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000
FXUS63 KDTX 220142
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
942 PM EDT THU AUG 21 2014

.UPDATE...

ONGOING ACTIVITY...ROUGHLY ALONG THE I-96 CORRIDOR AT PRESS
TIME...BLOSSOMED ON THE OUTFLOW OF THE FIRST CLUSTER OF CONVECTION
THAT DISSIPATED OVER WASHTENAW COUNTY EARLIER IN THE EVENING.
EXPECT THIS SURFACE BASED ACTIVITY TO WEAKEN DURING THE LATE
EVENING AND DISSIPATE BY MIDNIGHT. NEW DEVELOPMENT WILL BE
POSSIBLE EVEN BEFORE MIDNIGHT DUE TO ELEVATED INSTABILITY BUT THIS
WILL HAVE GREATER LIKELIHOOD DURING THE OVERNIGHT HOURS THROUGH MID
FRIDAY MORNING. PERSISTENT ELEVATED INSTABILITY WILL BE TIED TO
THE MID LEVELS OF THE MAIN FRONTAL BOUNDARY STALLED OVER ILLINOIS
AND INDIANA. THE 850-500 MB THETA-E GRADIENT WILL THEN BE
MAINTAINED OVER LOWER MICHIGAN AND SUBJECT TO CONVECTIVE RESPONSE
DUE TO WEAK RIPPLES OF MOISTURE ADVECTION COMBINED WITH INCREASING
NOCTURNAL DESTABILIZATION ALOFT. THERE IS ALSO A POSSIBILITY THAT
LOW LEVEL JET FORCED STORMS COULD MAKE IT FROM WISCONSIN INTO SE
MICHIGAN TOWARD OR AFTER SUNRISE...BUT THE INSTABILITY AXIS IS
ORIENTED CLOSER TO THE SURFACE FRONT WHICH WILL MAKE IT DIFFICULT
FOR ANYTHING MORE THAN REMNANTS TO MAKE IT THIS FAR EAST THROUGH
FRIDAY MORNING.

&&

.AVIATION...ISSUED 707 PM EDT THU AUG 21 2014

//DISCUSSION...

THE PRIMARY SURFACE FRONT WILL BE STALLED TO THE SOUTH AND WEST OF
LOWER MICHIGAN TONIGHT AND FRIDAY. THIS IS EXPECTED TO KEEP THE
STRONGEST THUNDERSTORM ACTIVITY AWAY FROM THE TERMINAL SITES BUT
WITH THE POSSIBILITY OF RENEWED WEAKER ACTIVITY DEVELOPING OVERHEAD
LATER IN THE NIGHT. ANY NEW SHOWER/STORM DEVELOPMENT WILL TEND TO
COINCIDE WITH BROADER FORMATION OF MVFR CEILING AND VISIBILITY NORTH
OF THE SURFACE FRONT UP TO ABOUT PTK WITH FNT AND MBS LIKELY HAVING
JUST A FOG COMPONENT...POSSIBLY IFR DEPENDING ON HIGHER CLOUD COVER.
AS LONG AS THE SURFACE FRONT REMAINS TO OUR SOUTH...WEAK EASTERLY
FLOW FROM EQUALLY WEAK HIGH PRESSURE OVER ONTARIO WILL PROMOTE
IMPROVEMENT TO VFR BY FRIDAY AFTERNOON.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE ON THUNDERSTORM TIMING AND COVERAGE TONIGHT.

* MODERATE CONFIDENCE ON CEILING BELOW 5000 FT TONIGHT AND FRIDAY
MORNING.

&&

.PREV DISCUSSION...ISSUED 358 PM EDT THU AUG 21 2014

SHORT TERM...TONIGHT

A FEW LIGHT SHOWERS HAVE STARTED TO BUILD ACROSS SOUTHEAST
MICHIGAN...BUT HAVE FIZZLED OUT AS QUICKLY AS THEY DEVELOPED DUE TO
SIGNIFICANT AMOUNT OF SUBSIDENCE ACROSS THE REGION. NOT EXPECTING
MUCH IN THE WAY OF THUNDERSTORM DEVELOPMENT THE REST OF THE
AFTERNOON...HOWEVER A WARM FRONT ACROSS THE NORTHERN OHIO RIVER
VALLEY WILL BRING AN INCREASED CHANCE OF RAIN SHOWERS TO SOUTHEAST
MICHIGAN THIS EVENING. PRECIPITATION CHANCES WILL BEGIN NEAR THE
OHIO BORDER AND SLOWLY MOVE NORTHWARD AS THIS FRONT LIFTS SLOWLY
ACROSS THE CWA.

RAIN SHOWERS SHOULD CONTINUE OVERNIGHT AS MODELS ARE CONTINUING TO
INDICATE AN MCS /MESOSCALE CONVECTIVE SYSTEM/ TO DEVELOP OVER THE
WESTERN GREAT LAKES. THIS MCS WILL TRACK SOUTHEASTWARD TOWARDS
SOUTHEAST MICHIGAN. CURRENT THINKING IS THAT THE BULK...INCLUDING
THE MOST DAMAGING WIND GUSTS AND SEVERE POTENTIAL...OF THE MCS WILL
TRACK SOUTH OF THE CWA RESULTING IN JUST RAIN SHOWERS ACROSS
SOUTHERN MICHIGAN. HAVE LEFT IN LIKELY POPS ACROSS THE SOUTHERN TWO
TIERS OF COUNTIES TO ACCOUNT FOR ANY DEVIATION ON THE TRACK OF THE
MCS. CURRENT SPC OUTLOOK HAS PULLED BACK ON THE SLIGHT RISK ACROSS
SOUTHERN MICHIGAN...ADDING TO THE CONFIDENCE IN THE CURRENT SOUTHERN
TRACK OF THIS MCS. WITH MOST OF THE SIGNIFICANT THUNDERSTORM
DEVELOPMENT TRACKING SOUTH...THE MAJOR CONCERN FOR SOUTHEAST
MICHIGAN WILL BE THE HEAVY RAIN POTENTIAL. CURRENT MODELS ARE
SHOWING PWAT VALUES IN THE 1.5 TO 2.0 INCH RANGE. THIS WILL RESULT
IN NEARLY AN INCH OR SLIGHTLY MORE OF RAIN TO FALL OVER A SHORT
AMOUNT OF TIME. AT THIS TIME...FLOODING ISSUES ARE NOT A CONCERN.
THIS WILL HAVE TO BE MONITORED CLOSELY AS THE EVENT PROGRESSES AS
LITTLE RAIN FALLING OVER AN ALREADY SATURATED GROUND/URBAN AREAS
COULD QUICKLY RESULT IN FLOODING CONCERNS ACROSS METRO DETROIT AND
SOUTHEAST MICHIGAN.

OTHERWISE...CLOUD COVER OVERNIGHT FROM THE DEVELOPING MCS SHOULD
RESULT IN FAIRLY OVERCAST SKIES KEEPING TEMPERATURES ON THE MILD
SIDE. LOWS SHOULD BE IN THE UPPER 60S IN THE METRO DETROIT AREA AND
SLIGHTLY COOLER IN THE MID 60S ACROSS THE REST OF THE CWA. THIS IS
SLIGHTLY ABOVE AVERAGE FOR THIS TIME OF YEAR WHERE LOWS ARE NORMALLY
IN THE LOW 60S FOR DETROIT AND THE UPPER 50S FOR FLINT AND SAGINAW.

LONG TERM...

NO SUBSTANTIAL CHANGES FROM THE PREVIOUS COUPLE OF FORECAST
PACKAGES. AMPLIFICATION OF THE SUBTROPICAL RIDGE OVER THE SOUTHERN
UNITED STATES IS STILL FORECAST TO RESULT IN SIGNIFICANT WARMING OF
THE COLUMN OVER SE MICHIGAN HEADING INTO THE WEEKEND. H85 TEMPS BOTH
FRI AND SAT WILL BE PUSHING THE UPPER TEENS, WHICH WILL SUPPORT HIGH
TEMPERATURES AT LEAST IN THE LOW 80S. THERE IS SOME UNCERTAINTY
REGARDING THE POTENTIAL MIXING DEPTHS ON FRIDAY OWING TO UNCERTAIN
EVOLUTION OF TONIGHT`S CONVECTION, WHICH CORRESPONDINGLY TEMPERS
EXPECTATIONS FOR FRIDAY`S MAX TEMPS. PERHAPS THE PRIMARY REASON FOR
ABSTAINING FROM PUSHING FOR HIGHER DAYTIME HIGHS, HOWEVER, IS
ACTUALLY MORE OF A CREDIT TO EXPECTED EASTERLY WINDS AT THE SURFACE
AROUND THE SOUTHERN PERIPHERY OF HIGH PRESSURE OVER QUEBEC. THE
PREVIOUS FORECAST HANDLED THIS WELL AND NO CHANGES WERE NECESSARY.
EVEN WITH THE TEMPERED EXPECTATION FOR HIGH TEMPERATURES, THE LACK
OF ANY NOTEWORTHY EXCHANGE OF AIRMASS WILL ENSURE STICKY DEWPOINTS
IN THE MID 60S TO NEAR 70 EACH AFTERNOON. LIKEWISE, THERE REMAINS
SOME CONCERN OVER COOLING POTENTIAL AT NIGHT DUE TO ANTECEDENT MOIST
BOUNDARY LAYER CONDITIONS. AGREE WITH PREVIOUS DISCUSSION THAT THE
PRESENCE OF THETA-E GRADIENT INVOF THE LOWER PENINSULA IMMEDIATELY
DOWNSTREAM OF THE UPPER RIDGE AXIS AND RESIDENT MOIST AIRMASS MAKE
IT ESSENTIALLY IMPOSSIBLE TO RULE OUT SHOWER/T-STORMS DURING ANY ONE
PERIOD. HOWEVER, UNTIL A WELL-DEFINED OPPORTUNITY FOR DEVELOPMENT
PRESENTS ITSELF, THE BEST APPROACH REMAINS TO LEAVE THE FORECAST DRY.

SUNDAY THROUGH THURSDAY: RAIN CHANCES WILL LIKELY HANG AROUND
THROUGH MUCH OF NEXT WEEK AS A SERIES OF SHORTWAVES TRACK OVER
SOUTHEAST MICHIGAN. MODEL AGREEMENT IS STILL QUITE LOW AND HAVE
THEREFORE ONLY PUT IN LOW CHANCE POPS INTO THE FORECAST THROUGH
THURSDAY. TIMING AND COVERAGE OF THE RAIN WILL BE BETTER DEFINED
AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES. TEMPERATURES
WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S AND LOW
TEMPERATURES IN THE MID TO UPPER 60S THROUGH THE PERIOD.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME...ESPECIALLY FOR LAKE SAINT CLAIR AND LAKE ERIE. MODERATE
SOUTHEAST FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT
A MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

UPDATE.......BT
AVIATION.....BT
SHORT TERM...RK
LONG TERM....JVC/DE
MARINE.......JVC


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











000
FXUS63 KDTX 220142
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
942 PM EDT THU AUG 21 2014

.UPDATE...

ONGOING ACTIVITY...ROUGHLY ALONG THE I-96 CORRIDOR AT PRESS
TIME...BLOSSOMED ON THE OUTFLOW OF THE FIRST CLUSTER OF CONVECTION
THAT DISSIPATED OVER WASHTENAW COUNTY EARLIER IN THE EVENING.
EXPECT THIS SURFACE BASED ACTIVITY TO WEAKEN DURING THE LATE
EVENING AND DISSIPATE BY MIDNIGHT. NEW DEVELOPMENT WILL BE
POSSIBLE EVEN BEFORE MIDNIGHT DUE TO ELEVATED INSTABILITY BUT THIS
WILL HAVE GREATER LIKELIHOOD DURING THE OVERNIGHT HOURS THROUGH MID
FRIDAY MORNING. PERSISTENT ELEVATED INSTABILITY WILL BE TIED TO
THE MID LEVELS OF THE MAIN FRONTAL BOUNDARY STALLED OVER ILLINOIS
AND INDIANA. THE 850-500 MB THETA-E GRADIENT WILL THEN BE
MAINTAINED OVER LOWER MICHIGAN AND SUBJECT TO CONVECTIVE RESPONSE
DUE TO WEAK RIPPLES OF MOISTURE ADVECTION COMBINED WITH INCREASING
NOCTURNAL DESTABILIZATION ALOFT. THERE IS ALSO A POSSIBILITY THAT
LOW LEVEL JET FORCED STORMS COULD MAKE IT FROM WISCONSIN INTO SE
MICHIGAN TOWARD OR AFTER SUNRISE...BUT THE INSTABILITY AXIS IS
ORIENTED CLOSER TO THE SURFACE FRONT WHICH WILL MAKE IT DIFFICULT
FOR ANYTHING MORE THAN REMNANTS TO MAKE IT THIS FAR EAST THROUGH
FRIDAY MORNING.

&&

.AVIATION...ISSUED 707 PM EDT THU AUG 21 2014

//DISCUSSION...

THE PRIMARY SURFACE FRONT WILL BE STALLED TO THE SOUTH AND WEST OF
LOWER MICHIGAN TONIGHT AND FRIDAY. THIS IS EXPECTED TO KEEP THE
STRONGEST THUNDERSTORM ACTIVITY AWAY FROM THE TERMINAL SITES BUT
WITH THE POSSIBILITY OF RENEWED WEAKER ACTIVITY DEVELOPING OVERHEAD
LATER IN THE NIGHT. ANY NEW SHOWER/STORM DEVELOPMENT WILL TEND TO
COINCIDE WITH BROADER FORMATION OF MVFR CEILING AND VISIBILITY NORTH
OF THE SURFACE FRONT UP TO ABOUT PTK WITH FNT AND MBS LIKELY HAVING
JUST A FOG COMPONENT...POSSIBLY IFR DEPENDING ON HIGHER CLOUD COVER.
AS LONG AS THE SURFACE FRONT REMAINS TO OUR SOUTH...WEAK EASTERLY
FLOW FROM EQUALLY WEAK HIGH PRESSURE OVER ONTARIO WILL PROMOTE
IMPROVEMENT TO VFR BY FRIDAY AFTERNOON.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE ON THUNDERSTORM TIMING AND COVERAGE TONIGHT.

* MODERATE CONFIDENCE ON CEILING BELOW 5000 FT TONIGHT AND FRIDAY
MORNING.

&&

.PREV DISCUSSION...ISSUED 358 PM EDT THU AUG 21 2014

SHORT TERM...TONIGHT

A FEW LIGHT SHOWERS HAVE STARTED TO BUILD ACROSS SOUTHEAST
MICHIGAN...BUT HAVE FIZZLED OUT AS QUICKLY AS THEY DEVELOPED DUE TO
SIGNIFICANT AMOUNT OF SUBSIDENCE ACROSS THE REGION. NOT EXPECTING
MUCH IN THE WAY OF THUNDERSTORM DEVELOPMENT THE REST OF THE
AFTERNOON...HOWEVER A WARM FRONT ACROSS THE NORTHERN OHIO RIVER
VALLEY WILL BRING AN INCREASED CHANCE OF RAIN SHOWERS TO SOUTHEAST
MICHIGAN THIS EVENING. PRECIPITATION CHANCES WILL BEGIN NEAR THE
OHIO BORDER AND SLOWLY MOVE NORTHWARD AS THIS FRONT LIFTS SLOWLY
ACROSS THE CWA.

RAIN SHOWERS SHOULD CONTINUE OVERNIGHT AS MODELS ARE CONTINUING TO
INDICATE AN MCS /MESOSCALE CONVECTIVE SYSTEM/ TO DEVELOP OVER THE
WESTERN GREAT LAKES. THIS MCS WILL TRACK SOUTHEASTWARD TOWARDS
SOUTHEAST MICHIGAN. CURRENT THINKING IS THAT THE BULK...INCLUDING
THE MOST DAMAGING WIND GUSTS AND SEVERE POTENTIAL...OF THE MCS WILL
TRACK SOUTH OF THE CWA RESULTING IN JUST RAIN SHOWERS ACROSS
SOUTHERN MICHIGAN. HAVE LEFT IN LIKELY POPS ACROSS THE SOUTHERN TWO
TIERS OF COUNTIES TO ACCOUNT FOR ANY DEVIATION ON THE TRACK OF THE
MCS. CURRENT SPC OUTLOOK HAS PULLED BACK ON THE SLIGHT RISK ACROSS
SOUTHERN MICHIGAN...ADDING TO THE CONFIDENCE IN THE CURRENT SOUTHERN
TRACK OF THIS MCS. WITH MOST OF THE SIGNIFICANT THUNDERSTORM
DEVELOPMENT TRACKING SOUTH...THE MAJOR CONCERN FOR SOUTHEAST
MICHIGAN WILL BE THE HEAVY RAIN POTENTIAL. CURRENT MODELS ARE
SHOWING PWAT VALUES IN THE 1.5 TO 2.0 INCH RANGE. THIS WILL RESULT
IN NEARLY AN INCH OR SLIGHTLY MORE OF RAIN TO FALL OVER A SHORT
AMOUNT OF TIME. AT THIS TIME...FLOODING ISSUES ARE NOT A CONCERN.
THIS WILL HAVE TO BE MONITORED CLOSELY AS THE EVENT PROGRESSES AS
LITTLE RAIN FALLING OVER AN ALREADY SATURATED GROUND/URBAN AREAS
COULD QUICKLY RESULT IN FLOODING CONCERNS ACROSS METRO DETROIT AND
SOUTHEAST MICHIGAN.

OTHERWISE...CLOUD COVER OVERNIGHT FROM THE DEVELOPING MCS SHOULD
RESULT IN FAIRLY OVERCAST SKIES KEEPING TEMPERATURES ON THE MILD
SIDE. LOWS SHOULD BE IN THE UPPER 60S IN THE METRO DETROIT AREA AND
SLIGHTLY COOLER IN THE MID 60S ACROSS THE REST OF THE CWA. THIS IS
SLIGHTLY ABOVE AVERAGE FOR THIS TIME OF YEAR WHERE LOWS ARE NORMALLY
IN THE LOW 60S FOR DETROIT AND THE UPPER 50S FOR FLINT AND SAGINAW.

LONG TERM...

NO SUBSTANTIAL CHANGES FROM THE PREVIOUS COUPLE OF FORECAST
PACKAGES. AMPLIFICATION OF THE SUBTROPICAL RIDGE OVER THE SOUTHERN
UNITED STATES IS STILL FORECAST TO RESULT IN SIGNIFICANT WARMING OF
THE COLUMN OVER SE MICHIGAN HEADING INTO THE WEEKEND. H85 TEMPS BOTH
FRI AND SAT WILL BE PUSHING THE UPPER TEENS, WHICH WILL SUPPORT HIGH
TEMPERATURES AT LEAST IN THE LOW 80S. THERE IS SOME UNCERTAINTY
REGARDING THE POTENTIAL MIXING DEPTHS ON FRIDAY OWING TO UNCERTAIN
EVOLUTION OF TONIGHT`S CONVECTION, WHICH CORRESPONDINGLY TEMPERS
EXPECTATIONS FOR FRIDAY`S MAX TEMPS. PERHAPS THE PRIMARY REASON FOR
ABSTAINING FROM PUSHING FOR HIGHER DAYTIME HIGHS, HOWEVER, IS
ACTUALLY MORE OF A CREDIT TO EXPECTED EASTERLY WINDS AT THE SURFACE
AROUND THE SOUTHERN PERIPHERY OF HIGH PRESSURE OVER QUEBEC. THE
PREVIOUS FORECAST HANDLED THIS WELL AND NO CHANGES WERE NECESSARY.
EVEN WITH THE TEMPERED EXPECTATION FOR HIGH TEMPERATURES, THE LACK
OF ANY NOTEWORTHY EXCHANGE OF AIRMASS WILL ENSURE STICKY DEWPOINTS
IN THE MID 60S TO NEAR 70 EACH AFTERNOON. LIKEWISE, THERE REMAINS
SOME CONCERN OVER COOLING POTENTIAL AT NIGHT DUE TO ANTECEDENT MOIST
BOUNDARY LAYER CONDITIONS. AGREE WITH PREVIOUS DISCUSSION THAT THE
PRESENCE OF THETA-E GRADIENT INVOF THE LOWER PENINSULA IMMEDIATELY
DOWNSTREAM OF THE UPPER RIDGE AXIS AND RESIDENT MOIST AIRMASS MAKE
IT ESSENTIALLY IMPOSSIBLE TO RULE OUT SHOWER/T-STORMS DURING ANY ONE
PERIOD. HOWEVER, UNTIL A WELL-DEFINED OPPORTUNITY FOR DEVELOPMENT
PRESENTS ITSELF, THE BEST APPROACH REMAINS TO LEAVE THE FORECAST DRY.

SUNDAY THROUGH THURSDAY: RAIN CHANCES WILL LIKELY HANG AROUND
THROUGH MUCH OF NEXT WEEK AS A SERIES OF SHORTWAVES TRACK OVER
SOUTHEAST MICHIGAN. MODEL AGREEMENT IS STILL QUITE LOW AND HAVE
THEREFORE ONLY PUT IN LOW CHANCE POPS INTO THE FORECAST THROUGH
THURSDAY. TIMING AND COVERAGE OF THE RAIN WILL BE BETTER DEFINED
AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES. TEMPERATURES
WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S AND LOW
TEMPERATURES IN THE MID TO UPPER 60S THROUGH THE PERIOD.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME...ESPECIALLY FOR LAKE SAINT CLAIR AND LAKE ERIE. MODERATE
SOUTHEAST FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT
A MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

UPDATE.......BT
AVIATION.....BT
SHORT TERM...RK
LONG TERM....JVC/DE
MARINE.......JVC


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












000
FXUS63 KDTX 212307
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
707 PM EDT THU AUG 21 2014

.AVIATION...

//DISCUSSION...

THE PRIMARY SURFACE FRONT WILL BE STALLED TO THE SOUTH AND WEST OF
LOWER MICHIGAN TONIGHT AND FRIDAY. THIS IS EXPECTED TO KEEP THE
STRONGEST THUNDERSTORM ACTIVITY AWAY FROM THE TERMINAL SITES BUT
WITH THE POSSIBILITY OF RENEWED WEAKER ACTIVITY DEVELOPING OVERHEAD
LATER IN THE NIGHT. ANY NEW SHOWER/STORM DEVELOPMENT WILL TEND TO
COINCIDE WITH BROADER FORMATION OF MVFR CEILING AND VISIBILITY NORTH
OF THE SURFACE FRONT UP TO ABOUT PTK WITH FNT AND MBS LIKELY HAVING
JUST A FOG COMPONENT...POSSIBLY IFR DEPENDING ON HIGHER CLOUD COVER.
AS LONG AS THE SURFACE FRONT REMAINS TO OUR SOUTH...WEAK EASTERLY
FLOW FROM EQUALLY WEAK HIGH PRESSURE OVER ONTARIO WILL PROMOTE
IMPROVEMENT TO VFR BY FRIDAY AFTERNOON.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE ON THUNDERSTORM TIMING AND COVERAGE TONIGHT.

* MODERATE CONFIDENCE ON CEILING BELOW 5000 FT TONIGHT AND FRIDAY
MORNING.

&&

.PREV DISCUSSION...ISSUED 358 PM EDT THU AUG 21 2014

SHORT TERM...TONIGHT

A FEW LIGHT SHOWERS HAVE STARTED TO BUILD ACROSS SOUTHEAST
MICHIGAN...BUT HAVE FIZZLED OUT AS QUICKLY AS THEY DEVELOPED DUE TO
SIGNIFICANT AMOUNT OF SUBSIDENCE ACROSS THE REGION. NOT EXPECTING
MUCH IN THE WAY OF THUNDERSTORM DEVELOPMENT THE REST OF THE
AFTERNOON...HOWEVER A WARM FRONT ACROSS THE NORTHERN OHIO RIVER
VALLEY WILL BRING AN INCREASED CHANCE OF RAIN SHOWERS TO SOUTHEAST
MICHIGAN THIS EVENING. PRECIPITATION CHANCES WILL BEGIN NEAR THE
OHIO BORDER AND SLOWLY MOVE NORTHWARD AS THIS FRONT LIFTS SLOWLY
ACROSS THE CWA.

RAIN SHOWERS SHOULD CONTINUE OVERNIGHT AS MODELS ARE CONTINUING TO
INDICATE AN MCS /MESOSCALE CONVECTIVE SYSTEM/ TO DEVELOP OVER THE
WESTERN GREAT LAKES. THIS MCS WILL TRACK SOUTHEASTWARD TOWARDS
SOUTHEAST MICHIGAN. CURRENT THINKING IS THAT THE BULK...INCLUDING
THE MOST DAMAGING WIND GUSTS AND SEVERE POTENTIAL...OF THE MCS WILL
TRACK SOUTH OF THE CWA RESULTING IN JUST RAIN SHOWERS ACROSS
SOUTHERN MICHIGAN. HAVE LEFT IN LIKELY POPS ACROSS THE SOUTHERN TWO
TIERS OF COUNTIES TO ACCOUNT FOR ANY DEVIATION ON THE TRACK OF THE
MCS. CURRENT SPC OUTLOOK HAS PULLED BACK ON THE SLIGHT RISK ACROSS
SOUTHERN MICHIGAN...ADDING TO THE CONFIDENCE IN THE CURRENT SOUTHERN
TRACK OF THIS MCS. WITH MOST OF THE SIGNIFICANT THUNDERSTORM
DEVELOPMENT TRACKING SOUTH...THE MAJOR CONCERN FOR SOUTHEAST
MICHIGAN WILL BE THE HEAVY RAIN POTENTIAL. CURRENT MODELS ARE
SHOWING PWAT VALUES IN THE 1.5 TO 2.0 INCH RANGE. THIS WILL RESULT
IN NEARLY AN INCH OR SLIGHTLY MORE OF RAIN TO FALL OVER A SHORT
AMOUNT OF TIME. AT THIS TIME...FLOODING ISSUES ARE NOT A CONCERN.
THIS WILL HAVE TO BE MONITORED CLOSELY AS THE EVENT PROGRESSES AS
LITTLE RAIN FALLING OVER AN ALREADY SATURATED GROUND/URBAN AREAS
COULD QUICKLY RESULT IN FLOODING CONCERNS ACROSS METRO DETROIT AND
SOUTHEAST MICHIGAN.

OTHERWISE...CLOUD COVER OVERNIGHT FROM THE DEVELOPING MCS SHOULD
RESULT IN FAIRLY OVERCAST SKIES KEEPING TEMPERATURES ON THE MILD
SIDE. LOWS SHOULD BE IN THE UPPER 60S IN THE METRO DETROIT AREA AND
SLIGHTLY COOLER IN THE MID 60S ACROSS THE REST OF THE CWA. THIS IS
SLIGHTLY ABOVE AVERAGE FOR THIS TIME OF YEAR WHERE LOWS ARE NORMALLY
IN THE LOW 60S FOR DETROIT AND THE UPPER 50S FOR FLINT AND SAGINAW.

LONG TERM...

NO SUBSTANTIAL CHANGES FROM THE PREVIOUS COUPLE OF FORECAST
PACKAGES. AMPLIFICATION OF THE SUBTROPICAL RIDGE OVER THE SOUTHERN
UNITED STATES IS STILL FORECAST TO RESULT IN SIGNIFICANT WARMING OF
THE COLUMN OVER SE MICHIGAN HEADING INTO THE WEEKEND. H85 TEMPS BOTH
FRI AND SAT WILL BE PUSHING THE UPPER TEENS, WHICH WILL SUPPORT HIGH
TEMPERATURES AT LEAST IN THE LOW 80S. THERE IS SOME UNCERTAINTY
REGARDING THE POTENTIAL MIXING DEPTHS ON FRIDAY OWING TO UNCERTAIN
EVOLUTION OF TONIGHT`S CONVECTION, WHICH CORRESPONDINGLY TEMPERS
EXPECTATIONS FOR FRIDAY`S MAX TEMPS. PERHAPS THE PRIMARY REASON FOR
ABSTAINING FROM PUSHING FOR HIGHER DAYTIME HIGHS, HOWEVER, IS
ACTUALLY MORE OF A CREDIT TO EXPECTED EASTERLY WINDS AT THE SURFACE
AROUND THE SOUTHERN PERIPHERY OF HIGH PRESSURE OVER QUEBEC. THE
PREVIOUS FORECAST HANDLED THIS WELL AND NO CHANGES WERE NECESSARY.
EVEN WITH THE TEMPERED EXPECTATION FOR HIGH TEMPERATURES, THE LACK
OF ANY NOTEWORTHY EXCHANGE OF AIRMASS WILL ENSURE STICKY DEWPOINTS
IN THE MID 60S TO NEAR 70 EACH AFTERNOON. LIKEWISE, THERE REMAINS
SOME CONCERN OVER COOLING POTENTIAL AT NIGHT DUE TO ANTECEDENT MOIST
BOUNDARY LAYER CONDITIONS. AGREE WITH PREVIOUS DISCUSSION THAT THE
PRESENCE OF THETA-E GRADIENT INVOF THE LOWER PENINSULA IMMEDIATELY
DOWNSTREAM OF THE UPPER RIDGE AXIS AND RESIDENT MOIST AIRMASS MAKE
IT ESSENTIALLY IMPOSSIBLE TO RULE OUT SHOWER/T-STORMS DURING ANY ONE
PERIOD. HOWEVER, UNTIL A WELL-DEFINED OPPORTUNITY FOR DEVELOPMENT
PRESENTS ITSELF, THE BEST APPROACH REMAINS TO LEAVE THE FORECAST DRY.

SUNDAY THROUGH THURSDAY: RAIN CHANCES WILL LIKELY HANG AROUND
THROUGH MUCH OF NEXT WEEK AS A SERIES OF SHORTWAVES TRACK OVER
SOUTHEAST MICHIGAN. MODEL AGREEMENT IS STILL QUITE LOW AND HAVE
THEREFORE ONLY PUT IN LOW CHANCE POPS INTO THE FORECAST THROUGH
THURSDAY. TIMING AND COVERAGE OF THE RAIN WILL BE BETTER DEFINED
AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES. TEMPERATURES
WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S AND LOW
TEMPERATURES IN THE MID TO UPPER 60S THROUGH THE PERIOD.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME...ESPECIALLY FOR LAKE SAINT CLAIR AND LAKE ERIE. MODERATE
SOUTHEAST FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT
A MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

AVIATION.....BT
SHORT TERM...RK
LONG TERM....JVC/DE
MARINE.......JVC


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











000
FXUS63 KDTX 212307
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
707 PM EDT THU AUG 21 2014

.AVIATION...

//DISCUSSION...

THE PRIMARY SURFACE FRONT WILL BE STALLED TO THE SOUTH AND WEST OF
LOWER MICHIGAN TONIGHT AND FRIDAY. THIS IS EXPECTED TO KEEP THE
STRONGEST THUNDERSTORM ACTIVITY AWAY FROM THE TERMINAL SITES BUT
WITH THE POSSIBILITY OF RENEWED WEAKER ACTIVITY DEVELOPING OVERHEAD
LATER IN THE NIGHT. ANY NEW SHOWER/STORM DEVELOPMENT WILL TEND TO
COINCIDE WITH BROADER FORMATION OF MVFR CEILING AND VISIBILITY NORTH
OF THE SURFACE FRONT UP TO ABOUT PTK WITH FNT AND MBS LIKELY HAVING
JUST A FOG COMPONENT...POSSIBLY IFR DEPENDING ON HIGHER CLOUD COVER.
AS LONG AS THE SURFACE FRONT REMAINS TO OUR SOUTH...WEAK EASTERLY
FLOW FROM EQUALLY WEAK HIGH PRESSURE OVER ONTARIO WILL PROMOTE
IMPROVEMENT TO VFR BY FRIDAY AFTERNOON.

//DTW THRESHOLD THREATS...

* LOW CONFIDENCE ON THUNDERSTORM TIMING AND COVERAGE TONIGHT.

* MODERATE CONFIDENCE ON CEILING BELOW 5000 FT TONIGHT AND FRIDAY
MORNING.

&&

.PREV DISCUSSION...ISSUED 358 PM EDT THU AUG 21 2014

SHORT TERM...TONIGHT

A FEW LIGHT SHOWERS HAVE STARTED TO BUILD ACROSS SOUTHEAST
MICHIGAN...BUT HAVE FIZZLED OUT AS QUICKLY AS THEY DEVELOPED DUE TO
SIGNIFICANT AMOUNT OF SUBSIDENCE ACROSS THE REGION. NOT EXPECTING
MUCH IN THE WAY OF THUNDERSTORM DEVELOPMENT THE REST OF THE
AFTERNOON...HOWEVER A WARM FRONT ACROSS THE NORTHERN OHIO RIVER
VALLEY WILL BRING AN INCREASED CHANCE OF RAIN SHOWERS TO SOUTHEAST
MICHIGAN THIS EVENING. PRECIPITATION CHANCES WILL BEGIN NEAR THE
OHIO BORDER AND SLOWLY MOVE NORTHWARD AS THIS FRONT LIFTS SLOWLY
ACROSS THE CWA.

RAIN SHOWERS SHOULD CONTINUE OVERNIGHT AS MODELS ARE CONTINUING TO
INDICATE AN MCS /MESOSCALE CONVECTIVE SYSTEM/ TO DEVELOP OVER THE
WESTERN GREAT LAKES. THIS MCS WILL TRACK SOUTHEASTWARD TOWARDS
SOUTHEAST MICHIGAN. CURRENT THINKING IS THAT THE BULK...INCLUDING
THE MOST DAMAGING WIND GUSTS AND SEVERE POTENTIAL...OF THE MCS WILL
TRACK SOUTH OF THE CWA RESULTING IN JUST RAIN SHOWERS ACROSS
SOUTHERN MICHIGAN. HAVE LEFT IN LIKELY POPS ACROSS THE SOUTHERN TWO
TIERS OF COUNTIES TO ACCOUNT FOR ANY DEVIATION ON THE TRACK OF THE
MCS. CURRENT SPC OUTLOOK HAS PULLED BACK ON THE SLIGHT RISK ACROSS
SOUTHERN MICHIGAN...ADDING TO THE CONFIDENCE IN THE CURRENT SOUTHERN
TRACK OF THIS MCS. WITH MOST OF THE SIGNIFICANT THUNDERSTORM
DEVELOPMENT TRACKING SOUTH...THE MAJOR CONCERN FOR SOUTHEAST
MICHIGAN WILL BE THE HEAVY RAIN POTENTIAL. CURRENT MODELS ARE
SHOWING PWAT VALUES IN THE 1.5 TO 2.0 INCH RANGE. THIS WILL RESULT
IN NEARLY AN INCH OR SLIGHTLY MORE OF RAIN TO FALL OVER A SHORT
AMOUNT OF TIME. AT THIS TIME...FLOODING ISSUES ARE NOT A CONCERN.
THIS WILL HAVE TO BE MONITORED CLOSELY AS THE EVENT PROGRESSES AS
LITTLE RAIN FALLING OVER AN ALREADY SATURATED GROUND/URBAN AREAS
COULD QUICKLY RESULT IN FLOODING CONCERNS ACROSS METRO DETROIT AND
SOUTHEAST MICHIGAN.

OTHERWISE...CLOUD COVER OVERNIGHT FROM THE DEVELOPING MCS SHOULD
RESULT IN FAIRLY OVERCAST SKIES KEEPING TEMPERATURES ON THE MILD
SIDE. LOWS SHOULD BE IN THE UPPER 60S IN THE METRO DETROIT AREA AND
SLIGHTLY COOLER IN THE MID 60S ACROSS THE REST OF THE CWA. THIS IS
SLIGHTLY ABOVE AVERAGE FOR THIS TIME OF YEAR WHERE LOWS ARE NORMALLY
IN THE LOW 60S FOR DETROIT AND THE UPPER 50S FOR FLINT AND SAGINAW.

LONG TERM...

NO SUBSTANTIAL CHANGES FROM THE PREVIOUS COUPLE OF FORECAST
PACKAGES. AMPLIFICATION OF THE SUBTROPICAL RIDGE OVER THE SOUTHERN
UNITED STATES IS STILL FORECAST TO RESULT IN SIGNIFICANT WARMING OF
THE COLUMN OVER SE MICHIGAN HEADING INTO THE WEEKEND. H85 TEMPS BOTH
FRI AND SAT WILL BE PUSHING THE UPPER TEENS, WHICH WILL SUPPORT HIGH
TEMPERATURES AT LEAST IN THE LOW 80S. THERE IS SOME UNCERTAINTY
REGARDING THE POTENTIAL MIXING DEPTHS ON FRIDAY OWING TO UNCERTAIN
EVOLUTION OF TONIGHT`S CONVECTION, WHICH CORRESPONDINGLY TEMPERS
EXPECTATIONS FOR FRIDAY`S MAX TEMPS. PERHAPS THE PRIMARY REASON FOR
ABSTAINING FROM PUSHING FOR HIGHER DAYTIME HIGHS, HOWEVER, IS
ACTUALLY MORE OF A CREDIT TO EXPECTED EASTERLY WINDS AT THE SURFACE
AROUND THE SOUTHERN PERIPHERY OF HIGH PRESSURE OVER QUEBEC. THE
PREVIOUS FORECAST HANDLED THIS WELL AND NO CHANGES WERE NECESSARY.
EVEN WITH THE TEMPERED EXPECTATION FOR HIGH TEMPERATURES, THE LACK
OF ANY NOTEWORTHY EXCHANGE OF AIRMASS WILL ENSURE STICKY DEWPOINTS
IN THE MID 60S TO NEAR 70 EACH AFTERNOON. LIKEWISE, THERE REMAINS
SOME CONCERN OVER COOLING POTENTIAL AT NIGHT DUE TO ANTECEDENT MOIST
BOUNDARY LAYER CONDITIONS. AGREE WITH PREVIOUS DISCUSSION THAT THE
PRESENCE OF THETA-E GRADIENT INVOF THE LOWER PENINSULA IMMEDIATELY
DOWNSTREAM OF THE UPPER RIDGE AXIS AND RESIDENT MOIST AIRMASS MAKE
IT ESSENTIALLY IMPOSSIBLE TO RULE OUT SHOWER/T-STORMS DURING ANY ONE
PERIOD. HOWEVER, UNTIL A WELL-DEFINED OPPORTUNITY FOR DEVELOPMENT
PRESENTS ITSELF, THE BEST APPROACH REMAINS TO LEAVE THE FORECAST DRY.

SUNDAY THROUGH THURSDAY: RAIN CHANCES WILL LIKELY HANG AROUND
THROUGH MUCH OF NEXT WEEK AS A SERIES OF SHORTWAVES TRACK OVER
SOUTHEAST MICHIGAN. MODEL AGREEMENT IS STILL QUITE LOW AND HAVE
THEREFORE ONLY PUT IN LOW CHANCE POPS INTO THE FORECAST THROUGH
THURSDAY. TIMING AND COVERAGE OF THE RAIN WILL BE BETTER DEFINED
AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES. TEMPERATURES
WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S AND LOW
TEMPERATURES IN THE MID TO UPPER 60S THROUGH THE PERIOD.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME...ESPECIALLY FOR LAKE SAINT CLAIR AND LAKE ERIE. MODERATE
SOUTHEAST FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT
A MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

AVIATION.....BT
SHORT TERM...RK
LONG TERM....JVC/DE
MARINE.......JVC


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










000
FXUS63 KDTX 211958
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
358 PM EDT THU AUG 21 2014

.SHORT TERM...TONIGHT

A FEW LIGHT SHOWERS HAVE STARTED TO BUILD ACROSS SOUTHEAST
MICHIGAN...BUT HAVE FIZZLED OUT AS QUICKLY AS THEY DEVELOPED DUE TO
SIGNIFICANT AMOUNT OF SUBSIDENCE ACROSS THE REGION. NOT EXPECTING
MUCH IN THE WAY OF THUNDERSTORM DEVELOPMENT THE REST OF THE
AFTERNOON...HOWEVER A WARM FRONT ACROSS THE NORTHERN OHIO RIVER
VALLEY WILL BRING AN INCREASED CHANCE OF RAIN SHOWERS TO SOUTHEAST
MICHIGAN THIS EVENING. PRECIPITATION CHANCES WILL BEGIN NEAR THE
OHIO BORDER AND SLOWLY MOVE NORTHWARD AS THIS FRONT LIFTS SLOWLY
ACROSS THE CWA.

RAIN SHOWERS SHOULD CONTINUE OVERNIGHT AS MODELS ARE CONTINUING TO
INDICATE AN MCS /MESOSCALE CONVECTIVE SYSTEM/ TO DEVELOP OVER THE
WESTERN GREAT LAKES. THIS MCS WILL TRACK SOUTHEASTWARD TOWARDS
SOUTHEAST MICHIGAN. CURRENT THINKING IS THAT THE BULK...INCLUDING
THE MOST DAMAGING WIND GUSTS AND SEVERE POTENTIAL...OF THE MCS WILL
TRACK SOUTH OF THE CWA RESULTING IN JUST RAIN SHOWERS ACROSS
SOUTHERN MICHIGAN. HAVE LEFT IN LIKELY POPS ACROSS THE SOUTHERN TWO
TIERS OF COUNTIES TO ACCOUNT FOR ANY DEVIATION ON THE TRACK OF THE
MCS. CURRENT SPC OUTLOOK HAS PULLED BACK ON THE SLIGHT RISK ACROSS
SOUTHERN MICHIGAN...ADDING TO THE CONFIDENCE IN THE CURRENT SOUTHERN
TRACK OF THIS MCS. WITH MOST OF THE SIGNIFICANT THUNDERSTORM
DEVELOPMENT TRACKING SOUTH...THE MAJOR CONCERN FOR SOUTHEAST
MICHIGAN WILL BE THE HEAVY RAIN POTENTIAL. CURRENT MODELS ARE
SHOWING PWAT VALUES IN THE 1.5 TO 2.0 INCH RANGE. THIS WILL RESULT
IN NEARLY AN INCH OR SLIGHTLY MORE OF RAIN TO FALL OVER A SHORT
AMOUNT OF TIME. AT THIS TIME...FLOODING ISSUES ARE NOT A CONCERN.
THIS WILL HAVE TO BE MONITORED CLOSELY AS THE EVENT PROGRESSES AS
LITTLE RAIN FALLING OVER AN ALREADY SATURATED GROUND/URBAN AREAS
COULD QUICKLY RESULT IN FLOODING CONCERNS ACROSS METRO DETROIT AND
SOUTHEAST MICHIGAN.

OTHERWISE...CLOUD COVER OVERNIGHT FROM THE DEVELOPING MCS SHOULD
RESULT IN FAIRLY OVERCAST SKIES KEEPING TEMPERATURES ON THE MILD
SIDE. LOWS SHOULD BE IN THE UPPER 60S IN THE METRO DETROIT AREA AND
SLIGHTLY COOLER IN THE MID 60S ACROSS THE REST OF THE CWA. THIS IS
SLIGHTLY ABOVE AVERAGE FOR THIS TIME OF YEAR WHERE LOWS ARE NORMALLY
IN THE LOW 60S FOR DETROIT AND THE UPPER 50S FOR FLINT AND SAGINAW.

&&

.LONG TERM...

NO SUBSTANTIAL CHANGES FROM THE PREVIOUS COUPLE OF FORECAST
PACKAGES. AMPLIFICATION OF THE SUBTROPICAL RIDGE OVER THE SOUTHERN
UNITED STATES IS STILL FORECAST TO RESULT IN SIGNIFICANT WARMING OF
THE COLUMN OVER SE MICHIGAN HEADING INTO THE WEEKEND. H85 TEMPS BOTH
FRI AND SAT WILL BE PUSHING THE UPPER TEENS, WHICH WILL SUPPORT HIGH
TEMPERATURES AT LEAST IN THE LOW 80S. THERE IS SOME UNCERTAINTY
REGARDING THE POTENTIAL MIXING DEPTHS ON FRIDAY OWING TO UNCERTAIN
EVOLUTION OF TONIGHT`S CONVECTION, WHICH CORRESPONDINGLY TEMPERS
EXPECTATIONS FOR FRIDAY`S MAX TEMPS. PERHAPS THE PRIMARY REASON FOR
ABSTAINING FROM PUSHING FOR HIGHER DAYTIME HIGHS, HOWEVER, IS
ACTUALLY MORE OF A CREDIT TO EXPECTED EASTERLY WINDS AT THE SURFACE
AROUND THE SOUTHERN PERIPHERY OF HIGH PRESSURE OVER QUEBEC. THE
PREVIOUS FORECAST HANDLED THIS WELL AND NO CHANGES WERE NECESSARY.
EVEN WITH THE TEMPERED EXPECTATION FOR HIGH TEMPERATURES, THE LACK
OF ANY NOTEWORTHY EXCHANGE OF AIRMASS WILL ENSURE STICKY DEWPOINTS
IN THE MID 60S TO NEAR 70 EACH AFTERNOON. LIKEWISE, THERE REMAINS
SOME CONCERN OVER COOLING POTENTIAL AT NIGHT DUE TO ANTECEDENT MOIST
BOUNDARY LAYER CONDITIONS. AGREE WITH PREVIOUS DISCUSSION THAT THE
PRESENCE OF THETA-E GRADIENT INVOF THE LOWER PENINSULA IMMEDIATELY
DOWNSTREAM OF THE UPPER RIDGE AXIS AND RESIDENT MOIST AIRMASS MAKE
IT ESSENTIALLY IMPOSSIBLE TO RULE OUT SHOWER/T-STORMS DURING ANY ONE
PERIOD. HOWEVER, UNTIL A WELL-DEFINED OPPORTUNITY FOR DEVELOPMENT
PRESENTS ITSELF, THE BEST APPROACH REMAINS TO LEAVE THE FORECAST DRY.

SUNDAY THROUGH THURSDAY: RAIN CHANCES WILL LIKELY HANG AROUND
THROUGH MUCH OF NEXT WEEK AS A SERIES OF SHORTWAVES TRACK OVER
SOUTHEAST MICHIGAN. MODEL AGREEMENT IS STILL QUITE LOW AND HAVE
THEREFORE ONLY PUT IN LOW CHANCE POPS INTO THE FORECAST THROUGH
THURSDAY. TIMING AND COVERAGE OF THE RAIN WILL BE BETTER DEFINED
AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES. TEMPERATURES
WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S AND LOW
TEMPERATURES IN THE MID TO UPPER 60S THROUGH THE PERIOD.

&&

.MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME...ESPECIALLY FOR LAKE SAINT CLAIR AND LAKE ERIE. MODERATE
SOUTHEAST FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT
A MINIMUM.

&&

.AVIATION...ISSUED 112 PM EDT THU AUG 21 2014

//DISCUSSION...

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND
INTO THE EARLY EVENING. SOUTHERN TAF SITES WILL MAINLY BE IMPACTED
IN THE LATE AFTERNOON WHILE FNT AND MBS WILL NOT SEE RAIN UNTIL
EARLY EVENING. WINDS WILL REMAIN FAIRLY LIGHT /5 TO 10 KTS/
HOWEVER...WINDS COULD INCREASE QUICKLY IN ANY THUNDERSTORMS THAT
DEVELOP. STEADY RAIN SHOWERS ARE EXPECTED TO CONTINUE THROUGH THE
OVERNIGHT HOURS WITH SOME LIGHT FOG DEVELOPING DROPPING VISIBILITIES
DOWN TO AROUND 2 SM. RAIN SHOWERS WILL GRADUALLY DIMINISH AFTER 12Z
FRIDAY.

//DTW THRESHOLD THREATS...

* MODERATE CONFIDENCE THAT THUNDERSTORMS WILL OCCUR THIS AFTERNOON
AND EARLY EVENING.

* HIGH CONFIDENCE THAT CEILINGS WILL REMAIN BELOW 5000 FT THROUGH
FRIDAY MORNING.

&&

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

&&

$$

SHORT TERM...RK
LONG TERM....JVC/DE
MARINE.......JVC
AVIATION.....RK


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








000
FXUS63 KDTX 211958
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
358 PM EDT THU AUG 21 2014

.SHORT TERM...TONIGHT

A FEW LIGHT SHOWERS HAVE STARTED TO BUILD ACROSS SOUTHEAST
MICHIGAN...BUT HAVE FIZZLED OUT AS QUICKLY AS THEY DEVELOPED DUE TO
SIGNIFICANT AMOUNT OF SUBSIDENCE ACROSS THE REGION. NOT EXPECTING
MUCH IN THE WAY OF THUNDERSTORM DEVELOPMENT THE REST OF THE
AFTERNOON...HOWEVER A WARM FRONT ACROSS THE NORTHERN OHIO RIVER
VALLEY WILL BRING AN INCREASED CHANCE OF RAIN SHOWERS TO SOUTHEAST
MICHIGAN THIS EVENING. PRECIPITATION CHANCES WILL BEGIN NEAR THE
OHIO BORDER AND SLOWLY MOVE NORTHWARD AS THIS FRONT LIFTS SLOWLY
ACROSS THE CWA.

RAIN SHOWERS SHOULD CONTINUE OVERNIGHT AS MODELS ARE CONTINUING TO
INDICATE AN MCS /MESOSCALE CONVECTIVE SYSTEM/ TO DEVELOP OVER THE
WESTERN GREAT LAKES. THIS MCS WILL TRACK SOUTHEASTWARD TOWARDS
SOUTHEAST MICHIGAN. CURRENT THINKING IS THAT THE BULK...INCLUDING
THE MOST DAMAGING WIND GUSTS AND SEVERE POTENTIAL...OF THE MCS WILL
TRACK SOUTH OF THE CWA RESULTING IN JUST RAIN SHOWERS ACROSS
SOUTHERN MICHIGAN. HAVE LEFT IN LIKELY POPS ACROSS THE SOUTHERN TWO
TIERS OF COUNTIES TO ACCOUNT FOR ANY DEVIATION ON THE TRACK OF THE
MCS. CURRENT SPC OUTLOOK HAS PULLED BACK ON THE SLIGHT RISK ACROSS
SOUTHERN MICHIGAN...ADDING TO THE CONFIDENCE IN THE CURRENT SOUTHERN
TRACK OF THIS MCS. WITH MOST OF THE SIGNIFICANT THUNDERSTORM
DEVELOPMENT TRACKING SOUTH...THE MAJOR CONCERN FOR SOUTHEAST
MICHIGAN WILL BE THE HEAVY RAIN POTENTIAL. CURRENT MODELS ARE
SHOWING PWAT VALUES IN THE 1.5 TO 2.0 INCH RANGE. THIS WILL RESULT
IN NEARLY AN INCH OR SLIGHTLY MORE OF RAIN TO FALL OVER A SHORT
AMOUNT OF TIME. AT THIS TIME...FLOODING ISSUES ARE NOT A CONCERN.
THIS WILL HAVE TO BE MONITORED CLOSELY AS THE EVENT PROGRESSES AS
LITTLE RAIN FALLING OVER AN ALREADY SATURATED GROUND/URBAN AREAS
COULD QUICKLY RESULT IN FLOODING CONCERNS ACROSS METRO DETROIT AND
SOUTHEAST MICHIGAN.

OTHERWISE...CLOUD COVER OVERNIGHT FROM THE DEVELOPING MCS SHOULD
RESULT IN FAIRLY OVERCAST SKIES KEEPING TEMPERATURES ON THE MILD
SIDE. LOWS SHOULD BE IN THE UPPER 60S IN THE METRO DETROIT AREA AND
SLIGHTLY COOLER IN THE MID 60S ACROSS THE REST OF THE CWA. THIS IS
SLIGHTLY ABOVE AVERAGE FOR THIS TIME OF YEAR WHERE LOWS ARE NORMALLY
IN THE LOW 60S FOR DETROIT AND THE UPPER 50S FOR FLINT AND SAGINAW.

&&

.LONG TERM...

