708
FXUS63 KDTX 181146
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
646 AM EST THU DEC 18 2025
KEY MESSAGES
- MILD WITH LATE DAY/EARLY EVENING TEMPS IN THE MID 40S TO LOWER 50S
TOWARD THE SOUTHERN MICHIGAN BORDER.
- OCCASIONAL RAIN TODAY, WITH WIDESPREAD RAINFALL LATE IN THE
DAY/EARLY THIS EVENING, ALONG WITH GUSTY WINDS OF 30-40 MPH,
ESPECIALLY ON FRIDAY.
- 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 LATE TONIGHT-FRIDAY MORNING,
WITH ISOLATED EMBEDDED SNOW SQUALLS POSSIBLE INTO THE AFTERNOON.
SNOWFALL ACCUMULATIONS OF A DUSTING TO PERHAPS AN INCH IN THE
HEAVIEST ACTIVITY. EXPECT THE FRIDAY MORNING COMMUTE TO BE IMPACTED
AND ALLOW FOR EXTRA TIME.
AVIATION
FULL LATITUDE TROUGH ADVANCING THROUGH THE GREAT PLAINS AND
MISSISSIPPI RIVER VALLEY WILL RESULT IN DEEP MERIDIONAL MOISTURE
TRANSPORT INTO SOUTHEAST MICHIGAN TODAY. MOISTURE ADVECTION WILL
RAMP UP MOMENTARILY EVIDENCED BY MVFR CEILINGS AND REPORTED RAIN
LIFTING INTO SOUTHWEST LOWER MICHIGAN. EARLY RAIN WILL REMAIN
SOMEWHAT SPOTTY AND LIMITED TO THE NORTHERN TAF SITES, BEFORE
WIDESPREAD RAIN MOVES IN FOR THE AFTERNOON PRIMARILY BETWEEN 21-03Z.
FORCED CONVECTIVE LINE FEATURE IS PROGGED BY MODEL DATA TO PUSH
ACROSS THE TAF SITES ALONG THE WIND SHIFT SOMETIME BETWEEN 00-02Z.
BRIEF HEAVIER RAINFALL RATES ALONG WITH WEST WIND GUSTS EXCEEDING 30
KNOTS WILL BE POSSIBLE WITH THIS ACTIVITY. ABRUPT COLD ADVECTION
TONIGHT WITH FALLING TEMPERATURES WILL SUPPORT A CHANGEOVER TO SNOW
AS PRECIPITATION TYPE AFTER 06Z. LOW CONFIDENCE EXISTS ON TIMING AND
COVERAGE OF SNOW SHOWERS LATE TONIGHT.
FOR DTW...LATEST DATA SUPPORTS A LATER ARRIVAL OF MVFR AND IFR
CEILINGS AT DTW THIS AFTERNOON. KEPT WITH 21Z TIMING. CONVECTIVE
LINE ALONG THE WIND SHIFT BRINGS POTENTIAL FOR HEAVIER RAINFALL
RATES AND WEST WINDS EXCEEDING 30 KNOTS. TIMED IT AT DTW BETWEEN 01-
03Z. SNOW SHOWERS POSSIBLE LATE TONIGHT BUT UNCERTAIN ON TIMING.
DTW THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS AOB 5000 FEET TODAY AND TONIGHT.
* HIGH IN PRECIPITATION TYPE BEING ALL RAIN THURSDAY AND THURSDAY
EVENING. HIGH CONFIDENCE IN SNOW AS A PRECIPITATION TYPE AFTER 06Z
FRIDAY.
* MEDIUM IN CROSSWINDS THRESHOLDS BEING EXCEEDED AFTER 08Z FRIDAY.
PREV DISCUSSION
ISSUED AT 300 AM EST THU DEC 18 2025
DISCUSSION...
