836
FXUS63 KDTX 162242
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
542 PM EST TUE DEC 16 2025
KEY MESSAGES
- MILD WITH TEMPS IN THE MID TO UPPER 30S WEDNESDAY AND 40S ON
THURSDAY.
- WIDESPREAD RAINFALL IS EXPECTED ON THURSDAY, FOLLOWED BY LIGHT
SNOW OVERNIGHT INTO FRIDAY MORNING. GUSTY WINDS TO 30-35 MPH WILL BE
POSSIBLE THURSDAY AND FRIDAY.
- THERE IS THE POTENTIAL FOR ANY MOISTURE ON ROADWAYS TO FLASH
FREEZE THURSDAY NIGHT AS ARCTIC AIR MOVES BACK INTO THE REGION.
AVIATION
THE ONGOING INCREASE IN THE LOW LEVEL SOUTHWEST FLOW WILL LAST INTO
THE NIGHT IN ADVANCE OF A WEAK COLD FRONT. SLIGHT NOCTURNAL COOLING
IN THE BOUNDARY LAYER WILL KEEP SURFACE WIND SPEEDS BELOW 15 KNOTS
WHILE A CORE OF 40 TO 50 KNOT WINDS DEVELOP ATOP THE SHALLOW NEAR
SURFACE STABLE LAYER. THESE FACTORS REMAIN SUPPORTIVE OF THE MENTION
OF LOW LEVEL WIND SHEAR IN THE TAFS. WHILE LOW LEVEL MOISTURE WILL
BE LIMITED, AVAILABLE GUIDANCE INDICATES AN EXPANSION OF LOW CLOUDS
(MVFR BASED) ALONG AND WITHIN THE SHALLOW POST FRONTAL COLD AIR
ADVECTION LATE TONIGHT/EARLY WED MORNING. THE POST FRONTAL INVERSION
WILL REMAIN QUITE DEEP INTO WED AFTERNOON, LIKELY LOCKING THE LOW
CLOUDS IN PLACE THROUGH A GOOD PORTION OF THE DAY WEDNESDAY.
FOR DTW...THE LATEST MODEL GUIDANCE INDICATE A RAPID INCREASE IN THE
1500-2000 FT LEVEL WINDS IN THE 00Z TO 03Z TIME FRAME. THIS WILL
WARRANT BUMPING THE START OF THE LLWS UP A COUPLE HOURS TO 03Z.
DTW THRESHOLD PROBABILITIES...
* LOW IN CEILINGS AOB 5000 FEET TONIGHT. MODERATE ON WEDNESDAY.
PREV DISCUSSION
ISSUED AT 338 PM EST TUE DEC 16 2025
DISCUSSION...
LOW AMPLITUDE RIDGING AND A LULL IN JET FORCING ALOFT MAINTAINS
BENIGN CONDITIONS THE REST OF THE AFTERNOON WITH PLENTY OF DRY AIR
IN PLACE BELOW 10 KFT AGL. LOW PRESSURE TRACKING ACROSS NORTHERN
ONTARIO WILL SEND A TRAILING COLD FRONT ACROSS THE REGION EARLY
WEDNESDAY. LOW LEVEL SOUTHWEST WIND WILL INCREASE TONIGHT AHEAD OF
THIS LOW AS THE LLJ PIVOTS ACROSS THE NORTHERN GREAT LAKES, WITH LOW
LEVEL MOISTURE POOLING OUT AHEAD OF THE FRONT EARLY WEDNESDAY
MORNING. MODEL SOUNDINGS SHOW A PERIOD OF SATURATION OCCURING BELOW
3000 FT AFTER MIDNIGHT - THIS CARRIES THE POTENTIAL TO PRODUCE SOME
PATCHY LIGHT DRIZZLE OR FREEZING DRIZZLE THROUGH MID MORNING AS THE
FRONT MOVES THROUGH. THE SHALLOW NATURE OF THE MOISTURE OFFERS VERY
LOW CONFIDENCE IN OCCURRENCE, BUT WIND SHEAR ATOP THE BOUNDARY LAYER
AND/OR THE FRONT MAY BE SUFFICIENT TO GENERATE DRIZZLE. MODEL SIGNAL
REMAINS OVERWHELMING DRY THROUGH FROPA SO WILL KEEP THE FORECAST
DRY. LOCAL SREF WEIGHTED PROBABILISTIC GUIDANCE PEAKS AT A 10%
CHANCE FOR FREEZING DRIZZLE BETWEEN 2 AND 8 AM. TEMPERATURES WILL BE
RISING OVERNIGHT INTO THE MID 30S BY WEDNESDAY MORNING, EVENTUALLY
PEAKING IN THE UPPER 30S IN THE AFTERNOON.