NO SUBSTANTIAL CHANGES FROM THE PREVIOUS COUPLE OF FORECAST
PACKAGES. AMPLIFICATION OF THE SUBTROPICAL RIDGE OVER THE SOUTHERN
UNITED STATES IS STILL FORECAST TO RESULT IN SIGNIFICANT WARMING OF
THE COLUMN OVER SE MICHIGAN HEADING INTO THE WEEKEND. H85 TEMPS BOTH
FRI AND SAT WILL BE PUSHING THE UPPER TEENS, WHICH WILL SUPPORT HIGH
TEMPERATURES AT LEAST IN THE LOW 80S. THERE IS SOME UNCERTAINTY
REGARDING THE POTENTIAL MIXING DEPTHS ON FRIDAY OWING TO UNCERTAIN
EVOLUTION OF TONIGHT`S CONVECTION, WHICH CORRESPONDINGLY TEMPERS
EXPECTATIONS FOR FRIDAY`S MAX TEMPS. PERHAPS THE PRIMARY REASON FOR
ABSTAINING FROM PUSHING FOR HIGHER DAYTIME HIGHS, HOWEVER, IS
ACTUALLY MORE OF A CREDIT TO EXPECTED EASTERLY WINDS AT THE SURFACE
AROUND THE SOUTHERN PERIPHERY OF HIGH PRESSURE OVER QUEBEC. THE
PREVIOUS FORECAST HANDLED THIS WELL AND NO CHANGES WERE NECESSARY.
EVEN WITH THE TEMPERED EXPECTATION FOR HIGH TEMPERATURES, THE LACK
OF ANY NOTEWORTHY EXCHANGE OF AIRMASS WILL ENSURE STICKY DEWPOINTS
IN THE MID 60S TO NEAR 70 EACH AFTERNOON. LIKEWISE, THERE REMAINS
SOME CONCERN OVER COOLING POTENTIAL AT NIGHT DUE TO ANTECEDENT MOIST
BOUNDARY LAYER CONDITIONS. AGREE WITH PREVIOUS DISCUSSION THAT THE
PRESENCE OF THETA-E GRADIENT INVOF THE LOWER PENINSULA IMMEDIATELY
DOWNSTREAM OF THE UPPER RIDGE AXIS AND RESIDENT MOIST AIRMASS MAKE
IT ESSENTIALLY IMPOSSIBLE TO RULE OUT SHOWER/T-STORMS DURING ANY ONE
PERIOD. HOWEVER, UNTIL A WELL-DEFINED OPPORTUNITY FOR DEVELOPMENT
PRESENTS ITSELF, THE BEST APPROACH REMAINS TO LEAVE THE FORECAST DRY.

SUNDAY THROUGH THURSDAY: RAIN CHANCES WILL LIKELY HANG AROUND
THROUGH MUCH OF NEXT WEEK AS A SERIES OF SHORTWAVES TRACK OVER
SOUTHEAST MICHIGAN. MODEL AGREEMENT IS STILL QUITE LOW AND HAVE
THEREFORE ONLY PUT IN LOW CHANCE POPS INTO THE FORECAST THROUGH
THURSDAY. TIMING AND COVERAGE OF THE RAIN WILL BE BETTER DEFINED
AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES. TEMPERATURES
WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S AND LOW
TEMPERATURES IN THE MID TO UPPER 60S THROUGH THE PERIOD.

&&

.MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME...ESPECIALLY FOR LAKE SAINT CLAIR AND LAKE ERIE. MODERATE
SOUTHEAST FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT
A MINIMUM.

&&

.AVIATION...ISSUED 112 PM EDT THU AUG 21 2014

//DISCUSSION...

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND
INTO THE EARLY EVENING. SOUTHERN TAF SITES WILL MAINLY BE IMPACTED
IN THE LATE AFTERNOON WHILE FNT AND MBS WILL NOT SEE RAIN UNTIL
EARLY EVENING. WINDS WILL REMAIN FAIRLY LIGHT /5 TO 10 KTS/
HOWEVER...WINDS COULD INCREASE QUICKLY IN ANY THUNDERSTORMS THAT
DEVELOP. STEADY RAIN SHOWERS ARE EXPECTED TO CONTINUE THROUGH THE
OVERNIGHT HOURS WITH SOME LIGHT FOG DEVELOPING DROPPING VISIBILITIES
DOWN TO AROUND 2 SM. RAIN SHOWERS WILL GRADUALLY DIMINISH AFTER 12Z
FRIDAY.

//DTW THRESHOLD THREATS...

* MODERATE CONFIDENCE THAT THUNDERSTORMS WILL OCCUR THIS AFTERNOON
AND EARLY EVENING.

* HIGH CONFIDENCE THAT CEILINGS WILL REMAIN BELOW 5000 FT THROUGH
FRIDAY MORNING.

&&

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

&&

$$

SHORT TERM...RK
LONG TERM....JVC/DE
MARINE.......JVC
AVIATION.....RK


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







000
FXUS63 KDTX 211712
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
112 PM EDT THU AUG 21 2014


.AVIATION...

//DISCUSSION...

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND
INTO THE EARLY EVENING. SOUTHERN TAF SITES WILL MAINLY BE IMPACTED
IN THE LATE AFTERNOON WHILE FNT AND MBS WILL NOT SEE RAIN UNTIL
EARLY EVENING. WINDS WILL REMAIN FAIRLY LIGHT /5 TO 10 KTS/
HOWEVER...WINDS COULD INCREASE QUICKLY IN ANY THUNDERSTORMS THAT
DEVELOP. STEADY RAIN SHOWERS ARE EXPECTED TO CONTINUE THROUGH THE
OVERNIGHT HOURS WITH SOME LIGHT FOG DEVELOPING DROPPING VISIBILITIES
DOWN TO AROUND 2 SM. RAIN SHOWERS WILL GRADUALLY DIMINISH AFTER 12Z
FRIDAY.


//DTW THRESHOLD THREATS...

* MODERATE CONFIDENCE THAT THUNDERSTORMS WILL OCCUR THIS AFTERNOON
AND EARLY EVENING.

* HIGH CONFIDENCE THAT CEILINGS WILL REMAIN BELOW 5000 FT THROUGH
FRIDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 330 AM EDT THU AUG 21 2014

SHORT TERM...TODAY AND TONIGHT

SOME MORNING FOG IS AGAIN POSSIBLE WITH JUICY DEW POINTS STILL IN
PLACE ACROSS SOUTHEAST MICHIGAN WITH LIGHT WINDS AND AREAS OF CLEAR
SKIES. HOWEVER FOG FORMATION WILL BE MITIGATED BY CIRRUS BLOWOFF
FROM UPSTREAM CONVECTION WHICH IS LIMITING RADIATIONAL COOLING AND
SOME SHOWERS ACROSS THE EXTREME CWA. THEREFORE DO NOT EXPECT FOG TO
BE AS BAD AS YESTERDAY MORNING WITH THE BEST CHANCE ALONG AND NORTH
OF THE I-69 CORRIDOR WHICH WILL BE FARTHER AWAY FROM THE CIRRUS.

A WARM FRONT RESIDING OVER THE NORTHERN OHIO VALLEY WILL SLOWLY LIFT
NORTH TO THE OHIO BORDER TODAY...CREEPING NORTH INTO SOUTHERN LOWER
MICHIGAN DURING THE OVERNIGHT HOURS. PRECIPITATION CHANCES WILL
INCREASE FROM SOUTH TO NORTH TODAY AND TONIGHT AS THIS FRONT LIFTS
NORTH...BRINGING WARM UNSTABLE AIR INTO SOUTHEAST MICHIGAN. ACTIVITY
TODAY AND EARLY THIS EVENING SHOULD MAINLY BE DIURNALLY DRIVEN AND
ASSOCIATED WITH THE WARM FRONT LIFTING NORTH. DESPITE MUCAPES OF
1000 TO 1500 J/KG...SEVERE WEATHER IS NOT ANTICIPATED DURING THIS
PERIOD AS THE LOW LEVEL WIND FIELD IS VERY WEAK DURING THIS PERIOD
WITH AN ALMOST STRAIGHT HODOGRAPH. HEAVY RAIN IS POSSIBLE GIVEN THE
LONG SKINNY HODOGRAPHS AND PWAT VALUES OF 1 TO 1.5 INCHES.

LATER THIS EVENING INTO TONIGHT IS A DIFFERENT STORY AS THE MODELS
DEVELOP A MESOSCALE CONVECTIVE SYSTEM OVER THE WESTERN GREAT LAKES
TODAY...BARRELING EAST SOUTHEAST ALONG THE WARM FRONT WHICH WILL BE
LAID OUT OVER THE SOUTHERN GREAT LAKES TONIGHT. THIS SYSTEM COULD
BRING SOME DAMAGING WIND GUSTS AS IT TRACKS ALONG THE WARM
FRONT...WITH THE GREATEST POTENTIAL FOR SEVERE WEATHER ALONG THE
OHIO BORDER WITH THE WARM FRONT...WHICH IS IN LINE WITH THE LATEST
SPC DAY 1 OUTLOOK. IN ADDITION TO DAMAGING WINDS...HEAVY RAIN AND
FLOODING IS A CONCERN OVER THIS SAME AREA AS PWAT VALUES SOAR TO
AROUND 2 INCHES. WILL HOLD OFF ON ANY FLASH FLOOD WATCH HEADLINES
UNTIL THE EVENT DRAWS CLOSER AND THE TRACK OF THE MCS CAN BE BETTER
ASCERTAINED.

LONG TERM...

THE CONSENSUS OF THE 21.00Z DETERMINISTIC SOLUTIONS OFFERS SOME
RESOLUTION TO WHAT HAD BEEN A NOISY AND CLOUDED PROGRESSION INTO THE
AMPLIFYING LONGWAVE RIDGE. IN SHORT...THE EASTWARD MIGRATION OF THE
UPPER LEVEL RIDGE AXIS APPEARS TO BE SLOWER THAN EARLIER ADVERTISED.
THIS WILL SIGNIFICANTLY APPLY THE BRAKES ON THE MAGNITUDE OF THE
WARMUP FOR THIS UPCOMING WEEKEND. IN FACT...THE LOWER TROPOSPHERE
NOW APPEARS IT WILL BE DOMINATED BY COOL EASTERLY DRAINAGE FLOW OFF
OF A STABLE ANTICYCLONE OVER PORTIONS OF QUEBEC. QUITE A LITTLE
DIFFERENCE HERE WITH THE FORECAST.

FRIDAY...A MIX OF MODEL DATA INCLUDING HIRES ECMWF AND IN-HOUSE
HIRES CONVECTION ALLOWING ENSEMBLE SUGGESTS MCS ACTIVITY WILL BE
SOUTH OF THE CWA BY 12Z. FOR NOW...DID NOT GET TOO AGGRESSIVE
LOWERING OR REMOVING POPS...BUT DID TAKE THE THUMB OUT OF THE
CHANCES. LARGE SCALE PURE DEFORMATION STRUCTURE SUGGESTS THE
THERMAL/EQUIVALENT POTENTIAL TEMPERATURE GRADIENT IN PLACE OVER THE
REGION WILL BE VERY STABLE...AND WILL NOT MOVE MUCH. WAVE
RESPONSIBLE AND LOW PRESSURE SYSTEM PARTIALLY DRIVEN BY THE MCS WILL
SETTLE TO THE SOUTHEASTWARD WHILE SHOWING SOME MARGINAL
STRENGTHENING. SO...ON THE NORTHERN EDGE OF THIS WAVE EXPECTING A
FAIRLY UNIFORM RESPONSE OF SURFACE WINDS TO AN EASTERLY DIRECTION.
HIGHS WILL ONLY RISE TO AROUND 80 DEGREES.

MODELS ARE SHOWING A VERY CLEAN SIGNAL IN EXPANDING AND
STRENGTHENING THE SURFACE HIGH OVER SE MICH FRIDAY NIGHT. THIS IS A
CLASSIC NOCTURNAL RESPONSE AND WENT DECIDEDLY COOLER WITH MINS.

SATURDAY...MODELS KEEP A VERY CLEAN SIGNAL FOR CONTINUED SURFACE
RIDGING OVER SOUTHEASTERN MICHIGAN ON SATURDAY. NOT A REAL LOT TO
SAY HERE...WITH A VERY DRY AND STABLE ATMOSPHERIC PROFILE IN THE
LOWEST 5000 FT AGL. REMOVED POPS ACROSS THE BOARD. ALSO PREFER THE
COOLER END OF THE SPECTRUM WHICH IS STILL LOW 80S FOR HIGHS...UPPER
70S LAKE HURON SHORELINE. BROKEN RECORD HERE...WENT COOL WITH LOWS
SATURDAY NIGHT.

SUNDAY...BY SUNDAY THE RIDGE IS EXPECTED TO BE FOLDING OVER INTO
SOUTHEASTERN MICHIGAN. STRONG AVA WITH SOLID WARM AIR ADVECTION
SUPPORTS A PATTERN OF STRONG SUBSIDENCE IN THE COLUMN. MODEL
SOUNDINGS FROM THIS VANTAGE POINT ARE SHOWING A DOMINANCE OF STABLE
LAYER THROUGH THE LOWEST 6 FT FOR ANOTHER DAY WITH A CAPPING
INVERSION. THE OFFERED GUIDANCE GAVE A LOW CHANCE POP AND THAT
APPEARS FINE GIVEN WARM AIR ADVECTION AND INTRODUCTION OF STEEPER
MIDLEVEL LAPSE RATES. THE FORECASTED HIGHS FOR SUNDAY ARE A COUPLE
OF DEGREES WARMER...LOW TO MID 80S.

OVERALL...WAS PRETTY AGGRESSIVE IN MAKING ADJUSTMENTS TO THIS
FORECAST PACKAGE. WHILE THERE WILL REMAIN NONZERO CHANCES FOR
SHOWERS AND THUNDERSTORMS DURING THE FRIDAY NIGHT THROUGH SATURDAY
NIGHT TIMEFRAME...FELT IT WAS NOT A GOOD CALL TO BLAST CHANCE POPS
DURING THAT TIMEFRAME.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME. THE BETTER POTENTIAL FOR THE STRONG TO SEVERE THUNDERSTORMS
WILL BE OVER SOUTHERN LOWER MICHIGAN AWAY FROM LAKE HURON. MODERATE
SOUTHWESTERLY FLOW WILL EVENTUALLY DEVELOP BY SUNDAY BUT WIND GUSTS
WILL REMAIN AT A MINIMUM.

&&

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

&&

$$

AVIATION.....RK
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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







000
FXUS63 KDTX 211712
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
112 PM EDT THU AUG 21 2014


.AVIATION...

//DISCUSSION...

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND
INTO THE EARLY EVENING. SOUTHERN TAF SITES WILL MAINLY BE IMPACTED
IN THE LATE AFTERNOON WHILE FNT AND MBS WILL NOT SEE RAIN UNTIL
EARLY EVENING. WINDS WILL REMAIN FAIRLY LIGHT /5 TO 10 KTS/
HOWEVER...WINDS COULD INCREASE QUICKLY IN ANY THUNDERSTORMS THAT
DEVELOP. STEADY RAIN SHOWERS ARE EXPECTED TO CONTINUE THROUGH THE
OVERNIGHT HOURS WITH SOME LIGHT FOG DEVELOPING DROPPING VISIBILITIES
DOWN TO AROUND 2 SM. RAIN SHOWERS WILL GRADUALLY DIMINISH AFTER 12Z
FRIDAY.


//DTW THRESHOLD THREATS...

* MODERATE CONFIDENCE THAT THUNDERSTORMS WILL OCCUR THIS AFTERNOON
AND EARLY EVENING.

* HIGH CONFIDENCE THAT CEILINGS WILL REMAIN BELOW 5000 FT THROUGH
FRIDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 330 AM EDT THU AUG 21 2014

SHORT TERM...TODAY AND TONIGHT

SOME MORNING FOG IS AGAIN POSSIBLE WITH JUICY DEW POINTS STILL IN
PLACE ACROSS SOUTHEAST MICHIGAN WITH LIGHT WINDS AND AREAS OF CLEAR
SKIES. HOWEVER FOG FORMATION WILL BE MITIGATED BY CIRRUS BLOWOFF
FROM UPSTREAM CONVECTION WHICH IS LIMITING RADIATIONAL COOLING AND
SOME SHOWERS ACROSS THE EXTREME CWA. THEREFORE DO NOT EXPECT FOG TO
BE AS BAD AS YESTERDAY MORNING WITH THE BEST CHANCE ALONG AND NORTH
OF THE I-69 CORRIDOR WHICH WILL BE FARTHER AWAY FROM THE CIRRUS.

A WARM FRONT RESIDING OVER THE NORTHERN OHIO VALLEY WILL SLOWLY LIFT
NORTH TO THE OHIO BORDER TODAY...CREEPING NORTH INTO SOUTHERN LOWER
MICHIGAN DURING THE OVERNIGHT HOURS. PRECIPITATION CHANCES WILL
INCREASE FROM SOUTH TO NORTH TODAY AND TONIGHT AS THIS FRONT LIFTS
NORTH...BRINGING WARM UNSTABLE AIR INTO SOUTHEAST MICHIGAN. ACTIVITY
TODAY AND EARLY THIS EVENING SHOULD MAINLY BE DIURNALLY DRIVEN AND
ASSOCIATED WITH THE WARM FRONT LIFTING NORTH. DESPITE MUCAPES OF
1000 TO 1500 J/KG...SEVERE WEATHER IS NOT ANTICIPATED DURING THIS
PERIOD AS THE LOW LEVEL WIND FIELD IS VERY WEAK DURING THIS PERIOD
WITH AN ALMOST STRAIGHT HODOGRAPH. HEAVY RAIN IS POSSIBLE GIVEN THE
LONG SKINNY HODOGRAPHS AND PWAT VALUES OF 1 TO 1.5 INCHES.

LATER THIS EVENING INTO TONIGHT IS A DIFFERENT STORY AS THE MODELS
DEVELOP A MESOSCALE CONVECTIVE SYSTEM OVER THE WESTERN GREAT LAKES
TODAY...BARRELING EAST SOUTHEAST ALONG THE WARM FRONT WHICH WILL BE
LAID OUT OVER THE SOUTHERN GREAT LAKES TONIGHT. THIS SYSTEM COULD
BRING SOME DAMAGING WIND GUSTS AS IT TRACKS ALONG THE WARM
FRONT...WITH THE GREATEST POTENTIAL FOR SEVERE WEATHER ALONG THE
OHIO BORDER WITH THE WARM FRONT...WHICH IS IN LINE WITH THE LATEST
SPC DAY 1 OUTLOOK. IN ADDITION TO DAMAGING WINDS...HEAVY RAIN AND
FLOODING IS A CONCERN OVER THIS SAME AREA AS PWAT VALUES SOAR TO
AROUND 2 INCHES. WILL HOLD OFF ON ANY FLASH FLOOD WATCH HEADLINES
UNTIL THE EVENT DRAWS CLOSER AND THE TRACK OF THE MCS CAN BE BETTER
ASCERTAINED.

LONG TERM...

THE CONSENSUS OF THE 21.00Z DETERMINISTIC SOLUTIONS OFFERS SOME
RESOLUTION TO WHAT HAD BEEN A NOISY AND CLOUDED PROGRESSION INTO THE
AMPLIFYING LONGWAVE RIDGE. IN SHORT...THE EASTWARD MIGRATION OF THE
UPPER LEVEL RIDGE AXIS APPEARS TO BE SLOWER THAN EARLIER ADVERTISED.
THIS WILL SIGNIFICANTLY APPLY THE BRAKES ON THE MAGNITUDE OF THE
WARMUP FOR THIS UPCOMING WEEKEND. IN FACT...THE LOWER TROPOSPHERE
NOW APPEARS IT WILL BE DOMINATED BY COOL EASTERLY DRAINAGE FLOW OFF
OF A STABLE ANTICYCLONE OVER PORTIONS OF QUEBEC. QUITE A LITTLE
DIFFERENCE HERE WITH THE FORECAST.

FRIDAY...A MIX OF MODEL DATA INCLUDING HIRES ECMWF AND IN-HOUSE
HIRES CONVECTION ALLOWING ENSEMBLE SUGGESTS MCS ACTIVITY WILL BE
SOUTH OF THE CWA BY 12Z. FOR NOW...DID NOT GET TOO AGGRESSIVE
LOWERING OR REMOVING POPS...BUT DID TAKE THE THUMB OUT OF THE
CHANCES. LARGE SCALE PURE DEFORMATION STRUCTURE SUGGESTS THE
THERMAL/EQUIVALENT POTENTIAL TEMPERATURE GRADIENT IN PLACE OVER THE
REGION WILL BE VERY STABLE...AND WILL NOT MOVE MUCH. WAVE
RESPONSIBLE AND LOW PRESSURE SYSTEM PARTIALLY DRIVEN BY THE MCS WILL
SETTLE TO THE SOUTHEASTWARD WHILE SHOWING SOME MARGINAL
STRENGTHENING. SO...ON THE NORTHERN EDGE OF THIS WAVE EXPECTING A
FAIRLY UNIFORM RESPONSE OF SURFACE WINDS TO AN EASTERLY DIRECTION.
HIGHS WILL ONLY RISE TO AROUND 80 DEGREES.

MODELS ARE SHOWING A VERY CLEAN SIGNAL IN EXPANDING AND
STRENGTHENING THE SURFACE HIGH OVER SE MICH FRIDAY NIGHT. THIS IS A
CLASSIC NOCTURNAL RESPONSE AND WENT DECIDEDLY COOLER WITH MINS.

SATURDAY...MODELS KEEP A VERY CLEAN SIGNAL FOR CONTINUED SURFACE
RIDGING OVER SOUTHEASTERN MICHIGAN ON SATURDAY. NOT A REAL LOT TO
SAY HERE...WITH A VERY DRY AND STABLE ATMOSPHERIC PROFILE IN THE
LOWEST 5000 FT AGL. REMOVED POPS ACROSS THE BOARD. ALSO PREFER THE
COOLER END OF THE SPECTRUM WHICH IS STILL LOW 80S FOR HIGHS...UPPER
70S LAKE HURON SHORELINE. BROKEN RECORD HERE...WENT COOL WITH LOWS
SATURDAY NIGHT.

SUNDAY...BY SUNDAY THE RIDGE IS EXPECTED TO BE FOLDING OVER INTO
SOUTHEASTERN MICHIGAN. STRONG AVA WITH SOLID WARM AIR ADVECTION
SUPPORTS A PATTERN OF STRONG SUBSIDENCE IN THE COLUMN. MODEL
SOUNDINGS FROM THIS VANTAGE POINT ARE SHOWING A DOMINANCE OF STABLE
LAYER THROUGH THE LOWEST 6 FT FOR ANOTHER DAY WITH A CAPPING
INVERSION. THE OFFERED GUIDANCE GAVE A LOW CHANCE POP AND THAT
APPEARS FINE GIVEN WARM AIR ADVECTION AND INTRODUCTION OF STEEPER
MIDLEVEL LAPSE RATES. THE FORECASTED HIGHS FOR SUNDAY ARE A COUPLE
OF DEGREES WARMER...LOW TO MID 80S.

OVERALL...WAS PRETTY AGGRESSIVE IN MAKING ADJUSTMENTS TO THIS
FORECAST PACKAGE. WHILE THERE WILL REMAIN NONZERO CHANCES FOR
SHOWERS AND THUNDERSTORMS DURING THE FRIDAY NIGHT THROUGH SATURDAY
NIGHT TIMEFRAME...FELT IT WAS NOT A GOOD CALL TO BLAST CHANCE POPS
DURING THAT TIMEFRAME.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME. THE BETTER POTENTIAL FOR THE STRONG TO SEVERE THUNDERSTORMS
WILL BE OVER SOUTHERN LOWER MICHIGAN AWAY FROM LAKE HURON. MODERATE
SOUTHWESTERLY FLOW WILL EVENTUALLY DEVELOP BY SUNDAY BUT WIND GUSTS
WILL REMAIN AT A MINIMUM.

&&

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

&&

$$

AVIATION.....RK
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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








000
FXUS63 KDTX 211114
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
714 AM EDT THU AUG 21 2014


.AVIATION...

//DISCUSSION...

DESPITE BEING SURROUNDED BY MVFR AND IFR CONDITIONS...MANY OF THE
TAF SITES THEMSELVES HAVE NOT DROPPED CONDITIONS WITH THE FOG.  IN
FACT AS OF THIS WRITING ALL BUT ONE SITE IS AT VFR. EXPECT SITES TO
POSSIBLY DROP TO MVFR THIS MORNING BEFORE THE SUN BURNS OFF THE FOG
BY 14Z. SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND
INTO THE EARLY EVENING AS A WARM FRONT LIFTS NORTH. A MORE
SUBSTANTIAL ROUND OF ACTIVITY IS EXPECTED OVERNIGHT AS AN MCS TRACKS
ALONG THE WARM FRONT ACROSS THE OHIO BORDER.


//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET WITH SHOWERS BY LATE
  AFTERNOON THROUGH THIS EVENING.

&&

.PREV DISCUSSION...ISSUED 330 AM EDT THU AUG 21 2014

SHORT TERM...TODAY AND TONIGHT

SOME MORNING FOG IS AGAIN POSSIBLE WITH JUICY DEW POINTS STILL IN
PLACE ACROSS SOUTHEAST MICHIGAN WITH LIGHT WINDS AND AREAS OF CLEAR
SKIES. HOWEVER FOG FORMATION WILL BE MITIGATED BY CIRRUS BLOWOFF
FROM UPSTREAM CONVECTION WHICH IS LIMITING RADIATIONAL COOLING AND
SOME SHOWERS ACROSS THE EXTREME CWA. THEREFORE DO NOT EXPECT FOG TO
BE AS BAD AS YESTERDAY MORNING WITH THE BEST CHANCE ALONG AND NORTH
OF THE I-69 CORRIDOR WHICH WILL BE FARTHER AWAY FROM THE CIRRUS.

A WARM FRONT RESIDING OVER THE NORTHERN OHIO VALLEY WILL SLOWLY LIFT
NORTH TO THE OHIO BORDER TODAY...CREEPING NORTH INTO SOUTHERN LOWER
MICHIGAN DURING THE OVERNIGHT HOURS. PRECIPITATION CHANCES WILL
INCREASE FROM SOUTH TO NORTH TODAY AND TONIGHT AS THIS FRONT LIFTS
NORTH...BRINGING WARM UNSTABLE AIR INTO SOUTHEAST MICHIGAN. ACTIVITY
TODAY AND EARLY THIS EVENING SHOULD MAINLY BE DIURNALLY DRIVEN AND
ASSOCIATED WITH THE WARM FRONT LIFTING NORTH. DESPITE MUCAPES OF
1000 TO 1500 J/KG...SEVERE WEATHER IS NOT ANTICIPATED DURING THIS
PERIOD AS THE LOW LEVEL WIND FIELD IS VERY WEAK DURING THIS PERIOD
WITH AN ALMOST STRAIGHT HODOGRAPH. HEAVY RAIN IS POSSIBLE GIVEN THE
LONG SKINNY HODOGRAPHS AND PWAT VALUES OF 1 TO 1.5 INCHES.

LATER THIS EVENING INTO TONIGHT IS A DIFFERENT STORY AS THE MODELS
DEVELOP A MESOSCALE CONVECTIVE SYSTEM OVER THE WESTERN GREAT LAKES
TODAY...BARRELING EAST SOUTHEAST ALONG THE WARM FRONT WHICH WILL BE
LAID OUT OVER THE SOUTHERN GREAT LAKES TONIGHT. THIS SYSTEM COULD
BRING SOME DAMAGING WIND GUSTS AS IT TRACKS ALONG THE WARM
FRONT...WITH THE GREATEST POTENTIAL FOR SEVERE WEATHER ALONG THE
OHIO BORDER WITH THE WARM FRONT...WHICH IS IN LINE WITH THE LATEST
SPC DAY 1 OUTLOOK. IN ADDITION TO DAMAGING WINDS...HEAVY RAIN AND
FLOODING IS A CONCERN OVER THIS SAME AREA AS PWAT VALUES SOAR TO
AROUND 2 INCHES. WILL HOLD OFF ON ANY FLASH FLOOD WATCH HEADLINES
UNTIL THE EVENT DRAWS CLOSER AND THE TRACK OF THE MCS CAN BE BETTER
ASCERTAINED.

LONG TERM...

THE CONSENSUS OF THE 21.00Z DETERMINISTIC SOLUTIONS OFFERS SOME
RESOLUTION TO WHAT HAD BEEN A NOISY AND CLOUDED PROGRESSION INTO THE
AMPLIFYING LONGWAVE RIDGE. IN SHORT...THE EASTWARD MIGRATION OF THE
UPPER LEVEL RIDGE AXIS APPEARS TO BE SLOWER THAN EARLIER ADVERTISED.
THIS WILL SIGNIFICANTLY APPLY THE BRAKES ON THE MAGNITUDE OF THE
WARMUP FOR THIS UPCOMING WEEKEND. IN FACT...THE LOWER TROPOSPHERE
NOW APPEARS IT WILL BE DOMINATED BY COOL EASTERLY DRAINAGE FLOW OFF
OF A STABLE ANTICYCLONE OVER PORTIONS OF QUEBEC. QUITE A LITTLE
DIFFERENCE HERE WITH THE FORECAST.

FRIDAY...A MIX OF MODEL DATA INCLUDING HIRES ECMWF AND IN-HOUSE
HIRES CONVECTION ALLOWING ENSEMBLE SUGGESTS MCS ACTIVITY WILL BE
SOUTH OF THE CWA BY 12Z. FOR NOW...DID NOT GET TOO AGGRESSIVE
LOWERING OR REMOVING POPS...BUT DID TAKE THE THUMB OUT OF THE
CHANCES. LARGE SCALE PURE DEFORMATION STRUCTURE SUGGESTS THE
THERMAL/EQUIVALENT POTENTIAL TEMPERATURE GRADIENT IN PLACE OVER THE
REGION WILL BE VERY STABLE...AND WILL NOT MOVE MUCH. WAVE
RESPONSIBLE AND LOW PRESSURE SYSTEM PARTIALLY DRIVEN BY THE MCS WILL
SETTLE TO THE SOUTHEASTWARD WHILE SHOWING SOME MARGINAL
STRENGTHENING. SO...ON THE NORTHERN EDGE OF THIS WAVE EXPECTING A
FAIRLY UNIFORM RESPONSE OF SURFACE WINDS TO AN EASTERLY DIRECTION.
HIGHS WILL ONLY RISE TO AROUND 80 DEGREES.

MODELS ARE SHOWING A VERY CLEAN SIGNAL IN EXPANDING AND
STRENGTHENING THE SURFACE HIGH OVER SEMICH FRIDAY NIGHT. THIS IS A
CLASSIC NOCTURNAL RESPONSE AND WENT DECIDEDLY COOLER WITH MINS.

SATURDAY...MODELS KEEP A VERY CLEAN SIGNAL FOR CONTINUED SURFACE
RIDGING OVER SOUTHEASTERN MICHIGAN ON SATURDAY. NOT A REAL LOT TO
SAY HERE...WITH A VERY DRY AND STABLE ATMOSPHERIC PROFILE IN THE
LOWEST 5000 FT AGL. REMOVED POPS ACROSS THE BOARD. ALSO PREFER THE
COOLER END OF THE SPECTRUM WHICH IS STILL LOW 80S FOR HIGHS...UPPER
70S LAKE HURON SHORELINE. BROKEN RECORD HERE...WENT COOL WITH LOWS
SATURDAY NIGHT.

SUNDAY...BY SUNDAY THE RIDGE IS EXPECTED TO BE FOLDING OVER INTO
SOUTHEASTERN MICHIGAN. STRONG AVA WITH SOLID WARM AIR ADVECTION
SUPPORTS A PATTERN OF STRONG SUBSIDENCE IN THE COLUMN. MODEL
SOUNDINGS FROM THIS VANTAGE POINT ARE SHOWING A DOMINANCE OF STABLE
LAYER THROUGH THE LOWEST 6 FT FOR ANOTHER DAY WITH A CAPPING
INVERSION. THE OFFERED GUIDANCE GAVE A LOW CHANCE POP AND THAT
APPEARS FINE GIVEN WARM AIR ADVECTION AND INTRODUCTION OF STEEPER
MIDLEVEL LAPSE RATES. THE FORECASTED HIGHS FOR SUNDAY ARE A COUPLE
OF DEGREES WARMER...LOW TO MID 80S.

OVERALL...WAS PRETTY AGGRESSIVE IN MAKING ADJUSTMENTS TO THIS
FORECAST PACKAGE. WHILE THERE WILL REMAIN NONZERO CHANCES FOR
SHOWERS AND THUNDERSTORMS DURING THE FRIDAY NIGHT THROUGH SATURDAY
NIGHT TIMEFRAME...FELT IT WAS NOT A GOOD CALL TO BLAST CHANCE POPS
DURING THAT TIMEFRAME.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME. THE BETTER POTENTIAL FOR THE STRONG TO SEVERE THUNDERSTORMS
WILL BE OVER SOUTHERN LOWER MICHIGAN AWAY FROM LAKE HURON. MODERATE
SOUTHWESTERLY FLOW WILL EVENTUALLY DEVELOP BY SUNDAY BUT WIND GUSTS
WILL REMAIN AT A MINIMUM.

&&

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

&&

$$

AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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







000
FXUS63 KDTX 211114
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
714 AM EDT THU AUG 21 2014


.AVIATION...

//DISCUSSION...

DESPITE BEING SURROUNDED BY MVFR AND IFR CONDITIONS...MANY OF THE
TAF SITES THEMSELVES HAVE NOT DROPPED CONDITIONS WITH THE FOG.  IN
FACT AS OF THIS WRITING ALL BUT ONE SITE IS AT VFR. EXPECT SITES TO
POSSIBLY DROP TO MVFR THIS MORNING BEFORE THE SUN BURNS OFF THE FOG
BY 14Z. SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND
INTO THE EARLY EVENING AS A WARM FRONT LIFTS NORTH. A MORE
SUBSTANTIAL ROUND OF ACTIVITY IS EXPECTED OVERNIGHT AS AN MCS TRACKS
ALONG THE WARM FRONT ACROSS THE OHIO BORDER.


//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET WITH SHOWERS BY LATE
  AFTERNOON THROUGH THIS EVENING.

&&

.PREV DISCUSSION...ISSUED 330 AM EDT THU AUG 21 2014

SHORT TERM...TODAY AND TONIGHT

SOME MORNING FOG IS AGAIN POSSIBLE WITH JUICY DEW POINTS STILL IN
PLACE ACROSS SOUTHEAST MICHIGAN WITH LIGHT WINDS AND AREAS OF CLEAR
SKIES. HOWEVER FOG FORMATION WILL BE MITIGATED BY CIRRUS BLOWOFF
FROM UPSTREAM CONVECTION WHICH IS LIMITING RADIATIONAL COOLING AND
SOME SHOWERS ACROSS THE EXTREME CWA. THEREFORE DO NOT EXPECT FOG TO
BE AS BAD AS YESTERDAY MORNING WITH THE BEST CHANCE ALONG AND NORTH
OF THE I-69 CORRIDOR WHICH WILL BE FARTHER AWAY FROM THE CIRRUS.

A WARM FRONT RESIDING OVER THE NORTHERN OHIO VALLEY WILL SLOWLY LIFT
NORTH TO THE OHIO BORDER TODAY...CREEPING NORTH INTO SOUTHERN LOWER
MICHIGAN DURING THE OVERNIGHT HOURS. PRECIPITATION CHANCES WILL
INCREASE FROM SOUTH TO NORTH TODAY AND TONIGHT AS THIS FRONT LIFTS
NORTH...BRINGING WARM UNSTABLE AIR INTO SOUTHEAST MICHIGAN. ACTIVITY
TODAY AND EARLY THIS EVENING SHOULD MAINLY BE DIURNALLY DRIVEN AND
ASSOCIATED WITH THE WARM FRONT LIFTING NORTH. DESPITE MUCAPES OF
1000 TO 1500 J/KG...SEVERE WEATHER IS NOT ANTICIPATED DURING THIS
PERIOD AS THE LOW LEVEL WIND FIELD IS VERY WEAK DURING THIS PERIOD
WITH AN ALMOST STRAIGHT HODOGRAPH. HEAVY RAIN IS POSSIBLE GIVEN THE
LONG SKINNY HODOGRAPHS AND PWAT VALUES OF 1 TO 1.5 INCHES.

LATER THIS EVENING INTO TONIGHT IS A DIFFERENT STORY AS THE MODELS
DEVELOP A MESOSCALE CONVECTIVE SYSTEM OVER THE WESTERN GREAT LAKES
TODAY...BARRELING EAST SOUTHEAST ALONG THE WARM FRONT WHICH WILL BE
LAID OUT OVER THE SOUTHERN GREAT LAKES TONIGHT. THIS SYSTEM COULD
BRING SOME DAMAGING WIND GUSTS AS IT TRACKS ALONG THE WARM
FRONT...WITH THE GREATEST POTENTIAL FOR SEVERE WEATHER ALONG THE
OHIO BORDER WITH THE WARM FRONT...WHICH IS IN LINE WITH THE LATEST
SPC DAY 1 OUTLOOK. IN ADDITION TO DAMAGING WINDS...HEAVY RAIN AND
FLOODING IS A CONCERN OVER THIS SAME AREA AS PWAT VALUES SOAR TO
AROUND 2 INCHES. WILL HOLD OFF ON ANY FLASH FLOOD WATCH HEADLINES
UNTIL THE EVENT DRAWS CLOSER AND THE TRACK OF THE MCS CAN BE BETTER
ASCERTAINED.

LONG TERM...

THE CONSENSUS OF THE 21.00Z DETERMINISTIC SOLUTIONS OFFERS SOME
RESOLUTION TO WHAT HAD BEEN A NOISY AND CLOUDED PROGRESSION INTO THE
AMPLIFYING LONGWAVE RIDGE. IN SHORT...THE EASTWARD MIGRATION OF THE
UPPER LEVEL RIDGE AXIS APPEARS TO BE SLOWER THAN EARLIER ADVERTISED.
THIS WILL SIGNIFICANTLY APPLY THE BRAKES ON THE MAGNITUDE OF THE
WARMUP FOR THIS UPCOMING WEEKEND. IN FACT...THE LOWER TROPOSPHERE
NOW APPEARS IT WILL BE DOMINATED BY COOL EASTERLY DRAINAGE FLOW OFF
OF A STABLE ANTICYCLONE OVER PORTIONS OF QUEBEC. QUITE A LITTLE
DIFFERENCE HERE WITH THE FORECAST.

FRIDAY...A MIX OF MODEL DATA INCLUDING HIRES ECMWF AND IN-HOUSE
HIRES CONVECTION ALLOWING ENSEMBLE SUGGESTS MCS ACTIVITY WILL BE
SOUTH OF THE CWA BY 12Z. FOR NOW...DID NOT GET TOO AGGRESSIVE
LOWERING OR REMOVING POPS...BUT DID TAKE THE THUMB OUT OF THE
CHANCES. LARGE SCALE PURE DEFORMATION STRUCTURE SUGGESTS THE
THERMAL/EQUIVALENT POTENTIAL TEMPERATURE GRADIENT IN PLACE OVER THE
REGION WILL BE VERY STABLE...AND WILL NOT MOVE MUCH. WAVE
RESPONSIBLE AND LOW PRESSURE SYSTEM PARTIALLY DRIVEN BY THE MCS WILL
SETTLE TO THE SOUTHEASTWARD WHILE SHOWING SOME MARGINAL
STRENGTHENING. SO...ON THE NORTHERN EDGE OF THIS WAVE EXPECTING A
FAIRLY UNIFORM RESPONSE OF SURFACE WINDS TO AN EASTERLY DIRECTION.
HIGHS WILL ONLY RISE TO AROUND 80 DEGREES.

MODELS ARE SHOWING A VERY CLEAN SIGNAL IN EXPANDING AND
STRENGTHENING THE SURFACE HIGH OVER SEMICH FRIDAY NIGHT. THIS IS A
CLASSIC NOCTURNAL RESPONSE AND WENT DECIDEDLY COOLER WITH MINS.

SATURDAY...MODELS KEEP A VERY CLEAN SIGNAL FOR CONTINUED SURFACE
RIDGING OVER SOUTHEASTERN MICHIGAN ON SATURDAY. NOT A REAL LOT TO
SAY HERE...WITH A VERY DRY AND STABLE ATMOSPHERIC PROFILE IN THE
LOWEST 5000 FT AGL. REMOVED POPS ACROSS THE BOARD. ALSO PREFER THE
COOLER END OF THE SPECTRUM WHICH IS STILL LOW 80S FOR HIGHS...UPPER
70S LAKE HURON SHORELINE. BROKEN RECORD HERE...WENT COOL WITH LOWS
SATURDAY NIGHT.

SUNDAY...BY SUNDAY THE RIDGE IS EXPECTED TO BE FOLDING OVER INTO
SOUTHEASTERN MICHIGAN. STRONG AVA WITH SOLID WARM AIR ADVECTION
SUPPORTS A PATTERN OF STRONG SUBSIDENCE IN THE COLUMN. MODEL
SOUNDINGS FROM THIS VANTAGE POINT ARE SHOWING A DOMINANCE OF STABLE
LAYER THROUGH THE LOWEST 6 FT FOR ANOTHER DAY WITH A CAPPING
INVERSION. THE OFFERED GUIDANCE GAVE A LOW CHANCE POP AND THAT
APPEARS FINE GIVEN WARM AIR ADVECTION AND INTRODUCTION OF STEEPER
MIDLEVEL LAPSE RATES. THE FORECASTED HIGHS FOR SUNDAY ARE A COUPLE
OF DEGREES WARMER...LOW TO MID 80S.

OVERALL...WAS PRETTY AGGRESSIVE IN MAKING ADJUSTMENTS TO THIS
FORECAST PACKAGE. WHILE THERE WILL REMAIN NONZERO CHANCES FOR
SHOWERS AND THUNDERSTORMS DURING THE FRIDAY NIGHT THROUGH SATURDAY
NIGHT TIMEFRAME...FELT IT WAS NOT A GOOD CALL TO BLAST CHANCE POPS
DURING THAT TIMEFRAME.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME. THE BETTER POTENTIAL FOR THE STRONG TO SEVERE THUNDERSTORMS
WILL BE OVER SOUTHERN LOWER MICHIGAN AWAY FROM LAKE HURON. MODERATE
SOUTHWESTERLY FLOW WILL EVENTUALLY DEVELOP BY SUNDAY BUT WIND GUSTS
WILL REMAIN AT A MINIMUM.

&&

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

&&

$$

AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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








000
FXUS63 KDTX 210730
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
330 AM EDT THU AUG 21 2014

.SHORT TERM...TODAY AND TONIGHT

SOME MORNING FOG IS AGAIN POSSIBLE WITH JUICY DEW POINTS STILL IN
PLACE ACROSS SOUTHEAST MICHIGAN WITH LIGHT WINDS AND AREAS OF CLEAR
SKIES. HOWEVER FOG FORMATION WILL BE MITIGATED BY CIRRUS BLOWOFF
FROM UPSTREAM CONVECTION WHICH IS LIMITING RADIATIONAL COOLING AND
SOME SHOWERS ACROSS THE EXTREME CWA. THEREFORE DO NOT EXPECT FOG TO
BE AS BAD AS YESTERDAY MORNING WITH THE BEST CHANCE ALONG AND NORTH
OF THE I-69 CORRIDOR WHICH WILL BE FARTHER AWAY FROM THE CIRRUS.

A WARM FRONT RESIDING OVER THE NORTHERN OHIO VALLEY WILL SLOWLY LIFT
NORTH TO THE OHIO BORDER TODAY...CREEPING NORTH INTO SOUTHERN LOWER
MICHIGAN DURING THE OVERNIGHT HOURS. PRECIPITATION CHANCES WILL
INCREASE FROM SOUTH TO NORTH TODAY AND TONIGHT AS THIS FRONT LIFTS
NORTH...BRINGING WARM UNSTABLE AIR INTO SOUTHEAST MICHIGAN. ACTIVITY
TODAY AND EARLY THIS EVENING SHOULD MAINLY BE DIURNALLY DRIVEN AND
ASSOCIATED WITH THE WARM FRONT LIFTING NORTH. DESPITE MUCAPES OF
1000 TO 1500 J/KG...SEVERE WEATHER IS NOT ANTICIPATED DURING THIS
PERIOD AS THE LOW LEVEL WIND FIELD IS VERY WEAK DURING THIS PERIOD
WITH AN ALMOST STRAIGHT HODOGRAPH. HEAVY RAIN IS POSSIBLE GIVEN THE
LONG SKINNY HODOGRAPHS AND PWAT VALUES OF 1 TO 1.5 INCHES.

LATER THIS EVENING INTO TONIGHT IS A DIFFERENT STORY AS THE MODELS
DEVELOP A MESOSCALE CONVECTIVE SYSTEM OVER THE WESTERN GREAT LAKES
TODAY...BARRELING EAST SOUTHEAST ALONG THE WARM FRONT WHICH WILL BE
LAID OUT OVER THE SOUTHERN GREAT LAKES TONIGHT. THIS SYSTEM COULD
BRING SOME DAMAGING WIND GUSTS AS IT TRACKS ALONG THE WARM
FRONT...WITH THE GREATEST POTENTIAL FOR SEVERE WEATHER ALONG THE
OHIO BORDER WITH THE WARM FRONT...WHICH IS IN LINE WITH THE LATEST
SPC DAY 1 OUTLOOK. IN ADDITION TO DAMAGING WINDS...HEAVY RAIN AND
FLOODING IS A CONCERN OVER THIS SAME AREA AS PWAT VALUES SOAR TO
AROUND 2 INCHES. WILL HOLD OFF ON ANY FLASH FLOOD WATCH HEADLINES
UNTIL THE EVENT DRAWS CLOSER AND THE TRACK OF THE MCS CAN BE BETTER
ASCERTAINED.

&&

.LONG TERM...

THE CONSENSUS OF THE 21.00Z DETERMINISTIC SOLUTIONS OFFERS SOME
RESOLUTION TO WHAT HAD BEEN A NOISY AND CLOUDED PROGRESSION INTO THE
AMPLIFYING LONGWAVE RIDGE. IN SHORT...THE EASTWARD MIGRATION OF THE
UPPER LEVEL RIDGE AXIS APPEARS TO BE SLOWER THAN EARLIER ADVERTISED.
THIS WILL SIGNIFICANTLY APPLY THE BRAKES ON THE MAGNITUDE OF THE
WARMUP FOR THIS UPCOMING WEEKEND. IN FACT...THE LOWER TROPOSPHERE
NOW APPEARS IT WILL BE DOMINATED BY COOL EASTERLY DRAINAGE FLOW OFF
OF A STABLE ANTICYCLONE OVER PORTIONS OF QUEBEC. QUITE A LITTLE
DIFFERENCE HERE WITH THE FORECAST.

FRIDAY...A MIX OF MODEL DATA INCLUDING HIRES ECMWF AND IN-HOUSE
HIRES CONVECTION ALLOWING ENSEMBLE SUGGESTS MCS ACTIVITY WILL BE
SOUTH OF THE CWA BY 12Z. FOR NOW...DID NOT GET TOO AGGRESSIVE
LOWERING OR REMOVING POPS...BUT DID TAKE THE THUMB OUT OF THE
CHANCES. LARGE SCALE PURE DEFORMATION STRUCTURE SUGGESTS THE
THERMAL/EQUIVALENT POTENTIAL TEMPERATURE GRADIENT IN PLACE OVER THE
REGION WILL BE VERY STABLE...AND WILL NOT MOVE MUCH. WAVE
RESPONSIBLE AND LOW PRESSURE SYSTEM PARTIALLY DRIVEN BY THE MCS WILL
SETTLE TO THE SOUTHEASTWARD WHILE SHOWING SOME MARGINAL
STRENGTHENING. SO...ON THE NORTHERN EDGE OF THIS WAVE EXPECTING A
FAIRLY UNIFORM RESPONSE OF SURFACE WINDS TO AN EASTERLY DIRECTION.
HIGHS WILL ONLY RISE TO AROUND 80 DEGREES.

MODELS ARE SHOWING A VERY CLEAN SIGNAL IN EXPANDING AND
STRENGTHENING THE SURFACE HIGH OVER SEMICH FRIDAY NIGHT. THIS IS A
CLASSIC NOCTURNAL RESPONSE AND WENT DECIDEDLY COOLER WITH MINS.

SATURDAY...MODELS KEEP A VERY CLEAN SIGNAL FOR CONTINUED SURFACE
RIDGING OVER SOUTHEASTERN MICHIGAN ON SATURDAY. NOT A REAL LOT TO
SAY HERE...WITH A VERY DRY AND STABLE ATMOSPHERIC PROFILE IN THE
LOWEST 5000 FT AGL. REMOVED POPS ACROSS THE BOARD. ALSO PREFER THE
COOLER END OF THE SPECTRUM WHICH IS STILL LOW 80S FOR HIGHS...UPPER
70S LAKE HURON SHORELINE. BROKEN RECORD HERE...WENT COOL WITH LOWS
SATURDAY NIGHT.

SUNDAY...BY SUNDAY THE RIDGE IS EXPECTED TO BE FOLDING OVER INTO
SOUTHEASTERN MICHIGAN. STRONG AVA WITH SOLID WARM AIR ADVECTION
SUPPORTS A PATTERN OF STRONG SUBSIDENCE IN THE COLUMN. MODEL
SOUNDINGS FROM THIS VANTAGE POINT ARE SHOWING A DOMINANCE OF STABLE
LAYER THROUGH THE LOWEST 6 FT FOR ANOTHER DAY WITH A CAPPING
INVERSION. THE OFFERED GUIDANCE GAVE A LOW CHANCE POP AND THAT
APPEARS FINE GIVEN WARM AIR ADVECTION AND INTRODUCTION OF STEEPER
MIDLEVEL LAPSE RATES. THE FORECASTED HIGHS FOR SUNDAY ARE A COUPLE
OF DEGREES WARMER...LOW TO MID 80S.

OVERALL...WAS PRETTY AGGRESSIVE IN MAKING ADJUSTMENTS TO THIS
FORECAST PACKAGE. WHILE THERE WILL REMAIN NONZERO CHANCES FOR
SHOWERS AND THUNDERSTORMS DURING THE FRIDAY NIGHT THROUGH SATURDAY
NIGHT TIMEFRAME...FELT IT WAS NOT A GOOD CALL TO BLAST CHANCE POPS
DURING THAT TIMEFRAME.

&&

.MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME. THE BETTER POTENTIAL FOR THE STRONG TO SEVERE THUNDERSTORMS
WILL BE OVER SOUTHERN LOWER MICHIGAN AWAY FROM LAKE HURON. MODERATE
SOUTHWESTERLY FLOW WILL EVENTUALLY DEVELOP BY SUNDAY BUT WIND GUSTS
WILL REMAIN AT A MINIMUM.

&&

.AVIATION...ISSUED 1205 AM EDT THU AUG 21 2014

//DISCUSSION...

THE CLOUD PATTERN LEADING UP TO MIDNIGHT CONTINUES TO FAVOR MBS AND
FNT AS THE MOST LIKELY LOCATIONS FOR IFR FOG AND PERHAPS EVEN A LOW
END MVFR OR IFR CEILING BEFORE SUNRISE. EXPECT IFR CONDITIONS TO
RESULT IN SIMILAR RESTRICTION TO WEDNESDAY MORNING FOLLOWED BY A
TYPICAL TREND OF MORNING IMPROVEMENT. THE FOG SITUATION IN THE DTW
AREA WILL BE MITIGATED BY AN INCREASE IN MID CLOUDS ASSOCIATED WITH
THE WARM FRONT DEVELOPING UPSTREAM. A ROUND OF SHOWERS IS THEN
EXPECTED DURING THE LATE AFTERNOON INTO THURSDAY EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET WITH SHOWERS BY LATE
AFTERNOON THROUGH THURSDAY EVENING.

&&

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

&&

$$

SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB
AVIATION.....BT


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







000
FXUS63 KDTX 210730
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
330 AM EDT THU AUG 21 2014

.SHORT TERM...TODAY AND TONIGHT

SOME MORNING FOG IS AGAIN POSSIBLE WITH JUICY DEW POINTS STILL IN
PLACE ACROSS SOUTHEAST MICHIGAN WITH LIGHT WINDS AND AREAS OF CLEAR
SKIES. HOWEVER FOG FORMATION WILL BE MITIGATED BY CIRRUS BLOWOFF
FROM UPSTREAM CONVECTION WHICH IS LIMITING RADIATIONAL COOLING AND
SOME SHOWERS ACROSS THE EXTREME CWA. THEREFORE DO NOT EXPECT FOG TO
BE AS BAD AS YESTERDAY MORNING WITH THE BEST CHANCE ALONG AND NORTH
OF THE I-69 CORRIDOR WHICH WILL BE FARTHER AWAY FROM THE CIRRUS.

