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000
FXUS63 KDTX 041937
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
337 PM EDT TUE AUG 4 2015

.SHORT TERM...THIS EVENING AND TONIGHT

THE STRONG UPPER LEVEL LOW OVER HUDSON BAY HAS SENT ANOTHER SURFACE
TROUGH/COLD FRONT SOUTH THROUGH THE GREAT LAKES TODAY...VERY SIMILAR
TO THAT WHICH WE EXPERIENCED YESTERDAY. THE FRONT IS CURRENTLY
DRAPED ACROSS MID MI AND WILL BE DROPPING THROUGH SE MI EARLY
TONIGHT WHILE FURTHER WEAKENING. JUST AHEAD OF THE FRONT WE WERE
ABLE TO GENERATE A FEW HUNDRED J/KG OF CAPE AS TEMPS ONCE AGAIN MADE
IT INTO THE UPPER 70S. DEWPOINTS ONLY IN THE MID 50S...VS MID 60S
YESTERDAY...ARE LIMITING THE INSTABILITY THUS THE COVERAGE OF
SHOWERS TODAY. ADDITIONAL MID LEVEL DRY AIR ACROSS THE SOUTHERN HALF
OF THE AREA HAS KEPT ALL SHOWER ACTIVITY NORTH OF PTK. WITH THE LOSS
OF DAYTIME HEATING...CONVECTION WILL END QUICKLY THIS EVENING AND
SKIES WILL CLEAR OUT FOR THE OVERNIGHT. THE CLEARING SKIES AND DRY
NORTHERLY FLOW WILL SET US UP FOR ANOTHER NIGHT OF EFFECTIVE
RADIATIVE COOLING WITH TEMPS FALLING TO INTO THE LOW 50S NORTH OF
M59 AND MID 50S SOUTH OF M59.

&&

.LONG TERM...

AS STRONG UPPER LOW OVER EASTERN CANADA PULLS OFF TO THE EAST AND
NORTHEAST...EXPECT DRY WEATHER INTO DURING THE WEDNESDAY/THURSDAY
TIME FRAME. SURFACE HIGH PRESSURE WILL SETTLE OVER THE REGION BY
WEDNESDAY AND HOLD INTO THURSDAY AS LOW PRESSURE EMERGING FROM THE
CENTRAL PLAINS IS SHUNTED SOUTHEAST AROUND CONFLUENCE NORTHWEST
UPPER LEVEL FLOW ON THE BACK SIDE OF MEAN UPPER TROUGH AXIS OVER
EASTERN CANADA/NORTHEAST CONUS.

WITH A DRY AND COOL TO MILD AIRMASS IN PLACE WITH THIS AREA OF HIGH
PRESSURE...EXPECT MAXIMUM TEMPERATURES TO RANGE...ON AVERAGE...IN
THE MIDDLE 70S BOTH DAYS AND LOWS TO FALL INTO THE 50S TO AROUND
60...SOME 3 TO 5 DEGREES BELOW AVERAGE FOR EARLY AUGUST.

FRIDAY THROUGH TUESDAY.

MODEL AGREEMENT CONTINUES TO STRUGGLE FOR THE LONG RANGE IN TERMS OF
TIMING AND LOW INTENSITY. SUFFICE TO SAY A SERIES OF UPPER LEVEL
DISTURBANCES WILL KEEP AT LEAST SOME CHANCES FOR SHOWERS IN THE
FORECAST THROUGH EARLY NEXT WEEK. TEMPERATURE TREND STILL AIMING
BELOW AVERAGE THROUGH THE PERIOD.

&&

.MARINE...

NORTHWEST FLOW WILL DEVELOP IN THE WAKE OF A PASSING COLD FRONT.
WIND GUSTS MAY APPROACH 25 KNOTS OVER THE OPEN WATERS OF LAKE HURON
AT TIMES AS THIS COOLER AIR PUSHES SOUTHEAST. WHILE WAVES WILL
INCREASE OVER THE NEARSHORE WATERS...THE NORTHWEST TRAJECTORY SHOULD
LIMIT WAVES ENOUGH TO PRECLUDE SMALL CRAFT ADVISORIES. WINDS WILL
SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE SYSTEM APPROACHES
WITH A LIGHT AND VARIABLE WIND FIELD EXPECTED THURSDAY INTO
FRIDAY AS THIS HIGH SETTLES OVER THE REGION.

&&

.AVIATION...ISSUED 124 PM EDT TUE AUG 4 2015

AN AGITATED CU FIELD IS DEVELOPING AHEAD OF THE NEXT WEAK FRONTAL
BOUNDARY CURRENTLY DROPPING THROUGH CENTRAL MI. VFR CONDITIONS
SHOULD PREVAIL THROUGH MUCH OF THE FORECAST WITH HIGH BASED CEILINGS
STAYING UP AROUND 5-6KFT. SOME ISOLATED SHOWER/THUNDERSTORM ACTIVITY
WILL PASS THROUGH THE AREA DURING PEAK HEATING THIS AFTERNOON BUT
MAINLY ONLY AFFECT FNT AND MBS...POSSIBLY BRUSHING PTK. WESTERLY
FLOW WILL REMAIN ELEVATED THIS AFTERNOON WITH GUSTS TO 20 KNOTS.
WINDS WILL RELAX TONIGHT WHILE BECOMING NORTHWEST UNDER CLEARING
SKIES.

FOR DTW...DAYTIME HEATING...COUPLED WITH A WEAK FRONTAL BOUNDARY
SWINGING SOUTH THROUGH LOWER MICHIGAN...IS EXPECTED TO RESULT AN
ENHANCED CU FIELD BUT CEILINGS SHOULD REMAIN VFR...GENERALLY ABOVE
5000 FEET. SHOWER/THUNDERSTORMS ACTIVITY IS EXPECTED TO REMAIN NORTH
OF THE AIRPORT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL THIS AFTERNOON.

&&

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

$$

SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG
AVIATION.....DRK


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





000
FXUS63 KDTX 041937
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
337 PM EDT TUE AUG 4 2015

.SHORT TERM...THIS EVENING AND TONIGHT

THE STRONG UPPER LEVEL LOW OVER HUDSON BAY HAS SENT ANOTHER SURFACE
TROUGH/COLD FRONT SOUTH THROUGH THE GREAT LAKES TODAY...VERY SIMILAR
TO THAT WHICH WE EXPERIENCED YESTERDAY. THE FRONT IS CURRENTLY
DRAPED ACROSS MID MI AND WILL BE DROPPING THROUGH SE MI EARLY
TONIGHT WHILE FURTHER WEAKENING. JUST AHEAD OF THE FRONT WE WERE
ABLE TO GENERATE A FEW HUNDRED J/KG OF CAPE AS TEMPS ONCE AGAIN MADE
IT INTO THE UPPER 70S. DEWPOINTS ONLY IN THE MID 50S...VS MID 60S
YESTERDAY...ARE LIMITING THE INSTABILITY THUS THE COVERAGE OF
SHOWERS TODAY. ADDITIONAL MID LEVEL DRY AIR ACROSS THE SOUTHERN HALF
OF THE AREA HAS KEPT ALL SHOWER ACTIVITY NORTH OF PTK. WITH THE LOSS
OF DAYTIME HEATING...CONVECTION WILL END QUICKLY THIS EVENING AND
SKIES WILL CLEAR OUT FOR THE OVERNIGHT. THE CLEARING SKIES AND DRY
NORTHERLY FLOW WILL SET US UP FOR ANOTHER NIGHT OF EFFECTIVE
RADIATIVE COOLING WITH TEMPS FALLING TO INTO THE LOW 50S NORTH OF
M59 AND MID 50S SOUTH OF M59.

&&

.LONG TERM...

AS STRONG UPPER LOW OVER EASTERN CANADA PULLS OFF TO THE EAST AND
NORTHEAST...EXPECT DRY WEATHER INTO DURING THE WEDNESDAY/THURSDAY
TIME FRAME. SURFACE HIGH PRESSURE WILL SETTLE OVER THE REGION BY
WEDNESDAY AND HOLD INTO THURSDAY AS LOW PRESSURE EMERGING FROM THE
CENTRAL PLAINS IS SHUNTED SOUTHEAST AROUND CONFLUENCE NORTHWEST
UPPER LEVEL FLOW ON THE BACK SIDE OF MEAN UPPER TROUGH AXIS OVER
EASTERN CANADA/NORTHEAST CONUS.

WITH A DRY AND COOL TO MILD AIRMASS IN PLACE WITH THIS AREA OF HIGH
PRESSURE...EXPECT MAXIMUM TEMPERATURES TO RANGE...ON AVERAGE...IN
THE MIDDLE 70S BOTH DAYS AND LOWS TO FALL INTO THE 50S TO AROUND
60...SOME 3 TO 5 DEGREES BELOW AVERAGE FOR EARLY AUGUST.

FRIDAY THROUGH TUESDAY.

MODEL AGREEMENT CONTINUES TO STRUGGLE FOR THE LONG RANGE IN TERMS OF
TIMING AND LOW INTENSITY. SUFFICE TO SAY A SERIES OF UPPER LEVEL
DISTURBANCES WILL KEEP AT LEAST SOME CHANCES FOR SHOWERS IN THE
FORECAST THROUGH EARLY NEXT WEEK. TEMPERATURE TREND STILL AIMING
BELOW AVERAGE THROUGH THE PERIOD.

&&

.MARINE...

NORTHWEST FLOW WILL DEVELOP IN THE WAKE OF A PASSING COLD FRONT.
WIND GUSTS MAY APPROACH 25 KNOTS OVER THE OPEN WATERS OF LAKE HURON
AT TIMES AS THIS COOLER AIR PUSHES SOUTHEAST. WHILE WAVES WILL
INCREASE OVER THE NEARSHORE WATERS...THE NORTHWEST TRAJECTORY SHOULD
LIMIT WAVES ENOUGH TO PRECLUDE SMALL CRAFT ADVISORIES. WINDS WILL
SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE SYSTEM APPROACHES
WITH A LIGHT AND VARIABLE WIND FIELD EXPECTED THURSDAY INTO
FRIDAY AS THIS HIGH SETTLES OVER THE REGION.

&&

.AVIATION...ISSUED 124 PM EDT TUE AUG 4 2015

AN AGITATED CU FIELD IS DEVELOPING AHEAD OF THE NEXT WEAK FRONTAL
BOUNDARY CURRENTLY DROPPING THROUGH CENTRAL MI. VFR CONDITIONS
SHOULD PREVAIL THROUGH MUCH OF THE FORECAST WITH HIGH BASED CEILINGS
STAYING UP AROUND 5-6KFT. SOME ISOLATED SHOWER/THUNDERSTORM ACTIVITY
WILL PASS THROUGH THE AREA DURING PEAK HEATING THIS AFTERNOON BUT
MAINLY ONLY AFFECT FNT AND MBS...POSSIBLY BRUSHING PTK. WESTERLY
FLOW WILL REMAIN ELEVATED THIS AFTERNOON WITH GUSTS TO 20 KNOTS.
WINDS WILL RELAX TONIGHT WHILE BECOMING NORTHWEST UNDER CLEARING
SKIES.

FOR DTW...DAYTIME HEATING...COUPLED WITH A WEAK FRONTAL BOUNDARY
SWINGING SOUTH THROUGH LOWER MICHIGAN...IS EXPECTED TO RESULT AN
ENHANCED CU FIELD BUT CEILINGS SHOULD REMAIN VFR...GENERALLY ABOVE
5000 FEET. SHOWER/THUNDERSTORMS ACTIVITY IS EXPECTED TO REMAIN NORTH
OF THE AIRPORT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL THIS AFTERNOON.

&&

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

$$

SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG
AVIATION.....DRK


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




000
FXUS63 KDTX 041724
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
124 PM EDT TUE AUG 4 2015


.AVIATION...

AN AGITATED CU FIELD IS DEVELOPING AHEAD OF THE NEXT WEAK FRONTAL
BOUNDARY CURRENTLY DROPPING THROUGH CENTRAL MI. VFR CONDITIONS
SHOULD PREVAIL THROUGH MUCH OF THE FORECAST WITH HIGH BASED CEILINGS
STAYING UP AROUND 5-6KFT. SOME ISOLATED SHOWER/THUNDERSTORM ACTIVITY
WILL PASS THROUGH THE AREA DURING PEAK HEATING THIS AFTERNOON BUT
MAINLY ONLY AFFECT FNT AND MBS...POSSIBLY BRUSHING PTK. WESTERLY
FLOW WILL REMAIN ELEVATED THIS AFTERNOON WITH GUSTS TO 20 KNOTS.
WINDS WILL RELAX TONIGHT WHILE BECOMING NORTHWEST UNDER CLEARING
SKIES.

FOR DTW...DAYTIME HEATING...COUPLED WITH A WEAK FRONTAL BOUNDARY
SWINGING SOUTH THROUGH LOWER MICHIGAN...IS EXPECTED TO RESULT AN
ENHANCED CU FIELD BUT CEILINGS SHOULD REMAIN VFR...GENERALLY ABOVE
5000 FEET. SHOWER/THUNDERSTORMS ACTIVITY IS EXPECTED TO REMAIN NORTH
OF THE AIRPORT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL THIS AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 334 AM EDT TUE AUG 4 2015

SHORT TERM...TODAY AND TONIGHT

DRIER LOW LEVEL AIR IN PLACE ACROSS SOUTHEAST MICHIGAN AS INDICATED
BY THE SURFACE DEW PTS IN THE 50S. HOWEVER...THE MID LEVELS ARE
SIGNIFICANTLY COLDER...WITH THE 00Z RAOB OUT OF GREEN BAY REPORTING
A 500 MB TEMP OF -17 C. THUS...WITH SOME SEMBLANCE OF SURFACE
TROUGH/COLD FRONT MOVING THROUGH CENTRAL LOWER MICHIGAN DURING PEAK
HEATING...ENOUGH INSTABILITY AND CAPE (UP TO 500 J/KG) TO GENERATE
SCATTERED SHOWERS TODAY...WITH EQL LEVELS EVEN POTENTIALLY SLIPPING
BY 20000 FEET TO GENERATE ISOLATED THUNDERSTORMS...WITH GREATEST
CONCENTRATION OF ACTIVITY ACROSS THE NORTHERN THUMB REGION. FARTHER
SOUTH TOWARD THE OHIO BORDER...MID LEVEL DRY AIR SEEN IN THE WATER
VAPOR IMAGERY AND 700 MB RH FIELDS SHOULD BE SUFFICIENT TO CAP
ACTIVITY...AND SUBSEQUENTLY SHOULD SEE HIGHS SNEAK BACK INTO THE
LOWER 80S FROM DETROIT SOUTH WITH 850 MB TEMPS UP AROUND 12 C.
COOLER 850 MB TEMPS FARTHER NORTH...COUPLED WITH THE ADDITIONAL
CLOUD COVERAGE AND SHOWERS SHOULD HOLD LOCATIONS NORTH OF M-59 IN
THE UPPER 70S. PRETTY GOOD LOW LEVEL COLD ADVECTION THIS
EVENING/TONIGHT WITH 925 MB TEMPS LOWERING INTO THE LOWER
TEENS...AND WITH SURFACE WINDS TRENDING TOWARD CALM...GOOD RADIATORS
SHOULD MAKE A RUN TOWARD 50 DEGREES...ASSUMING THERE IS LITTLE IN
THE WAY OF 5000-6000 KFT CLOUDS LINGERING WITH WEAK 850 MB
FGEN/BAROCLINIC ZONE...OTHERWISE MINS HOLDING IN THE 50S.

LONG TERM...

STRONG ANTICYCLONIC VORTICITY ADVECTION BACKED BY GEOPOTENTIAL
HEIGHT REBOUND WILL PROVIDE A PERFECT SETUP FOR STRONG SURFACE HIGH
PRESSURE OVER THE GREAT LAKES REGION ON WEDNESDAY. MODEL DATA
SUPPORTS THIS NOTION DEPICTING THE CENTER OF THE ANTICYCLONE
SHIFTING FROM THE LAKE MICHIGAN-SUPERIOR AGGREGATE TO THE LAKE
SUPERIOR-HURON AGGREGATE BY 00Z THURSDAY. EVEN THE MOIST-BIASED NAM
IS SHOWING A STRONGLY STABLE COLUMN WITH STRONG STABILITY BETWEEN 5
AND 20 KFT AGL. EXPECTING A HIGH AMOUNT OF INSOLATION AND
THUS...RAISED HIGHS SLIGHTLY WITH MID TO UPPER 70S LIKELY ACROSS
MUCH OF SEMICH. THE EXCEPTION...LOWER 70S...WILL IN BE THE NORTHERN
THUMB WHERE LOCALIZED WINDS OFF OF LAKE HURON WILL LIKELY CAUSE SOME
INLAND PENETRATION OF THE MARINE LAYER.

DAMPENING MIDLEVEL RIDGE AXIS WILL THEN WORK ACROSS SOUTHEASTERN
MICHIGAN WEDNESDAY NIGHT AND THROUGH MUCH OF THE DAY ON THURSDAY.
THE ASSOCIATED ANTICYCLONIC VORTICITY BUBBLE IS SHOWN TO BE OVERHEAD
12Z THURSDAY BEFORE PASSING EASTWARD DURING THE MIDDAY PERIOD. THIS
WILL CAUSE THE REMNANT SURFACE RIDGING TO BEGIN RETREATING EASTWARD
BUT ALL SIGNS ARE IT WILL MAINTAIN CONTROL LOCALLY. IMPRESSIVE
SHORTWAVE IS FORECASTED TO SLIDE ALONG THE OHIO RIVER ON THURSDAY.
MODELS ARE UNAMINOUS IN KEEPING MEASURABLE PRECIPATION WELL SOUTH OF
THE OHIO-MICHIGAN STATELINE. ATTM...MODELS ARE ALSO SHOWING IT TO BE
A REAL STRUGGLE IN BRINGING THE HIGH CLOUD CANOPY THIS FAR
NORTHWARD. THERE IS A BIG DIFFERENCE BETWEEN THE NAM AND OTHER
SOLUTIONS...WITH THE NAM DEVELOPING A WEAK LOWER TROPOSPHERIC
FRONTAL BOUNDARY OVER THE NORTHERN CWA AS DIFFERENTIAL FLOW DEVELOPS
WITH A SECONDARY SURFACE HIGH NOSING SOUTHWARD DOWN NORTHERN LAKE
HURON. WITH ENHANCED CONVERGENCE ALONG THIS BOUNDARY THE NAM IS MORE
THAN WILLING TO PRODUCE PRECIPIATION ALONG IT BY THE AFTERNOON
HOURS. THERE IS A NON-ZERO POTENTIAL WITH SOME SUPPORT FROM VERY
WEAK BROAD MID TO UPPER LEVEL DEFORMATION FORCING. HOWEVER...
CONFIDENCE IS WAY TOO LOW TO JUMP ON THIS SOLUTION AND WILL MAINTAIN
A DRY FORECAST. ANY SATURATION WITHIN THE NAM BUFR SOUNDINGS IS FAR
FROM IMPRESSIVE. BUMPED HIGHS AGAIN UPWARD INTO THE UPPER 70S MOST
AREAS...COOLER AGAIN NEAR THE LAKESHORE.

MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THIS SETUP WILL YIELD SCATTERED SHOWERS AND A
FEW THUNDERSTORMS AGAIN TO MAINLY LAKE HURON THIS AFTERNOON AND
EVENING. A SECONDARY COLD FRONT WILL BRING SLIGHTLY STRONGER WINDS
WITH GUSTS IN THE 25 KNOT RANGE TODAY. WHILE THIS SYSTEM MAY BRING
CONDITIONS APPROACHING SMALL CRAFT ADVISORIES...THE DUE WESTERLY
TRAJECTORY WILL KEEP THE FETCH UNFAVORABLE FOR THE NEARSHORE AREAS
ALONG SOUTHEASTERN MICHIGAN. WINDS WILL THEN SLOWLY DECREASE ON
WEDNESDAY AS A HIGH PRESSURE SYSTEM APPROACHES WITH A LIGHT AND
VARIABLE WIND FIELD ON THURSDAY AS THIS HIGH BUILDS OVER THE REGION.

&&

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

$$

AVIATION.....DRK
SHORT TERM...SF
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 041724
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
124 PM EDT TUE AUG 4 2015


.AVIATION...

AN AGITATED CU FIELD IS DEVELOPING AHEAD OF THE NEXT WEAK FRONTAL
BOUNDARY CURRENTLY DROPPING THROUGH CENTRAL MI. VFR CONDITIONS
SHOULD PREVAIL THROUGH MUCH OF THE FORECAST WITH HIGH BASED CEILINGS
STAYING UP AROUND 5-6KFT. SOME ISOLATED SHOWER/THUNDERSTORM ACTIVITY
WILL PASS THROUGH THE AREA DURING PEAK HEATING THIS AFTERNOON BUT
MAINLY ONLY AFFECT FNT AND MBS...POSSIBLY BRUSHING PTK. WESTERLY
FLOW WILL REMAIN ELEVATED THIS AFTERNOON WITH GUSTS TO 20 KNOTS.
WINDS WILL RELAX TONIGHT WHILE BECOMING NORTHWEST UNDER CLEARING
SKIES.

FOR DTW...DAYTIME HEATING...COUPLED WITH A WEAK FRONTAL BOUNDARY
SWINGING SOUTH THROUGH LOWER MICHIGAN...IS EXPECTED TO RESULT AN
ENHANCED CU FIELD BUT CEILINGS SHOULD REMAIN VFR...GENERALLY ABOVE
5000 FEET. SHOWER/THUNDERSTORMS ACTIVITY IS EXPECTED TO REMAIN NORTH
OF THE AIRPORT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL THIS AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 334 AM EDT TUE AUG 4 2015

SHORT TERM...TODAY AND TONIGHT

DRIER LOW LEVEL AIR IN PLACE ACROSS SOUTHEAST MICHIGAN AS INDICATED
BY THE SURFACE DEW PTS IN THE 50S. HOWEVER...THE MID LEVELS ARE
SIGNIFICANTLY COLDER...WITH THE 00Z RAOB OUT OF GREEN BAY REPORTING
A 500 MB TEMP OF -17 C. THUS...WITH SOME SEMBLANCE OF SURFACE
TROUGH/COLD FRONT MOVING THROUGH CENTRAL LOWER MICHIGAN DURING PEAK
HEATING...ENOUGH INSTABILITY AND CAPE (UP TO 500 J/KG) TO GENERATE
SCATTERED SHOWERS TODAY...WITH EQL LEVELS EVEN POTENTIALLY SLIPPING
BY 20000 FEET TO GENERATE ISOLATED THUNDERSTORMS...WITH GREATEST
CONCENTRATION OF ACTIVITY ACROSS THE NORTHERN THUMB REGION. FARTHER
SOUTH TOWARD THE OHIO BORDER...MID LEVEL DRY AIR SEEN IN THE WATER
VAPOR IMAGERY AND 700 MB RH FIELDS SHOULD BE SUFFICIENT TO CAP
ACTIVITY...AND SUBSEQUENTLY SHOULD SEE HIGHS SNEAK BACK INTO THE
LOWER 80S FROM DETROIT SOUTH WITH 850 MB TEMPS UP AROUND 12 C.
COOLER 850 MB TEMPS FARTHER NORTH...COUPLED WITH THE ADDITIONAL
CLOUD COVERAGE AND SHOWERS SHOULD HOLD LOCATIONS NORTH OF M-59 IN
THE UPPER 70S. PRETTY GOOD LOW LEVEL COLD ADVECTION THIS
EVENING/TONIGHT WITH 925 MB TEMPS LOWERING INTO THE LOWER
TEENS...AND WITH SURFACE WINDS TRENDING TOWARD CALM...GOOD RADIATORS
SHOULD MAKE A RUN TOWARD 50 DEGREES...ASSUMING THERE IS LITTLE IN
THE WAY OF 5000-6000 KFT CLOUDS LINGERING WITH WEAK 850 MB
FGEN/BAROCLINIC ZONE...OTHERWISE MINS HOLDING IN THE 50S.

LONG TERM...

STRONG ANTICYCLONIC VORTICITY ADVECTION BACKED BY GEOPOTENTIAL
HEIGHT REBOUND WILL PROVIDE A PERFECT SETUP FOR STRONG SURFACE HIGH
PRESSURE OVER THE GREAT LAKES REGION ON WEDNESDAY. MODEL DATA
SUPPORTS THIS NOTION DEPICTING THE CENTER OF THE ANTICYCLONE
SHIFTING FROM THE LAKE MICHIGAN-SUPERIOR AGGREGATE TO THE LAKE
SUPERIOR-HURON AGGREGATE BY 00Z THURSDAY. EVEN THE MOIST-BIASED NAM
IS SHOWING A STRONGLY STABLE COLUMN WITH STRONG STABILITY BETWEEN 5
AND 20 KFT AGL. EXPECTING A HIGH AMOUNT OF INSOLATION AND
THUS...RAISED HIGHS SLIGHTLY WITH MID TO UPPER 70S LIKELY ACROSS
MUCH OF SEMICH. THE EXCEPTION...LOWER 70S...WILL IN BE THE NORTHERN
THUMB WHERE LOCALIZED WINDS OFF OF LAKE HURON WILL LIKELY CAUSE SOME
INLAND PENETRATION OF THE MARINE LAYER.

DAMPENING MIDLEVEL RIDGE AXIS WILL THEN WORK ACROSS SOUTHEASTERN
MICHIGAN WEDNESDAY NIGHT AND THROUGH MUCH OF THE DAY ON THURSDAY.
THE ASSOCIATED ANTICYCLONIC VORTICITY BUBBLE IS SHOWN TO BE OVERHEAD
12Z THURSDAY BEFORE PASSING EASTWARD DURING THE MIDDAY PERIOD. THIS
WILL CAUSE THE REMNANT SURFACE RIDGING TO BEGIN RETREATING EASTWARD
BUT ALL SIGNS ARE IT WILL MAINTAIN CONTROL LOCALLY. IMPRESSIVE
SHORTWAVE IS FORECASTED TO SLIDE ALONG THE OHIO RIVER ON THURSDAY.
MODELS ARE UNAMINOUS IN KEEPING MEASURABLE PRECIPATION WELL SOUTH OF
THE OHIO-MICHIGAN STATELINE. ATTM...MODELS ARE ALSO SHOWING IT TO BE
A REAL STRUGGLE IN BRINGING THE HIGH CLOUD CANOPY THIS FAR
NORTHWARD. THERE IS A BIG DIFFERENCE BETWEEN THE NAM AND OTHER
SOLUTIONS...WITH THE NAM DEVELOPING A WEAK LOWER TROPOSPHERIC
FRONTAL BOUNDARY OVER THE NORTHERN CWA AS DIFFERENTIAL FLOW DEVELOPS
WITH A SECONDARY SURFACE HIGH NOSING SOUTHWARD DOWN NORTHERN LAKE
HURON. WITH ENHANCED CONVERGENCE ALONG THIS BOUNDARY THE NAM IS MORE
THAN WILLING TO PRODUCE PRECIPIATION ALONG IT BY THE AFTERNOON
HOURS. THERE IS A NON-ZERO POTENTIAL WITH SOME SUPPORT FROM VERY
WEAK BROAD MID TO UPPER LEVEL DEFORMATION FORCING. HOWEVER...
CONFIDENCE IS WAY TOO LOW TO JUMP ON THIS SOLUTION AND WILL MAINTAIN
A DRY FORECAST. ANY SATURATION WITHIN THE NAM BUFR SOUNDINGS IS FAR
FROM IMPRESSIVE. BUMPED HIGHS AGAIN UPWARD INTO THE UPPER 70S MOST
AREAS...COOLER AGAIN NEAR THE LAKESHORE.

MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THIS SETUP WILL YIELD SCATTERED SHOWERS AND A
FEW THUNDERSTORMS AGAIN TO MAINLY LAKE HURON THIS AFTERNOON AND
EVENING. A SECONDARY COLD FRONT WILL BRING SLIGHTLY STRONGER WINDS
WITH GUSTS IN THE 25 KNOT RANGE TODAY. WHILE THIS SYSTEM MAY BRING
CONDITIONS APPROACHING SMALL CRAFT ADVISORIES...THE DUE WESTERLY
TRAJECTORY WILL KEEP THE FETCH UNFAVORABLE FOR THE NEARSHORE AREAS
ALONG SOUTHEASTERN MICHIGAN. WINDS WILL THEN SLOWLY DECREASE ON
WEDNESDAY AS A HIGH PRESSURE SYSTEM APPROACHES WITH A LIGHT AND
VARIABLE WIND FIELD ON THURSDAY AS THIS HIGH BUILDS OVER THE REGION.

&&

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

$$

AVIATION.....DRK
SHORT TERM...SF
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 041112
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
712 AM EDT TUE AUG 4 2015


.AVIATION...

COOL MID LEVELS OVER THE GREAT LAKES REGION WILL PROMOTE SCT-BKN
CLOUDS IN THE 5-8 KFT RANGE TODAY...WITH SURFACE COLD FRONT
PROVIDING FOCUS FOR SCATTERED SHOWER AND ISOLATED THUNDERSTORM
DEVELOPMENT...MAINLY NORTH OF PTK. DUE TO LIMITED COVERAGE...JUST
PUT SHOWER MENTION AT MBS FOR THE EARLY AFTERNOON HOURS...WHERE
CONFIDENCE IS A BIT HIGHER. WESTERLY WINDS TOPPING OUT AROUND 20
KNOTS THIS AFTERNOON WILL QUICKLY DIMINISH TOWARD SUNSET...WITH
SKIES BECOMING MOSTLY CLEAR.

FOR DTW...DAYTIME HEATING...COUPLED WITH A WEAK FRONTAL BOUNDARY
SWINGING SOUTH THROUGH LOWER MICHIGAN IS EXPECTED TO RESULT IN VFR
CEILINGS THIS AFTERNOON...BUT GENERALLY ABOVE 5000 FEET. SHOWER
AND POSSIBLE THUNDERSTORM ACTIVITY IS EXPECTED TO REMAIN NORTH OF
THE AIRPORT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS AOB 5000 FT AGL THIS AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 334 AM EDT TUE AUG 4 2015

SHORT TERM...TODAY AND TONIGHT

DRIER LOW LEVEL AIR IN PLACE ACROSS SOUTHEAST MICHIGAN AS INDICATED
BY THE SURFACE DEW PTS IN THE 50S. HOWEVER...THE MID LEVELS ARE
SIGNIFICANTLY COLDER...WITH THE 00Z RAOB OUT OF GREEN BAY REPORTING
A 500 MB TEMP OF -17 C. THUS...WITH SOME SEMBLANCE OF SURFACE
TROUGH/COLD FRONT MOVING THROUGH CENTRAL LOWER MICHIGAN DURING PEAK
HEATING...ENOUGH INSTABILITY AND CAPE (UP TO 500 J/KG) TO GENERATE
SCATTERED SHOWERS TODAY...WITH EQL LEVELS EVEN POTENTIALLY SLIPPING
BY 20000 FEET TO GENERATE ISOLATED THUNDERSTORMS...WITH GREATEST
CONCENTRATION OF ACTIVITY ACROSS THE NORTHERN THUMB REGION. FARTHER
SOUTH TOWARD THE OHIO BORDER...MID LEVEL DRY AIR SEEN IN THE WATER
VAPOR IMAGERY AND 700 MB RH FIELDS SHOULD BE SUFFICIENT TO CAP
ACTIVITY...AND SUBSEQUENTLY SHOULD SEE HIGHS SNEAK BACK INTO THE
LOWER 80S FROM DETROIT SOUTH WITH 850 MB TEMPS UP AROUND 12 C.
COOLER 850 MB TEMPS FARTHER NORTH...COUPLED WITH THE ADDITIONAL
CLOUD COVERAGE AND SHOWERS SHOULD HOLD LOCATIONS NORTH OF M-59 IN
THE UPPER 70S. PRETTY GOOD LOW LEVEL COLD ADVECTION THIS
EVENING/TONIGHT WITH 925 MB TEMPS LOWERING INTO THE LOWER
TEENS...AND WITH SURFACE WINDS TRENDING TOWARD CALM...GOOD RADIATORS
SHOULD MAKE A RUN TOWARD 50 DEGREES...ASSUMING THERE IS LITTLE IN
THE WAY OF 5000-6000 KFT CLOUDS LINGERING WITH WEAK 850 MB
FGEN/BAROCLINIC ZONE...OTHERWISE MINS HOLDING IN THE 50S.

LONG TERM...

STRONG ANTICYCLONIC VORTICITY ADVECTION BACKED BY GEOPOTENTIAL
HEIGHT REBOUND WILL PROVIDE A PERFECT SETUP FOR STRONG SURFACE HIGH
PRESSURE OVER THE GREAT LAKES REGION ON WEDNESDAY. MODEL DATA
SUPPORTS THIS NOTION DEPICTING THE CENTER OF THE ANTICYCLONE
SHIFTING FROM THE LAKE MICHIGAN-SUPERIOR AGGREGATE TO THE LAKE
SUPERIOR-HURON AGGREGATE BY 00Z THURSDAY. EVEN THE MOIST-BIASED NAM
IS SHOWING A STRONGLY STABLE COLUMN WITH STRONG STABILITY BETWEEN 5
AND 20 KFT AGL. EXPECTING A HIGH AMOUNT OF INSOLATION AND
THUS...RAISED HIGHS SLIGHTLY WITH MID TO UPPER 70S LIKELY ACROSS
MUCH OF SEMICH. THE EXCEPTION...LOWER 70S...WILL IN BE THE NORTHERN
THUMB WHERE LOCALIZED WINDS OFF OF LAKE HURON WILL LIKELY CAUSE SOME
INLAND PENETRATION OF THE MARINE LAYER.