TIGHT CIRCULATION AND STRONG UPPER LEVEL WAVE TRACKING THROUGH NORTH
DAKOTA THIS MORNING WITH ADDITIONAL UPPER LEVEL ENERGY/JET DROPPING
SOUTHEAST ON THE BACKSIDE INTO THE CENTRAL PLAINS. MASSIVE AREA OF
AGGRESSIVE 500 MB HEIGHT FALLS THIS EVENING, WITH -140 M FROM LOWER
MICHIGAN TO KENTUCKY. SUBSEQUENTLY, A VERY STRONG SOUTH-SOUTHWEST
LOW LEVEL JET (70 KNOTS) WILL TRACK THROUGH SOUTHEAST MICHIGAN EARLY
THIS EVENING, TRANSPORTING NEAR RECORD MOISTURE FOR MID DECEMBER
STANDARDS, AS NAM/HRRR INDICATING 850 MB DEW PTS OF 7 C. 00Z
REGIONAL GEM/HRRR WERE ALSO VERY AGGRESSIVE WITH SURFACE DEW PTS,
REACHING NEAR 50 DEGREES, WHICH SEEMS A BIT AGGRESSIVE. HOWEVER, DO
THINK IT IS PRUDENT TO CARRY MAX TEMPS AROUND 50 DEGREES ACROSS
DETROIT METRO AREA AND POINTS SOUTH. FOR REFERENCE, THE RECORD HIGH
AT DETROIT FOR TODAY IS 54 DEGREES SET IN 1939.
ALTHOUGH THERE WILL BE OCCASIONAL LIGHT RAIN SHOWERS INCREASING IN
COVERAGE DURING THE DAY, THE MAIN SHOW IS IN THE 22-04Z WINDOW AS
THE VERY IMPRESSIVE COLD FRONT TRACKS THROUGH. THE WIND SHIFT FROM
SOUTH TO WEST WILL BE DRAMATIC, AND WILL BE CONDUCIVE FOR A ROPE
LIKE FEATURE/THIN LINE OF HIGHER REFLECTIVE/HEAVIER RAIN EMBEDDED
WITHIN A LARGER SWATH OF RAIN. THESE NARROW LINES BRING CONCERN FOR
HIGH WINDS (> 45 MPH) AS THEY ATTEMPT TO TAP INTO THE DEPARTING
STRONG LOW LEVEL JET. CAN'T EVEN RULE OUT THUNDER WITH THE STRONG
FORCING, BUT SHOWALTER INDICES DO LOOK TO STAY POSITIVE. BANKING ON
ENOUGH NEAR SURFACE STABILITY WITH THE FROZEN GROUND OVER SOUTHERN
MICHIGAN TO KEEP WIND GUSTS IN CHECK, BUT THIS IS SOMETHING THAT WILL
HAVE TO BE WATCHED CLOSELY, AND CAN BE BETTER HANDLED WITH A SHORT
FUSED PRODUCT. HIGHER CONFIDENCE IN 40+ MPH WIND GUSTS WITH THE STOUT
LOW LEVEL COLD ADVECTION BEHIND THE FRONT, AS 850 MB TEMPS CRASH
TO -16 C AROUND 12Z FRIDAY. 700 MB COLD POOL REACHES LAKE HURON BY
15Z FRIDAY ALREADY, THUS SUBSIDENCE AND LOWERING INVERSION HEIGHTS
SHOULD ATTEMPT TO LIMIT SNOW SHOWER INTENSITY FROM THE WESTERLY BANDS
OFF LAKE MICHIGAN. WILL CONTINUE TO ADVERTISE HIGH SCATTERED- LOW
NUMEROUS COVERAGE OF SNOW SHOWERS WITH ACCUMULATIONS OF A DUSTING UP
TO 1 INCH IN THE STRONGEST ACTIVITY. SFC-925-850 MB TEMP/DEW PT
GRADIENT REALLY TIGHTENS UP 9-12Z TIME FRAME AND IS POSITIONED TO
PROVIDE THE FOCUS IN THE I-69/M-59 CORRIDORS. THERE STILL LOOKS TO BE
A LOW CHANCE/ISOLATED SNOW SQUALL WITH MODEST CAPE BRIEFLY
INTERSECTING THE DGZ LATE MORNING/MIDDAY WITH SURFACE TEMPS IN LOW TO
MID 20S.
THE FAST TRACKING PACIFIC STORMS LOOK TO CONTINUE TO TRACK ALONG THE
CANADIAN/UNITED STATES BORDER THROUGH THE WEEKEND INTO EARLY NEXT
WEEK. ONE COLD FRONT TO ROLL THROUGH SATURDAY, WITH LARGE AREA OF
HIGH PRESSURE TRACKING THROUGH SUNDAY-MONDAY MORNING, UNDERNEATH
SOME GOOD UPPER LEVEL CONFLUENT FLOW. WARM ADVECTION/ELEVATED WARM
FRONT LOOKS TO BE ARRIVING LATE MONDAY/MONDAY NIGHT, BUT BEST
MOISTURE/FORCING LOOKS TO BE OVER THE WESTERN GREAT LAKES REGION.
