031
FXUS63 KDTX 061152
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
652 AM EST THU NOV 6 2025
KEY MESSAGES
- WIDESPREAD RAIN SHOWERS MOVE ACROSS THE AREA LATE TONIGHT-FRIDAY
MORNING.
- TURNING MUCH COLDER OVER THE WEEKEND WITH A CHANCE OF THE FIRST
ACCUMULATING SNOW OF THE SEASON BY SUNDAY.
- HIGH TEMPERATURES LIMITED TO THE UPPER 30S WITH LOWS IN THE LOWER
20S SUNDAY AND MONDAY. SCATTERED LAKE EFFECT SNOW SHOWERS ALSO
LIKELY DURING THIS TIMEFRAME.
AVIATION
DEEP RIDGING AND SURFACE HIGH PRESSURE WILL LEAD TO VFR CONDITIONS
TODAY AND THROUGH MUCH OF TONIGHT. ABRUPT THETAE ADVECTION AND
FRONTAL DYNAMICS WILL BRING A PERIOD OF WIDESPREAD RAIN DURING THE
DAYTIME FRIDAY. DID INTRODUCE A START TIME OF 10 TO 11Z FOR THE
ONSET OF MVFR CIGS/VSBY RAIN.
DTW THRESHOLD PROBABILITIES...
* NONE.
PREV DISCUSSION
ISSUED AT 310 AM EST THU NOV 6 2025
DISCUSSION...
COLDER START TO THE MORNING AS CLEAR SKIES AND LIGHT WINDS OFFERED
EFFICIENT RADIATIVE COOLING OVERNIGHT DROPPING TEMPS TO AROUND 30
WITH SOME AREAS FALLING INTO THE 20S. NORTHERN EDGE OF HIGH PRESSURE
SLIDING ALONG THE OHIO VALLEY IN PLACE OVER SE MI TODAY MAINTAINING
DRY CONDITIONS AND LIGHTER WESTERLY WINDS. WINDS EVENTUALLY VEER TO
THE SOUTH LATE DAY AS THE RIDGE AXIS SHIFTS TO THE EASTERN GREAT
LAKES. ENERGETIC NORTHERN JET OVER THE CONUS LEADS TO A ACTIVE
PATTERN TO END THE WEEK WITH A SERIES OF PACIFIC NORTHWEST
SHORTWAVES EJECTING TOWARDS THE PLAINS/GREAT LAKES. FIRST OF THESE
ARRIVE OVER THE NORTHERN PLAINS LATE TONIGHT SPURRING CYCLOGENSIS
OVER THE FAR NORTHERN MISSISSIPPI RIVER VALLEY. DEEPENING LOW
PRESSURE IS PROGGED TO LIFT OVER THE UP/LAKE SUPERIOR EARLY FRIDAY
AS THE TIGHTENING GRADIENT STRENGTHENS SOUTHERLY FLOW INTO SOUTHERN
LOWER MI WITH A 45-50KT LLJ DEVELOPING. IN ADDITION TO SUPPORTING
BREEZY DAY WITH PEAK GUSTS UP AROUND 25MPH, THIS JET DRIVES ROBUST
MOISTURE TRANSPORT INTO THE AREA AS PW VALUES NEAR 1" (WITHIN THE
90TH PERCENTILE FOR EARLY NOVEMBER). LEAD COLD FRONT CROSSES SE MI
LATE MORNING-AFTERNOON GENERATING A BAND OF LIGHT TO MODERATE
SHOWERS IN ADVANCE BEFORE CLEARING EAST BY EVENING. A SECONDARY COLD
FRONT IS THEN SET TO SWING THROUGH SOUTHERN LOWER MI FRIDAY NIGHT
BRINGING A LOW CHANCE FOR A FEW ADDITIONAL LIGHT SHOWERS. THIS FRONT
MARKS THE LEAD EDGE OF AN ARCTIC ORIGINATING AIRMASS THAT SINKING
SOUTH OVER NORTHERN MANITOBA/ONTARIO.