DAMPENING MIDLEVEL RIDGE AXIS WILL THEN WORK ACROSS SOUTHEASTERN
MICHIGAN WEDNESDAY NIGHT AND THROUGH MUCH OF THE DAY ON THURSDAY.
THE ASSOCIATED ANTICYCLONIC VORTICITY BUBBLE IS SHOWN TO BE OVERHEAD
12Z THURSDAY BEFORE PASSING EASTWARD DURING THE MIDDAY PERIOD. THIS
WILL CAUSE THE REMNANT SURFACE RIDGING TO BEGIN RETREATING EASTWARD
BUT ALL SIGNS ARE IT WILL MAINTAIN CONTROL LOCALLY. IMPRESSIVE
SHORTWAVE IS FORECASTED TO SLIDE ALONG THE OHIO RIVER ON THURSDAY.
MODELS ARE UNAMINOUS IN KEEPING MEASURABLE PRECIPATION WELL SOUTH OF
THE OHIO-MICHIGAN STATELINE. ATTM...MODELS ARE ALSO SHOWING IT TO BE
A REAL STRUGGLE IN BRINGING THE HIGH CLOUD CANOPY THIS FAR
NORTHWARD. THERE IS A BIG DIFFERENCE BETWEEN THE NAM AND OTHER
SOLUTIONS...WITH THE NAM DEVELOPING A WEAK LOWER TROPOSPHERIC
FRONTAL BOUNDARY OVER THE NORTHERN CWA AS DIFFERENTIAL FLOW DEVELOPS
WITH A SECONDARY SURFACE HIGH NOSING SOUTHWARD DOWN NORTHERN LAKE
HURON. WITH ENHANCED CONVERGENCE ALONG THIS BOUNDARY THE NAM IS MORE
THAN WILLING TO PRODUCE PRECIPIATION ALONG IT BY THE AFTERNOON
HOURS. THERE IS A NON-ZERO POTENTIAL WITH SOME SUPPORT FROM VERY
WEAK BROAD MID TO UPPER LEVEL DEFORMATION FORCING. HOWEVER...
CONFIDENCE IS WAY TOO LOW TO JUMP ON THIS SOLUTION AND WILL MAINTAIN
A DRY FORECAST. ANY SATURATION WITHIN THE NAM BUFR SOUNDINGS IS FAR
FROM IMPRESSIVE. BUMPED HIGHS AGAIN UPWARD INTO THE UPPER 70S MOST
AREAS...COOLER AGAIN NEAR THE LAKESHORE.

MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THIS SETUP WILL YIELD SCATTERED SHOWERS AND A
FEW THUNDERSTORMS AGAIN TO MAINLY LAKE HURON THIS AFTERNOON AND
EVENING. A SECONDARY COLD FRONT WILL BRING SLIGHTLY STRONGER WINDS
WITH GUSTS IN THE 25 KNOT RANGE TODAY. WHILE THIS SYSTEM MAY BRING
CONDITIONS APPROACHING SMALL CRAFT ADVISORIES...THE DUE WESTERLY
TRAJECTORY WILL KEEP THE FETCH UNFAVORABLE FOR THE NEARSHORE AREAS
ALONG SOUTHEASTERN MICHIGAN. WINDS WILL THEN SLOWLY DECREASE ON
WEDNESDAY AS A HIGH PRESSURE SYSTEM APPROACHES WITH A LIGHT AND
VARIABLE WIND FIELD ON THURSDAY AS THIS HIGH BUILDS OVER THE REGION.

&&

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

$$

AVIATION.....SF
SHORT TERM...SF
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 040734
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
334 AM EDT TUE AUG 4 2015

.SHORT TERM...TODAY AND TONIGHT

DRIER LOW LEVEL AIR IN PLACE ACROSS SOUTHEAST MICHIGAN AS INDICATED
BY THE SURFACE DEW PTS IN THE 50S. HOWEVER...THE MID LEVELS ARE
SIGNIFICANTLY COLDER...WITH THE 00Z RAOB OUT OF GREEN BAY REPORTING
A 500 MB TEMP OF -17 C. THUS...WITH SOME SEMBLANCE OF SURFACE
TROUGH/COLD FRONT MOVING THROUGH CENTRAL LOWER MICHIGAN DURING PEAK
HEATING...ENOUGH INSTABILITY AND CAPE (UP TO 500 J/KG) TO GENERATE
SCATTERED SHOWERS TODAY...WITH EQL LEVELS EVEN POTENTIALLY SLIPPING
BY 20000 FEET TO GENERATE ISOLATED THUNDERSTORMS...WITH GREATEST
CONCENTRATION OF ACTIVITY ACROSS THE NORTHERN THUMB REGION. FARTHER
SOUTH TOWARD THE OHIO BORDER...MID LEVEL DRY AIR SEEN IN THE WATER
VAPOR IMAGERY AND 700 MB RH FIELDS SHOULD BE SUFFICIENT TO CAP
ACTIVITY...AND SUBSEQUENTLY SHOULD SEE HIGHS SNEAK BACK INTO THE
LOWER 80S FROM DETROIT SOUTH WITH 850 MB TEMPS UP AROUND 12 C.
COOLER 850 MB TEMPS FARTHER NORTH...COUPLED WITH THE ADDITIONAL
CLOUD COVERAGE AND SHOWERS SHOULD HOLD LOCATIONS NORTH OF M-59 IN
THE UPPER 70S. PRETTY GOOD LOW LEVEL COLD ADVECTION THIS
EVENING/TONIGHT WITH 925 MB TEMPS LOWERING INTO THE LOWER
TEENS...AND WITH SURFACE WINDS TRENDING TOWARD CALM...GOOD RADIATORS
SHOULD MAKE A RUN TOWARD 50 DEGREES...ASSUMING THERE IS LITTLE IN
THE WAY OF 5000-6000 KFT CLOUDS LINGERING WITH WEAK 850 MB
FGEN/BAROCLINIC ZONE...OTHERWISE MINS HOLDING IN THE 50S.

&&

.LONG TERM...

STRONG ANTICYCLONIC VORTICITY ADVECTION BACKED BY GEOPOTENTIAL
HEIGHT REBOUND WILL PROVIDE A PERFECT SETUP FOR STRONG SURFACE HIGH
PRESSURE OVER THE GREAT LAKES REGION ON WEDNESDAY. MODEL DATA
SUPPORTS THIS NOTION DEPICTING THE CENTER OF THE ANTICYCLONE
SHIFTING FROM THE LAKE MICHIGAN-SUPERIOR AGGREGATE TO THE LAKE
SUPERIOR-HURON AGGREGATE BY 00Z THURSDAY. EVEN THE MOIST-BIASED NAM
IS SHOWING A STRONGLY STABLE COLUMN WITH STRONG STABILITY BETWEEN 5
AND 20 KFT AGL. EXPECTING A HIGH AMOUNT OF INSOLATION AND
THUS...RAISED HIGHS SLIGHTLY WITH MID TO UPPER 70S LIKELY ACROSS
MUCH OF SEMICH. THE EXCEPTION...LOWER 70S...WILL IN BE THE NORTHERN
THUMB WHERE LOCALIZED WINDS OFF OF LAKE HURON WILL LIKELY CAUSE SOME
INLAND PENETRATION OF THE MARINE LAYER.

DAMPENING MIDLEVEL RIDGE AXIS WILL THEN WORK ACROSS SOUTHEASTERN
MICHIGAN WEDNESDAY NIGHT AND THROUGH MUCH OF THE DAY ON THURSDAY.
THE ASSOCIATED ANTICYCLONIC VORTICITY BUBBLE IS SHOWN TO BE OVERHEAD
12Z THURSDAY BEFORE PASSING EASTWARD DURING THE MIDDAY PERIOD. THIS
WILL CAUSE THE REMNANT SURFACE RIDGING TO BEGIN RETREATING EASTWARD
BUT ALL SIGNS ARE IT WILL MAINTAIN CONTROL LOCALLY. IMPRESSIVE
SHORTWAVE IS FORECASTED TO SLIDE ALONG THE OHIO RIVER ON THURSDAY.
MODELS ARE UNAMINOUS IN KEEPING MEASURABLE PRECIPATION WELL SOUTH OF
THE OHIO-MICHIGAN STATELINE. ATTM...MODELS ARE ALSO SHOWING IT TO BE
A REAL STRUGGLE IN BRINGING THE HIGH CLOUD CANOPY THIS FAR
NORTHWARD. THERE IS A BIG DIFFERENCE BETWEEN THE NAM AND OTHER
SOLUTIONS...WITH THE NAM DEVELOPING A WEAK LOWER TROPOSPHERIC
FRONTAL BOUNDARY OVER THE NORTHERN CWA AS DIFFERENTIAL FLOW DEVELOPS
WITH A SECONDARY SURFACE HIGH NOSING SOUTHWARD DOWN NORTHERN LAKE
HURON. WITH ENHANCED CONVERGENCE ALONG THIS BOUNDARY THE NAM IS MORE
THAN WILLING TO PRODUCE PRECIPIATION ALONG IT BY THE AFTERNOON
HOURS. THERE IS A NON-ZERO POTENTIAL WITH SOME SUPPORT FROM VERY
WEAK BROAD MID TO UPPER LEVEL DEFORMATION FORCING. HOWEVER...
CONFIDENCE IS WAY TOO LOW TO JUMP ON THIS SOLUTION AND WILL MAINTAIN
A DRY FORECAST. ANY SATURATION WITHIN THE NAM BUFR SOUNDINGS IS FAR
FROM IMPRESSIVE. BUMPED HIGHS AGAIN UPWARD INTO THE UPPER 70S MOST
AREAS...COOLER AGAIN NEAR THE LAKESHORE.

&&

.MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THIS SETUP WILL YIELD SCATTERED SHOWERS AND A
FEW THUNDERSTORMS AGAIN TO MAINLY LAKE HURON THIS AFTERNOON AND
EVENING. A SECONDARY COLD FRONT WILL BRING SLIGHTLY STRONGER WINDS
WITH GUSTS IN THE 25 KNOT RANGE TODAY. WHILE THIS SYSTEM MAY BRING
CONDITIONS APPROACHING SMALL CRAFT ADVISORIES...THE DUE WESTERLY
TRAJECTORY WILL KEEP THE FETCH UNFAVORABLE FOR THE NEARSHORE AREAS
ALONG SOUTHEASTERN MICHIGAN. WINDS WILL THEN SLOWLY DECREASE ON
WEDNESDAY AS A HIGH PRESSURE SYSTEM APPROACHES WITH A LIGHT AND
VARIABLE WIND FIELD ON THURSDAY AS THIS HIGH BUILDS OVER THE REGION.

&&

.AVIATION...ISSUED 1154 PM EDT MON AUG 3 2015

AN UPPER LEVEL DISTURBANCE TRACKING THROUGH THE NORTHERN GREAT LAKES
WILL DROP A WEAK COLD FRONT DOWN THROUGH CENTRAL AND SOUTHERN LOWER
MICHIGAN LATE TONIGHT AND EARLY TUESDAY. THIS WILL ALLOW MID-LEVEL
CLOUDS OVER THE NORTHERN HALF OF THE STATE TO GRADUALLY MAKE INROADS
SOUTH LATE TONIGHT. THE FRONT COMBINED WITH INCREASING INSTABILITY
DURING THE DAY WILL ALLOW SCATTERED SHOWERS AND PERHAPS A FEW
THUNDERSTORMS TO DEVELOP BY AFTERNOON. CHANCES LOOK BEST AT
MBS...WITH DECREASING POTENTIAL AS YOU WORK SOUTHWARD. GUSTY WEST
WINDS WILL ALSO DEVELOP TUESDAY AFTERNOON...WITH GUSTS TOPPING OUT
AROUND 20 KNOTS.

FOR DTW...A WEAK FRONTAL BOUNDARY DROPPING THROUGH THE AREA WILL
ALLOW CLOUD COVER TO INCREASE LATE TONIGHT INTO TUESDAY...WITH SKIES
BECOMING BKN NEAR 5000 FEET BY ABOUT 16Z. SHOWERS AND THUNDERSTORMS
THAT DEVELOP TOMORROW ARE EXPECTED TO REMAIN NORTH OF DTW.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

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

$$

SHORT TERM...SF
LONG TERM....CB
MARINE.......CB
AVIATION.....HLO


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




000
FXUS63 KDTX 040734
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
334 AM EDT TUE AUG 4 2015

.SHORT TERM...TODAY AND TONIGHT

DRIER LOW LEVEL AIR IN PLACE ACROSS SOUTHEAST MICHIGAN AS INDICATED
BY THE SURFACE DEW PTS IN THE 50S. HOWEVER...THE MID LEVELS ARE
SIGNIFICANTLY COLDER...WITH THE 00Z RAOB OUT OF GREEN BAY REPORTING
A 500 MB TEMP OF -17 C. THUS...WITH SOME SEMBLANCE OF SURFACE
TROUGH/COLD FRONT MOVING THROUGH CENTRAL LOWER MICHIGAN DURING PEAK
HEATING...ENOUGH INSTABILITY AND CAPE (UP TO 500 J/KG) TO GENERATE
SCATTERED SHOWERS TODAY...WITH EQL LEVELS EVEN POTENTIALLY SLIPPING
BY 20000 FEET TO GENERATE ISOLATED THUNDERSTORMS...WITH GREATEST
CONCENTRATION OF ACTIVITY ACROSS THE NORTHERN THUMB REGION. FARTHER
SOUTH TOWARD THE OHIO BORDER...MID LEVEL DRY AIR SEEN IN THE WATER
VAPOR IMAGERY AND 700 MB RH FIELDS SHOULD BE SUFFICIENT TO CAP
ACTIVITY...AND SUBSEQUENTLY SHOULD SEE HIGHS SNEAK BACK INTO THE
LOWER 80S FROM DETROIT SOUTH WITH 850 MB TEMPS UP AROUND 12 C.
COOLER 850 MB TEMPS FARTHER NORTH...COUPLED WITH THE ADDITIONAL
CLOUD COVERAGE AND SHOWERS SHOULD HOLD LOCATIONS NORTH OF M-59 IN
THE UPPER 70S. PRETTY GOOD LOW LEVEL COLD ADVECTION THIS
EVENING/TONIGHT WITH 925 MB TEMPS LOWERING INTO THE LOWER
TEENS...AND WITH SURFACE WINDS TRENDING TOWARD CALM...GOOD RADIATORS
SHOULD MAKE A RUN TOWARD 50 DEGREES...ASSUMING THERE IS LITTLE IN
THE WAY OF 5000-6000 KFT CLOUDS LINGERING WITH WEAK 850 MB
FGEN/BAROCLINIC ZONE...OTHERWISE MINS HOLDING IN THE 50S.

&&

.LONG TERM...

STRONG ANTICYCLONIC VORTICITY ADVECTION BACKED BY GEOPOTENTIAL
HEIGHT REBOUND WILL PROVIDE A PERFECT SETUP FOR STRONG SURFACE HIGH
PRESSURE OVER THE GREAT LAKES REGION ON WEDNESDAY. MODEL DATA
SUPPORTS THIS NOTION DEPICTING THE CENTER OF THE ANTICYCLONE
SHIFTING FROM THE LAKE MICHIGAN-SUPERIOR AGGREGATE TO THE LAKE
SUPERIOR-HURON AGGREGATE BY 00Z THURSDAY. EVEN THE MOIST-BIASED NAM
IS SHOWING A STRONGLY STABLE COLUMN WITH STRONG STABILITY BETWEEN 5
AND 20 KFT AGL. EXPECTING A HIGH AMOUNT OF INSOLATION AND
THUS...RAISED HIGHS SLIGHTLY WITH MID TO UPPER 70S LIKELY ACROSS
MUCH OF SEMICH. THE EXCEPTION...LOWER 70S...WILL IN BE THE NORTHERN
THUMB WHERE LOCALIZED WINDS OFF OF LAKE HURON WILL LIKELY CAUSE SOME
INLAND PENETRATION OF THE MARINE LAYER.

DAMPENING MIDLEVEL RIDGE AXIS WILL THEN WORK ACROSS SOUTHEASTERN
MICHIGAN WEDNESDAY NIGHT AND THROUGH MUCH OF THE DAY ON THURSDAY.
THE ASSOCIATED ANTICYCLONIC VORTICITY BUBBLE IS SHOWN TO BE OVERHEAD
12Z THURSDAY BEFORE PASSING EASTWARD DURING THE MIDDAY PERIOD. THIS
WILL CAUSE THE REMNANT SURFACE RIDGING TO BEGIN RETREATING EASTWARD
BUT ALL SIGNS ARE IT WILL MAINTAIN CONTROL LOCALLY. IMPRESSIVE
SHORTWAVE IS FORECASTED TO SLIDE ALONG THE OHIO RIVER ON THURSDAY.
MODELS ARE UNAMINOUS IN KEEPING MEASURABLE PRECIPATION WELL SOUTH OF
THE OHIO-MICHIGAN STATELINE. ATTM...MODELS ARE ALSO SHOWING IT TO BE
A REAL STRUGGLE IN BRINGING THE HIGH CLOUD CANOPY THIS FAR
NORTHWARD. THERE IS A BIG DIFFERENCE BETWEEN THE NAM AND OTHER
SOLUTIONS...WITH THE NAM DEVELOPING A WEAK LOWER TROPOSPHERIC
FRONTAL BOUNDARY OVER THE NORTHERN CWA AS DIFFERENTIAL FLOW DEVELOPS
WITH A SECONDARY SURFACE HIGH NOSING SOUTHWARD DOWN NORTHERN LAKE
HURON. WITH ENHANCED CONVERGENCE ALONG THIS BOUNDARY THE NAM IS MORE
THAN WILLING TO PRODUCE PRECIPIATION ALONG IT BY THE AFTERNOON
HOURS. THERE IS A NON-ZERO POTENTIAL WITH SOME SUPPORT FROM VERY
WEAK BROAD MID TO UPPER LEVEL DEFORMATION FORCING. HOWEVER...
CONFIDENCE IS WAY TOO LOW TO JUMP ON THIS SOLUTION AND WILL MAINTAIN
A DRY FORECAST. ANY SATURATION WITHIN THE NAM BUFR SOUNDINGS IS FAR
FROM IMPRESSIVE. BUMPED HIGHS AGAIN UPWARD INTO THE UPPER 70S MOST
AREAS...COOLER AGAIN NEAR THE LAKESHORE.

&&

.MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THIS SETUP WILL YIELD SCATTERED SHOWERS AND A
FEW THUNDERSTORMS AGAIN TO MAINLY LAKE HURON THIS AFTERNOON AND
EVENING. A SECONDARY COLD FRONT WILL BRING SLIGHTLY STRONGER WINDS
WITH GUSTS IN THE 25 KNOT RANGE TODAY. WHILE THIS SYSTEM MAY BRING
CONDITIONS APPROACHING SMALL CRAFT ADVISORIES...THE DUE WESTERLY
TRAJECTORY WILL KEEP THE FETCH UNFAVORABLE FOR THE NEARSHORE AREAS
ALONG SOUTHEASTERN MICHIGAN. WINDS WILL THEN SLOWLY DECREASE ON
WEDNESDAY AS A HIGH PRESSURE SYSTEM APPROACHES WITH A LIGHT AND
VARIABLE WIND FIELD ON THURSDAY AS THIS HIGH BUILDS OVER THE REGION.

&&

.AVIATION...ISSUED 1154 PM EDT MON AUG 3 2015

AN UPPER LEVEL DISTURBANCE TRACKING THROUGH THE NORTHERN GREAT LAKES
WILL DROP A WEAK COLD FRONT DOWN THROUGH CENTRAL AND SOUTHERN LOWER
MICHIGAN LATE TONIGHT AND EARLY TUESDAY. THIS WILL ALLOW MID-LEVEL
CLOUDS OVER THE NORTHERN HALF OF THE STATE TO GRADUALLY MAKE INROADS
SOUTH LATE TONIGHT. THE FRONT COMBINED WITH INCREASING INSTABILITY
DURING THE DAY WILL ALLOW SCATTERED SHOWERS AND PERHAPS A FEW
THUNDERSTORMS TO DEVELOP BY AFTERNOON. CHANCES LOOK BEST AT
MBS...WITH DECREASING POTENTIAL AS YOU WORK SOUTHWARD. GUSTY WEST
WINDS WILL ALSO DEVELOP TUESDAY AFTERNOON...WITH GUSTS TOPPING OUT
AROUND 20 KNOTS.

FOR DTW...A WEAK FRONTAL BOUNDARY DROPPING THROUGH THE AREA WILL
ALLOW CLOUD COVER TO INCREASE LATE TONIGHT INTO TUESDAY...WITH SKIES
BECOMING BKN NEAR 5000 FEET BY ABOUT 16Z. SHOWERS AND THUNDERSTORMS
THAT DEVELOP TOMORROW ARE EXPECTED TO REMAIN NORTH OF DTW.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

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

$$

SHORT TERM...SF
LONG TERM....CB
MARINE.......CB
AVIATION.....HLO


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





000
FXUS63 KDTX 040354
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1154 PM EDT MON AUG 3 2015


.AVIATION...

AN UPPER LEVEL DISTURBANCE TRACKING THROUGH THE NORTHERN GREAT LAKES
WILL DROP A WEAK COLD FRONT DOWN THROUGH CENTRAL AND SOUTHERN LOWER
MICHIGAN LATE TONIGHT AND EARLY TUESDAY. THIS WILL ALLOW MID-LEVEL
CLOUDS OVER THE NORTHERN HALF OF THE STATE TO GRADUALLY MAKE INROADS
SOUTH LATE TONIGHT. THE FRONT COMBINED WITH INCREASING INSTABILITY
DURING THE DAY WILL ALLOW SCATTERED SHOWERS AND PERHAPS A FEW
THUNDERSTORMS TO DEVELOP BY AFTERNOON. CHANCES LOOK BEST AT
MBS...WITH DECREASING POTENTIAL AS YOU WORK SOUTHWARD. GUSTY WEST
WINDS WILL ALSO DEVELOP TUESDAY AFTERNOON...WITH GUSTS TOPPING OUT
AROUND 20 KNOTS.

FOR DTW...A WEAK FRONTAL BOUNDARY DROPPING THROUGH THE AREA WILL
ALLOW CLOUD COVER TO INCREASE LATE TONIGHT INTO TUESDAY...WITH SKIES
BECOMING BKN NEAR 5000 FEET BY ABOUT 16Z. SHOWERS AND THUNDERSTORMS
THAT DEVELOP TOMORROW ARE EXPECTED TO REMAIN NORTH OF DTW.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

.PREV DISCUSSION...ISSUED 344 PM EDT MON AUG 3 2015

SHORT TERM...THIS EVENING THROUGH TONIGHT

A SECONDARY COLD FRONTAL TROUGH SWINGING THROUGH LOWER MI TODAY
PRODUCED ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND
THUNDERSTORMS...WHICH WILL WANE INTO THE EVENING HOURS. THE PRE-
FRONTAL AIRMASS WAS ABLE TO REACH INTO THE UPPER 70S/LOW 80S WITH
LOW 60 DEWPOINTS...COMBINED WITH FAVORABLE LOW/MID LEVEL LAPSE RATES
AIDED BY CAA ALOFT AND THE FRONTAL FORCING WAS ABLE TO PRODUCE SOME
WEAK THUNDERSTORMS. THE SFC FRONT IS NOW EXTENDING ALONG A LINE FROM
BAX TO JACKSON AND WILL CONTINUE EASTWARD...EXITING SE MI THIS
EVENING...LEAVING A DRIER FORECAST IN ITS WAKE. CLOUD TRENDS THIS
EVENING AND OVERNIGHT ARE LOOKING A BIT TRICKIER. MUCH DRIER
DEWPOINTS IN THE LOW 50S...EVEN A FEW 40S NOTED IN MID MI...BEHIND
THE FRONT WILL TRY TO DRY THE COLUMN OUT QUICKLY...BUT VISIBLE
SATELLITE SHOWS A ROBUST CLOUD FIELD WITHIN THE DEEP CYCLONIC FLOW
WHICH WILL DROP SOUTH AND EAST AND SHOULD IMPACT LOCATIONS NORTH OF
I69 THROUGH MOST OF THE NIGHT. SO WE WILL LIKELY HAVE A GRADIENT OF
CLEAR TO MOSTLY CLOUDS SET UP ACROSS OUT CWA AND HAVE HEDGED THE
FORECAST ACCORDINGLY.

LONG TERM...

ANOTHER VIGOROUS SPOKE OF SHORTWAVE ENERGY IS DUE INTO THE AREA ON
TUESDAY AS STRONG UPPER LOW PRESSURE REMAINS CENTERED NEAR JAMES BAY
FOR ANOTHER DAY. MUCH LIKE TODAY...EXPECT AN EXPANDING AREA OF
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS AS ENHANCED LIFT
FROM THIS WAVE COINCIDES WITH DAYTIME INSTABILITY MAXIMUM. WITH THE
OVERALL UPPER TROUGH AXIS SLOWLY EDGING EASTWARD DURING THIS TIME
FRAME...EXPECT THE BEST CONCENTRATION OF THIS CONVECTION TO OCCUR
OVER LAKE HURON/THUMB REGION WITH A STEADILY DIMINISHING CHANCE OF
RAINFALL SOUTHWEST FROM THERE. WITH NEUTRAL TO WEAK WARM AIR
ADVECTION BACK INTO AREA IN ADVANCE OF THIS WAVE...TEMPERATURES WILL
REMAIN MILD WITH UPPER 70S TO LOWER 80S COMMON FOR HIGH TEMPERATURES
DURING THE AFTERNOON. A SLIGHTLY DOWNSLOPING FLOW INTO METRO DETROIT
WILL MOST LIKELY GARNER A TEMPERATURE AROUND 83F.

SHOWER ACTIVITY WILL WANE QUICKLY IN THE EARLY EVENING AS LIFT FROM
THE SHORTWAVE SHIFTS EAST AND DAYTIME INSTABILITY IS LOST. WITH THE
COOLER AIRMASS SETTLING INTO THE AREA...EXPECT COOL READINGS TUESDAY
NIGHT WITH LOW TEMPERATURES DOWN INTO THE 50S IN MOST LOCATIONS AND
PROBABLY RIGHT AROUND 50F IN SOME LOCATIONS ALONG THE NORTH OF ABOUT
THE I-69 CORRIDOR. THESE COOL TEMPERATURES WILL PERSIST INTO THE
MIDDLE OF THE WEEK AS CANADIAN HIGH PRESSURE BUILDS INTO AREA WITHIN
NORTHWEST FLOW REGIME. HIGHS WEDNESDAY WILL HOLD IN THE LOWER/MID
70S WITH LOWS BACK INTO THE 50S WEDNESDAY NIGHT. WITH THIS HIGH IN
PLACE...DRY WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT.

THURSDAY THROUGH MONDAY.

MODELS APPEAR TO BE IN HIGH DISAGREEMENT WITH THURSDAY`S WEATHER
SCENARIO...WHICH LENDS LOW CONFIDENCE TO PRETTY MUCH ALL OF THE
EXTENDED PERIOD. WEDNESDAY IS STILL FAVORING HIGH PRESSURE AND DRY
CONDITIONS...SO WILL CONTINUE TO FOLLOW YESTERDAY`S THINKING AND
HOLD OVER DRY CONDITIONS FOR MOST OF SOUTHEAST MICHIGAN ON THURSDAY
MORNING. THE EXCEPTION WILL REMAIN THE SOUTHERN MOST COUNTIES WHERE
SCATTERED SHOWERS WILL BEGIN EDGING INTO THE CWA PRIOR TO 8AM. WILL
ALSO KEEP SHOWERS EXPANDING INTO THE CWA THROUGH THE AFTERNOON AND
EVENING. AT LEAST A SLIGHT CHANCE OF SHOWERS IS FAVORED THROUGH THE
WEEKEND. MID 70 DEGREE HIGHS ANTICIPATED THROUGH SATURDAY WITH HIGH
TEMPS NUDGING INTO THE UPPER 70S BY SUNDAY.

MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THESE SYSTEMS WILL ALSO BRING SCATTERED SHOWERS
AND A FEW THUNDERSTORMS TO MAINLY LAKE HURON TODAY AND AGAIN TUESDAY
AFTERNOON AND EVENING.

THE FIRST SUCH FRONT WILL BRING GUSTS OVER PARTS OF THE LAKE HURON
OPEN WATERS TO 20 KNOTS OR A BIT MORE THIS EVENING...WITH A SECOND
FRONT BRINGING SLIGHTLY STRONGER WINDS OVERNIGHT TUESDAY NIGHT WITH
GUSTS IN THE 25 KNOT AREA. WHILE THIS SYSTEM MAY BRING CONDITIONS
APPROACHING SMALL CRAFT ADVISORIES...THE NORTHWEST TRAJECTORY WILL

WINDS WILL THEN SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE
SYSTEM APPROACHES WITH A LIGHT AND VARIABLE WIND FIELD ON THURSDAY
AS THIS HIGH BUILDS OVER THE REGION.

&&

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

$$

AVIATION.....HLO
SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG


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




000
FXUS63 KDTX 040354
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1154 PM EDT MON AUG 3 2015


.AVIATION...

AN UPPER LEVEL DISTURBANCE TRACKING THROUGH THE NORTHERN GREAT LAKES
WILL DROP A WEAK COLD FRONT DOWN THROUGH CENTRAL AND SOUTHERN LOWER
MICHIGAN LATE TONIGHT AND EARLY TUESDAY. THIS WILL ALLOW MID-LEVEL
CLOUDS OVER THE NORTHERN HALF OF THE STATE TO GRADUALLY MAKE INROADS
SOUTH LATE TONIGHT. THE FRONT COMBINED WITH INCREASING INSTABILITY
DURING THE DAY WILL ALLOW SCATTERED SHOWERS AND PERHAPS A FEW
THUNDERSTORMS TO DEVELOP BY AFTERNOON. CHANCES LOOK BEST AT
MBS...WITH DECREASING POTENTIAL AS YOU WORK SOUTHWARD. GUSTY WEST
WINDS WILL ALSO DEVELOP TUESDAY AFTERNOON...WITH GUSTS TOPPING OUT
AROUND 20 KNOTS.

FOR DTW...A WEAK FRONTAL BOUNDARY DROPPING THROUGH THE AREA WILL
ALLOW CLOUD COVER TO INCREASE LATE TONIGHT INTO TUESDAY...WITH SKIES
BECOMING BKN NEAR 5000 FEET BY ABOUT 16Z. SHOWERS AND THUNDERSTORMS
THAT DEVELOP TOMORROW ARE EXPECTED TO REMAIN NORTH OF DTW.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

.PREV DISCUSSION...ISSUED 344 PM EDT MON AUG 3 2015

SHORT TERM...THIS EVENING THROUGH TONIGHT

A SECONDARY COLD FRONTAL TROUGH SWINGING THROUGH LOWER MI TODAY
PRODUCED ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND
THUNDERSTORMS...WHICH WILL WANE INTO THE EVENING HOURS. THE PRE-
FRONTAL AIRMASS WAS ABLE TO REACH INTO THE UPPER 70S/LOW 80S WITH
LOW 60 DEWPOINTS...COMBINED WITH FAVORABLE LOW/MID LEVEL LAPSE RATES
AIDED BY CAA ALOFT AND THE FRONTAL FORCING WAS ABLE TO PRODUCE SOME
WEAK THUNDERSTORMS. THE SFC FRONT IS NOW EXTENDING ALONG A LINE FROM
BAX TO JACKSON AND WILL CONTINUE EASTWARD...EXITING SE MI THIS
EVENING...LEAVING A DRIER FORECAST IN ITS WAKE. CLOUD TRENDS THIS
EVENING AND OVERNIGHT ARE LOOKING A BIT TRICKIER. MUCH DRIER
DEWPOINTS IN THE LOW 50S...EVEN A FEW 40S NOTED IN MID MI...BEHIND
THE FRONT WILL TRY TO DRY THE COLUMN OUT QUICKLY...BUT VISIBLE
SATELLITE SHOWS A ROBUST CLOUD FIELD WITHIN THE DEEP CYCLONIC FLOW
WHICH WILL DROP SOUTH AND EAST AND SHOULD IMPACT LOCATIONS NORTH OF
I69 THROUGH MOST OF THE NIGHT. SO WE WILL LIKELY HAVE A GRADIENT OF
CLEAR TO MOSTLY CLOUDS SET UP ACROSS OUT CWA AND HAVE HEDGED THE
FORECAST ACCORDINGLY.

LONG TERM...