THE NEXT COLD FRONT THEN PROGGED FOR TUESDAY ALREADY. BOTTOM LINE,
PRECIP CHANCES LOOK LOW FOR THE EXTENDED, AND ANY AMOUNTS WILL BE
LIGHT. TEMPERATURES ARE ALSO BORDERLINE/MARGINALLY COLD, THUS
RAIN/SNOW LINES WILL HAVE TO BE WORKED OUT IF PRECIP DOES IN-FACT
OCCUR. OUTGOING NBM POPS ARE SLIGHT CHANCE AT BEST.
MARINE...
SOUTHERLY FLOW WILL CONTINUE TO STRENGTHEN THROUGH THE DAY, PEAKING
LATE THIS AFTERNOON AS THE LOW LEVEL WIND MAX ARRIVES JUST AHEAD OF
A COLD FRONT. STRONGEST WINDS (70+ KNOT LOW LEVEL JET) STAY
ELEVATED, BUT SHALLOW MIXING WILL STILL BE SUFFICIENT TO BRING GALE
FORCE GUSTS (35-40 KNOTS) TO THE SURFACE ACROSS THE OPEN WATERS.
COLDER WATER TEMPS AND ICE COVER MAINTAIN MORE STABILITY TOWARD THE
SHORELINE AND CAP GUSTS AROUND 30 KNOTS. GALE WARNINGS ARE THUS IN
EFFECT FOR THE OPEN WATERS WITH SMALL CRAFT ADVISORIES ALONG THE
NEARSHORE, UNLESS OBSERVATIONS WARRANT AN UPGRADE. THE FRONT WILL BE
DEFINED BY A BAND OF RAIN THAT TRANSITIONS TO SNOW ON ITS BACK EDGE,
AS WELL AS A QUICK POP IN WIND GUSTS THIS EVENING. THIS WILL BE
FOLLOWED BY A BRIEF LULL IN WINDS LATE TONIGHT, BUT A QUICK RETURN
TO GALE FORCE GUSTS BY FRIDAY MORNING AMIDST STRONG COLD ADVECTION.
THE COLDER AIRMASS IS MORE FAVORABLE FOR GALES TO EXTEND INTO THE
NEARSHORE ZONES FRIDAY, WITH A GALE WATCH IN EFFECT LATE THU NIGHT-
FRI FOR THE LAKE HURON NEARSHORE. WINDS FRIDAY VEER FROM SW TO NW,
SUSTAINED AROUND 30-35 KNOTS, WHICH WILL SUPPORT LAKE EFFECT SNOW
SHOWERS. COMBINATION OF LAKE EFFECT SNOW AND GUSTY WINDS WILL
GENERATE SNOW SQUALLS FRIDAY BEFORE WINDS SUBSIDE FRIDAY NIGHT AS
HIGH PRESSURE FILLS IN. ANOTHER LOW ARRIVES SATURDAY NIGHT, WHICH
WILL BE THE NEXT OPPORTUNITY FOR HEADLINES.
HYDROLOGY...
YESTERDAY'S AFTERNOON SUNSHINE AND TEMPERATURES IN THE LOW TO MID
40S LEAD TO DECENT SNOW MELT. EVEN MORE AGGRESSIVE SNOW MELT WILL
OCCUR THIS AFTERNOON AND EVENING WITH RAIN AND TEMPS PUSHING 50
DEGREES. EVEN SO, WITH EXPECTED BASIN AVERAGE RAINFALL TOTALS AT OR
SLIGHTLY BETTER THAN HALF AN INCH, NO FLOODING IS ANTICIPATED. THERE
WILL HOWEVER, BE PONDING OF WATER ON LOW LYING AREAS AND ROADS.
RISES ON AREA RIVERS WILL OCCUR, BUT WELL BELOW BANKFULL.
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 TONIGHT FOR LHZ421-441>443.
GALE WATCH FROM LATE TONIGHT THROUGH FRIDAY EVENING FOR LHZ421-422-
441>443.
LOW WATER ADVISORY UNTIL 7 PM EST FRIDAY FOR LHZ422.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR LHZ422.
GALE WARNING UNTIL 7 PM EST FRIDAY FOR LHZ463-464.
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR LEZ444.
LOW WATER ADVISORY FROM 4 AM TO 4 PM EST FRIDAY FOR LEZ444.
AVIATION.....CB
DISCUSSION...SF
MARINE.......MV
HYDROLOGY....SF
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AT WWW.WEATHER.GOV/DETROIT.
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