943
FXUS63 KDTX 180432
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1132 PM EST WED DEC 17 2025
KEY MESSAGES
- MILD WITH HIGH TEMPS IN THE MID 40S TO AROUND 50 DEGREES ON
THURSDAY.
- WIDESPREAD RAINFALL IS EXPECTED ON THURSDAY, ALONG WITH GUSTY
WINDS OF 30-40 MPH INTO FRIDAY AS WELL.
- THERE IS THE POTENTIAL FOR ANY MOISTURE ON ROADWAYS TO FLASH
FREEZE THURSDAY NIGHT AS ARCTIC AIR MOVES BACK INTO THE REGION.
- SCATTERED-NUMEROUS LIGHT SNOW SHOWERS THURSDAY NIGHT-FRIDAY
MORNING, WITH ISOLATED EMBEDDED SNOW SQUALLS POSSIBLE INTO THE
AFTERNOON. SNOWFALL ACCUMULATIONS UP TO AN INCH IN THE HEAVIEST
ACTIVITY. EXPECT THE FRIDAY MORNING COMMUTE TO BE IMPACTED AND ALLOW
FOR EXTRA TIME.
AVIATION
RESPECTABLE BOUNDARY LAYER COOLING AROUND METRO DETROIT THIS EVENING
UNDER CLEAR SKIES AND LIGHT WINDS HAS LED TO SOME MVFR FOG. THE FOG
SHOULD REMAIN SHALLOW THROUGH THE NIGHT AS RAPID STRENGTHENING OF
THE WIND FIELDS OCCUR ATOP THE SHALLOW NIGHTTIME STABLE LAYER. THESE
INCREASING WINDS (40-50 KNOTS AT 1500 TO 2000 FEET) WILL CONTINUE TO
WARRANT THE MENTION OF LOW LEVEL WIND SHEAR INTO THE EARLY MORNING
HOURS. SUBTLE DAYTIME HEATING AND WARM AIR ADVECTION INTO THE
BOUNDARY LAYER WILL TRANSITION THE LOW LEVEL WIND SHEAR TO GUSTY
WINDS AT THE SURFACE, WITH PEAK GUSTS EXPECTED TO TOP 25 KNOTS THURS
AFTERNOON.
THE INCREASE IN SOUTH WIND FIELDS WILL BE PRECEDING A STRONG SFC
COLD FRONT, FORECAST TO PASS ACROSS SE MI LATE THURS AFTERNOON AND
EVENING. LOW LEVEL MOISTURE ACROSS THE LOWER OHIO VALLEY WILL LIFT
INTO SRN MI DURING THE COURSE OF THE MORNING AS A RESULT OF THE
STRENGTHENING SOUTH FLOW. THIS WILL RESULT IN LOWERING CEILING
HEIGHTS (MVFR TO IFR) DURING THE DAY THURSDAY. BROAD LARGE SCALE
ASCENT ALONG/AHEAD OF THE COLD FRONT AND ASSOCIATED UPPER LEVEL
TROUGH WILL RESULT IN A WIDESPREAD REGION OF RAIN THURS AFTERNOON
AND EARLY EVENING, WITH THE POTENTIAL FOR SOME SHALLOW CONVECTION
ALONG THE SURFACE COLD FRONT.
FOR DTW...THE TRAJECTORY OF THE MOISTURE TRANSPORT SUGGESTS THE
LOWER CLOUDS (MVFR AND IFR) WILL HOLD WEST OF METRO INTO THURS
AFTERNOON. THE COLD FRONT IS FORECAST TO PASS ACROSS METRO BETWEEN
23Z AND 02Z THURS EVENING. THERE IS A CHANCE FOR SOME HIGH INTENSITY
SHOWERS EMBEDDED WITHIN THE BROADER REGION OF LIGHT RAIN DURING THIS
TIME PERIOD.
DTW THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS AOB 5000 FEET THURSDAY AND THURSDAY NIGHT.
* HIGH IN PRECIPITATION TYPE BEING ALL RAIN THURSDAY AND THURSDAY
EVENING.
* LOW IN CROSSWINDS THRESHOLDS BEING EXCEEDED AFTER 08Z FRIDAY.
PREV DISCUSSION
ISSUED AT 337 PM EST WED DEC 17 2025
DISCUSSION...
THE ACTIVE AND PROGRESSIVE JET STREAM ACROSS THE NORTHERN TIER OF
THE CONUS WILL CONTINUE THROUGH THE FORECAST PERIOD WITH ONE OF THE
STRONGEST, MOST DYNAMIC SYSTEMS IN A FEW WEEKS IMPACTING THE REGION
TOMORROW INTO FRIDAY. THIS SYSTEM WILL BRING ABOVE NORMAL
TEMPERATURES AND MODERATE RAINFALL THURSDAY, BOTH OF WHICH WILL AIDE
IN SNOW MELT, AND ALSO ELEVATED WINDS THURSDAY AND FRIDAY, RAPIDLY
FALLING TEMPS THURSDAY NIGHT WITH LIGHT SNOW AND POSSIBLY SQUALLS
INTO FRIDAY BEFORE FINALLY SETTLING DOWN FOR THE WEEKEND.