ANOTHER VIGOROUS SPOKE OF SHORTWAVE ENERGY IS DUE INTO THE AREA ON
TUESDAY AS STRONG UPPER LOW PRESSURE REMAINS CENTERED NEAR JAMES BAY
FOR ANOTHER DAY. MUCH LIKE TODAY...EXPECT AN EXPANDING AREA OF
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS AS ENHANCED LIFT
FROM THIS WAVE COINCIDES WITH DAYTIME INSTABILITY MAXIMUM. WITH THE
OVERALL UPPER TROUGH AXIS SLOWLY EDGING EASTWARD DURING THIS TIME
FRAME...EXPECT THE BEST CONCENTRATION OF THIS CONVECTION TO OCCUR
OVER LAKE HURON/THUMB REGION WITH A STEADILY DIMINISHING CHANCE OF
RAINFALL SOUTHWEST FROM THERE. WITH NEUTRAL TO WEAK WARM AIR
ADVECTION BACK INTO AREA IN ADVANCE OF THIS WAVE...TEMPERATURES WILL
REMAIN MILD WITH UPPER 70S TO LOWER 80S COMMON FOR HIGH TEMPERATURES
DURING THE AFTERNOON. A SLIGHTLY DOWNSLOPING FLOW INTO METRO DETROIT
WILL MOST LIKELY GARNER A TEMPERATURE AROUND 83F.

SHOWER ACTIVITY WILL WANE QUICKLY IN THE EARLY EVENING AS LIFT FROM
THE SHORTWAVE SHIFTS EAST AND DAYTIME INSTABILITY IS LOST. WITH THE
COOLER AIRMASS SETTLING INTO THE AREA...EXPECT COOL READINGS TUESDAY
NIGHT WITH LOW TEMPERATURES DOWN INTO THE 50S IN MOST LOCATIONS AND
PROBABLY RIGHT AROUND 50F IN SOME LOCATIONS ALONG THE NORTH OF ABOUT
THE I-69 CORRIDOR. THESE COOL TEMPERATURES WILL PERSIST INTO THE
MIDDLE OF THE WEEK AS CANADIAN HIGH PRESSURE BUILDS INTO AREA WITHIN
NORTHWEST FLOW REGIME. HIGHS WEDNESDAY WILL HOLD IN THE LOWER/MID
70S WITH LOWS BACK INTO THE 50S WEDNESDAY NIGHT. WITH THIS HIGH IN
PLACE...DRY WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT.

THURSDAY THROUGH MONDAY.

MODELS APPEAR TO BE IN HIGH DISAGREEMENT WITH THURSDAY`S WEATHER
SCENARIO...WHICH LENDS LOW CONFIDENCE TO PRETTY MUCH ALL OF THE
EXTENDED PERIOD. WEDNESDAY IS STILL FAVORING HIGH PRESSURE AND DRY
CONDITIONS...SO WILL CONTINUE TO FOLLOW YESTERDAY`S THINKING AND
HOLD OVER DRY CONDITIONS FOR MOST OF SOUTHEAST MICHIGAN ON THURSDAY
MORNING. THE EXCEPTION WILL REMAIN THE SOUTHERN MOST COUNTIES WHERE
SCATTERED SHOWERS WILL BEGIN EDGING INTO THE CWA PRIOR TO 8AM. WILL
ALSO KEEP SHOWERS EXPANDING INTO THE CWA THROUGH THE AFTERNOON AND
EVENING. AT LEAST A SLIGHT CHANCE OF SHOWERS IS FAVORED THROUGH THE
WEEKEND. MID 70 DEGREE HIGHS ANTICIPATED THROUGH SATURDAY WITH HIGH
TEMPS NUDGING INTO THE UPPER 70S BY SUNDAY.

MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THESE SYSTEMS WILL ALSO BRING SCATTERED SHOWERS
AND A FEW THUNDERSTORMS TO MAINLY LAKE HURON TODAY AND AGAIN TUESDAY
AFTERNOON AND EVENING.

THE FIRST SUCH FRONT WILL BRING GUSTS OVER PARTS OF THE LAKE HURON
OPEN WATERS TO 20 KNOTS OR A BIT MORE THIS EVENING...WITH A SECOND
FRONT BRINGING SLIGHTLY STRONGER WINDS OVERNIGHT TUESDAY NIGHT WITH
GUSTS IN THE 25 KNOT AREA. WHILE THIS SYSTEM MAY BRING CONDITIONS
APPROACHING SMALL CRAFT ADVISORIES...THE NORTHWEST TRAJECTORY WILL

WINDS WILL THEN SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE
SYSTEM APPROACHES WITH A LIGHT AND VARIABLE WIND FIELD ON THURSDAY
AS THIS HIGH BUILDS OVER THE REGION.

&&

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

$$

AVIATION.....HLO
SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG


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




000
FXUS63 KDTX 040354
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1154 PM EDT MON AUG 3 2015


.AVIATION...

AN UPPER LEVEL DISTURBANCE TRACKING THROUGH THE NORTHERN GREAT LAKES
WILL DROP A WEAK COLD FRONT DOWN THROUGH CENTRAL AND SOUTHERN LOWER
MICHIGAN LATE TONIGHT AND EARLY TUESDAY. THIS WILL ALLOW MID-LEVEL
CLOUDS OVER THE NORTHERN HALF OF THE STATE TO GRADUALLY MAKE INROADS
SOUTH LATE TONIGHT. THE FRONT COMBINED WITH INCREASING INSTABILITY
DURING THE DAY WILL ALLOW SCATTERED SHOWERS AND PERHAPS A FEW
THUNDERSTORMS TO DEVELOP BY AFTERNOON. CHANCES LOOK BEST AT
MBS...WITH DECREASING POTENTIAL AS YOU WORK SOUTHWARD. GUSTY WEST
WINDS WILL ALSO DEVELOP TUESDAY AFTERNOON...WITH GUSTS TOPPING OUT
AROUND 20 KNOTS.

FOR DTW...A WEAK FRONTAL BOUNDARY DROPPING THROUGH THE AREA WILL
ALLOW CLOUD COVER TO INCREASE LATE TONIGHT INTO TUESDAY...WITH SKIES
BECOMING BKN NEAR 5000 FEET BY ABOUT 16Z. SHOWERS AND THUNDERSTORMS
THAT DEVELOP TOMORROW ARE EXPECTED TO REMAIN NORTH OF DTW.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

.PREV DISCUSSION...ISSUED 344 PM EDT MON AUG 3 2015

SHORT TERM...THIS EVENING THROUGH TONIGHT

A SECONDARY COLD FRONTAL TROUGH SWINGING THROUGH LOWER MI TODAY
PRODUCED ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND
THUNDERSTORMS...WHICH WILL WANE INTO THE EVENING HOURS. THE PRE-
FRONTAL AIRMASS WAS ABLE TO REACH INTO THE UPPER 70S/LOW 80S WITH
LOW 60 DEWPOINTS...COMBINED WITH FAVORABLE LOW/MID LEVEL LAPSE RATES
AIDED BY CAA ALOFT AND THE FRONTAL FORCING WAS ABLE TO PRODUCE SOME
WEAK THUNDERSTORMS. THE SFC FRONT IS NOW EXTENDING ALONG A LINE FROM
BAX TO JACKSON AND WILL CONTINUE EASTWARD...EXITING SE MI THIS
EVENING...LEAVING A DRIER FORECAST IN ITS WAKE. CLOUD TRENDS THIS
EVENING AND OVERNIGHT ARE LOOKING A BIT TRICKIER. MUCH DRIER
DEWPOINTS IN THE LOW 50S...EVEN A FEW 40S NOTED IN MID MI...BEHIND
THE FRONT WILL TRY TO DRY THE COLUMN OUT QUICKLY...BUT VISIBLE
SATELLITE SHOWS A ROBUST CLOUD FIELD WITHIN THE DEEP CYCLONIC FLOW
WHICH WILL DROP SOUTH AND EAST AND SHOULD IMPACT LOCATIONS NORTH OF
I69 THROUGH MOST OF THE NIGHT. SO WE WILL LIKELY HAVE A GRADIENT OF
CLEAR TO MOSTLY CLOUDS SET UP ACROSS OUT CWA AND HAVE HEDGED THE
FORECAST ACCORDINGLY.

LONG TERM...

ANOTHER VIGOROUS SPOKE OF SHORTWAVE ENERGY IS DUE INTO THE AREA ON
TUESDAY AS STRONG UPPER LOW PRESSURE REMAINS CENTERED NEAR JAMES BAY
FOR ANOTHER DAY. MUCH LIKE TODAY...EXPECT AN EXPANDING AREA OF
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS AS ENHANCED LIFT
FROM THIS WAVE COINCIDES WITH DAYTIME INSTABILITY MAXIMUM. WITH THE
OVERALL UPPER TROUGH AXIS SLOWLY EDGING EASTWARD DURING THIS TIME
FRAME...EXPECT THE BEST CONCENTRATION OF THIS CONVECTION TO OCCUR
OVER LAKE HURON/THUMB REGION WITH A STEADILY DIMINISHING CHANCE OF
RAINFALL SOUTHWEST FROM THERE. WITH NEUTRAL TO WEAK WARM AIR
ADVECTION BACK INTO AREA IN ADVANCE OF THIS WAVE...TEMPERATURES WILL
REMAIN MILD WITH UPPER 70S TO LOWER 80S COMMON FOR HIGH TEMPERATURES
DURING THE AFTERNOON. A SLIGHTLY DOWNSLOPING FLOW INTO METRO DETROIT
WILL MOST LIKELY GARNER A TEMPERATURE AROUND 83F.

SHOWER ACTIVITY WILL WANE QUICKLY IN THE EARLY EVENING AS LIFT FROM
THE SHORTWAVE SHIFTS EAST AND DAYTIME INSTABILITY IS LOST. WITH THE
COOLER AIRMASS SETTLING INTO THE AREA...EXPECT COOL READINGS TUESDAY
NIGHT WITH LOW TEMPERATURES DOWN INTO THE 50S IN MOST LOCATIONS AND
PROBABLY RIGHT AROUND 50F IN SOME LOCATIONS ALONG THE NORTH OF ABOUT
THE I-69 CORRIDOR. THESE COOL TEMPERATURES WILL PERSIST INTO THE
MIDDLE OF THE WEEK AS CANADIAN HIGH PRESSURE BUILDS INTO AREA WITHIN
NORTHWEST FLOW REGIME. HIGHS WEDNESDAY WILL HOLD IN THE LOWER/MID
70S WITH LOWS BACK INTO THE 50S WEDNESDAY NIGHT. WITH THIS HIGH IN
PLACE...DRY WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT.

THURSDAY THROUGH MONDAY.

MODELS APPEAR TO BE IN HIGH DISAGREEMENT WITH THURSDAY`S WEATHER
SCENARIO...WHICH LENDS LOW CONFIDENCE TO PRETTY MUCH ALL OF THE
EXTENDED PERIOD. WEDNESDAY IS STILL FAVORING HIGH PRESSURE AND DRY
CONDITIONS...SO WILL CONTINUE TO FOLLOW YESTERDAY`S THINKING AND
HOLD OVER DRY CONDITIONS FOR MOST OF SOUTHEAST MICHIGAN ON THURSDAY
MORNING. THE EXCEPTION WILL REMAIN THE SOUTHERN MOST COUNTIES WHERE
SCATTERED SHOWERS WILL BEGIN EDGING INTO THE CWA PRIOR TO 8AM. WILL
ALSO KEEP SHOWERS EXPANDING INTO THE CWA THROUGH THE AFTERNOON AND
EVENING. AT LEAST A SLIGHT CHANCE OF SHOWERS IS FAVORED THROUGH THE
WEEKEND. MID 70 DEGREE HIGHS ANTICIPATED THROUGH SATURDAY WITH HIGH
TEMPS NUDGING INTO THE UPPER 70S BY SUNDAY.

MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THESE SYSTEMS WILL ALSO BRING SCATTERED SHOWERS
AND A FEW THUNDERSTORMS TO MAINLY LAKE HURON TODAY AND AGAIN TUESDAY
AFTERNOON AND EVENING.

THE FIRST SUCH FRONT WILL BRING GUSTS OVER PARTS OF THE LAKE HURON
OPEN WATERS TO 20 KNOTS OR A BIT MORE THIS EVENING...WITH A SECOND
FRONT BRINGING SLIGHTLY STRONGER WINDS OVERNIGHT TUESDAY NIGHT WITH
GUSTS IN THE 25 KNOT AREA. WHILE THIS SYSTEM MAY BRING CONDITIONS
APPROACHING SMALL CRAFT ADVISORIES...THE NORTHWEST TRAJECTORY WILL

WINDS WILL THEN SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE
SYSTEM APPROACHES WITH A LIGHT AND VARIABLE WIND FIELD ON THURSDAY
AS THIS HIGH BUILDS OVER THE REGION.

&&

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

$$

AVIATION.....HLO
SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG


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





000
FXUS63 KDTX 032349
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
749 PM EDT MON AUG 3 2015


.AVIATION...

SKIES WILL CLEAR FROM PTK SOUTH AS WE LOSE DAYTIME HEATING. FURTHER
NORTH...THE APPROACH OF ANOTHER UPPER LEVEL DISTURBANCE WILL KEEP
CLOUDS AROUND THROUGH THE NIGHTTIME HOURS. A WEAK FRONTAL BOUNDARY
WILL DROP THROUGH THE AREA TUESDAY...TRIGGERING SHOWERS AND A FEW
THUNDERSTORMS AS DAYTIME HEATING INCREASES INSTABILITY. BEST
POTENTIAL TO SEE A SHOWER/TSTORM WILL BE AT MBS...HOWEVER COVERAGE
LOOKS LOW ENOUGH AT THIS TIME TO PRECLUDE A MENTION IN THE TAFS.

FOR DTW...SHOWERS AND THUNDERSTORM ACTIVITY HAS ENDED FOR SOUTHERN
LOWER MICHIGAN...AND EXPECTING A QUIET NIGHT. SKIES WILL BE MOSTLY
CLEAR AS DAYTIME HEATING ALLOWS DAYTIME CU TO DISSIPATE. A WEAK
FRONTAL BOUNDARY DROPPING THROUGH THE AREA WILL ALLOW CLOUD COVER TO
INCREASE ONCE AGAIN ON TUESDAY...WITH SKIES BECOMING BKN NEAR 5000
FEET BY ABOUT 16Z. SHOWERS AND THUNDERSTORMS THAT DEVELOP TOMORROW
ARE EXPECTED TO REMAIN NORTH OF DTW.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

.PREV DISCUSSION...ISSUED 344 PM EDT MON AUG 3 2015

SHORT TERM...THIS EVENING THROUGH TONIGHT

A SECONDARY COLD FRONTAL TROUGH SWINGING THROUGH LOWER MI TODAY
PRODUCED ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND
THUNDERSTORMS...WHICH WILL WANE INTO THE EVENING HOURS. THE PRE-
FRONTAL AIRMASS WAS ABLE TO REACH INTO THE UPPER 70S/LOW 80S WITH
LOW 60 DEWPOINTS...COMBINED WITH FAVORABLE LOW/MID LEVEL LAPSE RATES
AIDED BY CAA ALOFT AND THE FRONTAL FORCING WAS ABLE TO PRODUCE SOME
WEAK THUNDERSTORMS. THE SFC FRONT IS NOW EXTENDING ALONG A LINE FROM
BAX TO JACKSON AND WILL CONTINUE EASTWARD...EXITING SE MI THIS
EVENING...LEAVING A DRIER FORECAST IN ITS WAKE. CLOUD TRENDS THIS
EVENING AND OVERNIGHT ARE LOOKING A BIT TRICKIER. MUCH DRIER
DEWPOINTS IN THE LOW 50S...EVEN A FEW 40S NOTED IN MID MI...BEHIND
THE FRONT WILL TRY TO DRY THE COLUMN OUT QUICKLY...BUT VISIBLE
SATELLITE SHOWS A ROBUST CLOUD FIELD WITHIN THE DEEP CYCLONIC FLOW
WHICH WILL DROP SOUTH AND EAST AND SHOULD IMPACT LOCATIONS NORTH OF
I69 THROUGH MOST OF THE NIGHT. SO WE WILL LIKELY HAVE A GRADIENT OF
CLEAR TO MOSTLY CLOUDS SET UP ACROSS OUT CWA AND HAVE HEDGED THE
FORECAST ACCORDINGLY.

LONG TERM...

ANOTHER VIGOROUS SPOKE OF SHORTWAVE ENERGY IS DUE INTO THE AREA ON
TUESDAY AS STRONG UPPER LOW PRESSURE REMAINS CENTERED NEAR JAMES BAY
FOR ANOTHER DAY. MUCH LIKE TODAY...EXPECT AN EXPANDING AREA OF
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS AS ENHANCED LIFT
FROM THIS WAVE COINCIDES WITH DAYTIME INSTABILITY MAXIMUM. WITH THE
OVERALL UPPER TROUGH AXIS SLOWLY EDGING EASTWARD DURING THIS TIME
FRAME...EXPECT THE BEST CONCENTRATION OF THIS CONVECTION TO OCCUR
OVER LAKE HURON/THUMB REGION WITH A STEADILY DIMINISHING CHANCE OF
RAINFALL SOUTHWEST FROM THERE. WITH NEUTRAL TO WEAK WARM AIR
ADVECTION BACK INTO AREA IN ADVANCE OF THIS WAVE...TEMPERATURES WILL
REMAIN MILD WITH UPPER 70S TO LOWER 80S COMMON FOR HIGH TEMPERATURES
DURING THE AFTERNOON. A SLIGHTLY DOWNSLOPING FLOW INTO METRO DETROIT
WILL MOST LIKELY GARNER A TEMPERATURE AROUND 83F.

SHOWER ACTIVITY WILL WANE QUICKLY IN THE EARLY EVENING AS LIFT FROM
THE SHORTWAVE SHIFTS EAST AND DAYTIME INSTABILITY IS LOST. WITH THE
COOLER AIRMASS SETTLING INTO THE AREA...EXPECT COOL READINGS TUESDAY
NIGHT WITH LOW TEMPERATURES DOWN INTO THE 50S IN MOST LOCATIONS AND
PROBABLY RIGHT AROUND 50F IN SOME LOCATIONS ALONG THE NORTH OF ABOUT
THE I-69 CORRIDOR. THESE COOL TEMPERATURES WILL PERSIST INTO THE
MIDDLE OF THE WEEK AS CANADIAN HIGH PRESSURE BUILDS INTO AREA WITHIN
NORTHWEST FLOW REGIME. HIGHS WEDNESDAY WILL HOLD IN THE LOWER/MID
70S WITH LOWS BACK INTO THE 50S WEDNESDAY NIGHT. WITH THIS HIGH IN
PLACE...DRY WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT.

THURSDAY THROUGH MONDAY.

MODELS APPEAR TO BE IN HIGH DISAGREEMENT WITH THURSDAY`S WEATHER
SCENARIO...WHICH LENDS LOW CONFIDENCE TO PRETTY MUCH ALL OF THE
EXTENDED PERIOD. WEDNESDAY IS STILL FAVORING HIGH PRESSURE AND DRY
CONDITIONS...SO WILL CONTINUE TO FOLLOW YESTERDAY`S THINKING AND
HOLD OVER DRY CONDITIONS FOR MOST OF SOUTHEAST MICHIGAN ON THURSDAY
MORNING. THE EXCEPTION WILL REMAIN THE SOUTHERN MOST COUNTIES WHERE
SCATTERED SHOWERS WILL BEGIN EDGING INTO THE CWA PRIOR TO 8AM. WILL
ALSO KEEP SHOWERS EXPANDING INTO THE CWA THROUGH THE AFTERNOON AND
EVENING. AT LEAST A SLIGHT CHANCE OF SHOWERS IS FAVORED THROUGH THE
WEEKEND. MID 70 DEGREE HIGHS ANTICIPATED THROUGH SATURDAY WITH HIGH
TEMPS NUDGING INTO THE UPPER 70S BY SUNDAY.

MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THESE SYSTEMS WILL ALSO BRING SCATTERED SHOWERS
AND A FEW THUNDERSTORMS TO MAINLY LAKE HURON TODAY AND AGAIN TUESDAY
AFTERNOON AND EVENING.

THE FIRST SUCH FRONT WILL BRING GUSTS OVER PARTS OF THE LAKE HURON
OPEN WATERS TO 20 KNOTS OR A BIT MORE THIS EVENING...WITH A SECOND
FRONT BRINGING SLIGHTLY STRONGER WINDS OVERNIGHT TUESDAY NIGHT WITH
GUSTS IN THE 25 KNOT AREA. WHILE THIS SYSTEM MAY BRING CONDITIONS
APPROACHING SMALL CRAFT ADVISORIES...THE NORTHWEST TRAJECTORY WILL

WINDS WILL THEN SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE
SYSTEM APPROACHES WITH A LIGHT AND VARIABLE WIND FIELD ON THURSDAY
AS THIS HIGH BUILDS OVER THE REGION.

&&

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

$$

AVIATION.....HLO
SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG


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





000
FXUS63 KDTX 032349
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
749 PM EDT MON AUG 3 2015


.AVIATION...

SKIES WILL CLEAR FROM PTK SOUTH AS WE LOSE DAYTIME HEATING. FURTHER
NORTH...THE APPROACH OF ANOTHER UPPER LEVEL DISTURBANCE WILL KEEP
CLOUDS AROUND THROUGH THE NIGHTTIME HOURS. A WEAK FRONTAL BOUNDARY
WILL DROP THROUGH THE AREA TUESDAY...TRIGGERING SHOWERS AND A FEW
THUNDERSTORMS AS DAYTIME HEATING INCREASES INSTABILITY. BEST
POTENTIAL TO SEE A SHOWER/TSTORM WILL BE AT MBS...HOWEVER COVERAGE
LOOKS LOW ENOUGH AT THIS TIME TO PRECLUDE A MENTION IN THE TAFS.

FOR DTW...SHOWERS AND THUNDERSTORM ACTIVITY HAS ENDED FOR SOUTHERN
LOWER MICHIGAN...AND EXPECTING A QUIET NIGHT. SKIES WILL BE MOSTLY
CLEAR AS DAYTIME HEATING ALLOWS DAYTIME CU TO DISSIPATE. A WEAK
FRONTAL BOUNDARY DROPPING THROUGH THE AREA WILL ALLOW CLOUD COVER TO
INCREASE ONCE AGAIN ON TUESDAY...WITH SKIES BECOMING BKN NEAR 5000
FEET BY ABOUT 16Z. SHOWERS AND THUNDERSTORMS THAT DEVELOP TOMORROW
ARE EXPECTED TO REMAIN NORTH OF DTW.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

.PREV DISCUSSION...ISSUED 344 PM EDT MON AUG 3 2015

SHORT TERM...THIS EVENING THROUGH TONIGHT

A SECONDARY COLD FRONTAL TROUGH SWINGING THROUGH LOWER MI TODAY
PRODUCED ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND
THUNDERSTORMS...WHICH WILL WANE INTO THE EVENING HOURS. THE PRE-
FRONTAL AIRMASS WAS ABLE TO REACH INTO THE UPPER 70S/LOW 80S WITH
LOW 60 DEWPOINTS...COMBINED WITH FAVORABLE LOW/MID LEVEL LAPSE RATES
AIDED BY CAA ALOFT AND THE FRONTAL FORCING WAS ABLE TO PRODUCE SOME
WEAK THUNDERSTORMS. THE SFC FRONT IS NOW EXTENDING ALONG A LINE FROM
BAX TO JACKSON AND WILL CONTINUE EASTWARD...EXITING SE MI THIS
EVENING...LEAVING A DRIER FORECAST IN ITS WAKE. CLOUD TRENDS THIS
EVENING AND OVERNIGHT ARE LOOKING A BIT TRICKIER. MUCH DRIER
DEWPOINTS IN THE LOW 50S...EVEN A FEW 40S NOTED IN MID MI...BEHIND
THE FRONT WILL TRY TO DRY THE COLUMN OUT QUICKLY...BUT VISIBLE
SATELLITE SHOWS A ROBUST CLOUD FIELD WITHIN THE DEEP CYCLONIC FLOW
WHICH WILL DROP SOUTH AND EAST AND SHOULD IMPACT LOCATIONS NORTH OF
I69 THROUGH MOST OF THE NIGHT. SO WE WILL LIKELY HAVE A GRADIENT OF
CLEAR TO MOSTLY CLOUDS SET UP ACROSS OUT CWA AND HAVE HEDGED THE
FORECAST ACCORDINGLY.

LONG TERM...

ANOTHER VIGOROUS SPOKE OF SHORTWAVE ENERGY IS DUE INTO THE AREA ON
TUESDAY AS STRONG UPPER LOW PRESSURE REMAINS CENTERED NEAR JAMES BAY
FOR ANOTHER DAY. MUCH LIKE TODAY...EXPECT AN EXPANDING AREA OF
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS AS ENHANCED LIFT
FROM THIS WAVE COINCIDES WITH DAYTIME INSTABILITY MAXIMUM. WITH THE
OVERALL UPPER TROUGH AXIS SLOWLY EDGING EASTWARD DURING THIS TIME
FRAME...EXPECT THE BEST CONCENTRATION OF THIS CONVECTION TO OCCUR
OVER LAKE HURON/THUMB REGION WITH A STEADILY DIMINISHING CHANCE OF
RAINFALL SOUTHWEST FROM THERE. WITH NEUTRAL TO WEAK WARM AIR
ADVECTION BACK INTO AREA IN ADVANCE OF THIS WAVE...TEMPERATURES WILL
REMAIN MILD WITH UPPER 70S TO LOWER 80S COMMON FOR HIGH TEMPERATURES
DURING THE AFTERNOON. A SLIGHTLY DOWNSLOPING FLOW INTO METRO DETROIT
WILL MOST LIKELY GARNER A TEMPERATURE AROUND 83F.

SHOWER ACTIVITY WILL WANE QUICKLY IN THE EARLY EVENING AS LIFT FROM
THE SHORTWAVE SHIFTS EAST AND DAYTIME INSTABILITY IS LOST. WITH THE
COOLER AIRMASS SETTLING INTO THE AREA...EXPECT COOL READINGS TUESDAY
NIGHT WITH LOW TEMPERATURES DOWN INTO THE 50S IN MOST LOCATIONS AND
PROBABLY RIGHT AROUND 50F IN SOME LOCATIONS ALONG THE NORTH OF ABOUT
THE I-69 CORRIDOR. THESE COOL TEMPERATURES WILL PERSIST INTO THE
MIDDLE OF THE WEEK AS CANADIAN HIGH PRESSURE BUILDS INTO AREA WITHIN
NORTHWEST FLOW REGIME. HIGHS WEDNESDAY WILL HOLD IN THE LOWER/MID
70S WITH LOWS BACK INTO THE 50S WEDNESDAY NIGHT. WITH THIS HIGH IN
PLACE...DRY WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT.

THURSDAY THROUGH MONDAY.

MODELS APPEAR TO BE IN HIGH DISAGREEMENT WITH THURSDAY`S WEATHER
SCENARIO...WHICH LENDS LOW CONFIDENCE TO PRETTY MUCH ALL OF THE
EXTENDED PERIOD. WEDNESDAY IS STILL FAVORING HIGH PRESSURE AND DRY
CONDITIONS...SO WILL CONTINUE TO FOLLOW YESTERDAY`S THINKING AND
HOLD OVER DRY CONDITIONS FOR MOST OF SOUTHEAST MICHIGAN ON THURSDAY
MORNING. THE EXCEPTION WILL REMAIN THE SOUTHERN MOST COUNTIES WHERE
SCATTERED SHOWERS WILL BEGIN EDGING INTO THE CWA PRIOR TO 8AM. WILL
ALSO KEEP SHOWERS EXPANDING INTO THE CWA THROUGH THE AFTERNOON AND
EVENING. AT LEAST A SLIGHT CHANCE OF SHOWERS IS FAVORED THROUGH THE
WEEKEND. MID 70 DEGREE HIGHS ANTICIPATED THROUGH SATURDAY WITH HIGH
TEMPS NUDGING INTO THE UPPER 70S BY SUNDAY.

MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THESE SYSTEMS WILL ALSO BRING SCATTERED SHOWERS
AND A FEW THUNDERSTORMS TO MAINLY LAKE HURON TODAY AND AGAIN TUESDAY
AFTERNOON AND EVENING.

THE FIRST SUCH FRONT WILL BRING GUSTS OVER PARTS OF THE LAKE HURON
OPEN WATERS TO 20 KNOTS OR A BIT MORE THIS EVENING...WITH A SECOND
FRONT BRINGING SLIGHTLY STRONGER WINDS OVERNIGHT TUESDAY NIGHT WITH
GUSTS IN THE 25 KNOT AREA. WHILE THIS SYSTEM MAY BRING CONDITIONS
APPROACHING SMALL CRAFT ADVISORIES...THE NORTHWEST TRAJECTORY WILL

WINDS WILL THEN SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE
SYSTEM APPROACHES WITH A LIGHT AND VARIABLE WIND FIELD ON THURSDAY
AS THIS HIGH BUILDS OVER THE REGION.

&&

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

$$

AVIATION.....HLO
SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG


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




000
FXUS63 KDTX 032349
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
749 PM EDT MON AUG 3 2015


.AVIATION...

SKIES WILL CLEAR FROM PTK SOUTH AS WE LOSE DAYTIME HEATING. FURTHER
NORTH...THE APPROACH OF ANOTHER UPPER LEVEL DISTURBANCE WILL KEEP
CLOUDS AROUND THROUGH THE NIGHTTIME HOURS. A WEAK FRONTAL BOUNDARY
WILL DROP THROUGH THE AREA TUESDAY...TRIGGERING SHOWERS AND A FEW
THUNDERSTORMS AS DAYTIME HEATING INCREASES INSTABILITY. BEST
POTENTIAL TO SEE A SHOWER/TSTORM WILL BE AT MBS...HOWEVER COVERAGE
LOOKS LOW ENOUGH AT THIS TIME TO PRECLUDE A MENTION IN THE TAFS.

FOR DTW...SHOWERS AND THUNDERSTORM ACTIVITY HAS ENDED FOR SOUTHERN
LOWER MICHIGAN...AND EXPECTING A QUIET NIGHT. SKIES WILL BE MOSTLY
CLEAR AS DAYTIME HEATING ALLOWS DAYTIME CU TO DISSIPATE. A WEAK
FRONTAL BOUNDARY DROPPING THROUGH THE AREA WILL ALLOW CLOUD COVER TO
INCREASE ONCE AGAIN ON TUESDAY...WITH SKIES BECOMING BKN NEAR 5000
FEET BY ABOUT 16Z. SHOWERS AND THUNDERSTORMS THAT DEVELOP TOMORROW
ARE EXPECTED TO REMAIN NORTH OF DTW.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

.PREV DISCUSSION...ISSUED 344 PM EDT MON AUG 3 2015

SHORT TERM...THIS EVENING THROUGH TONIGHT

A SECONDARY COLD FRONTAL TROUGH SWINGING THROUGH LOWER MI TODAY
PRODUCED ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND
THUNDERSTORMS...WHICH WILL WANE INTO THE EVENING HOURS. THE PRE-
FRONTAL AIRMASS WAS ABLE TO REACH INTO THE UPPER 70S/LOW 80S WITH
LOW 60 DEWPOINTS...COMBINED WITH FAVORABLE LOW/MID LEVEL LAPSE RATES
AIDED BY CAA ALOFT AND THE FRONTAL FORCING WAS ABLE TO PRODUCE SOME
WEAK THUNDERSTORMS. THE SFC FRONT IS NOW EXTENDING ALONG A LINE FROM
BAX TO JACKSON AND WILL CONTINUE EASTWARD...EXITING SE MI THIS
EVENING...LEAVING A DRIER FORECAST IN ITS WAKE. CLOUD TRENDS THIS
EVENING AND OVERNIGHT ARE LOOKING A BIT TRICKIER. MUCH DRIER
DEWPOINTS IN THE LOW 50S...EVEN A FEW 40S NOTED IN MID MI...BEHIND
THE FRONT WILL TRY TO DRY THE COLUMN OUT QUICKLY...BUT VISIBLE
SATELLITE SHOWS A ROBUST CLOUD FIELD WITHIN THE DEEP CYCLONIC FLOW
WHICH WILL DROP SOUTH AND EAST AND SHOULD IMPACT LOCATIONS NORTH OF
I69 THROUGH MOST OF THE NIGHT. SO WE WILL LIKELY HAVE A GRADIENT OF
CLEAR TO MOSTLY CLOUDS SET UP ACROSS OUT CWA AND HAVE HEDGED THE
FORECAST ACCORDINGLY.

LONG TERM...

ANOTHER VIGOROUS SPOKE OF SHORTWAVE ENERGY IS DUE INTO THE AREA ON
TUESDAY AS STRONG UPPER LOW PRESSURE REMAINS CENTERED NEAR JAMES BAY
FOR ANOTHER DAY. MUCH LIKE TODAY...EXPECT AN EXPANDING AREA OF
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS AS ENHANCED LIFT
FROM THIS WAVE COINCIDES WITH DAYTIME INSTABILITY MAXIMUM. WITH THE
OVERALL UPPER TROUGH AXIS SLOWLY EDGING EASTWARD DURING THIS TIME
FRAME...EXPECT THE BEST CONCENTRATION OF THIS CONVECTION TO OCCUR
OVER LAKE HURON/THUMB REGION WITH A STEADILY DIMINISHING CHANCE OF
RAINFALL SOUTHWEST FROM THERE. WITH NEUTRAL TO WEAK WARM AIR
ADVECTION BACK INTO AREA IN ADVANCE OF THIS WAVE...TEMPERATURES WILL
REMAIN MILD WITH UPPER 70S TO LOWER 80S COMMON FOR HIGH TEMPERATURES
DURING THE AFTERNOON. A SLIGHTLY DOWNSLOPING FLOW INTO METRO DETROIT
WILL MOST LIKELY GARNER A TEMPERATURE AROUND 83F.

