559
FXUS63 KDTX 200845
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
445 AM EDT SUN JUL 20 2025
KEY MESSAGES
- DRY WITH SEASONABLE TEMPERATURES THROUGH TUESDAY.
- HOT AND HUMID WEDNESDAY AND THURSDAY WITH HEAT INDEX APPROACHING
100 DEGREES POSSIBLE ON THURSDAY.
- LOW CHANCE OF SHOWERS AND THUNDERSTORMS NORTH OF I-69
WEDNESDAY. HIGHER AND MORE WIDESPREAD CHANCES THURSDAY AND FRIDAY.
AVIATION
CHAOTIC LIFR/IFR/MVFR LOW CLOUDS ACROSS SOUTHEAST MICHIGAN AS WEAK
COLD FRONT SINKS SOUTH. BRIEF LIGHT SHOWER POSSIBLE NEAR THE START
OF THE TAF PERIOD ACROSS THE SOUTHERN TAFS BEFORE THE FRONT CLEARS.
LIGHT NORTHERLY WINDS THEN TAKE HOLD TODAY WITH MVFR CLOUDS LATE IN
THE MORNING CONTINUING TO SLOWLY LIFT AND BEGIN TO DISSIPATE IN THE
LATE AFTERNOON AS DRIER AIR FILTERS IN. CLEAR TO MOSTLY CLEAR SKIES
FOR TONIGHT WITH VERY LIGHT NORTHEAST WINDS. AS SUCH, SOME MARINE
INFLUENCE COULD PRODUCE LIGHT FOG/LOW CLOUDS, BUT CONFIDENCE IS VERY
LOW AND BEST CHANCE WOULD BE FNT & PTK.
FOR DTW/D21 CONVECTION...THUNDERSTORMS ARE NOT EXPECTED.
THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS AOB 5000 FEET INTO THE AFTERNOON HOURS. LOW THIS
EVENING.
PREV DISCUSSION
ISSUED AT 346 AM EDT SUN JUL 20 2025
DISCUSSION...
WEAK LOW PRESSURE SYSTEM AND COLD FRONT ARE WORKING THROUGH THE STATE
THIS MORNING. AMPLE LOW LEVEL MOISTURE WITH DEWPOINTS TOPPING 70
DEGREES IS SUPPORTING HIGH COVERAGE OF LOW CLOUDS AND ISOLATED SPOTS
PATCHY FOG. COLD FRONT WILL SETTLE SOUTH OF THE STATE TOWARDS THE
END OF THE MORNING AND SETTLE TOWARDS THE OHIO VALLEY FOR THE
AFTERNOON AND EVENING. COMBINATION OF DIURNAL MIXING AND ARRIVAL OF
DRY AIR WILL HELP LIFT LOWER CLOUDS THROUGH THE MORNING, THOUGH THE
COOLER NORTHERLY FLOW SHOULD MAINTAIN A DECENT COVERAGE OF CLOUDS
THROUGH MUCH OF THE DAY. THE INFLUENCE OF A HIGH PRESSURE CENTERED
TOWARDS LAKE SUPERIOR TODAY WILL INCREASE THE STABLE CONDITIONS
LOCALLY AND BRING A MOSTLY DRY FORECAST. THE ONE EXPECTATION MAY BE
ALONG THE SOUTHERN BORDER WHERE SHOWERS AND POSSIBLY A BRIEF
THUNDERSTORM MAY GRAZE THE STATE LINE GIVEN THE PROXIMITY OF THE
FRONT AND CONVECTION BEING SUPPORTED ALONG THE FRONT THROUGHOUT THE
DAY. LOWER POPS UP TO 20 PCT WILL COVER THIS. POST FRONTAL AIRMASS
WILL DROP HIGH TEMPERATURES TODAY BACK DOWN TO THE AVERAGE OR A FEW
DEGREES BELOW (UPPER 70S TO LOW 80S).
THERE WILL BE AN EXPANSION OF THE UPPER LEVEL RIDGE FROM THE
MISSISSIPPI RIVER VALLEY TO THE GREAT LAKES INTO THE MIDDLE OF THE
WEEK WHILE THE SURFACE HIGH PRESSURE SLIDES EAST TUESDAY TOWARDS THE
ATLANTIC. THE RESULT WILL BE A WARMING TREND EARLY TO MID WEEK. THE
INCREASING SOUTH TO SOUTHWEST LOWER LEVEL FLOW WILL USHER IN 850 MB
TEMPERATURES TO 20C OR GREATER BY WEDNESDAY BRINGING HIGHS TO AROUND
90. SOLID MOISTURE ADVECTION WILL ALSO ACCOMPANY THE HEAT WITH
DEWPOINTS INCREASING WELL INTO THE 60S TO 70 DEGREES. THE STRENGTH OF
THE RIDGE SHOULD KEEP MOST OF THE AREA DRY THROUGH WEDNESDAY, THOUGH
LOWER END POPS WILL REMAIN IN THE FORECAST ACROSS THE TRI- CITIES
AND NORTHERN THUMB AS SHORTWAVES TRIGGER A POSSIBLE CONVECTIVE
COMPLEX THAT WILL RIDE THE NORTHERN END OF THE RIDGE AND MAINLY IMPACT
NORTHERN MI AND PARTS OF NORTHERN LOWER MI. ANOTHER HOT AND HUMID
DAY MAY BE IN STORE FOR THURSDAY. HOWEVER, HIGHS INTO THE 90S EACH
DAY WILL ULTIMATELY DEPEND ON WHAT THE OVERALL CLOUD COVER AND
EVOLUTION OF PRECIPITATION ENDS UP BEING GIVEN THE NEARBY CHANCES
WEDNESDAY AND THE MID TO LATE DAY CHANCES ON THURSDAY. THURSDAY INTO
FRIDAY PROSPECTS FOR PRECIPITATION LOOK BETTER AS CANADIAN TROUGHING
WILL DRAW A COLD FRONT TROUGH THE GREAT LAKES AND SHOULD SUPPORT THE
BEST CHANCE FOR RAIN DURING THE WEEK.
MARINE...
QUIET MARINE CONDITIONS TAKE OVER BEHIND A COLD FRONT TODAY.
NORTHERLY WINDS ALSO PREVAIL AS HIGH PRESSURE BEGINS TO BUILD IN
OVER THE AREA. THE HIGH PRESSURE WILL HOLD ACROSS THE REGION THROUGH
MONDAY INTO TUESDAY KEEPING DRIER CONDITIONS AND LIGHTER WINDS IN
PLACE. WINDS SLOWLY VEER TO THE EAST AS A WARM FRONT LOOK SOT MOVE
IN FROM THE MIDWEST. THIS WILL BRING THE NEXT CHANCES FOR
THUNDERSTORMS TUESDAY NIGHT INTO WEDNESDAY.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....SF
DISCUSSION...AA
MARINE.......AA
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