EASTERN CANADIAN UPPER TROUGH MOVES TOWARD THE NORTH
ATLANTIC. THE BROAD NATURE OF THE RIDGE WILL ALLOW A SLOW ABSORPTION
OF THE CALIFORNIA CLOSED LOW BACK INTO THE WESTERLIES AND AN EQUALLY
SLOW MIGRATION INTO THE PLAINS. THE PRIMARY IMPACT THIS HAS ON THE
FORECAST FOR SE MICHIGAN IS RELATED TO AN EASTWARD DISPLACEMENT OF
NORTHWEST FLOW ALOFT AND A LESS AGGRESSIVE BACKDOOR SURFACE FRONT
INTO THE GREAT LAKES TUESDAY. THIS WAS A BENIGN FEATURE IN PREVIOUS
MODEL RUNS AND IS RENDERED EVEN MORE SO ON THE BACKGROUND OF THE
LATEST DEPICTIONS OF LARGE SCALE PATTERN EVOLUTION. THE END RESULT
WILL BE A RESURGENCE OF SURFACE HIGH PRESSURE THROUGH THE MID WEEK
PERIOD THAT WILL SUPPORT DRY WEATHER WITH NEAR NORMAL TEMPERATURES
UNTIL POSSIBLY FRIDAY WHEN REMNANTS OF THE PLAINS SHORT WAVE COULD
BRING A LOW CHANCE OF RAIN.

&&

.MARINE...

SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH TODAY FOR SAGINAW
BAY AROUND THE TIP OF THE THUMB. THIS IS WHERE SOUTHWEST FLOW WILL
BE STRONGEST AS IT CHANNELS DOWN THE BAY AND ALONG THE THUMB
SHORELINE. CONDITIONS WILL BECOME INCREASINGLY UNSETTLED ACROSS ALL
MARINE AREAS AS A PATTERN OF SHOWERS AND THUNDERSTORMS DEVELOPS AND
MOVES ACROSS THE REGION DURING THE AFTERNOON AND TONIGHT. ADDITIONAL
SHOWERS AND STORMS ARE THEN POSSIBLE WITH THE PRIMARY COLD FRONT
THAT WILL SHIFT THE WIND TOWARD THE NORTH SUNDAY AND SUNDAY NIGHT
THROUGH MONDAY. SMALL CRAFT ADVISORIES MAY BE NEEDED AGAIN FOR THE
LARGE WAVE RESPONSE ON THE SOUTH HALF OF LAKE HURON. HIGH PRESSURE
WILL EXERT FAVORABLE INFLUENCE ON THE WATERS DURING THE MIDDLE OF
NEXT WEEK.

&&

.AVIATION...ISSUED 1155 PM EDT FRI SEP 19 2014

//DISCUSSION...

CONTINUED STRENGTHENING OF THE SOUTHERLY SFC GRADIENT AND THE ONSET
OF DAYTIME HEATING LATER THIS MORNING WILL LEAD TO AN INCREASE IN
THE WINDS. GUSTS ARE EXPECTED TO TOP 20 KNOTS DURING PEAK AFTERNOON
HEATING. MID LEVEL MOISTURE ADVECTION ACROSS THE SAGINAW VALLEY THIS
MORNING MAY LEAD TO SOME HIGH BASED SHOWERS AT MBS. CONFIDENCE IS
NOT HIGH ENOUGH TO INCLUDE IN THE TAFS AT THIS TIME. STRONGER
FORCING ALONG A SFC TROUGH WILL LEAD TO A MUCH BETTER CHANCE FOR
SHOWERS AND A FEW THUNDERSTORMS LATE THIS AFTERNOON AND EVENING.

FOR DTW...THE BETTER INSTABILITY IS FORECAST TO RESIDE MAINLY NORTH
AND WEST OF METRO SAT AFTERNOON AND EVENING. THUS THE CHANCES FOR
THUNDERSTORMS IMPACTING METRO DETROIT LATE IN THE FORECAST PERIOD
ARE STILL LOW ATTM.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL FRIDAY AFTERNOON AND
FRIDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
     PORT AUSTIN TO HARBOR BEACH...UNTIL 8 PM SATURDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...JVC
LONG TERM....BT
MARINE.......BT
AVIATION.....SC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).







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