SHOWER ACTIVITY WILL WANE QUICKLY IN THE EARLY EVENING AS LIFT FROM
THE SHORTWAVE SHIFTS EAST AND DAYTIME INSTABILITY IS LOST. WITH THE
COOLER AIRMASS SETTLING INTO THE AREA...EXPECT COOL READINGS TUESDAY
NIGHT WITH LOW TEMPERATURES DOWN INTO THE 50S IN MOST LOCATIONS AND
PROBABLY RIGHT AROUND 50F IN SOME LOCATIONS ALONG THE NORTH OF ABOUT
THE I-69 CORRIDOR. THESE COOL TEMPERATURES WILL PERSIST INTO THE
MIDDLE OF THE WEEK AS CANADIAN HIGH PRESSURE BUILDS INTO AREA WITHIN
NORTHWEST FLOW REGIME. HIGHS WEDNESDAY WILL HOLD IN THE LOWER/MID
70S WITH LOWS BACK INTO THE 50S WEDNESDAY NIGHT. WITH THIS HIGH IN
PLACE...DRY WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT.

THURSDAY THROUGH MONDAY.

MODELS APPEAR TO BE IN HIGH DISAGREEMENT WITH THURSDAY`S WEATHER
SCENARIO...WHICH LENDS LOW CONFIDENCE TO PRETTY MUCH ALL OF THE
EXTENDED PERIOD. WEDNESDAY IS STILL FAVORING HIGH PRESSURE AND DRY
CONDITIONS...SO WILL CONTINUE TO FOLLOW YESTERDAY`S THINKING AND
HOLD OVER DRY CONDITIONS FOR MOST OF SOUTHEAST MICHIGAN ON THURSDAY
MORNING. THE EXCEPTION WILL REMAIN THE SOUTHERN MOST COUNTIES WHERE
SCATTERED SHOWERS WILL BEGIN EDGING INTO THE CWA PRIOR TO 8AM. WILL
ALSO KEEP SHOWERS EXPANDING INTO THE CWA THROUGH THE AFTERNOON AND
EVENING. AT LEAST A SLIGHT CHANCE OF SHOWERS IS FAVORED THROUGH THE
WEEKEND. MID 70 DEGREE HIGHS ANTICIPATED THROUGH SATURDAY WITH HIGH
TEMPS NUDGING INTO THE UPPER 70S BY SUNDAY.

MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THESE SYSTEMS WILL ALSO BRING SCATTERED SHOWERS
AND A FEW THUNDERSTORMS TO MAINLY LAKE HURON TODAY AND AGAIN TUESDAY
AFTERNOON AND EVENING.

THE FIRST SUCH FRONT WILL BRING GUSTS OVER PARTS OF THE LAKE HURON
OPEN WATERS TO 20 KNOTS OR A BIT MORE THIS EVENING...WITH A SECOND
FRONT BRINGING SLIGHTLY STRONGER WINDS OVERNIGHT TUESDAY NIGHT WITH
GUSTS IN THE 25 KNOT AREA. WHILE THIS SYSTEM MAY BRING CONDITIONS
APPROACHING SMALL CRAFT ADVISORIES...THE NORTHWEST TRAJECTORY WILL

WINDS WILL THEN SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE
SYSTEM APPROACHES WITH A LIGHT AND VARIABLE WIND FIELD ON THURSDAY
AS THIS HIGH BUILDS OVER THE REGION.

&&

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

$$

AVIATION.....HLO
SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG


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




000
FXUS63 KDTX 032349
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
749 PM EDT MON AUG 3 2015


.AVIATION...

SKIES WILL CLEAR FROM PTK SOUTH AS WE LOSE DAYTIME HEATING. FURTHER
NORTH...THE APPROACH OF ANOTHER UPPER LEVEL DISTURBANCE WILL KEEP
CLOUDS AROUND THROUGH THE NIGHTTIME HOURS. A WEAK FRONTAL BOUNDARY
WILL DROP THROUGH THE AREA TUESDAY...TRIGGERING SHOWERS AND A FEW
THUNDERSTORMS AS DAYTIME HEATING INCREASES INSTABILITY. BEST
POTENTIAL TO SEE A SHOWER/TSTORM WILL BE AT MBS...HOWEVER COVERAGE
LOOKS LOW ENOUGH AT THIS TIME TO PRECLUDE A MENTION IN THE TAFS.

FOR DTW...SHOWERS AND THUNDERSTORM ACTIVITY HAS ENDED FOR SOUTHERN
LOWER MICHIGAN...AND EXPECTING A QUIET NIGHT. SKIES WILL BE MOSTLY
CLEAR AS DAYTIME HEATING ALLOWS DAYTIME CU TO DISSIPATE. A WEAK
FRONTAL BOUNDARY DROPPING THROUGH THE AREA WILL ALLOW CLOUD COVER TO
INCREASE ONCE AGAIN ON TUESDAY...WITH SKIES BECOMING BKN NEAR 5000
FEET BY ABOUT 16Z. SHOWERS AND THUNDERSTORMS THAT DEVELOP TOMORROW
ARE EXPECTED TO REMAIN NORTH OF DTW.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

.PREV DISCUSSION...ISSUED 344 PM EDT MON AUG 3 2015

SHORT TERM...THIS EVENING THROUGH TONIGHT

A SECONDARY COLD FRONTAL TROUGH SWINGING THROUGH LOWER MI TODAY
PRODUCED ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND
THUNDERSTORMS...WHICH WILL WANE INTO THE EVENING HOURS. THE PRE-
FRONTAL AIRMASS WAS ABLE TO REACH INTO THE UPPER 70S/LOW 80S WITH
LOW 60 DEWPOINTS...COMBINED WITH FAVORABLE LOW/MID LEVEL LAPSE RATES
AIDED BY CAA ALOFT AND THE FRONTAL FORCING WAS ABLE TO PRODUCE SOME
WEAK THUNDERSTORMS. THE SFC FRONT IS NOW EXTENDING ALONG A LINE FROM
BAX TO JACKSON AND WILL CONTINUE EASTWARD...EXITING SE MI THIS
EVENING...LEAVING A DRIER FORECAST IN ITS WAKE. CLOUD TRENDS THIS
EVENING AND OVERNIGHT ARE LOOKING A BIT TRICKIER. MUCH DRIER
DEWPOINTS IN THE LOW 50S...EVEN A FEW 40S NOTED IN MID MI...BEHIND
THE FRONT WILL TRY TO DRY THE COLUMN OUT QUICKLY...BUT VISIBLE
SATELLITE SHOWS A ROBUST CLOUD FIELD WITHIN THE DEEP CYCLONIC FLOW
WHICH WILL DROP SOUTH AND EAST AND SHOULD IMPACT LOCATIONS NORTH OF
I69 THROUGH MOST OF THE NIGHT. SO WE WILL LIKELY HAVE A GRADIENT OF
CLEAR TO MOSTLY CLOUDS SET UP ACROSS OUT CWA AND HAVE HEDGED THE
FORECAST ACCORDINGLY.

LONG TERM...

ANOTHER VIGOROUS SPOKE OF SHORTWAVE ENERGY IS DUE INTO THE AREA ON
TUESDAY AS STRONG UPPER LOW PRESSURE REMAINS CENTERED NEAR JAMES BAY
FOR ANOTHER DAY. MUCH LIKE TODAY...EXPECT AN EXPANDING AREA OF
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS AS ENHANCED LIFT
FROM THIS WAVE COINCIDES WITH DAYTIME INSTABILITY MAXIMUM. WITH THE
OVERALL UPPER TROUGH AXIS SLOWLY EDGING EASTWARD DURING THIS TIME
FRAME...EXPECT THE BEST CONCENTRATION OF THIS CONVECTION TO OCCUR
OVER LAKE HURON/THUMB REGION WITH A STEADILY DIMINISHING CHANCE OF
RAINFALL SOUTHWEST FROM THERE. WITH NEUTRAL TO WEAK WARM AIR
ADVECTION BACK INTO AREA IN ADVANCE OF THIS WAVE...TEMPERATURES WILL
REMAIN MILD WITH UPPER 70S TO LOWER 80S COMMON FOR HIGH TEMPERATURES
DURING THE AFTERNOON. A SLIGHTLY DOWNSLOPING FLOW INTO METRO DETROIT
WILL MOST LIKELY GARNER A TEMPERATURE AROUND 83F.

SHOWER ACTIVITY WILL WANE QUICKLY IN THE EARLY EVENING AS LIFT FROM
THE SHORTWAVE SHIFTS EAST AND DAYTIME INSTABILITY IS LOST. WITH THE
COOLER AIRMASS SETTLING INTO THE AREA...EXPECT COOL READINGS TUESDAY
NIGHT WITH LOW TEMPERATURES DOWN INTO THE 50S IN MOST LOCATIONS AND
PROBABLY RIGHT AROUND 50F IN SOME LOCATIONS ALONG THE NORTH OF ABOUT
THE I-69 CORRIDOR. THESE COOL TEMPERATURES WILL PERSIST INTO THE
MIDDLE OF THE WEEK AS CANADIAN HIGH PRESSURE BUILDS INTO AREA WITHIN
NORTHWEST FLOW REGIME. HIGHS WEDNESDAY WILL HOLD IN THE LOWER/MID
70S WITH LOWS BACK INTO THE 50S WEDNESDAY NIGHT. WITH THIS HIGH IN
PLACE...DRY WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT.

THURSDAY THROUGH MONDAY.

MODELS APPEAR TO BE IN HIGH DISAGREEMENT WITH THURSDAY`S WEATHER
SCENARIO...WHICH LENDS LOW CONFIDENCE TO PRETTY MUCH ALL OF THE
EXTENDED PERIOD. WEDNESDAY IS STILL FAVORING HIGH PRESSURE AND DRY
CONDITIONS...SO WILL CONTINUE TO FOLLOW YESTERDAY`S THINKING AND
HOLD OVER DRY CONDITIONS FOR MOST OF SOUTHEAST MICHIGAN ON THURSDAY
MORNING. THE EXCEPTION WILL REMAIN THE SOUTHERN MOST COUNTIES WHERE
SCATTERED SHOWERS WILL BEGIN EDGING INTO THE CWA PRIOR TO 8AM. WILL
ALSO KEEP SHOWERS EXPANDING INTO THE CWA THROUGH THE AFTERNOON AND
EVENING. AT LEAST A SLIGHT CHANCE OF SHOWERS IS FAVORED THROUGH THE
WEEKEND. MID 70 DEGREE HIGHS ANTICIPATED THROUGH SATURDAY WITH HIGH
TEMPS NUDGING INTO THE UPPER 70S BY SUNDAY.

MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THESE SYSTEMS WILL ALSO BRING SCATTERED SHOWERS
AND A FEW THUNDERSTORMS TO MAINLY LAKE HURON TODAY AND AGAIN TUESDAY
AFTERNOON AND EVENING.

THE FIRST SUCH FRONT WILL BRING GUSTS OVER PARTS OF THE LAKE HURON
OPEN WATERS TO 20 KNOTS OR A BIT MORE THIS EVENING...WITH A SECOND
FRONT BRINGING SLIGHTLY STRONGER WINDS OVERNIGHT TUESDAY NIGHT WITH
GUSTS IN THE 25 KNOT AREA. WHILE THIS SYSTEM MAY BRING CONDITIONS
APPROACHING SMALL CRAFT ADVISORIES...THE NORTHWEST TRAJECTORY WILL

WINDS WILL THEN SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE
SYSTEM APPROACHES WITH A LIGHT AND VARIABLE WIND FIELD ON THURSDAY
AS THIS HIGH BUILDS OVER THE REGION.

&&

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

$$

AVIATION.....HLO
SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG


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





000
FXUS63 KDTX 031944
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
344 PM EDT MON AUG 3 2015

.SHORT TERM...THIS EVENING THROUGH TONIGHT

A SECONDARY COLD FRONTAL TROUGH SWINGING THROUGH LOWER MI TODAY
PRODUCED ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND
THUNDERSTORMS...WHICH WILL WANE INTO THE EVENING HOURS. THE PRE-
FRONTAL AIRMASS WAS ABLE TO REACH INTO THE UPPER 70S/LOW 80S WITH
LOW 60 DEWPOINTS...COMBINED WITH FAVORABLE LOW/MID LEVEL LAPSE RATES
AIDED BY CAA ALOFT AND THE FRONTAL FORCING WAS ABLE TO PRODUCE SOME
WEAK THUNDERSTORMS. THE SFC FRONT IS NOW EXTENDING ALONG A LINE FROM
BAX TO JACKSON AND WILL CONTINUE EASTWARD...EXITING SE MI THIS
EVENING...LEAVING A DRIER FORECAST IN ITS WAKE. CLOUD TRENDS THIS
EVENING AND OVERNIGHT ARE LOOKING A BIT TRICKIER. MUCH DRIER
DEWPOINTS IN THE LOW 50S...EVEN A FEW 40S NOTED IN MID MI...BEHIND
THE FRONT WILL TRY TO DRY THE COLUMN OUT QUICKLY...BUT VISIBLE
SATELLITE SHOWS A ROBUST CLOUD FIELD WITHIN THE DEEP CYCLONIC FLOW
WHICH WILL DROP SOUTH AND EAST AND SHOULD IMPACT LOCATIONS NORTH OF
I69 THROUGH MOST OF THE NIGHT. SO WE WILL LIKELY HAVE A GRADIENT OF
CLEAR TO MOSTLY CLOUDS SET UP ACROSS OUT CWA AND HAVE HEDGED THE
FORECAST ACCORDINGLY.

&&

.LONG TERM...

ANOTHER VIGOROUS SPOKE OF SHORTWAVE ENERGY IS DUE INTO THE AREA ON
TUESDAY AS STRONG UPPER LOW PRESSURE REMAINS CENTERED NEAR JAMES BAY
FOR ANOTHER DAY. MUCH LIKE TODAY...EXPECT AN EXPANDING AREA OF
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS AS ENHANCED LIFT
FROM THIS WAVE COINCIDES WITH DAYTIME INSTABILITY MAXIMUM. WITH THE
OVERALL UPPER TROUGH AXIS SLOWLY EDGING EASTWARD DURING THIS TIME
FRAME...EXPECT THE BEST CONCENTRATION OF THIS CONVECTION TO OCCUR
OVER LAKE HURON/THUMB REGION WITH A STEADILY DIMINISHING CHANCE OF
RAINFALL SOUTHWEST FROM THERE. WITH NEUTRAL TO WEAK WARM AIR
ADVECTION BACK INTO AREA IN ADVANCE OF THIS WAVE...TEMPERATURES WILL
REMAIN MILD WITH UPPER 70S TO LOWER 80S COMMON FOR HIGH TEMPERATURES
DURING THE AFTERNOON. A SLIGHTLY DOWNSLOPING FLOW INTO METRO DETROIT
WILL MOST LIKELY GARNER A TEMPERATURE AROUND 83F.

SHOWER ACTIVITY WILL WANE QUICKLY IN THE EARLY EVENING AS LIFT FROM
THE SHORTWAVE SHIFTS EAST AND DAYTIME INSTABILITY IS LOST. WITH THE
COOLER AIRMASS SETTLING INTO THE AREA...EXPECT COOL READINGS TUESDAY
NIGHT WITH LOW TEMPERATURES DOWN INTO THE 50S IN MOST LOCATIONS AND
PROBABLY RIGHT AROUND 50F IN SOME LOCATIONS ALONG THE NORTH OF ABOUT
THE I-69 CORRIDOR. THESE COOL TEMPERATURES WILL PERSIST INTO THE
MIDDLE OF THE WEEK AS CANADIAN HIGH PRESSURE BUILDS INTO AREA WITHIN
NORTHWEST FLOW REGIME. HIGHS WEDNESDAY WILL HOLD IN THE LOWER/MID
70S WITH LOWS BACK INTO THE 50S WEDNESDAY NIGHT. WITH THIS HIGH IN
PLACE...DRY WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT.

THURSDAY THROUGH MONDAY.

MODELS APPEAR TO BE IN HIGH DISAGREEMENT WITH THURSDAY`S WEATHER
SCENARIO...WHICH LENDS LOW CONFIDENCE TO PRETTY MUCH ALL OF THE
EXTENDED PERIOD. WEDNESDAY IS STILL FAVORING HIGH PRESSURE AND DRY
CONDITIONS...SO WILL CONTINUE TO FOLLOW YESTERDAY`S THINKING AND
HOLD OVER DRY CONDITIONS FOR MOST OF SOUTHEAST MICHIGAN ON THURSDAY
MORNING. THE EXCEPTION WILL REMAIN THE SOUTHERN MOST COUNTIES WHERE
SCATTERED SHOWERS WILL BEGIN EDGING INTO THE CWA PRIOR TO 8AM. WILL
ALSO KEEP SHOWERS EXPANDING INTO THE CWA THROUGH THE AFTERNOON AND
EVENING. AT LEAST A SLIGHT CHANCE OF SHOWERS IS FAVORED THROUGH THE
WEEKEND. MID 70 DEGREE HIGHS ANTICIPATED THROUGH SATURDAY WITH HIGH
TEMPS NUDGING INTO THE UPPER 70S BY SUNDAY.

&&

.MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THESE SYSTEMS WILL ALSO BRING SCATTERED SHOWERS
AND A FEW THUNDERSTORMS TO MAINLY LAKE HURON TODAY AND AGAIN TUESDAY
AFTERNOON AND EVENING.

THE FIRST SUCH FRONT WILL BRING GUSTS OVER PARTS OF THE LAKE HURON
OPEN WATERS TO 20 KNOTS OR A BIT MORE THIS EVENING...WITH A SECOND
FRONT BRINGING SLIGHTLY STRONGER WINDS OVERNIGHT TUESDAY NIGHT WITH
GUSTS IN THE 25 KNOT AREA. WHILE THIS SYSTEM MAY BRING CONDITIONS
APPROACHING SMALL CRAFT ADVISORIES...THE NORTHWEST TRAJECTORY WILL

WINDS WILL THEN SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE
SYSTEM APPROACHES WITH A LIGHT AND VARIABLE WIND FIELD ON THURSDAY
AS THIS HIGH BUILDS OVER THE REGION.

&&

.AVIATION...ISSUED 142 PM EDT MON AUG 3 2015

PRIMARILY VFR CONDITIONS THROUGH THE FORECAST AS DRIER AIR STARTS
MOVING INTO THE STATE. THE CAVEAT IS THE FIRST FEW HOURS OF THE
FORECAST THIS AFTERNOON AS A SYSTEM SLIDES THROUGH NORTHERN MI WITH
A TROUGH EXTENDING DOWN INTO SE MI. A NARROW CORRIDOR OF ISOLATED
SHOWERS HAS DEVELOPED AND WILL TRACK EASTWARD THROUGH THE AFTERNOON.
COVERAGE IS ISOLATED TO SCATTERED SO JUST INCLUDED TEMPOS FOR FNT
AND PTK. SOUTHERN FLANK IS NOT HOLDING TOGETHER PER VISIBLE
SATELLITE SO ELECTED NOT TO INCLUDE IN THE DETROIT TAFS. WESTERLY
WINDS WILL TOP OUT NEAR 20 KNOTS DURING THE AFTERNOON.

FOR DTW...THERE IS A CHANCE THAT THE ISOLATED SHOWERS COULD IMPACT
THE TERMINAL BETWEEN 20-23Z THIS AFTERNOON BUT ELECTED TO HOLD OFF
ON ANY MENTION DUE TO THE ISOLATED COVERAGE AND DRIER AIR TO THE
WEST. CURRENT SHOWERS TRACKING TOWARD PTK SHOULD STAY NORTH OF THE
TERMINAL.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

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

$$

SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG
AVIATION.....DRK


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




000
FXUS63 KDTX 031944
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
344 PM EDT MON AUG 3 2015

.SHORT TERM...THIS EVENING THROUGH TONIGHT

A SECONDARY COLD FRONTAL TROUGH SWINGING THROUGH LOWER MI TODAY
PRODUCED ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND
THUNDERSTORMS...WHICH WILL WANE INTO THE EVENING HOURS. THE PRE-
FRONTAL AIRMASS WAS ABLE TO REACH INTO THE UPPER 70S/LOW 80S WITH
LOW 60 DEWPOINTS...COMBINED WITH FAVORABLE LOW/MID LEVEL LAPSE RATES
AIDED BY CAA ALOFT AND THE FRONTAL FORCING WAS ABLE TO PRODUCE SOME
WEAK THUNDERSTORMS. THE SFC FRONT IS NOW EXTENDING ALONG A LINE FROM
BAX TO JACKSON AND WILL CONTINUE EASTWARD...EXITING SE MI THIS
EVENING...LEAVING A DRIER FORECAST IN ITS WAKE. CLOUD TRENDS THIS
EVENING AND OVERNIGHT ARE LOOKING A BIT TRICKIER. MUCH DRIER
DEWPOINTS IN THE LOW 50S...EVEN A FEW 40S NOTED IN MID MI...BEHIND
THE FRONT WILL TRY TO DRY THE COLUMN OUT QUICKLY...BUT VISIBLE
SATELLITE SHOWS A ROBUST CLOUD FIELD WITHIN THE DEEP CYCLONIC FLOW
WHICH WILL DROP SOUTH AND EAST AND SHOULD IMPACT LOCATIONS NORTH OF
I69 THROUGH MOST OF THE NIGHT. SO WE WILL LIKELY HAVE A GRADIENT OF
CLEAR TO MOSTLY CLOUDS SET UP ACROSS OUT CWA AND HAVE HEDGED THE
FORECAST ACCORDINGLY.

&&

.LONG TERM...

ANOTHER VIGOROUS SPOKE OF SHORTWAVE ENERGY IS DUE INTO THE AREA ON
TUESDAY AS STRONG UPPER LOW PRESSURE REMAINS CENTERED NEAR JAMES BAY
FOR ANOTHER DAY. MUCH LIKE TODAY...EXPECT AN EXPANDING AREA OF
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS AS ENHANCED LIFT
FROM THIS WAVE COINCIDES WITH DAYTIME INSTABILITY MAXIMUM. WITH THE
OVERALL UPPER TROUGH AXIS SLOWLY EDGING EASTWARD DURING THIS TIME
FRAME...EXPECT THE BEST CONCENTRATION OF THIS CONVECTION TO OCCUR
OVER LAKE HURON/THUMB REGION WITH A STEADILY DIMINISHING CHANCE OF
RAINFALL SOUTHWEST FROM THERE. WITH NEUTRAL TO WEAK WARM AIR
ADVECTION BACK INTO AREA IN ADVANCE OF THIS WAVE...TEMPERATURES WILL
REMAIN MILD WITH UPPER 70S TO LOWER 80S COMMON FOR HIGH TEMPERATURES
DURING THE AFTERNOON. A SLIGHTLY DOWNSLOPING FLOW INTO METRO DETROIT
WILL MOST LIKELY GARNER A TEMPERATURE AROUND 83F.

SHOWER ACTIVITY WILL WANE QUICKLY IN THE EARLY EVENING AS LIFT FROM
THE SHORTWAVE SHIFTS EAST AND DAYTIME INSTABILITY IS LOST. WITH THE
COOLER AIRMASS SETTLING INTO THE AREA...EXPECT COOL READINGS TUESDAY
NIGHT WITH LOW TEMPERATURES DOWN INTO THE 50S IN MOST LOCATIONS AND
PROBABLY RIGHT AROUND 50F IN SOME LOCATIONS ALONG THE NORTH OF ABOUT
THE I-69 CORRIDOR. THESE COOL TEMPERATURES WILL PERSIST INTO THE
MIDDLE OF THE WEEK AS CANADIAN HIGH PRESSURE BUILDS INTO AREA WITHIN
NORTHWEST FLOW REGIME. HIGHS WEDNESDAY WILL HOLD IN THE LOWER/MID
70S WITH LOWS BACK INTO THE 50S WEDNESDAY NIGHT. WITH THIS HIGH IN
PLACE...DRY WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT.

THURSDAY THROUGH MONDAY.

MODELS APPEAR TO BE IN HIGH DISAGREEMENT WITH THURSDAY`S WEATHER
SCENARIO...WHICH LENDS LOW CONFIDENCE TO PRETTY MUCH ALL OF THE
EXTENDED PERIOD. WEDNESDAY IS STILL FAVORING HIGH PRESSURE AND DRY
CONDITIONS...SO WILL CONTINUE TO FOLLOW YESTERDAY`S THINKING AND
HOLD OVER DRY CONDITIONS FOR MOST OF SOUTHEAST MICHIGAN ON THURSDAY
MORNING. THE EXCEPTION WILL REMAIN THE SOUTHERN MOST COUNTIES WHERE
SCATTERED SHOWERS WILL BEGIN EDGING INTO THE CWA PRIOR TO 8AM. WILL
ALSO KEEP SHOWERS EXPANDING INTO THE CWA THROUGH THE AFTERNOON AND
EVENING. AT LEAST A SLIGHT CHANCE OF SHOWERS IS FAVORED THROUGH THE
WEEKEND. MID 70 DEGREE HIGHS ANTICIPATED THROUGH SATURDAY WITH HIGH
TEMPS NUDGING INTO THE UPPER 70S BY SUNDAY.

&&

.MARINE...

WHILE HEADLINES ARE NOT EXPECTED OVER THE NEXT FEW DAYS OVER LAKE
HURON...A RATHER STRONG UPPER LOW FOR THIS TIME OF YEAR WILL REMAIN
DISPLACED SOUTH OF HUDSON BAY ALLOWING SEVERAL SHOTS OF COOLER AIR
WITH ACCOMPANYING GUSTY NORTH TO NORTHWEST WINDS IN THE WAKE OF THE
PASSING COLD FRONTS. THESE SYSTEMS WILL ALSO BRING SCATTERED SHOWERS
AND A FEW THUNDERSTORMS TO MAINLY LAKE HURON TODAY AND AGAIN TUESDAY
AFTERNOON AND EVENING.

THE FIRST SUCH FRONT WILL BRING GUSTS OVER PARTS OF THE LAKE HURON
OPEN WATERS TO 20 KNOTS OR A BIT MORE THIS EVENING...WITH A SECOND
FRONT BRINGING SLIGHTLY STRONGER WINDS OVERNIGHT TUESDAY NIGHT WITH
GUSTS IN THE 25 KNOT AREA. WHILE THIS SYSTEM MAY BRING CONDITIONS
APPROACHING SMALL CRAFT ADVISORIES...THE NORTHWEST TRAJECTORY WILL

WINDS WILL THEN SLOWLY DECREASE ON WEDNESDAY AS A HIGH PRESSURE
SYSTEM APPROACHES WITH A LIGHT AND VARIABLE WIND FIELD ON THURSDAY
AS THIS HIGH BUILDS OVER THE REGION.

&&

.AVIATION...ISSUED 142 PM EDT MON AUG 3 2015

PRIMARILY VFR CONDITIONS THROUGH THE FORECAST AS DRIER AIR STARTS
MOVING INTO THE STATE. THE CAVEAT IS THE FIRST FEW HOURS OF THE
FORECAST THIS AFTERNOON AS A SYSTEM SLIDES THROUGH NORTHERN MI WITH
A TROUGH EXTENDING DOWN INTO SE MI. A NARROW CORRIDOR OF ISOLATED
SHOWERS HAS DEVELOPED AND WILL TRACK EASTWARD THROUGH THE AFTERNOON.
COVERAGE IS ISOLATED TO SCATTERED SO JUST INCLUDED TEMPOS FOR FNT
AND PTK. SOUTHERN FLANK IS NOT HOLDING TOGETHER PER VISIBLE
SATELLITE SO ELECTED NOT TO INCLUDE IN THE DETROIT TAFS. WESTERLY
WINDS WILL TOP OUT NEAR 20 KNOTS DURING THE AFTERNOON.

FOR DTW...THERE IS A CHANCE THAT THE ISOLATED SHOWERS COULD IMPACT
THE TERMINAL BETWEEN 20-23Z THIS AFTERNOON BUT ELECTED TO HOLD OFF
ON ANY MENTION DUE TO THE ISOLATED COVERAGE AND DRIER AIR TO THE
WEST. CURRENT SHOWERS TRACKING TOWARD PTK SHOULD STAY NORTH OF THE
TERMINAL.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

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

$$

SHORT TERM...DRK
LONG TERM....DG/DE
MARINE.......DG
AVIATION.....DRK


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





000
FXUS63 KDTX 031742
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
142 PM EDT MON AUG 3 2015


.AVIATION...

PRIMARILY VFR CONDITIONS THROUGH THE FORECAST AS DRIER AIR STARTS
MOVING INTO THE STATE. THE CAVEAT IS THE FIRST FEW HOURS OF THE
FORECAST THIS AFTERNOON AS A SYSTEM SLIDES THROUGH NORTHERN MI WITH
A TROUGH EXTENDING DOWN INTO SE MI. A NARROW CORRIDOR OF ISOLATED
SHOWERS HAS DEVELOPED AND WILL TRACK EASTWARD THROUGH THE AFTERNOON.
COVERAGE IS ISOLATED TO SCATTERED SO JUST INCLUDED TEMPOS FOR FNT
AND PTK. SOUTHERN FLANK IS NOT HOLDING TOGETHER PER VISIBLE
SATELLITE SO ELECTED NOT TO INCLUDE IN THE DETROIT TAFS. WESTERLY
WINDS WILL TOP OUT NEAR 20 KNOTS DURING THE AFTERNOON.

FOR DTW...THERE IS A CHANCE THAT THE ISOLATED SHOWERS COULD IMPACT
THE TERMINAL BETWEEN 20-23Z THIS AFTERNOON BUT ELECTED TO HOLD OFF
ON ANY MENTION DUE TO THE ISOLATED COVERAGE AND DRIER AIR TO THE
WEST. CURRENT SHOWERS TRACKING TOWARD PTK SHOULD STAY NORTH OF THE
TERMINAL.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

.PREV DISCUSSION...ISSUED 1001 AM EDT MON AUG 3 2015

UPDATE...
POST FRONTAL CAA WILL LEAD TO DEEP MIXING...STRONG LL LAPSE
RATES... AND A FEW HUNDRED J/KG OF SBCAPE THIS AFTERNOON AHEAD OF
AN APPROACHING MID LEVEL SHORTWAVE. THE SHORTWAVE CURRENTLY OVER
THE UPPER PENINSULA WILL REACH SE MI THIS AFTERNOON DURING PEAK
HEATING. THOUGH MOISTURE PARAMETERS ARE NOT TOO IMPRESSIVE...PWATS
JUST UNDER AN INCH...THE AFOREMENTIONED INSTABILITY SHOULD BE
ENOUGH TO SPARK A FEW SHOWERS/THUNDERSTORMS ACROSS THE AREA.
LATEST HIRES MODELS ALL CONCUR AND ADVERTISE SPOTTY COVERAGE
ACROSS SOUTHERN MI. MAIN UPDATE WAS TO ADD ISOLATED
SHOWERS/THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON AND INTO THIS
EVENING.

PREV DISCUSSION...ISSUED 406 AM EDT MON AUG 3 2015

SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

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

$$

AVIATION.....DRK
UPDATE.......DRK
SHORT TERM...CB
LONG TERM....SF
MARINE.......SF


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





000
FXUS63 KDTX 031742
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
142 PM EDT MON AUG 3 2015


.AVIATION...

PRIMARILY VFR CONDITIONS THROUGH THE FORECAST AS DRIER AIR STARTS
MOVING INTO THE STATE. THE CAVEAT IS THE FIRST FEW HOURS OF THE
FORECAST THIS AFTERNOON AS A SYSTEM SLIDES THROUGH NORTHERN MI WITH
A TROUGH EXTENDING DOWN INTO SE MI. A NARROW CORRIDOR OF ISOLATED
SHOWERS HAS DEVELOPED AND WILL TRACK EASTWARD THROUGH THE AFTERNOON.
COVERAGE IS ISOLATED TO SCATTERED SO JUST INCLUDED TEMPOS FOR FNT
AND PTK. SOUTHERN FLANK IS NOT HOLDING TOGETHER PER VISIBLE
SATELLITE SO ELECTED NOT TO INCLUDE IN THE DETROIT TAFS. WESTERLY
WINDS WILL TOP OUT NEAR 20 KNOTS DURING THE AFTERNOON.