A WARM FRONT RESIDING OVER THE NORTHERN OHIO VALLEY WILL SLOWLY LIFT
NORTH TO THE OHIO BORDER TODAY...CREEPING NORTH INTO SOUTHERN LOWER
MICHIGAN DURING THE OVERNIGHT HOURS. PRECIPITATION CHANCES WILL
INCREASE FROM SOUTH TO NORTH TODAY AND TONIGHT AS THIS FRONT LIFTS
NORTH...BRINGING WARM UNSTABLE AIR INTO SOUTHEAST MICHIGAN. ACTIVITY
TODAY AND EARLY THIS EVENING SHOULD MAINLY BE DIURNALLY DRIVEN AND
ASSOCIATED WITH THE WARM FRONT LIFTING NORTH. DESPITE MUCAPES OF
1000 TO 1500 J/KG...SEVERE WEATHER IS NOT ANTICIPATED DURING THIS
PERIOD AS THE LOW LEVEL WIND FIELD IS VERY WEAK DURING THIS PERIOD
WITH AN ALMOST STRAIGHT HODOGRAPH. HEAVY RAIN IS POSSIBLE GIVEN THE
LONG SKINNY HODOGRAPHS AND PWAT VALUES OF 1 TO 1.5 INCHES.

LATER THIS EVENING INTO TONIGHT IS A DIFFERENT STORY AS THE MODELS
DEVELOP A MESOSCALE CONVECTIVE SYSTEM OVER THE WESTERN GREAT LAKES
TODAY...BARRELING EAST SOUTHEAST ALONG THE WARM FRONT WHICH WILL BE
LAID OUT OVER THE SOUTHERN GREAT LAKES TONIGHT. THIS SYSTEM COULD
BRING SOME DAMAGING WIND GUSTS AS IT TRACKS ALONG THE WARM
FRONT...WITH THE GREATEST POTENTIAL FOR SEVERE WEATHER ALONG THE
OHIO BORDER WITH THE WARM FRONT...WHICH IS IN LINE WITH THE LATEST
SPC DAY 1 OUTLOOK. IN ADDITION TO DAMAGING WINDS...HEAVY RAIN AND
FLOODING IS A CONCERN OVER THIS SAME AREA AS PWAT VALUES SOAR TO
AROUND 2 INCHES. WILL HOLD OFF ON ANY FLASH FLOOD WATCH HEADLINES
UNTIL THE EVENT DRAWS CLOSER AND THE TRACK OF THE MCS CAN BE BETTER
ASCERTAINED.

&&

.LONG TERM...

THE CONSENSUS OF THE 21.00Z DETERMINISTIC SOLUTIONS OFFERS SOME
RESOLUTION TO WHAT HAD BEEN A NOISY AND CLOUDED PROGRESSION INTO THE
AMPLIFYING LONGWAVE RIDGE. IN SHORT...THE EASTWARD MIGRATION OF THE
UPPER LEVEL RIDGE AXIS APPEARS TO BE SLOWER THAN EARLIER ADVERTISED.
THIS WILL SIGNIFICANTLY APPLY THE BRAKES ON THE MAGNITUDE OF THE
WARMUP FOR THIS UPCOMING WEEKEND. IN FACT...THE LOWER TROPOSPHERE
NOW APPEARS IT WILL BE DOMINATED BY COOL EASTERLY DRAINAGE FLOW OFF
OF A STABLE ANTICYCLONE OVER PORTIONS OF QUEBEC. QUITE A LITTLE
DIFFERENCE HERE WITH THE FORECAST.

FRIDAY...A MIX OF MODEL DATA INCLUDING HIRES ECMWF AND IN-HOUSE
HIRES CONVECTION ALLOWING ENSEMBLE SUGGESTS MCS ACTIVITY WILL BE
SOUTH OF THE CWA BY 12Z. FOR NOW...DID NOT GET TOO AGGRESSIVE
LOWERING OR REMOVING POPS...BUT DID TAKE THE THUMB OUT OF THE
CHANCES. LARGE SCALE PURE DEFORMATION STRUCTURE SUGGESTS THE
THERMAL/EQUIVALENT POTENTIAL TEMPERATURE GRADIENT IN PLACE OVER THE
REGION WILL BE VERY STABLE...AND WILL NOT MOVE MUCH. WAVE
RESPONSIBLE AND LOW PRESSURE SYSTEM PARTIALLY DRIVEN BY THE MCS WILL
SETTLE TO THE SOUTHEASTWARD WHILE SHOWING SOME MARGINAL
STRENGTHENING. SO...ON THE NORTHERN EDGE OF THIS WAVE EXPECTING A
FAIRLY UNIFORM RESPONSE OF SURFACE WINDS TO AN EASTERLY DIRECTION.
HIGHS WILL ONLY RISE TO AROUND 80 DEGREES.

MODELS ARE SHOWING A VERY CLEAN SIGNAL IN EXPANDING AND
STRENGTHENING THE SURFACE HIGH OVER SEMICH FRIDAY NIGHT. THIS IS A
CLASSIC NOCTURNAL RESPONSE AND WENT DECIDEDLY COOLER WITH MINS.

SATURDAY...MODELS KEEP A VERY CLEAN SIGNAL FOR CONTINUED SURFACE
RIDGING OVER SOUTHEASTERN MICHIGAN ON SATURDAY. NOT A REAL LOT TO
SAY HERE...WITH A VERY DRY AND STABLE ATMOSPHERIC PROFILE IN THE
LOWEST 5000 FT AGL. REMOVED POPS ACROSS THE BOARD. ALSO PREFER THE
COOLER END OF THE SPECTRUM WHICH IS STILL LOW 80S FOR HIGHS...UPPER
70S LAKE HURON SHORELINE. BROKEN RECORD HERE...WENT COOL WITH LOWS
SATURDAY NIGHT.

SUNDAY...BY SUNDAY THE RIDGE IS EXPECTED TO BE FOLDING OVER INTO
SOUTHEASTERN MICHIGAN. STRONG AVA WITH SOLID WARM AIR ADVECTION
SUPPORTS A PATTERN OF STRONG SUBSIDENCE IN THE COLUMN. MODEL
SOUNDINGS FROM THIS VANTAGE POINT ARE SHOWING A DOMINANCE OF STABLE
LAYER THROUGH THE LOWEST 6 FT FOR ANOTHER DAY WITH A CAPPING
INVERSION. THE OFFERED GUIDANCE GAVE A LOW CHANCE POP AND THAT
APPEARS FINE GIVEN WARM AIR ADVECTION AND INTRODUCTION OF STEEPER
MIDLEVEL LAPSE RATES. THE FORECASTED HIGHS FOR SUNDAY ARE A COUPLE
OF DEGREES WARMER...LOW TO MID 80S.

OVERALL...WAS PRETTY AGGRESSIVE IN MAKING ADJUSTMENTS TO THIS
FORECAST PACKAGE. WHILE THERE WILL REMAIN NONZERO CHANCES FOR
SHOWERS AND THUNDERSTORMS DURING THE FRIDAY NIGHT THROUGH SATURDAY
NIGHT TIMEFRAME...FELT IT WAS NOT A GOOD CALL TO BLAST CHANCE POPS
DURING THAT TIMEFRAME.

&&

.MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THERE IS A CHANCE FOR
THUNDERSTORMS FOR ALL MARINE AREAS LATE TONIGHT INTO EARLY
FRIDAY...AND SEVERE WEATHER IS NOT OUT OF THE QUESTION DURING THIS
TIME. THE BETTER POTENTIAL FOR THE STRONG TO SEVERE THUNDERSTORMS
WILL BE OVER SOUTHERN LOWER MICHIGAN AWAY FROM LAKE HURON. MODERATE
SOUTHWESTERLY FLOW WILL EVENTUALLY DEVELOP BY SUNDAY BUT WIND GUSTS
WILL REMAIN AT A MINIMUM.

&&

.AVIATION...ISSUED 1205 AM EDT THU AUG 21 2014

//DISCUSSION...

THE CLOUD PATTERN LEADING UP TO MIDNIGHT CONTINUES TO FAVOR MBS AND
FNT AS THE MOST LIKELY LOCATIONS FOR IFR FOG AND PERHAPS EVEN A LOW
END MVFR OR IFR CEILING BEFORE SUNRISE. EXPECT IFR CONDITIONS TO
RESULT IN SIMILAR RESTRICTION TO WEDNESDAY MORNING FOLLOWED BY A
TYPICAL TREND OF MORNING IMPROVEMENT. THE FOG SITUATION IN THE DTW
AREA WILL BE MITIGATED BY AN INCREASE IN MID CLOUDS ASSOCIATED WITH
THE WARM FRONT DEVELOPING UPSTREAM. A ROUND OF SHOWERS IS THEN
EXPECTED DURING THE LATE AFTERNOON INTO THURSDAY EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET WITH SHOWERS BY LATE
AFTERNOON THROUGH THURSDAY EVENING.

&&

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

&&

$$

SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB
AVIATION.....BT


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








000
FXUS63 KDTX 210405
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1205 AM EDT THU AUG 21 2014

.AVIATION...

//DISCUSSION...

THE CLOUD PATTERN LEADING UP TO MIDNIGHT CONTINUES TO FAVOR MBS AND
FNT AS THE MOST LIKELY LOCATIONS FOR IFR FOG AND PERHAPS EVEN A LOW
END MVFR OR IFR CEILING BEFORE SUNRISE. EXPECT IFR CONDITIONS TO
RESULT IN SIMILAR RESTRICTION TO WEDNESDAY MORNING FOLLOWED BY A
TYPICAL TREND OF MORNING IMPROVEMENT. THE FOG SITUATION IN THE DTW
AREA WILL BE MITIGATED BY AN INCREASE IN MID CLOUDS ASSOCIATED WITH
THE WARM FRONT DEVELOPING UPSTREAM. A ROUND OF SHOWERS IS THEN
EXPECTED DURING THE LATE AFTERNOON INTO THURSDAY EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET WITH SHOWERS BY LATE
AFTERNOON THROUGH THURSDAY EVENING.

&&

.PREV DISCUSSION...ISSUED 943 PM EDT WED AUG 20 2014

UPDATE...

A COUPLE OF THINGS TO MONITOR DURING THE NIGHT THROUGH THURSDAY
MORNING INCLUDE FOG POTENTIAL AND THE CHANCE OF SHOWERS
REDEVELOPING LATER IN THE NIGHT. AS FOR FOG...WE ARE STARTING OUT
TONIGHT WITH A SIMILAR BOUNDARY LAYER MOISTURE PROFILE BUT A FEW
DEGREES WARMER THAN LAST NIGHT. THERE IS ALSO LESS CLOUD COVER BUT
NOT AS MUCH WET GROUND. THINKING THE GOING FORECAST HAS THE
SITUATION COVERED WELL WITH AREAS OF FOG ALONG AND NORTH OF I-69.
THIS IS WHERE SHOWER COVERAGE WAS GREATEST DURING THE DAY AND WHERE
THE SKY WILL REMAIN CLEAR THE LONGEST AS THE WIND GOES LIGHT AND
VARIABLE TONIGHT. SOUTH OF THERE...TEMP/DEWPOINT SPREAD IS
GREATER AND CLOUDS WILL INCREASE AGAIN EARLIER IN THE FORM OF
CIRRUS AND ALTOCU. THERE COULD EVEN BE A HIGH-BASED SHOWER AS FAR
NORTH AS I-96 CONSIDERING THE STRENGTH OF THE MID LEVEL THETA-E
ADVECTION BY SUNRISE.

PREV DISCUSSION...ISSUED 323 PM EDT WED AUG 20 2014

SHORT TERM...TONIGHT

STACKED LOW PRESSURE CONTINUES TO CHURN OVER NORTHERN MICHIGAN THIS
EVENING. THE UPPER LOW WILL PIVOT SOME THIS EVENING TO CREATE A
NEGATIVE TILT WITHIN THE BROAD 500MB TROUGH PATTERN TONIGHT. AS THE
FEATURE TILTS...AN AREA OF SURFACE CONVERGENCE WILL HELP SPARK
CONTINUED SHOWERS WITH ISOLATED THUNDERSTORMS. WHILE THERE IS A
FORECASTED MAXIMUM OF 25KT H85 WINDS OVER SRN MI THIS EVENING...THE
OVERALL FLOW IS VERY WEAK. THIS WILL LEAD TO SLOW MOVING SINGLE
CELLS. BOTH MOISTURE CONTENT AND INSTABILITY ARE MODEST TODAY /1.5
INCH PWAT AND 1500 J/KG CAPE/ BUT ARE AMPLE TO PRODUCE SOME
CONVECTION WITH LITTLE POTENTIAL FOR DAMAGING WINDS OR HAIL. 0-6 KM
BULK SHEAR OF 25 KT IS UNIDIRECTIONAL...LEADING TO LITTLE RISK FOR
ROTATION TODAY.

THE DIURNALLY DRIVEN CONVECTION WILL COME TO AN END AFTER 01Z THIS
EVENING. JUST A FEW ISOLATED SHOWERS WILL BE POSSIBLE THEREAFTER
FROM THE SAGINAW VALLEY TO EASTERN THUMB REGION...CLOSER TO THE
CENTER OF THE SURFACE LOW. MINS TONIGHT RANGE FROM THE UPPER 50 TO
LOW 60S. THERE IS POTENTIAL FOR AM FOG AGAIN TOMORROW...WHICH MAY BE
MITIGATED BY CIRRUS BLOWOFF FROM UPSTREAM WARM FRONTAL SYSTEM. AREAS
NORTH OF I-69 HOLD THE BETTER CHANCE FOR FOG DEVELOPMENT WITH LIGHT
WINDS AND INCREASED MOISTURE CONTENT.

LONG TERM...

LONGWAVE FEEDBACK ASSOCIATED WITH STRONG JET ENERGY DIGGING INTO THE
PAC NW AND INTERMOUNTAIN WEST WILL FORCE THE SUBTROPICAL RIDGE
ANCHORED OVER THE SOUTHERN UNITED STATES TO UNDERGO NOTEWORTHY
AMPLIFICATION HEADING INTO THE WEEKEND. DURING THIS TIME, SOUTHEAST
MICHIGAN WILL RESIDE ON THE EDGE OF THE INSTABILITY GRADIENT WITH NO
APPRECIABLE UPPER FORCING TO SPEAK OF. AS A RESULT, THE FORECAST
FEATURES SEVERAL PERIODS CONSISTING MAINLY OF CHANCE POPS TO ACCOUNT
FOR THE RATHER NEBULOUS PERIOD OF CONVECTIVE POTENTIAL.

DURING THE NEXT 48 HOURS, THE HIGHEST PROBABILITY SCENARIO WILL BE
FOR SOUTHEAST MICHIGAN TO FEAST UPON THE LEFTOVERS OF UPSTREAM
REMNANTS. HIGH RES SOLUTIONS SUGGEST THAT THIS WILL BE THE CASE ON
THURSDAY AS HIGH PLAINS REMNANTS PROPAGATE INTO THE OHIO VALLEY,
EXPERIENCING A DIURNAL FLARE-UP DURING THE DAY WHICH IS MOST LIKELY
TO OCCUR TO OUR SOUTH...OR AT LEAST SOUTH OF THE METRO AREA...GIVEN
THE PROGGED LOCATION OF HIGHER INSTABILITY. HOWEVER...DIURNAL
HEATING INVOF NORTHWARD ADVANCING WARM FRONT WILL PRESENT THE
OPPORTUNITY FOR ISOLATED TO PERHAPS SCATTERED THUNDERSTORM DEVELOP
DURING THE DAY. ADEQUATE SHEAR AROUND 35 KNOTS WILL BE SUFFICIENT TO
SUPPORT ORGANIZED UPDRAFTS DEPENDING ON CLOUD COVER/INSTABILITY, SO
A MARGINAL RISK FOR SEVERE WEATHER DOES EXIST.

A SIMILAR SITUATION WILL BE PRESENT THURSDAY NIGHT INTO FRIDAY
MORNING, EXCEPT WITH THE FAVORABLE THERMODYNAMIC ENVIRONMENT
CREEPING CLOSER. THE GENESIS REGION FOR ANY THURSDAY NIGHT ACTIVITY
WILL LIKELY BE INVOF THE APEX OF THE RIDGE/EDGE OF THE CAP SOMEWHERE
IN THE UPPER MS RIVER VALLEY PER PATTERN RECOGNITION/HIGH-RES MODEL
SIGNALS. MESOSCALE DETAILS THAT WILL NOT BECOME CLEAR UNTIL THURSDAY
OR THURSDAY NIGHT ENTER THE NEAR TERM WILL BE CRITICAL. THE
POTENTIAL FOR COLD POOL DEVELOPMENT AND MAINTENANCE WILL NEED TO BE
MONITORED AS IT WILL DETERMINE THE POTENTIAL FOR UPSCALE GROWTH AS
THIS ACTIVITY DIVES INTO THE LOWER PENINSULA, WHERE THE
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE - BUT NOT EXCEPTIONAL -
LATE THURSDAY NIGHT.

HIGH TEMPS WILL CREEP UPWARD THROUGH MUCH OF THE LONG TERM PERIOD AS
THE AFOREMENTIONED RIDGE AMPLIFIES AND H85 TEMPERATURES INCREASE
INTO THE UPPER TEENS BY FRIDAY...AND THEN FURTHER HEADING INTO THE
WEEKEND. NO ARGUMENTS WITH THE GUIDANCE WHICH SUGGESTS DAYTIME HIGHS
HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE UPPER 60S.

RAIN CHANCES WILL LIKELY STICK AROUND THROUGH NEXT WEEK AS A SERIES
OF SHORTWAVES TRACK OVER SOUTHEAST MICHIGAN. MODEL AGREEMENT IS
STILL QUITE LOW AND HAVE THEREFORE ONLY PUT IN LOW CHANCE POPS INTO
THE FORECAST THROUGH WEDNESDAY. TIMING AND COVERAGE OF THE RAIN WILL
BE REFINED AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES.
TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID TO UPPER 60S THROUGH WEDNESDAY.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THUNDERSTORM CHANCES WILL
PERSIST MAINLY FOR CENTRAL LAKE HURON AND POINTS SOUTH THROUGH THIS
EVENING. THERE IS THEN A CHANCE FOR THUNDERSTORMS FOR ALL MARINE
AREAS LATE THURSDAY NIGHT INTO EARLY FRIDAY...AND SEVERE WEATHER IS
NOT OUT OF THE QUESTION DURING THIS TIME. MODERATE SOUTHWESTERLY
FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT A
MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

AVIATION.....BT
UPDATE.......BT
SHORT TERM...MM
LONG TERM....JVC/RK
MARINE.......JVC


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








000
FXUS63 KDTX 210405
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1205 AM EDT THU AUG 21 2014

.AVIATION...

//DISCUSSION...

THE CLOUD PATTERN LEADING UP TO MIDNIGHT CONTINUES TO FAVOR MBS AND
FNT AS THE MOST LIKELY LOCATIONS FOR IFR FOG AND PERHAPS EVEN A LOW
END MVFR OR IFR CEILING BEFORE SUNRISE. EXPECT IFR CONDITIONS TO
RESULT IN SIMILAR RESTRICTION TO WEDNESDAY MORNING FOLLOWED BY A
TYPICAL TREND OF MORNING IMPROVEMENT. THE FOG SITUATION IN THE DTW
AREA WILL BE MITIGATED BY AN INCREASE IN MID CLOUDS ASSOCIATED WITH
THE WARM FRONT DEVELOPING UPSTREAM. A ROUND OF SHOWERS IS THEN
EXPECTED DURING THE LATE AFTERNOON INTO THURSDAY EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET WITH SHOWERS BY LATE
AFTERNOON THROUGH THURSDAY EVENING.

&&

.PREV DISCUSSION...ISSUED 943 PM EDT WED AUG 20 2014

UPDATE...

A COUPLE OF THINGS TO MONITOR DURING THE NIGHT THROUGH THURSDAY
MORNING INCLUDE FOG POTENTIAL AND THE CHANCE OF SHOWERS
REDEVELOPING LATER IN THE NIGHT. AS FOR FOG...WE ARE STARTING OUT
TONIGHT WITH A SIMILAR BOUNDARY LAYER MOISTURE PROFILE BUT A FEW
DEGREES WARMER THAN LAST NIGHT. THERE IS ALSO LESS CLOUD COVER BUT
NOT AS MUCH WET GROUND. THINKING THE GOING FORECAST HAS THE
SITUATION COVERED WELL WITH AREAS OF FOG ALONG AND NORTH OF I-69.
THIS IS WHERE SHOWER COVERAGE WAS GREATEST DURING THE DAY AND WHERE
THE SKY WILL REMAIN CLEAR THE LONGEST AS THE WIND GOES LIGHT AND
VARIABLE TONIGHT. SOUTH OF THERE...TEMP/DEWPOINT SPREAD IS
GREATER AND CLOUDS WILL INCREASE AGAIN EARLIER IN THE FORM OF
CIRRUS AND ALTOCU. THERE COULD EVEN BE A HIGH-BASED SHOWER AS FAR
NORTH AS I-96 CONSIDERING THE STRENGTH OF THE MID LEVEL THETA-E
ADVECTION BY SUNRISE.

PREV DISCUSSION...ISSUED 323 PM EDT WED AUG 20 2014

SHORT TERM...TONIGHT

STACKED LOW PRESSURE CONTINUES TO CHURN OVER NORTHERN MICHIGAN THIS
EVENING. THE UPPER LOW WILL PIVOT SOME THIS EVENING TO CREATE A
NEGATIVE TILT WITHIN THE BROAD 500MB TROUGH PATTERN TONIGHT. AS THE
FEATURE TILTS...AN AREA OF SURFACE CONVERGENCE WILL HELP SPARK
CONTINUED SHOWERS WITH ISOLATED THUNDERSTORMS. WHILE THERE IS A
FORECASTED MAXIMUM OF 25KT H85 WINDS OVER SRN MI THIS EVENING...THE
OVERALL FLOW IS VERY WEAK. THIS WILL LEAD TO SLOW MOVING SINGLE
CELLS. BOTH MOISTURE CONTENT AND INSTABILITY ARE MODEST TODAY /1.5
INCH PWAT AND 1500 J/KG CAPE/ BUT ARE AMPLE TO PRODUCE SOME
CONVECTION WITH LITTLE POTENTIAL FOR DAMAGING WINDS OR HAIL. 0-6 KM
BULK SHEAR OF 25 KT IS UNIDIRECTIONAL...LEADING TO LITTLE RISK FOR
ROTATION TODAY.

THE DIURNALLY DRIVEN CONVECTION WILL COME TO AN END AFTER 01Z THIS
EVENING. JUST A FEW ISOLATED SHOWERS WILL BE POSSIBLE THEREAFTER
FROM THE SAGINAW VALLEY TO EASTERN THUMB REGION...CLOSER TO THE
CENTER OF THE SURFACE LOW. MINS TONIGHT RANGE FROM THE UPPER 50 TO
LOW 60S. THERE IS POTENTIAL FOR AM FOG AGAIN TOMORROW...WHICH MAY BE
MITIGATED BY CIRRUS BLOWOFF FROM UPSTREAM WARM FRONTAL SYSTEM. AREAS
NORTH OF I-69 HOLD THE BETTER CHANCE FOR FOG DEVELOPMENT WITH LIGHT
WINDS AND INCREASED MOISTURE CONTENT.

LONG TERM...

LONGWAVE FEEDBACK ASSOCIATED WITH STRONG JET ENERGY DIGGING INTO THE
PAC NW AND INTERMOUNTAIN WEST WILL FORCE THE SUBTROPICAL RIDGE
ANCHORED OVER THE SOUTHERN UNITED STATES TO UNDERGO NOTEWORTHY
AMPLIFICATION HEADING INTO THE WEEKEND. DURING THIS TIME, SOUTHEAST
MICHIGAN WILL RESIDE ON THE EDGE OF THE INSTABILITY GRADIENT WITH NO
APPRECIABLE UPPER FORCING TO SPEAK OF. AS A RESULT, THE FORECAST
FEATURES SEVERAL PERIODS CONSISTING MAINLY OF CHANCE POPS TO ACCOUNT
FOR THE RATHER NEBULOUS PERIOD OF CONVECTIVE POTENTIAL.

DURING THE NEXT 48 HOURS, THE HIGHEST PROBABILITY SCENARIO WILL BE
FOR SOUTHEAST MICHIGAN TO FEAST UPON THE LEFTOVERS OF UPSTREAM
REMNANTS. HIGH RES SOLUTIONS SUGGEST THAT THIS WILL BE THE CASE ON
THURSDAY AS HIGH PLAINS REMNANTS PROPAGATE INTO THE OHIO VALLEY,
EXPERIENCING A DIURNAL FLARE-UP DURING THE DAY WHICH IS MOST LIKELY
TO OCCUR TO OUR SOUTH...OR AT LEAST SOUTH OF THE METRO AREA...GIVEN
THE PROGGED LOCATION OF HIGHER INSTABILITY. HOWEVER...DIURNAL
HEATING INVOF NORTHWARD ADVANCING WARM FRONT WILL PRESENT THE
OPPORTUNITY FOR ISOLATED TO PERHAPS SCATTERED THUNDERSTORM DEVELOP
DURING THE DAY. ADEQUATE SHEAR AROUND 35 KNOTS WILL BE SUFFICIENT TO
SUPPORT ORGANIZED UPDRAFTS DEPENDING ON CLOUD COVER/INSTABILITY, SO
A MARGINAL RISK FOR SEVERE WEATHER DOES EXIST.

A SIMILAR SITUATION WILL BE PRESENT THURSDAY NIGHT INTO FRIDAY
MORNING, EXCEPT WITH THE FAVORABLE THERMODYNAMIC ENVIRONMENT
CREEPING CLOSER. THE GENESIS REGION FOR ANY THURSDAY NIGHT ACTIVITY
WILL LIKELY BE INVOF THE APEX OF THE RIDGE/EDGE OF THE CAP SOMEWHERE
IN THE UPPER MS RIVER VALLEY PER PATTERN RECOGNITION/HIGH-RES MODEL
SIGNALS. MESOSCALE DETAILS THAT WILL NOT BECOME CLEAR UNTIL THURSDAY
OR THURSDAY NIGHT ENTER THE NEAR TERM WILL BE CRITICAL. THE
POTENTIAL FOR COLD POOL DEVELOPMENT AND MAINTENANCE WILL NEED TO BE
MONITORED AS IT WILL DETERMINE THE POTENTIAL FOR UPSCALE GROWTH AS
THIS ACTIVITY DIVES INTO THE LOWER PENINSULA, WHERE THE
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE - BUT NOT EXCEPTIONAL -
LATE THURSDAY NIGHT.

HIGH TEMPS WILL CREEP UPWARD THROUGH MUCH OF THE LONG TERM PERIOD AS
THE AFOREMENTIONED RIDGE AMPLIFIES AND H85 TEMPERATURES INCREASE
INTO THE UPPER TEENS BY FRIDAY...AND THEN FURTHER HEADING INTO THE
WEEKEND. NO ARGUMENTS WITH THE GUIDANCE WHICH SUGGESTS DAYTIME HIGHS
HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE UPPER 60S.

RAIN CHANCES WILL LIKELY STICK AROUND THROUGH NEXT WEEK AS A SERIES
OF SHORTWAVES TRACK OVER SOUTHEAST MICHIGAN. MODEL AGREEMENT IS
STILL QUITE LOW AND HAVE THEREFORE ONLY PUT IN LOW CHANCE POPS INTO
THE FORECAST THROUGH WEDNESDAY. TIMING AND COVERAGE OF THE RAIN WILL
BE REFINED AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES.
TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID TO UPPER 60S THROUGH WEDNESDAY.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THUNDERSTORM CHANCES WILL
PERSIST MAINLY FOR CENTRAL LAKE HURON AND POINTS SOUTH THROUGH THIS
EVENING. THERE IS THEN A CHANCE FOR THUNDERSTORMS FOR ALL MARINE
AREAS LATE THURSDAY NIGHT INTO EARLY FRIDAY...AND SEVERE WEATHER IS
NOT OUT OF THE QUESTION DURING THIS TIME. MODERATE SOUTHWESTERLY
FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT A
MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

AVIATION.....BT
UPDATE.......BT
SHORT TERM...MM
LONG TERM....JVC/RK
MARINE.......JVC


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









000
FXUS63 KDTX 210405
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1205 AM EDT THU AUG 21 2014

.AVIATION...

//DISCUSSION...

THE CLOUD PATTERN LEADING UP TO MIDNIGHT CONTINUES TO FAVOR MBS AND
FNT AS THE MOST LIKELY LOCATIONS FOR IFR FOG AND PERHAPS EVEN A LOW
END MVFR OR IFR CEILING BEFORE SUNRISE. EXPECT IFR CONDITIONS TO
RESULT IN SIMILAR RESTRICTION TO WEDNESDAY MORNING FOLLOWED BY A
TYPICAL TREND OF MORNING IMPROVEMENT. THE FOG SITUATION IN THE DTW
AREA WILL BE MITIGATED BY AN INCREASE IN MID CLOUDS ASSOCIATED WITH
THE WARM FRONT DEVELOPING UPSTREAM. A ROUND OF SHOWERS IS THEN
EXPECTED DURING THE LATE AFTERNOON INTO THURSDAY EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET WITH SHOWERS BY LATE
AFTERNOON THROUGH THURSDAY EVENING.

&&

.PREV DISCUSSION...ISSUED 943 PM EDT WED AUG 20 2014

UPDATE...

A COUPLE OF THINGS TO MONITOR DURING THE NIGHT THROUGH THURSDAY
MORNING INCLUDE FOG POTENTIAL AND THE CHANCE OF SHOWERS
REDEVELOPING LATER IN THE NIGHT. AS FOR FOG...WE ARE STARTING OUT
TONIGHT WITH A SIMILAR BOUNDARY LAYER MOISTURE PROFILE BUT A FEW
DEGREES WARMER THAN LAST NIGHT. THERE IS ALSO LESS CLOUD COVER BUT
NOT AS MUCH WET GROUND. THINKING THE GOING FORECAST HAS THE
SITUATION COVERED WELL WITH AREAS OF FOG ALONG AND NORTH OF I-69.
THIS IS WHERE SHOWER COVERAGE WAS GREATEST DURING THE DAY AND WHERE
THE SKY WILL REMAIN CLEAR THE LONGEST AS THE WIND GOES LIGHT AND
VARIABLE TONIGHT. SOUTH OF THERE...TEMP/DEWPOINT SPREAD IS
GREATER AND CLOUDS WILL INCREASE AGAIN EARLIER IN THE FORM OF
CIRRUS AND ALTOCU. THERE COULD EVEN BE A HIGH-BASED SHOWER AS FAR
NORTH AS I-96 CONSIDERING THE STRENGTH OF THE MID LEVEL THETA-E
ADVECTION BY SUNRISE.

PREV DISCUSSION...ISSUED 323 PM EDT WED AUG 20 2014

SHORT TERM...TONIGHT

STACKED LOW PRESSURE CONTINUES TO CHURN OVER NORTHERN MICHIGAN THIS
EVENING. THE UPPER LOW WILL PIVOT SOME THIS EVENING TO CREATE A
NEGATIVE TILT WITHIN THE BROAD 500MB TROUGH PATTERN TONIGHT. AS THE
FEATURE TILTS...AN AREA OF SURFACE CONVERGENCE WILL HELP SPARK
CONTINUED SHOWERS WITH ISOLATED THUNDERSTORMS. WHILE THERE IS A
FORECASTED MAXIMUM OF 25KT H85 WINDS OVER SRN MI THIS EVENING...THE
OVERALL FLOW IS VERY WEAK. THIS WILL LEAD TO SLOW MOVING SINGLE
CELLS. BOTH MOISTURE CONTENT AND INSTABILITY ARE MODEST TODAY /1.5
INCH PWAT AND 1500 J/KG CAPE/ BUT ARE AMPLE TO PRODUCE SOME
CONVECTION WITH LITTLE POTENTIAL FOR DAMAGING WINDS OR HAIL. 0-6 KM
BULK SHEAR OF 25 KT IS UNIDIRECTIONAL...LEADING TO LITTLE RISK FOR
ROTATION TODAY.

THE DIURNALLY DRIVEN CONVECTION WILL COME TO AN END AFTER 01Z THIS
EVENING. JUST A FEW ISOLATED SHOWERS WILL BE POSSIBLE THEREAFTER
FROM THE SAGINAW VALLEY TO EASTERN THUMB REGION...CLOSER TO THE
CENTER OF THE SURFACE LOW. MINS TONIGHT RANGE FROM THE UPPER 50 TO
LOW 60S. THERE IS POTENTIAL FOR AM FOG AGAIN TOMORROW...WHICH MAY BE
MITIGATED BY CIRRUS BLOWOFF FROM UPSTREAM WARM FRONTAL SYSTEM. AREAS
NORTH OF I-69 HOLD THE BETTER CHANCE FOR FOG DEVELOPMENT WITH LIGHT
WINDS AND INCREASED MOISTURE CONTENT.

LONG TERM...

LONGWAVE FEEDBACK ASSOCIATED WITH STRONG JET ENERGY DIGGING INTO THE
PAC NW AND INTERMOUNTAIN WEST WILL FORCE THE SUBTROPICAL RIDGE
ANCHORED OVER THE SOUTHERN UNITED STATES TO UNDERGO NOTEWORTHY
AMPLIFICATION HEADING INTO THE WEEKEND. DURING THIS TIME, SOUTHEAST
MICHIGAN WILL RESIDE ON THE EDGE OF THE INSTABILITY GRADIENT WITH NO
APPRECIABLE UPPER FORCING TO SPEAK OF. AS A RESULT, THE FORECAST
FEATURES SEVERAL PERIODS CONSISTING MAINLY OF CHANCE POPS TO ACCOUNT
FOR THE RATHER NEBULOUS PERIOD OF CONVECTIVE POTENTIAL.

DURING THE NEXT 48 HOURS, THE HIGHEST PROBABILITY SCENARIO WILL BE
FOR SOUTHEAST MICHIGAN TO FEAST UPON THE LEFTOVERS OF UPSTREAM
REMNANTS. HIGH RES SOLUTIONS SUGGEST THAT THIS WILL BE THE CASE ON
THURSDAY AS HIGH PLAINS REMNANTS PROPAGATE INTO THE OHIO VALLEY,
EXPERIENCING A DIURNAL FLARE-UP DURING THE DAY WHICH IS MOST LIKELY
TO OCCUR TO OUR SOUTH...OR AT LEAST SOUTH OF THE METRO AREA...GIVEN
THE PROGGED LOCATION OF HIGHER INSTABILITY. HOWEVER...DIURNAL
HEATING INVOF NORTHWARD ADVANCING WARM FRONT WILL PRESENT THE
OPPORTUNITY FOR ISOLATED TO PERHAPS SCATTERED THUNDERSTORM DEVELOP
DURING THE DAY. ADEQUATE SHEAR AROUND 35 KNOTS WILL BE SUFFICIENT TO
SUPPORT ORGANIZED UPDRAFTS DEPENDING ON CLOUD COVER/INSTABILITY, SO
A MARGINAL RISK FOR SEVERE WEATHER DOES EXIST.

A SIMILAR SITUATION WILL BE PRESENT THURSDAY NIGHT INTO FRIDAY
MORNING, EXCEPT WITH THE FAVORABLE THERMODYNAMIC ENVIRONMENT
CREEPING CLOSER. THE GENESIS REGION FOR ANY THURSDAY NIGHT ACTIVITY
WILL LIKELY BE INVOF THE APEX OF THE RIDGE/EDGE OF THE CAP SOMEWHERE
IN THE UPPER MS RIVER VALLEY PER PATTERN RECOGNITION/HIGH-RES MODEL
SIGNALS. MESOSCALE DETAILS THAT WILL NOT BECOME CLEAR UNTIL THURSDAY
OR THURSDAY NIGHT ENTER THE NEAR TERM WILL BE CRITICAL. THE
POTENTIAL FOR COLD POOL DEVELOPMENT AND MAINTENANCE WILL NEED TO BE
MONITORED AS IT WILL DETERMINE THE POTENTIAL FOR UPSCALE GROWTH AS
THIS ACTIVITY DIVES INTO THE LOWER PENINSULA, WHERE THE
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE - BUT NOT EXCEPTIONAL -
LATE THURSDAY NIGHT.

HIGH TEMPS WILL CREEP UPWARD THROUGH MUCH OF THE LONG TERM PERIOD AS
THE AFOREMENTIONED RIDGE AMPLIFIES AND H85 TEMPERATURES INCREASE
INTO THE UPPER TEENS BY FRIDAY...AND THEN FURTHER HEADING INTO THE
WEEKEND. NO ARGUMENTS WITH THE GUIDANCE WHICH SUGGESTS DAYTIME HIGHS
HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE UPPER 60S.

RAIN CHANCES WILL LIKELY STICK AROUND THROUGH NEXT WEEK AS A SERIES
OF SHORTWAVES TRACK OVER SOUTHEAST MICHIGAN. MODEL AGREEMENT IS
STILL QUITE LOW AND HAVE THEREFORE ONLY PUT IN LOW CHANCE POPS INTO
THE FORECAST THROUGH WEDNESDAY. TIMING AND COVERAGE OF THE RAIN WILL
BE REFINED AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES.
TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID TO UPPER 60S THROUGH WEDNESDAY.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THUNDERSTORM CHANCES WILL
PERSIST MAINLY FOR CENTRAL LAKE HURON AND POINTS SOUTH THROUGH THIS
EVENING. THERE IS THEN A CHANCE FOR THUNDERSTORMS FOR ALL MARINE
AREAS LATE THURSDAY NIGHT INTO EARLY FRIDAY...AND SEVERE WEATHER IS
NOT OUT OF THE QUESTION DURING THIS TIME. MODERATE SOUTHWESTERLY
FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT A
MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

AVIATION.....BT
UPDATE.......BT
SHORT TERM...MM
LONG TERM....JVC/RK
MARINE.......JVC


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









000
FXUS63 KDTX 210405
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1205 AM EDT THU AUG 21 2014

.AVIATION...

//DISCUSSION...

THE CLOUD PATTERN LEADING UP TO MIDNIGHT CONTINUES TO FAVOR MBS AND
FNT AS THE MOST LIKELY LOCATIONS FOR IFR FOG AND PERHAPS EVEN A LOW
END MVFR OR IFR CEILING BEFORE SUNRISE. EXPECT IFR CONDITIONS TO
RESULT IN SIMILAR RESTRICTION TO WEDNESDAY MORNING FOLLOWED BY A
TYPICAL TREND OF MORNING IMPROVEMENT. THE FOG SITUATION IN THE DTW
AREA WILL BE MITIGATED BY AN INCREASE IN MID CLOUDS ASSOCIATED WITH
THE WARM FRONT DEVELOPING UPSTREAM. A ROUND OF SHOWERS IS THEN
EXPECTED DURING THE LATE AFTERNOON INTO THURSDAY EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET WITH SHOWERS BY LATE
AFTERNOON THROUGH THURSDAY EVENING.

&&

.PREV DISCUSSION...ISSUED 943 PM EDT WED AUG 20 2014

UPDATE...

A COUPLE OF THINGS TO MONITOR DURING THE NIGHT THROUGH THURSDAY
MORNING INCLUDE FOG POTENTIAL AND THE CHANCE OF SHOWERS
REDEVELOPING LATER IN THE NIGHT. AS FOR FOG...WE ARE STARTING OUT
TONIGHT WITH A SIMILAR BOUNDARY LAYER MOISTURE PROFILE BUT A FEW
DEGREES WARMER THAN LAST NIGHT. THERE IS ALSO LESS CLOUD COVER BUT
NOT AS MUCH WET GROUND. THINKING THE GOING FORECAST HAS THE
SITUATION COVERED WELL WITH AREAS OF FOG ALONG AND NORTH OF I-69.
THIS IS WHERE SHOWER COVERAGE WAS GREATEST DURING THE DAY AND WHERE
THE SKY WILL REMAIN CLEAR THE LONGEST AS THE WIND GOES LIGHT AND
VARIABLE TONIGHT. SOUTH OF THERE...TEMP/DEWPOINT SPREAD IS
GREATER AND CLOUDS WILL INCREASE AGAIN EARLIER IN THE FORM OF
CIRRUS AND ALTOCU. THERE COULD EVEN BE A HIGH-BASED SHOWER AS FAR
NORTH AS I-96 CONSIDERING THE STRENGTH OF THE MID LEVEL THETA-E
ADVECTION BY SUNRISE.

PREV DISCUSSION...ISSUED 323 PM EDT WED AUG 20 2014

SHORT TERM...TONIGHT

STACKED LOW PRESSURE CONTINUES TO CHURN OVER NORTHERN MICHIGAN THIS
EVENING. THE UPPER LOW WILL PIVOT SOME THIS EVENING TO CREATE A
NEGATIVE TILT WITHIN THE BROAD 500MB TROUGH PATTERN TONIGHT. AS THE
FEATURE TILTS...AN AREA OF SURFACE CONVERGENCE WILL HELP SPARK
CONTINUED SHOWERS WITH ISOLATED THUNDERSTORMS. WHILE THERE IS A
FORECASTED MAXIMUM OF 25KT H85 WINDS OVER SRN MI THIS EVENING...THE
OVERALL FLOW IS VERY WEAK. THIS WILL LEAD TO SLOW MOVING SINGLE
CELLS. BOTH MOISTURE CONTENT AND INSTABILITY ARE MODEST TODAY /1.5
INCH PWAT AND 1500 J/KG CAPE/ BUT ARE AMPLE TO PRODUCE SOME
CONVECTION WITH LITTLE POTENTIAL FOR DAMAGING WINDS OR HAIL. 0-6 KM
BULK SHEAR OF 25 KT IS UNIDIRECTIONAL...LEADING TO LITTLE RISK FOR
ROTATION TODAY.

THE DIURNALLY DRIVEN CONVECTION WILL COME TO AN END AFTER 01Z THIS
EVENING. JUST A FEW ISOLATED SHOWERS WILL BE POSSIBLE THEREAFTER
FROM THE SAGINAW VALLEY TO EASTERN THUMB REGION...CLOSER TO THE
CENTER OF THE SURFACE LOW. MINS TONIGHT RANGE FROM THE UPPER 50 TO
LOW 60S. THERE IS POTENTIAL FOR AM FOG AGAIN TOMORROW...WHICH MAY BE
MITIGATED BY CIRRUS BLOWOFF FROM UPSTREAM WARM FRONTAL SYSTEM. AREAS
NORTH OF I-69 HOLD THE BETTER CHANCE FOR FOG DEVELOPMENT WITH LIGHT
WINDS AND INCREASED MOISTURE CONTENT.

LONG TERM...

LONGWAVE FEEDBACK ASSOCIATED WITH STRONG JET ENERGY DIGGING INTO THE
PAC NW AND INTERMOUNTAIN WEST WILL FORCE THE SUBTROPICAL RIDGE
ANCHORED OVER THE SOUTHERN UNITED STATES TO UNDERGO NOTEWORTHY
AMPLIFICATION HEADING INTO THE WEEKEND. DURING THIS TIME, SOUTHEAST
MICHIGAN WILL RESIDE ON THE EDGE OF THE INSTABILITY GRADIENT WITH NO
APPRECIABLE UPPER FORCING TO SPEAK OF. AS A RESULT, THE FORECAST
FEATURES SEVERAL PERIODS CONSISTING MAINLY OF CHANCE POPS TO ACCOUNT
FOR THE RATHER NEBULOUS PERIOD OF CONVECTIVE POTENTIAL.

DURING THE NEXT 48 HOURS, THE HIGHEST PROBABILITY SCENARIO WILL BE
FOR SOUTHEAST MICHIGAN TO FEAST UPON THE LEFTOVERS OF UPSTREAM
REMNANTS. HIGH RES SOLUTIONS SUGGEST THAT THIS WILL BE THE CASE ON
THURSDAY AS HIGH PLAINS REMNANTS PROPAGATE INTO THE OHIO VALLEY,
EXPERIENCING A DIURNAL FLARE-UP DURING THE DAY WHICH IS MOST LIKELY
TO OCCUR TO OUR SOUTH...OR AT LEAST SOUTH OF THE METRO AREA...GIVEN
THE PROGGED LOCATION OF HIGHER INSTABILITY. HOWEVER...DIURNAL
HEATING INVOF NORTHWARD ADVANCING WARM FRONT WILL PRESENT THE
OPPORTUNITY FOR ISOLATED TO PERHAPS SCATTERED THUNDERSTORM DEVELOP
DURING THE DAY. ADEQUATE SHEAR AROUND 35 KNOTS WILL BE SUFFICIENT TO
SUPPORT ORGANIZED UPDRAFTS DEPENDING ON CLOUD COVER/INSTABILITY, SO
A MARGINAL RISK FOR SEVERE WEATHER DOES EXIST.

A SIMILAR SITUATION WILL BE PRESENT THURSDAY NIGHT INTO FRIDAY
MORNING, EXCEPT WITH THE FAVORABLE THERMODYNAMIC ENVIRONMENT
CREEPING CLOSER. THE GENESIS REGION FOR ANY THURSDAY NIGHT ACTIVITY
WILL LIKELY BE INVOF THE APEX OF THE RIDGE/EDGE OF THE CAP SOMEWHERE
IN THE UPPER MS RIVER VALLEY PER PATTERN RECOGNITION/HIGH-RES MODEL
SIGNALS. MESOSCALE DETAILS THAT WILL NOT BECOME CLEAR UNTIL THURSDAY
OR THURSDAY NIGHT ENTER THE NEAR TERM WILL BE CRITICAL. THE
POTENTIAL FOR COLD POOL DEVELOPMENT AND MAINTENANCE WILL NEED TO BE
MONITORED AS IT WILL DETERMINE THE POTENTIAL FOR UPSCALE GROWTH AS
THIS ACTIVITY DIVES INTO THE LOWER PENINSULA, WHERE THE
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE - BUT NOT EXCEPTIONAL -
LATE THURSDAY NIGHT.

HIGH TEMPS WILL CREEP UPWARD THROUGH MUCH OF THE LONG TERM PERIOD AS
THE AFOREMENTIONED RIDGE AMPLIFIES AND H85 TEMPERATURES INCREASE
INTO THE UPPER TEENS BY FRIDAY...AND THEN FURTHER HEADING INTO THE
WEEKEND. NO ARGUMENTS WITH THE GUIDANCE WHICH SUGGESTS DAYTIME HIGHS
HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE UPPER 60S.

RAIN CHANCES WILL LIKELY STICK AROUND THROUGH NEXT WEEK AS A SERIES
OF SHORTWAVES TRACK OVER SOUTHEAST MICHIGAN. MODEL AGREEMENT IS
STILL QUITE LOW AND HAVE THEREFORE ONLY PUT IN LOW CHANCE POPS INTO
THE FORECAST THROUGH WEDNESDAY. TIMING AND COVERAGE OF THE RAIN WILL
BE REFINED AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES.
TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID TO UPPER 60S THROUGH WEDNESDAY.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THUNDERSTORM CHANCES WILL
PERSIST MAINLY FOR CENTRAL LAKE HURON AND POINTS SOUTH THROUGH THIS
EVENING. THERE IS THEN A CHANCE FOR THUNDERSTORMS FOR ALL MARINE
AREAS LATE THURSDAY NIGHT INTO EARLY FRIDAY...AND SEVERE WEATHER IS
NOT OUT OF THE QUESTION DURING THIS TIME. MODERATE SOUTHWESTERLY
FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT A
MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

AVIATION.....BT
UPDATE.......BT
SHORT TERM...MM
LONG TERM....JVC/RK
MARINE.......JVC


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








000
FXUS63 KDTX 210143
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
943 PM EDT WED AUG 20 2014

.UPDATE...

A COUPLE OF THINGS TO MONITOR DURING THE NIGHT THROUGH THURSDAY
MORNING INCLUDE FOG POTENTIAL AND THE CHANCE OF SHOWERS
REDEVELOPING LATER IN THE NIGHT. AS FOR FOG...WE ARE STARTING OUT
TONIGHT WITH A SIMILAR BOUNDARY LAYER MOISTURE PROFILE BUT A FEW
DEGREES WARMER THAN LAST NIGHT. THERE IS ALSO LESS CLOUD COVER BUT
NOT AS MUCH WET GROUND. THINKING THE GOING FORECAST HAS THE
SITUATION COVERED WELL WITH AREAS OF FOG ALONG AND NORTH OF I-69.
THIS IS WHERE SHOWER COVERAGE WAS GREATEST DURING THE DAY AND WHERE
THE SKY WILL REMAIN CLEAR THE LONGEST AS THE WIND GOES LIGHT AND
VARIABLE TONIGHT. SOUTH OF THERE...TEMP/DEWPOINT SPREAD IS
GREATER AND CLOUDS WILL INCREASE AGAIN EARLIER IN THE FORM OF
CIRRUS AND ALTOCU. THERE COULD EVEN BE A HIGH-BASED SHOWER AS FAR
NORTH AS I-96 CONSIDERING THE STRENGTH OF THE MID LEVEL THETA-E
ADVECTION BY SUNRISE.

&&

.AVIATION...ISSUED 717 PM EDT WED AUG 20 2014

//DISCUSSION...

EARLY EVENING OBSERVATIONS INDICATE SHOWERS AND THUNDERSTORMS
DIMINISHING RAPIDLY WITH THE LOSS OF DAYTIME HEATING AND A
SUBSTANTIAL LOSS OF CLOUD COVER AS WELL. THIS WILL LEAVE VFR
CONDITIONS IN PLACE AT ALL TERMINALS THROUGH MIDNIGHT BEFORE OPEN
SKY WITH LIGHT AND VARIABLE WIND PROMOTES ANOTHER ROUND OF FOG.
EXPECT IFR CONDITIONS TO RESULT IN SIMILAR RESTRICTION TO LAST
NIGHT BUT WITH LESS STRATUS AND MORE OF A FOG COMPONENT. A TYPICAL
TREND OF MORNING IMPROVEMENT IN VISIBILITY IS EXPECTED ALONG WITH
ANOTHER ROUND OF SHOWERS AND STORMS MAINLY DURING LATE THURSDAY
AFTERNOON INTO THE EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AS FOG LIFTS THURSDAY
MORNING.

* LOW CONFIDENCE IN 200 FT CEILING AND 1/2 SM VISIBILITY.

&&

.PREV DISCUSSION...ISSUED 323 PM EDT WED AUG 20 2014

SHORT TERM...TONIGHT

STACKED LOW PRESSURE CONTINUES TO CHURN OVER NORTHERN MICHIGAN THIS
EVENING. THE UPPER LOW WILL PIVOT SOME THIS EVENING TO CREATE A
NEGATIVE TILT WITHIN THE BROAD 500MB TROUGH PATTERN TONIGHT. AS THE
FEATURE TILTS...AN AREA OF SURFACE CONVERGENCE WILL HELP SPARK
CONTINUED SHOWERS WITH ISOLATED THUNDERSTORMS. WHILE THERE IS A
FORECASTED MAXIMUM OF 25KT H85 WINDS OVER SRN MI THIS EVENING...THE
OVERALL FLOW IS VERY WEAK. THIS WILL LEAD TO SLOW MOVING SINGLE
CELLS. BOTH MOISTURE CONTENT AND INSTABILITY ARE MODEST TODAY /1.5
INCH PWAT AND 1500 J/KG CAPE/ BUT ARE AMPLE TO PRODUCE SOME
CONVECTION WITH LITTLE POTENTIAL FOR DAMAGING WINDS OR HAIL. 0-6 KM
BULK SHEAR OF 25 KT IS UNIDIRECTIONAL...LEADING TO LITTLE RISK FOR
ROTATION TODAY.

