428
FXUS63 KDTX 182033
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
333 PM EST THU DEC 18 2025
KEY MESSAGES
- WIDESPREAD RAINFALL THIS EVENING WITH AROUND A HALF INCH OF
RAINFALL ACCUMULATION.
- GUSTY WINDS OF 30-40 MPH TONIGHT THROUGH FRIDAY AFTERNOON.
- THERE IS THE POTENTIAL FOR ANY MOISTURE ON ROADWAYS TO FLASH
FREEZE TONIGHT 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.
DISCUSSION
IMPRESSIVE SYSTEM TRACKING ACROSS THE CENTRAL CONUS TODAY THAT WILL
IMPACT THE GREAT LAKES THIS EVENING THROUGH FRIDAY. OCCLUDED SURFACE
LOW AT 987MB OVER THE WESTERN UP WILL CURL UP TO THE NE INTO NORTHERN
QUEBEC BY FRIDAY MORNING AS THE DEEP AND ELONGATED MID/UPPER LEVEL
TROUGH EXTENDING DOWN INTO THE SOUTHERN STATES TILTS FROM NEUTRAL TO
NEGATIVE TILT AND SLINGS THE LOW NORTHEASTWARD. VERY DYNAMIC SYSTEM
WITH 160 KNOT UPPER LEVEL JET FEEDING INTO IT AND A 70 KNOT LOW
LEVEL JET SURGING DUE NORTH AHEAD OF THE COLD FRONT. LUCKILY STABLE
CONDITIONS AHEAD OF THE OCCLUDED FRONT ARE PREVENTING THE LOW LEVEL
JET FLOW FROM MIXING DOWN, BUT WIND GUSTS THIS AFTERNOON/EVENING
WILL STILL RESIDE MAINLY IN THE 20-30 KNOT RANGE FOR THE MOST PART.
BEST CHANCE OF STRONGER WINDS WILL ACCOMPANY A THUNDERLESS LINE OF
CONVECTION ALONG THE COLD FRONT THIS EVENING MAINLY BETWEEN 00-04Z
AS DEEPER MIXING ALONG THE FRONT MAY TAP INTO THE STRONG WINDS ALOFT
BEFORE THE LLJ DEPART EAST. DUE TO LIKELY SHORT DURATION AND
FRONTAL/CONVECTIVE NATURE OF THE GUSTS, WILL ASSESS THE OBS AS THE
FRONT MARCHES EAST AND HANDLE THE HIGHER GUSTS WITH AN SPS AS
NEEDED.
PRECIP HAS BECOME MORE WIDESPREAD SINCE 19Z AFTER HOLDING MAINLY
ACROSS SAGINAW THROUGH THE EARLY PART OF THE DAY. THIS MORE
DRIVEN BATCH OF SHOWERS WILL PUSH THROUGH EARLY THIS
EVENING PRODUCING AROUND 0.1-0.2 OF QPF. THE CONVECTIVELY DRIVEN
SHOWERS ALONE THE FRONT TONIGHT SHOULD BE RESPONSIBLE FOR AN
ADDITIONAL 0.2-0.3 OF QPF. COMBINED WITH RECENT SNOW MELT, WHICH
WILL CONTINUE UNTIL THE FRONTAL PASSAGE, WILL LEAD TO SOME RISES IN
LOCAL RIVERS AND PONDING ON ROADS BUT SHOULDN'T RESULT IN FLOODING
CONCERNS.