FOR DTW...THERE IS A CHANCE THAT THE ISOLATED SHOWERS COULD IMPACT
THE TERMINAL BETWEEN 20-23Z THIS AFTERNOON BUT ELECTED TO HOLD OFF
ON ANY MENTION DUE TO THE ISOLATED COVERAGE AND DRIER AIR TO THE
WEST. CURRENT SHOWERS TRACKING TOWARD PTK SHOULD STAY NORTH OF THE
TERMINAL.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

.PREV DISCUSSION...ISSUED 1001 AM EDT MON AUG 3 2015

UPDATE...
POST FRONTAL CAA WILL LEAD TO DEEP MIXING...STRONG LL LAPSE
RATES... AND A FEW HUNDRED J/KG OF SBCAPE THIS AFTERNOON AHEAD OF
AN APPROACHING MID LEVEL SHORTWAVE. THE SHORTWAVE CURRENTLY OVER
THE UPPER PENINSULA WILL REACH SE MI THIS AFTERNOON DURING PEAK
HEATING. THOUGH MOISTURE PARAMETERS ARE NOT TOO IMPRESSIVE...PWATS
JUST UNDER AN INCH...THE AFOREMENTIONED INSTABILITY SHOULD BE
ENOUGH TO SPARK A FEW SHOWERS/THUNDERSTORMS ACROSS THE AREA.
LATEST HIRES MODELS ALL CONCUR AND ADVERTISE SPOTTY COVERAGE
ACROSS SOUTHERN MI. MAIN UPDATE WAS TO ADD ISOLATED
SHOWERS/THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON AND INTO THIS
EVENING.

PREV DISCUSSION...ISSUED 406 AM EDT MON AUG 3 2015

SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

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

$$

AVIATION.....DRK
UPDATE.......DRK
SHORT TERM...CB
LONG TERM....SF
MARINE.......SF


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




000
FXUS63 KDTX 031742
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
142 PM EDT MON AUG 3 2015


.AVIATION...

PRIMARILY VFR CONDITIONS THROUGH THE FORECAST AS DRIER AIR STARTS
MOVING INTO THE STATE. THE CAVEAT IS THE FIRST FEW HOURS OF THE
FORECAST THIS AFTERNOON AS A SYSTEM SLIDES THROUGH NORTHERN MI WITH
A TROUGH EXTENDING DOWN INTO SE MI. A NARROW CORRIDOR OF ISOLATED
SHOWERS HAS DEVELOPED AND WILL TRACK EASTWARD THROUGH THE AFTERNOON.
COVERAGE IS ISOLATED TO SCATTERED SO JUST INCLUDED TEMPOS FOR FNT
AND PTK. SOUTHERN FLANK IS NOT HOLDING TOGETHER PER VISIBLE
SATELLITE SO ELECTED NOT TO INCLUDE IN THE DETROIT TAFS. WESTERLY
WINDS WILL TOP OUT NEAR 20 KNOTS DURING THE AFTERNOON.

FOR DTW...THERE IS A CHANCE THAT THE ISOLATED SHOWERS COULD IMPACT
THE TERMINAL BETWEEN 20-23Z THIS AFTERNOON BUT ELECTED TO HOLD OFF
ON ANY MENTION DUE TO THE ISOLATED COVERAGE AND DRIER AIR TO THE
WEST. CURRENT SHOWERS TRACKING TOWARD PTK SHOULD STAY NORTH OF THE
TERMINAL.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CIGS BELOW 5000 FT AGL TUESDAY.

&&

.PREV DISCUSSION...ISSUED 1001 AM EDT MON AUG 3 2015

UPDATE...
POST FRONTAL CAA WILL LEAD TO DEEP MIXING...STRONG LL LAPSE
RATES... AND A FEW HUNDRED J/KG OF SBCAPE THIS AFTERNOON AHEAD OF
AN APPROACHING MID LEVEL SHORTWAVE. THE SHORTWAVE CURRENTLY OVER
THE UPPER PENINSULA WILL REACH SE MI THIS AFTERNOON DURING PEAK
HEATING. THOUGH MOISTURE PARAMETERS ARE NOT TOO IMPRESSIVE...PWATS
JUST UNDER AN INCH...THE AFOREMENTIONED INSTABILITY SHOULD BE
ENOUGH TO SPARK A FEW SHOWERS/THUNDERSTORMS ACROSS THE AREA.
LATEST HIRES MODELS ALL CONCUR AND ADVERTISE SPOTTY COVERAGE
ACROSS SOUTHERN MI. MAIN UPDATE WAS TO ADD ISOLATED
SHOWERS/THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON AND INTO THIS
EVENING.

PREV DISCUSSION...ISSUED 406 AM EDT MON AUG 3 2015

SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

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

$$

AVIATION.....DRK
UPDATE.......DRK
SHORT TERM...CB
LONG TERM....SF
MARINE.......SF


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





000
FXUS63 KDTX 031401
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1001 AM EDT MON AUG 3 2015

.UPDATE...
POST FRONTAL CAA WILL LEAD TO DEEP MIXING...STRONG LL LAPSE
RATES... AND A FEW HUNDRED J/KG OF SBCAPE THIS AFTERNOON AHEAD OF
AN APPROACHING MID LEVEL SHORTWAVE. THE SHORTWAVE CURRENTLY OVER
THE UPPER PENINSULA WILL REACH SE MI THIS AFTERNOON DURING PEAK
HEATING. THOUGH MOISTURE PARAMETERS ARE NOT TOO IMPRESSIVE...PWATS
JUST UNDER AN INCH...THE AFOREMENTIONED INSTABILITY SHOULD BE
ENOUGH TO SPARK A FEW SHOWERS/THUNDERSTORMS ACROSS THE AREA.
LATEST HIRES MODELS ALL CONCUR AND ADVERTISE SPOTTY COVERAGE
ACROSS SOUTHERN MI. MAIN UPDATE WAS TO ADD ISOLATED
SHOWERS/THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON AND INTO THIS
EVENING.

&&

.AVIATION...ISSUED 558 AM EDT MON AUG 3 2015

THE ONSET OF LOW LEVEL COLD AIR ADVECTION ACTING UPON RESIDUAL
MOISTURE HAS LED TO THE DEVELOPMENT OF IFR/MVFR STRATUS OVER MUCH OF
SOUTHEASTERN MICHIGAN. TRANSIENT NATURE IN THE COVERAGE AND SHALLOW
DEPTH FORECASTED IN MODEL DATA SUPPORTS A RAPID LIFTING TREND WITH
GROWTH OF BOUNDARY LAYER. CLOUDS ARE THEN FORECASTED TO LIFT TODAY
BEFORE MIXING OUT BY THIS EVENING. TIGHT GRADIENT WITHIN CYCLONIC
FLOW WILL SUPPORT WEST WINDS RANGING BETWEEN 10 AND 20 KNOTS.

//DTW THRESHOLD PROBABILITIES...

* HIGH FOR CIGS BELOW 5000 FT AGL THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 406 AM EDT MON AUG 3 2015

SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
.AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

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

$$

UPDATE.......DRK
AVIATION.....CB
SHORT TERM...CB
LONG TERM....SF
MARINE.......SF


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




000
FXUS63 KDTX 031401
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1001 AM EDT MON AUG 3 2015

.UPDATE...
POST FRONTAL CAA WILL LEAD TO DEEP MIXING...STRONG LL LAPSE
RATES... AND A FEW HUNDRED J/KG OF SBCAPE THIS AFTERNOON AHEAD OF
AN APPROACHING MID LEVEL SHORTWAVE. THE SHORTWAVE CURRENTLY OVER
THE UPPER PENINSULA WILL REACH SE MI THIS AFTERNOON DURING PEAK
HEATING. THOUGH MOISTURE PARAMETERS ARE NOT TOO IMPRESSIVE...PWATS
JUST UNDER AN INCH...THE AFOREMENTIONED INSTABILITY SHOULD BE
ENOUGH TO SPARK A FEW SHOWERS/THUNDERSTORMS ACROSS THE AREA.
LATEST HIRES MODELS ALL CONCUR AND ADVERTISE SPOTTY COVERAGE
ACROSS SOUTHERN MI. MAIN UPDATE WAS TO ADD ISOLATED
SHOWERS/THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON AND INTO THIS
EVENING.

&&

.AVIATION...ISSUED 558 AM EDT MON AUG 3 2015

THE ONSET OF LOW LEVEL COLD AIR ADVECTION ACTING UPON RESIDUAL
MOISTURE HAS LED TO THE DEVELOPMENT OF IFR/MVFR STRATUS OVER MUCH OF
SOUTHEASTERN MICHIGAN. TRANSIENT NATURE IN THE COVERAGE AND SHALLOW
DEPTH FORECASTED IN MODEL DATA SUPPORTS A RAPID LIFTING TREND WITH
GROWTH OF BOUNDARY LAYER. CLOUDS ARE THEN FORECASTED TO LIFT TODAY
BEFORE MIXING OUT BY THIS EVENING. TIGHT GRADIENT WITHIN CYCLONIC
FLOW WILL SUPPORT WEST WINDS RANGING BETWEEN 10 AND 20 KNOTS.

//DTW THRESHOLD PROBABILITIES...

* HIGH FOR CIGS BELOW 5000 FT AGL THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 406 AM EDT MON AUG 3 2015

SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
.AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

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

$$

UPDATE.......DRK
AVIATION.....CB
SHORT TERM...CB
LONG TERM....SF
MARINE.......SF


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




000
FXUS63 KDTX 031401
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1001 AM EDT MON AUG 3 2015

.UPDATE...
POST FRONTAL CAA WILL LEAD TO DEEP MIXING...STRONG LL LAPSE
RATES... AND A FEW HUNDRED J/KG OF SBCAPE THIS AFTERNOON AHEAD OF
AN APPROACHING MID LEVEL SHORTWAVE. THE SHORTWAVE CURRENTLY OVER
THE UPPER PENINSULA WILL REACH SE MI THIS AFTERNOON DURING PEAK
HEATING. THOUGH MOISTURE PARAMETERS ARE NOT TOO IMPRESSIVE...PWATS
JUST UNDER AN INCH...THE AFOREMENTIONED INSTABILITY SHOULD BE
ENOUGH TO SPARK A FEW SHOWERS/THUNDERSTORMS ACROSS THE AREA.
LATEST HIRES MODELS ALL CONCUR AND ADVERTISE SPOTTY COVERAGE
ACROSS SOUTHERN MI. MAIN UPDATE WAS TO ADD ISOLATED
SHOWERS/THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON AND INTO THIS
EVENING.

&&

.AVIATION...ISSUED 558 AM EDT MON AUG 3 2015

THE ONSET OF LOW LEVEL COLD AIR ADVECTION ACTING UPON RESIDUAL
MOISTURE HAS LED TO THE DEVELOPMENT OF IFR/MVFR STRATUS OVER MUCH OF
SOUTHEASTERN MICHIGAN. TRANSIENT NATURE IN THE COVERAGE AND SHALLOW
DEPTH FORECASTED IN MODEL DATA SUPPORTS A RAPID LIFTING TREND WITH
GROWTH OF BOUNDARY LAYER. CLOUDS ARE THEN FORECASTED TO LIFT TODAY
BEFORE MIXING OUT BY THIS EVENING. TIGHT GRADIENT WITHIN CYCLONIC
FLOW WILL SUPPORT WEST WINDS RANGING BETWEEN 10 AND 20 KNOTS.

//DTW THRESHOLD PROBABILITIES...

* HIGH FOR CIGS BELOW 5000 FT AGL THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 406 AM EDT MON AUG 3 2015

SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
.AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

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

$$

UPDATE.......DRK
AVIATION.....CB
SHORT TERM...CB
LONG TERM....SF
MARINE.......SF


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





000
FXUS63 KDTX 031401
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1001 AM EDT MON AUG 3 2015

.UPDATE...
POST FRONTAL CAA WILL LEAD TO DEEP MIXING...STRONG LL LAPSE
RATES... AND A FEW HUNDRED J/KG OF SBCAPE THIS AFTERNOON AHEAD OF
AN APPROACHING MID LEVEL SHORTWAVE. THE SHORTWAVE CURRENTLY OVER
THE UPPER PENINSULA WILL REACH SE MI THIS AFTERNOON DURING PEAK
HEATING. THOUGH MOISTURE PARAMETERS ARE NOT TOO IMPRESSIVE...PWATS
JUST UNDER AN INCH...THE AFOREMENTIONED INSTABILITY SHOULD BE
ENOUGH TO SPARK A FEW SHOWERS/THUNDERSTORMS ACROSS THE AREA.
LATEST HIRES MODELS ALL CONCUR AND ADVERTISE SPOTTY COVERAGE
ACROSS SOUTHERN MI. MAIN UPDATE WAS TO ADD ISOLATED
SHOWERS/THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON AND INTO THIS
EVENING.

&&

.AVIATION...ISSUED 558 AM EDT MON AUG 3 2015

THE ONSET OF LOW LEVEL COLD AIR ADVECTION ACTING UPON RESIDUAL
MOISTURE HAS LED TO THE DEVELOPMENT OF IFR/MVFR STRATUS OVER MUCH OF
SOUTHEASTERN MICHIGAN. TRANSIENT NATURE IN THE COVERAGE AND SHALLOW
DEPTH FORECASTED IN MODEL DATA SUPPORTS A RAPID LIFTING TREND WITH
GROWTH OF BOUNDARY LAYER. CLOUDS ARE THEN FORECASTED TO LIFT TODAY
BEFORE MIXING OUT BY THIS EVENING. TIGHT GRADIENT WITHIN CYCLONIC
FLOW WILL SUPPORT WEST WINDS RANGING BETWEEN 10 AND 20 KNOTS.

//DTW THRESHOLD PROBABILITIES...

* HIGH FOR CIGS BELOW 5000 FT AGL THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 406 AM EDT MON AUG 3 2015

SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
.AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

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

$$

UPDATE.......DRK
AVIATION.....CB
SHORT TERM...CB
LONG TERM....SF
MARINE.......SF


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





000
FXUS63 KDTX 030958
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
558 AM EDT MON AUG 3 2015


.AVIATION...

THE ONSET OF LOW LEVEL COLD AIR ADVECTION ACTING UPON RESIDUAL
MOISTURE HAS LED TO THE DEVELOPMENT OF IFR/MVFR STRATUS OVER MUCH OF
SOUTHEASTERN MICHIGAN. TRANSIENT NATURE IN THE COVERAGE AND SHALLOW
DEPTH FORECASTED IN MODEL DATA SUPPORTS A RAPID LIFTING TREND WITH
GROWTH OF BOUNDARY LAYER. CLOUDS ARE THEN FORECASTED TO LIFT TODAY
BEFORE MIXING OUT BY THIS EVENING. TIGHT GRADIENT WITHIN CYCLONIC
FLOW WILL SUPPORT WEST WINDS RANGING BETWEEN 10 AND 20 KNOTS.


//DTW THRESHOLD PROBABILITIES...

* HIGH FOR CIGS BELOW 5000 FT AGL THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 406 AM EDT MON AUG 3 2015

SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
..AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

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

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....SF
MARINE.......SF


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





000
FXUS63 KDTX 030958
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
558 AM EDT MON AUG 3 2015


.AVIATION...

THE ONSET OF LOW LEVEL COLD AIR ADVECTION ACTING UPON RESIDUAL
MOISTURE HAS LED TO THE DEVELOPMENT OF IFR/MVFR STRATUS OVER MUCH OF
SOUTHEASTERN MICHIGAN. TRANSIENT NATURE IN THE COVERAGE AND SHALLOW
DEPTH FORECASTED IN MODEL DATA SUPPORTS A RAPID LIFTING TREND WITH
GROWTH OF BOUNDARY LAYER. CLOUDS ARE THEN FORECASTED TO LIFT TODAY
BEFORE MIXING OUT BY THIS EVENING. TIGHT GRADIENT WITHIN CYCLONIC
FLOW WILL SUPPORT WEST WINDS RANGING BETWEEN 10 AND 20 KNOTS.


//DTW THRESHOLD PROBABILITIES...

* HIGH FOR CIGS BELOW 5000 FT AGL THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 406 AM EDT MON AUG 3 2015

SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
..AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

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

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....SF
MARINE.......SF


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




000
FXUS63 KDTX 030806
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
406 AM EDT MON AUG 3 2015

.SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

&&

.LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
...AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

&&

.MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

.AVIATION...ISSUED 125 AM EDT MON AUG 3 2015

LINE OF THUNDERSTORMS HAS SETTLED INTO PORTIONS OF OHIO AND INDIANA.
TRAILING STRATIFORM PRECIPITATION WITH EMBEDDED LIGHTNING WILL
IMPACT THE SOUTHERN TERMINALS INTERMITTENTLY DURING THE FIRST
HOUR OR TWO OF THE TAF CYCLE. RESIDUAL MOISTURE WITH ONSET OF LOW
LEVEL COLD AIR ADVECTION SHOULD ALLOW IFR STRATUS DECK TO FILL IN
ACROSS THE NORTHERN HALF OF THE AREA. OBSERVING PLATFORMS HAVE
RECORDED THE IFR CIGS NOW ITS A QUESTION OF OVERALL DEVELOPING
COVERAGE. KEPT CIGS AT BORDERLINE IFR/MVFR FOR THE DETROIT
TERMINALS. DEVELOPING BOUNDARY LAYER TODAY WILL LEAD TO WEST WINDS
OF 10 TO 20 KNOTS. LOSS OF DAYTIME HEATING AND DRY AIR ADVECTION
IS EXPECTED TO LEAD TO PREDOMINATELY SKC CONDITIONS TONIGHT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN ISOLATED CLOUD TO GROUND LIGHTNING STRIKES BETWEEN 06-
  08Z.

* HIGH FOR CIGS BELOW 5000 FT AGL. LOW CONFIDENCE IN POTENTIAL FOR
  CIGS OF LESS THAN 1000 FT.

&&

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

$$

SHORT TERM...CB
LONG TERM....SF
MARINE.......SF
AVIATION.....CB


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





000
FXUS63 KDTX 030806
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
406 AM EDT MON AUG 3 2015

.SHORT TERM...TODAY AND TONIGHT

DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS
MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH
OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY
SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR
TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR
ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC
DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER
PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE
NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP
LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND
FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE
GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY
LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN
THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY
MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT
ISLAND SOUTH AND EAST OF THE TERRAIN.

&&

.LONG TERM...

VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN
CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING
AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN
HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE
NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB
TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH
DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S
LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD
SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG
...AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT
SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED
MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS
RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO
BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES.

CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE
BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME
MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS
TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE
COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500
MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS
POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER
OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS
MID LEVEL CIRCULATION.

&&

.MARINE...

COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND
LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE
DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A
SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE
WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE
HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE
IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE
WIND FIELD.

&&

.AVIATION...ISSUED 125 AM EDT MON AUG 3 2015

LINE OF THUNDERSTORMS HAS SETTLED INTO PORTIONS OF OHIO AND INDIANA.
TRAILING STRATIFORM PRECIPITATION WITH EMBEDDED LIGHTNING WILL
IMPACT THE SOUTHERN TERMINALS INTERMITTENTLY DURING THE FIRST
HOUR OR TWO OF THE TAF CYCLE. RESIDUAL MOISTURE WITH ONSET OF LOW
LEVEL COLD AIR ADVECTION SHOULD ALLOW IFR STRATUS DECK TO FILL IN
ACROSS THE NORTHERN HALF OF THE AREA. OBSERVING PLATFORMS HAVE
RECORDED THE IFR CIGS NOW ITS A QUESTION OF OVERALL DEVELOPING
COVERAGE. KEPT CIGS AT BORDERLINE IFR/MVFR FOR THE DETROIT
TERMINALS. DEVELOPING BOUNDARY LAYER TODAY WILL LEAD TO WEST WINDS
OF 10 TO 20 KNOTS. LOSS OF DAYTIME HEATING AND DRY AIR ADVECTION
IS EXPECTED TO LEAD TO PREDOMINATELY SKC CONDITIONS TONIGHT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN ISOLATED CLOUD TO GROUND LIGHTNING STRIKES BETWEEN 06-
  08Z.

* HIGH FOR CIGS BELOW 5000 FT AGL. LOW CONFIDENCE IN POTENTIAL FOR
  CIGS OF LESS THAN 1000 FT.

&&

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

$$

SHORT TERM...CB
LONG TERM....SF
MARINE.......SF
AVIATION.....CB


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




000
FXUS63 KDTX 030525
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
125 AM EDT MON AUG 3 2015


.AVIATION...

LINE OF THUNDERSTORMS HAS SETTLED INTO PORTIONS OF OHIO AND INDIANA.
TRAILING STRATIFORM PRECIPITATION WITH EMBEDDED LIGHTNING WILL
IMPACT THE SOUTHERN TERMINALS OMITTENLY DURING THE FIRST HOUR OR TWO
OF THE TAF CYCLE. RESIDUAL MOISTURE WITH ONSET OF LOW LEVEL COLD AIR
ADVECTION SHOULD ALLOW IFR STRATUS DECK TO FILL IN ACROSS THE
NORTHERN HALF OF THE AREA. OBSERVING PLATFORMS HAVE RECORDED THE IFR
CIGS NOW ITS A QUESTION OF OVERALL DEVELOPING COVERAGE. KEPT CIGS AT
BORDERLINE IFR/MVFR FOR THE DETROIT TERMINALS. DEVELOPING BOUNDARY
LAYER TODAY WILL LEAD TO WEST WINDS OF 10 TO 20 KNOTS. LOSS OF
DAYTIME HEATING AND DRY AIR ADVECTION IS EXPECTED TO LEAD TO
PREDOMINATELY SKC CONDITIONS TONIGHT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN ISOLATED CLOUD TO GROUND LIGHTNING STRIKES BETWEEN 06-
  08Z.

* HIGH FOR CIGS BELOW 5000 FT AGL. LOW CONFIDENCE IN POTENTIAL FOR
  CIGS OF LESS THAN 1000 FT.

&&

.PREV DISCUSSION...ISSUED 325 PM EDT SUN AUG 2 2015

SHORT TERM...THIS AFTERNOON AND TONIGHT

SCATTERED CONVECTION CONTINUES TO BUBBLE OVER FAR NORTHERN CWA ALONG
WEST TO EAST OUTFLOW BOUNDARY STALLED OVER THAT AREA ALONG SOUTHERN
PERIPHERY OF CONVECTIVE CLUSTER TRACK(S) FROM THIS MORNING AND EARLY
AFTERNOON. EXPECT THIS ACTIVITY TO GRADUALLY INCREASE IN COVERAGE
THROUGH THE REST OF THE AFTERNOON...AT LEAST NORTH OF THE INTERSTATE
69 CORRIDOR. GIVEN THE DEGREE OF INSTABILITY ADVECTING INTO AREA FROM
THE WEST AND SOUTHWEST AND FEEDING THIS ACTIVITY...EXPECT SOME OF
THESE STORMS TO BE SEVERE. TO THIS POINT...THIS ACTIVITY HAS HAS
REMAIN CONFINED TO THE SAGINAW VALLEY AND NORTHERN THUMB. IF THIS
REMAINS THE CASE...LATER ACTIVITY THIS EVENING SHOULD HAVE A
STRAIGHT SHOT INTO THE AREA WITHIN TOO MUCH IMPEDANCE FROM
STABILIZATION IN THE WAKE OF THIS LEAD CLUSTER OF SEVERE STORMS.

THIS MAIN WIDESPREAD ACTIVITY...WHICH WILL SPREAD SOUTHWARD THROUGH
THE AREA THIS EVENING...STILL LOOKS TO ORGANIZE FROM VARIOUS
CONVECTIVE CLUSTERS CURRENTLY ACTIVE OVER NORTHERN WISCONSIN AND
WESTERN NORTHERN LOWER MICHIGAN. AS A COLD FRONT AND STRONG UPPER
LEVEL SUPPORT FROM AMPLIFYING UPPER TROUGH WORK INTO THE
REGION...THESE CLUSTERS SHOULD COMBINE INTO A PRETTY SOLID LINE (OR
TWO) OF STORMS AND ACCELERATE THROUGH SOUTHEAST LOWER MICHIGAN FROM
MID TO LATE EVENING. WHILE LATE DAY INSTABILITY...CURRENTLY 2500
J/KG OF MLCAPE...WILL EASE BY THIS TIME...HIGH BULK SHEAR FROM
STRONG WIND FIELD...ALONG WITH GENERAL UPSCALE ORGANIZATION OF THE
MESOSCALE SYSTEM...SHOULD SUPPORT RATHER WIDESPREAD WIND DAMAGE.

AS OF 3 PM...IT APPEARS THE STORM CLUSTER THAT WILL LIKELY BECOME
OUR MAIN EVENT THIS EVENING IS ORGANIZING OVER NORTHERN WISCONSIN AS
THE FULL UPPER SUPPORT OF THE DEEPENING SHORTWAVE TROUGH IS NOW
SPREADING INTO THIS AREA. THIS CURRENT LOCATION SUPPORTS A SLIGHTLY
FASTER ADVANCE INTO THE AREA BY PERHAPS 1 OR 2 HOURS -VS- THE
PREVIOUS FORECAST THINKING. THIS BASICALLY FOCUSES THIS NEXT ROUND
OF SEVERE THUNDERSTORMS AT 23Z-00Z OVER THE FAR NORTHERN CWA TO 01Z-
02Z FLINT INTO NORTHERN METRO DETROIT...AND QUICKLY SOUTH FROM THERE
THE REST OF THE EVENING AS WHAT WILL MOST LIKELY BE A FORWARD
PROPAGATING MCS MATURES AND RACES THROUGH LOWER MICHIGAN.

LONG TERM...

UPPER LOW CENTER WILL SLOWLY TRACK FROM ONTARIO TO QUEBEC MONDAY AND
TUESDAY. THIS WILL KEEP THE NORTHERN AND CENTRAL GREAT LAKES
CONFINED WITHIN COOLER WEST TO NORTHWEST FLOW AROUND THE BACKSIDE OF
THE SYSTEM. COOLER AND QUIETER WEATHER CAN BE EXPECTED FOR THE FIRST
PART OF THE WORK WEEK...ALTHOUGH A FEW SHORTWAVE TROUGHS WILL STILL
PIVOT DOWN ACROSS MICHIGAN. MODELS ARE STILL KEYING IN ON A
SECONDARY COLD FRONT DROPPING DOWN THROUGH NORTHERN AND CENTRAL
LOWER MICHIGAN LATE MONDAY THROUGH THE FIRST PART OF MONDAY NIGHT.
FORECAST CONTINUES TO CARRY A LOW CHANCE OF POPS FROM I-69 NORTH
WHERE MORE MOISTURE WILL BE AVAILABLE AND WHERE COOLER MID-LEVEL AIR
WILL OVERLAP WITH DIURNAL HEATING AHEAD OF THE FRONT. THE SECONDARY
FRONT WILL REMAIN SETTLED OVER CENTRAL MICHIGAN INTO TUESDAY...AND
MAY AGAIN PROVIDE A FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS
TUESDAY AFTERNOON/EVENING AS A SHORTWAVE TROUGH CLIPS ACROSS THE
REGION. CONDITIONS WILL FEEL COOLER WITH DEWPOINTS DROPPING INTO
MORE COMFORTABLE READINGS IN THE 50S...AND AS DAYTIME HIGHS ONLY
REACH INTO THE MID 70S TO LOW 80S MONDAY AND INTO THE 70S ON TUESDAY.

WEDNESDAY THROUGH SUNDAY.

FAIR WEATHER IS STILL ON TRACK FOR WEDNESDAY AS HIGH PRESSURE MOVES
OVER THE REGION. DRY CONDITIONS SHOULD HOLD OVER MOST OF SOUTHEAST
MICHIGAN ON THURSDAY MORNING...WITH EXCEPTION OF THE SOUTHERN MOST
COUNTIES WHERE SCATTERED SHOWERS WILL BEGIN TO POP. CHANCES OF
SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHWARD THROUGH THE
AFTERNOON AND EVENING OFF LOW PUSHING INTO NORTHERN OHIO. CONFIDENCE
AND TIMING ON THIS SYSTEM IS LOW TO MODERATE DUE TO MODEL
INCONSISTENCIES. POTENTIAL FOR SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL LINGER INTO SATURDAY.

MARINE...

STRONG SOUTHWEST WINDS WITH GUSTS OF 25 TO 30 KNOTS WILL CONTINUE
INTO TONIGHT IN ADVANCE OF A COLD FRONT DROPPING THROUGH THE GREAT
LAKES. THE STRONGEST WINDS WILL BE OVER SAGINAW BAY...WHERE
SOUTHWEST WINDS WILL FUNNEL. THE FRONT AND A WARM AND UNSTABLE
AIRMASS PRECEDING IT WILL ALSO PROVIDE ROUNDS OF SHOWERS AND
THUNDERSTORMS THROUGH TONIGHT...SOME OF WHICH WILL BE SEVERE. THE
MOST LIKELY THREAT WITH THUNDERSTORMS WILL BE WIND GUSTS TO 50
KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT
MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE
HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT
THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT
LAKES REGION.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR LHZ421-
     422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR LEZ444.

&&

$$

AVIATION.....CB
SHORT TERM...DG
LONG TERM....HLO/DE
MARINE.......HLO


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




000
FXUS63 KDTX 030525
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
125 AM EDT MON AUG 3 2015


.AVIATION...

LINE OF THUNDERSTORMS HAS SETTLED INTO PORTIONS OF OHIO AND INDIANA.
TRAILING STRATIFORM PRECIPITATION WITH EMBEDDED LIGHTNING WILL
IMPACT THE SOUTHERN TERMINALS OMITTENLY DURING THE FIRST HOUR OR TWO
OF THE TAF CYCLE. RESIDUAL MOISTURE WITH ONSET OF LOW LEVEL COLD AIR
ADVECTION SHOULD ALLOW IFR STRATUS DECK TO FILL IN ACROSS THE
NORTHERN HALF OF THE AREA. OBSERVING PLATFORMS HAVE RECORDED THE IFR
CIGS NOW ITS A QUESTION OF OVERALL DEVELOPING COVERAGE. KEPT CIGS AT
BORDERLINE IFR/MVFR FOR THE DETROIT TERMINALS. DEVELOPING BOUNDARY
LAYER TODAY WILL LEAD TO WEST WINDS OF 10 TO 20 KNOTS. LOSS OF
DAYTIME HEATING AND DRY AIR ADVECTION IS EXPECTED TO LEAD TO
PREDOMINATELY SKC CONDITIONS TONIGHT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN ISOLATED CLOUD TO GROUND LIGHTNING STRIKES BETWEEN 06-
  08Z.

* HIGH FOR CIGS BELOW 5000 FT AGL. LOW CONFIDENCE IN POTENTIAL FOR
  CIGS OF LESS THAN 1000 FT.

&&

.PREV DISCUSSION...ISSUED 325 PM EDT SUN AUG 2 2015

SHORT TERM...THIS AFTERNOON AND TONIGHT

SCATTERED CONVECTION CONTINUES TO BUBBLE OVER FAR NORTHERN CWA ALONG
WEST TO EAST OUTFLOW BOUNDARY STALLED OVER THAT AREA ALONG SOUTHERN
PERIPHERY OF CONVECTIVE CLUSTER TRACK(S) FROM THIS MORNING AND EARLY
AFTERNOON. EXPECT THIS ACTIVITY TO GRADUALLY INCREASE IN COVERAGE
THROUGH THE REST OF THE AFTERNOON...AT LEAST NORTH OF THE INTERSTATE
69 CORRIDOR. GIVEN THE DEGREE OF INSTABILITY ADVECTING INTO AREA FROM
THE WEST AND SOUTHWEST AND FEEDING THIS ACTIVITY...EXPECT SOME OF
THESE STORMS TO BE SEVERE. TO THIS POINT...THIS ACTIVITY HAS HAS
REMAIN CONFINED TO THE SAGINAW VALLEY AND NORTHERN THUMB. IF THIS
REMAINS THE CASE...LATER ACTIVITY THIS EVENING SHOULD HAVE A
STRAIGHT SHOT INTO THE AREA WITHIN TOO MUCH IMPEDANCE FROM
STABILIZATION IN THE WAKE OF THIS LEAD CLUSTER OF SEVERE STORMS.

THIS MAIN WIDESPREAD ACTIVITY...WHICH WILL SPREAD SOUTHWARD THROUGH
THE AREA THIS EVENING...STILL LOOKS TO ORGANIZE FROM VARIOUS
CONVECTIVE CLUSTERS CURRENTLY ACTIVE OVER NORTHERN WISCONSIN AND
WESTERN NORTHERN LOWER MICHIGAN. AS A COLD FRONT AND STRONG UPPER
LEVEL SUPPORT FROM AMPLIFYING UPPER TROUGH WORK INTO THE
REGION...THESE CLUSTERS SHOULD COMBINE INTO A PRETTY SOLID LINE (OR
TWO) OF STORMS AND ACCELERATE THROUGH SOUTHEAST LOWER MICHIGAN FROM
MID TO LATE EVENING. WHILE LATE DAY INSTABILITY...CURRENTLY 2500
J/KG OF MLCAPE...WILL EASE BY THIS TIME...HIGH BULK SHEAR FROM
STRONG WIND FIELD...ALONG WITH GENERAL UPSCALE ORGANIZATION OF THE
MESOSCALE SYSTEM...SHOULD SUPPORT RATHER WIDESPREAD WIND DAMAGE.

