599
FXUS63 KDTX 312332
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
732 PM EDT FRI OCT 31 2025
KEY MESSAGES
- COOL AND CLOUDY CONDITIONS INTO TONIGHT, ALTHOUGH CONDITIONS
GENERALLY REMAIN DRY.
- THERE IS A CHANCE FOR RAIN SHOWERS TO DEVELOP AGAIN SATURDAY, MAINLY
BETWEEN I-94 AND I-69.
- WINDY CONDITIONS ARE POSSIBLE ON MONDAY. THERE IS A CHANCE THAT
PEAK GUSTS MAY FALL INTO THE 35 TO 45 MPH RANGE. CHANCES FOR RAIN
FAVORED TOWARDS NORTHERN HALF OF THE REGION.
AVIATION
WNW WINDS REMAIN ELEVATED THIS EVENING, BUT ARE EXPECTED TO SETTLE
BELOW 10 KNOTS TONIGHT AS A WEAK SURFACE TROUGH MOVES INTO SOUTHEAST
MICHIGAN. THE COLD AIRMASS IS SUPPORTING PERSISTENT LAKE CLOUDS
WHILE CEILINGS HAVE SETTLED MOSTLY ABOVE 5KFT THIS EVENING AND SHOULD
REMAIN THAT WAY THROUGH THE NIGHT. BRIEF MOMENTS OF DRIZZLE WILL BE
POSSIBLE THIS EVENING, MAINLY TOWARDS MBS, BUT ISOLATED NATURE
PRECLUDES MENTION AT THIS TIME. SIMILAR CONDITIONS WILL CONTINUE INTO
TOMORROW, BUT WIND SPEEDS WILL BE MORE LIGHT AND VARIABLE AT TIMES.
CEILINGS AGAIN LOOK TO SETTLE BETWEEN 3 TO 7 KFT.
FOR DTW/D21 CONVECTION...NO THUNDERSTORM ACTIVITY EXPECTED THROUGH
THE TAF PERIOD.
DTW THRESHOLD PROBABILITIES...
* MODERATE IN CEILINGS AOB 5000 FEET TONIGHT THROUGH TO TOMORROW.
PREV DISCUSSION
ISSUED AT 354 PM EDT FRI OCT 31 2025
DISCUSSION...
CYCLONIC FLOW ACROSS THE GREAT LAKES HAS BEHAVED IN TYPICAL LATE
OCTOBER FASHION, ACTIVATING LAKE MICHIGAN MOISTURE FLUX AND
GENERATING STREAMS OF STRATOCU INTO SE MICHIGAN. MOST NOTABLY IS A
CONVERGENCE AXIS THAT EXTENDS FROM ROUGHLY TVC TO MBS, WHERE A MORE
FOCUSED AXIS OF MOISTURE AND LIGHT RAIN HAVE DEVELOPED. ELSEWHERE,
MOISTURE/FORCING IS TOO SHALLOW TO GENERATE MUCH MORE THAN
SPRINKLES. THUS A FAIRLY SEASONABLE EVENING IS IN STORE WITH
TEMPERATURES RIGHT AROUND 50 DEGREES AND CLOUDY CONDITIONS. POCKETS
OF CLEARING OVERNIGHT AFFORD A WINDOW OF RADIATIVE COOLING TO DROP
OVERNIGHT LOWS INTO THE MID-30S.
THE STACKED LOW CURRENTLY OVER CENTRAL MINNESOTA BECOMES
INCREASINGLY INFLUENTIAL OVERNIGHT AS IT CARVES TOWARD THE OHIO
VALLEY. DEEPER CYCLONIC FLOW WITH THIS SYSTEM GRADUALLY ENGAGES THE
EXISTING LAKE CONVERGENCE AXIS TO ESTABLISH A MORE ORGANIZED
DEFORMATION AXIS BY MID-MORNING SATURDAY. MOIST ISENTROPIC ASCENT
WILL BE MOST PREVALENT IN THE 286-290 K LAYER, BUT WILL LACK DEPTH
OTHERWISE. DO THINK LAKE FLUX WILL WILL PLAY A ROLE IN SATURATING
THE LOW LEVELS, SO FAVORING THE MORE BULLISH OUTCOMES WHICH GENERATE
A NARROW RAIN BAND BETWEEN I-94 AND I-96 BY MID-DAY. INTRODUCED
CHANCE POPS AND A FEW HUNDREDTHS OF QPF AS A STARTING POINT, BUT NOT
OUT OF THE QUESTION TO SEE THIS BAND FLARE UP MORE AGGRESSIVELY OR
FIZZLE OUT DUE TO DRY AIR ALOFT. REGARDLESS, CLOUD COVER THICKENS
AND SHOULD RESULT IN A SLIGHTLY COOLER DAY FOR CENTRAL PORTIONS OF
THE CWA. INFLUENCE OF THE DEFORMATION BAND TAPERS TOWARD THE SAGINAW
VALLEY AND OHIO BORDER, WHERE GREATER SOLAR INSOLATION BOOSTS
TEMPERATURES INTO THE LOW/MID 50S.