A SECOND, MORE POTENT, PACIFIC NORTHWEST SHORTWAVE QUICKLY ARRIVES
OVER THE MIDWEST SATURDAY. MODEL FAMILIES REMAIN CONVERGED ON THE
ASSOCIATED SURFACE LOW TRACKING OVER NORTH-CENTRAL OHIO LATE
SATURDAY NIGHT-EARLY SUNDAY THOUGH STILL SOME SUBTLE DIFFERENCES IN
EXACT NORTH-SOUTH POSITIONING. THE SPEED AT WHICH THIS WAVE PHASES
WITH A BROAD HUDSON BAY MID-UPPER TROUGH HOWEVER HAS NOT BEEN FULLY
RESOLVED. THAT SAID, THERE HAS BEEN A TREND IN THE 00Z GUIDANCE IN A
SLOWER WAVE INTERACTION FAVORING A FLATTER, MORE OPEN LOW QUICKLY
PUSHING INTO THE NORTHEASTERN US BY LATE SUNDAY. THIS OUTCOME
REDUCES RESIDENCE TIME OVER SE MI RESULTING IN RELATIVE LOWER QPF,
THOUGH STILL OFFERS THE REGION'S FIRST SNOW CHANCES OF THE SEASON.
VERY HIGH CONFIDENCE IN THE MAGNITUDE OF COLD AIR THAT FOLLOWS THIS
SYSTEM AS THE NOW HIGHLY AMPLIFIED HUDSON BAY UPPER TROUGH SETTLES
OVER THE GREAT LAKES. THIS ALLOWS THE AFOREMENTIONED ARCTIC AIRMASS
(NOW PARTIALLY MODIFIED FROM ITS TREK SOUTH) TO HOLD OVER LOWER
SUNDAY INTO TUESDAY AS 850MB TEMPS CRATER TOWARDS -12C, WELL WITHIN
THE 10TH PERCENTILE CLIMATOLOGY. END RESULT IS THE FIRST TASTE OF
WINTER AS HIGHS ONLY TOP OUT IN THE 30S SUNDAY AND MONDAY (SOME
LOWER 40S POSSIBLE BY TUESDAY) WITH OVERNIGHT LOWS EACH OF THOSE
NIGHTS IN THE LOWER 20S. SCATTERED LAKE EFFECT SNOW SHOWERS ARE ALSO
LIKELY BOTH LATE SUNDAY, FOLLOWING THE DEPARTURE OF SYNOPTIC PRECIP,
AND MONDAY. LONG RANGE MODEL SOLUTIONS DO HINT AT SOME MODERATION IN
TEMPS BY MIDWEEK THOUGH STILL AT LEAST SLIGHTLY BELOW AVERAGE.
MARINE...
HIGH PRESSURE PASSING THROUGH THE OHIO VALLEY WEAKENS THE GRADIENT
IN PLACE OVER THE CENTRAL GREAT LAKES TODAY, CAUSING NORTHWEST WIND
TO CONTINUE TO SUBSIDE. AS THE HIGH PASSES EAST THIS EVENING, FLOW
ORGANIZES OUT OF THE SOUTHWEST BEFORE BACKING TO SOUTH ON FRIDAY IN
RESPONSE TO LOW PRESSURE TRACKING ACROSS THE NORTHERN GREAT LAKES.
SOUTH WIND BECOMES GUSTY THROUGH THE DAY FRIDAY, PEAKING DURING THE
MORNING WITH GUSTS OF AROUND 25 TO 30 KT. LATEST GUIDANCE PRESENTS A
40% CHANCE FOR A 1 TO 3 HOUR PERIOD OF LOW-END GALES ACROSS PORTIONS
OF CENTRAL LAKE HURON BETWEEN 06Z AND 12Z. THE LOWER CONFIDENCE AND
BREVITY OF THE EVENT PRECLUDES A GALE HEADLINE AT THIS STAGE BUT
WILL CONTINUE TO MONITOR TRENDS IN GUIDANCE TODAY. WIDESPREAD RAIN
WILL ALSO ACCOMPANY THIS SYSTEM FRIDAY BEFORE THE COLD FRONT BRINGS
IN DRIER AIR LATE. POST-FRONTAL NORTHWEST WIND IS FORECAST TO PEAK
AROUND 20 TO 25 KT FRIDAY NIGHT. THE NEXT LOW PRESSURE SYSTEM WILL
TRACK ACROSS THE SOUTHERN GREAT LAKES SATURDAY NIGHT INTO SUNDAY.
DETAILS ARE YET TO BE DETERMINED REGARDING SYSTEM STRENGTH AND
TRACK, BUT THIS SYSTEM WILL LIKELY PULL A MUCH COLDER AIR MASS
ACROSS THE REGION FOR THE EARLY WEEK. THE POTENTIAL IS INCREASING
FOR GUSTY NORTHERLY WINDS AND SNOW DURING THE DAYLIGHT PERIOD SUNDAY.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR LHZ441-442.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....CB
DISCUSSION...KDK
MARINE.......TF
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