THE DIURNALLY DRIVEN CONVECTION WILL COME TO AN END AFTER 01Z THIS
EVENING. JUST A FEW ISOLATED SHOWERS WILL BE POSSIBLE THEREAFTER
FROM THE SAGINAW VALLEY TO EASTERN THUMB REGION...CLOSER TO THE
CENTER OF THE SURFACE LOW. MINS TONIGHT RANGE FROM THE UPPER 50 TO
LOW 60S. THERE IS POTENTIAL FOR AM FOG AGAIN TOMORROW...WHICH MAY BE
MITIGATED BY CIRRUS BLOWOFF FROM UPSTREAM WARM FRONTAL SYSTEM. AREAS
NORTH OF I-69 HOLD THE BETTER CHANCE FOR FOG DEVELOPMENT WITH LIGHT
WINDS AND INCREASED MOISTURE CONTENT.

LONG TERM...

LONGWAVE FEEDBACK ASSOCIATED WITH STRONG JET ENERGY DIGGING INTO THE
PAC NW AND INTERMOUNTAIN WEST WILL FORCE THE SUBTROPICAL RIDGE
ANCHORED OVER THE SOUTHERN UNITED STATES TO UNDERGO NOTEWORTHY
AMPLIFICATION HEADING INTO THE WEEKEND. DURING THIS TIME, SOUTHEAST
MICHIGAN WILL RESIDE ON THE EDGE OF THE INSTABILITY GRADIENT WITH NO
APPRECIABLE UPPER FORCING TO SPEAK OF. AS A RESULT, THE FORECAST
FEATURES SEVERAL PERIODS CONSISTING MAINLY OF CHANCE POPS TO ACCOUNT
FOR THE RATHER NEBULOUS PERIOD OF CONVECTIVE POTENTIAL.

DURING THE NEXT 48 HOURS, THE HIGHEST PROBABILITY SCENARIO WILL BE
FOR SOUTHEAST MICHIGAN TO FEAST UPON THE LEFTOVERS OF UPSTREAM
REMNANTS. HIGH RES SOLUTIONS SUGGEST THAT THIS WILL BE THE CASE ON
THURSDAY AS HIGH PLAINS REMNANTS PROPAGATE INTO THE OHIO VALLEY,
EXPERIENCING A DIURNAL FLARE-UP DURING THE DAY WHICH IS MOST LIKELY
TO OCCUR TO OUR SOUTH...OR AT LEAST SOUTH OF THE METRO AREA...GIVEN
THE PROGGED LOCATION OF HIGHER INSTABILITY. HOWEVER...DIURNAL
HEATING INVOF NORTHWARD ADVANCING WARM FRONT WILL PRESENT THE
OPPORTUNITY FOR ISOLATED TO PERHAPS SCATTERED THUNDERSTORM DEVELOP
DURING THE DAY. ADEQUATE SHEAR AROUND 35 KNOTS WILL BE SUFFICIENT TO
SUPPORT ORGANIZED UPDRAFTS DEPENDING ON CLOUD COVER/INSTABILITY, SO
A MARGINAL RISK FOR SEVERE WEATHER DOES EXIST.

A SIMILAR SITUATION WILL BE PRESENT THURSDAY NIGHT INTO FRIDAY
MORNING, EXCEPT WITH THE FAVORABLE THERMODYNAMIC ENVIRONMENT
CREEPING CLOSER. THE GENESIS REGION FOR ANY THURSDAY NIGHT ACTIVITY
WILL LIKELY BE INVOF THE APEX OF THE RIDGE/EDGE OF THE CAP SOMEWHERE
IN THE UPPER MS RIVER VALLEY PER PATTERN RECOGNITION/HIGH-RES MODEL
SIGNALS. MESOSCALE DETAILS THAT WILL NOT BECOME CLEAR UNTIL THURSDAY
OR THURSDAY NIGHT ENTER THE NEAR TERM WILL BE CRITICAL. THE
POTENTIAL FOR COLD POOL DEVELOPMENT AND MAINTENANCE WILL NEED TO BE
MONITORED AS IT WILL DETERMINE THE POTENTIAL FOR UPSCALE GROWTH AS
THIS ACTIVITY DIVES INTO THE LOWER PENINSULA, WHERE THE
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE - BUT NOT EXCEPTIONAL -
LATE THURSDAY NIGHT.

HIGH TEMPS WILL CREEP UPWARD THROUGH MUCH OF THE LONG TERM PERIOD AS
THE AFOREMENTIONED RIDGE AMPLIFIES AND H85 TEMPERATURES INCREASE
INTO THE UPPER TEENS BY FRIDAY...AND THEN FURTHER HEADING INTO THE
WEEKEND. NO ARGUMENTS WITH THE GUIDANCE WHICH SUGGESTS DAYTIME HIGHS
HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE UPPER 60S.

RAIN CHANCES WILL LIKELY STICK AROUND THROUGH NEXT WEEK AS A SERIES
OF SHORTWAVES TRACK OVER SOUTHEAST MICHIGAN. MODEL AGREEMENT IS
STILL QUITE LOW AND HAVE THEREFORE ONLY PUT IN LOW CHANCE POPS INTO
THE FORECAST THROUGH WEDNESDAY. TIMING AND COVERAGE OF THE RAIN WILL
BE REFINED AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES.
TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID TO UPPER 60S THROUGH WEDNESDAY.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THUNDERSTORM CHANCES WILL
PERSIST MAINLY FOR CENTRAL LAKE HURON AND POINTS SOUTH THROUGH THIS
EVENING. THERE IS THEN A CHANCE FOR THUNDERSTORMS FOR ALL MARINE
AREAS LATE THURSDAY NIGHT INTO EARLY FRIDAY...AND SEVERE WEATHER IS
NOT OUT OF THE QUESTION DURING THIS TIME. MODERATE SOUTHWESTERLY
FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT A
MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

UPDATE.......BT
AVIATION.....BT
SHORT TERM...MM
LONG TERM....JVC/RK
MARINE.......JVC


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










000
FXUS63 KDTX 210143
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
943 PM EDT WED AUG 20 2014

.UPDATE...

A COUPLE OF THINGS TO MONITOR DURING THE NIGHT THROUGH THURSDAY
MORNING INCLUDE FOG POTENTIAL AND THE CHANCE OF SHOWERS
REDEVELOPING LATER IN THE NIGHT. AS FOR FOG...WE ARE STARTING OUT
TONIGHT WITH A SIMILAR BOUNDARY LAYER MOISTURE PROFILE BUT A FEW
DEGREES WARMER THAN LAST NIGHT. THERE IS ALSO LESS CLOUD COVER BUT
NOT AS MUCH WET GROUND. THINKING THE GOING FORECAST HAS THE
SITUATION COVERED WELL WITH AREAS OF FOG ALONG AND NORTH OF I-69.
THIS IS WHERE SHOWER COVERAGE WAS GREATEST DURING THE DAY AND WHERE
THE SKY WILL REMAIN CLEAR THE LONGEST AS THE WIND GOES LIGHT AND
VARIABLE TONIGHT. SOUTH OF THERE...TEMP/DEWPOINT SPREAD IS
GREATER AND CLOUDS WILL INCREASE AGAIN EARLIER IN THE FORM OF
CIRRUS AND ALTOCU. THERE COULD EVEN BE A HIGH-BASED SHOWER AS FAR
NORTH AS I-96 CONSIDERING THE STRENGTH OF THE MID LEVEL THETA-E
ADVECTION BY SUNRISE.

&&

.AVIATION...ISSUED 717 PM EDT WED AUG 20 2014

//DISCUSSION...

EARLY EVENING OBSERVATIONS INDICATE SHOWERS AND THUNDERSTORMS
DIMINISHING RAPIDLY WITH THE LOSS OF DAYTIME HEATING AND A
SUBSTANTIAL LOSS OF CLOUD COVER AS WELL. THIS WILL LEAVE VFR
CONDITIONS IN PLACE AT ALL TERMINALS THROUGH MIDNIGHT BEFORE OPEN
SKY WITH LIGHT AND VARIABLE WIND PROMOTES ANOTHER ROUND OF FOG.
EXPECT IFR CONDITIONS TO RESULT IN SIMILAR RESTRICTION TO LAST
NIGHT BUT WITH LESS STRATUS AND MORE OF A FOG COMPONENT. A TYPICAL
TREND OF MORNING IMPROVEMENT IN VISIBILITY IS EXPECTED ALONG WITH
ANOTHER ROUND OF SHOWERS AND STORMS MAINLY DURING LATE THURSDAY
AFTERNOON INTO THE EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AS FOG LIFTS THURSDAY
MORNING.

* LOW CONFIDENCE IN 200 FT CEILING AND 1/2 SM VISIBILITY.

&&

.PREV DISCUSSION...ISSUED 323 PM EDT WED AUG 20 2014

SHORT TERM...TONIGHT

STACKED LOW PRESSURE CONTINUES TO CHURN OVER NORTHERN MICHIGAN THIS
EVENING. THE UPPER LOW WILL PIVOT SOME THIS EVENING TO CREATE A
NEGATIVE TILT WITHIN THE BROAD 500MB TROUGH PATTERN TONIGHT. AS THE
FEATURE TILTS...AN AREA OF SURFACE CONVERGENCE WILL HELP SPARK
CONTINUED SHOWERS WITH ISOLATED THUNDERSTORMS. WHILE THERE IS A
FORECASTED MAXIMUM OF 25KT H85 WINDS OVER SRN MI THIS EVENING...THE
OVERALL FLOW IS VERY WEAK. THIS WILL LEAD TO SLOW MOVING SINGLE
CELLS. BOTH MOISTURE CONTENT AND INSTABILITY ARE MODEST TODAY /1.5
INCH PWAT AND 1500 J/KG CAPE/ BUT ARE AMPLE TO PRODUCE SOME
CONVECTION WITH LITTLE POTENTIAL FOR DAMAGING WINDS OR HAIL. 0-6 KM
BULK SHEAR OF 25 KT IS UNIDIRECTIONAL...LEADING TO LITTLE RISK FOR
ROTATION TODAY.

THE DIURNALLY DRIVEN CONVECTION WILL COME TO AN END AFTER 01Z THIS
EVENING. JUST A FEW ISOLATED SHOWERS WILL BE POSSIBLE THEREAFTER
FROM THE SAGINAW VALLEY TO EASTERN THUMB REGION...CLOSER TO THE
CENTER OF THE SURFACE LOW. MINS TONIGHT RANGE FROM THE UPPER 50 TO
LOW 60S. THERE IS POTENTIAL FOR AM FOG AGAIN TOMORROW...WHICH MAY BE
MITIGATED BY CIRRUS BLOWOFF FROM UPSTREAM WARM FRONTAL SYSTEM. AREAS
NORTH OF I-69 HOLD THE BETTER CHANCE FOR FOG DEVELOPMENT WITH LIGHT
WINDS AND INCREASED MOISTURE CONTENT.

LONG TERM...

LONGWAVE FEEDBACK ASSOCIATED WITH STRONG JET ENERGY DIGGING INTO THE
PAC NW AND INTERMOUNTAIN WEST WILL FORCE THE SUBTROPICAL RIDGE
ANCHORED OVER THE SOUTHERN UNITED STATES TO UNDERGO NOTEWORTHY
AMPLIFICATION HEADING INTO THE WEEKEND. DURING THIS TIME, SOUTHEAST
MICHIGAN WILL RESIDE ON THE EDGE OF THE INSTABILITY GRADIENT WITH NO
APPRECIABLE UPPER FORCING TO SPEAK OF. AS A RESULT, THE FORECAST
FEATURES SEVERAL PERIODS CONSISTING MAINLY OF CHANCE POPS TO ACCOUNT
FOR THE RATHER NEBULOUS PERIOD OF CONVECTIVE POTENTIAL.

DURING THE NEXT 48 HOURS, THE HIGHEST PROBABILITY SCENARIO WILL BE
FOR SOUTHEAST MICHIGAN TO FEAST UPON THE LEFTOVERS OF UPSTREAM
REMNANTS. HIGH RES SOLUTIONS SUGGEST THAT THIS WILL BE THE CASE ON
THURSDAY AS HIGH PLAINS REMNANTS PROPAGATE INTO THE OHIO VALLEY,
EXPERIENCING A DIURNAL FLARE-UP DURING THE DAY WHICH IS MOST LIKELY
TO OCCUR TO OUR SOUTH...OR AT LEAST SOUTH OF THE METRO AREA...GIVEN
THE PROGGED LOCATION OF HIGHER INSTABILITY. HOWEVER...DIURNAL
HEATING INVOF NORTHWARD ADVANCING WARM FRONT WILL PRESENT THE
OPPORTUNITY FOR ISOLATED TO PERHAPS SCATTERED THUNDERSTORM DEVELOP
DURING THE DAY. ADEQUATE SHEAR AROUND 35 KNOTS WILL BE SUFFICIENT TO
SUPPORT ORGANIZED UPDRAFTS DEPENDING ON CLOUD COVER/INSTABILITY, SO
A MARGINAL RISK FOR SEVERE WEATHER DOES EXIST.

A SIMILAR SITUATION WILL BE PRESENT THURSDAY NIGHT INTO FRIDAY
MORNING, EXCEPT WITH THE FAVORABLE THERMODYNAMIC ENVIRONMENT
CREEPING CLOSER. THE GENESIS REGION FOR ANY THURSDAY NIGHT ACTIVITY
WILL LIKELY BE INVOF THE APEX OF THE RIDGE/EDGE OF THE CAP SOMEWHERE
IN THE UPPER MS RIVER VALLEY PER PATTERN RECOGNITION/HIGH-RES MODEL
SIGNALS. MESOSCALE DETAILS THAT WILL NOT BECOME CLEAR UNTIL THURSDAY
OR THURSDAY NIGHT ENTER THE NEAR TERM WILL BE CRITICAL. THE
POTENTIAL FOR COLD POOL DEVELOPMENT AND MAINTENANCE WILL NEED TO BE
MONITORED AS IT WILL DETERMINE THE POTENTIAL FOR UPSCALE GROWTH AS
THIS ACTIVITY DIVES INTO THE LOWER PENINSULA, WHERE THE
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE - BUT NOT EXCEPTIONAL -
LATE THURSDAY NIGHT.

HIGH TEMPS WILL CREEP UPWARD THROUGH MUCH OF THE LONG TERM PERIOD AS
THE AFOREMENTIONED RIDGE AMPLIFIES AND H85 TEMPERATURES INCREASE
INTO THE UPPER TEENS BY FRIDAY...AND THEN FURTHER HEADING INTO THE
WEEKEND. NO ARGUMENTS WITH THE GUIDANCE WHICH SUGGESTS DAYTIME HIGHS
HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE UPPER 60S.

RAIN CHANCES WILL LIKELY STICK AROUND THROUGH NEXT WEEK AS A SERIES
OF SHORTWAVES TRACK OVER SOUTHEAST MICHIGAN. MODEL AGREEMENT IS
STILL QUITE LOW AND HAVE THEREFORE ONLY PUT IN LOW CHANCE POPS INTO
THE FORECAST THROUGH WEDNESDAY. TIMING AND COVERAGE OF THE RAIN WILL
BE REFINED AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES.
TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID TO UPPER 60S THROUGH WEDNESDAY.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THUNDERSTORM CHANCES WILL
PERSIST MAINLY FOR CENTRAL LAKE HURON AND POINTS SOUTH THROUGH THIS
EVENING. THERE IS THEN A CHANCE FOR THUNDERSTORMS FOR ALL MARINE
AREAS LATE THURSDAY NIGHT INTO EARLY FRIDAY...AND SEVERE WEATHER IS
NOT OUT OF THE QUESTION DURING THIS TIME. MODERATE SOUTHWESTERLY
FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT A
MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

UPDATE.......BT
AVIATION.....BT
SHORT TERM...MM
LONG TERM....JVC/RK
MARINE.......JVC


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











000
FXUS63 KDTX 202317
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
717 PM EDT WED AUG 20 2014

.AVIATION...

//DISCUSSION...

EARLY EVENING OBSERVATIONS INDICATE SHOWERS AND THUNDERSTORMS
DIMINISHING RAPIDLY WITH THE LOSS OF DAYTIME HEATING AND A
SUBSTANTIAL LOSS OF CLOUD COVER AS WELL. THIS WILL LEAVE VFR
CONDITIONS IN PLACE AT ALL TERMINALS THROUGH MIDNIGHT BEFORE OPEN
SKY WITH LIGHT AND VARIABLE WIND PROMOTES ANOTHER ROUND OF FOG.
EXPECT IFR CONDITIONS TO RESULT IN SIMILAR RESTRICTION TO LAST
NIGHT BUT WITH LESS STRATUS AND MORE OF A FOG COMPONENT. A TYPICAL
TREND OF MORNING IMPROVEMENT IN VISIBILITY IS EXPECTED ALONG WITH
ANOTHER ROUND OF SHOWERS AND STORMS MAINLY DURING LATE THURSDAY
AFTERNOON INTO THE EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AS FOG LIFTS THURSDAY
MORNING.

* LOW CONFIDENCE IN 200 FT CEILING AND 1/2 SM VISIBILITY.

&&

.PREV DISCUSSION...ISSUED 323 PM EDT WED AUG 20 2014

SHORT TERM...TONIGHT

STACKED LOW PRESSURE CONTINUES TO CHURN OVER NORTHERN MICHIGAN THIS
EVENING. THE UPPER LOW WILL PIVOT SOME THIS EVENING TO CREATE A
NEGATIVE TILT WITHIN THE BROAD 500MB TROUGH PATTERN TONIGHT. AS THE
FEATURE TILTS...AN AREA OF SURFACE CONVERGENCE WILL HELP SPARK
CONTINUED SHOWERS WITH ISOLATED THUNDERSTORMS. WHILE THERE IS A
FORECASTED MAXIMUM OF 25KT H85 WINDS OVER SRN MI THIS EVENING...THE
OVERALL FLOW IS VERY WEAK. THIS WILL LEAD TO SLOW MOVING SINGLE
CELLS. BOTH MOISTURE CONTENT AND INSTABILITY ARE MODEST TODAY /1.5
INCH PWAT AND 1500 J/KG CAPE/ BUT ARE AMPLE TO PRODUCE SOME
CONVECTION WITH LITTLE POTENTIAL FOR DAMAGING WINDS OR HAIL. 0-6 KM
BULK SHEAR OF 25 KT IS UNIDIRECTIONAL...LEADING TO LITTLE RISK FOR
ROTATION TODAY.

THE DIURNALLY DRIVEN CONVECTION WILL COME TO AN END AFTER 01Z THIS
EVENING. JUST A FEW ISOLATED SHOWERS WILL BE POSSIBLE THEREAFTER
FROM THE SAGINAW VALLEY TO EASTERN THUMB REGION...CLOSER TO THE
CENTER OF THE SURFACE LOW. MINS TONIGHT RANGE FROM THE UPPER 50 TO
LOW 60S. THERE IS POTENTIAL FOR AM FOG AGAIN TOMORROW...WHICH MAY BE
MITIGATED BY CIRRUS BLOWOFF FROM UPSTREAM WARM FRONTAL SYSTEM. AREAS
NORTH OF I-69 HOLD THE BETTER CHANCE FOR FOG DEVELOPMENT WITH LIGHT
WINDS AND INCREASED MOISTURE CONTENT.

LONG TERM...

LONGWAVE FEEDBACK ASSOCIATED WITH STRONG JET ENERGY DIGGING INTO THE
PAC NW AND INTERMOUNTAIN WEST WILL FORCE THE SUBTROPICAL RIDGE
ANCHORED OVER THE SOUTHERN UNITED STATES TO UNDERGO NOTEWORTHY
AMPLIFICATION HEADING INTO THE WEEKEND. DURING THIS TIME, SOUTHEAST
MICHIGAN WILL RESIDE ON THE EDGE OF THE INSTABILITY GRADIENT WITH NO
APPRECIABLE UPPER FORCING TO SPEAK OF. AS A RESULT, THE FORECAST
FEATURES SEVERAL PERIODS CONSISTING MAINLY OF CHANCE POPS TO ACCOUNT
FOR THE RATHER NEBULOUS PERIOD OF CONVECTIVE POTENTIAL.

DURING THE NEXT 48 HOURS, THE HIGHEST PROBABILITY SCENARIO WILL BE
FOR SOUTHEAST MICHIGAN TO FEAST UPON THE LEFTOVERS OF UPSTREAM
REMNANTS. HIGH RES SOLUTIONS SUGGEST THAT THIS WILL BE THE CASE ON
THURSDAY AS HIGH PLAINS REMNANTS PROPAGATE INTO THE OHIO VALLEY,
EXPERIENCING A DIURNAL FLARE-UP DURING THE DAY WHICH IS MOST LIKELY
TO OCCUR TO OUR SOUTH...OR AT LEAST SOUTH OF THE METRO AREA...GIVEN
THE PROGGED LOCATION OF HIGHER INSTABILITY. HOWEVER...DIURNAL
HEATING INVOF NORTHWARD ADVANCING WARM FRONT WILL PRESENT THE
OPPORTUNITY FOR ISOLATED TO PERHAPS SCATTERED THUNDERSTORM DEVELOP
DURING THE DAY. ADEQUATE SHEAR AROUND 35 KNOTS WILL BE SUFFICIENT TO
SUPPORT ORGANIZED UPDRAFTS DEPENDING ON CLOUD COVER/INSTABILITY, SO
A MARGINAL RISK FOR SEVERE WEATHER DOES EXIST.

A SIMILAR SITUATION WILL BE PRESENT THURSDAY NIGHT INTO FRIDAY
MORNING, EXCEPT WITH THE FAVORABLE THERMODYNAMIC ENVIRONMENT
CREEPING CLOSER. THE GENESIS REGION FOR ANY THURSDAY NIGHT ACTIVITY
WILL LIKELY BE INVOF THE APEX OF THE RIDGE/EDGE OF THE CAP SOMEWHERE
IN THE UPPER MS RIVER VALLEY PER PATTERN RECOGNITION/HIGH-RES MODEL
SIGNALS. MESOSCALE DETAILS THAT WILL NOT BECOME CLEAR UNTIL THURSDAY
OR THURSDAY NIGHT ENTER THE NEAR TERM WILL BE CRITICAL. THE
POTENTIAL FOR COLD POOL DEVELOPMENT AND MAINTENANCE WILL NEED TO BE
MONITORED AS IT WILL DETERMINE THE POTENTIAL FOR UPSCALE GROWTH AS
THIS ACTIVITY DIVES INTO THE LOWER PENINSULA, WHERE THE
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE - BUT NOT EXCEPTIONAL -
LATE THURSDAY NIGHT.

HIGH TEMPS WILL CREEP UPWARD THROUGH MUCH OF THE LONG TERM PERIOD AS
THE AFOREMENTIONED RIDGE AMPLIFIES AND H85 TEMPERATURES INCREASE
INTO THE UPPER TEENS BY FRIDAY...AND THEN FURTHER HEADING INTO THE
WEEKEND. NO ARGUMENTS WITH THE GUIDANCE WHICH SUGGESTS DAYTIME HIGHS
HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE UPPER 60S.

RAIN CHANCES WILL LIKELY STICK AROUND THROUGH NEXT WEEK AS A SERIES
OF SHORTWAVES TRACK OVER SOUTHEAST MICHIGAN. MODEL AGREEMENT IS
STILL QUITE LOW AND HAVE THEREFORE ONLY PUT IN LOW CHANCE POPS INTO
THE FORECAST THROUGH WEDNESDAY. TIMING AND COVERAGE OF THE RAIN WILL
BE REFINED AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES.
TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID TO UPPER 60S THROUGH WEDNESDAY.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THUNDERSTORM CHANCES WILL
PERSIST MAINLY FOR CENTRAL LAKE HURON AND POINTS SOUTH THROUGH THIS
EVENING. THERE IS THEN A CHANCE FOR THUNDERSTORMS FOR ALL MARINE
AREAS LATE THURSDAY NIGHT INTO EARLY FRIDAY...AND SEVERE WEATHER IS
NOT OUT OF THE QUESTION DURING THIS TIME. MODERATE SOUTHWESTERLY
FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT A
MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

AVIATION.....BT
SHORT TERM...MM
LONG TERM....JVC/RK
MARINE.......JVC


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









000
FXUS63 KDTX 202317
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
717 PM EDT WED AUG 20 2014

.AVIATION...

//DISCUSSION...

EARLY EVENING OBSERVATIONS INDICATE SHOWERS AND THUNDERSTORMS
DIMINISHING RAPIDLY WITH THE LOSS OF DAYTIME HEATING AND A
SUBSTANTIAL LOSS OF CLOUD COVER AS WELL. THIS WILL LEAVE VFR
CONDITIONS IN PLACE AT ALL TERMINALS THROUGH MIDNIGHT BEFORE OPEN
SKY WITH LIGHT AND VARIABLE WIND PROMOTES ANOTHER ROUND OF FOG.
EXPECT IFR CONDITIONS TO RESULT IN SIMILAR RESTRICTION TO LAST
NIGHT BUT WITH LESS STRATUS AND MORE OF A FOG COMPONENT. A TYPICAL
TREND OF MORNING IMPROVEMENT IN VISIBILITY IS EXPECTED ALONG WITH
ANOTHER ROUND OF SHOWERS AND STORMS MAINLY DURING LATE THURSDAY
AFTERNOON INTO THE EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AS FOG LIFTS THURSDAY
MORNING.

* LOW CONFIDENCE IN 200 FT CEILING AND 1/2 SM VISIBILITY.

&&

.PREV DISCUSSION...ISSUED 323 PM EDT WED AUG 20 2014

SHORT TERM...TONIGHT

STACKED LOW PRESSURE CONTINUES TO CHURN OVER NORTHERN MICHIGAN THIS
EVENING. THE UPPER LOW WILL PIVOT SOME THIS EVENING TO CREATE A
NEGATIVE TILT WITHIN THE BROAD 500MB TROUGH PATTERN TONIGHT. AS THE
FEATURE TILTS...AN AREA OF SURFACE CONVERGENCE WILL HELP SPARK
CONTINUED SHOWERS WITH ISOLATED THUNDERSTORMS. WHILE THERE IS A
FORECASTED MAXIMUM OF 25KT H85 WINDS OVER SRN MI THIS EVENING...THE
OVERALL FLOW IS VERY WEAK. THIS WILL LEAD TO SLOW MOVING SINGLE
CELLS. BOTH MOISTURE CONTENT AND INSTABILITY ARE MODEST TODAY /1.5
INCH PWAT AND 1500 J/KG CAPE/ BUT ARE AMPLE TO PRODUCE SOME
CONVECTION WITH LITTLE POTENTIAL FOR DAMAGING WINDS OR HAIL. 0-6 KM
BULK SHEAR OF 25 KT IS UNIDIRECTIONAL...LEADING TO LITTLE RISK FOR
ROTATION TODAY.

THE DIURNALLY DRIVEN CONVECTION WILL COME TO AN END AFTER 01Z THIS
EVENING. JUST A FEW ISOLATED SHOWERS WILL BE POSSIBLE THEREAFTER
FROM THE SAGINAW VALLEY TO EASTERN THUMB REGION...CLOSER TO THE
CENTER OF THE SURFACE LOW. MINS TONIGHT RANGE FROM THE UPPER 50 TO
LOW 60S. THERE IS POTENTIAL FOR AM FOG AGAIN TOMORROW...WHICH MAY BE
MITIGATED BY CIRRUS BLOWOFF FROM UPSTREAM WARM FRONTAL SYSTEM. AREAS
NORTH OF I-69 HOLD THE BETTER CHANCE FOR FOG DEVELOPMENT WITH LIGHT
WINDS AND INCREASED MOISTURE CONTENT.

LONG TERM...

LONGWAVE FEEDBACK ASSOCIATED WITH STRONG JET ENERGY DIGGING INTO THE
PAC NW AND INTERMOUNTAIN WEST WILL FORCE THE SUBTROPICAL RIDGE
ANCHORED OVER THE SOUTHERN UNITED STATES TO UNDERGO NOTEWORTHY
AMPLIFICATION HEADING INTO THE WEEKEND. DURING THIS TIME, SOUTHEAST
MICHIGAN WILL RESIDE ON THE EDGE OF THE INSTABILITY GRADIENT WITH NO
APPRECIABLE UPPER FORCING TO SPEAK OF. AS A RESULT, THE FORECAST
FEATURES SEVERAL PERIODS CONSISTING MAINLY OF CHANCE POPS TO ACCOUNT
FOR THE RATHER NEBULOUS PERIOD OF CONVECTIVE POTENTIAL.

DURING THE NEXT 48 HOURS, THE HIGHEST PROBABILITY SCENARIO WILL BE
FOR SOUTHEAST MICHIGAN TO FEAST UPON THE LEFTOVERS OF UPSTREAM
REMNANTS. HIGH RES SOLUTIONS SUGGEST THAT THIS WILL BE THE CASE ON
THURSDAY AS HIGH PLAINS REMNANTS PROPAGATE INTO THE OHIO VALLEY,
EXPERIENCING A DIURNAL FLARE-UP DURING THE DAY WHICH IS MOST LIKELY
TO OCCUR TO OUR SOUTH...OR AT LEAST SOUTH OF THE METRO AREA...GIVEN
THE PROGGED LOCATION OF HIGHER INSTABILITY. HOWEVER...DIURNAL
HEATING INVOF NORTHWARD ADVANCING WARM FRONT WILL PRESENT THE
OPPORTUNITY FOR ISOLATED TO PERHAPS SCATTERED THUNDERSTORM DEVELOP
DURING THE DAY. ADEQUATE SHEAR AROUND 35 KNOTS WILL BE SUFFICIENT TO
SUPPORT ORGANIZED UPDRAFTS DEPENDING ON CLOUD COVER/INSTABILITY, SO
A MARGINAL RISK FOR SEVERE WEATHER DOES EXIST.

A SIMILAR SITUATION WILL BE PRESENT THURSDAY NIGHT INTO FRIDAY
MORNING, EXCEPT WITH THE FAVORABLE THERMODYNAMIC ENVIRONMENT
CREEPING CLOSER. THE GENESIS REGION FOR ANY THURSDAY NIGHT ACTIVITY
WILL LIKELY BE INVOF THE APEX OF THE RIDGE/EDGE OF THE CAP SOMEWHERE
IN THE UPPER MS RIVER VALLEY PER PATTERN RECOGNITION/HIGH-RES MODEL
SIGNALS. MESOSCALE DETAILS THAT WILL NOT BECOME CLEAR UNTIL THURSDAY
OR THURSDAY NIGHT ENTER THE NEAR TERM WILL BE CRITICAL. THE
POTENTIAL FOR COLD POOL DEVELOPMENT AND MAINTENANCE WILL NEED TO BE
MONITORED AS IT WILL DETERMINE THE POTENTIAL FOR UPSCALE GROWTH AS
THIS ACTIVITY DIVES INTO THE LOWER PENINSULA, WHERE THE
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE - BUT NOT EXCEPTIONAL -
LATE THURSDAY NIGHT.

HIGH TEMPS WILL CREEP UPWARD THROUGH MUCH OF THE LONG TERM PERIOD AS
THE AFOREMENTIONED RIDGE AMPLIFIES AND H85 TEMPERATURES INCREASE
INTO THE UPPER TEENS BY FRIDAY...AND THEN FURTHER HEADING INTO THE
WEEKEND. NO ARGUMENTS WITH THE GUIDANCE WHICH SUGGESTS DAYTIME HIGHS
HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE UPPER 60S.

RAIN CHANCES WILL LIKELY STICK AROUND THROUGH NEXT WEEK AS A SERIES
OF SHORTWAVES TRACK OVER SOUTHEAST MICHIGAN. MODEL AGREEMENT IS
STILL QUITE LOW AND HAVE THEREFORE ONLY PUT IN LOW CHANCE POPS INTO
THE FORECAST THROUGH WEDNESDAY. TIMING AND COVERAGE OF THE RAIN WILL
BE REFINED AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES.
TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID TO UPPER 60S THROUGH WEDNESDAY.

MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THUNDERSTORM CHANCES WILL
PERSIST MAINLY FOR CENTRAL LAKE HURON AND POINTS SOUTH THROUGH THIS
EVENING. THERE IS THEN A CHANCE FOR THUNDERSTORMS FOR ALL MARINE
AREAS LATE THURSDAY NIGHT INTO EARLY FRIDAY...AND SEVERE WEATHER IS
NOT OUT OF THE QUESTION DURING THIS TIME. MODERATE SOUTHWESTERLY
FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT A
MINIMUM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

AVIATION.....BT
SHORT TERM...MM
LONG TERM....JVC/RK
MARINE.......JVC


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










000
FXUS63 KDTX 201923
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
323 PM EDT WED AUG 20 2014

.SHORT TERM...TONIGHT

STACKED LOW PRESSURE CONTINUES TO CHURN OVER NORTHERN MICHIGAN THIS
EVENING. THE UPPER LOW WILL PIVOT SOME THIS EVENING TO CREATE A
NEGATIVE TILT WITHIN THE BROAD 500MB TROUGH PATTERN TONIGHT. AS THE
FEATURE TILTS...AN AREA OF SURFACE CONVERGENCE WILL HELP SPARK
CONTINUED SHOWERS WITH ISOLATED THUNDERSTORMS. WHILE THERE IS A
FORECASTED MAXIMUM OF 25KT H85 WINDS OVER SRN MI THIS EVENING...THE
OVERALL FLOW IS VERY WEAK. THIS WILL LEAD TO SLOW MOVING SINGLE
CELLS. BOTH MOISTURE CONTENT AND INSTABILITY ARE MODEST TODAY /1.5
INCH PWAT AND 1500 J/KG CAPE/ BUT ARE AMPLE TO PRODUCE SOME
CONVECTION WITH LITTLE POTENTIAL FOR DAMAGING WINDS OR HAIL. 0-6 KM
BULK SHEAR OF 25 KT IS UNIDIRECTIONAL...LEADING TO LITTLE RISK FOR
ROTATION TODAY.

THE DIURNALLY DRIVEN CONVECTION WILL COME TO AN END AFTER 01Z THIS
EVENING. JUST A FEW ISOLATED SHOWERS WILL BE POSSIBLE THEREAFTER
FROM THE SAGINAW VALLEY TO EASTERN THUMB REGION...CLOSER TO THE
CENTER OF THE SURFACE LOW. MINS TONIGHT RANGE FROM THE UPPER 50 TO
LOW 60S. THERE IS POTENTIAL FOR AM FOG AGAIN TOMORROW...WHICH MAY BE
MITIGATED BY CIRRUS BLOWOFF FROM UPSTREAM WARM FRONTAL SYSTEM. AREAS
NORTH OF I-69 HOLD THE BETTER CHANCE FOR FOG DEVELOPMENT WITH LIGHT
WINDS AND INCREASED MOISTURE CONTENT.

&&

.LONG TERM...

LONGWAVE FEEDBACK ASSOCIATED WITH STRONG JET ENERGY DIGGING INTO THE
PAC NW AND INTERMOUNTAIN WEST WILL FORCE THE SUBTROPICAL RIDGE
ANCHORED OVER THE SOUTHERN UNITED STATES TO UNDERGO NOTEWORTHY
AMPLIFICATION HEADING INTO THE WEEKEND. DURING THIS TIME, SOUTHEAST
MICHIGAN WILL RESIDE ON THE EDGE OF THE INSTABILITY GRADIENT WITH NO
APPRECIABLE UPPER FORCING TO SPEAK OF. AS A RESULT, THE FORECAST
FEATURES SEVERAL PERIODS CONSISTING MAINLY OF CHANCE POPS TO ACCOUNT
FOR THE RATHER NEBULOUS PERIOD OF CONVECTIVE POTENTIAL.

DURING THE NEXT 48 HOURS, THE HIGHEST PROBABILITY SCENARIO WILL BE
FOR SOUTHEAST MICHIGAN TO FEAST UPON THE LEFTOVERS OF UPSTREAM
REMNANTS. HIGH RES SOLUTIONS SUGGEST THAT THIS WILL BE THE CASE ON
THURSDAY AS HIGH PLAINS REMNANTS PROPAGATE INTO THE OHIO VALLEY,
EXPERIENCING A DIURNAL FLARE-UP DURING THE DAY WHICH IS MOST LIKELY
TO OCCUR TO OUR SOUTH...OR AT LEAST SOUTH OF THE METRO AREA...GIVEN
THE PROGGED LOCATION OF HIGHER INSTABILITY. HOWEVER...DIURNAL
HEATING INVOF NORTHWARD ADVANCING WARM FRONT WILL PRESENT THE
OPPORTUNITY FOR ISOLATED TO PERHAPS SCATTERED THUNDERSTORM DEVELOP
DURING THE DAY. ADEQUATE SHEAR AROUND 35 KNOTS WILL BE SUFFICIENT TO
SUPPORT ORGANIZED UPDRAFTS DEPENDING ON CLOUD COVER/INSTABILITY, SO
A MARGINAL RISK FOR SEVERE WEATHER DOES EXIST.

A SIMILAR SITUATION WILL BE PRESENT THURSDAY NIGHT INTO FRIDAY
MORNING, EXCEPT WITH THE FAVORABLE THERMODYNAMIC ENVIRONMENT
CREEPING CLOSER. THE GENESIS REGION FOR ANY THURSDAY NIGHT ACTIVITY
WILL LIKELY BE INVOF THE APEX OF THE RIDGE/EDGE OF THE CAP SOMEWHERE
IN THE UPPER MS RIVER VALLEY PER PATTERN RECOGNITION/HIGH-RES MODEL
SIGNALS. MESOSCALE DETAILS THAT WILL NOT BECOME CLEAR UNTIL THURSDAY
OR THURSDAY NIGHT ENTER THE NEAR TERM WILL BE CRITICAL. THE
POTENTIAL FOR COLD POOL DEVELOPMENT AND MAINTENANCE WILL NEED TO BE
MONITORED AS IT WILL DETERMINE THE POTENTIAL FOR UPSCALE GROWTH AS
THIS ACTIVITY DIVES INTO THE LOWER PENINSULA, WHERE THE
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE - BUT NOT EXCEPTIONAL -
LATE THURSDAY NIGHT.

HIGH TEMPS WILL CREEP UPWARD THROUGH MUCH OF THE LONG TERM PERIOD AS
THE AFOREMENTIONED RIDGE AMPLIFIES AND H85 TEMPERATURES INCREASE
INTO THE UPPER TEENS BY FRIDAY...AND THEN FURTHER HEADING INTO THE
WEEKEND. NO ARGUMENTS WITH THE GUIDANCE WHICH SUGGESTS DAYTIME HIGHS
HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE UPPER 60S.

RAIN CHANCES WILL LIKELY STICK AROUND THROUGH NEXT WEEK AS A SERIES
OF SHORTWAVES TRACK OVER SOUTHEAST MICHIGAN. MODEL AGREEMENT IS
STILL QUITE LOW AND HAVE THEREFORE ONLY PUT IN LOW CHANCE POPS INTO
THE FORECAST THROUGH WEDNESDAY. TIMING AND COVERAGE OF THE RAIN WILL
BE REFINED AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES.
TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID TO UPPER 60S THROUGH WEDNESDAY.

&&

.MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THUNDERSTORM CHANCES WILL
PERSIST MAINLY FOR CENTRAL LAKE HURON AND POINTS SOUTH THROUGH THIS
EVENING. THERE IS THEN A CHANCE FOR THUNDERSTORMS FOR ALL MARINE
AREAS LATE THURSDAY NIGHT INTO EARLY FRIDAY...AND SEVERE WEATHER IS
NOT OUT OF THE QUESTION DURING THIS TIME. MODERATE SOUTHWESTERLY
FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT A
MINIMUM.

&&

.AVIATION...ISSUED 101 PM EDT WED AUG 20 2014

//DISCUSSION...

IFR STRATUS HAS MOSTLY LIFTED THIS AFTERNOON TO MVFR LEVELS. THIS
TREND WILL CONTINUE FOR A FEW HOURS INTO THIS TAF PERIOD. VISIBLE
SATELLITE SHOWS MANY AREAS TO THE WEST HAVE CLEARED THE STRATUS AND
DEVELOPED MVFR CUMULUS CLOUDS. BASES SHOULD LIFT ABOVE 3000 FEET
WITH TIME INTO THIS EVENING...BUT THERE WILL ALSO BE A CHANCE FOR
SHOWERS AND ISOLATED TSTORMS TO BRIEFLY LOWER VSBYS. HAVE TIMED OUT
BEST CHANCES FOR PRECIP IN THE TAFS...GENERALLY 18-01Z. FLOW IS
RATHER WEAK...SO STORM MOTION WILL BE SLOW /WEST TO EAST AT 15KT/.
PATCHY FOG SHOULD DEVELOP AGAIN TONIGHT UNDER LIGHT FLOW AND HIGH RH.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING BELOW 5000 FEET THIS AFTERNOON.

* LOW CONFIDENCE IN THUNDERSTORMS OCCURRING.

&&

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

&&

$$

SHORT TERM...MM
LONG TERM....JVC/RK
MARINE.......JVC
AVIATION.....MM


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







000
FXUS63 KDTX 201923
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
323 PM EDT WED AUG 20 2014

.SHORT TERM...TONIGHT

STACKED LOW PRESSURE CONTINUES TO CHURN OVER NORTHERN MICHIGAN THIS
EVENING. THE UPPER LOW WILL PIVOT SOME THIS EVENING TO CREATE A
NEGATIVE TILT WITHIN THE BROAD 500MB TROUGH PATTERN TONIGHT. AS THE
FEATURE TILTS...AN AREA OF SURFACE CONVERGENCE WILL HELP SPARK
CONTINUED SHOWERS WITH ISOLATED THUNDERSTORMS. WHILE THERE IS A
FORECASTED MAXIMUM OF 25KT H85 WINDS OVER SRN MI THIS EVENING...THE
OVERALL FLOW IS VERY WEAK. THIS WILL LEAD TO SLOW MOVING SINGLE
CELLS. BOTH MOISTURE CONTENT AND INSTABILITY ARE MODEST TODAY /1.5
INCH PWAT AND 1500 J/KG CAPE/ BUT ARE AMPLE TO PRODUCE SOME
CONVECTION WITH LITTLE POTENTIAL FOR DAMAGING WINDS OR HAIL. 0-6 KM
BULK SHEAR OF 25 KT IS UNIDIRECTIONAL...LEADING TO LITTLE RISK FOR
ROTATION TODAY.

THE DIURNALLY DRIVEN CONVECTION WILL COME TO AN END AFTER 01Z THIS
EVENING. JUST A FEW ISOLATED SHOWERS WILL BE POSSIBLE THEREAFTER
FROM THE SAGINAW VALLEY TO EASTERN THUMB REGION...CLOSER TO THE
CENTER OF THE SURFACE LOW. MINS TONIGHT RANGE FROM THE UPPER 50 TO
LOW 60S. THERE IS POTENTIAL FOR AM FOG AGAIN TOMORROW...WHICH MAY BE
MITIGATED BY CIRRUS BLOWOFF FROM UPSTREAM WARM FRONTAL SYSTEM. AREAS
NORTH OF I-69 HOLD THE BETTER CHANCE FOR FOG DEVELOPMENT WITH LIGHT
WINDS AND INCREASED MOISTURE CONTENT.

&&

.LONG TERM...

LONGWAVE FEEDBACK ASSOCIATED WITH STRONG JET ENERGY DIGGING INTO THE
PAC NW AND INTERMOUNTAIN WEST WILL FORCE THE SUBTROPICAL RIDGE
ANCHORED OVER THE SOUTHERN UNITED STATES TO UNDERGO NOTEWORTHY
AMPLIFICATION HEADING INTO THE WEEKEND. DURING THIS TIME, SOUTHEAST
MICHIGAN WILL RESIDE ON THE EDGE OF THE INSTABILITY GRADIENT WITH NO
APPRECIABLE UPPER FORCING TO SPEAK OF. AS A RESULT, THE FORECAST
FEATURES SEVERAL PERIODS CONSISTING MAINLY OF CHANCE POPS TO ACCOUNT
FOR THE RATHER NEBULOUS PERIOD OF CONVECTIVE POTENTIAL.

DURING THE NEXT 48 HOURS, THE HIGHEST PROBABILITY SCENARIO WILL BE
FOR SOUTHEAST MICHIGAN TO FEAST UPON THE LEFTOVERS OF UPSTREAM
REMNANTS. HIGH RES SOLUTIONS SUGGEST THAT THIS WILL BE THE CASE ON
THURSDAY AS HIGH PLAINS REMNANTS PROPAGATE INTO THE OHIO VALLEY,
EXPERIENCING A DIURNAL FLARE-UP DURING THE DAY WHICH IS MOST LIKELY
TO OCCUR TO OUR SOUTH...OR AT LEAST SOUTH OF THE METRO AREA...GIVEN
THE PROGGED LOCATION OF HIGHER INSTABILITY. HOWEVER...DIURNAL
HEATING INVOF NORTHWARD ADVANCING WARM FRONT WILL PRESENT THE
OPPORTUNITY FOR ISOLATED TO PERHAPS SCATTERED THUNDERSTORM DEVELOP
DURING THE DAY. ADEQUATE SHEAR AROUND 35 KNOTS WILL BE SUFFICIENT TO
SUPPORT ORGANIZED UPDRAFTS DEPENDING ON CLOUD COVER/INSTABILITY, SO
A MARGINAL RISK FOR SEVERE WEATHER DOES EXIST.

A SIMILAR SITUATION WILL BE PRESENT THURSDAY NIGHT INTO FRIDAY
MORNING, EXCEPT WITH THE FAVORABLE THERMODYNAMIC ENVIRONMENT
CREEPING CLOSER. THE GENESIS REGION FOR ANY THURSDAY NIGHT ACTIVITY
WILL LIKELY BE INVOF THE APEX OF THE RIDGE/EDGE OF THE CAP SOMEWHERE
IN THE UPPER MS RIVER VALLEY PER PATTERN RECOGNITION/HIGH-RES MODEL
SIGNALS. MESOSCALE DETAILS THAT WILL NOT BECOME CLEAR UNTIL THURSDAY
OR THURSDAY NIGHT ENTER THE NEAR TERM WILL BE CRITICAL. THE
POTENTIAL FOR COLD POOL DEVELOPMENT AND MAINTENANCE WILL NEED TO BE
MONITORED AS IT WILL DETERMINE THE POTENTIAL FOR UPSCALE GROWTH AS
THIS ACTIVITY DIVES INTO THE LOWER PENINSULA, WHERE THE
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE - BUT NOT EXCEPTIONAL -
LATE THURSDAY NIGHT.

HIGH TEMPS WILL CREEP UPWARD THROUGH MUCH OF THE LONG TERM PERIOD AS
THE AFOREMENTIONED RIDGE AMPLIFIES AND H85 TEMPERATURES INCREASE
INTO THE UPPER TEENS BY FRIDAY...AND THEN FURTHER HEADING INTO THE
WEEKEND. NO ARGUMENTS WITH THE GUIDANCE WHICH SUGGESTS DAYTIME HIGHS
HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE UPPER 60S.

RAIN CHANCES WILL LIKELY STICK AROUND THROUGH NEXT WEEK AS A SERIES
OF SHORTWAVES TRACK OVER SOUTHEAST MICHIGAN. MODEL AGREEMENT IS
STILL QUITE LOW AND HAVE THEREFORE ONLY PUT IN LOW CHANCE POPS INTO
THE FORECAST THROUGH WEDNESDAY. TIMING AND COVERAGE OF THE RAIN WILL
BE REFINED AS MODELS GET A BETTER HANDLE ON THESE DISTURBANCES.
TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID TO UPPER 60S THROUGH WEDNESDAY.

&&

.MARINE...

A WEAK PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS ACROSS THE WATERS
THROUGH THE FIRST HALF OF THE WEEKEND. THUNDERSTORM CHANCES WILL
PERSIST MAINLY FOR CENTRAL LAKE HURON AND POINTS SOUTH THROUGH THIS
EVENING. THERE IS THEN A CHANCE FOR THUNDERSTORMS FOR ALL MARINE
AREAS LATE THURSDAY NIGHT INTO EARLY FRIDAY...AND SEVERE WEATHER IS
NOT OUT OF THE QUESTION DURING THIS TIME. MODERATE SOUTHWESTERLY
FLOW WILL DEVELOP BY SUNDAY BUT WIND GUSTS WILL REMAIN AT A
MINIMUM.

&&

.AVIATION...ISSUED 101 PM EDT WED AUG 20 2014

//DISCUSSION...

IFR STRATUS HAS MOSTLY LIFTED THIS AFTERNOON TO MVFR LEVELS. THIS
TREND WILL CONTINUE FOR A FEW HOURS INTO THIS TAF PERIOD. VISIBLE
SATELLITE SHOWS MANY AREAS TO THE WEST HAVE CLEARED THE STRATUS AND
DEVELOPED MVFR CUMULUS CLOUDS. BASES SHOULD LIFT ABOVE 3000 FEET
WITH TIME INTO THIS EVENING...BUT THERE WILL ALSO BE A CHANCE FOR
SHOWERS AND ISOLATED TSTORMS TO BRIEFLY LOWER VSBYS. HAVE TIMED OUT
BEST CHANCES FOR PRECIP IN THE TAFS...GENERALLY 18-01Z. FLOW IS
RATHER WEAK...SO STORM MOTION WILL BE SLOW /WEST TO EAST AT 15KT/.
PATCHY FOG SHOULD DEVELOP AGAIN TONIGHT UNDER LIGHT FLOW AND HIGH RH.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING BELOW 5000 FEET THIS AFTERNOON.

* LOW CONFIDENCE IN THUNDERSTORMS OCCURRING.

&&

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

&&

$$

SHORT TERM...MM
LONG TERM....JVC/RK
MARINE.......JVC
AVIATION.....MM


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








000
FXUS63 KDTX 201701
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
101 PM EDT WED AUG 20 2014


.AVIATION...

//DISCUSSION...

IFR STRATUS HAS MOSTLY LIFTED THIS AFTERNOON TO MVFR LEVELS. THIS
TREND WILL CONTINUE FOR A FEW HOURS INTO THIS TAF PERIOD. VISIBLE
SATELLITE SHOWS MANY AREAS TO THE WEST HAVE CLEARED THE STRATUS AND
DEVELOPED MVFR CUMULUS CLOUDS. BASES SHOULD LIFT ABOVE 3000 FEET
WITH TIME INTO THIS EVENING...BUT THERE WILL ALSO BE A CHANCE FOR
SHOWERS AND ISOLATED TSTORMS TO BRIEFLY LOWER VSBYS. HAVE TIMED OUT
BEST CHANCES FOR PRECIP IN THE TAFS...GENERALLY 18-01Z. FLOW IS
RATHER WEAK...SO STORM MOTION WILL BE SLOW /WEST TO EAST AT 15KT/.
PATCHY FOG SHOULD DEVELOP AGAIN TONIGHT UNDER LIGHT FLOW AND HIGH RH.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING BELOW 5000 FEET THIS AFTERNOON.

* LOW CONFIDENCE IN THUNDERSTORMS OCCURRING.

&&

.PREV DISCUSSION...ISSUED 357 AM EDT WED AUG 20 2014

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE TRACKED EAST AS A COLD FRONT HAS
SWEPT THROUGH THE CENTRAL GREAT LAKES. HOWEVER THIS COLD FRONT WILL
NOT BRING MUCH RELIEF WITH REGARDS TO MOISTURE AS DEW POINTS ARE
STILL IN THE LOWER TO MIDDLE 60S. THE LACK OF DRY AIR BEHIND THE
FRONT AND FAIRLY CALM WINDS BRINGS WITH IT THE POTENTIAL FOR FOG
ACROSS THE AREA. LINGERING CLOUDS SHOULD DELAY THE ONSET OF FOG
FORMATION...WITH AREAS TO THE EAST PROBABLY NOT GOING DOWN UNTIL
AROUND SUNRISE. ALTHOUGH THERE ARE EXPECTED TO BE AREAS OF DENSE FOG
THIS MORNING...IT IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO WARRANT
A DENSE FOG ADVISORY AT THIS POINT. HOWEVER IF VISIBILITIES DROP
SIGNIFICANTLY WILL ISSUE THE APPROPRIATE HEADLINES AS NEEDED. THE
LINGERING MOISTURE MAY STILL SPARK OFF SOME LIGHT SHOWER ACTIVITY
EARLY THIS MORNING AS A RIBBON OF HIGH LOW LEVEL THETA-E AIR REMAINS
OVER SOUTHEAST MICHIGAN.