AS OF 3 PM...IT APPEARS THE STORM CLUSTER THAT WILL LIKELY BECOME
OUR MAIN EVENT THIS EVENING IS ORGANIZING OVER NORTHERN WISCONSIN AS
THE FULL UPPER SUPPORT OF THE DEEPENING SHORTWAVE TROUGH IS NOW
SPREADING INTO THIS AREA. THIS CURRENT LOCATION SUPPORTS A SLIGHTLY
FASTER ADVANCE INTO THE AREA BY PERHAPS 1 OR 2 HOURS -VS- THE
PREVIOUS FORECAST THINKING. THIS BASICALLY FOCUSES THIS NEXT ROUND
OF SEVERE THUNDERSTORMS AT 23Z-00Z OVER THE FAR NORTHERN CWA TO 01Z-
02Z FLINT INTO NORTHERN METRO DETROIT...AND QUICKLY SOUTH FROM THERE
THE REST OF THE EVENING AS WHAT WILL MOST LIKELY BE A FORWARD
PROPAGATING MCS MATURES AND RACES THROUGH LOWER MICHIGAN.

LONG TERM...

UPPER LOW CENTER WILL SLOWLY TRACK FROM ONTARIO TO QUEBEC MONDAY AND
TUESDAY. THIS WILL KEEP THE NORTHERN AND CENTRAL GREAT LAKES
CONFINED WITHIN COOLER WEST TO NORTHWEST FLOW AROUND THE BACKSIDE OF
THE SYSTEM. COOLER AND QUIETER WEATHER CAN BE EXPECTED FOR THE FIRST
PART OF THE WORK WEEK...ALTHOUGH A FEW SHORTWAVE TROUGHS WILL STILL
PIVOT DOWN ACROSS MICHIGAN. MODELS ARE STILL KEYING IN ON A
SECONDARY COLD FRONT DROPPING DOWN THROUGH NORTHERN AND CENTRAL
LOWER MICHIGAN LATE MONDAY THROUGH THE FIRST PART OF MONDAY NIGHT.
FORECAST CONTINUES TO CARRY A LOW CHANCE OF POPS FROM I-69 NORTH
WHERE MORE MOISTURE WILL BE AVAILABLE AND WHERE COOLER MID-LEVEL AIR
WILL OVERLAP WITH DIURNAL HEATING AHEAD OF THE FRONT. THE SECONDARY
FRONT WILL REMAIN SETTLED OVER CENTRAL MICHIGAN INTO TUESDAY...AND
MAY AGAIN PROVIDE A FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS
TUESDAY AFTERNOON/EVENING AS A SHORTWAVE TROUGH CLIPS ACROSS THE
REGION. CONDITIONS WILL FEEL COOLER WITH DEWPOINTS DROPPING INTO
MORE COMFORTABLE READINGS IN THE 50S...AND AS DAYTIME HIGHS ONLY
REACH INTO THE MID 70S TO LOW 80S MONDAY AND INTO THE 70S ON TUESDAY.

WEDNESDAY THROUGH SUNDAY.

FAIR WEATHER IS STILL ON TRACK FOR WEDNESDAY AS HIGH PRESSURE MOVES
OVER THE REGION. DRY CONDITIONS SHOULD HOLD OVER MOST OF SOUTHEAST
MICHIGAN ON THURSDAY MORNING...WITH EXCEPTION OF THE SOUTHERN MOST
COUNTIES WHERE SCATTERED SHOWERS WILL BEGIN TO POP. CHANCES OF
SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHWARD THROUGH THE
AFTERNOON AND EVENING OFF LOW PUSHING INTO NORTHERN OHIO. CONFIDENCE
AND TIMING ON THIS SYSTEM IS LOW TO MODERATE DUE TO MODEL
INCONSISTENCIES. POTENTIAL FOR SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL LINGER INTO SATURDAY.

MARINE...

STRONG SOUTHWEST WINDS WITH GUSTS OF 25 TO 30 KNOTS WILL CONTINUE
INTO TONIGHT IN ADVANCE OF A COLD FRONT DROPPING THROUGH THE GREAT
LAKES. THE STRONGEST WINDS WILL BE OVER SAGINAW BAY...WHERE
SOUTHWEST WINDS WILL FUNNEL. THE FRONT AND A WARM AND UNSTABLE
AIRMASS PRECEDING IT WILL ALSO PROVIDE ROUNDS OF SHOWERS AND
THUNDERSTORMS THROUGH TONIGHT...SOME OF WHICH WILL BE SEVERE. THE
MOST LIKELY THREAT WITH THUNDERSTORMS WILL BE WIND GUSTS TO 50
KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT
MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE
HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT
THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT
LAKES REGION.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR LHZ421-
     422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR LEZ444.

&&

$$

AVIATION.....CB
SHORT TERM...DG
LONG TERM....HLO/DE
MARINE.......HLO


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





000
FXUS63 KDTX 022304
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
704 PM EDT SUN AUG 2 2015


.AVIATION...

THUNDERSTORMS ARE SAGGING SOUTHWARD INTO THE AREA AND WILL AFFECT
MBS AS THE FORECAST PERIOD BEGINS AND THEN SETTLE SOUTH THROUGH THE
REMAINDER OF THE TERMINALS THROUGH ABOUT 05Z OR SO. EXPECT IFR/MVFR
CONDITIONS IN THE HEAVY RAIN THAT OCCURS...WITH GUSTY WINDS WILL THE
STRONGEST STORMS. IN FACT...POCKETS OF SEVERE WIND GUSTS TO 50 KNOTS
IS NOT OUT OF THE QUESTION. MVFR/LOWER VFR CIGS MAY PERSIST DURING
THE NIGHT WITH A STRAY SHRA OR TWO AS UPPER LEVEL TROUGH PIVOTS
THROUGH...BUT GENERALLY EXPECT A TRANSITION BACK TO VFR INTO MONDAY.

FOR DTW...MOST PROBABLE TIME FOR THUNDERSTORMS REMAINS IN THE 02Z-
06Z TIME FRAME AS LINE OF CONVECTION WORKS INTO AREA IN ADVANCE OF
COLD FRONT. THIS FRONT WILL THEN CLEAR THE AREA LATER TONIGHT INTO
MONDAY MORNING AND BRING VFR CONDITIONS.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS 00Z-03Z...THEN MEDIUM 03Z-06Z TONIGHT.

&&

.PREV DISCUSSION...ISSUED 325 PM EDT SUN AUG 2 2015

SHORT TERM...THIS AFTERNOON AND TONIGHT

SCATTERED CONVECTION CONTINUES TO BUBBLE OVER FAR NORTHERN CWA ALONG
WEST TO EAST OUTFLOW BOUNDARY STALLED OVER THAT AREA ALONG SOUTHERN
PERIPHERY OF CONVECTIVE CLUSTER TRACK(S) FROM THIS MORNING AND EARLY
AFTERNOON. EXPECT THIS ACTIVITY TO GRADUALLY INCREASE IN COVERAGE
THROUGH THE REST OF THE AFTERNOON...AT LEAST NORTH OF THE INTERSTATE
69 CORRIDOR. GIVEN THE DEGREE OF INSTABILITY ADVECTING INTO AREA FROM
THE WEST AND SOUTHWEST AND FEEDING THIS ACTIVITY...EXPECT SOME OF
THESE STORMS TO BE SEVERE. TO THIS POINT...THIS ACTIVITY HAS HAS
REMAIN CONFINED TO THE SAGINAW VALLEY AND NORTHERN THUMB. IF THIS
REMAINS THE CASE...LATER ACTIVITY THIS EVENING SHOULD HAVE A
STRAIGHT SHOT INTO THE AREA WITHIN TOO MUCH IMPEDANCE FROM
STABILIZATION IN THE WAKE OF THIS LEAD CLUSTER OF SEVERE STORMS.

THIS MAIN WIDESPREAD ACTIVITY...WHICH WILL SPREAD SOUTHWARD THROUGH
THE AREA THIS EVENING...STILL LOOKS TO ORGANIZE FROM VARIOUS
CONVECTIVE CLUSTERS CURRENTLY ACTIVE OVER NORTHERN WISCONSIN AND
WESTERN NORTHERN LOWER MICHIGAN. AS A COLD FRONT AND STRONG UPPER
LEVEL SUPPORT FROM AMPLIFYING UPPER TROUGH WORK INTO THE
REGION...THESE CLUSTERS SHOULD COMBINE INTO A PRETTY SOLID LINE (OR
TWO) OF STORMS AND ACCELERATE THROUGH SOUTHEAST LOWER MICHIGAN FROM
MID TO LATE EVENING. WHILE LATE DAY INSTABILITY...CURRENTLY 2500
J/KG OF MLCAPE...WILL EASE BY THIS TIME...HIGH BULK SHEAR FROM
STRONG WIND FIELD...ALONG WITH GENERAL UPSCALE ORGANIZATION OF THE
MESOSCALE SYSTEM...SHOULD SUPPORT RATHER WIDESPREAD WIND DAMAGE.

AS OF 3 PM...IT APPEARS THE STORM CLUSTER THAT WILL LIKELY BECOME
OUR MAIN EVENT THIS EVENING IS ORGANIZING OVER NORTHERN WISCONSIN AS
THE FULL UPPER SUPPORT OF THE DEEPENING SHORTWAVE TROUGH IS NOW
SPREADING INTO THIS AREA. THIS CURRENT LOCATION SUPPORTS A SLIGHTLY
FASTER ADVANCE INTO THE AREA BY PERHAPS 1 OR 2 HOURS -VS- THE
PREVIOUS FORECAST THINKING. THIS BASICALLY FOCUSES THIS NEXT ROUND
OF SEVERE THUNDERSTORMS AT 23Z-00Z OVER THE FAR NORTHERN CWA TO 01Z-
02Z FLINT INTO NORTHERN METRO DETROIT...AND QUICKLY SOUTH FROM THERE
THE REST OF THE EVENING AS WHAT WILL MOST LIKELY BE A FORWARD
PROPAGATING MCS MATURES AND RACES THROUGH LOWER MICHIGAN.

LONG TERM...

UPPER LOW CENTER WILL SLOWLY TRACK FROM ONTARIO TO QUEBEC MONDAY AND
TUESDAY. THIS WILL KEEP THE NORTHERN AND CENTRAL GREAT LAKES
CONFINED WITHIN COOLER WEST TO NORTHWEST FLOW AROUND THE BACKSIDE OF
THE SYSTEM. COOLER AND QUIETER WEATHER CAN BE EXPECTED FOR THE FIRST
PART OF THE WORK WEEK...ALTHOUGH A FEW SHORTWAVE TROUGHS WILL STILL
PIVOT DOWN ACROSS MICHIGAN. MODELS ARE STILL KEYING IN ON A
SECONDARY COLD FRONT DROPPING DOWN THROUGH NORTHERN AND CENTRAL
LOWER MICHIGAN LATE MONDAY THROUGH THE FIRST PART OF MONDAY NIGHT.
FORECAST CONTINUES TO CARRY A LOW CHANCE OF POPS FROM I-69 NORTH
WHERE MORE MOISTURE WILL BE AVAILABLE AND WHERE COOLER MID-LEVEL AIR
WILL OVERLAP WITH DIURNAL HEATING AHEAD OF THE FRONT. THE SECONDARY
FRONT WILL REMAIN SETTLED OVER CENTRAL MICHIGAN INTO TUESDAY...AND
MAY AGAIN PROVIDE A FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS
TUESDAY AFTERNOON/EVENING AS A SHORTWAVE TROUGH CLIPS ACROSS THE
REGION. CONDITIONS WILL FEEL COOLER WITH DEWPOINTS DROPPING INTO
MORE COMFORTABLE READINGS IN THE 50S...AND AS DAYTIME HIGHS ONLY
REACH INTO THE MID 70S TO LOW 80S MONDAY AND INTO THE 70S ON TUESDAY.

WEDNESDAY THROUGH SUNDAY.

FAIR WEATHER IS STILL ON TRACK FOR WEDNESDAY AS HIGH PRESSURE MOVES
OVER THE REGION. DRY CONDITIONS SHOULD HOLD OVER MOST OF SOUTHEAST
MICHIGAN ON THURSDAY MORNING...WITH EXCEPTION OF THE SOUTHERN MOST
COUNTIES WHERE SCATTERED SHOWERS WILL BEGIN TO POP. CHANCES OF
SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHWARD THROUGH THE
AFTERNOON AND EVENING OFF LOW PUSHING INTO NORTHERN OHIO. CONFIDENCE
AND TIMING ON THIS SYSTEM IS LOW TO MODERATE DUE TO MODEL
INCONSISTENCIES. POTENTIAL FOR SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL LINGER INTO SATURDAY.

MARINE...

STRONG SOUTHWEST WINDS WITH GUSTS OF 25 TO 30 KNOTS WILL CONTINUE
INTO TONIGHT IN ADVANCE OF A COLD FRONT DROPPING THROUGH THE GREAT
LAKES. THE STRONGEST WINDS WILL BE OVER SAGINAW BAY...WHERE
SOUTHWEST WINDS WILL FUNNEL. THE FRONT AND A WARM AND UNSTABLE
AIRMASS PRECEDING IT WILL ALSO PROVIDE ROUNDS OF SHOWERS AND
THUNDERSTORMS THROUGH TONIGHT...SOME OF WHICH WILL BE SEVERE. THE
MOST LIKELY THREAT WITH THUNDERSTORMS WILL BE WIND GUSTS TO 50
KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT
MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE
HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT
THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT
LAKES REGION.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

AVIATION.....DT
SHORT TERM...DG
LONG TERM....HLO/DE
MARINE.......HLO


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





000
FXUS63 KDTX 022304
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
704 PM EDT SUN AUG 2 2015


.AVIATION...

THUNDERSTORMS ARE SAGGING SOUTHWARD INTO THE AREA AND WILL AFFECT
MBS AS THE FORECAST PERIOD BEGINS AND THEN SETTLE SOUTH THROUGH THE
REMAINDER OF THE TERMINALS THROUGH ABOUT 05Z OR SO. EXPECT IFR/MVFR
CONDITIONS IN THE HEAVY RAIN THAT OCCURS...WITH GUSTY WINDS WILL THE
STRONGEST STORMS. IN FACT...POCKETS OF SEVERE WIND GUSTS TO 50 KNOTS
IS NOT OUT OF THE QUESTION. MVFR/LOWER VFR CIGS MAY PERSIST DURING
THE NIGHT WITH A STRAY SHRA OR TWO AS UPPER LEVEL TROUGH PIVOTS
THROUGH...BUT GENERALLY EXPECT A TRANSITION BACK TO VFR INTO MONDAY.

FOR DTW...MOST PROBABLE TIME FOR THUNDERSTORMS REMAINS IN THE 02Z-
06Z TIME FRAME AS LINE OF CONVECTION WORKS INTO AREA IN ADVANCE OF
COLD FRONT. THIS FRONT WILL THEN CLEAR THE AREA LATER TONIGHT INTO
MONDAY MORNING AND BRING VFR CONDITIONS.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS 00Z-03Z...THEN MEDIUM 03Z-06Z TONIGHT.

&&

.PREV DISCUSSION...ISSUED 325 PM EDT SUN AUG 2 2015

SHORT TERM...THIS AFTERNOON AND TONIGHT

SCATTERED CONVECTION CONTINUES TO BUBBLE OVER FAR NORTHERN CWA ALONG
WEST TO EAST OUTFLOW BOUNDARY STALLED OVER THAT AREA ALONG SOUTHERN
PERIPHERY OF CONVECTIVE CLUSTER TRACK(S) FROM THIS MORNING AND EARLY
AFTERNOON. EXPECT THIS ACTIVITY TO GRADUALLY INCREASE IN COVERAGE
THROUGH THE REST OF THE AFTERNOON...AT LEAST NORTH OF THE INTERSTATE
69 CORRIDOR. GIVEN THE DEGREE OF INSTABILITY ADVECTING INTO AREA FROM
THE WEST AND SOUTHWEST AND FEEDING THIS ACTIVITY...EXPECT SOME OF
THESE STORMS TO BE SEVERE. TO THIS POINT...THIS ACTIVITY HAS HAS
REMAIN CONFINED TO THE SAGINAW VALLEY AND NORTHERN THUMB. IF THIS
REMAINS THE CASE...LATER ACTIVITY THIS EVENING SHOULD HAVE A
STRAIGHT SHOT INTO THE AREA WITHIN TOO MUCH IMPEDANCE FROM
STABILIZATION IN THE WAKE OF THIS LEAD CLUSTER OF SEVERE STORMS.

THIS MAIN WIDESPREAD ACTIVITY...WHICH WILL SPREAD SOUTHWARD THROUGH
THE AREA THIS EVENING...STILL LOOKS TO ORGANIZE FROM VARIOUS
CONVECTIVE CLUSTERS CURRENTLY ACTIVE OVER NORTHERN WISCONSIN AND
WESTERN NORTHERN LOWER MICHIGAN. AS A COLD FRONT AND STRONG UPPER
LEVEL SUPPORT FROM AMPLIFYING UPPER TROUGH WORK INTO THE
REGION...THESE CLUSTERS SHOULD COMBINE INTO A PRETTY SOLID LINE (OR
TWO) OF STORMS AND ACCELERATE THROUGH SOUTHEAST LOWER MICHIGAN FROM
MID TO LATE EVENING. WHILE LATE DAY INSTABILITY...CURRENTLY 2500
J/KG OF MLCAPE...WILL EASE BY THIS TIME...HIGH BULK SHEAR FROM
STRONG WIND FIELD...ALONG WITH GENERAL UPSCALE ORGANIZATION OF THE
MESOSCALE SYSTEM...SHOULD SUPPORT RATHER WIDESPREAD WIND DAMAGE.

AS OF 3 PM...IT APPEARS THE STORM CLUSTER THAT WILL LIKELY BECOME
OUR MAIN EVENT THIS EVENING IS ORGANIZING OVER NORTHERN WISCONSIN AS
THE FULL UPPER SUPPORT OF THE DEEPENING SHORTWAVE TROUGH IS NOW
SPREADING INTO THIS AREA. THIS CURRENT LOCATION SUPPORTS A SLIGHTLY
FASTER ADVANCE INTO THE AREA BY PERHAPS 1 OR 2 HOURS -VS- THE
PREVIOUS FORECAST THINKING. THIS BASICALLY FOCUSES THIS NEXT ROUND
OF SEVERE THUNDERSTORMS AT 23Z-00Z OVER THE FAR NORTHERN CWA TO 01Z-
02Z FLINT INTO NORTHERN METRO DETROIT...AND QUICKLY SOUTH FROM THERE
THE REST OF THE EVENING AS WHAT WILL MOST LIKELY BE A FORWARD
PROPAGATING MCS MATURES AND RACES THROUGH LOWER MICHIGAN.

LONG TERM...

UPPER LOW CENTER WILL SLOWLY TRACK FROM ONTARIO TO QUEBEC MONDAY AND
TUESDAY. THIS WILL KEEP THE NORTHERN AND CENTRAL GREAT LAKES
CONFINED WITHIN COOLER WEST TO NORTHWEST FLOW AROUND THE BACKSIDE OF
THE SYSTEM. COOLER AND QUIETER WEATHER CAN BE EXPECTED FOR THE FIRST
PART OF THE WORK WEEK...ALTHOUGH A FEW SHORTWAVE TROUGHS WILL STILL
PIVOT DOWN ACROSS MICHIGAN. MODELS ARE STILL KEYING IN ON A
SECONDARY COLD FRONT DROPPING DOWN THROUGH NORTHERN AND CENTRAL
LOWER MICHIGAN LATE MONDAY THROUGH THE FIRST PART OF MONDAY NIGHT.
FORECAST CONTINUES TO CARRY A LOW CHANCE OF POPS FROM I-69 NORTH
WHERE MORE MOISTURE WILL BE AVAILABLE AND WHERE COOLER MID-LEVEL AIR
WILL OVERLAP WITH DIURNAL HEATING AHEAD OF THE FRONT. THE SECONDARY
FRONT WILL REMAIN SETTLED OVER CENTRAL MICHIGAN INTO TUESDAY...AND
MAY AGAIN PROVIDE A FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS
TUESDAY AFTERNOON/EVENING AS A SHORTWAVE TROUGH CLIPS ACROSS THE
REGION. CONDITIONS WILL FEEL COOLER WITH DEWPOINTS DROPPING INTO
MORE COMFORTABLE READINGS IN THE 50S...AND AS DAYTIME HIGHS ONLY
REACH INTO THE MID 70S TO LOW 80S MONDAY AND INTO THE 70S ON TUESDAY.

WEDNESDAY THROUGH SUNDAY.

FAIR WEATHER IS STILL ON TRACK FOR WEDNESDAY AS HIGH PRESSURE MOVES
OVER THE REGION. DRY CONDITIONS SHOULD HOLD OVER MOST OF SOUTHEAST
MICHIGAN ON THURSDAY MORNING...WITH EXCEPTION OF THE SOUTHERN MOST
COUNTIES WHERE SCATTERED SHOWERS WILL BEGIN TO POP. CHANCES OF
SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHWARD THROUGH THE
AFTERNOON AND EVENING OFF LOW PUSHING INTO NORTHERN OHIO. CONFIDENCE
AND TIMING ON THIS SYSTEM IS LOW TO MODERATE DUE TO MODEL
INCONSISTENCIES. POTENTIAL FOR SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL LINGER INTO SATURDAY.

MARINE...

STRONG SOUTHWEST WINDS WITH GUSTS OF 25 TO 30 KNOTS WILL CONTINUE
INTO TONIGHT IN ADVANCE OF A COLD FRONT DROPPING THROUGH THE GREAT
LAKES. THE STRONGEST WINDS WILL BE OVER SAGINAW BAY...WHERE
SOUTHWEST WINDS WILL FUNNEL. THE FRONT AND A WARM AND UNSTABLE
AIRMASS PRECEDING IT WILL ALSO PROVIDE ROUNDS OF SHOWERS AND
THUNDERSTORMS THROUGH TONIGHT...SOME OF WHICH WILL BE SEVERE. THE
MOST LIKELY THREAT WITH THUNDERSTORMS WILL BE WIND GUSTS TO 50
KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT
MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE
HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT
THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT
LAKES REGION.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

AVIATION.....DT
SHORT TERM...DG
LONG TERM....HLO/DE
MARINE.......HLO


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




000
FXUS63 KDTX 021925
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
325 PM EDT SUN AUG 2 2015

.SHORT TERM...THIS AFTERNOON AND TONIGHT

SCATTERED CONVECTION CONTINUES TO BUBBLE OVER FAR NORTHERN CWA ALONG
WEST TO EAST OUTFLOW BOUNDARY STALLED OVER THAT AREA ALONG SOUTHERN
PERIPHERY OF CONVECTIVE CLUSTER TRACK(S) FROM THIS MORNING AND EARLY
AFTERNOON. EXPECT THIS ACTIVITY TO GRADUALLY INCREASE IN COVERAGE
THROUGH THE REST OF THE AFTERNOON...AT LEAST NORTH OF THE INTERSTATE
69 CORRIDOR. GIVEN THE DEGREE OF INSTABILITY ADVECTING INTO AREA FROM
THE WEST AND SOUTHWEST AND FEEDING THIS ACTIVITY...EXPECT SOME OF
THESE STORMS TO BE SEVERE. TO THIS POINT...THIS ACTIVITY HAS HAS
REMAIN CONFINED TO THE SAGINAW VALLEY AND NORTHERN THUMB. IF THIS
REMAINS THE CASE...LATER ACTIVITY THIS EVENING SHOULD HAVE A
STRAIGHT SHOT INTO THE AREA WITHIN TOO MUCH IMPEDANCE FROM
STABILIZATION IN THE WAKE OF THIS LEAD CLUSTER OF SEVERE STORMS.

THIS MAIN WIDESPREAD ACTIVITY...WHICH WILL SPREAD SOUTHWARD THROUGH
THE AREA THIS EVENING...STILL LOOKS TO ORGANIZE FROM VARIOUS
CONVECTIVE CLUSTERS CURRENTLY ACTIVE OVER NORTHERN WISCONSIN AND
WESTERN NORTHERN LOWER MICHIGAN. AS A COLD FRONT AND STRONG UPPER
LEVEL SUPPORT FROM AMPLIFYING UPPER TROUGH WORK INTO THE
REGION...THESE CLUSTERS SHOULD COMBINE INTO A PRETTY SOLID LINE (OR
TWO) OF STORMS AND ACCELERATE THROUGH SOUTHEAST LOWER MICHIGAN FROM
MID TO LATE EVENING. WHILE LATE DAY INSTABILITY...CURRENTLY 2500
J/KG OF MLCAPE...WILL EASE BY THIS TIME...HIGH BULK SHEAR FROM
STRONG WIND FIELD...ALONG WITH GENERAL UPSCALE ORGANIZATION OF THE
MESOSCALE SYSTEM...SHOULD SUPPORT RATHER WIDESPREAD WIND DAMAGE.

AS OF 3 PM...IT APPEARS THE STORM CLUSTER THAT WILL LIKELY BECOME
OUR MAIN EVENT THIS EVENING IS ORGANIZING OVER NORTHERN WISCONSIN AS
THE FULL UPPER SUPPORT OF THE DEEPENING SHORTWAVE TROUGH IS NOW
SPREADING INTO THIS AREA. THIS CURRENT LOCATION SUPPORTS A SLIGHTLY
FASTER ADVANCE INTO THE AREA BY PERHAPS 1 OR 2 HOURS -VS- THE
PREVIOUS FORECAST THINKING. THIS BASICALLY FOCUSES THIS NEXT ROUND
OF SEVERE THUNDERSTORMS AT 23Z-00Z OVER THE FAR NORTHERN CWA TO 01Z-
02Z FLINT INTO NORTHERN METRO DETROIT...AND QUICKLY SOUTH FROM THERE
THE REST OF THE EVENING AS WHAT WILL MOST LIKELY BE A FORWARD
PROPAGATING MCS MATURES AND RACES THROUGH LOWER MICHIGAN.

&&

.LONG TERM...

UPPER LOW CENTER WILL SLOWLY TRACK FROM ONTARIO TO QUEBEC MONDAY AND
TUESDAY. THIS WILL KEEP THE NORTHERN AND CENTRAL GREAT LAKES
CONFINED WITHIN COOLER WEST TO NORTHWEST FLOW AROUND THE BACKSIDE OF
THE SYSTEM. COOLER AND QUIETER WEATHER CAN BE EXPECTED FOR THE FIRST
PART OF THE WORK WEEK...ALTHOUGH A FEW SHORTWAVE TROUGHS WILL STILL
PIVOT DOWN ACROSS MICHIGAN. MODELS ARE STILL KEYING IN ON A
SECONDARY COLD FRONT DROPPING DOWN THROUGH NORTHERN AND CENTRAL
LOWER MICHIGAN LATE MONDAY THROUGH THE FIRST PART OF MONDAY NIGHT.
FORECAST CONTINUES TO CARRY A LOW CHANCE OF POPS FROM I-69 NORTH
WHERE MORE MOISTURE WILL BE AVAILABLE AND WHERE COOLER MID-LEVEL AIR
WILL OVERLAP WITH DIURNAL HEATING AHEAD OF THE FRONT. THE SECONDARY
FRONT WILL REMAIN SETTLED OVER CENTRAL MICHIGAN INTO TUESDAY...AND
MAY AGAIN PROVIDE A FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS
TUESDAY AFTERNOON/EVENING AS A SHORTWAVE TROUGH CLIPS ACROSS THE
REGION. CONDITIONS WILL FEEL COOLER WITH DEWPOINTS DROPPING INTO
MORE COMFORTABLE READINGS IN THE 50S...AND AS DAYTIME HIGHS ONLY
REACH INTO THE MID 70S TO LOW 80S MONDAY AND INTO THE 70S ON TUESDAY.

WEDNESDAY THROUGH SUNDAY.

FAIR WEATHER IS STILL ON TRACK FOR WEDNESDAY AS HIGH PRESSURE MOVES
OVER THE REGION. DRY CONDITIONS SHOULD HOLD OVER MOST OF SOUTHEAST
MICHIGAN ON THURSDAY MORNING...WITH EXCEPTION OF THE SOUTHERN MOST
COUNTIES WHERE SCATTERED SHOWERS WILL BEGIN TO POP. CHANCES OF
SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHWARD THROUGH THE
AFTERNOON AND EVENING OFF LOW PUSHING INTO NORTHERN OHIO. CONFIDENCE
AND TIMING ON THIS SYSTEM IS LOW TO MODERATE DUE TO MODEL
INCONSISTENCIES. POTENTIAL FOR SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL LINGER INTO SATURDAY.

&&

.MARINE...

STRONG SOUTHWEST WINDS WITH GUSTS OF 25 TO 30 KNOTS WILL CONTINUE
INTO TONIGHT IN ADVANCE OF A COLD FRONT DROPPING THROUGH THE GREAT
LAKES. THE STRONGEST WINDS WILL BE OVER SAGINAW BAY...WHERE
SOUTHWEST WINDS WILL FUNNEL. THE FRONT AND A WARM AND UNSTABLE
AIRMASS PRECEDING IT WILL ALSO PROVIDE ROUNDS OF SHOWERS AND
THUNDERSTORMS THROUGH TONIGHT...SOME OF WHICH WILL BE SEVERE. THE
MOST LIKELY THREAT WITH THUNDERSTORMS WILL BE WIND GUSTS TO 50
KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT
MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE
HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT
THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT
LAKES REGION.

&&

.AVIATION...ISSUED 146 PM EDT SUN AUG 2 2015

THUNDERSTORMS TO THE NORTH SHOULD CONGEAL AND DROP SOUTH THROUGH
AREA THIS EVENING AS A COLD FRONT DROPS SOUTH THROUGH THE CENTRAL
GREAT LAKES. EXPECT A DECENT CHANCE OF A POCKETS OF SEVERE WEATHER
WITHIN THIS EXPECTED AREA OF THUNDERSTORMS...WHICH WILL MOST LIKELY
PROGRESS FROM MBS AT 00Z-01Z TO THE I-94 TERMINALS BY 03Z-05Z AND
THEN EXIT SOUTH OF WHOLE AREA AFTER 06-07Z. OTHERWISE THAN PATCHY
LATE NIGHT FOG TONIGHT...VFR CONDITIONS SHOULD...ONCE AGAIN...BE THE
RULE ONCE THE STORMY WEATHER ENDS TONIGHT.

FOR DTW...MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE
OF APPROACHING COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

SHORT TERM...DG
LONG TERM....HLO/DE
MARINE.......HLO
AVIATION.....DG


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




000
FXUS63 KDTX 021925
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
325 PM EDT SUN AUG 2 2015

.SHORT TERM...THIS AFTERNOON AND TONIGHT

SCATTERED CONVECTION CONTINUES TO BUBBLE OVER FAR NORTHERN CWA ALONG
WEST TO EAST OUTFLOW BOUNDARY STALLED OVER THAT AREA ALONG SOUTHERN
PERIPHERY OF CONVECTIVE CLUSTER TRACK(S) FROM THIS MORNING AND EARLY
AFTERNOON. EXPECT THIS ACTIVITY TO GRADUALLY INCREASE IN COVERAGE
THROUGH THE REST OF THE AFTERNOON...AT LEAST NORTH OF THE INTERSTATE
69 CORRIDOR. GIVEN THE DEGREE OF INSTABILITY ADVECTING INTO AREA FROM
THE WEST AND SOUTHWEST AND FEEDING THIS ACTIVITY...EXPECT SOME OF
THESE STORMS TO BE SEVERE. TO THIS POINT...THIS ACTIVITY HAS HAS
REMAIN CONFINED TO THE SAGINAW VALLEY AND NORTHERN THUMB. IF THIS
REMAINS THE CASE...LATER ACTIVITY THIS EVENING SHOULD HAVE A
STRAIGHT SHOT INTO THE AREA WITHIN TOO MUCH IMPEDANCE FROM
STABILIZATION IN THE WAKE OF THIS LEAD CLUSTER OF SEVERE STORMS.

THIS MAIN WIDESPREAD ACTIVITY...WHICH WILL SPREAD SOUTHWARD THROUGH
THE AREA THIS EVENING...STILL LOOKS TO ORGANIZE FROM VARIOUS
CONVECTIVE CLUSTERS CURRENTLY ACTIVE OVER NORTHERN WISCONSIN AND
WESTERN NORTHERN LOWER MICHIGAN. AS A COLD FRONT AND STRONG UPPER
LEVEL SUPPORT FROM AMPLIFYING UPPER TROUGH WORK INTO THE
REGION...THESE CLUSTERS SHOULD COMBINE INTO A PRETTY SOLID LINE (OR
TWO) OF STORMS AND ACCELERATE THROUGH SOUTHEAST LOWER MICHIGAN FROM
MID TO LATE EVENING. WHILE LATE DAY INSTABILITY...CURRENTLY 2500
J/KG OF MLCAPE...WILL EASE BY THIS TIME...HIGH BULK SHEAR FROM
STRONG WIND FIELD...ALONG WITH GENERAL UPSCALE ORGANIZATION OF THE
MESOSCALE SYSTEM...SHOULD SUPPORT RATHER WIDESPREAD WIND DAMAGE.