TEMPERATURES WERE ABLE TO TOUCH 40 AT MOST LOCATIONS ACROSS SE MI
TODAY AS HEIGHTS ROSE A BIT BEHIND THIS MORNINGS TROUGH, AIDED BY
CLEARING SKIES. AS THE UPPER LEVEL TROUGH DIGS INTO THE PLAINS
TONIGHT AND DEEPENS WITH THE INBOUND 160 KNOT UPPER LEVEL JET,
DOWNSTREAM RIDGE AMPLIFICATION WILL LEAD TO MORE RAPIDLY BUILDING
HEIGHTS AND WARM AIR ADVECTION WITH STRONG SOUTHERLY LOW LEVEL JET
KICKING IN SO EXPECTING HIGHS INTO THE MID TO UPPER 40S THURSDAY.
SOME SOUTHERN LOCATIONS MAY TOUCH 50 AS WELL.
THURSDAY WILL ALSO BE A WET DAY WITH PREFRONTAL RAIN DEVELOPING
THROUGH THE DAY AND POSSIBLE CONVECTIVE RAIN ALONG THE STRONG COLD
FRONT IN THE EVENING. LOCAL PROBABILISTIC GUIDANCE SHOWS ABOVE AN
80% CHANCE FOR ALL LOCATIONS TO RECEIVE A QUARTER INCH OF RAINFALL
FROM ABOUT 18-06Z AND MAINLY LESS THAN A 20% CHANCE TO REACH A HALF
INCH. NATIONAL GUIDANCE FALLS IN LINE WITH THIS AS THE MEAN VALUE
FOR THE 12 HOUR PERIOD IS ROUGHLY 0.3-0.4 INCHES WITH 90% PERCENTILE
VALUES REACHING 0.5-0.6 INCHES. SO CURRENT FORECAST FOR AROUND 0.4
IS VERY REASONABLE. ADDING SNOW MELT WHICH CURRENTLY HOLDS AROUND 0.5-
1.0 INCHES OF WATER, DO EXPECT SOME RISES IN LOCAL WATERWAYS BUT
CURRENT GUIDANCE SUGGESTS IT WON'T BE ENOUGH TO CAUSE FLOODING.
FRONTAL PASSAGE IN THE EVENING THEN OPENS THE DOOR FOR RAPID COOLING
WITH 850MB TEMPS DROPPING FROM 6C AT 00Z, -2C AT 06Z AND -11C BY
12Z. RESIDUAL WATER ON ROADS MAY RAPIDLY FREEZE AS AIR TEMPS QUICKLY
DROP INTO THE MID TO UPPER 20S AFTER DARK. ADDITIONALLY, THE STRONG
COLD WESTERLY WINDS WILL EXCITE LAKE EFFECT WITH BANDS OF SNOW
WORKING EAST ACROSS LOWER MI. STILL NO REAL STRONG SIGNAL WITH LOW
LEVEL CONVERGENCE WHICH WOULD SUGGEST HIGHER CONFIDENCE FOR ANY
CORRIDOR TO OVERACHIEVE WITH LAKE EFFECT BANDS SETTING UP. STILL,
STRONG WINDS AND SNOW OVERNIGHT THURSDAY INTO FRIDAY MORNING WILL
OFFER A CHANCE FOR BRIEF SNOW SQUALLS. CURRENTLY ONLY THINKING
AROUND A HALF INCH OF SNOW IS MOST LIKELY AS MIXING DEPTHS ARE
TOPPING OUT AROUND 5KFT. THOUGH THIS DOES PASS THROUGH THE DGZ, IT'S
A BIT SHALLOWER THAN WE'D LIKE TO SEE FOR HIGHER END LAKE EFFECT.
AS BRIEFLY MENTIONED, WINDS WILL BE ELEVATED THURSDAY AND FRIDAY.
THURSDAY WILL BE PREFRONTAL SOUTH/SOUTHEASTERLY WINDS BUT A STRONG
INVERSION WILL PREVENT MIXING DOWN THE STRONGEST OF WINDS WITH MOST
MODELS TOPPING GUSTS OFF AROUND 20-30 MPH OVER LAND. FRIDAY WINDS
WILL BE STRONGER AS THE COLD ADVECTION HELPS MIXING DEPTHS INCREASE
TO AROUND 5KFT. PROBABILISTIC GUIDANCE SHOWS THE ONLY CHANCE (LESS
THAN 20%) FOR THE NORTHERN THUMB TO HIT 45 MPH WITH GUSTS. MOST OF
THE GUIDANCE CENTERS IN THE 30-40 MPH RANGE. SO AN ISOLATED GUST
COULD REACH WIND ADVISORY CRITERIA, BUT DOESN'T LOOK TO BE THE NORM.