DAYTIME HEATING WILL ONCE AGAIN CAUSE AN UNSTABLE ATMOSPHERE AS IT
COMBINES WITH A STILL MOIST BOUNDARY LAYER TO PRODUCE MUCAPES OF
1500 TO 2000 J/KG. THIS SHOULD ONCE AGAIN SPARK OFF THUNDERSTORMS
ACROSS THE AREA AS THE MID LEVEL LOW PRESSURE SYSTEM TRACKS THROUGH
THE SOO TODAY. HOWEVER UNLIKE YESTERDAY 0-6KM BULK SHEAR VALUES WILL
BE MUCH WEAKER AT AROUND 20 KNOTS...MAKING THE THREAT FOR SEVERE
WEATHER MUCH LOWER. STORMS TODAY MAY PRODUCE WIND GUSTS UP OF 40 TO
50 MPH WITH HAIL AROUND ONE HALF OF AN INCH UP TO DIME SIZE WITH THE
STRONGEST STORMS.

ALTHOUGH THE MID LEVEL LOW WILL REMAIN OVER LAKE HURON
OVERNIGHT...RAIN CHANCES WILL DROP OFF WITH THE LOSS OF DAYTIME
HEATING. RAIN SHOULD BE CONFINED TO THE AREAS NEAR THE LOW WHICH
WILL BE THE THUMB REGION...WITH CHANCES CREEPING IN ACROSS THE
EXTREME SOUTHERN CWA LATE TONIGHT AS A QUICK MOVING SHORTWAVE TRACKS
THROUGH THE SOUTHERN GREAT LAKES.

LONG TERM...

A LONGWAVE AMPLIFIED RIDGE AXIS WILL BUILD AGGRESSIVELY INTO
NORTHEASTERN NORTH AMERICA DURING THE NEXT 48 HOURS. IT GOES WITHOUT
SAYING...BUT AN EXTREMELY ATYPICAL EVENT FOR THIS SUMMER. WHAT THIS
WILL DO IS ESSENTIALLY THROW A CURVE BALL TO THE LOCAL WEATHER
PATTERN...LIKELY BRINGING IN THE LARGEST RUN OF SUMMER WARMTH THIS
REGION HAS SEEN ALL SEASON LONG. BEFORE THIS CAN REALLY BECOME
ESTABLISHED DURING THE LATTER HALF OF THE WEEKEND...SOUTHEASTERN
MICHIGAN WILL HAVE TO CONTEND WITH AN INTERNAL RIDGE STRUCTURE AND
SECONDARY JET CORE. IT IS THIS SECONDARY JET OVERHEAD THAT WILL
DIRECT SHORTWAVE ENERGY AND POTENTIAL RIDGE RIDER TYPE MCS INTO THE
AREA LIKELY ANYTIME THROUGH SATURDAY. AN ACTIVE PERIOD IS IN STORE
THROUGH THE END OF THE WEEK.

THURSDAY...A LOWER GEOPOTENTIAL HEIGHT ANOMALY WILL BUILD OFF OF
LAKE HURON AND INTO THE NORTHEASTERN UNITED STATES DURING THE DAY ON
FRIDAY. IT IS THE COMBINATION OF THIS ACTION AND AN UPPER LEVEL JET
CORE CRESTING THE RIDGE AXIS OVER THE PLAINS/NORTHERN MISSISSIPPI
RIVER VALLEY THAT THAT WILL FREEZE THE HEIGHT PATTERN OVER LOWER
MICHIGAN. QUITE THE GRADIENT IN TEMPERATURES IS EXPECTED WITH A
STATIONARY FRONTAL BOUNDARY DRAPED FROM PORTIONS OF OHIO
NORTHWESTWARD TO CENTRAL LOWER MICHIGAN NW TO PORTIONS OF THE U.P.
THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH KEEPING THE HEAT
TO THE SOUTHWEST. MODELS KEEP THE BULK OF THE CWA DRY...ALTHOUGH THE
FRONTAL BOUNDARY WILL BRING THE POTETNIAL FOR SHOWERS AND
THUNDERSTORMS PARTICULALRY SOUTH AND WEST OF M 59. TEMPERATURE
SHOULD TICK ABOVE THE 80 DEGREE MARK FOR MANY AREAS.

THE AFORMENTIONED 300MB JETLET IS FORECASTED TO CREST THE RIDGE
THURSDAY EVENING AND SLIDE DIRECTLY INTO SOUTHEASTERN MICHIGAN
THURSDAY NIGHT/FRIDAY MORNING. MODELS ARE EXTREMELY NOISY...BUT
OVERALL THERE IS A VERY GOOD SIGNAL THAT AN MCS COULD BUILD ACROSS
THE NORTHERN MISSSIPPI RIVER VALLEY THURSDAY AND RELEASE TOWARDS THE
AREA THURSDAY NIGHT. ALOT OF TIME TO FIGURE THIS OUT...BUT DEGREE OF
INSTABILITY IMMEDIATELY TO THE SOUTH DUE TO STRONG LAPSE RATES ALOFT
COULD LEAD TO SEVERE WEATHER RISK FRIDAY MORNING. ONE THING TO
MONIOR IS THE MCS WILL LIKELY ORGANIZED/INTENSIFY IN AN AREA OF
STRONG LEFT EXIT REGION DYNAMICS. THE OVERALL SYSTEM IS THEN SHOWN
TO OUTRUN THE UPPER LEVEL JET SUPPORT BY DIVING TO THE SOUTH.

FRIDAY...FRIDAY IS A DIFFICULT FORECAST PERIOD. WILL LIKELY NEED TO
COMBAT SUBSIDENCE AND MIDLEVEL LATENT HEATING LEFTOVER FROM THE MCS
IMPACTING THE REGION. UPPER LEVEL JET CORE WILL MAINTAIN ENOUGH
INTEGRITY TO BRING PESKY SHORTWAVE ENERGY INTO PLAY. MODELS SUPPORT
ADVECTING HIGH THETA E INTO THE STATE ENOUGH FOR WHAT COULD END UP
TO BE A VERY HIGH CAPE SETUP.

MARINE...

A WEAK AREA OF LOW PRESSURE WILL SLIDE ACROSS LOWER MICHIGAN TODAY
BRINGING A WEAK SOUTHEASTERLY WIND TO MANY AREAS. A SECOND WEAK AREA
OF LOW PRESSURE WILL PUSH INTO THE NORTHERN GREAT LAKES ON
FRIDAY...MAINTAINING A RATHER SIZABLE SURFACE TROUGH STRUCTURE OVER
THE GREAT LAKES REGION. OUTSIDE OF CONTINUAL SHOWER AND THUNDERSTORM
CHANCES...AN EXTENDED STRETCH OF MARINE WEATHER IS ANTICIPATED.

&&

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

&&

$$

AVIATION.....MM
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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







000
FXUS63 KDTX 201701
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
101 PM EDT WED AUG 20 2014


.AVIATION...

//DISCUSSION...

IFR STRATUS HAS MOSTLY LIFTED THIS AFTERNOON TO MVFR LEVELS. THIS
TREND WILL CONTINUE FOR A FEW HOURS INTO THIS TAF PERIOD. VISIBLE
SATELLITE SHOWS MANY AREAS TO THE WEST HAVE CLEARED THE STRATUS AND
DEVELOPED MVFR CUMULUS CLOUDS. BASES SHOULD LIFT ABOVE 3000 FEET
WITH TIME INTO THIS EVENING...BUT THERE WILL ALSO BE A CHANCE FOR
SHOWERS AND ISOLATED TSTORMS TO BRIEFLY LOWER VSBYS. HAVE TIMED OUT
BEST CHANCES FOR PRECIP IN THE TAFS...GENERALLY 18-01Z. FLOW IS
RATHER WEAK...SO STORM MOTION WILL BE SLOW /WEST TO EAST AT 15KT/.
PATCHY FOG SHOULD DEVELOP AGAIN TONIGHT UNDER LIGHT FLOW AND HIGH RH.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING BELOW 5000 FEET THIS AFTERNOON.

* LOW CONFIDENCE IN THUNDERSTORMS OCCURRING.

&&

.PREV DISCUSSION...ISSUED 357 AM EDT WED AUG 20 2014

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE TRACKED EAST AS A COLD FRONT HAS
SWEPT THROUGH THE CENTRAL GREAT LAKES. HOWEVER THIS COLD FRONT WILL
NOT BRING MUCH RELIEF WITH REGARDS TO MOISTURE AS DEW POINTS ARE
STILL IN THE LOWER TO MIDDLE 60S. THE LACK OF DRY AIR BEHIND THE
FRONT AND FAIRLY CALM WINDS BRINGS WITH IT THE POTENTIAL FOR FOG
ACROSS THE AREA. LINGERING CLOUDS SHOULD DELAY THE ONSET OF FOG
FORMATION...WITH AREAS TO THE EAST PROBABLY NOT GOING DOWN UNTIL
AROUND SUNRISE. ALTHOUGH THERE ARE EXPECTED TO BE AREAS OF DENSE FOG
THIS MORNING...IT IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO WARRANT
A DENSE FOG ADVISORY AT THIS POINT. HOWEVER IF VISIBILITIES DROP
SIGNIFICANTLY WILL ISSUE THE APPROPRIATE HEADLINES AS NEEDED. THE
LINGERING MOISTURE MAY STILL SPARK OFF SOME LIGHT SHOWER ACTIVITY
EARLY THIS MORNING AS A RIBBON OF HIGH LOW LEVEL THETA-E AIR REMAINS
OVER SOUTHEAST MICHIGAN.

DAYTIME HEATING WILL ONCE AGAIN CAUSE AN UNSTABLE ATMOSPHERE AS IT
COMBINES WITH A STILL MOIST BOUNDARY LAYER TO PRODUCE MUCAPES OF
1500 TO 2000 J/KG. THIS SHOULD ONCE AGAIN SPARK OFF THUNDERSTORMS
ACROSS THE AREA AS THE MID LEVEL LOW PRESSURE SYSTEM TRACKS THROUGH
THE SOO TODAY. HOWEVER UNLIKE YESTERDAY 0-6KM BULK SHEAR VALUES WILL
BE MUCH WEAKER AT AROUND 20 KNOTS...MAKING THE THREAT FOR SEVERE
WEATHER MUCH LOWER. STORMS TODAY MAY PRODUCE WIND GUSTS UP OF 40 TO
50 MPH WITH HAIL AROUND ONE HALF OF AN INCH UP TO DIME SIZE WITH THE
STRONGEST STORMS.

ALTHOUGH THE MID LEVEL LOW WILL REMAIN OVER LAKE HURON
OVERNIGHT...RAIN CHANCES WILL DROP OFF WITH THE LOSS OF DAYTIME
HEATING. RAIN SHOULD BE CONFINED TO THE AREAS NEAR THE LOW WHICH
WILL BE THE THUMB REGION...WITH CHANCES CREEPING IN ACROSS THE
EXTREME SOUTHERN CWA LATE TONIGHT AS A QUICK MOVING SHORTWAVE TRACKS
THROUGH THE SOUTHERN GREAT LAKES.

LONG TERM...

A LONGWAVE AMPLIFIED RIDGE AXIS WILL BUILD AGGRESSIVELY INTO
NORTHEASTERN NORTH AMERICA DURING THE NEXT 48 HOURS. IT GOES WITHOUT
SAYING...BUT AN EXTREMELY ATYPICAL EVENT FOR THIS SUMMER. WHAT THIS
WILL DO IS ESSENTIALLY THROW A CURVE BALL TO THE LOCAL WEATHER
PATTERN...LIKELY BRINGING IN THE LARGEST RUN OF SUMMER WARMTH THIS
REGION HAS SEEN ALL SEASON LONG. BEFORE THIS CAN REALLY BECOME
ESTABLISHED DURING THE LATTER HALF OF THE WEEKEND...SOUTHEASTERN
MICHIGAN WILL HAVE TO CONTEND WITH AN INTERNAL RIDGE STRUCTURE AND
SECONDARY JET CORE. IT IS THIS SECONDARY JET OVERHEAD THAT WILL
DIRECT SHORTWAVE ENERGY AND POTENTIAL RIDGE RIDER TYPE MCS INTO THE
AREA LIKELY ANYTIME THROUGH SATURDAY. AN ACTIVE PERIOD IS IN STORE
THROUGH THE END OF THE WEEK.

THURSDAY...A LOWER GEOPOTENTIAL HEIGHT ANOMALY WILL BUILD OFF OF
LAKE HURON AND INTO THE NORTHEASTERN UNITED STATES DURING THE DAY ON
FRIDAY. IT IS THE COMBINATION OF THIS ACTION AND AN UPPER LEVEL JET
CORE CRESTING THE RIDGE AXIS OVER THE PLAINS/NORTHERN MISSISSIPPI
RIVER VALLEY THAT THAT WILL FREEZE THE HEIGHT PATTERN OVER LOWER
MICHIGAN. QUITE THE GRADIENT IN TEMPERATURES IS EXPECTED WITH A
STATIONARY FRONTAL BOUNDARY DRAPED FROM PORTIONS OF OHIO
NORTHWESTWARD TO CENTRAL LOWER MICHIGAN NW TO PORTIONS OF THE U.P.
THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH KEEPING THE HEAT
TO THE SOUTHWEST. MODELS KEEP THE BULK OF THE CWA DRY...ALTHOUGH THE
FRONTAL BOUNDARY WILL BRING THE POTETNIAL FOR SHOWERS AND
THUNDERSTORMS PARTICULALRY SOUTH AND WEST OF M 59. TEMPERATURE
SHOULD TICK ABOVE THE 80 DEGREE MARK FOR MANY AREAS.

THE AFORMENTIONED 300MB JETLET IS FORECASTED TO CREST THE RIDGE
THURSDAY EVENING AND SLIDE DIRECTLY INTO SOUTHEASTERN MICHIGAN
THURSDAY NIGHT/FRIDAY MORNING. MODELS ARE EXTREMELY NOISY...BUT
OVERALL THERE IS A VERY GOOD SIGNAL THAT AN MCS COULD BUILD ACROSS
THE NORTHERN MISSSIPPI RIVER VALLEY THURSDAY AND RELEASE TOWARDS THE
AREA THURSDAY NIGHT. ALOT OF TIME TO FIGURE THIS OUT...BUT DEGREE OF
INSTABILITY IMMEDIATELY TO THE SOUTH DUE TO STRONG LAPSE RATES ALOFT
COULD LEAD TO SEVERE WEATHER RISK FRIDAY MORNING. ONE THING TO
MONIOR IS THE MCS WILL LIKELY ORGANIZED/INTENSIFY IN AN AREA OF
STRONG LEFT EXIT REGION DYNAMICS. THE OVERALL SYSTEM IS THEN SHOWN
TO OUTRUN THE UPPER LEVEL JET SUPPORT BY DIVING TO THE SOUTH.

FRIDAY...FRIDAY IS A DIFFICULT FORECAST PERIOD. WILL LIKELY NEED TO
COMBAT SUBSIDENCE AND MIDLEVEL LATENT HEATING LEFTOVER FROM THE MCS
IMPACTING THE REGION. UPPER LEVEL JET CORE WILL MAINTAIN ENOUGH
INTEGRITY TO BRING PESKY SHORTWAVE ENERGY INTO PLAY. MODELS SUPPORT
ADVECTING HIGH THETA E INTO THE STATE ENOUGH FOR WHAT COULD END UP
TO BE A VERY HIGH CAPE SETUP.

MARINE...

A WEAK AREA OF LOW PRESSURE WILL SLIDE ACROSS LOWER MICHIGAN TODAY
BRINGING A WEAK SOUTHEASTERLY WIND TO MANY AREAS. A SECOND WEAK AREA
OF LOW PRESSURE WILL PUSH INTO THE NORTHERN GREAT LAKES ON
FRIDAY...MAINTAINING A RATHER SIZABLE SURFACE TROUGH STRUCTURE OVER
THE GREAT LAKES REGION. OUTSIDE OF CONTINUAL SHOWER AND THUNDERSTORM
CHANCES...AN EXTENDED STRETCH OF MARINE WEATHER IS ANTICIPATED.

&&

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

&&

$$

AVIATION.....MM
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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








000
FXUS63 KDTX 201127
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
727 AM EDT WED AUG 20 2014


.AVIATION...

//DISCUSSION...

SOME MORNING FOG WILL PLAGUE THE TAF SITES EARLY THIS MORNING...WITH
THE LOWEST CONDITIONS OF LIFR OVER MBS...WITH ONLY MVFR OVER THE
METRO AIRPORTS. THIS FOG IS EXPECTED TO LIFT LATER THIS MORNING WITH
THE ONSET OF DAYTIME HEATING. SHOWERS AND THUNDERSTORMS ARE AGAIN
EXPECTED THIS AFTERNOON AND EARLY THIS EVENING UNDERNEATH A MID
LEVEL LOW PRESSURE SYSTEM WITH INSTABILITY FROM DAYTIME HEATING.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING AOB 5000 FT THIS MORNING.

* MEDIUM CONFIDENCE IN THUNDERSTORM COVERAGE AND TIMING.

&&

.PREV DISCUSSION...ISSUED 357 AM EDT WED AUG 20 2014

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE TRACKED EAST AS A COLD FRONT HAS
SWEPT THROUGH THE CENTRAL GREAT LAKES. HOWEVER THIS COLD FRONT WILL
NOT BRING MUCH RELIEF WITH REGARDS TO MOISTURE AS DEW POINTS ARE
STILL IN THE LOWER TO MIDDLE 60S. THE LACK OF DRY AIR BEHIND THE
FRONT AND FAIRLY CALM WINDS BRINGS WITH IT THE POTENTIAL FOR FOG
ACROSS THE AREA. LINGERING CLOUDS SHOULD DELAY THE ONSET OF FOG
FORMATION...WITH AREAS TO THE EAST PROBABLY NOT GOING DOWN UNTIL
AROUND SUNRISE. ALTHOUGH THERE ARE EXPECTED TO BE AREAS OF DENSE FOG
THIS MORNING...IT IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO WARRANT
A DENSE FOG ADVISORY AT THIS POINT. HOWEVER IF VISIBILITIES DROP
SIGNIFICANTLY WILL ISSUE THE APPROPRIATE HEADLINES AS NEEDED. THE
LINGERING MOISTURE MAY STILL SPARK OFF SOME LIGHT SHOWER ACTIVITY
EARLY THIS MORNING AS A RIBBON OF HIGH LOW LEVEL THETA-E AIR REMAINS
OVER SOUTHEAST MICHIGAN.

DAYTIME HEATING WILL ONCE AGAIN CAUSE AN UNSTABLE ATMOSPHERE AS IT
COMBINES WITH A STILL MOIST BOUNDARY LAYER TO PRODUCE MUCAPES OF
1500 TO 2000 J/KG. THIS SHOULD ONCE AGAIN SPARK OFF THUNDERSTORMS
ACROSS THE AREA AS THE MID LEVEL LOW PRESSURE SYSTEM TRACKS THROUGH
THE SOO TODAY. HOWEVER UNLIKE YESTERDAY 0-6KM BULK SHEAR VALUES WILL
BE MUCH WEAKER AT AROUND 20 KNOTS...MAKING THE THREAT FOR SEVERE
WEATHER MUCH LOWER. STORMS TODAY MAY PRODUCE WIND GUSTS UP OF 40 TO
50 MPH WITH HAIL AROUND ONE HALF OF AN INCH UP TO DIME SIZE WITH THE
STRONGEST STORMS.

ALTHOUGH THE MID LEVEL LOW WILL REMAIN OVER LAKE HURON
OVERNIGHT...RAIN CHANCES WILL DROP OFF WITH THE LOSS OF DAYTIME
HEATING. RAIN SHOULD BE CONFINED TO THE AREAS NEAR THE LOW WHICH
WILL BE THE THUMB REGION...WITH CHANCES CREEPING IN ACROSS THE
EXTREME SOUTHERN CWA LATE TONIGHT AS A QUICK MOVING SHORTWAVE TRACKS
THROUGH THE SOUTHERN GREAT LAKES.

LONG TERM...

A LONGWAVE AMPLIFIED RIDGE AXIS WILL BUILD AGGRESSIVELY INTO
NORTHEASTERN NORTH AMERICA DURING THE NEXT 48 HOURS. IT GOES WITHOUT
SAYING...BUT AN EXTREMELY ATYPICAL EVENT FOR THIS SUMMER. WHAT THIS
WILL DO IS ESSENTIALLY THROW A CURVE BALL TO THE LOCAL WEATHER
PATTERN...LIKELY BRINGING IN THE LARGEST RUN OF SUMMER WARMTH THIS
REGION HAS SEEN ALL SEASON LONG. BEFORE THIS CAN REALLY BECOME
ESTABLISHED DURING THE LATTER HALF OF THE WEEKEND...SOUTHEASTERN
MICHIGAN WILL HAVE TO CONTEND WITH AN INTERNAL RIDGE STRUCTURE AND
SECONDARY JET CORE. IT IS THIS SECONDARY JET OVERHEAD THAT WILL
DIRECT SHORTWAVE ENERGY AND POTENTIAL RIDGE RIDER TYPE MCS INTO THE
AREA LIKELY ANYTIME THROUGH SATURDAY. AN ACTIVE PERIOD IS IN STORE
THROUGH THE END OF THE WEEK.

THURSDAY...A LOWER GEOPOTENTIAL HEIGHT ANOMALY WILL BUILD OFF OF
LAKE HURON AND INTO THE NORTHEASTERN UNITED STATES DURING THE DAY ON
FRIDAY. IT IS THE COMBINATION OF THIS ACTION AND AN UPPER LEVEL JET
CORE CRESTING THE RIDGE AXIS OVER THE PLAINS/NORTHERN MISSISSIPPI
RIVER VALLEY THAT THAT WILL FREEZE THE HEIGHT PATTERN OVER LOWER
MICHIGAN. QUITE THE GRADIENT IN TEMPERATURES IS EXPECTED WITH A
STATIONARY FRONTAL BOUNDARY DRAPED FROM PORTIONS OF OHIO
NORTHWESTWARD TO CENTRAL LOWER MICHIGAN NW TO PORTIONS OF THE U.P.
THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH KEEPING THE HEAT
TO THE SOUTHWEST. MODELS KEEP THE BULK OF THE CWA DRY...ALTHOUGH THE
FRONTAL BOUNDARY WILL BRING THE POTETNIAL FOR SHOWERS AND
THUNDERSTORMS PARTICULALRY SOUTH AND WEST OF M 59. TEMPERATURE
SHOULD TICK ABOVE THE 80 DEGREE MARK FOR MANY AREAS.

THE AFORMENTIONED 300MB JETLET IS FORECASTED TO CREST THE RIDGE
THURSDAY EVENING AND SLIDE DIRECTLY INTO SOUTHEASTERN MICHIGAN
THURSDAY NIGHT/FRIDAY MORNING. MODELS ARE EXTREMELY NOISY...BUT
OVERALL THERE IS A VERY GOOD SIGNAL THAT AN MCS COULD BUILD ACROSS
THE NORTHERN MISSSIPPI RIVER VALLEY THURSDAY AND RELEASE TOWARDS THE
AREA THURSDAY NIGHT. ALOT OF TIME TO FIGURE THIS OUT...BUT DEGREE OF
INSTABILITY IMMEDIATELY TO THE SOUTH DUE TO STRONG LAPSE RATES ALOFT
COULD LEAD TO SEVERE WEATHER RISK FRIDAY MORNING. ONE THING TO
MONIOR IS THE MCS WILL LIKELY ORGANIZED/INTENSIFY IN AN AREA OF
STRONG LEFT EXIT REGION DYNAMICS. THE OVERALL SYSTEM IS THEN SHOWN
TO OUTRUN THE UPPER LEVEL JET SUPPORT BY DIVING TO THE SOUTH.

FRIDAY...FRIDAY IS A DIFFICULT FORECAST PERIOD. WILL LIKELY NEED TO
COMBAT SUBSIDENCE AND MIDLEVEL LATENT HEATING LEFTOVER FROM THE MCS
IMPACTING THE REGION. UPPER LEVEL JET CORE WILL MAINTAIN ENOUGH
INTEGRITY TO BRING PESKY SHORTWAVE ENERGY INTO PLAY. MODELS SUPPORT
ADVECTING HIGH THETA E INTO THE STATE ENOUGH FOR WHAT COULD END UP
TO BE A VERY HIGH CAPE SETUP.

MARINE...

A WEAK AREA OF LOW PRESSURE WILL SLIDE ACROSS LOWER MICHIGAN TODAY
BRINGING A WEAK SOUTHEASTERLY WIND TO MANY AREAS. A SECOND WEAK AREA
OF LOW PRESSURE WILL PUSH INTO THE NORTHERN GREAT LAKES ON
FRIDAY...MAINTAINING A RATHER SIZABLE SURFACE TROUGH STRUCTURE OVER
THE GREAT LAKES REGION. OUTSIDE OF CONTINUAL SHOWER AND THUNDERSTORM
CHANCES...AN EXTENDED STRETCH OF MARINE WEATHER IS ANTICIPATED.

&&

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

&&

$$

AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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







000
FXUS63 KDTX 201127
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
727 AM EDT WED AUG 20 2014


.AVIATION...

//DISCUSSION...

SOME MORNING FOG WILL PLAGUE THE TAF SITES EARLY THIS MORNING...WITH
THE LOWEST CONDITIONS OF LIFR OVER MBS...WITH ONLY MVFR OVER THE
METRO AIRPORTS. THIS FOG IS EXPECTED TO LIFT LATER THIS MORNING WITH
THE ONSET OF DAYTIME HEATING. SHOWERS AND THUNDERSTORMS ARE AGAIN
EXPECTED THIS AFTERNOON AND EARLY THIS EVENING UNDERNEATH A MID
LEVEL LOW PRESSURE SYSTEM WITH INSTABILITY FROM DAYTIME HEATING.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING AOB 5000 FT THIS MORNING.

* MEDIUM CONFIDENCE IN THUNDERSTORM COVERAGE AND TIMING.

&&

.PREV DISCUSSION...ISSUED 357 AM EDT WED AUG 20 2014

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE TRACKED EAST AS A COLD FRONT HAS
SWEPT THROUGH THE CENTRAL GREAT LAKES. HOWEVER THIS COLD FRONT WILL
NOT BRING MUCH RELIEF WITH REGARDS TO MOISTURE AS DEW POINTS ARE
STILL IN THE LOWER TO MIDDLE 60S. THE LACK OF DRY AIR BEHIND THE
FRONT AND FAIRLY CALM WINDS BRINGS WITH IT THE POTENTIAL FOR FOG
ACROSS THE AREA. LINGERING CLOUDS SHOULD DELAY THE ONSET OF FOG
FORMATION...WITH AREAS TO THE EAST PROBABLY NOT GOING DOWN UNTIL
AROUND SUNRISE. ALTHOUGH THERE ARE EXPECTED TO BE AREAS OF DENSE FOG
THIS MORNING...IT IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO WARRANT
A DENSE FOG ADVISORY AT THIS POINT. HOWEVER IF VISIBILITIES DROP
SIGNIFICANTLY WILL ISSUE THE APPROPRIATE HEADLINES AS NEEDED. THE
LINGERING MOISTURE MAY STILL SPARK OFF SOME LIGHT SHOWER ACTIVITY
EARLY THIS MORNING AS A RIBBON OF HIGH LOW LEVEL THETA-E AIR REMAINS
OVER SOUTHEAST MICHIGAN.

DAYTIME HEATING WILL ONCE AGAIN CAUSE AN UNSTABLE ATMOSPHERE AS IT
COMBINES WITH A STILL MOIST BOUNDARY LAYER TO PRODUCE MUCAPES OF
1500 TO 2000 J/KG. THIS SHOULD ONCE AGAIN SPARK OFF THUNDERSTORMS
ACROSS THE AREA AS THE MID LEVEL LOW PRESSURE SYSTEM TRACKS THROUGH
THE SOO TODAY. HOWEVER UNLIKE YESTERDAY 0-6KM BULK SHEAR VALUES WILL
BE MUCH WEAKER AT AROUND 20 KNOTS...MAKING THE THREAT FOR SEVERE
WEATHER MUCH LOWER. STORMS TODAY MAY PRODUCE WIND GUSTS UP OF 40 TO
50 MPH WITH HAIL AROUND ONE HALF OF AN INCH UP TO DIME SIZE WITH THE
STRONGEST STORMS.

ALTHOUGH THE MID LEVEL LOW WILL REMAIN OVER LAKE HURON
OVERNIGHT...RAIN CHANCES WILL DROP OFF WITH THE LOSS OF DAYTIME
HEATING. RAIN SHOULD BE CONFINED TO THE AREAS NEAR THE LOW WHICH
WILL BE THE THUMB REGION...WITH CHANCES CREEPING IN ACROSS THE
EXTREME SOUTHERN CWA LATE TONIGHT AS A QUICK MOVING SHORTWAVE TRACKS
THROUGH THE SOUTHERN GREAT LAKES.

LONG TERM...

A LONGWAVE AMPLIFIED RIDGE AXIS WILL BUILD AGGRESSIVELY INTO
NORTHEASTERN NORTH AMERICA DURING THE NEXT 48 HOURS. IT GOES WITHOUT
SAYING...BUT AN EXTREMELY ATYPICAL EVENT FOR THIS SUMMER. WHAT THIS
WILL DO IS ESSENTIALLY THROW A CURVE BALL TO THE LOCAL WEATHER
PATTERN...LIKELY BRINGING IN THE LARGEST RUN OF SUMMER WARMTH THIS
REGION HAS SEEN ALL SEASON LONG. BEFORE THIS CAN REALLY BECOME
ESTABLISHED DURING THE LATTER HALF OF THE WEEKEND...SOUTHEASTERN
MICHIGAN WILL HAVE TO CONTEND WITH AN INTERNAL RIDGE STRUCTURE AND
SECONDARY JET CORE. IT IS THIS SECONDARY JET OVERHEAD THAT WILL
DIRECT SHORTWAVE ENERGY AND POTENTIAL RIDGE RIDER TYPE MCS INTO THE
AREA LIKELY ANYTIME THROUGH SATURDAY. AN ACTIVE PERIOD IS IN STORE
THROUGH THE END OF THE WEEK.

THURSDAY...A LOWER GEOPOTENTIAL HEIGHT ANOMALY WILL BUILD OFF OF
LAKE HURON AND INTO THE NORTHEASTERN UNITED STATES DURING THE DAY ON
FRIDAY. IT IS THE COMBINATION OF THIS ACTION AND AN UPPER LEVEL JET
CORE CRESTING THE RIDGE AXIS OVER THE PLAINS/NORTHERN MISSISSIPPI
RIVER VALLEY THAT THAT WILL FREEZE THE HEIGHT PATTERN OVER LOWER
MICHIGAN. QUITE THE GRADIENT IN TEMPERATURES IS EXPECTED WITH A
STATIONARY FRONTAL BOUNDARY DRAPED FROM PORTIONS OF OHIO
NORTHWESTWARD TO CENTRAL LOWER MICHIGAN NW TO PORTIONS OF THE U.P.
THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH KEEPING THE HEAT
TO THE SOUTHWEST. MODELS KEEP THE BULK OF THE CWA DRY...ALTHOUGH THE
FRONTAL BOUNDARY WILL BRING THE POTETNIAL FOR SHOWERS AND
THUNDERSTORMS PARTICULALRY SOUTH AND WEST OF M 59. TEMPERATURE
SHOULD TICK ABOVE THE 80 DEGREE MARK FOR MANY AREAS.

THE AFORMENTIONED 300MB JETLET IS FORECASTED TO CREST THE RIDGE
THURSDAY EVENING AND SLIDE DIRECTLY INTO SOUTHEASTERN MICHIGAN
THURSDAY NIGHT/FRIDAY MORNING. MODELS ARE EXTREMELY NOISY...BUT
OVERALL THERE IS A VERY GOOD SIGNAL THAT AN MCS COULD BUILD ACROSS
THE NORTHERN MISSSIPPI RIVER VALLEY THURSDAY AND RELEASE TOWARDS THE
AREA THURSDAY NIGHT. ALOT OF TIME TO FIGURE THIS OUT...BUT DEGREE OF
INSTABILITY IMMEDIATELY TO THE SOUTH DUE TO STRONG LAPSE RATES ALOFT
COULD LEAD TO SEVERE WEATHER RISK FRIDAY MORNING. ONE THING TO
MONIOR IS THE MCS WILL LIKELY ORGANIZED/INTENSIFY IN AN AREA OF
STRONG LEFT EXIT REGION DYNAMICS. THE OVERALL SYSTEM IS THEN SHOWN
TO OUTRUN THE UPPER LEVEL JET SUPPORT BY DIVING TO THE SOUTH.

FRIDAY...FRIDAY IS A DIFFICULT FORECAST PERIOD. WILL LIKELY NEED TO
COMBAT SUBSIDENCE AND MIDLEVEL LATENT HEATING LEFTOVER FROM THE MCS
IMPACTING THE REGION. UPPER LEVEL JET CORE WILL MAINTAIN ENOUGH
INTEGRITY TO BRING PESKY SHORTWAVE ENERGY INTO PLAY. MODELS SUPPORT
ADVECTING HIGH THETA E INTO THE STATE ENOUGH FOR WHAT COULD END UP
TO BE A VERY HIGH CAPE SETUP.

MARINE...

A WEAK AREA OF LOW PRESSURE WILL SLIDE ACROSS LOWER MICHIGAN TODAY
BRINGING A WEAK SOUTHEASTERLY WIND TO MANY AREAS. A SECOND WEAK AREA
OF LOW PRESSURE WILL PUSH INTO THE NORTHERN GREAT LAKES ON
FRIDAY...MAINTAINING A RATHER SIZABLE SURFACE TROUGH STRUCTURE OVER
THE GREAT LAKES REGION. OUTSIDE OF CONTINUAL SHOWER AND THUNDERSTORM
CHANCES...AN EXTENDED STRETCH OF MARINE WEATHER IS ANTICIPATED.

&&

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

&&

$$

AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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








000
FXUS63 KDTX 200757
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
357 AM EDT WED AUG 20 2014

.SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE TRACKED EAST AS A COLD FRONT HAS
SWEPT THROUGH THE CENTRAL GREAT LAKES. HOWEVER THIS COLD FRONT WILL
NOT BRING MUCH RELIEF WITH REGARDS TO MOISTURE AS DEW POINTS ARE
STILL IN THE LOWER TO MIDDLE 60S. THE LACK OF DRY AIR BEHIND THE
FRONT AND FAIRLY CALM WINDS BRINGS WITH IT THE POTENTIAL FOR FOG
ACROSS THE AREA. LINGERING CLOUDS SHOULD DELAY THE ONSET OF FOG
FORMATION...WITH AREAS TO THE EAST PROBABLY NOT GOING DOWN UNTIL
AROUND SUNRISE. ALTHOUGH THERE ARE EXPECTED TO BE AREAS OF DENSE FOG
THIS MORNING...IT IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO WARRANT
A DENSE FOG ADVISORY AT THIS POINT. HOWEVER IF VISIBILITIES DROP
SIGNIFICANTLY WILL ISSUE THE APPROPRIATE HEADLINES AS NEEDED. THE
LINGERING MOISTURE MAY STILL SPARK OFF SOME LIGHT SHOWER ACTIVITY
EARLY THIS MORNING AS A RIBBON OF HIGH LOW LEVEL THETA-E AIR REMAINS
OVER SOUTHEAST MICHIGAN.

DAYTIME HEATING WILL ONCE AGAIN CAUSE AN UNSTABLE ATMOSPHERE AS IT
COMBINES WITH A STILL MOIST BOUNDARY LAYER TO PRODUCE MUCAPES OF
1500 TO 2000 J/KG. THIS SHOULD ONCE AGAIN SPARK OFF THUNDERSTORMS
ACROSS THE AREA AS THE MID LEVEL LOW PRESSURE SYSTEM TRACKS THROUGH
THE SOO TODAY. HOWEVER UNLIKE YESTERDAY 0-6KM BULK SHEAR VALUES WILL
BE MUCH WEAKER AT AROUND 20 KNOTS...MAKING THE THREAT FOR SEVERE
WEATHER MUCH LOWER. STORMS TODAY MAY PRODUCE WIND GUSTS UP OF 40 TO
50 MPH WITH HAIL AROUND ONE HALF OF AN INCH UP TO DIME SIZE WITH THE
STRONGEST STORMS.

ALTHOUGH THE MID LEVEL LOW WILL REMAIN OVER LAKE HURON
OVERNIGHT...RAIN CHANCES WILL DROP OFF WITH THE LOSS OF DAYTIME
HEATING. RAIN SHOULD BE CONFINED TO THE AREAS NEAR THE LOW WHICH
WILL BE THE THUMB REGION...WITH CHANCES CREEPING IN ACROSS THE
EXTREME SOUTHERN CWA LATE TONIGHT AS A QUICK MOVING SHORTWAVE TRACKS
THROUGH THE SOUTHERN GREAT LAKES.

&&

.LONG TERM...

A LONGWAVE AMPLIFIED RIDGE AXIS WILL BUILD AGGRESSIVELY INTO
NORTHEASTERN NORTH AMERICA DURING THE NEXT 48 HOURS. IT GOES WITHOUT
SAYING...BUT AN EXTREMELY ATYPICAL EVENT FOR THIS SUMMER. WHAT THIS
WILL DO IS ESSENTIALLY THROW A CURVE BALL TO THE LOCAL WEATHER
PATTERN...LIKELY BRINGING IN THE LARGEST RUN OF SUMMER WARMTH THIS
REGION HAS SEEN ALL SEASON LONG. BEFORE THIS CAN REALLY BECOME
ESTABLISHED DURING THE LATTER HALF OF THE WEEKEND...SOUTHEASTERN
MICHIGAN WILL HAVE TO CONTEND WITH AN INTERNAL RIDGE STRUCTURE AND
SECONDARY JET CORE. IT IS THIS SECONDARY JET OVERHEAD THAT WILL
DIRECT SHORTWAVE ENERGY AND POTENTIAL RIDGE RIDER TYPE MCS INTO THE
AREA LIKELY ANYTIME THROUGH SATURDAY. AN ACTIVE PERIOD IS IN STORE
THROUGH THE END OF THE WEEK.

THURSDAY...A LOWER GEOPOTENTIAL HEIGHT ANOMALY WILL BUILD OFF OF
LAKE HURON AND INTO THE NORTHEASTERN UNITED STATES DURING THE DAY ON
FRIDAY. IT IS THE COMBINATION OF THIS ACTION AND AN UPPER LEVEL JET
CORE CRESTING THE RIDGE AXIS OVER THE PLAINS/NORTHERN MISSISSIPPI
RIVER VALLEY THAT THAT WILL FREEZE THE HEIGHT PATTERN OVER LOWER
MICHIGAN. QUITE THE GRADIENT IN TEMPERATURES IS EXPECTED WITH A
STATIONARY FRONTAL BOUNDARY DRAPED FROM PORTIONS OF OHIO
NORTHWESTWARD TO CENTRAL LOWER MICHIGAN NW TO PORTIONS OF THE U.P.
THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH KEEPING THE HEAT
TO THE SOUTHWEST. MODELS KEEP THE BULK OF THE CWA DRY...ALTHOUGH THE
FRONTAL BOUNDARY WILL BRING THE POTETNIAL FOR SHOWERS AND
THUNDERSTORMS PARTICULALRY SOUTH AND WEST OF M 59. TEMPERATURE
SHOULD TICK ABOVE THE 80 DEGREE MARK FOR MANY AREAS.

THE AFORMENTIONED 300MB JETLET IS FORECASTED TO CREST THE RIDGE
THURSDAY EVENING AND SLIDE DIRECTLY INTO SOUTHEASTERN MICHIGAN
THURSDAY NIGHT/FRIDAY MORNING. MODELS ARE EXTREMELY NOISY...BUT
OVERALL THERE IS A VERY GOOD SIGNAL THAT AN MCS COULD BUILD ACROSS
THE NORTHERN MISSSIPPI RIVER VALLEY THURSDAY AND RELEASE TOWARDS THE
AREA THURSDAY NIGHT. ALOT OF TIME TO FIGURE THIS OUT...BUT DEGREE OF
INSTABILITY IMMEDIATELY TO THE SOUTH DUE TO STRONG LAPSE RATES ALOFT
COULD LEAD TO SEVERE WEATHER RISK FRIDAY MORNING. ONE THING TO
MONIOR IS THE MCS WILL LIKELY ORGANIZED/INTENSIFY IN AN AREA OF
STRONG LEFT EXIT REGION DYNAMICS. THE OVERALL SYSTEM IS THEN SHOWN
TO OUTRUN THE UPPER LEVEL JET SUPPORT BY DIVING TO THE SOUTH.

FRIDAY...FRIDAY IS A DIFFICULT FORECAST PERIOD. WILL LIKELY NEED TO
COMBAT SUBSIDENCE AND MIDLEVEL LATENT HEATING LEFTOVER FROM THE MCS
IMPACTING THE REGION. UPPER LEVEL JET CORE WILL MAINTAIN ENOUGH
INTEGRITY TO BRING PESKY SHORTWAVE ENERGY INTO PLAY. MODELS SUPPORT
ADVECTING HIGH THETA E INTO THE STATE ENOUGH FOR WHAT COULD END UP
TO BE A VERY HIGH CAPE SETUP.

&&

.MARINE...

A WEAK AREA OF LOW PRESSURE WILL SLIDE ACROSS LOWER MICHIGAN TODAY
BRINGING A WEAK SOUTHEASTERLY WIND TO MANY AREAS. A SECOND WEAK AREA
OF LOW PRESSURE WILL PUSH INTO THE NORTHERN GREAT LAKES ON
FRIDAY...MAINTAINING A RATHER SIZABLE SURFACE TROUGH STRUCTURE OVER
THE GREAT LAKES REGION. OUTSIDE OF CONTINUAL SHOWER AND THUNDERSTORM
CHANCES...AN EXTENDED STRETCH OF MARINE WEATHER IS ANTICIPATED.

&&

.AVIATION...ISSUED 1207 AM EDT WED AUG 20 2014

//DISCUSSION...

UPPER LEVEL LOW PRESSURE SPINNING OVER THE GREAT LAKES WILL SUPPORT
SCATTERED THUNDERSTORM COVERAGE DURING THE EARLY MORNING. THE LATEST
RADAR TREND INDICATES FNT AND THE DTW CORRIDOR MOST LIKELY TO
AFFECTED IN THE 06-09Z TIME WINDOW. IN BETWEEN AND AFTER...VARYING
AMOUNTS OF MID AND HIGH CLOUDS WILL ALLOW ENOUGH BOUNDARY LAYER
COOLING FOR FOG DEVELOPMENT. IFR CONDITIONS WILL INITIALLY CONSIST OF
STRATUS BUT THEN COMBINE WITH FOG THROUGH MID WEDNESDAY MORNING AS
THE UPSTREAM SURFACE LOW DRIFTS INTO NORTHERN LOWER MICHIGAN. A
TYPICAL CYCLE OF CEILING AND VISIBILITY IMPROVEMENT WILL THEN BE
ACCOMPANIED BY INCREASING SHOWER COVERAGE WITH DAYTIME HEATING
DURING THE AFTERNOON INTO WEDNESDAY EVENING.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING AOB 5000 FT THROUGH MORNING.

* MEDIUM CONFIDENCE IN THUNDERSTORM COVERAGE AND TIMING.

* LOW CONFIDENCE IN CEILING AOB 200 FT/VISIBILITY 1/2SM AROUND
  SUNRISE.

&&

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

&&

$$

SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB
AVIATION.....BT


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







000
FXUS63 KDTX 200757
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
357 AM EDT WED AUG 20 2014

.SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE TRACKED EAST AS A COLD FRONT HAS
SWEPT THROUGH THE CENTRAL GREAT LAKES. HOWEVER THIS COLD FRONT WILL
NOT BRING MUCH RELIEF WITH REGARDS TO MOISTURE AS DEW POINTS ARE
STILL IN THE LOWER TO MIDDLE 60S. THE LACK OF DRY AIR BEHIND THE
FRONT AND FAIRLY CALM WINDS BRINGS WITH IT THE POTENTIAL FOR FOG
ACROSS THE AREA. LINGERING CLOUDS SHOULD DELAY THE ONSET OF FOG
FORMATION...WITH AREAS TO THE EAST PROBABLY NOT GOING DOWN UNTIL
AROUND SUNRISE. ALTHOUGH THERE ARE EXPECTED TO BE AREAS OF DENSE FOG
THIS MORNING...IT IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO WARRANT
A DENSE FOG ADVISORY AT THIS POINT. HOWEVER IF VISIBILITIES DROP
SIGNIFICANTLY WILL ISSUE THE APPROPRIATE HEADLINES AS NEEDED. THE
LINGERING MOISTURE MAY STILL SPARK OFF SOME LIGHT SHOWER ACTIVITY
EARLY THIS MORNING AS A RIBBON OF HIGH LOW LEVEL THETA-E AIR REMAINS
OVER SOUTHEAST MICHIGAN.

DAYTIME HEATING WILL ONCE AGAIN CAUSE AN UNSTABLE ATMOSPHERE AS IT
COMBINES WITH A STILL MOIST BOUNDARY LAYER TO PRODUCE MUCAPES OF
1500 TO 2000 J/KG. THIS SHOULD ONCE AGAIN SPARK OFF THUNDERSTORMS
ACROSS THE AREA AS THE MID LEVEL LOW PRESSURE SYSTEM TRACKS THROUGH
THE SOO TODAY. HOWEVER UNLIKE YESTERDAY 0-6KM BULK SHEAR VALUES WILL
BE MUCH WEAKER AT AROUND 20 KNOTS...MAKING THE THREAT FOR SEVERE
WEATHER MUCH LOWER. STORMS TODAY MAY PRODUCE WIND GUSTS UP OF 40 TO
50 MPH WITH HAIL AROUND ONE HALF OF AN INCH UP TO DIME SIZE WITH THE
STRONGEST STORMS.

ALTHOUGH THE MID LEVEL LOW WILL REMAIN OVER LAKE HURON
OVERNIGHT...RAIN CHANCES WILL DROP OFF WITH THE LOSS OF DAYTIME
HEATING. RAIN SHOULD BE CONFINED TO THE AREAS NEAR THE LOW WHICH
WILL BE THE THUMB REGION...WITH CHANCES CREEPING IN ACROSS THE
EXTREME SOUTHERN CWA LATE TONIGHT AS A QUICK MOVING SHORTWAVE TRACKS
THROUGH THE SOUTHERN GREAT LAKES.

&&

.LONG TERM...

A LONGWAVE AMPLIFIED RIDGE AXIS WILL BUILD AGGRESSIVELY INTO
NORTHEASTERN NORTH AMERICA DURING THE NEXT 48 HOURS. IT GOES WITHOUT
SAYING...BUT AN EXTREMELY ATYPICAL EVENT FOR THIS SUMMER. WHAT THIS
WILL DO IS ESSENTIALLY THROW A CURVE BALL TO THE LOCAL WEATHER
PATTERN...LIKELY BRINGING IN THE LARGEST RUN OF SUMMER WARMTH THIS
REGION HAS SEEN ALL SEASON LONG. BEFORE THIS CAN REALLY BECOME
ESTABLISHED DURING THE LATTER HALF OF THE WEEKEND...SOUTHEASTERN
MICHIGAN WILL HAVE TO CONTEND WITH AN INTERNAL RIDGE STRUCTURE AND
SECONDARY JET CORE. IT IS THIS SECONDARY JET OVERHEAD THAT WILL
DIRECT SHORTWAVE ENERGY AND POTENTIAL RIDGE RIDER TYPE MCS INTO THE
AREA LIKELY ANYTIME THROUGH SATURDAY. AN ACTIVE PERIOD IS IN STORE
THROUGH THE END OF THE WEEK.

THURSDAY...A LOWER GEOPOTENTIAL HEIGHT ANOMALY WILL BUILD OFF OF
LAKE HURON AND INTO THE NORTHEASTERN UNITED STATES DURING THE DAY ON
FRIDAY. IT IS THE COMBINATION OF THIS ACTION AND AN UPPER LEVEL JET
CORE CRESTING THE RIDGE AXIS OVER THE PLAINS/NORTHERN MISSISSIPPI
RIVER VALLEY THAT THAT WILL FREEZE THE HEIGHT PATTERN OVER LOWER
MICHIGAN. QUITE THE GRADIENT IN TEMPERATURES IS EXPECTED WITH A
STATIONARY FRONTAL BOUNDARY DRAPED FROM PORTIONS OF OHIO
NORTHWESTWARD TO CENTRAL LOWER MICHIGAN NW TO PORTIONS OF THE U.P.
THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH KEEPING THE HEAT
TO THE SOUTHWEST. MODELS KEEP THE BULK OF THE CWA DRY...ALTHOUGH THE
FRONTAL BOUNDARY WILL BRING THE POTETNIAL FOR SHOWERS AND
THUNDERSTORMS PARTICULALRY SOUTH AND WEST OF M 59. TEMPERATURE
SHOULD TICK ABOVE THE 80 DEGREE MARK FOR MANY AREAS.

THE AFORMENTIONED 300MB JETLET IS FORECASTED TO CREST THE RIDGE
THURSDAY EVENING AND SLIDE DIRECTLY INTO SOUTHEASTERN MICHIGAN
THURSDAY NIGHT/FRIDAY MORNING. MODELS ARE EXTREMELY NOISY...BUT
OVERALL THERE IS A VERY GOOD SIGNAL THAT AN MCS COULD BUILD ACROSS
THE NORTHERN MISSSIPPI RIVER VALLEY THURSDAY AND RELEASE TOWARDS THE
AREA THURSDAY NIGHT. ALOT OF TIME TO FIGURE THIS OUT...BUT DEGREE OF
INSTABILITY IMMEDIATELY TO THE SOUTH DUE TO STRONG LAPSE RATES ALOFT
COULD LEAD TO SEVERE WEATHER RISK FRIDAY MORNING. ONE THING TO
MONIOR IS THE MCS WILL LIKELY ORGANIZED/INTENSIFY IN AN AREA OF
STRONG LEFT EXIT REGION DYNAMICS. THE OVERALL SYSTEM IS THEN SHOWN
TO OUTRUN THE UPPER LEVEL JET SUPPORT BY DIVING TO THE SOUTH.

FRIDAY...FRIDAY IS A DIFFICULT FORECAST PERIOD. WILL LIKELY NEED TO
COMBAT SUBSIDENCE AND MIDLEVEL LATENT HEATING LEFTOVER FROM THE MCS
IMPACTING THE REGION. UPPER LEVEL JET CORE WILL MAINTAIN ENOUGH
INTEGRITY TO BRING PESKY SHORTWAVE ENERGY INTO PLAY. MODELS SUPPORT
ADVECTING HIGH THETA E INTO THE STATE ENOUGH FOR WHAT COULD END UP
TO BE A VERY HIGH CAPE SETUP.

&&

.MARINE...

A WEAK AREA OF LOW PRESSURE WILL SLIDE ACROSS LOWER MICHIGAN TODAY
BRINGING A WEAK SOUTHEASTERLY WIND TO MANY AREAS. A SECOND WEAK AREA
OF LOW PRESSURE WILL PUSH INTO THE NORTHERN GREAT LAKES ON
FRIDAY...MAINTAINING A RATHER SIZABLE SURFACE TROUGH STRUCTURE OVER
THE GREAT LAKES REGION. OUTSIDE OF CONTINUAL SHOWER AND THUNDERSTORM
CHANCES...AN EXTENDED STRETCH OF MARINE WEATHER IS ANTICIPATED.

&&

.AVIATION...ISSUED 1207 AM EDT WED AUG 20 2014

//DISCUSSION...