AS OF 3 PM...IT APPEARS THE STORM CLUSTER THAT WILL LIKELY BECOME
OUR MAIN EVENT THIS EVENING IS ORGANIZING OVER NORTHERN WISCONSIN AS
THE FULL UPPER SUPPORT OF THE DEEPENING SHORTWAVE TROUGH IS NOW
SPREADING INTO THIS AREA. THIS CURRENT LOCATION SUPPORTS A SLIGHTLY
FASTER ADVANCE INTO THE AREA BY PERHAPS 1 OR 2 HOURS -VS- THE
PREVIOUS FORECAST THINKING. THIS BASICALLY FOCUSES THIS NEXT ROUND
OF SEVERE THUNDERSTORMS AT 23Z-00Z OVER THE FAR NORTHERN CWA TO 01Z-
02Z FLINT INTO NORTHERN METRO DETROIT...AND QUICKLY SOUTH FROM THERE
THE REST OF THE EVENING AS WHAT WILL MOST LIKELY BE A FORWARD
PROPAGATING MCS MATURES AND RACES THROUGH LOWER MICHIGAN.

&&

.LONG TERM...

UPPER LOW CENTER WILL SLOWLY TRACK FROM ONTARIO TO QUEBEC MONDAY AND
TUESDAY. THIS WILL KEEP THE NORTHERN AND CENTRAL GREAT LAKES
CONFINED WITHIN COOLER WEST TO NORTHWEST FLOW AROUND THE BACKSIDE OF
THE SYSTEM. COOLER AND QUIETER WEATHER CAN BE EXPECTED FOR THE FIRST
PART OF THE WORK WEEK...ALTHOUGH A FEW SHORTWAVE TROUGHS WILL STILL
PIVOT DOWN ACROSS MICHIGAN. MODELS ARE STILL KEYING IN ON A
SECONDARY COLD FRONT DROPPING DOWN THROUGH NORTHERN AND CENTRAL
LOWER MICHIGAN LATE MONDAY THROUGH THE FIRST PART OF MONDAY NIGHT.
FORECAST CONTINUES TO CARRY A LOW CHANCE OF POPS FROM I-69 NORTH
WHERE MORE MOISTURE WILL BE AVAILABLE AND WHERE COOLER MID-LEVEL AIR
WILL OVERLAP WITH DIURNAL HEATING AHEAD OF THE FRONT. THE SECONDARY
FRONT WILL REMAIN SETTLED OVER CENTRAL MICHIGAN INTO TUESDAY...AND
MAY AGAIN PROVIDE A FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS
TUESDAY AFTERNOON/EVENING AS A SHORTWAVE TROUGH CLIPS ACROSS THE
REGION. CONDITIONS WILL FEEL COOLER WITH DEWPOINTS DROPPING INTO
MORE COMFORTABLE READINGS IN THE 50S...AND AS DAYTIME HIGHS ONLY
REACH INTO THE MID 70S TO LOW 80S MONDAY AND INTO THE 70S ON TUESDAY.

WEDNESDAY THROUGH SUNDAY.

FAIR WEATHER IS STILL ON TRACK FOR WEDNESDAY AS HIGH PRESSURE MOVES
OVER THE REGION. DRY CONDITIONS SHOULD HOLD OVER MOST OF SOUTHEAST
MICHIGAN ON THURSDAY MORNING...WITH EXCEPTION OF THE SOUTHERN MOST
COUNTIES WHERE SCATTERED SHOWERS WILL BEGIN TO POP. CHANCES OF
SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHWARD THROUGH THE
AFTERNOON AND EVENING OFF LOW PUSHING INTO NORTHERN OHIO. CONFIDENCE
AND TIMING ON THIS SYSTEM IS LOW TO MODERATE DUE TO MODEL
INCONSISTENCIES. POTENTIAL FOR SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL LINGER INTO SATURDAY.

&&

.MARINE...

STRONG SOUTHWEST WINDS WITH GUSTS OF 25 TO 30 KNOTS WILL CONTINUE
INTO TONIGHT IN ADVANCE OF A COLD FRONT DROPPING THROUGH THE GREAT
LAKES. THE STRONGEST WINDS WILL BE OVER SAGINAW BAY...WHERE
SOUTHWEST WINDS WILL FUNNEL. THE FRONT AND A WARM AND UNSTABLE
AIRMASS PRECEDING IT WILL ALSO PROVIDE ROUNDS OF SHOWERS AND
THUNDERSTORMS THROUGH TONIGHT...SOME OF WHICH WILL BE SEVERE. THE
MOST LIKELY THREAT WITH THUNDERSTORMS WILL BE WIND GUSTS TO 50
KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT
MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE
HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT
THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT
LAKES REGION.

&&

.AVIATION...ISSUED 146 PM EDT SUN AUG 2 2015

THUNDERSTORMS TO THE NORTH SHOULD CONGEAL AND DROP SOUTH THROUGH
AREA THIS EVENING AS A COLD FRONT DROPS SOUTH THROUGH THE CENTRAL
GREAT LAKES. EXPECT A DECENT CHANCE OF A POCKETS OF SEVERE WEATHER
WITHIN THIS EXPECTED AREA OF THUNDERSTORMS...WHICH WILL MOST LIKELY
PROGRESS FROM MBS AT 00Z-01Z TO THE I-94 TERMINALS BY 03Z-05Z AND
THEN EXIT SOUTH OF WHOLE AREA AFTER 06-07Z. OTHERWISE THAN PATCHY
LATE NIGHT FOG TONIGHT...VFR CONDITIONS SHOULD...ONCE AGAIN...BE THE
RULE ONCE THE STORMY WEATHER ENDS TONIGHT.

FOR DTW...MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE
OF APPROACHING COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

SHORT TERM...DG
LONG TERM....HLO/DE
MARINE.......HLO
AVIATION.....DG


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





000
FXUS63 KDTX 021746
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
146 PM EDT SUN AUG 2 2015


.AVIATION...

THUNDERSTORMS TO THE NORTH SHOULD CONGEAL AND DROP SOUTH THROUGH
AREA THIS EVENING AS A COLD FRONT DROPS SOUTH THROUGH THE CENTRAL
GREAT LAKES. EXPECT A DECENT CHANCE OF A POCKETS OF SEVERE WEATHER
WITHIN THIS EXPECTED AREA OF THUNDERSTORMS...WHICH WILL MOST LIKELY
PROGRESS FROM MBS AT 00Z-01Z TO THE I-94 TERMINALS BY 03Z-05Z AND
THEN EXIT SOUTH OF WHOLE AREA AFTER 06-07Z. OTHERWISE THAN PATCHY
LATE NIGHT FOG TONIGHT...VFR CONDITIONS SHOULD...ONCE AGAIN...BE THE
RULE ONCE THE STORMY WEATHER ENDS TONIGHT.

FOR DTW...MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE
OF APPROACHING COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT.

&&

.PREV DISCUSSION...ISSUED 1153 AM EDT SUN AUG 2 2015

UPDATE...

FORECAST REMAINS IN GOOD SHAPE AS CONVECTIVE EVOLUTION TO OUR
NORTH HAS BEEN FAIRLY PREDICTABLE TO THIS POINT. SEVERAL CLUSTERS
OF STORMS CONTINUE TO PEEL EASTWARD ACROSS NORTHERN WISCONSIN ON
INTO THE UP AND NORTHERN LOWER MICHIGAN. THUNDERSTORM CHANCES WILL
INCREASE OVER THE NORTHERN CWA THIS AFTERNOON AS THE FLOW OF WARM
AND MOIST AIR PERSISTS AND A LARGE OUTFLOW BOUNDARY ALONG THE
SOUTHERN EDGE OF STORM COMPLEXES TO THE NORTH SETTLES INTO THE
FORECAST AREA AND PROVIDES FOCUS FOR THIS INCREASINGLY UNSTABLE
AIRMASS. WHILE AN ISOLATED STORM CANNOT BE RULED OUT AS FAR SOUTH
AS M 59 LATER THIS AFTERNOON...MOST ACTIVITY WILL REMAIN NORTH OF
THE I-69 CORRIDOR.

IT LOOKS INCREASINGLY LIKE THE NEXT ROUND OF THUNDERSTORMS WILL
ACTUALLY OVERLAP WITH THIS ONGOING ACTIVITY AS OPPOSED TO BEING A
MORE DISTINCT EPISODE. A CONTINUED FLOW OF MOIST/UNSTABLE AIR
ALONG THE AFOREMENTIONED OUTFLOW BOUNDARY SHOULD MAINTAIN FAIRLY
CONSISTENT CONVECTION ALONG/NORTH OF THE CWA INTO EARLY THIS
EVENING WITH ADDITIONAL DEVELOPING ACTIVITY ALONG APPROACHING
COLD FRONT THEN SPREADING INTO THE AREA FROM NORTHERN LOWER
MICHIGAN AND WISCONSON DURING THE COURSE OF THE EVENING...WHICH
WILL ACT TO DRAG EXISTING CONVECTION ALONG THE NORTHERN BORDER
SOUTHWARD INTO THE AREA.

NET RESULT WILL BE THE SAME AS STORM CHANCES INCREASE FROM NORTH
TO SOUTH ACROSS THE AREA FROM MID TO LATE EVENING. TIMING FOR
LARGEST THREAT OF STORMS FOR METRO DETROIT STILL APPEARS TO BE
MAINLY AFTER 10 PM AND PERHAPS CLOSER TO MIDNIGHT FOR MANY
LOCALES. WITH ANY LUCK...DECLINING INSTABILITY AT THIS LATER HOUR
WILL TAKE SOME PUNCH OUT OF THE LINE OF STORMS THAT EVENTUALLY
EVOLVES AND PROGRESSES INTO THE AREA LATER THIS EVENING. THAT
SAID...THE THREAT OF SEVERE WEATHER WILL PERSIST GIVEN THE STRONG
WIND FIELD AND AT LEAST A MODERATELY UNSTABLE AIRMASS AT THAT
POINT.

PREV DISCUSSION...ISSUED 526 AM EDT SUN AUG 2 2015

UPDATE...

A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH
RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM
EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS
AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST
REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE
THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS
ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF
M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING.

IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION
INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF
THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS
PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE
RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE
07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY
COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT
ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A
FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE
MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP
BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A
POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT
MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN
LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD
APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S
CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES
SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER
ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS
ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW
TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING
WORDING IN THE HWO AND OTHER PRODUCTS.

FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A
LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES
LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS
ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT
FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN
SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS
18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP
LAPSE RATE ENVIRONMENT.

PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

AVIATION.....DG
UPDATE.......DG
SHORT TERM...JVC
LONG TERM....SF
MARINE.......SF


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





000
FXUS63 KDTX 021746
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
146 PM EDT SUN AUG 2 2015


.AVIATION...

THUNDERSTORMS TO THE NORTH SHOULD CONGEAL AND DROP SOUTH THROUGH
AREA THIS EVENING AS A COLD FRONT DROPS SOUTH THROUGH THE CENTRAL
GREAT LAKES. EXPECT A DECENT CHANCE OF A POCKETS OF SEVERE WEATHER
WITHIN THIS EXPECTED AREA OF THUNDERSTORMS...WHICH WILL MOST LIKELY
PROGRESS FROM MBS AT 00Z-01Z TO THE I-94 TERMINALS BY 03Z-05Z AND
THEN EXIT SOUTH OF WHOLE AREA AFTER 06-07Z. OTHERWISE THAN PATCHY
LATE NIGHT FOG TONIGHT...VFR CONDITIONS SHOULD...ONCE AGAIN...BE THE
RULE ONCE THE STORMY WEATHER ENDS TONIGHT.

FOR DTW...MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE
OF APPROACHING COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT.

&&

.PREV DISCUSSION...ISSUED 1153 AM EDT SUN AUG 2 2015

UPDATE...

FORECAST REMAINS IN GOOD SHAPE AS CONVECTIVE EVOLUTION TO OUR
NORTH HAS BEEN FAIRLY PREDICTABLE TO THIS POINT. SEVERAL CLUSTERS
OF STORMS CONTINUE TO PEEL EASTWARD ACROSS NORTHERN WISCONSIN ON
INTO THE UP AND NORTHERN LOWER MICHIGAN. THUNDERSTORM CHANCES WILL
INCREASE OVER THE NORTHERN CWA THIS AFTERNOON AS THE FLOW OF WARM
AND MOIST AIR PERSISTS AND A LARGE OUTFLOW BOUNDARY ALONG THE
SOUTHERN EDGE OF STORM COMPLEXES TO THE NORTH SETTLES INTO THE
FORECAST AREA AND PROVIDES FOCUS FOR THIS INCREASINGLY UNSTABLE
AIRMASS. WHILE AN ISOLATED STORM CANNOT BE RULED OUT AS FAR SOUTH
AS M 59 LATER THIS AFTERNOON...MOST ACTIVITY WILL REMAIN NORTH OF
THE I-69 CORRIDOR.

IT LOOKS INCREASINGLY LIKE THE NEXT ROUND OF THUNDERSTORMS WILL
ACTUALLY OVERLAP WITH THIS ONGOING ACTIVITY AS OPPOSED TO BEING A
MORE DISTINCT EPISODE. A CONTINUED FLOW OF MOIST/UNSTABLE AIR
ALONG THE AFOREMENTIONED OUTFLOW BOUNDARY SHOULD MAINTAIN FAIRLY
CONSISTENT CONVECTION ALONG/NORTH OF THE CWA INTO EARLY THIS
EVENING WITH ADDITIONAL DEVELOPING ACTIVITY ALONG APPROACHING
COLD FRONT THEN SPREADING INTO THE AREA FROM NORTHERN LOWER
MICHIGAN AND WISCONSON DURING THE COURSE OF THE EVENING...WHICH
WILL ACT TO DRAG EXISTING CONVECTION ALONG THE NORTHERN BORDER
SOUTHWARD INTO THE AREA.

NET RESULT WILL BE THE SAME AS STORM CHANCES INCREASE FROM NORTH
TO SOUTH ACROSS THE AREA FROM MID TO LATE EVENING. TIMING FOR
LARGEST THREAT OF STORMS FOR METRO DETROIT STILL APPEARS TO BE
MAINLY AFTER 10 PM AND PERHAPS CLOSER TO MIDNIGHT FOR MANY
LOCALES. WITH ANY LUCK...DECLINING INSTABILITY AT THIS LATER HOUR
WILL TAKE SOME PUNCH OUT OF THE LINE OF STORMS THAT EVENTUALLY
EVOLVES AND PROGRESSES INTO THE AREA LATER THIS EVENING. THAT
SAID...THE THREAT OF SEVERE WEATHER WILL PERSIST GIVEN THE STRONG
WIND FIELD AND AT LEAST A MODERATELY UNSTABLE AIRMASS AT THAT
POINT.

PREV DISCUSSION...ISSUED 526 AM EDT SUN AUG 2 2015

UPDATE...

A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH
RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM
EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS
AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST
REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE
THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS
ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF
M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING.

IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION
INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF
THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS
PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE
RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE
07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY
COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT
ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A
FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE
MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP
BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A
POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT
MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN
LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD
APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S
CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES
SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER
ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS
ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW
TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING
WORDING IN THE HWO AND OTHER PRODUCTS.

FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A
LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES
LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS
ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT
FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN
SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS
18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP
LAPSE RATE ENVIRONMENT.

PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

AVIATION.....DG
UPDATE.......DG
SHORT TERM...JVC
LONG TERM....SF
MARINE.......SF


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




000
FXUS63 KDTX 021553
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1153 AM EDT SUN AUG 2 2015

.UPDATE...

FORECAST REMAINS IN GOOD SHAPE AS CONVECTIVE EVOLUTION TO OUR
NORTH HAS BEEN FAIRLY PREDICTABLE TO THIS POINT. SEVERAL CLUSTERS
OF STORMS CONTINUE TO PEEL EASTWARD ACROSS NORTHERN WISCONSIN ON
INTO THE UP AND NORTHERN LOWER MICHIGAN. THUNDERSTORM CHANCES WILL
INCREASE OVER THE NORTHERN CWA THIS AFTERNOON AS THE FLOW OF WARM
AND MOIST AIR PERSISTS AND A LARGE OUTFLOW BOUNDARY ALONG THE
SOUTHERN EDGE OF STORM COMPLEXES TO THE NORTH SETTLES INTO THE
FORECAST AREA AND PROVIDES FOCUS FOR THIS INCREASINGLY UNSTABLE
AIRMASS. WHILE AN ISOLATED STORM CANNOT BE RULED OUT AS FAR SOUTH
AS M 59 LATER THIS AFTERNOON...MOST ACTIVITY WILL REMAIN NORTH OF
THE I-69 CORRIDOR.

IT LOOKS INCREASINGLY LIKE THE NEXT ROUND OF THUNDERSTORMS WILL
ACTUALLY OVERLAP WITH THIS ONGOING ACTIVITY AS OPPOSED TO BEING A
MORE DISTINCT EPISODE. A CONTINUED FLOW OF MOIST/UNSTABLE AIR
ALONG THE AFOREMENTIONED OUTFLOW BOUNDARY SHOULD MAINTAIN FAIRLY
CONSISTENT CONVECTION ALONG/NORTH OF THE CWA INTO EARLY THIS
EVENING WITH ADDITIONAL DEVELOPING ACTIVITY ALONG APPROACHING
COLD FRONT THEN SPREADING INTO THE AREA FROM NORTHERN LOWER
MICHIGAN AND WISCONSON DURING THE COURSE OF THE EVENING...WHICH
WILL ACT TO DRAG EXISTING CONVECTION ALONG THE NORTHERN BORDER
SOUTHWARD INTO THE AREA.

NET RESULT WILL BE THE SAME AS STORM CHANCES INCREASE FROM NORTH
TO SOUTH ACROSS THE AREA FROM MID TO LATE EVENING. TIMING FOR
LARGEST THREAT OF STORMS FOR METRO DETROIT STILL APPEARS TO BE
MAINLY AFTER 10 PM AND PERHAPS CLOSER TO MIDNIGHT FOR MANY
LOCALES. WITH ANY LUCK...DECLINING INSTABILITY AT THIS LATER HOUR
WILL TAKE SOME PUNCH OUT OF THE LINE OF STORMS THAT EVENTUALLY
EVOLVES AND PROGRESSES INTO THE AREA LATER THIS EVENING. THAT
SAID...THE THREAT OF SEVERE WEATHER WILL PERSIST GIVEN THE STRONG
WIND FIELD AND AT LEAST A MODERATELY UNSTABLE AIRMASS AT THAT
POINT.

&&

.AVIATION...ISSUED 633 AM EDT SUN AUG 2 2015

STRENGTHENING SWLY WINDS WILL GUST TO AROUND 25 KTS LATE THIS
MORNING INTO AFTN IN ADVANCE OF AN APPROACHING TROUGH AND COLD
FRONT. INCREASING INSTABILITY WILL SUPPORT POTENTIAL FOR TSTORMS TO
IMPACT MAINLY KMBS/KFNT THIS AFTERNOON WHILE REMAINING TERMINALS
SHOULD REMAIN CAPPED WITH NOTHING MORE THAN HIGH BASED CU. MORE
SIGNIFICANT TSTORM EPISODE POSSIBLE 00Z-06Z TONIGHT AS UPSTREAM
CONVECTION ORGANIZES AND MOVES DOWNSTREAM CARRYING AN ELEVATED
SEVERE THREAT...PARTICULARLY FOR NW AREAS. UNCERTAINTY IS HIGHER IN
DETROIT AREA GIVEN EXPECTED TSTORM ARRIVAL WELL AFTER SUNSET AND
LOSS OF DIURNAL HEATING.

FOR DTW...VERY LOW CHANCE FOR A TSTORM INVOF KDTW 18-00Z WITH
CAPPING EXPECTED TO PREVAIL WARRANTING REMOVAL OF PRIOR PROB30
GROUP. MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE OF
THE COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT.

&&

.PREV DISCUSSION...ISSUED 526 AM EDT SUN AUG 2 2015

UPDATE...

A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH
RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM
EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS
AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST
REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE
THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS
ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF
M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING.

IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION
INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF
THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS
PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE
RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE
07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY
COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT
ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A
FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE
MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP
BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A
POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT
MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN
LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD
APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S
CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES
SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER
ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS
ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW
TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING
WORDING IN THE HWO AND OTHER PRODUCTS.

FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A
LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES
LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS
ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT
FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN
SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS
18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP
LAPSE RATE ENVIRONMENT.

&&

.PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

UPDATE.......DG
AVIATION.....JVC
SHORT TERM...JVC
LONG TERM....SF
MARINE.......SF


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




000
FXUS63 KDTX 021553
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1153 AM EDT SUN AUG 2 2015

.UPDATE...

FORECAST REMAINS IN GOOD SHAPE AS CONVECTIVE EVOLUTION TO OUR
NORTH HAS BEEN FAIRLY PREDICTABLE TO THIS POINT. SEVERAL CLUSTERS
OF STORMS CONTINUE TO PEEL EASTWARD ACROSS NORTHERN WISCONSIN ON
INTO THE UP AND NORTHERN LOWER MICHIGAN. THUNDERSTORM CHANCES WILL
INCREASE OVER THE NORTHERN CWA THIS AFTERNOON AS THE FLOW OF WARM
AND MOIST AIR PERSISTS AND A LARGE OUTFLOW BOUNDARY ALONG THE
SOUTHERN EDGE OF STORM COMPLEXES TO THE NORTH SETTLES INTO THE
FORECAST AREA AND PROVIDES FOCUS FOR THIS INCREASINGLY UNSTABLE
AIRMASS. WHILE AN ISOLATED STORM CANNOT BE RULED OUT AS FAR SOUTH
AS M 59 LATER THIS AFTERNOON...MOST ACTIVITY WILL REMAIN NORTH OF
THE I-69 CORRIDOR.

IT LOOKS INCREASINGLY LIKE THE NEXT ROUND OF THUNDERSTORMS WILL
ACTUALLY OVERLAP WITH THIS ONGOING ACTIVITY AS OPPOSED TO BEING A
MORE DISTINCT EPISODE. A CONTINUED FLOW OF MOIST/UNSTABLE AIR
ALONG THE AFOREMENTIONED OUTFLOW BOUNDARY SHOULD MAINTAIN FAIRLY
CONSISTENT CONVECTION ALONG/NORTH OF THE CWA INTO EARLY THIS
EVENING WITH ADDITIONAL DEVELOPING ACTIVITY ALONG APPROACHING
COLD FRONT THEN SPREADING INTO THE AREA FROM NORTHERN LOWER
MICHIGAN AND WISCONSON DURING THE COURSE OF THE EVENING...WHICH
WILL ACT TO DRAG EXISTING CONVECTION ALONG THE NORTHERN BORDER
SOUTHWARD INTO THE AREA.

NET RESULT WILL BE THE SAME AS STORM CHANCES INCREASE FROM NORTH
TO SOUTH ACROSS THE AREA FROM MID TO LATE EVENING. TIMING FOR
LARGEST THREAT OF STORMS FOR METRO DETROIT STILL APPEARS TO BE
MAINLY AFTER 10 PM AND PERHAPS CLOSER TO MIDNIGHT FOR MANY
LOCALES. WITH ANY LUCK...DECLINING INSTABILITY AT THIS LATER HOUR
WILL TAKE SOME PUNCH OUT OF THE LINE OF STORMS THAT EVENTUALLY
EVOLVES AND PROGRESSES INTO THE AREA LATER THIS EVENING. THAT
SAID...THE THREAT OF SEVERE WEATHER WILL PERSIST GIVEN THE STRONG
WIND FIELD AND AT LEAST A MODERATELY UNSTABLE AIRMASS AT THAT
POINT.

&&

.AVIATION...ISSUED 633 AM EDT SUN AUG 2 2015

STRENGTHENING SWLY WINDS WILL GUST TO AROUND 25 KTS LATE THIS
MORNING INTO AFTN IN ADVANCE OF AN APPROACHING TROUGH AND COLD
FRONT. INCREASING INSTABILITY WILL SUPPORT POTENTIAL FOR TSTORMS TO
IMPACT MAINLY KMBS/KFNT THIS AFTERNOON WHILE REMAINING TERMINALS
SHOULD REMAIN CAPPED WITH NOTHING MORE THAN HIGH BASED CU. MORE
SIGNIFICANT TSTORM EPISODE POSSIBLE 00Z-06Z TONIGHT AS UPSTREAM
CONVECTION ORGANIZES AND MOVES DOWNSTREAM CARRYING AN ELEVATED
SEVERE THREAT...PARTICULARLY FOR NW AREAS. UNCERTAINTY IS HIGHER IN
DETROIT AREA GIVEN EXPECTED TSTORM ARRIVAL WELL AFTER SUNSET AND
LOSS OF DIURNAL HEATING.

FOR DTW...VERY LOW CHANCE FOR A TSTORM INVOF KDTW 18-00Z WITH
CAPPING EXPECTED TO PREVAIL WARRANTING REMOVAL OF PRIOR PROB30
GROUP. MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE OF
THE COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT.

&&

.PREV DISCUSSION...ISSUED 526 AM EDT SUN AUG 2 2015

UPDATE...

A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH
RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM
EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS
AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST
REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE
THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS
ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF
M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING.

IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION
INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF
THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS
PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE
RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE
07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY
COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT
ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A
FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE
MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP
BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A
POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT
MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN
LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD
APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S
CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES
SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER
ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS
ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW
TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING
WORDING IN THE HWO AND OTHER PRODUCTS.

FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A
LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES
LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS
ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT
FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN
SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS
18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP
LAPSE RATE ENVIRONMENT.

&&

.PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

UPDATE.......DG
AVIATION.....JVC
SHORT TERM...JVC
LONG TERM....SF
MARINE.......SF


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





000
FXUS63 KDTX 021553
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1153 AM EDT SUN AUG 2 2015

.UPDATE...

FORECAST REMAINS IN GOOD SHAPE AS CONVECTIVE EVOLUTION TO OUR
NORTH HAS BEEN FAIRLY PREDICTABLE TO THIS POINT. SEVERAL CLUSTERS
OF STORMS CONTINUE TO PEEL EASTWARD ACROSS NORTHERN WISCONSIN ON
INTO THE UP AND NORTHERN LOWER MICHIGAN. THUNDERSTORM CHANCES WILL
INCREASE OVER THE NORTHERN CWA THIS AFTERNOON AS THE FLOW OF WARM
AND MOIST AIR PERSISTS AND A LARGE OUTFLOW BOUNDARY ALONG THE
SOUTHERN EDGE OF STORM COMPLEXES TO THE NORTH SETTLES INTO THE
FORECAST AREA AND PROVIDES FOCUS FOR THIS INCREASINGLY UNSTABLE
AIRMASS. WHILE AN ISOLATED STORM CANNOT BE RULED OUT AS FAR SOUTH
AS M 59 LATER THIS AFTERNOON...MOST ACTIVITY WILL REMAIN NORTH OF
THE I-69 CORRIDOR.

IT LOOKS INCREASINGLY LIKE THE NEXT ROUND OF THUNDERSTORMS WILL
ACTUALLY OVERLAP WITH THIS ONGOING ACTIVITY AS OPPOSED TO BEING A
MORE DISTINCT EPISODE. A CONTINUED FLOW OF MOIST/UNSTABLE AIR
ALONG THE AFOREMENTIONED OUTFLOW BOUNDARY SHOULD MAINTAIN FAIRLY
CONSISTENT CONVECTION ALONG/NORTH OF THE CWA INTO EARLY THIS
EVENING WITH ADDITIONAL DEVELOPING ACTIVITY ALONG APPROACHING
COLD FRONT THEN SPREADING INTO THE AREA FROM NORTHERN LOWER
MICHIGAN AND WISCONSON DURING THE COURSE OF THE EVENING...WHICH
WILL ACT TO DRAG EXISTING CONVECTION ALONG THE NORTHERN BORDER
SOUTHWARD INTO THE AREA.

NET RESULT WILL BE THE SAME AS STORM CHANCES INCREASE FROM NORTH
TO SOUTH ACROSS THE AREA FROM MID TO LATE EVENING. TIMING FOR
LARGEST THREAT OF STORMS FOR METRO DETROIT STILL APPEARS TO BE
MAINLY AFTER 10 PM AND PERHAPS CLOSER TO MIDNIGHT FOR MANY
LOCALES. WITH ANY LUCK...DECLINING INSTABILITY AT THIS LATER HOUR
WILL TAKE SOME PUNCH OUT OF THE LINE OF STORMS THAT EVENTUALLY
EVOLVES AND PROGRESSES INTO THE AREA LATER THIS EVENING. THAT
SAID...THE THREAT OF SEVERE WEATHER WILL PERSIST GIVEN THE STRONG
WIND FIELD AND AT LEAST A MODERATELY UNSTABLE AIRMASS AT THAT
POINT.

&&

.AVIATION...ISSUED 633 AM EDT SUN AUG 2 2015

STRENGTHENING SWLY WINDS WILL GUST TO AROUND 25 KTS LATE THIS
MORNING INTO AFTN IN ADVANCE OF AN APPROACHING TROUGH AND COLD
FRONT. INCREASING INSTABILITY WILL SUPPORT POTENTIAL FOR TSTORMS TO
IMPACT MAINLY KMBS/KFNT THIS AFTERNOON WHILE REMAINING TERMINALS
SHOULD REMAIN CAPPED WITH NOTHING MORE THAN HIGH BASED CU. MORE
SIGNIFICANT TSTORM EPISODE POSSIBLE 00Z-06Z TONIGHT AS UPSTREAM
CONVECTION ORGANIZES AND MOVES DOWNSTREAM CARRYING AN ELEVATED
SEVERE THREAT...PARTICULARLY FOR NW AREAS. UNCERTAINTY IS HIGHER IN
DETROIT AREA GIVEN EXPECTED TSTORM ARRIVAL WELL AFTER SUNSET AND
LOSS OF DIURNAL HEATING.

FOR DTW...VERY LOW CHANCE FOR A TSTORM INVOF KDTW 18-00Z WITH
CAPPING EXPECTED TO PREVAIL WARRANTING REMOVAL OF PRIOR PROB30
GROUP. MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE OF
THE COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT.

&&

.PREV DISCUSSION...ISSUED 526 AM EDT SUN AUG 2 2015

UPDATE...

A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH
RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM
EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS
AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST
REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE
THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS
ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF
M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING.

IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION
INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF
THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS
PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE
RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE
07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY
COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT
ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A
FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE
MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP
BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A
POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT
MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN
LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD
APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S
CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES
SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER
ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS
ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW
TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING
WORDING IN THE HWO AND OTHER PRODUCTS.

FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A
LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES
LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS
ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT
FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN
SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS
18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP
LAPSE RATE ENVIRONMENT.

&&

.PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

UPDATE.......DG
AVIATION.....JVC
SHORT TERM...JVC
LONG TERM....SF
MARINE.......SF


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




000
FXUS63 KDTX 021033
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
633 AM EDT SUN AUG 2 2015


.AVIATION...

STRENGTHENING SWLY WINDS WILL GUST TO AROUND 25 KTS LATE THIS
MORNING INTO AFTN IN ADVANCE OF AN APPROACHING TROUGH AND COLD
FRONT. INCREASING INSTABILITY WILL SUPPORT POTENTIAL FOR TSTORMS TO
IMPACT MAINLY KMBS/KFNT THIS AFTERNOON WHILE REMAINING TERMINALS
SHOULD REMAIN CAPPED WITH NOTHING MORE THAN HIGH BASED CU. MORE
SIGNIFICANT TSTORM EPISODE POSSIBLE 00Z-06Z TONIGHT AS UPSTREAM
CONVECTION ORGANIZES AND MOVES DOWNSTREAM CARRYING AN ELEVATED
SEVERE THREAT...PARTICULARLY FOR NW AREAS. UNCERTAINTY IS HIGHER IN
DETROIT AREA GIVEN EXPECTED TSTORM ARRIVAL WELL AFTER SUNSET AND
LOSS OF DIURNAL HEATING.

FOR DTW...VERY LOW CHANCE FOR A TSTORM INVOF KDTW 18-00Z WITH
CAPPING EXPECTED TO PREVAIL WARRANTING REMOVAL OF PRIOR PROB30
GROUP. MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE OF
THE COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT.

&&

.PREV DISCUSSION...ISSUED 526 AM EDT SUN AUG 2 2015

UPDATE...

A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH
RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM
EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS
AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST
REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE
THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS
ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF
M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING.

IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION
INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF
THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS
PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE
RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE
07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY
COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT
ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A
FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE
MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP
BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A
POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT
MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN
LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD
APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S
CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES
SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER
ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS
ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW
TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING
WORDING IN THE HWO AND OTHER PRODUCTS.

FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A
LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES
LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS
ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT
FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN
SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS
18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP
LAPSE RATE ENVIRONMENT.

PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM NOON EDT TODAY THROUGH THIS EVENING
     FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LEZ444.

&&

$$

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


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





000
FXUS63 KDTX 021033
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
633 AM EDT SUN AUG 2 2015


.AVIATION...