BIG CHANGES TONIGHT AS AGGRESSIVE COLD ADVECTION KICKS IN THE WAKE
OF THE COLD FRONT. 850MB THERMAL TROUGH DIVING INTO THE PLAINS IS
CURRENTLY AROUND -20C WHILE WE SIT AT 6C OVER SE MI. WITH SOME
AIRMASS MODIFICATION TO OCCUR, WE'LL STILL SEE 850MB TEMPS DROP TO
AROUND 0C BY 06Z AND -13C BY 12Z FRIDAY MORNING. THE STARKLY COLDER
AIRMASS WILL EXCITE A PERIOD OF LAKE EFFECT SNOW SHOWERS TONIGHT
INTO FRIDAY. INITIALLY, THE RAPID RISE IN MIXED LAYER DEPTH AND
RESIDUAL MOISTURE COMBINED WITH LAKE ENHANCEMENT WILL LEAD TO A
BURST OF LIGHT SNOW SHOWERS OVERNIGHT BUT MIXED LEVELS ONLY AROUND
5KFT WILL LIMIT HIGHER SNOWFALL TOTALS FROM REACHING VERY FAR ACROSS
LOWER MI. ADDITIONAL IT LOOKS LIKE A MULTI-BAND SET UP WITH THE
STRONG WESTERLY WINDS AS OPPOSED TO ONE STRONG CONVERGENT BAND
SETTING UP. ONE THING TO WATCH WILL BE ACROSS MID MI AS THE UPPER
LOW CENTER WITHIN THE TRAILING TROUGH AXIS DROPS INTO NORTHERN-MID
MI WHICH COULD BRING A STRONGER BAND OF CONVERGENCE INTO THE SAGINAW
VALLEY AND NORTHERN THUMB WITH BRIEFLY HIGHER RATES. DRY AIR
ADVECTION FRIDAY WILL LEAD TO DECREASING CHANCES FOR SNOW SHOWERS
THROUGH THE LATE MORNING AND AFTERNOON, LIKELY WITH MAINLY FLURRIES
BY NOON AS RH FIELDS SHOW THE MOISTURE FIELD DISCONNECTING FROM LAKE
MI EARLY IN THE DAY. HIGH TEMPS WILL HOLD IN THE UPPER 20S FRIDAY
WITH WIND CHILLS HOLDING AROUND 10F AS STRONG WESTERLY WINDS
CONTINUE THROUGH THE DAY. MODEL SOUNDINGS SHOW A DEEP LAYER OF WINDS
AROUND 30-35 KNOTS THROUGH THE MIXED LAYER SO CONFIDENCE IS PRETTY
HIGH IN GUSTS OF 30-40 MPH THROUGH MUCH OF THE DAY. VERY LITTLE
SUPPORT FOR WINDS OVER 45 MPH SO NOT CONSIDERING ANY WIND ADVISORIES
AT THIS TIME.
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 WHICH WILL RESULT IN LIGHT SNOW OR
RAIN/SNOW MIX. NEXT STRONGER LOW IS FORECAST TO ARRIVE MONDAY NIGHT
INTO TUESDAY AND CURRENTLY IS TRACKING NORTH OF THE AREA LEADING TO
WARMER AIR AND PTYPES ACROSS SOUTHERN MI. TEMPERATURES WILL BE
BOUNCING AROUND THROUGH THE WEEK AS WE REMAIN NEAR THE BAROCLINIC
ZONE WITH SYSTEMS PASSING NEAR AND AROUND THE REGION.
MARINE
GALE WARNINGS ARE IN EFFECT FOR ALL OF LAKE HURON THROUGH FRIDAY AS
STRONG LOW PRESSURE AND A COLD FRONT IMPACT THE GREAT LAKES. THE
WARM AIR IN PLACE HAS KEPT THE NEARSHORE WATERS STABLE (GUSTS AOB 30
KNOTS), WHILE SHIP OBSERVATIONS HAVE REPORTED WINDS OF 30-35 KNOTS
ACROSS THE OPEN WATERS. THE FRONT IS JUST NOW ENTERING LAKE MICHIGAN
AND IS MOVING EAST AT ABOUT 30 KNOTS, BRINGING IT THROUGH THE LOCAL
WATERS BETWEEN 01-05Z (8P-12A EST). THE FRONT IS MARKED BY A NARROW
BAND OF RAIN AND AN ABRUPT WIND SHIFT FROM S TO W/NW, WITH THE
SHARPEST WIND SHIFT OCCURRING OVER LAKE ERIE AND A MORE MUTED SHIFT
FOR LAKE HURON. A RAPID DROP IN TEMPERATURES IS ALSO EXPECTED,
TRANSITIONING RAIN TO SNOW AS LAKE MICHIGAN SNOW SHOWERS DEVELOP.
THE SURGE OF COLD AIR WILL BE MORE FAVORABLE FOR MIXING, WITH THE
GALE WARNING EXPANDING TO THE LAKE HURON NEARSHORE ZONES AT MIDNIGHT
ALTHOUGH AN EARLIER UPGRADE REMAINS POSSIBLE DEPENDING ON THE
FRONTAL TIMING. SNOW SQUALLS AND W/NW FLOW GUSTING TO GALES WILL
CHARACTERIZE THE POST-FRONTAL AIRMASS ON FRIDAY BEFORE HIGH PRESSURE
EASES THE GRADIENT FRIDAY NIGHT AND HEADLINES DROP OFF. QUIET MARINE
WEATHER LASTS THROUGH DAYTIME SATURDAY, BUT THE NEXT LOW RAMPS WINDS
BACK UP TOWARD GALES SATURDAY NIGHT-SUNDAY. GIVEN THE COMPLEX
HEADLINES ATTM, WILL HOLD OFF ON ANY ADDITIONAL HEADLINES FOR THE
SAT NIGHT SYSTEM.