UPPER LEVEL LOW PRESSURE SPINNING OVER THE GREAT LAKES WILL SUPPORT
SCATTERED THUNDERSTORM COVERAGE DURING THE EARLY MORNING. THE LATEST
RADAR TREND INDICATES FNT AND THE DTW CORRIDOR MOST LIKELY TO
AFFECTED IN THE 06-09Z TIME WINDOW. IN BETWEEN AND AFTER...VARYING
AMOUNTS OF MID AND HIGH CLOUDS WILL ALLOW ENOUGH BOUNDARY LAYER
COOLING FOR FOG DEVELOPMENT. IFR CONDITIONS WILL INITIALLY CONSIST OF
STRATUS BUT THEN COMBINE WITH FOG THROUGH MID WEDNESDAY MORNING AS
THE UPSTREAM SURFACE LOW DRIFTS INTO NORTHERN LOWER MICHIGAN. A
TYPICAL CYCLE OF CEILING AND VISIBILITY IMPROVEMENT WILL THEN BE
ACCOMPANIED BY INCREASING SHOWER COVERAGE WITH DAYTIME HEATING
DURING THE AFTERNOON INTO WEDNESDAY EVENING.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING AOB 5000 FT THROUGH MORNING.

* MEDIUM CONFIDENCE IN THUNDERSTORM COVERAGE AND TIMING.

* LOW CONFIDENCE IN CEILING AOB 200 FT/VISIBILITY 1/2SM AROUND
  SUNRISE.

&&

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

&&

$$

SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB
AVIATION.....BT


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








000
FXUS63 KDTX 200407
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1207 AM EDT WED AUG 20 2014

.AVIATION...

//DISCUSSION...

UPPER LEVEL LOW PRESSURE SPINNING OVER THE GREAT LAKES WILL SUPPORT
SCATTERED THUNDERSTORM COVERAGE DURING THE EARLY MORNING. THE LATEST
RADAR TREND INDICATES FNT AND THE DTW CORRIDOR MOST LIKELY TO
AFFECTED IN THE 06-09Z TIME WINDOW. IN BETWEEN AND AFTER...VARYING
AMOUNTS OF MID AND HIGH CLOUDS WILL ALLOW ENOUGH BOUNDARY LAYER
COOLING FOR FOG DEVELOPMENT. IFR CONDITIONS WILL INITIALLY CONSIST OF
STRATUS BUT THEN COMBINE WITH FOG THROUGH MID WEDNESDAY MORNING AS
THE UPSTREAM SURFACE LOW DRIFTS INTO NORTHERN LOWER MICHIGAN. A
TYPICAL CYCLE OF CEILING AND VISIBILITY IMPROVEMENT WILL THEN BE
ACCOMPANIED BY INCREASING SHOWER COVERAGE WITH DAYTIME HEATING
DURING THE AFTERNOON INTO WEDNESDAY EVENING.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING AOB 5000 FT THROUGH MORNING.

* MEDIUM CONFIDENCE IN THUNDERSTORM COVERAGE AND TIMING.

* LOW CONFIDENCE IN CEILING AOB 200 FT/VISIBILITY 1/2SM AROUND
  SUNRISE.

&&

.PREV DISCUSSION...ISSUED 1027 PM EDT TUE AUG 19 2014

UPDATE...

THE EARLIER UPDATE MAINTAINED A CHANCE OF SHOWERS AND STORMS AND
ADDED FOG TO THE FORECAST FOR OVERNIGHT THROUGH MID WEDNESDAY
MORNING. THE COOL AND MOIST BOUNDARY LAYER IS PRIMED FOR FOG
DEVELOPMENT OVER THE TOP OF WET GROUND. LATE EVENING OBSERVATIONS
INDICATE MOSTLY A 1 TO 3 DEGREE SURFACE TEMP/DEWPOINT SPREAD
SUGGESTING FOG WILL DEVELOP QUICKLY UNDER ANY OPEN SKY. THE TIMING
AND EXTENT OF CLEARING IS THE MORE CHALLENGING QUESTION. SO
FAR...WEAK GRADIENT FLOW HAS LED TO STRATUS FORMATION IN THE
SAGINAW VALLEY WHERE MID AND HIGH CLOUDS HAVE PARTIALLY CLEARED
AWAY. AT THE SAME TIME...HOURLY MESOANALYSIS AND MODEL SOUNDINGS
INDICATE ENOUGH ELEVATED INSTABILITY LINGERING UNDER THE UPPER LOW
TO MAINTAIN AREAS OF MID TO HIGH CLOUDS AND SCATTERED COVERAGE OF
SHOWERS...AT LEAST FOR A WHILE. EXPECT THE SAGINAW VALLEY STRATUS TO
BUILD TOWARD THE SURFACE DURING THE NIGHT AND MORE OF AN INITIAL
FOG FORMATION IN THE DTW AREA AS GRADIENT FLOW WEAKENS IN ALL
AREAS AND AS HIGH CLOUDS DIMINISH LATER ON...BUT LOW CONFIDENCE
IN THE CLOUD TRENDS PREVENTS A MENTION OF DENSE FOG FOR NOW.

PREV DISCUSSION...ISSUED 318 PM EDT TUE AUG 19 2014

SHORT TERM...

WITH MLCAPES APPROACHING 2000 J/KG OVER PARTS OF THE CWA NOW THAT
THE BOUNDARY LAYER HAS RECOVERED FROM MORNING CONVECTION...EXPECT
WIDESPREAD SHOWERS AND THUNDERSTORMS TO OVERSPREAD SOUTHEAST
MICHIGAN DURING THE REST OF THE AFTERNOON INTO THIS EVENING. THIS
ACTIVITY WILL SHIFT SOUTHEAST WITH TIME AS AN APPROACHING COLD
FRONT SHIFTS INTO THE REGION.

GIVEN THE DEGREE OF INSTABILITY...AND MODEST DEEP LAYER SHEAR IN
THE NEIGHBORHOOD OF 25-30 KNOTS...SOME OF THESE STORMS WILL MOST
LIKELY BECOME SEVERE. THE BOUNDARY LAYER WILL BE WELL MIXED AS
STORMS MOVE INTO THE AREA...SO DAMAGING WIND GUSTS WILL BE
POSSIBLE WITH THE STRONGEST STORMS.

HEAVY RAINFALL BE A BIGGER CONCERN AS PRECIPITABLE WATER
INCREASES TO 1.75-2.00 INCHES WITHIN BEST PLUME OF DEEP MOISTURE
FUNNELING NORTHEAST INTO AREA IN ADVANCE OF APPROACHING COLD
FRONT/UPPER TROUGH AXIS. AS ADDITIONAL CONVECTION RIDES NORTHEAST
INTO AREA WITH APPROACHING DISTURBANCE OVER NORTHWEST
INDIANA...THE COVERAGE OF HEAVY RAINFALL WILL INCREASE AND FOCUS
GENERALLY SOUTH OF I 69...AND ESPECIALLY BETWEEN THE M 59 AND I 94
CORRIDORS.

A SEVERE THUNDERSTORM WATCH WILL CONTINUE FROM THE M 59 COUNTIES
SOUTHWARD WITH A FLASH FLOOD WATCH CENTERED ON THE METRO DETROIT
AREA AS RUNOFF IN THE URBAN AREAS IS ENHANCED. A BULK OF THIS
ACTIVITY WILL SHIFT SOUTH AND EAST OF THE AREA THIS EVENING...BUT
LINGERING SCATTERED SHOWERS OR A FEW STORMS WILL REMAIN POSSIBLE.

LONG TERM...

THE AREA ACTUALLY TRANSITIONS INTO A MORE SUMMERLIKE PATTERN LATE
THIS WEEK INTO THE WEEKEND AS THE AN UPPER RIDGE EXPANDS INTO THE
EASTERN CONUS. THIS RIDGE ACTUALLY PERSISTS INTO EARLY NEXT WEEK
BEFORE SETTLING SOUTHEAST. THIS PATTERN WILL BRING AN EXTENDED
PERIOD OF WARMER WEATHER WITH TEMPERATURES WELL INTO THE 80S FROM
LATE THIS WEEK ON THROUGH THE REMAINDER OF THE LONG TERM FORECAST
PERIOD. IN FACT...90 DEGREE READINGS WILL BE POSSIBLE AT TIMES.

THIS BUILDING HEAT AND HUMIDITY WILL ALSO BRING PERIODIC SHOWERS
AND THUNDERSTORMS...PARTICULARLY DURING THE COURSE OF THIS WEEK AS
THE TRANSITION IN THE UPPER LEVEL PATTERN OCCURS AND SHORTWAVE
DISTURBANCES RIDE ALONG THE NORTH AND NORTHEAST EDGE OF THIS
FEATURE AS IT EXPANDS INTO THE GREAT LAKES.

MARINE...

SHOWERS AND THUNDERSTORMS WILL EXPAND OVER THE AREA INTO THIS
EVENING AS LOW PRESSURE PUSHES A COLD FRONT INTO THE REGION. THIS
LOW WILL SLOWLY WOBBLE THROUGH THE AREA THROUGH THE MIDDLE OF THE
WEEK AND MAINTAIN PERIODS OF SHOWERS AND THUNDERSTORMS.

IN GENERAL...HOWEVER...WIND AND WAVE CONDITIONS...OUTSIDE OF
THUNDERSTORMS...WILL REMAIN IN CHECK THIS WEEK AS UPPER RIDING
BUILDS INTO THE AREA.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

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


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









000
FXUS63 KDTX 200407
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1207 AM EDT WED AUG 20 2014

.AVIATION...

//DISCUSSION...

UPPER LEVEL LOW PRESSURE SPINNING OVER THE GREAT LAKES WILL SUPPORT
SCATTERED THUNDERSTORM COVERAGE DURING THE EARLY MORNING. THE LATEST
RADAR TREND INDICATES FNT AND THE DTW CORRIDOR MOST LIKELY TO
AFFECTED IN THE 06-09Z TIME WINDOW. IN BETWEEN AND AFTER...VARYING
AMOUNTS OF MID AND HIGH CLOUDS WILL ALLOW ENOUGH BOUNDARY LAYER
COOLING FOR FOG DEVELOPMENT. IFR CONDITIONS WILL INITIALLY CONSIST OF
STRATUS BUT THEN COMBINE WITH FOG THROUGH MID WEDNESDAY MORNING AS
THE UPSTREAM SURFACE LOW DRIFTS INTO NORTHERN LOWER MICHIGAN. A
TYPICAL CYCLE OF CEILING AND VISIBILITY IMPROVEMENT WILL THEN BE
ACCOMPANIED BY INCREASING SHOWER COVERAGE WITH DAYTIME HEATING
DURING THE AFTERNOON INTO WEDNESDAY EVENING.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING AOB 5000 FT THROUGH MORNING.

* MEDIUM CONFIDENCE IN THUNDERSTORM COVERAGE AND TIMING.

* LOW CONFIDENCE IN CEILING AOB 200 FT/VISIBILITY 1/2SM AROUND
  SUNRISE.

&&

.PREV DISCUSSION...ISSUED 1027 PM EDT TUE AUG 19 2014

UPDATE...

THE EARLIER UPDATE MAINTAINED A CHANCE OF SHOWERS AND STORMS AND
ADDED FOG TO THE FORECAST FOR OVERNIGHT THROUGH MID WEDNESDAY
MORNING. THE COOL AND MOIST BOUNDARY LAYER IS PRIMED FOR FOG
DEVELOPMENT OVER THE TOP OF WET GROUND. LATE EVENING OBSERVATIONS
INDICATE MOSTLY A 1 TO 3 DEGREE SURFACE TEMP/DEWPOINT SPREAD
SUGGESTING FOG WILL DEVELOP QUICKLY UNDER ANY OPEN SKY. THE TIMING
AND EXTENT OF CLEARING IS THE MORE CHALLENGING QUESTION. SO
FAR...WEAK GRADIENT FLOW HAS LED TO STRATUS FORMATION IN THE
SAGINAW VALLEY WHERE MID AND HIGH CLOUDS HAVE PARTIALLY CLEARED
AWAY. AT THE SAME TIME...HOURLY MESOANALYSIS AND MODEL SOUNDINGS
INDICATE ENOUGH ELEVATED INSTABILITY LINGERING UNDER THE UPPER LOW
TO MAINTAIN AREAS OF MID TO HIGH CLOUDS AND SCATTERED COVERAGE OF
SHOWERS...AT LEAST FOR A WHILE. EXPECT THE SAGINAW VALLEY STRATUS TO
BUILD TOWARD THE SURFACE DURING THE NIGHT AND MORE OF AN INITIAL
FOG FORMATION IN THE DTW AREA AS GRADIENT FLOW WEAKENS IN ALL
AREAS AND AS HIGH CLOUDS DIMINISH LATER ON...BUT LOW CONFIDENCE
IN THE CLOUD TRENDS PREVENTS A MENTION OF DENSE FOG FOR NOW.

PREV DISCUSSION...ISSUED 318 PM EDT TUE AUG 19 2014

SHORT TERM...

WITH MLCAPES APPROACHING 2000 J/KG OVER PARTS OF THE CWA NOW THAT
THE BOUNDARY LAYER HAS RECOVERED FROM MORNING CONVECTION...EXPECT
WIDESPREAD SHOWERS AND THUNDERSTORMS TO OVERSPREAD SOUTHEAST
MICHIGAN DURING THE REST OF THE AFTERNOON INTO THIS EVENING. THIS
ACTIVITY WILL SHIFT SOUTHEAST WITH TIME AS AN APPROACHING COLD
FRONT SHIFTS INTO THE REGION.

GIVEN THE DEGREE OF INSTABILITY...AND MODEST DEEP LAYER SHEAR IN
THE NEIGHBORHOOD OF 25-30 KNOTS...SOME OF THESE STORMS WILL MOST
LIKELY BECOME SEVERE. THE BOUNDARY LAYER WILL BE WELL MIXED AS
STORMS MOVE INTO THE AREA...SO DAMAGING WIND GUSTS WILL BE
POSSIBLE WITH THE STRONGEST STORMS.

HEAVY RAINFALL BE A BIGGER CONCERN AS PRECIPITABLE WATER
INCREASES TO 1.75-2.00 INCHES WITHIN BEST PLUME OF DEEP MOISTURE
FUNNELING NORTHEAST INTO AREA IN ADVANCE OF APPROACHING COLD
FRONT/UPPER TROUGH AXIS. AS ADDITIONAL CONVECTION RIDES NORTHEAST
INTO AREA WITH APPROACHING DISTURBANCE OVER NORTHWEST
INDIANA...THE COVERAGE OF HEAVY RAINFALL WILL INCREASE AND FOCUS
GENERALLY SOUTH OF I 69...AND ESPECIALLY BETWEEN THE M 59 AND I 94
CORRIDORS.

A SEVERE THUNDERSTORM WATCH WILL CONTINUE FROM THE M 59 COUNTIES
SOUTHWARD WITH A FLASH FLOOD WATCH CENTERED ON THE METRO DETROIT
AREA AS RUNOFF IN THE URBAN AREAS IS ENHANCED. A BULK OF THIS
ACTIVITY WILL SHIFT SOUTH AND EAST OF THE AREA THIS EVENING...BUT
LINGERING SCATTERED SHOWERS OR A FEW STORMS WILL REMAIN POSSIBLE.

LONG TERM...

THE AREA ACTUALLY TRANSITIONS INTO A MORE SUMMERLIKE PATTERN LATE
THIS WEEK INTO THE WEEKEND AS THE AN UPPER RIDGE EXPANDS INTO THE
EASTERN CONUS. THIS RIDGE ACTUALLY PERSISTS INTO EARLY NEXT WEEK
BEFORE SETTLING SOUTHEAST. THIS PATTERN WILL BRING AN EXTENDED
PERIOD OF WARMER WEATHER WITH TEMPERATURES WELL INTO THE 80S FROM
LATE THIS WEEK ON THROUGH THE REMAINDER OF THE LONG TERM FORECAST
PERIOD. IN FACT...90 DEGREE READINGS WILL BE POSSIBLE AT TIMES.

THIS BUILDING HEAT AND HUMIDITY WILL ALSO BRING PERIODIC SHOWERS
AND THUNDERSTORMS...PARTICULARLY DURING THE COURSE OF THIS WEEK AS
THE TRANSITION IN THE UPPER LEVEL PATTERN OCCURS AND SHORTWAVE
DISTURBANCES RIDE ALONG THE NORTH AND NORTHEAST EDGE OF THIS
FEATURE AS IT EXPANDS INTO THE GREAT LAKES.

MARINE...

SHOWERS AND THUNDERSTORMS WILL EXPAND OVER THE AREA INTO THIS
EVENING AS LOW PRESSURE PUSHES A COLD FRONT INTO THE REGION. THIS
LOW WILL SLOWLY WOBBLE THROUGH THE AREA THROUGH THE MIDDLE OF THE
WEEK AND MAINTAIN PERIODS OF SHOWERS AND THUNDERSTORMS.

IN GENERAL...HOWEVER...WIND AND WAVE CONDITIONS...OUTSIDE OF
THUNDERSTORMS...WILL REMAIN IN CHECK THIS WEEK AS UPPER RIDING
BUILDS INTO THE AREA.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

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


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








000
FXUS63 KDTX 200227
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1027 PM EDT TUE AUG 19 2014

.UPDATE...

THE EARLIER UPDATE MAINTAINED A CHANCE OF SHOWERS AND STORMS AND
ADDED FOG TO THE FORECAST FOR OVERNIGHT THROUGH MID WEDNESDAY
MORNING. THE COOL AND MOIST BOUNDARY LAYER IS PRIMED FOR FOG
DEVELOPMENT OVER THE TOP OF WET GROUND. LATE EVENING OBSERVATIONS
INDICATE MOSTLY A 1 TO 3 DEGREE SURFACE TEMP/DEWPOINT SPREAD
SUGGESTING FOG WILL DEVELOP QUICKLY UNDER ANY OPEN SKY. THE TIMING
AND EXTENT OF CLEARING IS THE MORE CHALLENGING QUESTION. SO
FAR...WEAK GRADIENT FLOW HAS LED TO STRATUS FORMATION IN THE
SAGINAW VALLEY WHERE MID AND HIGH CLOUDS HAVE PARTIALLY CLEARED
AWAY. AT THE SAME TIME...HOURLY MESOANALYSIS AND MODEL SOUNDINGS
INDICATE ENOUGH ELEVATED INSTABILITY LINGERING UNDER THE UPPER LOW
TO MAINTAIN AREAS OF MID TO HIGH CLOUDS AND SCATTERED COVERAGE OF
SHOWERS...AT LEAST FOR A WHILE. EXPECT THE SAGINAW VALLEY STRATUS TO
BUILD TOWARD THE SURFACE DURING THE NIGHT AND MORE OF AN INITIAL
FOG FORMATION IN THE DTW AREA AS GRADIENT FLOW WEAKENS IN ALL
AREAS AND AS HIGH CLOUDS DIMINISH LATER ON...BUT LOW CONFIDENCE
IN THE CLOUD TRENDS PREVENTS A MENTION OF DENSE FOG FOR NOW.

&&

.AVIATION...ISSUED 657 PM EDT TUE AUG 19 2014

//DISCUSSION...

THE PRIMARY AREA OF THUNDERSTORMS HAS MOVED EAST OF THE TERMINAL
SITES AT PRESS TIME. SECONDARY DEVELOPMENT WAS NOTED OVER WESTERN
LOWER MICHIGAN BUT THIS IS NOT EXPECTED TO ATTAIN THE COVERAGE OF
ROUND 1 AND WILL BE HANDLED WITH EVENING UPDATES SHOULD ANY ACTIVITY
SURVIVE THE LOSS OF DAYTIME HEATING WHILE MOVING INTO SE MICHIGAN.
OBSERVATIONS ALSO INDICATE INCREASING COVERAGE OF MVFR/MARGINAL IFR
STRATUS ON THE HEELS OF THE STORMS. EXPECT THIS TO PERSIST AND
COMBINE WITH FOG RESULTING IN WIDESPREAD IFR CONDITIONS OVERNIGHT
THROUGH MID WEDNESDAY MORNING AS THE UPSTREAM SURFACE LOW DEVELOPS
INTO NORTHERN LOWER MICHIGAN. SHOWERS WILL INCREASE COVERAGE AS
CEILING AND VISIBILITY IMPROVE WEDNESDAY AFTERNOON AS THE LOW
PRESSURE SYSTEM MOVES SLOWLY NORTHEAST.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING AOB 5000 FT TONIGHT THROUGH WEDNESDAY
MORNING.

* LOW CONFIDENCE IN CEILING AOB 200 FT/VISIBILITY 1/2SM.

&&

.PREV DISCUSSION...ISSUED 318 PM EDT TUE AUG 19 2014

SHORT TERM...

WITH MLCAPES APPROACHING 2000 J/KG OVER PARTS OF THE CWA NOW THAT
THE BOUNDARY LAYER HAS RECOVERED FROM MORNING CONVECTION...EXPECT
WIDESPREAD SHOWERS AND THUNDERSTORMS TO OVERSPREAD SOUTHEAST
MICHIGAN DURING THE REST OF THE AFTERNOON INTO THIS EVENING. THIS
ACTIVITY WILL SHIFT SOUTHEAST WITH TIME AS AN APPROACHING COLD
FRONT SHIFTS INTO THE REGION.

GIVEN THE DEGREE OF INSTABILITY...AND MODEST DEEP LAYER SHEAR IN
THE NEIGHBORHOOD OF 25-30 KNOTS...SOME OF THESE STORMS WILL MOST
LIKELY BECOME SEVERE. THE BOUNDARY LAYER WILL BE WELL MIXED AS
STORMS MOVE INTO THE AREA...SO DAMAGING WIND GUSTS WILL BE
POSSIBLE WITH THE STRONGEST STORMS.

HEAVY RAINFALL BE A BIGGER CONCERN AS PRECIPITABLE WATER
INCREASES TO 1.75-2.00 INCHES WITHIN BEST PLUME OF DEEP MOISTURE
FUNNELING NORTHEAST INTO AREA IN ADVANCE OF APPROACHING COLD
FRONT/UPPER TROUGH AXIS. AS ADDITIONAL CONVECTION RIDES NORTHEAST
INTO AREA WITH APPROACHING DISTURBANCE OVER NORTHWEST
INDIANA...THE COVERAGE OF HEAVY RAINFALL WILL INCREASE AND FOCUS
GENERALLY SOUTH OF I 69...AND ESPECIALLY BETWEEN THE M 59 AND I 94
CORRIDORS.

A SEVERE THUNDERSTORM WATCH WILL CONTINUE FROM THE M 59 COUNTIES
SOUTHWARD WITH A FLASH FLOOD WATCH CENTERED ON THE METRO DETROIT
AREA AS RUNOFF IN THE URBAN AREAS IS ENHANCED. A BULK OF THIS
ACTIVITY WILL SHIFT SOUTH AND EAST OF THE AREA THIS EVENING...BUT
LINGERING SCATTERED SHOWERS OR A FEW STORMS WILL REMAIN POSSIBLE.

LONG TERM...

THE AREA ACTUALLY TRANSITIONS INTO A MORE SUMMERLIKE PATTERN LATE
THIS WEEK INTO THE WEEKEND AS THE AN UPPER RIDGE EXPANDS INTO THE
EASTERN CONUS. THIS RIDGE ACTUALLY PERSISTS INTO EARLY NEXT WEEK
BEFORE SETTLING SOUTHEAST. THIS PATTERN WILL BRING AN EXTENDED
PERIOD OF WARMER WEATHER WITH TEMPERATURES WELL INTO THE 80S FROM
LATE THIS WEEK ON THROUGH THE REMAINDER OF THE LONG TERM FORECAST
PERIOD. IN FACT...90 DEGREE READINGS WILL BE POSSIBLE AT TIMES.

THIS BUILDING HEAT AND HUMIDITY WILL ALSO BRING PERIODIC SHOWERS
AND THUNDERSTORMS...PARTICULARLY DURING THE COURSE OF THIS WEEK AS
THE TRANSITION IN THE UPPER LEVEL PATTERN OCCURS AND SHORTWAVE
DISTURBANCES RIDE ALONG THE NORTH AND NORTHEAST EDGE OF THIS
FEATURE AS IT EXPANDS INTO THE GREAT LAKES.

MARINE...

SHOWERS AND THUNDERSTORMS WILL EXPAND OVER THE AREA INTO THIS
EVENING AS LOW PRESSURE PUSHES A COLD FRONT INTO THE REGION. THIS
LOW WILL SLOWLY WOBBLE THROUGH THE AREA THROUGH THE MIDDLE OF THE
WEEK AND MAINTAIN PERIODS OF SHOWERS AND THUNDERSTORMS.

IN GENERAL...HOWEVER...WIND AND WAVE CONDITIONS...OUTSIDE OF
THUNDERSTORMS...WILL REMAIN IN CHECK THIS WEEK AS UPPER RIDING
BUILDS INTO THE AREA.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

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


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











000
FXUS63 KDTX 200227
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1027 PM EDT TUE AUG 19 2014

.UPDATE...

THE EARLIER UPDATE MAINTAINED A CHANCE OF SHOWERS AND STORMS AND
ADDED FOG TO THE FORECAST FOR OVERNIGHT THROUGH MID WEDNESDAY
MORNING. THE COOL AND MOIST BOUNDARY LAYER IS PRIMED FOR FOG
DEVELOPMENT OVER THE TOP OF WET GROUND. LATE EVENING OBSERVATIONS
INDICATE MOSTLY A 1 TO 3 DEGREE SURFACE TEMP/DEWPOINT SPREAD
SUGGESTING FOG WILL DEVELOP QUICKLY UNDER ANY OPEN SKY. THE TIMING
AND EXTENT OF CLEARING IS THE MORE CHALLENGING QUESTION. SO
FAR...WEAK GRADIENT FLOW HAS LED TO STRATUS FORMATION IN THE
SAGINAW VALLEY WHERE MID AND HIGH CLOUDS HAVE PARTIALLY CLEARED
AWAY. AT THE SAME TIME...HOURLY MESOANALYSIS AND MODEL SOUNDINGS
INDICATE ENOUGH ELEVATED INSTABILITY LINGERING UNDER THE UPPER LOW
TO MAINTAIN AREAS OF MID TO HIGH CLOUDS AND SCATTERED COVERAGE OF
SHOWERS...AT LEAST FOR A WHILE. EXPECT THE SAGINAW VALLEY STRATUS TO
BUILD TOWARD THE SURFACE DURING THE NIGHT AND MORE OF AN INITIAL
FOG FORMATION IN THE DTW AREA AS GRADIENT FLOW WEAKENS IN ALL
AREAS AND AS HIGH CLOUDS DIMINISH LATER ON...BUT LOW CONFIDENCE
IN THE CLOUD TRENDS PREVENTS A MENTION OF DENSE FOG FOR NOW.

&&

.AVIATION...ISSUED 657 PM EDT TUE AUG 19 2014

//DISCUSSION...

THE PRIMARY AREA OF THUNDERSTORMS HAS MOVED EAST OF THE TERMINAL
SITES AT PRESS TIME. SECONDARY DEVELOPMENT WAS NOTED OVER WESTERN
LOWER MICHIGAN BUT THIS IS NOT EXPECTED TO ATTAIN THE COVERAGE OF
ROUND 1 AND WILL BE HANDLED WITH EVENING UPDATES SHOULD ANY ACTIVITY
SURVIVE THE LOSS OF DAYTIME HEATING WHILE MOVING INTO SE MICHIGAN.
OBSERVATIONS ALSO INDICATE INCREASING COVERAGE OF MVFR/MARGINAL IFR
STRATUS ON THE HEELS OF THE STORMS. EXPECT THIS TO PERSIST AND
COMBINE WITH FOG RESULTING IN WIDESPREAD IFR CONDITIONS OVERNIGHT
THROUGH MID WEDNESDAY MORNING AS THE UPSTREAM SURFACE LOW DEVELOPS
INTO NORTHERN LOWER MICHIGAN. SHOWERS WILL INCREASE COVERAGE AS
CEILING AND VISIBILITY IMPROVE WEDNESDAY AFTERNOON AS THE LOW
PRESSURE SYSTEM MOVES SLOWLY NORTHEAST.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING AOB 5000 FT TONIGHT THROUGH WEDNESDAY
MORNING.

* LOW CONFIDENCE IN CEILING AOB 200 FT/VISIBILITY 1/2SM.

&&

.PREV DISCUSSION...ISSUED 318 PM EDT TUE AUG 19 2014

SHORT TERM...

WITH MLCAPES APPROACHING 2000 J/KG OVER PARTS OF THE CWA NOW THAT
THE BOUNDARY LAYER HAS RECOVERED FROM MORNING CONVECTION...EXPECT
WIDESPREAD SHOWERS AND THUNDERSTORMS TO OVERSPREAD SOUTHEAST
MICHIGAN DURING THE REST OF THE AFTERNOON INTO THIS EVENING. THIS
ACTIVITY WILL SHIFT SOUTHEAST WITH TIME AS AN APPROACHING COLD
FRONT SHIFTS INTO THE REGION.

GIVEN THE DEGREE OF INSTABILITY...AND MODEST DEEP LAYER SHEAR IN
THE NEIGHBORHOOD OF 25-30 KNOTS...SOME OF THESE STORMS WILL MOST
LIKELY BECOME SEVERE. THE BOUNDARY LAYER WILL BE WELL MIXED AS
STORMS MOVE INTO THE AREA...SO DAMAGING WIND GUSTS WILL BE
POSSIBLE WITH THE STRONGEST STORMS.

HEAVY RAINFALL BE A BIGGER CONCERN AS PRECIPITABLE WATER
INCREASES TO 1.75-2.00 INCHES WITHIN BEST PLUME OF DEEP MOISTURE
FUNNELING NORTHEAST INTO AREA IN ADVANCE OF APPROACHING COLD
FRONT/UPPER TROUGH AXIS. AS ADDITIONAL CONVECTION RIDES NORTHEAST
INTO AREA WITH APPROACHING DISTURBANCE OVER NORTHWEST
INDIANA...THE COVERAGE OF HEAVY RAINFALL WILL INCREASE AND FOCUS
GENERALLY SOUTH OF I 69...AND ESPECIALLY BETWEEN THE M 59 AND I 94
CORRIDORS.

A SEVERE THUNDERSTORM WATCH WILL CONTINUE FROM THE M 59 COUNTIES
SOUTHWARD WITH A FLASH FLOOD WATCH CENTERED ON THE METRO DETROIT
AREA AS RUNOFF IN THE URBAN AREAS IS ENHANCED. A BULK OF THIS
ACTIVITY WILL SHIFT SOUTH AND EAST OF THE AREA THIS EVENING...BUT
LINGERING SCATTERED SHOWERS OR A FEW STORMS WILL REMAIN POSSIBLE.

LONG TERM...

THE AREA ACTUALLY TRANSITIONS INTO A MORE SUMMERLIKE PATTERN LATE
THIS WEEK INTO THE WEEKEND AS THE AN UPPER RIDGE EXPANDS INTO THE
EASTERN CONUS. THIS RIDGE ACTUALLY PERSISTS INTO EARLY NEXT WEEK
BEFORE SETTLING SOUTHEAST. THIS PATTERN WILL BRING AN EXTENDED
PERIOD OF WARMER WEATHER WITH TEMPERATURES WELL INTO THE 80S FROM
LATE THIS WEEK ON THROUGH THE REMAINDER OF THE LONG TERM FORECAST
PERIOD. IN FACT...90 DEGREE READINGS WILL BE POSSIBLE AT TIMES.

THIS BUILDING HEAT AND HUMIDITY WILL ALSO BRING PERIODIC SHOWERS
AND THUNDERSTORMS...PARTICULARLY DURING THE COURSE OF THIS WEEK AS
THE TRANSITION IN THE UPPER LEVEL PATTERN OCCURS AND SHORTWAVE
DISTURBANCES RIDE ALONG THE NORTH AND NORTHEAST EDGE OF THIS
FEATURE AS IT EXPANDS INTO THE GREAT LAKES.

MARINE...

SHOWERS AND THUNDERSTORMS WILL EXPAND OVER THE AREA INTO THIS
EVENING AS LOW PRESSURE PUSHES A COLD FRONT INTO THE REGION. THIS
LOW WILL SLOWLY WOBBLE THROUGH THE AREA THROUGH THE MIDDLE OF THE
WEEK AND MAINTAIN PERIODS OF SHOWERS AND THUNDERSTORMS.

IN GENERAL...HOWEVER...WIND AND WAVE CONDITIONS...OUTSIDE OF
THUNDERSTORMS...WILL REMAIN IN CHECK THIS WEEK AS UPPER RIDING
BUILDS INTO THE AREA.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

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


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










000
FXUS63 KDTX 192257
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
657 PM EDT TUE AUG 19 2014

.AVIATION...

//DISCUSSION...

THE PRIMARY AREA OF THUNDERSTORMS HAS MOVED EAST OF THE TERMINAL
SITES AT PRESS TIME. SECONDARY DEVELOPMENT WAS NOTED OVER WESTERN
LOWER MICHIGAN BUT THIS IS NOT EXPECTED TO ATTAIN THE COVERAGE OF
ROUND 1 AND WILL BE HANDLED WITH EVENING UPDATES SHOULD ANY ACTIVITY
SURVIVE THE LOSS OF DAYTIME HEATING WHILE MOVING INTO SE MICHIGAN.
OBSERVATIONS ALSO INDICATE INCREASING COVERAGE OF MVFR/MARGINAL IFR
STRATUS ON THE HEELS OF THE STORMS. EXPECT THIS TO PERSIST AND
COMBINE WITH FOG RESULTING IN WIDESPREAD IFR CONDITIONS OVERNIGHT
THROUGH MID WEDNESDAY MORNING AS THE UPSTREAM SURFACE LOW DEVELOPS
INTO NORTHERN LOWER MICHIGAN. SHOWERS WILL INCREASE COVERAGE AS
CEILING AND VISIBILITY IMPROVE WEDNESDAY AFTERNOON AS THE LOW
PRESSURE SYSTEM MOVES SLOWLY NORTHEAST.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING AOB 5000 FT TONIGHT THROUGH WEDNESDAY
MORNING.

* LOW CONFIDENCE IN CEILING AOB 200 FT/VISIBILITY 1/2SM.

&&

.PREV DISCUSSION...ISSUED 318 PM EDT TUE AUG 19 2014

SHORT TERM...

WITH MLCAPES APPROACHING 2000 J/KG OVER PARTS OF THE CWA NOW THAT
THE BOUNDARY LAYER HAS RECOVERED FROM MORNING CONVECTION...EXPECT
WIDESPREAD SHOWERS AND THUNDERSTORMS TO OVERSPREAD SOUTHEAST
MICHIGAN DURING THE REST OF THE AFTERNOON INTO THIS EVENING. THIS
ACTIVITY WILL SHIFT SOUTHEAST WITH TIME AS AN APPROACHING COLD
FRONT SHIFTS INTO THE REGION.

GIVEN THE DEGREE OF INSTABILITY...AND MODEST DEEP LAYER SHEAR IN
THE NEIGHBORHOOD OF 25-30 KNOTS...SOME OF THESE STORMS WILL MOST
LIKELY BECOME SEVERE. THE BOUNDARY LAYER WILL BE WELL MIXED AS
STORMS MOVE INTO THE AREA...SO DAMAGING WIND GUSTS WILL BE
POSSIBLE WITH THE STRONGEST STORMS.

HEAVY RAINFALL BE A BIGGER CONCERN AS PRECIPITABLE WATER
INCREASES TO 1.75-2.00 INCHES WITHIN BEST PLUME OF DEEP MOISTURE
FUNNELING NORTHEAST INTO AREA IN ADVANCE OF APPROACHING COLD
FRONT/UPPER TROUGH AXIS. AS ADDITIONAL CONVECTION RIDES NORTHEAST
INTO AREA WITH APPROACHING DISTURBANCE OVER NORTHWEST
INDIANA...THE COVERAGE OF HEAVY RAINFALL WILL INCREASE AND FOCUS
GENERALLY SOUTH OF I 69...AND ESPECIALLY BETWEEN THE M 59 AND I 94
CORRIDORS.

A SEVERE THUNDERSTORM WATCH WILL CONTINUE FROM THE M 59 COUNTIES
SOUTHWARD WITH A FLASH FLOOD WATCH CENTERED ON THE METRO DETROIT
AREA AS RUNOFF IN THE URBAN AREAS IS ENHANCED. A BULK OF THIS
ACTIVITY WILL SHIFT SOUTH AND EAST OF THE AREA THIS EVENING...BUT
LINGERING SCATTERED SHOWERS OR A FEW STORMS WILL REMAIN POSSIBLE.

LONG TERM...

THE AREA ACTUALLY TRANSITIONS INTO A MORE SUMMERLIKE PATTERN LATE
THIS WEEK INTO THE WEEKEND AS THE AN UPPER RIDGE EXPANDS INTO THE
EASTERN CONUS. THIS RIDGE ACTUALLY PERSISTS INTO EARLY NEXT WEEK
BEFORE SETTLING SOUTHEAST. THIS PATTERN WILL BRING AN EXTENDED
PERIOD OF WARMER WEATHER WITH TEMPERATURES WELL INTO THE 80S FROM
LATE THIS WEEK ON THROUGH THE REMAINDER OF THE LONG TERM FORECAST
PERIOD. IN FACT...90 DEGREE READINGS WILL BE POSSIBLE AT TIMES.

THIS BUILDING HEAT AND HUMIDITY WILL ALSO BRING PERIODIC SHOWERS
AND THUNDERSTORMS...PARTICULARLY DURING THE COURSE OF THIS WEEK AS
THE TRANSITION IN THE UPPER LEVEL PATTERN OCCURS AND SHORTWAVE
DISTURBANCES RIDE ALONG THE NORTH AND NORTHEAST EDGE OF THIS
FEATURE AS IT EXPANDS INTO THE GREAT LAKES.

MARINE...

SHOWERS AND THUNDERSTORMS WILL EXPAND OVER THE AREA INTO THIS
EVENING AS LOW PRESSURE PUSHES A COLD FRONT INTO THE REGION. THIS
LOW WILL SLOWLY WOBBLE THROUGH THE AREA THROUGH THE MIDDLE OF THE
WEEK AND MAINTAIN PERIODS OF SHOWERS AND THUNDERSTORMS.

IN GENERAL...HOWEVER...WIND AND WAVE CONDITIONS...OUTSIDE OF
THUNDERSTORMS...WILL REMAIN IN CHECK THIS WEEK AS UPPER RIDING
BUILDS INTO THE AREA.

&&

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

&&

$$

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


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









000
FXUS63 KDTX 191918
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
318 PM EDT TUE AUG 19 2014

.SHORT TERM...

WITH MLCAPES APPROACHING 2000 J/KG OVER PARTS OF THE CWA NOW THAT
THE BOUNDARY LAYER HAS RECOVERED FROM MORNING CONVECTION...EXPECT
WIDESPREAD SHOWERS AND THUNDERSTORMS TO OVERSPREAD SOUTHEAST
MICHIGAN DURING THE REST OF THE AFTERNOON INTO THIS EVENING. THIS
ACTIVITY WILL SHIFT SOUTHEAST WITH TIME AS AN APPROACHING COLD
FRONT SHIFTS INTO THE REGION.

GIVEN THE DEGREE OF INSTABILITY...AND MODEST DEEP LAYER SHEAR IN
THE NEIGHBORHOOD OF 25-30 KNOTS...SOME OF THESE STORMS WILL MOST
LIKELY BECOME SEVERE. THE BOUNDARY LAYER WILL BE WELL MIXED AS
STORMS MOVE INTO THE AREA...SO DAMAGING WIND GUSTS WILL BE
POSSIBLE WITH THE STRONGEST STORMS.

HEAVY RAINFALL BE A BIGGER CONCERN AS PRECIPITABLE WATER
INCREASES TO 1.75-2.00 INCHES WITHIN BEST PLUME OF DEEP MOISTURE
FUNNELING NORTHEAST INTO AREA IN ADVANCE OF APPROACHING COLD
FRONT/UPPER TROUGH AXIS. AS ADDITIONAL CONVECTION RIDES NORTHEAST
INTO AREA WITH APPROACHING DISTURBANCE OVER NORTHWEST
INDIANA...THE COVERAGE OF HEAVY RAINFALL WILL INCREASE AND FOCUS
GENERALLY SOUTH OF I 69...AND ESPECIALLY BETWEEN THE M 59 AND I 94
CORRIDORS.

A SEVERE THUNDERSTORM WATCH WILL CONTINUE FROM THE M 59 COUNTIES
SOUTHWARD WITH A FLASH FLOOD WATCH CENTERED ON THE METRO DETROIT
AREA AS RUNOFF IN THE URBAN AREAS IS ENHANCED. A BULK OF THIS
ACTIVITY WILL SHIFT SOUTH AND EAST OF THE AREA THIS EVENING...BUT
LINGERING SCATTERED SHOWERS OR A FEW STORMS WILL REMAIN POSSIBLE.

&&

.LONG TERM...

THE AREA ACTUALLY TRANSITIONS INTO A MORE SUMMERLIKE PATTERN LATE
THIS WEEK INTO THE WEEKEND AS THE AN UPPER RIDGE EXPANDS INTO THE
EASTERN CONUS. THIS RIDGE ACTUALLY PERSISTS INTO EARLY NEXT WEEK
BEFORE SETTLING SOUTHEAST. THIS PATTERN WILL BRING AN EXTENDED
PERIOD OF WARMER WEATHER WITH TEMPERATURES WELL INTO THE 80S FROM
LATE THIS WEEK ON THROUGH THE REMAINDER OF THE LONG TERM FORECAST
PERIOD. IN FACT...90 DEGREE READINGS WILL BE POSSIBLE AT TIMES.

THIS BUILDING HEAT AND HUMIDITY WILL ALSO BRING PERIODIC SHOWERS
AND THUNDERSTORMS...PARTICULARLY DURING THE COURSE OF THIS WEEK AS
THE TRANSITION IN THE UPPER LEVEL PATTERN OCCURS AND SHORTWAVE
DISTURBANCES RIDE ALONG THE NORTH AND NORTHEAST EDGE OF THIS
FEATURE AS IT EXPANDS INTO THE GREAT LAKES.

&&


.MARINE...

SHOWERS AND THUNDERSTORMS WILL EXPAND OVER THE AREA INTO THIS
EVENING AS LOW PRESSURE PUSHES A COLD FRONT INTO THE REGION. THIS
LOW WILL SLOWLY WOBBLE THROUGH THE AREA THROUGH THE MIDDLE OF THE
WEEK AND MAINTAIN PERIODS OF SHOWERS AND THUNDERSTORMS.

IN GENERAL...HOWEVER...WIND AND WAVE CONDITIONS...OUTSIDE OF
THUNDERSTORMS...WILL REMAIN IN CHECK THIS WEEK AS UPPER RIDING
BUILDS INTO THE AREA.

&&

.AVIATION...ISSUED 133 PM EDT TUE AUG 19 2014

//DISCUSSION...
ONGOING DEVELOPING THUNDERSTORM COMPLEX OVER WEST MICHIGAN
STRETCHING SOUTHWEST INTO NORTHERN ILLINOIS WILL WILL SLOWLY ADVANCE
EAST ACROSS THE SOUTHEAST MICHIGAN TERMINAL THROUGH THE MID TO LATE
AFTERNOON HOURS. SOME MINOR ACTIVITY HAS BEEN AFFECTING MBS AND WILL
CONTINUE TO DO SO FOR THE FIRST COUPLE HOURS OF THE FORECAST WINDOW.
WINDS WILL GUST TOWARD 20KTS IN THE WARM SECTOR AHEAD OF THE LINE OF
STORMS. ENOUGH LOW-LEVEL MOISTURE WILL HAVE THE OPPORTUNITY TO BE
TRAPPED BENEATH THE NOCTURNAL INVERSION TONIGHT TO AT LEAST GET SOME
LIGHT FOG OVERNIGHT.  MOISTURE WILL LIFT INTO A DIURNAL CLOUD FIELD
DURING THE DAYLIGHT HOURS ON WEDNESDAY.

FOR DTW...THUNDERSTORMS WILL SETTLE IN LATE THIS AFTERNOON AND
EVENING...MAINLY IN THE 22-01Z TIME PERIOD. EXPECTATIONS ARE FOR
GUSTS TOWARD 20KTS FROM THE WEST WITH THE LINE AS IT PINCHES IN ON
THE TERMINAL. LIGHT FOG SHOULD DEVELOP OVERNIGHT.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE OF CEILINGS AOB 5000 FT PERIODICALLY THROUGH
  WEDNESDAY MORNING.

* HIGH CONFIDENCE IN THUNDERSTORMS THIS AFTERNOON AND THIS
  EVENING...MEDIUM CONFIDENCE IN TIMING.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...FLASH FLOOD WATCH...MIZ069-MIZ070-MIZ075-MIZ076...UNTIL 10 PM
     TUESDAY.

LAKE HURON...NONE.

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

&&

$$

SHORT TERM...DG
LONG TERM....DG
MARINE.......DG
AVIATION.....MANN


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








000
FXUS63 KDTX 191734
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
133 PM EDT TUE AUG 19 2014

.AVIATION...

//DISCUSSION...
ONGOING DEVELOPING THUNDERSTORM COMPLEX OVER WEST MICHIGAN
STRETCHING SOUTHWEST INTO NORTHERN ILLINOIS WILL WILL SLOWLY ADVANCE
EAST ACROSS THE SOUTHEAST MICHIGAN TERMINAL THROUGH THE MID TO LATE
AFTERNOON HOURS. SOME MINOR ACTIVITY HAS BEEN AFFECTING MBS AND WILL
CONTINUE TO DO SO FOR THE FIRST COUPLE HOURS OF THE FORECAST WINDOW.
WINDS WILL GUST TOWARD 20KTS IN THE WARM SECTOR AHEAD OF THE LINE OF
STORMS. ENOUGH LOW-LEVEL MOISTURE WILL HAVE THE OPPORTUNITY TO BE
TRAPPED BENEATH THE NOCTURNAL INVERSION TONIGHT TO AT LEAST GET SOME
LIGHT FOG OVERNIGHT.  MOISTURE WILL LIFT INTO A DIURNAL CLOUD FIELD
DURING THE DAYLIGHT HOURS ON WEDNESDAY.

FOR DTW...THUNDERSTORMS WILL SETTLE IN LATE THIS AFTERNOON AND
EVENING...MAINLY IN THE 22-01Z TIME PERIOD. EXPECTATIONS ARE FOR
GUSTS TOWARD 20KTS FROM THE WEST WITH THE LINE AS IT PINCHES IN ON
THE TERMINAL. LIGHT FOG SHOULD DEVELOP OVERNIGHT.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE OF CEILINGS AOB 5000 FT PERIODICALLY THROUGH
  WEDNESDAY MORNING.

* HIGH CONFIDENCE IN THUNDERSTORMS THIS AFTERNOON AND THIS
  EVENING...MEDIUM CONFIDENCE IN TIMING.

* MEDIUM CONFIDENCE IN FOG REDUCING VISIBILITY BELOW 3SM OVERNIGHT.

&&

.UPDATE...ISSUED AT 1249 PM EDT TUE AUG 19 2014

MORNING CONVECTION DISSIPATED AS WEAK MCS OUTRAN LOW LEVEL JET
SUPPORT TO THE WEST. SUBSIDENCE IN THE WAKE OF THIS SYSTEM HAS LED
BE SIGNIFICANT CLEARING OVER LARGE PARTS OF LOWER MICHIGAN WITH
RAPID AIRMASS RECOVERY EVIDENCE IN SURFACE OBS/VISIBLE SATELLITE
IMAGERY OVER SOUTHWEST LOWER MICHIGAN. MID LEVEL FGEN HAS ALREADY
FORCED ANOTHER SIGNIFICANT BAND OF CONVECTION FROM THE SAGINAW
VALLEY WEST AND SOUTHWEST TO GRAND RAPIDS.

A MATURE MCS IS ALSO TRACKING QUICKLY ACROSS ILLINOIS AND FORCING
FROM THIS APPROACHING COMPLEX WILL LIKELY AID IN THE DEVELOPMENT
OF ADDITIONAL THUNDERSTORMS ALONG CONVERGENCE TO THE LEE OF LAKE
MICHIGAN OVER SOUTHWEST LOWER MICHIGAN EARLY THIS AFTERNOON. THIS
WILL EVENTUALLY LEAD TO A FAIRLY SOLID LINE OF STORMS...WHICH WILL
BUILD INTO SOUTHEAST LOWER MICHIGAN.

GIVEN THE DEGREE OF INSTABILITY...MLCAPE AROUND 2000 J/KG...EXPECTED
AS AIRMASS RECOVERY CONTINUES AND MODEST DEEP LAYER SHEAR IN THE
NEIGHBORHOOD OF 30 KNOTS...SOME OF THESE STORMS WILL MOST LIKELY
BECOME SEVERE. THE BOUNDARY LAYER WILL BE WELL MIXED AS STORMS
MOVE INTO THE AREA...SO DAMAGING WIND GUSTS WILL BE POSSIBLE WITH
THE STRONGEST STORMS AND LARGE HAIL WILL ALSO BE POSSIBLE GIVEN
UPDRAFT STRENGTH EXPECTED AS CAPE READINGS TOP 2000 J/KG OVER THE
SOUTHERN PORTION OF THE CWA.

HEAVY RAINFALL WILL ALSO BE A CONCERN AS PRECIPITABLE WATER
INCREASES TO 1.75-2.00 INCHES WITHIN BEST PLUME OF DEEP MOISTURE
FUNNELING NORTHEAST INTO AREA IN ADVANCE OF APPROACHING COLD
FRONT/UPPER TROUGH AXIS.

&&

.PREV DISCUSSION...ISSUED 433 AM EDT TUE AUG 19 2014

A LOW PRESSURE SYSTEM CURRENTLY OVER NORTHERN WISCONSIN WILL SLOWLY
TRACK EAST OVER NORTHERN LOWER MICHIGAN BY TONIGHT. MOISTURE HAS
SURGED AHEAD OF THIS APPROACHING LOW...AS EVIDENCED BY SURFACE DEW
POINTS IN THE LOWER 60S ACROSS SOUTHEAST MICHIGAN. SHOWERS AND
THUNDERSTORMS ARE ONGOING THIS MORNING ACROSS WESTERN MICHIGAN...IN
ASSOCIATION WITH A LOW LEVEL THETA-E RIDGE SURGING EASTWARD.
ALTHOUGH CURRENT ACTIVITY IS RATHER DIFFUSE...THE FORCING IS THERE
TO CONTINUE A CHANCY POP DURING THE MORNING HOURS.

LATER THIS AFTERNOON ANOTHER LOW LEVEL THETA-E SURGE TRACKS THROUGH
THE STATE AS THE MID LEVEL TROUGH KICKS OUT A SHORTWAVE THAT TRACKS
THROUGH THE CENTRAL GREAT LAKES REGION. THE DYNAMICS WILL HAVE AN
UNSTABLE ATMOSPHERE TO WORK WITH AS MLCAPE VALUES REACH 1000 TO 1500
J/KG...ESPECIALLY ACROSS THE SOUTHERN CWA SOUTH OF M-59. WHILE MODEL
SOUNDINGS SHOW A RATHER WEAK WIND PROFILE...0-6 KM BULK SHEAR VALUES
GET UP TO AROUND 30 KNOTS. THE STORMS THAT MOVE THROUGH DURING THE
AFTERNOON ARE PROGGED TO BE THE STORMS THAT ARE CURRENTLY OVER
WISCONSIN...WHICH AT TIMES HAVE SEVERE. GIVEN THE TIMING...WHICH
WILL BE DURING PEAK HEATING AND THE DYNAMICS THERE IS A SLIGHT
CHANCE SOME OF THESE STORMS COULD BE SEVERE ALONG AND SOUTH OF THE
M-59 CORRIDOR WITH DAMAGING WINDS OF 60 MPH AND TO A LESSER EXTENT
HAIL OF PENNY TO QUARTER SIZE. THE ENVIRONMENT WILL BE RICH WITH
MOISTURE...WITH LONG SKINNY CAPE PROFILES AND PWAT VALUES OF 1.5 TO
1.8 INCHES. THIS COUPLED WITH THE EXPECTED SLOW STORM MOTION AROUND
20 MPH WILL ONCE AGAIN BRING THE THREAT FOR FLOODING TO SOUTHEAST
MICHIGAN DURING THE AFTERNOON AND EVENING HOURS.