HIGH PRESSURE BUILDS BACK ACROSS THE OHIO VALLEY AND UP INTO MI
THROUGH THE DAY FRIDAY AND LINGERING THROUGH SATURDAY. THIS WILL BE
SHORT LIVED THOUGH AS THE PROGRESSIVE PATTERN HOLDS AND THE NEXT LOW
TRACKING THROUGH ONTARIO BRINGS THE NEXT COLD FRONT THROUGH LOWER MI
SATURDAY EVENING OR OVERNIGHT.
MARINE...
QUIET CONDITIONS PERSIST THROUGH THE EVENING, FOLLOWED BY WINDS
QUICKLY ORGANIZING OUT OF THE SOUTH OVERNIGHT AS LOW PRESSURE TRACKS
ALONG THE CONUS-CANADA BORDER. LOW LEVEL WINDS AHEAD OF THIS LOW
INTENSIFY RAPIDLY THURSDAY, APPROACHING 70 KNOTS AT 850MB. WARM AND
STABLE CONDITIONS PREVENT THIS MAGNITUDE OF WINDS FROM REACHING THE
SURFACE, BUT EVEN THE SHALLOW MIXING DEPTHS WILL STILL BE CAPABLE OF
35-40 KNOT GUSTS ACROSS THE OPEN WATERS. A GALE WARNING HAS BEEN
ISSUED AS A RESULT. HIGHER STABILITY TOWARD THE SHORELINE KEEPS
GUSTS AROUND 30 KNOTS, ALTHOUGH OVERACHIEVEMENT IN MIXING MAY
REQUIRE AN OBSERVATION-BASED UPGRADE FOR THE NEARSHORE ZONES. THE
LOW EVENTUALLY DRAWS A COLD FRONT ACROSS THE GREAT LAKES THURSDAY
EVENING, AFFORDING A BRIEF LULL IN WIND GUSTS BEFORE RAMPING BACK UP
EARLY FRIDAY MORNING AS STRONG COLD ADVECTION BEGINS. THE COLDER AIR
ERODES STABILITY TO SUPPORT A SECOND WAVE OF GALE FORCE GUSTS, THIS
TIME OUT OF THE WEST-NORTHWEST AND FOR BOTH THE NEARSHORE AND OPEN
WATERS. IN ADDITION TO WIND/WAVE CONCERNS, THE FRONT WILL ALSO FOCUS
A BAND OF RAIN SHOWERS ACROSS THE GREAT LAKES THURSDAY EVENING
FOLLOWED BY A TRANSITION TO LAKE ENHANCED SNOW FOR FRIDAY. SNOW
SQUALLS WILL BE POSSIBLE GIVEN THE GUSTY WINDS. HIGH PRESSURE THEN
ARRIVES FRIDAY NIGHT, BRINGING A BRIEF REPRIEVE FROM THE ACTIVE
STRETCH, ALTHOUGH YET ANOTHER LOW PRESSURE SYSTEM TRACKS THROUGH
ONTARIO SATURDAY NIGHT-SUNDAY WHICH CARRIES ADDITIONAL GALE
POTENTIAL.
HYDROLOGY...
MILDER TEMPERATURES BRING SNOW MELT ACROSS THE AREA AND WIDESPREAD
RAINFALL IS EXPECTED THURSDAY FROM LATE MORNING INTO THE EVENING.
MAXIMUM SNOW WATER EQUIVALENT IN THE DEEPER SNOW PACK IS CURRENTLY
AROUND 1 INCH. BASIN AVERAGE RAINFALL TOTALS AROUND HALF AN INCH ARE
EXPECTED, WHICH WITH THE SNOW MELT MAY LEAD TO PONDING ON ROADWAYS.
RISES ON AREA RIVERS ARE LIKELY LATE THIS WEEK, BUT FLOOD CONDITIONS
ARE NOT ANTICIPATED.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...GALE WARNING UNTIL 7 PM EST FRIDAY FOR LHZ361>363-462.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST THURSDAY NIGHT FOR LHZ421-
441>443.
GALE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY EVENING FOR
LHZ421-422-441>443.
LOW WATER ADVISORY FROM 7 AM THURSDAY TO 7 PM EST FRIDAY FOR LHZ422.
SMALL CRAFT ADVISORY FROM 7 AM THURSDAY TO MIDNIGHT EST THURSDAY
NIGHT FOR LHZ422.
GALE WARNING FROM 7 AM THURSDAY TO 7 PM EST FRIDAY FOR LHZ463-464.
LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 7 AM THURSDAY TO 7 PM EST FRIDAY FOR
LCZ460.
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 7 AM THURSDAY TO 7 PM EST FRIDAY FOR
LEZ444.
AVIATION.....SC
DISCUSSION...DRK
MARINE.......MV
HYDROLOGY....SF
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AT WWW.WEATHER.GOV/DETROIT.
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