THE HEIGHT FALL CENTER AND ASSOCIATED CYCLONIC FLOW GET SHOVED SOUTH
SATURDAY NIGHT, WITH THE DEFORMATION AXIS FALLING APART AS A RESULT.
MAJORITY OF MODEL SOLUTIONS MAINTAIN A THIN/BROKEN LAYER OF LOW
CLOUD THROUGH SUNDAY MORNING TO PREVENT FULL RADIATIVE COOLING, BUT
STILL LOOKING AT TEMPERATURES DROPPING TO OR EVEN A FEW SPOTS BELOW
FREEZING SUNDAY MORNING. MID-LEVEL HEIGHTS THEN BUILD IN BRIEFLY
HEADING INTO THE DAYLIGHT HOURS. HIGH PRESSURE GOVERNS CONDITIONS
THROUGH THE DAY, AFFORDING A QUIET/DRY FORECAST FOR THE LATTER HALF
OF THE WEEKEND.
MODEL VARIANCE INCREASES MONDAY ONWARD AS A MORE DYNAMIC PATTERN
DEVELOPS AND WAVE INTERACTIONS BECOME MORE COMPLICATED. THERE IS
GOOD CONSENSUS AMONG THE GUIDANCE FOR REGION OF DEEP, FORCED ASCENT
TO TRACK ACROSS LOWER MICHIGAN MONDAY-MONDAY NIGHT AS STRONG LOW
PRESSURE TRACKS ACROSS NORTHERN ONTARIO. THE HEIGHT FALL CENTER AND
JET CIRCULATION ARE MAXIMIZED JUST TO OUR NORTH, BUT WILL BE COUPLED
WITH SURFACE CONVERGENCE AS THE SYSTEM'S OCCLUDED FRONT EXTENDS WELL
SOUTH OF THE LOW. DEEP MOISTURE TAPERS OFF WITH SOUTHERN EXTENT, BUT
WILL BE OUR NEXT OPPORTUNITY FOR RAIN ESPECIALLY ACROSS THE SAGINAW
VALLEY AND THUMB REGIONS. ALSO OF NOTE IS THE EXPANSIVE PRESSURE
GRADIENT THAT ACCOMPANIES THIS SYSTEM, RESULTING IN A BREEZY DAY AS
GUSTS LOOK TO APPROACH 30-35 MPH.
MARINE...
A STRONG LOW PRESSURE SYSTEM NOW LOCATED OVER THE CONTINENTAL
NORTHEAST WILL CONTINUE TO PROGRESS INTO THE ATLANTIC WHICH IN TURN
WILL LOOSEN THE PRESSURE GRADIENT ACROSS THE GREAT LAKES. THIS WILL
RESULT IN A QUICK DROP OFF OF WIND SPEEDS AND GUST POTENTIAL LATE
TONIGHT INTO TOMORROW MORNING. SMALL CRAFT ADVISORIES REMAIN IN
EFFECT ACROSS THE MAJORITY OF THE NEARSHORE ZONES. COOLER AIR WILL
FILTER OVER LAKE HURON OVERNIGHT WHICH WILL RESULT IN THE LIKELY
DEVELOPMENT OF A LAKE EFFECT RAIN BAND OR RAIN SHOWERS THROUGH THE
CENTRAL AND SOUTHERN LAKE HURON BASIN. THERE WILL BE A VERY LOW
CHANCE FOR WATER SPOUT DEVELOPMENT WITHIN THIS BAND GIVEN A BOOST IN
LOW-LEVEL CONVERGENCE. OTHERWISE, A WEAK AREA OF HIGH PRESSURE WILL
BUILD OVER THE REGION THROUGH MOST OF THE WEEKEND WHICH WILL
MAINTAIN LIGHTER WINDS. THE NEXT CHANCE FOR BREEZY CONDITIONS AND
RAIN WILL ENTER LATE SUNDAY NIGHT INTO MONDAY WITH THE PASSAGE OF A
COLD FRONT.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR LHZ421-441>443.
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....AA
DISCUSSION...MV
MARINE.......AM
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