087
FXUS63 KDTX 121732
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
132 PM EDT FRI SEP 12 2025
KEY MESSAGES
- DRY AND WARM AGAIN TODAY WITH HIGHS AROUND 80.
- CHANCE OF SCATTERED SHOWERS AND AN ISOLATED EMBEDDED THUNDERSTORM
SATURDAY MORNING THROUGH LATE AFTERNOON.
- MUCH ABOVE NORMAL HIGHS WITH CONTINUING DRY WEATHER SUNDAY THROUGH
MIDWEEK.
AVIATION
HIGH PRESSURE CENTERED OVER SOUTHERN QUEBEC AND THE EASTERN GREAT
LAKES CONTINUES TO DOMINATE THE WEATHER THROUGH THE PERIOD. THIS
MAINTAINS STABLE, VFR CONDITIONS WITH A DIURNAL CU FIELD BASED
AROUND 5 TO 6 KFT AND LIGHT SOUTHERLY WIND. BOUNDARY LAYER CLOUD
DISSIPATES WITH THE LOSS OF DAYTIME HEATING, THEN MID AND UPPER
CLOUDS FILL IN OVERNIGHT INTO SATURDAY MORNING AHEAD OF AN UPPER
DISTURBANCE DROPPING INTO THE WESTERN GREAT LAKES. A WEAK SOUTHERLY
GRADIENT WIND IS EXPECTED TO HOLD THROUGH THE NIGHT WHICH SHOULD
HELP KEEP THE MOIST MARINE LAYER OFFSHORE, MITIGATING FOG CONCERNS
OVERNIGHT. THE UPPER DISTURBANCE WILL BRING POTENTIAL FOR LATE
MORNING SHOWERS, BUT CONFIDENCE REMAINS LOW FOR THIS ACTIVITY TO
REACH SOUTHEAST MI AS LOW-LEVEL DRY AIR HOLDS IN PLACE.
FOR DTW/D21 CONVECTION... THUNDERSTORMS ARE NOT ANTICIPATED THROUGH
SATURDAY.
THRESHOLD PROBABILITIES...
* NONE.
PREV DISCUSSION
ISSUED AT 330 AM EDT FRI SEP 12 2025
DISCUSSION...
LIGHT EASTERLY FLOW OFF LAKE HURON HAS SUPPORTED A ROBUST FOG
RESPONSE ACROSS MUCH OF THE THUMB/SAGINAW VALLEY LAST NIGHT WITH
DEVELOPMENT MUCH PATCHIER FOR THE REST OF SE MI. AREAS OF FOG BURN
OFF THIS MORNING AS THE REGION STILL HOLDS UNDER THE INFLUENCE OF
HIGH PRESSURE NOW CENTERING OVER SOUTHWESTERN ONTARIO. LARGELY A
PERSISTENCE FORECAST TODAY AS A RESULT WITH WINDS REMAINING VERY
LIGHT NOW OUT OF A GENERALLY SOUTHERLY DIRECTION (RANGING SW TO SE)
WITH SKIES TURNING PARTLY CLOUDY FROM DIURNAL CUMULUS. RIDGE AXIS
SHIFT TO OUR EAST AND THE SUBSEQUENT WIND SHIFT SETS UP VERY MODEST
WAA (850MB TEMPS NUDGE UP 1-2C) SUPPORTING SLIGHTLY WARMER HIGHS
COMPARED TO THURSDAY WITH MOST AREAS LIKELY REACHING AROUND 80 IF
NOT LOWER 80S. COOLER NIGHT (LOWS IN THE 50S) IN STORE AGAIN TONIGHT
AS SKIES CLEAR OVER VERY LIGHT TO NONEXISTENT WINDS LEADING TO
EFFICIENT RADIATIVE COOLING.
CENTRAL CONUS RIDGING AMPLIFIES TONIGHT/SATURDAY AS A WEAK SHORTWAVE
RIDES OVER TOP TOWARDS THE WESTERN GREAT LAKES. BULK OF MODEL
GUIDANCE CONTINUES TO ADVERTISE THIS WAVE DIVING SOUTHEAST ACROSS
SOUTHERN LAKE MICHIGAN INTO NORTHERN IN/FAR SOUTHWESTERN MI SATURDAY
MORNING. WITH NOCTURNAL LOW LEVEL JET FORCING OVER THE UPPER
MISSISSIPPI NOT KEEPING PACE TO THE ASSOCIATED CLUSTER OF
SHOWERS/STORMS, THIS CONVECTION BEGINS TO DECAY WHILE CROSSING THE
STATE. ADDITIONALLY THE MAJORITY OF RAIN HOLDS TO OUT SOUTHWEST
GIVEN THE SHORTWAVE TRACK. END RESULT LOCALLY IS A LOWER END CHANCE
(20-30%) SATURDAY MORNING THRU LATE AFTERNOON FOR SCATTERED SHOWERS
AND ISOLATED EMBEDDED THUNDER.
OTHERWISE EXTENDED PERIOD OF DRY, SEASONABLY HOT WEATHER CONTINUES
NEXT WEEK AS AN OMEGA BLOCK FORMS ACROSS THE CONUS WITH THE RIDGE
FOCUSED OVER THE MIDWEST/GREAT LAKES. HIGHS SUNDAY THROUGH
POTENTIALLY THURSDAY TOP OUT IN THE MID TO UPPER 80S, A SOLID 10+
DEGREES ABOVE MID-SEPTEMBER NORMALS. COOLER OVERNIGHT LOWS IN THE
50S ALSO LOOK TO PERSIST DURING THIS TIMEFRAME THANKS TO HIGH
PRESSURE PROMOTING CLEAR NIGHT SKIES AND LIGHT WINDS.
MARINE...
PATCHY FOG THAT DEVELOPED NEAR THE SHORELINE EARLY THIS MORNING WILL
BEGIN TO MIX OUT AFTER SUNRISE. DRY CONDITIONS AND GRADUALLY VEERING
WIND PROFILES THEN CHARACTERIZE MOST OF THE DAYTIME HOURS AS HIGH
PRESSURE DRIFTS TOWARD NEW ENGLAND. HUDSON BAY LOW PRESSURE CARVES
INTO THE EASTERN GREAT LAKES THIS WEEKEND, SENDING AN UPPER LEVEL
DISTURBANCE INTO LAKE HURON SATURDAY FOLLOWED BY A COLD FRONT
SATURDAY NIGHT. BOTH FEATURES GENERATE LOW COVERAGE/LOW IMPACT
SHOWER POTENTIAL AS THEY STRUGGLE TO ACCESS MOISTURE. A SECOND HIGH
PRESSURE CENTER OVER ONTARIO EXPANDS BACK INTO THE GREAT LAKES
SUNDAY AND PERSISTS THROUGH EARLY NEXT WEEK MARKING THE RETURN OF
DRY WEATHER AND CONTINUING THE STRETCH OF FAVORABLE MARINE
CONDITIONS.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....TF
DISCUSSION...KDK
MARINE.......MV
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