STRENGTHENING SWLY WINDS WILL GUST TO AROUND 25 KTS LATE THIS
MORNING INTO AFTN IN ADVANCE OF AN APPROACHING TROUGH AND COLD
FRONT. INCREASING INSTABILITY WILL SUPPORT POTENTIAL FOR TSTORMS TO
IMPACT MAINLY KMBS/KFNT THIS AFTERNOON WHILE REMAINING TERMINALS
SHOULD REMAIN CAPPED WITH NOTHING MORE THAN HIGH BASED CU. MORE
SIGNIFICANT TSTORM EPISODE POSSIBLE 00Z-06Z TONIGHT AS UPSTREAM
CONVECTION ORGANIZES AND MOVES DOWNSTREAM CARRYING AN ELEVATED
SEVERE THREAT...PARTICULARLY FOR NW AREAS. UNCERTAINTY IS HIGHER IN
DETROIT AREA GIVEN EXPECTED TSTORM ARRIVAL WELL AFTER SUNSET AND
LOSS OF DIURNAL HEATING.

FOR DTW...VERY LOW CHANCE FOR A TSTORM INVOF KDTW 18-00Z WITH
CAPPING EXPECTED TO PREVAIL WARRANTING REMOVAL OF PRIOR PROB30
GROUP. MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE OF
THE COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT.

&&

.PREV DISCUSSION...ISSUED 526 AM EDT SUN AUG 2 2015

UPDATE...

A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH
RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM
EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS
AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST
REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE
THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS
ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF
M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING.

IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION
INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF
THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS
PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE
RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE
07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY
COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT
ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A
FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE
MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP
BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A
POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT
MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN
LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD
APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S
CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES
SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER
ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS
ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW
TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING
WORDING IN THE HWO AND OTHER PRODUCTS.

FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A
LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES
LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS
ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT
FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN
SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS
18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP
LAPSE RATE ENVIRONMENT.

PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM NOON EDT TODAY THROUGH THIS EVENING
     FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LEZ444.

&&

$$

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


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




000
FXUS63 KDTX 020926
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
526 AM EDT SUN AUG 2 2015

.UPDATE...

A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH
RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM
EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS
AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST
REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE
THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS
ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF
M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING.

IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION
INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF
THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS
PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE
RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE
07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY
COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT
ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A
FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE
MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP
BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A
POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT
MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN
LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD
APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S
CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES
SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER
ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS
ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW
TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING
WORDING IN THE HWO AND OTHER PRODUCTS.

FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A
LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES
LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS
ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT
FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN
SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS
18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP
LAPSE RATE ENVIRONMENT.

&&

.PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.AVIATION...ISSUED 1147 PM EDT SAT AUG 1 2015

SW WINDS WILL INCREASE LATE SUN MORNING INTO SUN AFTERNOON DUE BOTH
TO DIURNAL MIXING AND A STRENGTHENING WSW GRADIENT IN ADVANCE OF AN
APPROACHING COLD FRONT. AN INFLUX OF INSTABILITY DURING THE DAY WILL
LEAD TO INCREASING CHANCES FOR THUNDERSTORMS...TIMING OF WHICH
CARRIES A GOOD DEAL OF UNCERTAINTY AT THIS EARLY STAGE IN THE
FORECAST.

FOR DTW...THE TWO MOST PROBABLE TIME PERIOD FOR THUNDERSTORM
IMPACTING METRO WILL BE SUN AFTERNOON WITH THE INFLUX OF INSTABILITY
AND LATE SUN EVENING/NIGHT AHEAD OF A COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN THUNDERSTORMS SUNDAY AFTERNOON AND NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM NOON EDT TODAY THROUGH THIS EVENING
     FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LEZ444.

&&

$$

UPDATE.......JVC
AVIATION.....SC
SHORT TERM...JVC
LONG TERM....SF
MARINE.......SF


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




000
FXUS63 KDTX 020926
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
526 AM EDT SUN AUG 2 2015

.UPDATE...

A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH
RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM
EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS
AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST
REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE
THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS
ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF
M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING.

IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION
INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF
THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS
PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE
RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE
07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY
COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT
ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A
FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE
MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP
BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A
POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT
MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN
LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD
APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S
CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES
SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER
ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS
ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW
TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING
WORDING IN THE HWO AND OTHER PRODUCTS.

FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A
LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES
LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS
ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT
FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN
SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS
18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP
LAPSE RATE ENVIRONMENT.

&&

.PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015

SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.AVIATION...ISSUED 1147 PM EDT SAT AUG 1 2015

SW WINDS WILL INCREASE LATE SUN MORNING INTO SUN AFTERNOON DUE BOTH
TO DIURNAL MIXING AND A STRENGTHENING WSW GRADIENT IN ADVANCE OF AN
APPROACHING COLD FRONT. AN INFLUX OF INSTABILITY DURING THE DAY WILL
LEAD TO INCREASING CHANCES FOR THUNDERSTORMS...TIMING OF WHICH
CARRIES A GOOD DEAL OF UNCERTAINTY AT THIS EARLY STAGE IN THE
FORECAST.

FOR DTW...THE TWO MOST PROBABLE TIME PERIOD FOR THUNDERSTORM
IMPACTING METRO WILL BE SUN AFTERNOON WITH THE INFLUX OF INSTABILITY
AND LATE SUN EVENING/NIGHT AHEAD OF A COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN THUNDERSTORMS SUNDAY AFTERNOON AND NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM NOON EDT TODAY THROUGH THIS EVENING
     FOR MIZ049.

LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LEZ444.

&&

$$

UPDATE.......JVC
AVIATION.....SC
SHORT TERM...JVC
LONG TERM....SF
MARINE.......SF


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




000
FXUS63 KDTX 020652
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
252 AM EDT SUN AUG 2 2015

.SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

&&

.LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

&&

.MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.AVIATION...ISSUED 1147 PM EDT SAT AUG 1 2015

SW WINDS WILL INCREASE LATE SUN MORNING INTO SUN AFTERNOON DUE BOTH
TO DIURNAL MIXING AND A STRENGTHENING WSW GRADIENT IN ADVANCE OF AN
APPROACHING COLD FRONT. AN INFLUX OF INSTABILITY DURING THE DAY WILL
LEAD TO INCREASING CHANCES FOR THUNDERSTORMS...TIMING OF WHICH
CARRIES A GOOD DEAL OF UNCERTAINTY AT THIS EARLY STAGE IN THE
FORECAST.

FOR DTW...THE TWO MOST PROBABLE TIME PERIOD FOR THUNDERSTORM
IMPACTING METRO WILL BE SUN AFTERNOON WITH THE INFLUX OF INSTABILITY
AND LATE SUN EVENING/NIGHT AHEAD OF A COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN THUNDERSTORMS SUNDAY AFTERNOON AND NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LEZ444.

&&

$$

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


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




000
FXUS63 KDTX 020652
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
252 AM EDT SUN AUG 2 2015

.SHORT TERM...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE
PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING
WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD
CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE
AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS
LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE
CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85
TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS
APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING
ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW
VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS
ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF
THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE
STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND
UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE
A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED
SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO
GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED
AREAS.

SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT,
LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND
QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF
PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA
OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z.
BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT
LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND
THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING
EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE
INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND
PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR
AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM
MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD
THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF
INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION.

&&

.LONG TERM...

UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW
CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE
CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN
SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER
12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY
FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL
LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP
ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS
ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM
NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS
STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80
DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY
TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S.
A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH
NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME
INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE
UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS
TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING
HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING
NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID
50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY.

&&

.MARINE...

SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD
FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE
WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT
ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE
SEVERE...PRODUCING WINDS OF 50 KNOTS.  WINDS WILL TURN WEST AND THEN
NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO
BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN
15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR
SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE
OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS
TIME FRAME AS WELL.

&&

.AVIATION...ISSUED 1147 PM EDT SAT AUG 1 2015

SW WINDS WILL INCREASE LATE SUN MORNING INTO SUN AFTERNOON DUE BOTH
TO DIURNAL MIXING AND A STRENGTHENING WSW GRADIENT IN ADVANCE OF AN
APPROACHING COLD FRONT. AN INFLUX OF INSTABILITY DURING THE DAY WILL
LEAD TO INCREASING CHANCES FOR THUNDERSTORMS...TIMING OF WHICH
CARRIES A GOOD DEAL OF UNCERTAINTY AT THIS EARLY STAGE IN THE
FORECAST.

FOR DTW...THE TWO MOST PROBABLE TIME PERIOD FOR THUNDERSTORM
IMPACTING METRO WILL BE SUN AFTERNOON WITH THE INFLUX OF INSTABILITY
AND LATE SUN EVENING/NIGHT AHEAD OF A COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN THUNDERSTORMS SUNDAY AFTERNOON AND NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR
     LEZ444.

&&

$$

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


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





000
FXUS63 KDTX 020347
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1147 PM EDT SAT AUG 1 2015


.AVIATION...

SW WINDS WILL INCREASE LATE SUN MORNING INTO SUN AFTERNOON DUE BOTH
TO DIURNAL MIXING AND A STRENGTHENING WSW GRADIENT IN ADVANCE OF AN
APPROACHING COLD FRONT. AN INFLUX OF INSTABILITY DURING THE DAY WILL
LEAD TO INCREASING CHANCES FOR THUNDERSTORMS...TIMING OF WHICH
CARRIES A GOOD DEAL OF UNCERTAINTY AT THIS EARLY STAGE IN THE
FORECAST.

FOR DTW...THE TWO MOST PROBABLE TIME PERIOD FOR THUNDERSTORM
IMPACTING METRO WILL BE SUN AFTERNOON WITH THE INFLUX OF INSTABILITY
AND LATE SUN EVENING/NIGHT AHEAD OF A COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN THUNDERSTORMS SUNDAY AFTERNOON AND NIGHT.

&&

.PREV DISCUSSION...ISSUED 353 PM EDT SAT AUG 1 2015

SHORT TERM...THIS AFTERNOON AND TONIGHT

ISOLATED TO WIDELY SCATTERED SHOWERS HAVE WORKED OUT AS EXPECTED
THIS AFTERNOON AS WEAK SHORTWAVE SKIRTS THE AREA TO THE NORTH AND
NORTHEAST. SLIGHTLY BETTER LOW LEVEL CONVERGENCE HAS FOCUSED FROM
NEAR THE SAGINAW VALLEY ESE INTO THE THUMB AND ACTIVITY HAS TO THIS
POINT REMAINS CONFINED TO THIS PORTION OF THE CWA. ANY STRAY LIGHT
SHOWERS OR SPRINKLES TO THE SW OF THIS MAIN AREA WILL BE TRIVIAL AND
ALL ACTIVITY WILL FADE RATHER QUICKLY FROM LATE AFTERNOON INTO EARLY
EVENING AS BOTH LIFT FROM SHORTWAVE AND MINOR INSTABILITY FROM DAY
TIME HEATING ARE LOST.

WITH MOSTLY CLEAR SKIES OVERNIGHT TONIGHT...EXPECT DECENT RADIATIONAL
COOLING AS SW WINDS DECREASE TO AROUND 5 MPH AND SURFACE DEW POINTS
SETTLE INTO THE 50 TO 55F RANGE. THIS WILL PRODUCE A PLEASANT NIGHT
WITH LOW TEMPERATURES IN THE UPPER 50S TO LOWER 60S. THESE LOWS MAY
OCCUR A FEW HOURS EARLIER THAN USUAL AS THE LOW LEVEL GRADIENT DOES
BEGIN TO TIGHTEN IN THE 09Z-12Z TIME FRAME...WHICH WILL LEAD TO WIND
SPEEDS INCREASING TO SOME EXTENT FAIRLY EARLY IN THE MORNING.

LONG TERM...

THE UPPER SHORTWAVE NOW OVER NORTHERN SASKATCHEWAN AND MANITOBA WILL
DROP DOWN INTO THE GREAT LAKES SUNDAY AND SUNDAY NIGHT AS THE UPPER
LOW OVER HUDSON BAY SINKS SOUTHWARD. A STREAM OF SMALLER SHORTWAVES
ALIGNED ALONG A JET AXIS STRETCHING BACK THROUGH WESTERN AND CENTRAL
CANADA WILL ALSO FEED INTO AND POTENTIALLY STRENGTHEN THIS WAVE AS
IT DROPS INTO THE AREA TOMORROW. AT THE SURFACE...A TROUGH WILL
SWING ACROSS MICHIGAN LATE SUNDAY THROUGH SUNDAY NIGHT. MODELS
CONTINUE TO SHOW A FAVORABLE ENVIRONMENT FOR THIS TROUGH TO DEEPEN
OR EVEN CLOSE OFF BY SUNDAY NIGHT...AS IT BECOMES CENTERED UNDER
UPPER HEIGHT FALLS AND MORE FAVORABLE RIGHT ENTRANCE FORCING OF THE
UPPER JET.

IN ADVANCE OF THE TROUGH...PLUME OF HIGHER MOISTURE CAN ALREADY BE
SEEN ON WATER VAPOR IMAGERY COMING IN OFF THE PACIFIC AND STREAMING
WELL INTO CANADA. MODELS ARE IN GOOD AGREEMENT WITH THIS MOISTURE
GETTING SCOOPED UP BY THE SYSTEM...AND POOLING AHEAD OF A COLD FRONT
THAT WILL DROP THROUGH SOUTHEAST MICHIGAN DURING LATE EVENING AND
OVERNIGHT SUNDAY. LATEST RUNS SHOW PW VALUES IN THE 1.0 TO 1.5 INCH
RANGE...EVEN SLIGHTLY HIGHER.

POTENTIAL EXISTS FOR A FEW ROUNDS OF THUNDERSTORMS SUNDAY AND SUNDAY
NIGHT. THE FIRST ROUND WILL BE POSSIBLE DURING THE MORNING AND
THROUGH THE EARLY AFTERNOON AS AN UPPER SHORTWAVE OVER MONTANA FIRST
TRACKS THROUGH THE AREA...COINCIDENT WITH A WEAK WARM FRONT AND
INITIAL THETA-E ADVECTION ALSO LIFTING THROUGH THE AREA IN ADVANCE OF
THE APPROACHING TROUGH. FORECAST SOUNDINGS SHOW INSTABILITY WILL BE
ELEVATED FOR THIS ROUND (IF IT OCCURS)...AND WITH THE BETTER CORE OF
WINDS STILL UPSTREAM...THIS SHOULD LIMIT SEVERE POTENTIAL FOR THE
FIRST PART OF THE DAY. THOUGHT IS THAT WE WILL THEN SEE A BREAK IN
ACTIVITY MID-DAY UNDER SUBSIDENCE BEHIND THE UPPER WAVE AND WHILE
INSTABILITY RECOVERS FROM EARLY CONVECTION/CLOUDS.

STRONG LOW-LEVEL JET (50-60 KNOTS) SHOULD SURGE INTO THE AREA DURING
THE LATER PART OF THE AFTERNOON INTO THE EARLY OVERNIGHT HOURS. THIS
SHOULD PROVIDE ADDITIONAL INSTABILITY AND MOISTURE...AND ALLOW 0-6KM
BULK SHEAR VALUES TO INCREASE TO 30-40 KNOTS BY EVENING. STILL SOME
UNCERTAINTY AS TO WHETHER THE WARMER AIR ALOFT WILL BE TOO MUCH AND
KEEP A CAP OVER THE AREA...MODEL FORECAST SOUNDINGS ARE STILL
DIVIDED ON THIS BUT MAY ALSO BE EXHIBITING SOME CONVECTIVE FEEDBACK.
BETTER PUSH OF MOISTURE IN THE EVENING SHOULD ALIGN NICELY WITH
FORCING HOWEVER (FRONT..STRONG FGEN...MID-LEVEL PVA...RIGHT ENTRANCE
REGION) FOR SHOWERS AND THUNDERSTORMS TO BECOME LIKELY. MAIN
QUESTION WILL BE STRENGTH AND IF WE CAN GET A MORE ORGANIZED
CONVECTIVE SYSTEM GOING. PRELIMINARY THOUGHTS FOR THE EVENING ARE TO
SEE A LINE OF STORMS DEVELOP ALONG THE COLD FRONT UPSTREAM OVER
NORTHERN MICHIGAN AND WISCONSIN DURING THE EVENING (STILL SOME
TIMING DIFFERENCES IN MODELS HOWEVER THAT HAVE TO BE WATCHED)
.WITH THIS LINE THEN MOVING ACROSS SOUTHEAST MICHIGAN DURING THE
LATER PART OF THE EVENING AND OVERNIGHT HOURS. WILL HAVE TO WATCH
POTENTIAL FOR AN MCS TO DEVELOP OVER THE AREA...GIVEN STRONG INFLOW
FROM THE LOW-LEVEL JET AND STRONG UPPER DIVERGENCE OVER THE REGION.
MODELS CONTINUE TO SHOW BETWEEN 1000-2000 J/KG OF CAPE DURING THE
EVENING/OVERNIGHT AS THE FRONT DROPS THROUGH. COMBINED WITH SHEAR
VALUES...THIS WILL SUPPORT A THREAT FOR SEVERE STORMS. PRIMARY
THREATS WILL BE DAMAGING WINDS AND LARGE HAIL...BUT CANNOT RULE OUT
TORNADO THREAT WITH LCL HEIGHTS DROPPING OVERNIGHT WHILE 0-1KM SHEAR
INCREASE. VERY HEAVY RAINFALL CAN ALSO BE EXPECTED...BUT FAST
MOVEMENT OF STORMS SHOULD KEEP FLOOD POTENTIAL LOCALIZED.

TUESDAY THROUGH SATURDAY. BREEZY WEST TO NORTHWEST WINDS WILL
ACCOMPANY THE LINGERING SURFACE TROUGH TUESDAY AFTERNOON. THE MINOR
INSTABILITY INDUCED BY THE TROUGH AND AFTERNOON SURFACE HEATING
COULD TRIGGER SOME SCATTERED SHOWERS AND A POSSIBLE RUMBLE OR TWO
.ESPECIALLY OVER THE NORTHERN THUMB AREAS. MODELS INDICATE LITTLE
ENERGY LEFTOVER TO SUPPORT MORE THAN ISOLATED GARDEN VARIETY
THUNDERSTORMS. WEDNESDAY AND THURSDAY STILL LOOK FAVORABLE FOR AMPLE
SUN AMID DRIER/COOLER CONDITIONS. CLOUDS BEGIN INCREASING THURSDAY
EVENING AHEAD OF FRIDAY`S WEATHER SYSTEM...WHICH IS TOO FAR OUT TO
PUT ANY FAITH IN TIMING OR IMPACT. AFTERNOON HIGH TEMPERATURES
HITTING BELOW AVERAGE ALL WEEK WITH 70S PERSISTING THROUGH SATURDAY.

MARINE...

WESTERLY WINDS WILL CONTINUE TO GUST TO AROUND 20 KNOTS INTO THIS
EVENING OVER LAKE ST CLAIR AND WESTERN LAKE ERIE IN RESPONSE TO A
WEAK TROUGH MOVING THROUGH THE CENTRAL GREAT LAKES. A FEW
THUNDERSTORMS WILL ALSO BE POSSIBLE OVER LAKE HURON THIS
EVENING...BEFORE ACTIVITY DISSIPATES.

WINDS WILL BECOME LIGHT OVERNIGHT BEFORE INCREASING FROM THE
SOUTHWEST BY LATE SUNDAY MORNING AS A DEEPENING TROUGH OF LOW
PRESSURE MOVES TOWARDS THE AREA. WINDS ARE EXPECTED TO GUST TO
AROUND 25 KNOTS FOR MOST NEARSHORE AREAS...BUT ATTAIN SLIGHTLY
HIGHER SPEEDS...UP TO 30 KNOTS...OVER SAGINAW BAY WHERE SOUTHWEST
WINDS WILL FUNNEL. WINDS WILL BEGIN TO DIMINISH LATE SUNDAY NIGHT AS
THE TROUGH MOVES OVERHEAD. SMALL CRAFT ADVISORIES ARE NOW IN EFFECT
FOR ALL NEARSHORE AREAS FROM LATE SUNDAY MORNING THROUGH LATE MONDAY
NIGHT. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND A COLD FRONT
EARLY ON MONDAY. SPEEDS MONDAY LOOK TO BE GREATEST OVER LAKE
HURON...WHERE THEY WILL REACH 15 TO 20 KNOTS FROM THE NORTHWEST. IN
ADDITION...THUNDERSTORMS WILL BE POSSIBLE SUNDAY AND SUNDAY NIGHT.
SOME OF THESE STORMS MAY BECOME SEVERE...WITH DAMAGING WIND GUSTS TO
50 KNOTS THE MAIN THREAT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM SUNDAY TO 4 AM EDT MONDAY FOR
     LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM SUNDAY TO 4 AM EDT MONDAY FOR
     LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM SUNDAY TO 4 AM EDT MONDAY FOR
     LEZ444.

&&

$$

AVIATION.....SC
SHORT TERM...DG
LONG TERM....HLO/DE
MARINE.......HLO


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




000
FXUS63 KDTX 020347
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1147 PM EDT SAT AUG 1 2015


.AVIATION...

SW WINDS WILL INCREASE LATE SUN MORNING INTO SUN AFTERNOON DUE BOTH
TO DIURNAL MIXING AND A STRENGTHENING WSW GRADIENT IN ADVANCE OF AN
APPROACHING COLD FRONT. AN INFLUX OF INSTABILITY DURING THE DAY WILL
LEAD TO INCREASING CHANCES FOR THUNDERSTORMS...TIMING OF WHICH
CARRIES A GOOD DEAL OF UNCERTAINTY AT THIS EARLY STAGE IN THE
FORECAST.

FOR DTW...THE TWO MOST PROBABLE TIME PERIOD FOR THUNDERSTORM
IMPACTING METRO WILL BE SUN AFTERNOON WITH THE INFLUX OF INSTABILITY
AND LATE SUN EVENING/NIGHT AHEAD OF A COLD FRONT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN THUNDERSTORMS SUNDAY AFTERNOON AND NIGHT.

&&

.PREV DISCUSSION...ISSUED 353 PM EDT SAT AUG 1 2015

SHORT TERM...THIS AFTERNOON AND TONIGHT

ISOLATED TO WIDELY SCATTERED SHOWERS HAVE WORKED OUT AS EXPECTED
THIS AFTERNOON AS WEAK SHORTWAVE SKIRTS THE AREA TO THE NORTH AND
NORTHEAST. SLIGHTLY BETTER LOW LEVEL CONVERGENCE HAS FOCUSED FROM
NEAR THE SAGINAW VALLEY ESE INTO THE THUMB AND ACTIVITY HAS TO THIS
POINT REMAINS CONFINED TO THIS PORTION OF THE CWA. ANY STRAY LIGHT
SHOWERS OR SPRINKLES TO THE SW OF THIS MAIN AREA WILL BE TRIVIAL AND
ALL ACTIVITY WILL FADE RATHER QUICKLY FROM LATE AFTERNOON INTO EARLY
EVENING AS BOTH LIFT FROM SHORTWAVE AND MINOR INSTABILITY FROM DAY
TIME HEATING ARE LOST.

WITH MOSTLY CLEAR SKIES OVERNIGHT TONIGHT...EXPECT DECENT RADIATIONAL
COOLING AS SW WINDS DECREASE TO AROUND 5 MPH AND SURFACE DEW POINTS
SETTLE INTO THE 50 TO 55F RANGE. THIS WILL PRODUCE A PLEASANT NIGHT
WITH LOW TEMPERATURES IN THE UPPER 50S TO LOWER 60S. THESE LOWS MAY
OCCUR A FEW HOURS EARLIER THAN USUAL AS THE LOW LEVEL GRADIENT DOES
BEGIN TO TIGHTEN IN THE 09Z-12Z TIME FRAME...WHICH WILL LEAD TO WIND
SPEEDS INCREASING TO SOME EXTENT FAIRLY EARLY IN THE MORNING.

LONG TERM...

THE UPPER SHORTWAVE NOW OVER NORTHERN SASKATCHEWAN AND MANITOBA WILL
DROP DOWN INTO THE GREAT LAKES SUNDAY AND SUNDAY NIGHT AS THE UPPER
LOW OVER HUDSON BAY SINKS SOUTHWARD. A STREAM OF SMALLER SHORTWAVES
ALIGNED ALONG A JET AXIS STRETCHING BACK THROUGH WESTERN AND CENTRAL
CANADA WILL ALSO FEED INTO AND POTENTIALLY STRENGTHEN THIS WAVE AS
IT DROPS INTO THE AREA TOMORROW. AT THE SURFACE...A TROUGH WILL
SWING ACROSS MICHIGAN LATE SUNDAY THROUGH SUNDAY NIGHT. MODELS
CONTINUE TO SHOW A FAVORABLE ENVIRONMENT FOR THIS TROUGH TO DEEPEN
OR EVEN CLOSE OFF BY SUNDAY NIGHT...AS IT BECOMES CENTERED UNDER
UPPER HEIGHT FALLS AND MORE FAVORABLE RIGHT ENTRANCE FORCING OF THE
UPPER JET.

IN ADVANCE OF THE TROUGH...PLUME OF HIGHER MOISTURE CAN ALREADY BE
SEEN ON WATER VAPOR IMAGERY COMING IN OFF THE PACIFIC AND STREAMING
WELL INTO CANADA. MODELS ARE IN GOOD AGREEMENT WITH THIS MOISTURE
GETTING SCOOPED UP BY THE SYSTEM...AND POOLING AHEAD OF A COLD FRONT
THAT WILL DROP THROUGH SOUTHEAST MICHIGAN DURING LATE EVENING AND
OVERNIGHT SUNDAY. LATEST RUNS SHOW PW VALUES IN THE 1.0 TO 1.5 INCH
RANGE...EVEN SLIGHTLY HIGHER.

POTENTIAL EXISTS FOR A FEW ROUNDS OF THUNDERSTORMS SUNDAY AND SUNDAY
NIGHT. THE FIRST ROUND WILL BE POSSIBLE DURING THE MORNING AND
THROUGH THE EARLY AFTERNOON AS AN UPPER SHORTWAVE OVER MONTANA FIRST
TRACKS THROUGH THE AREA...COINCIDENT WITH A WEAK WARM FRONT AND
INITIAL THETA-E ADVECTION ALSO LIFTING THROUGH THE AREA IN ADVANCE OF
THE APPROACHING TROUGH. FORECAST SOUNDINGS SHOW INSTABILITY WILL BE
ELEVATED FOR THIS ROUND (IF IT OCCURS)...AND WITH THE BETTER CORE OF
WINDS STILL UPSTREAM...THIS SHOULD LIMIT SEVERE POTENTIAL FOR THE
FIRST PART OF THE DAY. THOUGHT IS THAT WE WILL THEN SEE A BREAK IN
ACTIVITY MID-DAY UNDER SUBSIDENCE BEHIND THE UPPER WAVE AND WHILE
INSTABILITY RECOVERS FROM EARLY CONVECTION/CLOUDS.

STRONG LOW-LEVEL JET (50-60 KNOTS) SHOULD SURGE INTO THE AREA DURING
THE LATER PART OF THE AFTERNOON INTO THE EARLY OVERNIGHT HOURS. THIS
SHOULD PROVIDE ADDITIONAL INSTABILITY AND MOISTURE...AND ALLOW 0-6KM
BULK SHEAR VALUES TO INCREASE TO 30-40 KNOTS BY EVENING. STILL SOME
UNCERTAINTY AS TO WHETHER THE WARMER AIR ALOFT WILL BE TOO MUCH AND
KEEP A CAP OVER THE AREA...MODEL FORECAST SOUNDINGS ARE STILL
DIVIDED ON THIS BUT MAY ALSO BE EXHIBITING SOME CONVECTIVE FEEDBACK.
BETTER PUSH OF MOISTURE IN THE EVENING SHOULD ALIGN NICELY WITH
FORCING HOWEVER (FRONT..STRONG FGEN...MID-LEVEL PVA...RIGHT ENTRANCE
REGION) FOR SHOWERS AND THUNDERSTORMS TO BECOME LIKELY. MAIN
QUESTION WILL BE STRENGTH AND IF WE CAN GET A MORE ORGANIZED
CONVECTIVE SYSTEM GOING. PRELIMINARY THOUGHTS FOR THE EVENING ARE TO
SEE A LINE OF STORMS DEVELOP ALONG THE COLD FRONT UPSTREAM OVER
NORTHERN MICHIGAN AND WISCONSIN DURING THE EVENING (STILL SOME
TIMING DIFFERENCES IN MODELS HOWEVER THAT HAVE TO BE WATCHED)
.WITH THIS LINE THEN MOVING ACROSS SOUTHEAST MICHIGAN DURING THE
LATER PART OF THE EVENING AND OVERNIGHT HOURS. WILL HAVE TO WATCH
POTENTIAL FOR AN MCS TO DEVELOP OVER THE AREA...GIVEN STRONG INFLOW
FROM THE LOW-LEVEL JET AND STRONG UPPER DIVERGENCE OVER THE REGION.
MODELS CONTINUE TO SHOW BETWEEN 1000-2000 J/KG OF CAPE DURING THE
EVENING/OVERNIGHT AS THE FRONT DROPS THROUGH. COMBINED WITH SHEAR
VALUES...THIS WILL SUPPORT A THREAT FOR SEVERE STORMS. PRIMARY
THREATS WILL BE DAMAGING WINDS AND LARGE HAIL...BUT CANNOT RULE OUT
TORNADO THREAT WITH LCL HEIGHTS DROPPING OVERNIGHT WHILE 0-1KM SHEAR
INCREASE. VERY HEAVY RAINFALL CAN ALSO BE EXPECTED...BUT FAST
MOVEMENT OF STORMS SHOULD KEEP FLOOD POTENTIAL LOCALIZED.

TUESDAY THROUGH SATURDAY. BREEZY WEST TO NORTHWEST WINDS WILL
ACCOMPANY THE LINGERING SURFACE TROUGH TUESDAY AFTERNOON. THE MINOR
INSTABILITY INDUCED BY THE TROUGH AND AFTERNOON SURFACE HEATING
COULD TRIGGER SOME SCATTERED SHOWERS AND A POSSIBLE RUMBLE OR TWO
.ESPECIALLY OVER THE NORTHERN THUMB AREAS. MODELS INDICATE LITTLE
ENERGY LEFTOVER TO SUPPORT MORE THAN ISOLATED GARDEN VARIETY
THUNDERSTORMS. WEDNESDAY AND THURSDAY STILL LOOK FAVORABLE FOR AMPLE
SUN AMID DRIER/COOLER CONDITIONS. CLOUDS BEGIN INCREASING THURSDAY
EVENING AHEAD OF FRIDAY`S WEATHER SYSTEM...WHICH IS TOO FAR OUT TO
PUT ANY FAITH IN TIMING OR IMPACT. AFTERNOON HIGH TEMPERATURES
HITTING BELOW AVERAGE ALL WEEK WITH 70S PERSISTING THROUGH SATURDAY.

MARINE...

WESTERLY WINDS WILL CONTINUE TO GUST TO AROUND 20 KNOTS INTO THIS
EVENING OVER LAKE ST CLAIR AND WESTERN LAKE ERIE IN RESPONSE TO A
WEAK TROUGH MOVING THROUGH THE CENTRAL GREAT LAKES. A FEW
THUNDERSTORMS WILL ALSO BE POSSIBLE OVER LAKE HURON THIS
EVENING...BEFORE ACTIVITY DISSIPATES.

WINDS WILL BECOME LIGHT OVERNIGHT BEFORE INCREASING FROM THE
SOUTHWEST BY LATE SUNDAY MORNING AS A DEEPENING TROUGH OF LOW
PRESSURE MOVES TOWARDS THE AREA. WINDS ARE EXPECTED TO GUST TO
AROUND 25 KNOTS FOR MOST NEARSHORE AREAS...BUT ATTAIN SLIGHTLY
HIGHER SPEEDS...UP TO 30 KNOTS...OVER SAGINAW BAY WHERE SOUTHWEST
WINDS WILL FUNNEL. WINDS WILL BEGIN TO DIMINISH LATE SUNDAY NIGHT AS
THE TROUGH MOVES OVERHEAD. SMALL CRAFT ADVISORIES ARE NOW IN EFFECT
FOR ALL NEARSHORE AREAS FROM LATE SUNDAY MORNING THROUGH LATE MONDAY
NIGHT. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND A COLD FRONT
EARLY ON MONDAY. SPEEDS MONDAY LOOK TO BE GREATEST OVER LAKE
HURON...WHERE THEY WILL REACH 15 TO 20 KNOTS FROM THE NORTHWEST. IN
ADDITION...THUNDERSTORMS WILL BE POSSIBLE SUNDAY AND SUNDAY NIGHT.
SOME OF THESE STORMS MAY BECOME SEVERE...WITH DAMAGING WIND GUSTS TO
50 KNOTS THE MAIN THREAT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM SUNDAY TO 4 AM EDT MONDAY FOR
     LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM SUNDAY TO 4 AM EDT MONDAY FOR
     LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM SUNDAY TO 4 AM EDT MONDAY FOR
     LEZ444.

&&

$$

AVIATION.....SC
SHORT TERM...DG
LONG TERM....HLO/DE
MARINE.......HLO


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





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