AS THE MAIN FORCING HEADS EAST PRECIPITATION CHANCES WILL BE ON THE
DOWNWARD TREND DURING THE OVERNIGHT HOURS...WITH LINGERING SHOWERS
AND A FEW THUNDERSTORMS BEHIND THE MAIN FORCING AS A COLD FRONT
UNDERGOES OCCLUSION OVER THE CENTRAL GREAT LAKES. WITH THE LOSS OF
DAYTIME HEATING AND THE MAIN FORCING OFF TO THE EAST THE POTENTIAL
FOR SEVERE WEATHER IS NOT EXPECTED TO LAST MUCH INTO THE EVENING
HOURS.

LONG TERM...

THE MIDWEEK PERIOD IS A DIFFICULT FORECAST WITH THE SLOW MOVING LOW
PRESSURE SYSTEM PASSING THROUGH. TIMING OF PRECIPITATION REMAINS AN
ARDUOUS TASK WITH HIGH DEPENDENCE ON PRIOR CONVECTIVE EVOLUTION.

THE DIFFUSE INNER CYCLONIC SWIRL OF THE UPPER LEVEL LOW WILL DESCEND
SOUTHEASTWARD DIRECTLY INTO LOWER MICHIGAN ON WEDNESDAY. THE CENTER
OF THE BROAD CYCLONIC CIRCULATION IS EXPECTED TO CENTER OVER FAR
NORTHERN LOWER MICHIGAN BETWEEN 18-00Z. THIS PLACES THE CWA IN A
MORE FAVORABLE AREA FOR PRECIPITATION AND HIGH MOISTURE CONTENT BY
REMAINING IN THE SOUTHWESTERLY FLOW/LOWER RIGHT QUADRANT OF THE
CIRCULATION. MODEL EQUIVALENT POTENTIAL TEMPERATURE FIELDS KEEP DEEP
MOISTURE IN PLACE AT LEAST THROUGH 21Z BEFORE A STRAIGHT WESTERLY
WIND PROFILE BEGINS TO BUDGE IN. OVERALL...FRONTAL FORCING IS WEAK
GIVEN THE HOMOGENIZED AND BAROTROPIC SYSTEM. WITH THE HUMID
AIRMASS...NOT EXPECTING THERE TO BE MUCH CAPPING BY THE TIME THE
AFTERNOON HITS. A BAND OF VORTICITY WITH AN ORIENTATION FROM NW TO
SE IS SHOWN TO LIFT INTO THE CWA...BRINGING THE BEST DEEP
CONVERGENCE SIGNAL OVER THE NORTHERN 2/3RDS OF THE CWA (PORT HURON
TO THE SAGINAW VALLEY AND THUMB). POP DISTRIBUTION IS LIKELY FOR
THAT AREA TAPERING DOWN TO A CHANCE ACROSS THE SOUTHWEST. BETTER
HEIGHT GRADIENT AND WIND CORE PUSHES INTO THE SOUTHERN CWA DURING
THE LATE AFTERNOON...LIKELY COLLOCATED WITH SOME DRIER MIDLEVEL AIR.
0-6KM BULK SHEAR VALUES ARE FORECASTED TO INCREASE UPWARDS OF 30
KNOTS WITH THIS FEATURE. IN ADDITION...THE DRIER AIR COULD LEAD TO
SOME STEEPER MIDLEVEL LAPSE RATES THAT COULD CONTRIBUTE TO
RELATIVELY HIGHER CAPE VALUES. MODELS DIFFER BUT THE NAM MAX IS
ADVERTISING ML/SB CAPES OF OVER 2000 J/KG. GIVEN SOME OF THE CWA IS
UNDER A SLIGHT RISK IN SWODY1...SEE NO REASON WHY THERE WILL NOT BE
A SEE TEXT OR SLIGHT RISK DESIGNATION FOR WEDNESDAY. A
UNIDIRECTIONAL WIND PROFILE SUPPORTS ANY LINE SEGMENTS THAT DO
BECOME ORTHOGONAL TO THE MEAN WIND WILL CARRY A HIGHER WINDGUST
THREAT. AN ADDITIONAL THREAT TO MONITOR IS HEAVY RAIN POTENTIAL DUE
TO A SLOW STORM MOTION OF ROUGHLY 25 TO 30 MPH.

DRIER LOWER TROPOSPHERIC AIR AND THE LONGWAVE RIDGE AXIS WILL
FINALLY CATCH SOUTHEASTERN MICHIGAN ON THURSDAY. THIS IS EXPECTED TO
LEAD TO QUIET WEATHER WEDNESDAY NIGHT AND THROUGH THE FIRST HALF OF
THURSDAY. VIRTUALLY NO SURFACE RIDGING TO SPEAK OF AND A
REESTABLISHMENT OF THE UPPER LEVEL RIDGE TO OUR NORTH AND EAST WILL
ALLOW WARM AIR ADVECTION TO FLOOD TO THE NORTHEAST. THIS IS ACTUALLY
EXPECTED TO OCCUR RATHER RAPIDLY. IN STARK CONTRAST TO WHAT USUALLY
OCCURS DURING THE SPRINGTIME. AS A RESULT...MOISTURE/INSTABILITY AND
WARM AIR ADVECTION WILL RETURN RATHER QUICKLY AGAIN BY THURSDAY
AFTERNOON AND FRIDAY. BRING A MID CHANCE POPS IN THURSDAY AFTERNOON
FOR THE SOUTHWESTERN 1/3RD OF THE CWA LINGERING INTO THURSDAY NIGHT.
HUMID CONDITIONS ARE EXPECTED BOTH WEDNESDAY AND THURSDAY.

MARINE...

LIGHT WINDS WILL GIVE WAY TO A MODERATE SOUTHEAST BREEZE TODAY AND
THIS EVENING AS A WEAK LOW DRIFTS TROUGH THE AREA. WINDS WILL BE THE
STRONGEST ACROSS NORTHERN LAKE HURON BUT GUSTS THERE WILL STILL
STRUGGLE TO BREAK 20 KNOTS. THIS LOW WILL ALSO BRING A CHANCE FOR
THUNDERSTORMS BOTH TODAY AND WEDNESDAY...PARTICULARLY FOR THE
SOUTHERN LAKE HURON BASIN AND POINTS SOUTH.

&&

.PREV DISCUSSION...ISSUED 346 AM EDT TUE AUG 19 2014

&&

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

&&

$$

UPDATE.......99
AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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








000
FXUS63 KDTX 191734
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
133 PM EDT TUE AUG 19 2014

.AVIATION...

//DISCUSSION...
ONGOING DEVELOPING THUNDERSTORM COMPLEX OVER WEST MICHIGAN
STRETCHING SOUTHWEST INTO NORTHERN ILLINOIS WILL WILL SLOWLY ADVANCE
EAST ACROSS THE SOUTHEAST MICHIGAN TERMINAL THROUGH THE MID TO LATE
AFTERNOON HOURS. SOME MINOR ACTIVITY HAS BEEN AFFECTING MBS AND WILL
CONTINUE TO DO SO FOR THE FIRST COUPLE HOURS OF THE FORECAST WINDOW.
WINDS WILL GUST TOWARD 20KTS IN THE WARM SECTOR AHEAD OF THE LINE OF
STORMS. ENOUGH LOW-LEVEL MOISTURE WILL HAVE THE OPPORTUNITY TO BE
TRAPPED BENEATH THE NOCTURNAL INVERSION TONIGHT TO AT LEAST GET SOME
LIGHT FOG OVERNIGHT.  MOISTURE WILL LIFT INTO A DIURNAL CLOUD FIELD
DURING THE DAYLIGHT HOURS ON WEDNESDAY.

FOR DTW...THUNDERSTORMS WILL SETTLE IN LATE THIS AFTERNOON AND
EVENING...MAINLY IN THE 22-01Z TIME PERIOD. EXPECTATIONS ARE FOR
GUSTS TOWARD 20KTS FROM THE WEST WITH THE LINE AS IT PINCHES IN ON
THE TERMINAL. LIGHT FOG SHOULD DEVELOP OVERNIGHT.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE OF CEILINGS AOB 5000 FT PERIODICALLY THROUGH
  WEDNESDAY MORNING.

* HIGH CONFIDENCE IN THUNDERSTORMS THIS AFTERNOON AND THIS
  EVENING...MEDIUM CONFIDENCE IN TIMING.

* MEDIUM CONFIDENCE IN FOG REDUCING VISIBILITY BELOW 3SM OVERNIGHT.

&&

.UPDATE...ISSUED AT 1249 PM EDT TUE AUG 19 2014

MORNING CONVECTION DISSIPATED AS WEAK MCS OUTRAN LOW LEVEL JET
SUPPORT TO THE WEST. SUBSIDENCE IN THE WAKE OF THIS SYSTEM HAS LED
BE SIGNIFICANT CLEARING OVER LARGE PARTS OF LOWER MICHIGAN WITH
RAPID AIRMASS RECOVERY EVIDENCE IN SURFACE OBS/VISIBLE SATELLITE
IMAGERY OVER SOUTHWEST LOWER MICHIGAN. MID LEVEL FGEN HAS ALREADY
FORCED ANOTHER SIGNIFICANT BAND OF CONVECTION FROM THE SAGINAW
VALLEY WEST AND SOUTHWEST TO GRAND RAPIDS.

A MATURE MCS IS ALSO TRACKING QUICKLY ACROSS ILLINOIS AND FORCING
FROM THIS APPROACHING COMPLEX WILL LIKELY AID IN THE DEVELOPMENT
OF ADDITIONAL THUNDERSTORMS ALONG CONVERGENCE TO THE LEE OF LAKE
MICHIGAN OVER SOUTHWEST LOWER MICHIGAN EARLY THIS AFTERNOON. THIS
WILL EVENTUALLY LEAD TO A FAIRLY SOLID LINE OF STORMS...WHICH WILL
BUILD INTO SOUTHEAST LOWER MICHIGAN.

GIVEN THE DEGREE OF INSTABILITY...MLCAPE AROUND 2000 J/KG...EXPECTED
AS AIRMASS RECOVERY CONTINUES AND MODEST DEEP LAYER SHEAR IN THE
NEIGHBORHOOD OF 30 KNOTS...SOME OF THESE STORMS WILL MOST LIKELY
BECOME SEVERE. THE BOUNDARY LAYER WILL BE WELL MIXED AS STORMS
MOVE INTO THE AREA...SO DAMAGING WIND GUSTS WILL BE POSSIBLE WITH
THE STRONGEST STORMS AND LARGE HAIL WILL ALSO BE POSSIBLE GIVEN
UPDRAFT STRENGTH EXPECTED AS CAPE READINGS TOP 2000 J/KG OVER THE
SOUTHERN PORTION OF THE CWA.

HEAVY RAINFALL WILL ALSO BE A CONCERN AS PRECIPITABLE WATER
INCREASES TO 1.75-2.00 INCHES WITHIN BEST PLUME OF DEEP MOISTURE
FUNNELING NORTHEAST INTO AREA IN ADVANCE OF APPROACHING COLD
FRONT/UPPER TROUGH AXIS.

&&

.PREV DISCUSSION...ISSUED 433 AM EDT TUE AUG 19 2014

A LOW PRESSURE SYSTEM CURRENTLY OVER NORTHERN WISCONSIN WILL SLOWLY
TRACK EAST OVER NORTHERN LOWER MICHIGAN BY TONIGHT. MOISTURE HAS
SURGED AHEAD OF THIS APPROACHING LOW...AS EVIDENCED BY SURFACE DEW
POINTS IN THE LOWER 60S ACROSS SOUTHEAST MICHIGAN. SHOWERS AND
THUNDERSTORMS ARE ONGOING THIS MORNING ACROSS WESTERN MICHIGAN...IN
ASSOCIATION WITH A LOW LEVEL THETA-E RIDGE SURGING EASTWARD.
ALTHOUGH CURRENT ACTIVITY IS RATHER DIFFUSE...THE FORCING IS THERE
TO CONTINUE A CHANCY POP DURING THE MORNING HOURS.

LATER THIS AFTERNOON ANOTHER LOW LEVEL THETA-E SURGE TRACKS THROUGH
THE STATE AS THE MID LEVEL TROUGH KICKS OUT A SHORTWAVE THAT TRACKS
THROUGH THE CENTRAL GREAT LAKES REGION. THE DYNAMICS WILL HAVE AN
UNSTABLE ATMOSPHERE TO WORK WITH AS MLCAPE VALUES REACH 1000 TO 1500
J/KG...ESPECIALLY ACROSS THE SOUTHERN CWA SOUTH OF M-59. WHILE MODEL
SOUNDINGS SHOW A RATHER WEAK WIND PROFILE...0-6 KM BULK SHEAR VALUES
GET UP TO AROUND 30 KNOTS. THE STORMS THAT MOVE THROUGH DURING THE
AFTERNOON ARE PROGGED TO BE THE STORMS THAT ARE CURRENTLY OVER
WISCONSIN...WHICH AT TIMES HAVE SEVERE. GIVEN THE TIMING...WHICH
WILL BE DURING PEAK HEATING AND THE DYNAMICS THERE IS A SLIGHT
CHANCE SOME OF THESE STORMS COULD BE SEVERE ALONG AND SOUTH OF THE
M-59 CORRIDOR WITH DAMAGING WINDS OF 60 MPH AND TO A LESSER EXTENT
HAIL OF PENNY TO QUARTER SIZE. THE ENVIRONMENT WILL BE RICH WITH
MOISTURE...WITH LONG SKINNY CAPE PROFILES AND PWAT VALUES OF 1.5 TO
1.8 INCHES. THIS COUPLED WITH THE EXPECTED SLOW STORM MOTION AROUND
20 MPH WILL ONCE AGAIN BRING THE THREAT FOR FLOODING TO SOUTHEAST
MICHIGAN DURING THE AFTERNOON AND EVENING HOURS.

AS THE MAIN FORCING HEADS EAST PRECIPITATION CHANCES WILL BE ON THE
DOWNWARD TREND DURING THE OVERNIGHT HOURS...WITH LINGERING SHOWERS
AND A FEW THUNDERSTORMS BEHIND THE MAIN FORCING AS A COLD FRONT
UNDERGOES OCCLUSION OVER THE CENTRAL GREAT LAKES. WITH THE LOSS OF
DAYTIME HEATING AND THE MAIN FORCING OFF TO THE EAST THE POTENTIAL
FOR SEVERE WEATHER IS NOT EXPECTED TO LAST MUCH INTO THE EVENING
HOURS.

LONG TERM...

THE MIDWEEK PERIOD IS A DIFFICULT FORECAST WITH THE SLOW MOVING LOW
PRESSURE SYSTEM PASSING THROUGH. TIMING OF PRECIPITATION REMAINS AN
ARDUOUS TASK WITH HIGH DEPENDENCE ON PRIOR CONVECTIVE EVOLUTION.

THE DIFFUSE INNER CYCLONIC SWIRL OF THE UPPER LEVEL LOW WILL DESCEND
SOUTHEASTWARD DIRECTLY INTO LOWER MICHIGAN ON WEDNESDAY. THE CENTER
OF THE BROAD CYCLONIC CIRCULATION IS EXPECTED TO CENTER OVER FAR
NORTHERN LOWER MICHIGAN BETWEEN 18-00Z. THIS PLACES THE CWA IN A
MORE FAVORABLE AREA FOR PRECIPITATION AND HIGH MOISTURE CONTENT BY
REMAINING IN THE SOUTHWESTERLY FLOW/LOWER RIGHT QUADRANT OF THE
CIRCULATION. MODEL EQUIVALENT POTENTIAL TEMPERATURE FIELDS KEEP DEEP
MOISTURE IN PLACE AT LEAST THROUGH 21Z BEFORE A STRAIGHT WESTERLY
WIND PROFILE BEGINS TO BUDGE IN. OVERALL...FRONTAL FORCING IS WEAK
GIVEN THE HOMOGENIZED AND BAROTROPIC SYSTEM. WITH THE HUMID
AIRMASS...NOT EXPECTING THERE TO BE MUCH CAPPING BY THE TIME THE
AFTERNOON HITS. A BAND OF VORTICITY WITH AN ORIENTATION FROM NW TO
SE IS SHOWN TO LIFT INTO THE CWA...BRINGING THE BEST DEEP
CONVERGENCE SIGNAL OVER THE NORTHERN 2/3RDS OF THE CWA (PORT HURON
TO THE SAGINAW VALLEY AND THUMB). POP DISTRIBUTION IS LIKELY FOR
THAT AREA TAPERING DOWN TO A CHANCE ACROSS THE SOUTHWEST. BETTER
HEIGHT GRADIENT AND WIND CORE PUSHES INTO THE SOUTHERN CWA DURING
THE LATE AFTERNOON...LIKELY COLLOCATED WITH SOME DRIER MIDLEVEL AIR.
0-6KM BULK SHEAR VALUES ARE FORECASTED TO INCREASE UPWARDS OF 30
KNOTS WITH THIS FEATURE. IN ADDITION...THE DRIER AIR COULD LEAD TO
SOME STEEPER MIDLEVEL LAPSE RATES THAT COULD CONTRIBUTE TO
RELATIVELY HIGHER CAPE VALUES. MODELS DIFFER BUT THE NAM MAX IS
ADVERTISING ML/SB CAPES OF OVER 2000 J/KG. GIVEN SOME OF THE CWA IS
UNDER A SLIGHT RISK IN SWODY1...SEE NO REASON WHY THERE WILL NOT BE
A SEE TEXT OR SLIGHT RISK DESIGNATION FOR WEDNESDAY. A
UNIDIRECTIONAL WIND PROFILE SUPPORTS ANY LINE SEGMENTS THAT DO
BECOME ORTHOGONAL TO THE MEAN WIND WILL CARRY A HIGHER WINDGUST
THREAT. AN ADDITIONAL THREAT TO MONITOR IS HEAVY RAIN POTENTIAL DUE
TO A SLOW STORM MOTION OF ROUGHLY 25 TO 30 MPH.

DRIER LOWER TROPOSPHERIC AIR AND THE LONGWAVE RIDGE AXIS WILL
FINALLY CATCH SOUTHEASTERN MICHIGAN ON THURSDAY. THIS IS EXPECTED TO
LEAD TO QUIET WEATHER WEDNESDAY NIGHT AND THROUGH THE FIRST HALF OF
THURSDAY. VIRTUALLY NO SURFACE RIDGING TO SPEAK OF AND A
REESTABLISHMENT OF THE UPPER LEVEL RIDGE TO OUR NORTH AND EAST WILL
ALLOW WARM AIR ADVECTION TO FLOOD TO THE NORTHEAST. THIS IS ACTUALLY
EXPECTED TO OCCUR RATHER RAPIDLY. IN STARK CONTRAST TO WHAT USUALLY
OCCURS DURING THE SPRINGTIME. AS A RESULT...MOISTURE/INSTABILITY AND
WARM AIR ADVECTION WILL RETURN RATHER QUICKLY AGAIN BY THURSDAY
AFTERNOON AND FRIDAY. BRING A MID CHANCE POPS IN THURSDAY AFTERNOON
FOR THE SOUTHWESTERN 1/3RD OF THE CWA LINGERING INTO THURSDAY NIGHT.
HUMID CONDITIONS ARE EXPECTED BOTH WEDNESDAY AND THURSDAY.

MARINE...

LIGHT WINDS WILL GIVE WAY TO A MODERATE SOUTHEAST BREEZE TODAY AND
THIS EVENING AS A WEAK LOW DRIFTS TROUGH THE AREA. WINDS WILL BE THE
STRONGEST ACROSS NORTHERN LAKE HURON BUT GUSTS THERE WILL STILL
STRUGGLE TO BREAK 20 KNOTS. THIS LOW WILL ALSO BRING A CHANCE FOR
THUNDERSTORMS BOTH TODAY AND WEDNESDAY...PARTICULARLY FOR THE
SOUTHERN LAKE HURON BASIN AND POINTS SOUTH.

&&

.PREV DISCUSSION...ISSUED 346 AM EDT TUE AUG 19 2014

&&

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

&&

$$

UPDATE.......99
AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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







000
FXUS63 KDTX 191649
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1249 PM EDT TUE AUG 19 2014

.UPDATE...

MORNING CONVECTION DISSIPATED AS WEAK MCS OUTRAN LOW LEVEL JET
SUPPORT TO THE WEST. SUBSIDENCE IN THE WAKE OF THIS SYSTEM HAS LED
BE SIGNIFICANT CLEARING OVER LARGE PARTS OF LOWER MICHIGAN WITH
RAPID AIRMASS RECOVERY EVIDENCE IN SURFACE OBS/VISIBLE SATELLITE
IMAGERY OVER SOUTHWEST LOWER MICHIGAN. MID LEVEL FGEN HAS ALREADY
FORCED ANOTHER SIGNIFICANT BAND OF CONVECTION FROM THE SAGINAW
VALLEY WEST AND SOUTHWEST TO GRAND RAPIDS.

A MATURE MCS IS ALSO TRACKING QUICKLY ACROSS ILLINOIS AND FORCING
FROM THIS APPROACHING COMPLEX WILL LIKELY AID IN THE DEVELOPMENT
OF ADDITIONAL THUNDERSTORMS ALONG COVERGENCE TO THE LEE OF LAKE
MICHIGAN OVER SOUTHWEST LOWER MICHIGAN EARLY THIS AFTERNOON. THIS
WILL EVENTUALLY LEAD TO A FAIRLY SOLID LINE OF STORMS...WHICH WILL
BUILD INTO SOUTHEAST LOWER MICHIGAN.

GIVEN THE DEGREE OF INSTABILITY...MLCAPE AROUND 2000 J/KG...EXPECTED
AS AIRMASS RECOVERY CONTINUES AND MODEST DEEP LAYER SHEAR IN THE
NEIGHBORHOOD OF 30 KNOTS...SOME OF THESE STORMS WILL MOST LIKELY
BECOME SEVERE. THE BOUNDARY LAYER WILL BE WELL MIXED AS STORMS
MOVE INTO THE AREA...SO DAMAGING WIND GUSTS WILL BE POSSIBLE WITH
THE STRONGEST STORMS AND LARGE HAIL WILL ALSO BE POSSIBLE GIVEN
UPDRAFT STRENGTH EXPECTED AS CAPE READINGS TOP 2000 J/KG OVER THE
SOUTHERN PORTION OF THE CWA.

HEAVY RAINFALL WILL ALSO BE A CONCERN AS PRECIPITABLE WATER
INCREASES TO 1.75-2.00 INCHES WITHIN BEST PLUME OF DEEP MOISURE
FUNNELING NORTHEAST INTO AREA IN ADVANCE OF APPROACHING COLD
FRONT/UPPER TROUGH AXIS.

&&

.AVIATION...ISSUED 705 AM EDT TUE AUG 19 2014

//DISCUSSION...

AN APPROACHING LOW PRESSURE SYSTEM WILL BRING SHOWERS AND
THUNDERSTORMS TO THE TAF SITES TODAY AS MOISTURE AND INSTABILITY
STEADILY INCREASE...MAINLY DURING THE AFTERNOON HOURS WITH THE LINE
OF THUNDERSTORMS CURRENTLY TRACKING EAST THROUGH WESTERN MICHIGAN.
THESE STORMS WILL SWEEP THROUGH FROM WEST TO EAST...WITH
THUNDERSTORM TIMING FAIRLY ON TRACK FROM THE PREVIOUS SET OF TAFS
ACCORDING TO THE HI-RES MODEL RUNS. THEREFORE WILL NOT CHANCE MUCH
FROM THE PREVIOUS SET IN THIS REGARD. OVERNIGHT SOME FOG IS POSSIBLE
BEHIND THE COLD FRONT. WILL INTRODUCE SOME IFR VSBYS AND MVFR CIGS
OVERNIGHT WITH THIS SET GIVEN THE MOISTURE THE RAIN SHOWERS WILL
BRING TODAY.

FOR DTW...THE APPROACH OF THE UPPER LOW AND PEAK AFTERNOON HEATING
WILL PROVIDE A HIGH LIKELIHOOD OF SHOWERS AND THUNDERSTORMS LATE
THIS AFTERNOON AND EVENING...MAINLY IN THE 19-23Z TIME PERIOD.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE OF CEILINGS AOB 5000 FT THROUGH THE TAF PERIOD.

* HIGH CONFIDENCE IN THUNDERSTORMS THIS AFTERNOON AND THIS
  EVENING...MEDIUM CONFIDENCE IN TIMING.

&&

.PREV DISCUSSION...ISSUED 433 AM EDT TUE AUG 19 2014

A LOW PRESSURE SYSTEM CURRENTLY OVER NORTHERN WISCONSIN WILL SLOWLY
TRACK EAST OVER NORTHERN LOWER MICHIGAN BY TONIGHT. MOISTURE HAS
SURGED AHEAD OF THIS APPROACHING LOW...AS EVIDENCED BY SURFACE DEW
POINTS IN THE LOWER 60S ACROSS SOUTHEAST MICHIGAN. SHOWERS AND
THUNDERSTORMS ARE ONGOING THIS MORNING ACROSS WESTERN MICHIGAN...IN
ASSOCIATION WITH A LOW LEVEL THETA-E RIDGE SURGING EASTWARD.
ALTHOUGH CURRENT ACTIVITY IS RATHER DIFFUSE...THE FORCING IS THERE
TO CONTINUE A CHANCY POP DURING THE MORNING HOURS.

LATER THIS AFTERNOON ANOTHER LOW LEVEL THETA-E SURGE TRACKS THROUGH
THE STATE AS THE MID LEVEL TROUGH KICKS OUT A SHORTWAVE THAT TRACKS
THROUGH THE CENTRAL GREAT LAKES REGION. THE DYNAMICS WILL HAVE AN
UNSTABLE ATMOSPHERE TO WORK WITH AS MLCAPE VALUES REACH 1000 TO 1500
J/KG...ESPECIALLY ACROSS THE SOUTHERN CWA SOUTH OF M-59. WHILE MODEL
SOUNDINGS SHOW A RATHER WEAK WIND PROFILE...0-6 KM BULK SHEAR VALUES
GET UP TO AROUND 30 KNOTS. THE STORMS THAT MOVE THROUGH DURING THE
AFTERNOON ARE PROGGED TO BE THE STORMS THAT ARE CURRENTLY OVER
WISCONSIN...WHICH AT TIMES HAVE SEVERE. GIVEN THE TIMING...WHICH
WILL BE DURING PEAK HEATING AND THE DYNAMICS THERE IS A SLIGHT
CHANCE SOME OF THESE STORMS COULD BE SEVERE ALONG AND SOUTH OF THE
M-59 CORRIDOR WITH DAMAGING WINDS OF 60 MPH AND TO A LESSER EXTENT
HAIL OF PENNY TO QUARTER SIZE. THE ENVIRONMENT WILL BE RICH WITH
MOISTURE...WITH LONG SKINNY CAPE PROFILES AND PWAT VALUES OF 1.5 TO
1.8 INCHES. THIS COUPLED WITH THE EXPECTED SLOW STORM MOTION AROUND
20 MPH WILL ONCE AGAIN BRING THE THREAT FOR FLOODING TO SOUTHEAST
MICHIGAN DURING THE AFTERNOON AND EVENING HOURS.

AS THE MAIN FORCING HEADS EAST PRECIPITATION CHANCES WILL BE ON THE
DOWNWARD TREND DURING THE OVERNIGHT HOURS...WITH LINGERING SHOWERS
AND A FEW THUNDERSTORMS BEHIND THE MAIN FORCING AS A COLD FRONT
UNDERGOES OCCLUSION OVER THE CENTRAL GREAT LAKES. WITH THE LOSS OF
DAYTIME HEATING AND THE MAIN FORCING OFF TO THE EAST THE POTENTIAL
FOR SEVERE WEATHER IS NOT EXPECTED TO LAST MUCH INTO THE EVENING
HOURS.

LONG TERM...

THE MIDWEEK PERIOD IS A DIFFICULT FORECAST WITH THE SLOW MOVING LOW
PRESSURE SYSTEM PASSING THROUGH. TIMING OF PRECIPITATION REMAINS AN
ARDUOUS TASK WITH HIGH DEPENDENCE ON PRIOR CONVECTIVE EVOLUTION.

THE DIFFUSE INNER CYCLONIC SWIRL OF THE UPPER LEVEL LOW WILL DESCEND
SOUTHEASTWARD DIRECTLY INTO LOWER MICHIGAN ON WEDNESDAY. THE CENTER
OF THE BROAD CYCLONIC CIRCULATION IS EXPECTED TO CENTER OVER FAR
NORTHERN LOWER MICHIGAN BETWEEN 18-00Z. THIS PLACES THE CWA IN A
MORE FAVORABLE AREA FOR PRECIPITATION AND HIGH MOISTURE CONTENT BY
REMAINING IN THE SOUTHWESTERLY FLOW/LOWER RIGHT QUADRANT OF THE
CIRCULATION. MODEL EQUIVALENT POTENTIAL TEMPERATURE FIELDS KEEP DEEP
MOISTURE IN PLACE AT LEAST THROUGH 21Z BEFORE A STRAIGHT WESTERLY
WIND PROFILE BEGINS TO BUDGE IN. OVERALL...FRONTAL FORCING IS WEAK
GIVEN THE HOMOGENIZED AND BAROTROPIC SYSTEM. WITH THE HUMID
AIRMASS...NOT EXPECTING THERE TO BE MUCH CAPPING BY THE TIME THE
AFTERNOON HITS. A BAND OF VORTICITY WITH AN ORIENTATION FROM NW TO
SE IS SHOWN TO LIFT INTO THE CWA...BRINGING THE BEST DEEP
CONVERGENCE SIGNAL OVER THE NORTHERN 2/3RDS OF THE CWA (PORT HURON
TO THE SAGINAW VALLEY AND THUMB). POP DISTRIBUTION IS LIKELY FOR
THAT AREA TAPERING DOWN TO A CHANCE ACROSS THE SOUTHWEST. BETTER
HEIGHT GRADIENT AND WIND CORE PUSHES INTO THE SOUTHERN CWA DURING
THE LATE AFTERNOON...LIKELY COLLOCATED WITH SOME DRIER MIDLEVEL AIR.
0-6KM BULK SHEAR VALUES ARE FORECASTED TO INCREASE UPWARDS OF 30
KNOTS WITH THIS FEATURE. IN ADDITION...THE DRIER AIR COULD LEAD TO
SOME STEEPER MIDLEVEL LAPSE RATES THAT COULD CONTRIBUTE TO
RELATIVELY HIGHER CAPE VALUES. MODELS DIFFER BUT THE NAM MAX IS
ADVERTISING ML/SB CAPES OF OVER 2000 J/KG. GIVEN SOME OF THE CWA IS
UNDER A SLIGHT RISK IN SWODY1...SEE NO REASON WHY THERE WILL NOT BE
A SEE TEXT OR SLIGHT RISK DESIGNATION FOR WEDNESDAY. A
UNIDIRECTIONAL WIND PROFILE SUPPORTS ANY LINE SEGMENTS THAT DO
BECOME ORTHOGONAL TO THE MEAN WIND WILL CARRY A HIGHER WINDGUST
THREAT. AN ADDITIONAL THREAT TO MONITOR IS HEAVY RAIN POTENTIAL DUE
TO A SLOW STORM MOTION OF ROUGHLY 25 TO 30 MPH.

DRIER LOWER TROPOSPHERIC AIR AND THE LONGWAVE RIDGE AXIS WILL
FINALLY CATCH SOUTHEASTERN MICHIGAN ON THURSDAY. THIS IS EXPECTED TO
LEAD TO QUIET WEATHER WEDNESDAY NIGHT AND THROUGH THE FIRST HALF OF
THURSDAY. VIRTUALLY NO SURFACE RIDGING TO SPEAK OF AND A
REESTABLISHMENT OF THE UPPER LEVEL RIDGE TO OUR NORTH AND EAST WILL
ALLOW WARM AIR ADVECTION TO FLOOD TO THE NORTHEAST. THIS IS ACTUALLY
EXPECTED TO OCCUR RATHER RAPIDLY. IN STARK CONTRAST TO WHAT USUALLY
OCCURS DURING THE SPRINGTIME. AS A RESULT...MOISTURE/INSTABILITY AND
WARM AIR ADVECTION WILL RETURN RATHER QUICKLY AGAIN BY THURSDAY
AFTERNOON AND FRIDAY. BRING A MID CHANCE POPS IN THURSDAY AFTERNOON
FOR THE SOUTHWESTERN 1/3RD OF THE CWA LINGERING INTO THURSDAY NIGHT.
HUMID CONDITIONS ARE EXPECTED BOTH WEDNESDAY AND THURSDAY.

MARINE...

LIGHT WINDS WILL GIVE WAY TO A MODERATE SOUTHEAST BREEZE TODAY AND
THIS EVENING AS A WEAK LOW DRIFTS TROUGH THE AREA. WINDS WILL BE THE
STRONGEST ACROSS NORTHERN LAKE HURON BUT GUSTS THERE WILL STILL
STRUGGLE TO BREAK 20 KNOTS. THIS LOW WILL ALSO BRING A CHANCE FOR
THUNDERSTORMS BOTH TODAY AND WEDNESDAY...PARTICULARLY FOR THE
SOUTHERN LAKE HURON BASIN AND POINTS SOUTH.

&&

.PREV DISCUSSION...ISSUED 346 AM EDT TUE AUG 19 2014

&&

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

&&

$$

UPDATE.......99
AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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







000
FXUS63 KDTX 191105
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
705 AM EDT TUE AUG 19 2014


.AVIATION...

//DISCUSSION...

AN APPROACHING LOW PRESSURE SYSTEM WILL BRING SHOWERS AND
THUNDERSTORMS TO THE TAF SITES TODAY AS MOISTURE AND INSTABILITY
STEADILY INCREASE...MAINLY DURING THE AFTERNOON HOURS WITH THE LINE
OF THUNDERSTORMS CURRENTLY TRACKING EAST THROUGH WESTERN MICHIGAN.
THESE STORMS WILL SWEEP THROUGH FROM WEST TO EAST...WITH
THUNDERSTORM TIMING FAIRLY ON TRACK FROM THE PREVIOUS SET OF TAFS
ACCORDING TO THE HI-RES MODEL RUNS. THEREFORE WILL NOT CHANCE MUCH
FROM THE PREVIOUS SET IN THIS REGARD. OVERNIGHT SOME FOG IS POSSIBLE
BEHIND THE COLD FRONT. WILL INTRODUCE SOME IFR VSBYS AND MVFR CIGS
OVERNIGHT WITH THIS SET GIVEN THE MOISTURE THE RAIN SHOWERS WILL
BRING TODAY.

FOR DTW...THE APPROACH OF THE UPPER LOW AND PEAK AFTERNOON HEATING
WILL PROVIDE A HIGH LIKELIHOOD OF SHOWERS AND THUNDERSTORMS LATE
THIS AFTERNOON AND EVENING...MAINLY IN THE 19-23Z TIME PERIOD.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE OF CEILINGS AOB 5000 FT THROUGH THE TAF PERIOD.

* HIGH CONFIDENCE IN THUNDERSTORMS THIS AFTERNOON AND THIS
  EVENING...MEDIUM CONFIDENCE IN TIMING.

&&

.PREV DISCUSSION...ISSUED 433 AM EDT TUE AUG 19 2014


A LOW PRESSURE SYSTEM CURRENTLY OVER NORTHERN WISCONSIN WILL SLOWLY
TRACK EAST OVER NORTHERN LOWER MICHIGAN BY TONIGHT. MOISTURE HAS
SURGED AHEAD OF THIS APPROACHING LOW...AS EVIDENCED BY SURFACE DEW
POINTS IN THE LOWER 60S ACROSS SOUTHEAST MICHIGAN. SHOWERS AND
THUNDERSTORMS ARE ONGOING THIS MORNING ACROSS WESTERN MICHIGAN...IN
ASSOCIATION WITH A LOW LEVEL THETA-E RIDGE SURGING EASTWARD.
ALTHOUGH CURRENT ACTIVITY IS RATHER DIFFUSE...THE FORCING IS THERE
TO CONTINUE A CHANCY POP DURING THE MORNING HOURS.

LATER THIS AFTERNOON ANOTHER LOW LEVEL THETA-E SURGE TRACKS THROUGH
THE STATE AS THE MID LEVEL TROUGH KICKS OUT A SHORTWAVE THAT TRACKS
THROUGH THE CENTRAL GREAT LAKES REGION. THE DYNAMICS WILL HAVE AN
UNSTABLE ATMOSPHERE TO WORK WITH AS MLCAPE VALUES REACH 1000 TO 1500
J/KG...ESPECIALLY ACROSS THE SOUTHERN CWA SOUTH OF M-59. WHILE MODEL
SOUNDINGS SHOW A RATHER WEAK WIND PROFILE...0-6 KM BULK SHEAR VALUES
GET UP TO AROUND 30 KNOTS. THE STORMS THAT MOVE THROUGH DURING THE
AFTERNOON ARE PROGGED TO BE THE STORMS THAT ARE CURRENTLY OVER
WISCONSIN...WHICH AT TIMES HAVE SEVERE. GIVEN THE TIMING...WHICH
WILL BE DURING PEAK HEATING AND THE DYNAMICS THERE IS A SLIGHT
CHANCE SOME OF THESE STORMS COULD BE SEVERE ALONG AND SOUTH OF THE
M-59 CORRIDOR WITH DAMAGING WINDS OF 60 MPH AND TO A LESSER EXTENT
HAIL OF PENNY TO QUARTER SIZE. THE ENVIRONMENT WILL BE RICH WITH
MOISTURE...WITH LONG SKINNY CAPE PROFILES AND PWAT VALUES OF 1.5 TO
1.8 INCHES. THIS COUPLED WITH THE EXPECTED SLOW STORM MOTION AROUND
20 MPH WILL ONCE AGAIN BRING THE THREAT FOR FLOODING TO SOUTHEAST
MICHIGAN DURING THE AFTERNOON AND EVENING HOURS.

AS THE MAIN FORCING HEADS EAST PRECIPITATION CHANCES WILL BE ON THE
DOWNWARD TREND DURING THE OVERNIGHT HOURS...WITH LINGERING SHOWERS
AND A FEW THUNDERSTORMS BEHIND THE MAIN FORCING AS A COLD FRONT
UNDERGOES OCCLUSION OVER THE CENTRAL GREAT LAKES. WITH THE LOSS OF
DAYTIME HEATING AND THE MAIN FORCING OFF TO THE EAST THE POTENTIAL
FOR SEVERE WEATHER IS NOT EXPECTED TO LAST MUCH INTO THE EVENING
HOURS.

LONG TERM...

THE MIDWEEK PERIOD IS A DIFFICULT FORECAST WITH THE SLOW MOVING LOW
PRESSURE SYSTEM PASSING THROUGH. TIMING OF PRECIPITATION REMAINS AN
ARDUOUS TASK WITH HIGH DEPENDENCE ON PRIOR CONVECTIVE EVOLUTION.

THE DIFFUSE INNER CYCLONIC SWIRL OF THE UPPER LEVEL LOW WILL DESCEND
SOUTHEASTWARD DIRECTLY INTO LOWER MICHIGAN ON WEDNESDAY. THE CENTER
OF THE BROAD CYCLONIC CIRCULATION IS EXPECTED TO CENTER OVER FAR
NORTHERN LOWER MICHIGAN BETWEEN 18-00Z. THIS PLACES THE CWA IN A
MORE FAVORABLE AREA FOR PRECIPITATION AND HIGH MOISTURE CONTENT BY
REMAINING IN THE SOUTHWESTERLY FLOW/LOWER RIGHT QUADRANT OF THE
CIRCULATION. MODEL EQUIVALENT POTENTIAL TEMPERATURE FIELDS KEEP DEEP
MOISTURE IN PLACE AT LEAST THROUGH 21Z BEFORE A STRAIGHT WESTERLY
WIND PROFILE BEGINS TO BUDGE IN. OVERALL...FRONTAL FORCING IS WEAK
GIVEN THE HOMOGENIZED AND BAROTROPIC SYSTEM. WITH THE HUMID
AIRMASS...NOT EXPECTING THERE TO BE MUCH CAPPING BY THE TIME THE
AFTERNOON HITS. A BAND OF VORTICITY WITH AN ORIENTATION FROM NW TO
SE IS SHOWN TO LIFT INTO THE CWA...BRINGING THE BEST DEEP
CONVERGENCE SIGNAL OVER THE NORTHERN 2/3RDS OF THE CWA (PORT HURON
TO THE SAGINAW VALLEY AND THUMB). POP DISTRIBUTION IS LIKELY FOR
THAT AREA TAPERING DOWN TO A CHANCE ACROSS THE SOUTHWEST. BETTER
HEIGHT GRADIENT AND WIND CORE PUSHES INTO THE SOUTHERN CWA DURING
THE LATE AFTERNOON...LIKELY COLLOCATED WITH SOME DRIER MIDLEVEL AIR.
0-6KM BULK SHEAR VALUES ARE FORECASTED TO INCREASE UPWARDS OF 30
KNOTS WITH THIS FEATURE. IN ADDITION...THE DRIER AIR COULD LEAD TO
SOME STEEPER MIDLEVEL LAPSE RATES THAT COULD CONTRIBUTE TO
RELATIVELY HIGHER CAPE VALUES. MODELS DIFFER BUT THE NAM MAX IS
ADVERTISING ML/SB CAPES OF OVER 2000 J/KG. GIVEN SOME OF THE CWA IS
UNDER A SLIGHT RISK IN SWODY1...SEE NO REASON WHY THERE WILL NOT BE
A SEE TEXT OR SLIGHT RISK DESIGNATION FOR WEDNESDAY. A
UNIDIRECTIONAL WIND PROFILE SUPPORTS ANY LINE SEGMENTS THAT DO
BECOME ORTHOGONAL TO THE MEAN WIND WILL CARRY A HIGHER WINDGUST
THREAT. AN ADDITIONAL THREAT TO MONITOR IS HEAVY RAIN POTENTIAL DUE
TO A SLOW STORM MOTION OF ROUGHLY 25 TO 30 MPH.

DRIER LOWER TROPOSPHERIC AIR AND THE LONGWAVE RIDGE AXIS WILL
FINALLY CATCH SOUTHEASTERN MICHIGAN ON THURSDAY. THIS IS EXPECTED TO
LEAD TO QUIET WEATHER WEDNESDAY NIGHT AND THROUGH THE FIRST HALF OF
THURSDAY. VIRTUALLY NO SURFACE RIDGING TO SPEAK OF AND A
REESTABLISHMENT OF THE UPPER LEVEL RIDGE TO OUR NORTH AND EAST WILL
ALLOW WARM AIR ADVECTION TO FLOOD TO THE NORTHEAST. THIS IS ACTUALLY
EXPECTED TO OCCUR RATHER RAPIDLY. IN STARK CONTRAST TO WHAT USUALLY
OCCURS DURING THE SPRINGTIME. AS A RESULT...MOISTURE/INSTABILITY AND
WARM AIR ADVECTION WILL RETURN RATHER QUICKLY AGAIN BY THURSDAY
AFTERNOON AND FRIDAY. BRING A MID CHANCE POPS IN THURSDAY AFTERNOON
FOR THE SOUTHWESTERN 1/3RD OF THE CWA LINGERING INTO THURSDAY NIGHT.
HUMID CONDITIONS ARE EXPECTED BOTH WEDNESDAY AND THURSDAY.

MARINE...

LIGHT WINDS WILL GIVE WAY TO A MODERATE SOUTHEAST BREEZE TODAY AND
THIS EVENING AS A WEAK LOW DRIFTS TROUGH THE AREA. WINDS WILL BE THE
STRONGEST ACROSS NORTHERN LAKE HURON BUT GUSTS THERE WILL STILL
STRUGGLE TO BREAK 20 KNOTS. THIS LOW WILL ALSO BRING A CHANCE FOR
THUNDERSTORMS BOTH TODAY AND WEDNESDAY...PARTICULARLY FOR THE
SOUTHERN LAKE HURON BASIN AND POINTS SOUTH.

PREV DISCUSSION...ISSUED 346 AM EDT TUE AUG 19 2014

&&

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

&&

$$

AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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








000
FXUS63 KDTX 191105
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
705 AM EDT TUE AUG 19 2014


.AVIATION...

//DISCUSSION...

AN APPROACHING LOW PRESSURE SYSTEM WILL BRING SHOWERS AND
THUNDERSTORMS TO THE TAF SITES TODAY AS MOISTURE AND INSTABILITY
STEADILY INCREASE...MAINLY DURING THE AFTERNOON HOURS WITH THE LINE
OF THUNDERSTORMS CURRENTLY TRACKING EAST THROUGH WESTERN MICHIGAN.
THESE STORMS WILL SWEEP THROUGH FROM WEST TO EAST...WITH
THUNDERSTORM TIMING FAIRLY ON TRACK FROM THE PREVIOUS SET OF TAFS
ACCORDING TO THE HI-RES MODEL RUNS. THEREFORE WILL NOT CHANCE MUCH
FROM THE PREVIOUS SET IN THIS REGARD. OVERNIGHT SOME FOG IS POSSIBLE
BEHIND THE COLD FRONT. WILL INTRODUCE SOME IFR VSBYS AND MVFR CIGS
OVERNIGHT WITH THIS SET GIVEN THE MOISTURE THE RAIN SHOWERS WILL
BRING TODAY.

FOR DTW...THE APPROACH OF THE UPPER LOW AND PEAK AFTERNOON HEATING
WILL PROVIDE A HIGH LIKELIHOOD OF SHOWERS AND THUNDERSTORMS LATE
THIS AFTERNOON AND EVENING...MAINLY IN THE 19-23Z TIME PERIOD.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE OF CEILINGS AOB 5000 FT THROUGH THE TAF PERIOD.

* HIGH CONFIDENCE IN THUNDERSTORMS THIS AFTERNOON AND THIS
  EVENING...MEDIUM CONFIDENCE IN TIMING.

&&

.PREV DISCUSSION...ISSUED 433 AM EDT TUE AUG 19 2014


A LOW PRESSURE SYSTEM CURRENTLY OVER NORTHERN WISCONSIN WILL SLOWLY
TRACK EAST OVER NORTHERN LOWER MICHIGAN BY TONIGHT. MOISTURE HAS
SURGED AHEAD OF THIS APPROACHING LOW...AS EVIDENCED BY SURFACE DEW
POINTS IN THE LOWER 60S ACROSS SOUTHEAST MICHIGAN. SHOWERS AND
THUNDERSTORMS ARE ONGOING THIS MORNING ACROSS WESTERN MICHIGAN...IN
ASSOCIATION WITH A LOW LEVEL THETA-E RIDGE SURGING EASTWARD.
ALTHOUGH CURRENT ACTIVITY IS RATHER DIFFUSE...THE FORCING IS THERE
TO CONTINUE A CHANCY POP DURING THE MORNING HOURS.

LATER THIS AFTERNOON ANOTHER LOW LEVEL THETA-E SURGE TRACKS THROUGH
THE STATE AS THE MID LEVEL TROUGH KICKS OUT A SHORTWAVE THAT TRACKS
THROUGH THE CENTRAL GREAT LAKES REGION. THE DYNAMICS WILL HAVE AN
UNSTABLE ATMOSPHERE TO WORK WITH AS MLCAPE VALUES REACH 1000 TO 1500
J/KG...ESPECIALLY ACROSS THE SOUTHERN CWA SOUTH OF M-59. WHILE MODEL
SOUNDINGS SHOW A RATHER WEAK WIND PROFILE...0-6 KM BULK SHEAR VALUES
GET UP TO AROUND 30 KNOTS. THE STORMS THAT MOVE THROUGH DURING THE
AFTERNOON ARE PROGGED TO BE THE STORMS THAT ARE CURRENTLY OVER
WISCONSIN...WHICH AT TIMES HAVE SEVERE. GIVEN THE TIMING...WHICH
WILL BE DURING PEAK HEATING AND THE DYNAMICS THERE IS A SLIGHT
CHANCE SOME OF THESE STORMS COULD BE SEVERE ALONG AND SOUTH OF THE
M-59 CORRIDOR WITH DAMAGING WINDS OF 60 MPH AND TO A LESSER EXTENT
HAIL OF PENNY TO QUARTER SIZE. THE ENVIRONMENT WILL BE RICH WITH
MOISTURE...WITH LONG SKINNY CAPE PROFILES AND PWAT VALUES OF 1.5 TO
1.8 INCHES. THIS COUPLED WITH THE EXPECTED SLOW STORM MOTION AROUND
20 MPH WILL ONCE AGAIN BRING THE THREAT FOR FLOODING TO SOUTHEAST
MICHIGAN DURING THE AFTERNOON AND EVENING HOURS.

AS THE MAIN FORCING HEADS EAST PRECIPITATION CHANCES WILL BE ON THE
DOWNWARD TREND DURING THE OVERNIGHT HOURS...WITH LINGERING SHOWERS
AND A FEW THUNDERSTORMS BEHIND THE MAIN FORCING AS A COLD FRONT
UNDERGOES OCCLUSION OVER THE CENTRAL GREAT LAKES. WITH THE LOSS OF
DAYTIME HEATING AND THE MAIN FORCING OFF TO THE EAST THE POTENTIAL
FOR SEVERE WEATHER IS NOT EXPECTED TO LAST MUCH INTO THE EVENING
HOURS.

LONG TERM...

THE MIDWEEK PERIOD IS A DIFFICULT FORECAST WITH THE SLOW MOVING LOW
PRESSURE SYSTEM PASSING THROUGH. TIMING OF PRECIPITATION REMAINS AN
ARDUOUS TASK WITH HIGH DEPENDENCE ON PRIOR CONVECTIVE EVOLUTION.

THE DIFFUSE INNER CYCLONIC SWIRL OF THE UPPER LEVEL LOW WILL DESCEND
SOUTHEASTWARD DIRECTLY INTO LOWER MICHIGAN ON WEDNESDAY. THE CENTER
OF THE BROAD CYCLONIC CIRCULATION IS EXPECTED TO CENTER OVER FAR
NORTHERN LOWER MICHIGAN BETWEEN 18-00Z. THIS PLACES THE CWA IN A
MORE FAVORABLE AREA FOR PRECIPITATION AND HIGH MOISTURE CONTENT BY
REMAINING IN THE SOUTHWESTERLY FLOW/LOWER RIGHT QUADRANT OF THE
CIRCULATION. MODEL EQUIVALENT POTENTIAL TEMPERATURE FIELDS KEEP DEEP
MOISTURE IN PLACE AT LEAST THROUGH 21Z BEFORE A STRAIGHT WESTERLY
WIND PROFILE BEGINS TO BUDGE IN. OVERALL...FRONTAL FORCING IS WEAK
GIVEN THE HOMOGENIZED AND BAROTROPIC SYSTEM. WITH THE HUMID
AIRMASS...NOT EXPECTING THERE TO BE MUCH CAPPING BY THE TIME THE
AFTERNOON HITS. A BAND OF VORTICITY WITH AN ORIENTATION FROM NW TO
SE IS SHOWN TO LIFT INTO THE CWA...BRINGING THE BEST DEEP
CONVERGENCE SIGNAL OVER THE NORTHERN 2/3RDS OF THE CWA (PORT HURON
TO THE SAGINAW VALLEY AND THUMB). POP DISTRIBUTION IS LIKELY FOR
THAT AREA TAPERING DOWN TO A CHANCE ACROSS THE SOUTHWEST. BETTER
HEIGHT GRADIENT AND WIND CORE PUSHES INTO THE SOUTHERN CWA DURING
THE LATE AFTERNOON...LIKELY COLLOCATED WITH SOME DRIER MIDLEVEL AIR.
0-6KM BULK SHEAR VALUES ARE FORECASTED TO INCREASE UPWARDS OF 30
KNOTS WITH THIS FEATURE. IN ADDITION...THE DRIER AIR COULD LEAD TO
SOME STEEPER MIDLEVEL LAPSE RATES THAT COULD CONTRIBUTE TO
RELATIVELY HIGHER CAPE VALUES. MODELS DIFFER BUT THE NAM MAX IS
ADVERTISING ML/SB CAPES OF OVER 2000 J/KG. GIVEN SOME OF THE CWA IS
UNDER A SLIGHT RISK IN SWODY1...SEE NO REASON WHY THERE WILL NOT BE
A SEE TEXT OR SLIGHT RISK DESIGNATION FOR WEDNESDAY. A
UNIDIRECTIONAL WIND PROFILE SUPPORTS ANY LINE SEGMENTS THAT DO
BECOME ORTHOGONAL TO THE MEAN WIND WILL CARRY A HIGHER WINDGUST
THREAT. AN ADDITIONAL THREAT TO MONITOR IS HEAVY RAIN POTENTIAL DUE
TO A SLOW STORM MOTION OF ROUGHLY 25 TO 30 MPH.