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.
PREV DISCUSSION
ISSUED AT 1247 PM EST THU DEC 18 2025
AVIATION...
MOISTURE ADVECTION WILL CONTINUE THROUGH THE AFTERNOON AHEAD OF A
COLD FRONT WHICH WILL RESULT IN SPORADIC RAIN SHOWERS ALONG WITH THE
EVENTUAL QUICK DROP FROM VFR TO MVFR CIGS. THE BETTER MOISTURE
CONVERGENCE AND THUS MORE PROLIFIC SHOWER ACTIVITY WILL HOLD ACROSS
KMBS THROUGH THE EARLY AFTERNOON WITH BETTER COVERAGE EXPANDING
DOWNSTREAM AS A BETTER MOISTURE PLUME FILLS IN ACROSS SE MI. A
STRONG COLD FRONT WILL THEN EXPAND ACROSS THE TERMINALS FROM
NORTHWEST TO SOUTHEAST BETWEEN ROUGHLY 01Z TO 04Z. THIS FRONT WILL
LIKELY RESULT IN A THUNDERLESS LINE OF STRONG SHOWERS CAPABLE OF
BRIEFLY PRODUCING WIND GUSTS TO OR IN EXCESS OF 35 KNOTS, WHILE WIND
DIRECTION RAPIDLY VEERS FROM SOUTH TO WEST. TEMPERATURES QUICKLY
DROP BELOW FREEZING BEHIND THIS FRONT, TRANSITIONING ANY LINGERING
RAIN SHOWERS TO SNOW. MVFR TO IFR CIGS ARE EXPECTED WITHIN THE
VICINITY OF AND IN THE WAKE OF THIS FRONTAL BOUNDARY. THERE MAY BE A
BRIEF LULL IN PRECIPITATION IMMEDIATELY BEHIND THE FRONT, HOWEVER,
COLD AIR ADVECTION WILL LIKELY PRODUCE ISOLATED TO SCATTERED SNOW
SHOWERS SEVERAL HOURS LATER LEADING INTO THE LATE MORNING HOURS
WHERE SPORADIC SNOW ACCUMULATIONS OF AN INCH OR LESS ARE POSSIBLE.
CONDITIONS REMAIN BREEZY WITH GUSTS 25 TO 30 KNOTS TONIGHT AND
OVERNIGHT.
FOR DTW...ARRIVAL OF MVFR CIGS REMAIN LIKELY AROUND 21Z, AHEAD OF A
STRONG COLD FRONT. THE COLD FRONT WILL THEN BRING A LINE OF STRONG
SHOWERS BETWEEN 02-04Z CAPABLE OF PRODUCE GUSTS AROUND 35 KNOTS,
ALONG WITH A RAPID CHANGE IN WIND DIRECTION FROM SOUTH TO WEST.
AFTER THE PASSAGE OF THE FRONT, TEMPERATURES QUICKLY DROP BELOW
FREEZING, BRINGING INCREASING CHANCE FOR SNOW SHOWER ACTIVITY
THROUGH THE MORNING.
DTW THRESHOLD PROBABILITIES...
* MODERATE IN CEILINGS AOB 5000 FEET THIS AFTERNOON. HIGH BY THE
EARLY EVENING THROUGH TOMORROW.
* HIGH IN PRECIPITATION TYPE BEING ALL RAIN TODAY. HIGH CONFIDENCE
IN SNOW AS A PRECIPITATION TYPE AFTER 06Z FRIDAY.
* MEDIUM IN CROSSWINDS THRESHOLDS BEING EXCEEDED AFTER 08Z FRIDAY.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...GALE WARNING UNTIL 7 PM EST FRIDAY FOR LHZ361>363-462>464.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR LHZ421-422-
441>443.
GALE WARNING FROM MIDNIGHT TONIGHT TO 7 PM EST FRIDAY FOR LHZ421-
422-441>443.
LOW WATER ADVISORY UNTIL 7 PM EST FRIDAY FOR LHZ422.
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.
DISCUSSION...DRK
MARINE.......MV
HYDROLOGY....SF
AVIATION.....AM
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