DRIER LOWER TROPOSPHERIC AIR AND THE LONGWAVE RIDGE AXIS WILL
FINALLY CATCH SOUTHEASTERN MICHIGAN ON THURSDAY. THIS IS EXPECTED TO
LEAD TO QUIET WEATHER WEDNESDAY NIGHT AND THROUGH THE FIRST HALF OF
THURSDAY. VIRTUALLY NO SURFACE RIDGING TO SPEAK OF AND A
REESTABLISHMENT OF THE UPPER LEVEL RIDGE TO OUR NORTH AND EAST WILL
ALLOW WARM AIR ADVECTION TO FLOOD TO THE NORTHEAST. THIS IS ACTUALLY
EXPECTED TO OCCUR RATHER RAPIDLY. IN STARK CONTRAST TO WHAT USUALLY
OCCURS DURING THE SPRINGTIME. AS A RESULT...MOISTURE/INSTABILITY AND
WARM AIR ADVECTION WILL RETURN RATHER QUICKLY AGAIN BY THURSDAY
AFTERNOON AND FRIDAY. BRING A MID CHANCE POPS IN THURSDAY AFTERNOON
FOR THE SOUTHWESTERN 1/3RD OF THE CWA LINGERING INTO THURSDAY NIGHT.
HUMID CONDITIONS ARE EXPECTED BOTH WEDNESDAY AND THURSDAY.

MARINE...

LIGHT WINDS WILL GIVE WAY TO A MODERATE SOUTHEAST BREEZE TODAY AND
THIS EVENING AS A WEAK LOW DRIFTS TROUGH THE AREA. WINDS WILL BE THE
STRONGEST ACROSS NORTHERN LAKE HURON BUT GUSTS THERE WILL STILL
STRUGGLE TO BREAK 20 KNOTS. THIS LOW WILL ALSO BRING A CHANCE FOR
THUNDERSTORMS BOTH TODAY AND WEDNESDAY...PARTICULARLY FOR THE
SOUTHERN LAKE HURON BASIN AND POINTS SOUTH.

PREV DISCUSSION...ISSUED 346 AM EDT TUE AUG 19 2014

&&

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

&&

$$

AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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







000
FXUS63 KDTX 190833
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
433 AM EDT TUE AUG 19 2014

.SHORT TERM...TODAY AND TONIGHT

A LOW PRESSURE SYSTEM CURRENTLY OVER NORTHERN WISCONSIN WILL SLOWLY
TRACK EAST OVER NORTHERN LOWER MICHIGAN BY TONIGHT. MOISTURE HAS
SURGED AHEAD OF THIS APPROACHING LOW...AS EVIDENCED BY SURFACE DEW
POINTS IN THE LOWER 60S ACROSS SOUTHEAST MICHIGAN. SHOWERS AND
THUNDERSTORMS ARE ONGOING THIS MORNING ACROSS WESTERN MICHIGAN...IN
ASSOCIATION WITH A LOW LEVEL THETA-E RIDGE SURGING EASTWARD.
ALTHOUGH CURRENT ACTIVITY IS RATHER DIFFUSE...THE FORCING IS THERE
TO CONTINUE A CHANCY POP DURING THE MORNING HOURS.

LATER THIS AFTERNOON ANOTHER LOW LEVEL THETA-E SURGE TRACKS THROUGH
THE STATE AS THE MID LEVEL TROUGH KICKS OUT A SHORTWAVE THAT TRACKS
THROUGH THE CENTRAL GREAT LAKES REGION. THE DYNAMICS WILL HAVE AN
UNSTABLE ATMOSPHERE TO WORK WITH AS MLCAPE VALUES REACH 1000 TO 1500
J/KG...ESPECIALLY ACROSS THE SOUTHERN CWA SOUTH OF M-59. WHILE MODEL
SOUNDINGS SHOW A RATHER WEAK WIND PROFILE...0-6 KM BULK SHEAR VALUES
GET UP TO AROUND 30 KNOTS. THE STORMS THAT MOVE THROUGH DURING THE
AFTERNOON ARE PROGGED TO BE THE STORMS THAT ARE CURRENTLY OVER
WISCONSIN...WHICH AT TIMES HAVE SEVERE. GIVEN THE TIMING...WHICH
WILL BE DURING PEAK HEATING AND THE DYNAMICS THERE IS A SLIGHT
CHANCE SOME OF THESE STORMS COULD BE SEVERE ALONG AND SOUTH OF THE
M-59 CORRIDOR WITH DAMAGING WINDS OF 60 MPH AND TO A LESSER EXTENT
HAIL OF PENNY TO QUARTER SIZE. THE ENVIRONMENT WILL BE RICH WITH
MOISTURE...WITH LONG SKINNY CAPE PROFILES AND PWAT VALUES OF 1.5 TO
1.8 INCHES. THIS COUPLED WITH THE EXPECTED SLOW STORM MOTION AROUND
20 MPH WILL ONCE AGAIN BRING THE THREAT FOR FLOODING TO SOUTHEAST
MICHIGAN DURING THE AFTERNOON AND EVENING HOURS.

AS THE MAIN FORCING HEADS EAST PRECIPITATION CHANCES WILL BE ON THE
DOWNWARD TREND DURING THE OVERNIGHT HOURS...WITH LINGERING SHOWERS
AND A FEW THUNDERSTORMS BEHIND THE MAIN FORCING AS A COLD FRONT
UNDERGOES OCCLUSION OVER THE CENTRAL GREAT LAKES. WITH THE LOSS OF
DAYTIME HEATING AND THE MAIN FORCING OFF TO THE EAST THE POTENTIAL
FOR SEVERE WEATHER IS NOT EXPECTED TO LAST MUCH INTO THE EVENING
HOURS.

&&

.LONG TERM...

THE MIDWEEK PERIOD IS A DIFFICULT FORECAST WITH THE SLOW MOVING LOW
PRESSURE SYSTEM PASSING THROUGH. TIMING OF PRECIPITATION REMAINS AN
ARDUOUS TASK WITH HIGH DEPENDENCE ON PRIOR CONVECTIVE EVOLUTION.

THE DIFFUSE INNER CYCLONIC SWIRL OF THE UPPER LEVEL LOW WILL DESCEND
SOUTHEASTWARD DIRECTLY INTO LOWER MICHIGAN ON WEDNESDAY. THE CENTER
OF THE BROAD CYCLONIC CIRCULATION IS EXPECTED TO CENTER OVER FAR
NORTHERN LOWER MICHIGAN BETWEEN 18-00Z. THIS PLACES THE CWA IN A
MORE FAVORABLE AREA FOR PRECIPITATION AND HIGH MOISTURE CONTENT BY
REMAINING IN THE SOUTHWESTERLY FLOW/LOWER RIGHT QUADRANT OF THE
CIRCULATION. MODEL EQUIVALENT POTENTIAL TEMPERATURE FIELDS KEEP DEEP
MOISTURE IN PLACE AT LEAST THROUGH 21Z BEFORE A STRAIGHT WESTERLY
WIND PROFILE BEGINS TO BUDGE IN. OVERALL...FRONTAL FORCING IS WEAK
GIVEN THE HOMOGENIZED AND BAROTROPIC SYSTEM. WITH THE HUMID
AIRMASS...NOT EXPECTING THERE TO BE MUCH CAPPING BY THE TIME THE
AFTERNOON HITS. A BAND OF VORTICITY WITH AN ORIENTATION FROM NW TO
SE IS SHOWN TO LIFT INTO THE CWA...BRINGING THE BEST DEEP
CONVERGENCE SIGNAL OVER THE NORTHERN 2/3RDS OF THE CWA (PORT HURON
TO THE SAGINAW VALLEY AND THUMB). POP DISTRIBUTION IS LIKELY FOR
THAT AREA TAPERING DOWN TO A CHANCE ACROSS THE SOUTHWEST. BETTER
HEIGHT GRADIENT AND WIND CORE PUSHES INTO THE SOUTHERN CWA DURING
THE LATE AFTERNOON...LIKELY COLLOCATED WITH SOME DRIER MIDLEVEL AIR.
0-6KM BULK SHEAR VALUES ARE FORECASTED TO INCREASE UPWARDS OF 30
KNOTS WITH THIS FEATURE. IN ADDITION...THE DRIER AIR COULD LEAD TO
SOME STEEPER MIDLEVEL LAPSE RATES THAT COULD CONTRIBUTE TO
RELATIVELY HIGHER CAPE VALUES. MODELS DIFFER BUT THE NAM MAX IS
ADVERTISING ML/SB CAPES OF OVER 2000 J/KG. GIVEN SOME OF THE CWA IS
UNDER A SLIGHT RISK IN SWODY1...SEE NO REASON WHY THERE WILL NOT BE
A SEE TEXT OR SLIGHT RISK DESIGNATION FOR WEDNESDAY. A
UNIDIRECTIONAL WIND PROFILE SUPPORTS ANY LINE SEGMENTS THAT DO
BECOME ORTHOGONAL TO THE MEAN WIND WILL CARRY A HIGHER WINDGUST
THREAT. AN ADDITIONAL THREAT TO MONITOR IS HEAVY RAIN POTENTIAL DUE
TO A SLOW STORM MOTION OF ROUGHLY 25 TO 30 MPH.

DRIER LOWER TROPOSPHERIC AIR AND THE LONGWAVE RIDGE AXIS WILL
FINALLY CATCH SOUTHEASTERN MICHIGAN ON THURSDAY. THIS IS EXPECTED TO
LEAD TO QUIET WEATHER WEDNESDAY NIGHT AND THROUGH THE FIRST HALF OF
THURSDAY. VIRTUALLY NO SURFACE RIDGING TO SPEAK OF AND A
REESTABLISHMENT OF THE UPPER LEVEL RIDGE TO OUR NORTH AND EAST WILL
ALLOW WARM AIR ADVECTION TO FLOOD TO THE NORTHEAST. THIS IS ACTUALLY
EXPECTED TO OCCUR RATHER RAPIDLY. IN STARK CONTRAST TO WHAT USUALLY
OCCURS DURING THE SPRINGTIME. AS A RESULT...MOISTURE/INSTABILITY AND
WARM AIR ADVECTION WILL RETURN RATHER QUICKLY AGAIN BY THURSDAY
AFTERNOON AND FRIDAY. BRING A MID CHANCE POPS IN THURSDAY AFTERNOON
FOR THE SOUTHWESTERN 1/3RD OF THE CWA LINGERING INTO THURSDAY NIGHT.
HUMID CONDITIONS ARE EXPECTED BOTH WEDNESDAY AND THURSDAY.

&&

.MARINE...

LIGHT WINDS WILL GIVE WAY TO A MODERATE SOUTHEAST BREEZE TODAY AND
THIS EVENING AS A WEAK LOW DRIFTS TROUGH THE AREA. WINDS WILL BE THE
STRONGEST ACROSS NORTHERN LAKE HURON BUT GUSTS THERE WILL STILL
STRUGGLE TO BREAK 20 KNOTS. THIS LOW WILL ALSO BRING A CHANCE FOR
THUNDERSTORMS BOTH TODAY AND WEDNESDAY...PARTICULARLY FOR THE
SOUTHERN LAKE HURON BASIN AND POINTS SOUTH.

&&

.PREV DISCUSSION...ISSUED 346 AM EDT TUE AUG 19 2014


&&

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

&&

$$

SHORT TERM...KURIMSKI
LONG TERM....CB
MARINE.......CB


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







000
FXUS63 KDTX 190746
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
346 AM EDT TUE AUG 19 2014

.SHORT TERM...TODAY AND TONIGHT

A LOW PRESSURE SYSTEM CURRENTLY OVER NORTHERN WISCONSIN WILL SLOWLY
TRACK EAST OVER NORTHERN LOWER MICHIGAN BY TONIGHT. MOISTURE HAS
SURGED AHEAD OF THIS APPROACHING LOW...AS EVIDENCED BY SURFACE DEW
POINTS IN THE LOWER 60S ACROSS SOUTHEAST MICHIGAN. SHOWERS AND
THUNDERSTORMS ARE ONGOING THIS MORNING ACROSS WESTERN MICHIGAN...IN
ASSOCIATION WITH A LOW LEVEL THETA-E RIDGE SURGING EASTWARD.
ALTHOUGH CURRENT ACTIVITY IS RATHER DIFFUSE...THE FORCING IS THERE
TO CONTINUE A CHANCY POP DURING THE MORNING HOURS.

LATER THIS AFTERNOON ANOTHER LOW LEVEL THETA-E SURGE TRACKS THROUGH
THE STATE AS THE MID LEVEL TROUGH KICKS OUT A SHORTWAVE THAT TRACKS
THROUGH THE CENTRAL GREAT LAKES REGION. THE DYNAMICS WILL HAVE AN
UNSTABLE ATMOSPHERE TO WORK WITH AS MLCAPE VALUES REACH 1000 TO 1500
J/KG...ESPECIALLY ACROSS THE SOUTHERN CWA SOUTH OF M-59. WHILE MODEL
SOUNDINGS SHOW A RATHER WEAK WIND PROFILE...0-6 KM BULK SHEAR VALUES
GET UP TO AROUND 30 KNOTS. THE STORMS THAT MOVE THROUGH DURING THE
AFTERNOON ARE PROGGED TO BE THE STORMS THAT ARE CURRENTLY OVER
WISCONSIN...WHICH AT TIMES HAVE SEVERE. GIVEN THE TIMING...WHICH
WILL BE DURING PEAK HEATING AND THE DYNAMICS THERE IS A SLIGHT
CHANCE SOME OF THESE STORMS COULD BE SEVERE ALONG AND SOUTH OF THE
M-59 CORRIDOR WITH DAMAGING WINDS OF 60 MPH AND TO A LESSER EXTENT
HAIL OF PENNY TO QUARTER SIZE.

AS THE MAIN FORCING HEADS EAST PRECIPITATION CHANCES WILL BE ON THE
DOWNWARD TREND DURING THE OVERNIGHT HOURS...WITH LINGERING SHOWERS
AND A FEW THUNDERSTORMS BEHIND THE MAIN FORCING AS A COLD FRONT
UNDERGOES OCCLUSION OVER THE CENTRAL GREAT LAKES. WITH THE LOSS OF
DAYTIME HEATING AND THE MAIN FORCING OFF TO THE EAST THE POTENTIAL
FOR SEVERE WEATHER IS NOT EXPECTED TO LAST MUCH INTO THE EVENING
HOURS.

&&

.LONG TERM...

THE MIDWEEK PERIOD IS A DIFFICULT FORECAST WITH THE SLOW MOVING LOW
PRESSURE SYSTEM PASSING THROUGH. TIMING OF PRECIPITATION REMAINS AN
ARDUOUS TASK WITH HIGH DEPENDENCE ON PRIOR CONVECTIVE EVOLUTION.

THE DIFFUSE INNER CYCLONIC SWIRL OF THE UPPER LEVEL LOW WILL DESCEND
SOUTHEASTWARD DIRECTLY INTO LOWER MICHIGAN ON WEDNESDAY. THE CENTER
OF THE BROAD CYCLONIC CIRCULATION IS EXPECTED TO CENTER OVER FAR
NORTHERN LOWER MICHIGAN BETWEEN 18-00Z. THIS PLACES THE CWA IN A
MORE FAVORABLE AREA FOR PRECIPITATION AND HIGH MOISTURE CONTENT BY
REMAINING IN THE SOUTHWESTERLY FLOW/LOWER RIGHT QUADRANT OF THE
CIRCULATION. MODEL EQUIVALENT POTENTIAL TEMPERATURE FIELDS KEEP DEEP
MOISTURE IN PLACE AT LEAST THROUGH 21Z BEFORE A STRAIGHT WESTERLY
WIND PROFILE BEGINS TO BUDGE IN. OVERALL...FRONTAL FORCING IS WEAK
GIVEN THE HOMOGENIZED AND BAROTROPIC SYSTEM. WITH THE HUMID
AIRMASS...NOT EXPECTING THERE TO BE MUCH CAPPING BY THE TIME THE
AFTERNOON HITS. A BAND OF VORTICITY WITH AN ORIENTATION FROM NW TO
SE IS SHOWN TO LIFT INTO THE CWA...BRINGING THE BEST DEEP
CONVERGENCE SIGNAL OVER THE NORTHERN 2/3RDS OF THE CWA (PORT HURON
TO THE SAGINAW VALLEY AND THUMB). POP DISTRIBUTION IS LIKELY FOR
THAT AREA TAPERING DOWN TO A CHANCE ACROSS THE SOUTHWEST. BETTER
HEIGHT GRADIENT AND WIND CORE PUSHES INTO THE SOUTHERN CWA DURING
THE LATE AFTERNOON...LIKELY COLLOCATED WITH SOME DRIER MIDLEVEL AIR.
0-6KM BULK SHEAR VALUES ARE FORECASTED TO INCREASE UPWARDS OF 30
KNOTS WITH THIS FEATURE. IN ADDITION...THE DRIER AIR COULD LEAD TO
SOME STEEPER MIDLEVEL LAPSE RATES THAT COULD CONTRIBUTE TO
RELATIVELY HIGHER CAPE VALUES. MODELS DIFFER BUT THE NAM MAX IS
ADVERTISING ML/SB CAPES OF OVER 2000 J/KG. GIVEN SOME OF THE CWA IS
UNDER A SLIGHT RISK IN SWODY1...SEE NO REASON WHY THERE WILL NOT BE
A SEE TEXT OR SLIGHT RISK DESIGNATION FOR WEDNESDAY. A
UNIDIRECTIONAL WIND PROFILE SUPPORTS ANY LINE SEGMENTS THAT DO
BECOME ORTHOGONAL TO THE MEAN WIND WILL CARRY A HIGHER WINDGUST
THREAT. AN ADDITIONAL THREAT TO MONITOR IS HEAVY RAIN POTENTIAL DUE
TO A SLOW STORM MOTION OF ROUGHLY 25 TO 30 MPH.

DRIER LOWER TROPOSPHERIC AIR AND THE LONGWAVE RIDGE AXIS WILL
FINALLY CATCH SOUTHEASTERN MICHIGAN ON THURSDAY. THIS IS EXPECTED TO
LEAD TO QUIET WEATHER WEDNESDAY NIGHT AND THROUGH THE FIRST HALF OF
THURSDAY. VIRTUALLY NO SURFACE RIDGING TO SPEAK OF AND A
REESTABLISHMENT OF THE UPPER LEVEL RIDGE TO OUR NORTH AND EAST WILL
ALLOW WARM AIR ADVECTION TO FLOOD TO THE NORTHEAST. THIS IS ACTUALLY
EXPECTED TO OCCUR RATHER RAPIDLY. IN STARK CONTRAST TO WHAT USUALLY
OCCURS DURING THE SPRINGTIME. AS A RESULT...MOISTURE/INSTABILITY AND
WARM AIR ADVECTION WILL RETURN RATHER QUICKLY AGAIN BY THURSDAY
AFTERNOON AND FRIDAY. BRING A MID CHANCE POPS IN THURSDAY AFTERNOON
FOR THE SOUTHWESTERN 1/3RD OF THE CWA LINGERING INTO THURSDAY NIGHT.
HUMID CONDITIONS ARE EXPECTED BOTH WEDNESDAY AND THURSDAY.

&&

.MARINE...

LIGHT WINDS WILL GIVE WAY TO A MODERATE SOUTHEAST BREEZE TODAY AND
THIS EVENING AS A WEAK LOW DRIFTS TROUGH THE AREA. WINDS WILL BE THE
STRONGEST ACROSS NORTHERN LAKE HURON BUT GUSTS THERE WILL STILL
STRUGGLE TO BREAK 20 KNOTS. THIS LOW WILL ALSO BRING A CHANCE FOR
THUNDERSTORMS BOTH TODAY AND WEDNESDAY...PARTICULARLY FOR THE
SOUTHERN LAKE HURON BASIN AND POINTS SOUTH.

&&

.AVIATION...ISSUED 1150 PM EDT MON AUG 18 2014

//DISCUSSION...

LOW LEVEL MOISTURE ADVECTION IS RESULTING IN AN EXPANDING REGION OF
STRATO CU BASED IN THE 3500 TO 4500 FT RANGE. THIS TREND WILL
CONTINUE DURING THE EARLY MORNING HOURS. THE APPROACH OF AN UPPER
LEVEL LOW WILL STEEPEN MID LEVEL LAPSE RATES EARLY THIS
MORNING...PROVIDING AN INCREASED CHANCE FOR SHOWERS. THE BEST
CHANCES EARLY THIS MORNING WILL CONTINUE TO BE AROUND MBS CLOSER TO
THE STRONGER LARGER SCALE SUPPORT. WHILE THERE IS A CHANCE FOR SOME
MORNING THUNDERSTORMS...THE CHANCES REMAIN A BIT TOO LOW TO INCLUDE
IN THE TAFS AT THIS TIME.

FOR DTW...SHOWER AND THUNDERSTORM CHANCES WILL BE A LITTLE LESS
AROUND METRO THIS MORNING AS THE BETTER FORCING WILL RESIDE FARTHER
NORTH. THE APPROACH OF THE UPPER LOW AND PEAK AFTERNOON HEATING WILL
PROVIDE A HIGH LIKELIHOOD OF SHOWERS AND THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE OF CEILINGS AOB 5000 FT THROUGH THE TAF PERIOD.

&&

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

&&

$$

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


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








000
FXUS63 KDTX 190746
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
346 AM EDT TUE AUG 19 2014

.SHORT TERM...TODAY AND TONIGHT

A LOW PRESSURE SYSTEM CURRENTLY OVER NORTHERN WISCONSIN WILL SLOWLY
TRACK EAST OVER NORTHERN LOWER MICHIGAN BY TONIGHT. MOISTURE HAS
SURGED AHEAD OF THIS APPROACHING LOW...AS EVIDENCED BY SURFACE DEW
POINTS IN THE LOWER 60S ACROSS SOUTHEAST MICHIGAN. SHOWERS AND
THUNDERSTORMS ARE ONGOING THIS MORNING ACROSS WESTERN MICHIGAN...IN
ASSOCIATION WITH A LOW LEVEL THETA-E RIDGE SURGING EASTWARD.
ALTHOUGH CURRENT ACTIVITY IS RATHER DIFFUSE...THE FORCING IS THERE
TO CONTINUE A CHANCY POP DURING THE MORNING HOURS.

LATER THIS AFTERNOON ANOTHER LOW LEVEL THETA-E SURGE TRACKS THROUGH
THE STATE AS THE MID LEVEL TROUGH KICKS OUT A SHORTWAVE THAT TRACKS
THROUGH THE CENTRAL GREAT LAKES REGION. THE DYNAMICS WILL HAVE AN
UNSTABLE ATMOSPHERE TO WORK WITH AS MLCAPE VALUES REACH 1000 TO 1500
J/KG...ESPECIALLY ACROSS THE SOUTHERN CWA SOUTH OF M-59. WHILE MODEL
SOUNDINGS SHOW A RATHER WEAK WIND PROFILE...0-6 KM BULK SHEAR VALUES
GET UP TO AROUND 30 KNOTS. THE STORMS THAT MOVE THROUGH DURING THE
AFTERNOON ARE PROGGED TO BE THE STORMS THAT ARE CURRENTLY OVER
WISCONSIN...WHICH AT TIMES HAVE SEVERE. GIVEN THE TIMING...WHICH
WILL BE DURING PEAK HEATING AND THE DYNAMICS THERE IS A SLIGHT
CHANCE SOME OF THESE STORMS COULD BE SEVERE ALONG AND SOUTH OF THE
M-59 CORRIDOR WITH DAMAGING WINDS OF 60 MPH AND TO A LESSER EXTENT
HAIL OF PENNY TO QUARTER SIZE.

AS THE MAIN FORCING HEADS EAST PRECIPITATION CHANCES WILL BE ON THE
DOWNWARD TREND DURING THE OVERNIGHT HOURS...WITH LINGERING SHOWERS
AND A FEW THUNDERSTORMS BEHIND THE MAIN FORCING AS A COLD FRONT
UNDERGOES OCCLUSION OVER THE CENTRAL GREAT LAKES. WITH THE LOSS OF
DAYTIME HEATING AND THE MAIN FORCING OFF TO THE EAST THE POTENTIAL
FOR SEVERE WEATHER IS NOT EXPECTED TO LAST MUCH INTO THE EVENING
HOURS.

&&

.LONG TERM...

THE MIDWEEK PERIOD IS A DIFFICULT FORECAST WITH THE SLOW MOVING LOW
PRESSURE SYSTEM PASSING THROUGH. TIMING OF PRECIPITATION REMAINS AN
ARDUOUS TASK WITH HIGH DEPENDENCE ON PRIOR CONVECTIVE EVOLUTION.

THE DIFFUSE INNER CYCLONIC SWIRL OF THE UPPER LEVEL LOW WILL DESCEND
SOUTHEASTWARD DIRECTLY INTO LOWER MICHIGAN ON WEDNESDAY. THE CENTER
OF THE BROAD CYCLONIC CIRCULATION IS EXPECTED TO CENTER OVER FAR
NORTHERN LOWER MICHIGAN BETWEEN 18-00Z. THIS PLACES THE CWA IN A
MORE FAVORABLE AREA FOR PRECIPITATION AND HIGH MOISTURE CONTENT BY
REMAINING IN THE SOUTHWESTERLY FLOW/LOWER RIGHT QUADRANT OF THE
CIRCULATION. MODEL EQUIVALENT POTENTIAL TEMPERATURE FIELDS KEEP DEEP
MOISTURE IN PLACE AT LEAST THROUGH 21Z BEFORE A STRAIGHT WESTERLY
WIND PROFILE BEGINS TO BUDGE IN. OVERALL...FRONTAL FORCING IS WEAK
GIVEN THE HOMOGENIZED AND BAROTROPIC SYSTEM. WITH THE HUMID
AIRMASS...NOT EXPECTING THERE TO BE MUCH CAPPING BY THE TIME THE
AFTERNOON HITS. A BAND OF VORTICITY WITH AN ORIENTATION FROM NW TO
SE IS SHOWN TO LIFT INTO THE CWA...BRINGING THE BEST DEEP
CONVERGENCE SIGNAL OVER THE NORTHERN 2/3RDS OF THE CWA (PORT HURON
TO THE SAGINAW VALLEY AND THUMB). POP DISTRIBUTION IS LIKELY FOR
THAT AREA TAPERING DOWN TO A CHANCE ACROSS THE SOUTHWEST. BETTER
HEIGHT GRADIENT AND WIND CORE PUSHES INTO THE SOUTHERN CWA DURING
THE LATE AFTERNOON...LIKELY COLLOCATED WITH SOME DRIER MIDLEVEL AIR.
0-6KM BULK SHEAR VALUES ARE FORECASTED TO INCREASE UPWARDS OF 30
KNOTS WITH THIS FEATURE. IN ADDITION...THE DRIER AIR COULD LEAD TO
SOME STEEPER MIDLEVEL LAPSE RATES THAT COULD CONTRIBUTE TO
RELATIVELY HIGHER CAPE VALUES. MODELS DIFFER BUT THE NAM MAX IS
ADVERTISING ML/SB CAPES OF OVER 2000 J/KG. GIVEN SOME OF THE CWA IS
UNDER A SLIGHT RISK IN SWODY1...SEE NO REASON WHY THERE WILL NOT BE
A SEE TEXT OR SLIGHT RISK DESIGNATION FOR WEDNESDAY. A
UNIDIRECTIONAL WIND PROFILE SUPPORTS ANY LINE SEGMENTS THAT DO
BECOME ORTHOGONAL TO THE MEAN WIND WILL CARRY A HIGHER WINDGUST
THREAT. AN ADDITIONAL THREAT TO MONITOR IS HEAVY RAIN POTENTIAL DUE
TO A SLOW STORM MOTION OF ROUGHLY 25 TO 30 MPH.

DRIER LOWER TROPOSPHERIC AIR AND THE LONGWAVE RIDGE AXIS WILL
FINALLY CATCH SOUTHEASTERN MICHIGAN ON THURSDAY. THIS IS EXPECTED TO
LEAD TO QUIET WEATHER WEDNESDAY NIGHT AND THROUGH THE FIRST HALF OF
THURSDAY. VIRTUALLY NO SURFACE RIDGING TO SPEAK OF AND A
REESTABLISHMENT OF THE UPPER LEVEL RIDGE TO OUR NORTH AND EAST WILL
ALLOW WARM AIR ADVECTION TO FLOOD TO THE NORTHEAST. THIS IS ACTUALLY
EXPECTED TO OCCUR RATHER RAPIDLY. IN STARK CONTRAST TO WHAT USUALLY
OCCURS DURING THE SPRINGTIME. AS A RESULT...MOISTURE/INSTABILITY AND
WARM AIR ADVECTION WILL RETURN RATHER QUICKLY AGAIN BY THURSDAY
AFTERNOON AND FRIDAY. BRING A MID CHANCE POPS IN THURSDAY AFTERNOON
FOR THE SOUTHWESTERN 1/3RD OF THE CWA LINGERING INTO THURSDAY NIGHT.
HUMID CONDITIONS ARE EXPECTED BOTH WEDNESDAY AND THURSDAY.

&&

.MARINE...

LIGHT WINDS WILL GIVE WAY TO A MODERATE SOUTHEAST BREEZE TODAY AND
THIS EVENING AS A WEAK LOW DRIFTS TROUGH THE AREA. WINDS WILL BE THE
STRONGEST ACROSS NORTHERN LAKE HURON BUT GUSTS THERE WILL STILL
STRUGGLE TO BREAK 20 KNOTS. THIS LOW WILL ALSO BRING A CHANCE FOR
THUNDERSTORMS BOTH TODAY AND WEDNESDAY...PARTICULARLY FOR THE
SOUTHERN LAKE HURON BASIN AND POINTS SOUTH.

&&

.AVIATION...ISSUED 1150 PM EDT MON AUG 18 2014

//DISCUSSION...

LOW LEVEL MOISTURE ADVECTION IS RESULTING IN AN EXPANDING REGION OF
STRATO CU BASED IN THE 3500 TO 4500 FT RANGE. THIS TREND WILL
CONTINUE DURING THE EARLY MORNING HOURS. THE APPROACH OF AN UPPER
LEVEL LOW WILL STEEPEN MID LEVEL LAPSE RATES EARLY THIS
MORNING...PROVIDING AN INCREASED CHANCE FOR SHOWERS. THE BEST
CHANCES EARLY THIS MORNING WILL CONTINUE TO BE AROUND MBS CLOSER TO
THE STRONGER LARGER SCALE SUPPORT. WHILE THERE IS A CHANCE FOR SOME
MORNING THUNDERSTORMS...THE CHANCES REMAIN A BIT TOO LOW TO INCLUDE
IN THE TAFS AT THIS TIME.

FOR DTW...SHOWER AND THUNDERSTORM CHANCES WILL BE A LITTLE LESS
AROUND METRO THIS MORNING AS THE BETTER FORCING WILL RESIDE FARTHER
NORTH. THE APPROACH OF THE UPPER LOW AND PEAK AFTERNOON HEATING WILL
PROVIDE A HIGH LIKELIHOOD OF SHOWERS AND THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE OF CEILINGS AOB 5000 FT THROUGH THE TAF PERIOD.

&&

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

&&

$$

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


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







000
FXUS63 KDTX 190350
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1150 PM EDT MON AUG 18 2014


.AVIATION...

//DISCUSSION...

LOW LEVEL MOISTURE ADVECTION IS RESULTING IN AN EXPANDING REGION OF
STRATO CU BASED IN THE 3500 TO 4500 FT RANGE. THIS TREND WILL
CONTINUE DURING THE EARLY MORNING HOURS. THE APPROACH OF AN UPPER
LEVEL LOW WILL STEEPEN MID LEVEL LAPSE RATES EARLY THIS
MORNING...PROVIDING AN INCREASED CHANCE FOR SHOWERS. THE BEST
CHANCES EARLY THIS MORNING WILL CONTINUE TO BE AROUND MBS CLOSER TO
THE STRONGER LARGER SCALE SUPPORT. WHILE THERE IS A CHANCE FOR SOME
MORNING THUNDERSTORMS...THE CHANCES REMAIN A BIT TOO LOW TO INCLUDE
IN THE TAFS AT THIS TIME.

FOR DTW...SHOWER AND THUNDERSTORM CHANCES WILL BE A LITTLE LESS
AROUND METRO THIS MORNING AS THE BETTER FORCING WILL RESIDE FARTHER
NORTH. THE APPROACH OF THE UPPER LOW AND PEAK AFTERNOON HEATING WILL
PROVIDE A HIGH LIKELIHOOD OF SHOWERS AND THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE OF CEILINGS AOB 5000 FT THROUGH THE TAF PERIOD.

&&

.PREV DISCUSSION...ISSUED 934 PM EDT MON AUG 18 2014

UPDATE...

THE ONGOING REGION OF CONVECTION NOW ADVANCING ACROSS NORTH
CENTRAL LAKE MI IS TIED TO A COUPLE OF MID LEVEL SHORT WAVE
IMPULSES ROTATING OUT OF WISCONSIN. THESE FEATURES WILL LARGELY
PASS WELL NORTH OF SE MI TONIGHT. THE WATER VAPOR IMAGERY DOES
HOWEVER SHOW A TRAILING RIBBON OF MOISTURE EXTENDING ACROSS WRN
LOWER MI. THERE HAS ALREADY BEEN SOME SHOWER DEVELOPMENT OVER
SOUTH CENTRAL LOWER MI ALONG THE LEAD EDGE OF THIS LOW LEVEL THETA
E RIDGE. THIS MOISTURE WILL SLOWLY ADVANCE FROM WEST TO EAST
ACROSS SE MI DURING THE OVERNIGHT. WHILE THE 00Z KDTX SOUNDING
SHOWS A STRONG MID LEVEL CAP...COLD AIR ADVECTION IN THE MID
LEVELS DURING THE NIGHT WILL ERODE THIS CAP AND PROVIDE A BETTER
CHANCE FOR THE DEVELOPMENT OF DEEPER CONVECTION. OVERALL THE
CURRENT FORECAST HAS THIS COVERED WELL AND MINIMAL UPDATES WILL BE
NEEDED THIS EVENING. AN UPDATED ZFP WILL BE ISSUED MAINLY TO
FRESHEN THE WORDING.

PREV DISCUSSION...ISSUED 322 PM EDT MON AUG 18 2014

SHORT TERM...TONIGHT

RIDGING AT THE SURFACE AND ALOFT THIS AFTERNOON OVER SOUTHEAST
MICHIGAN WILL BE SLIDING EAST EARLY THIS EVENING...ALLOWING FOR A
MODERATE SURGE OF MOISTURE...AS PW VALUES RAMP UP TO AROUND 1.5
INCHES AROUND OR JUST AFTER MIDNIGHT. ALTHOUGH...THE 850-700 MB
THETA-E RIDGE AXIS IS RATHER DIFFUSE AND NOT TERRIBLY FOCUSED. THROW
IN THE FACT THERE IS NOT MUCH OF A LOW LEVEL JET DEVELOPING TONIGHT
AHEAD OF OUR APPROACHING LOW PRESSURE SYSTEM ENTERING THE WESTERN
GREAT LAKES...AND CAN NOT ARGUE FOR MORE THAN CHANCE POPS
TONIGHT...WITH THE BEST CHANCE ACROSS THE TRI-CITIES REGION.
INSTABILITY IS MARGINAL...AS SHOWALTER INDEX GOES EVER SO SLIGHTLY
NEGATIVE FOR THE MOST PART...THUS JUST A SLIGHT CHANCE OF THUNDERSTORMS
(MAINLY WEST OF U.S 23). SURFACE DEW PTS AOA 60 DEGREES POINT TO
MINS PREDOMINATELY IN THE LOWER 60S.

LONG TERM...

THIS AFTERNOON`S WATER VAPOR IMAGERY INDICATES A CLOSED CIRCULATION
OVER EXTREME NORTHWEST MINNESOTA. THIS LOW IS FORECAST TO CONTINUE
CUTTING OFF FROM THE PREVAILING WESTERLY FLOW AND SLOWLY DRIFT
ACROSS THE GREAT LAKES TUESDAY THROUGH WEDNESDAY NIGHT.

SOUTHWESTERLY FLOW WILL INCREASE THROUGH THE DAY TUESDAY AS
WARM/MOIST ADVECTION AND ISENTROPIC ASCENT INCREASE IN ASSOCIATION
WITH EASTWARD PROGRESSION OF HEIGHT FALLS AND STRONGER SYNOPTIC SCALE
ASCENT. RATHER ILL-DEFINED FORCING IN THE ABSENCE OF A WELL-DEFINED
MID-LEVEL WAVE IS EXPECTED TO RESULT IN NOTHING MORE THAN AN
ISOLATED TO SCATTERED COVERAGE OF WARM ADVECTION TYPE CONVECTION
THROUGH THE FIRST HALF OF TUESDAY, MAINLY FURTHER WEST. WARM SW
FLOW WILL RESULT IN THE DEVELOPMENT OF A MODERATE CAP BY TUESDAY
AFTERNOON, BUT THE GUIDANCE, LOW AND HIGH-RES ALIKE, UNIVERSALLY
ALLOW CONVECTION TO DEVELOP WITHIN PREFRONTAL TROUGHING DURING THE
PEAK HEATING HOURS... A REASONABLE ENOUGH EXPECTATION. DEPENDING ON
EXACT TIMING, MODERATE DESTABILIZATION ACROSS THE EASTERN THIRD OR
SO OF THE CWA COULD RESULT IN A MARGINAL SEVERE THREAT, ALTHOUGH
UPDRAFTS WILL STRUGGLE TO ORGANIZE GIVEN THE SOUTHWARD DISPLACEMENT
OF THE BETTER SHEAR. THE BIGGER THREAT ATTM WILL BE HEAVY DOWNPOURS
GIVEN THE HIGH MOISTURE CONTENT AND DEEPENING WARM CLOUD LAYER FROM
8KFT IN THE MID-AFTERNOON TO 10KFT BY EVENING. A GENERAL HALF INCH
TO ISOLATED ONE INCH AMOUNT SEEMS REASONABLE. AMOUNTS MUCH HIGHER
THAN THAT ARE UNLIKELY GIVEN THE LACK OF ORGANIZED LARGER SCALE
FORCING AND THE EXPECTED TRANSIENT NATURE OF LOW-LEVEL CONVERGENT
AXIS.

A PERIOD OF DOWNTIME WILL ENSUE DURING THE LATE EVENING/OVERNIGHT
TUESDAY AS THE INITIAL FORCING DEPARTS PROGRESSES EAST AND NOCTURNAL
STABILIZATION GETS UNDERWAY. THE CLOSED UPPER LOW IS THEN FORECAST TO
SETTLE ALMOST DIRECTLY OVERHEAD ON WEDNESDAY. MOISTURE CONTENT WILL
REMAIN RATHER ROBUST, AROUND 1.5" PWAT WITH DEWPOINTS APPROACHING
70F. THE PRIMARY PV ANOMALY IS FORECAST TO ROTATE ACROSS THE AREA
DURING THE DAY, THE EXACT TIMING OF WHICH WILL PLAY A KEY ROLE IN
INTENSITY/COVERAGE OF THE CONVECTIVE RESPONSE. ONCE AGAIN, THE
PRIMARY CONCERN WILL BE HEAVY DOWNPOURS AS OPPOSED TO LEGITIMATE
SEVERE WEATHER. IT IS NOT OUT OF THE QUESTION THAT THE HEAVIEST
RAINFALL ACTUALLY OCCURS WEDNESDAY GIVEN THE LACK OF DEEP LAYER FLOW
WITH THE LOW OVERHEAD. SUBSIDENCE IN THE WAKE OF THE PV ANOMALY AND
NOCTURNAL COOLING WILL BRING AN END TO CONVECTION WEDNESDAY EVENING.
HIGHS BOTH TUES AND WED WILL BE SEASONAL, AROUND 80, THOUGH
INCREASING MOISTURE WILL LEAD TO A MUGGY FEEL AS WELL AS WARMER
OVERNIGHT LOWS IN THE MID 60S.

RAIN CHANCES WILL STICK AROUND THROUGH MUCH OF THE EXTENDED PERIOD
AS A SERIES OF SHORTWAVES AND LOW PRESSURE SYSTEMS IMPACT SOUTHEAST
MICHIGAN. HAVE LEFT CHANCE POPS IN THE FORECAST THROUGH SUNDAY
NIGHT. TIMING AND COVERAGE OF THE RAIN WILL HAVE TO BE FINE TUNED AS
THE WEEK PROGRESSES AND MODELS GET A BETTER HANDLE ON THESE
DISTURBANCES. TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS
IN THE UPPER 70S AND LOW 80S AND LOW TEMPERATURES IN THE MID 60S
THROUGH SUNDAY.

MARINE...

LIGHT WINDS WILL GIVE WAY TO A MODERATE SOUTHEAST BREEZE TUESDAY
INTO TUESDAY EVENING AS A WEAK LOW DRIFTS TROUGH THE AREA. WINDS
WILL BE THE STRONGEST ACROSS NORTHERN LAKE HURON BUT GUSTS THERE
WILL STILL STRUGGLE TO BREAK 20 KNOTS. THIS LOW WILL ALSO BRING A
CHANCE FOR THUNDERSTORMS BOTH TUESDAY AND WEDNESDAY...PARTICULARLY
FOR THE SOUTHERN LAKE HURON BASIN AND POINTS SOUTH.

&&

.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...SF
LONG TERM....JVC/RK
MARINE.......JVC


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








000
FXUS63 KDTX 190350
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1150 PM EDT MON AUG 18 2014


.AVIATION...

//DISCUSSION...

LOW LEVEL MOISTURE ADVECTION IS RESULTING IN AN EXPANDING REGION OF
STRATO CU BASED IN THE 3500 TO 4500 FT RANGE. THIS TREND WILL
CONTINUE DURING THE EARLY MORNING HOURS. THE APPROACH OF AN UPPER
LEVEL LOW WILL STEEPEN MID LEVEL LAPSE RATES EARLY THIS
MORNING...PROVIDING AN INCREASED CHANCE FOR SHOWERS. THE BEST
CHANCES EARLY THIS MORNING WILL CONTINUE TO BE AROUND MBS CLOSER TO
THE STRONGER LARGER SCALE SUPPORT. WHILE THERE IS A CHANCE FOR SOME
MORNING THUNDERSTORMS...THE CHANCES REMAIN A BIT TOO LOW TO INCLUDE
IN THE TAFS AT THIS TIME.

FOR DTW...SHOWER AND THUNDERSTORM CHANCES WILL BE A LITTLE LESS
AROUND METRO THIS MORNING AS THE BETTER FORCING WILL RESIDE FARTHER
NORTH. THE APPROACH OF THE UPPER LOW AND PEAK AFTERNOON HEATING WILL
PROVIDE A HIGH LIKELIHOOD OF SHOWERS AND THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING.

//DTW THRESHOLD THREATS...

* MEDIUM CONFIDENCE OF CEILINGS AOB 5000 FT THROUGH THE TAF PERIOD.

&&

.PREV DISCUSSION...ISSUED 934 PM EDT MON AUG 18 2014

UPDATE...

THE ONGOING REGION OF CONVECTION NOW ADVANCING ACROSS NORTH
CENTRAL LAKE MI IS TIED TO A COUPLE OF MID LEVEL SHORT WAVE
IMPULSES ROTATING OUT OF WISCONSIN. THESE FEATURES WILL LARGELY
PASS WELL NORTH OF SE MI TONIGHT. THE WATER VAPOR IMAGERY DOES
HOWEVER SHOW A TRAILING RIBBON OF MOISTURE EXTENDING ACROSS WRN
LOWER MI. THERE HAS ALREADY BEEN SOME SHOWER DEVELOPMENT OVER
SOUTH CENTRAL LOWER MI ALONG THE LEAD EDGE OF THIS LOW LEVEL THETA
E RIDGE. THIS MOISTURE WILL SLOWLY ADVANCE FROM WEST TO EAST
ACROSS SE MI DURING THE OVERNIGHT. WHILE THE 00Z KDTX SOUNDING
SHOWS A STRONG MID LEVEL CAP...COLD AIR ADVECTION IN THE MID
LEVELS DURING THE NIGHT WILL ERODE THIS CAP AND PROVIDE A BETTER
CHANCE FOR THE DEVELOPMENT OF DEEPER CONVECTION. OVERALL THE
CURRENT FORECAST HAS THIS COVERED WELL AND MINIMAL UPDATES WILL BE
NEEDED THIS EVENING. AN UPDATED ZFP WILL BE ISSUED MAINLY TO
FRESHEN THE WORDING.

PREV DISCUSSION...ISSUED 322 PM EDT MON AUG 18 2014

SHORT TERM...TONIGHT

RIDGING AT THE SURFACE AND ALOFT THIS AFTERNOON OVER SOUTHEAST
MICHIGAN WILL BE SLIDING EAST EARLY THIS EVENING...ALLOWING FOR A
MODERATE SURGE OF MOISTURE...AS PW VALUES RAMP UP TO AROUND 1.5
INCHES AROUND OR JUST AFTER MIDNIGHT. ALTHOUGH...THE 850-700 MB
THETA-E RIDGE AXIS IS RATHER DIFFUSE AND NOT TERRIBLY FOCUSED. THROW
IN THE FACT THERE IS NOT MUCH OF A LOW LEVEL JET DEVELOPING TONIGHT
AHEAD OF OUR APPROACHING LOW PRESSURE SYSTEM ENTERING THE WESTERN
GREAT LAKES...AND CAN NOT ARGUE FOR MORE THAN CHANCE POPS
TONIGHT...WITH THE BEST CHANCE ACROSS THE TRI-CITIES REGION.
INSTABILITY IS MARGINAL...AS SHOWALTER INDEX GOES EVER SO SLIGHTLY
NEGATIVE FOR THE MOST PART...THUS JUST A SLIGHT CHANCE OF THUNDERSTORMS
(MAINLY WEST OF U.S 23). SURFACE DEW PTS AOA 60 DEGREES POINT TO
MINS PREDOMINATELY IN THE LOWER 60S.

LONG TERM...

THIS AFTERNOON`S WATER VAPOR IMAGERY INDICATES A CLOSED CIRCULATION
OVER EXTREME NORTHWEST MINNESOTA. THIS LOW IS FORECAST TO CONTINUE
CUTTING OFF FROM THE PREVAILING WESTERLY FLOW AND SLOWLY DRIFT
ACROSS THE GREAT LAKES TUESDAY THROUGH WEDNESDAY NIGHT.

SOUTHWESTERLY FLOW WILL INCREASE THROUGH THE DAY TUESDAY AS
WARM/MOIST ADVECTION AND ISENTROPIC ASCENT INCREASE IN ASSOCIATION
WITH EASTWARD PROGRESSION OF HEIGHT FALLS AND STRONGER SYNOPTIC SCALE
ASCENT. RATHER ILL-DEFINED FORCING IN THE ABSENCE OF A WELL-DEFINED
MID-LEVEL WAVE IS EXPECTED TO RESULT IN NOTHING MORE THAN AN
ISOLATED TO SCATTERED COVERAGE OF WARM ADVECTION TYPE CONVECTION
THROUGH THE FIRST HALF OF TUESDAY, MAINLY FURTHER WEST. WARM SW
FLOW WILL RESULT IN THE DEVELOPMENT OF A MODERATE CAP BY TUESDAY
AFTERNOON, BUT THE GUIDANCE, LOW AND HIGH-RES ALIKE, UNIVERSALLY
ALLOW CONVECTION TO DEVELOP WITHIN PREFRONTAL TROUGHING DURING THE
PEAK HEATING HOURS... A REASONABLE ENOUGH EXPECTATION. DEPENDING ON
EXACT TIMING, MODERATE DESTABILIZATION ACROSS THE EASTERN THIRD OR
SO OF THE CWA COULD RESULT IN A MARGINAL SEVERE THREAT, ALTHOUGH
UPDRAFTS WILL STRUGGLE TO ORGANIZE GIVEN THE SOUTHWARD DISPLACEMENT
OF THE BETTER SHEAR. THE BIGGER THREAT ATTM WILL BE HEAVY DOWNPOURS
GIVEN THE HIGH MOISTURE CONTENT AND DEEPENING WARM CLOUD LAYER FROM
8KFT IN THE MID-AFTERNOON TO 10KFT BY EVENING. A GENERAL HALF INCH
TO ISOLATED ONE INCH AMOUNT SEEMS REASONABLE. AMOUNTS MUCH HIGHER
THAN THAT ARE UNLIKELY GIVEN THE LACK OF ORGANIZED LARGER SCALE
FORCING AND THE EXPECTED TRANSIENT NATURE OF LOW-LEVEL CONVERGENT
AXIS.

A PERIOD OF DOWNTIME WILL ENSUE DURING THE LATE EVENING/OVERNIGHT
TUESDAY AS THE INITIAL FORCING DEPARTS PROGRESSES EAST AND NOCTURNAL
STABILIZATION GETS UNDERWAY. THE CLOSED UPPER LOW IS THEN FORECAST TO
SETTLE ALMOST DIRECTLY OVERHEAD ON WEDNESDAY. MOISTURE CONTENT WILL
REMAIN RATHER ROBUST, AROUND 1.5" PWAT WITH DEWPOINTS APPROACHING
70F. THE PRIMARY PV ANOMALY IS FORECAST TO ROTATE ACROSS THE AREA
DURING THE DAY, THE EXACT TIMING OF WHICH WILL PLAY A KEY ROLE IN
INTENSITY/COVERAGE OF THE CONVECTIVE RESPONSE. ONCE AGAIN, THE
PRIMARY CONCERN WILL BE HEAVY DOWNPOURS AS OPPOSED TO LEGITIMATE
SEVERE WEATHER. IT IS NOT OUT OF THE QUESTION THAT THE HEAVIEST
RAINFALL ACTUALLY OCCURS WEDNESDAY GIVEN THE LACK OF DEEP LAYER FLOW
WITH THE LOW OVERHEAD. SUBSIDENCE IN THE WAKE OF THE PV ANOMALY AND
NOCTURNAL COOLING WILL BRING AN END TO CONVECTION WEDNESDAY EVENING.
HIGHS BOTH TUES AND WED WILL BE SEASONAL, AROUND 80, THOUGH
INCREASING MOISTURE WILL LEAD TO A MUGGY FEEL AS WELL AS WARMER
OVERNIGHT LOWS IN THE MID 60S.

RAIN CHANCES WILL STICK AROUND THROUGH MUCH OF THE EXTENDED PERIOD
AS A SERIES OF SHORTWAVES AND LOW PRESSURE SYSTEMS IMPACT SOUTHEAST
MICHIGAN. HAVE LEFT CHANCE POPS IN THE FORECAST THROUGH SUNDAY
NIGHT. TIMING AND COVERAGE OF THE RAIN WILL HAVE TO BE FINE TUNED AS
THE WEEK PROGRESSES AND MODELS GET A BETTER HANDLE ON THESE
DISTURBANCES. TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS
IN THE UPPER 70S AND LOW 80S AND LOW TEMPERATURES IN THE MID 60S
THROUGH SUNDAY.

MARINE...

LIGHT WINDS WILL GIVE WAY TO A MODERATE SOUTHEAST BREEZE TUESDAY
INTO TUESDAY EVENING AS A WEAK LOW DRIFTS TROUGH THE AREA. WINDS
WILL BE THE STRONGEST ACROSS NORTHERN LAKE HURON BUT GUSTS THERE
WILL STILL STRUGGLE TO BREAK 20 KNOTS. THIS LOW WILL ALSO BRING A
CHANCE FOR THUNDERSTORMS BOTH TUESDAY AND WEDNESDAY...PARTICULARLY
FOR THE SOUTHERN LAKE HURON BASIN AND POINTS SOUTH.

&&

.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...SF
LONG TERM....JVC/RK
MARINE.......JVC


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







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