A PASSING RIDGE OFFERS CONTINUED BENIGN CONDITIONS THROUGH THE DAY
WEDNESDAY. A STRONG PACIFIC JET STREAK WILL THEN DRIVE MORE ACTIVE
CONDITIONS FROM THE NORTHERN ROCKIES AND UPPER MIDWEST INTO THE
GREAT LAKES BY THURSDAY. THE TROUGH AT THE NOSE OF THIS JET WILL
DEEPEN AND TAKE ON A SLIGHT NEGATIVE TILT AS IT CROSSES THE GREAT
LAKES FRIDAY MORNING. THIS OFFERS VERY HIGH CONFIDENCE IN WIDESPREAD
SYNOPTIC ASCENT AND PRECIPITATION THURSDAY, AS WELL AS A SURFACE LOW
TRACK ACROSS THE NORTHERN GREAT LAKES. THE WARM CONVEYOR ARRIVES
THURSDAY MORNING WITH WARM AND MOIST ADVECTION USHERING AN
INCREASING COVERAGE OF LIGHT RAIN THROUGH EARLY AFTERNOON.
TEMPERATURES WILL SIT COMFORTABLY ABOVE FREEZING FROM THE SURFACE UP
TO NEARLY 8000 FT, GIVING HIGH CONFIDENCE IN ALL RAIN THROUGH THE
DAY. THERE MAY BE A PERIOD OF MORE MODERATE RAINFALL RATES DURING
THE AFTERNOON AS FRONTAL FORCING RAMPS UP WHILE DEEP-LAYER MOISTURE
TRANSPORT PUSHES PWAT TO 0.75 TO 1.00". TOTAL LIQUID QPF IS FAVORED
TO BE ON THE ORDER OF 0.25 TO 0.60", WHICH WITH SNOW MELT MAY LEAD
TO PONDING ON ROADS THURSDAY. SOME ADDITIONAL DETAILS ARE IN THE
HYDROLOGY SECTION.
MODELS HAVE TRENDED SLIGHTLY LOWER ON WIND MAGNITUDE THURSDAY OWING
TO THE HIGH STABILITY IN THE WARM ADVECTION, BUT GUSTS TO 25-35 MPH
WILL BE POSSIBLE. TEMPERATURES WILL REACH THE 40S FOR THE FIRST TIME
SINCE NOVEMBER 26. THE NBM EVEN GIVES A 25% PROBABILITY FOR AREAS OF
MONROE COUNTY TO REACH 50 DEGREES. RAINFALL RATES WILL TAPER OFF BY
THE EVENING HOURS AS THE DRY SLOT ARRIVES. THE COLUMN COOLS WITH
SOME MELTING FLAKES POSSIBLE LATE EVENING. TEMPERATURE PROGS
CONTINUE TO DELAY THE RETURN OF FREEZING TEMPS AT THE SURFACE, WHICH
IS NOW SLATED TO OCCUR LATE EVENING TO OVERNIGHT WHICH WILL MITIGATE
RUSH HOUR TRAVEL CONCERNS BUT MAY STILL POSE A THREAT OVERNIGHT TO
REFREEZE ANY RESIDUAL MOISTURE ON ROADWAYS. A PERIOD OF LIGHT
ACCUMULATING SNOWFALL IS THEN POSSIBLE INTO EARLY FRIDAY MORNING
WITH THE BULK OF MODEL SOLUTIONS SUPPORTIVE OF A TRACE TO 0.5" TYPE
SNOWFALL MAINLY BEFORE SUNRISE. ADDITIONAL SCATTERED SNOW SHOWERS OR
FLURRIES MAY PERSIST INTO THE AFTERNOON.
AFTER BELOW NORMAL TEMPS ON FRIDAY, LOW AMPLITUDE ZONAL FLOW SETS UP
OVER THE NORTHERN CONUS WHICH WILL FAVOR GENERALLY SEASONABLE
CONDITIONS INTO NEXT WEEK. SATURDAY PRESENTS THE NEXT OPPORTUNITY
FOR LIGHT SNOW, MAINLY ACROSS THE NORTH, AS A WEAKER WAVE PASSES
THROUGH CENTRAL ONTARIO WITH LIMITED MOISTURE AVAILABLE.
MARINE...
SOUTHWEST WINDS CONTINUE TO INCREASE THROUGH THE EVENING IN RESPONSE
TO A STRONG NORTHERN ONTARIO LOW REACHING THE JAMES BAY. WHILE A
50KT LLJ IS SET TO EXPAND ACROSS THE CENTRAL GREAT LAKES BY LATE
EVENING, STRONG WARM ADVECTION LIMITS THE DEGREE OF MIXING OVER THE
COLDER LAKE WATERS WHICH IS STILL EXPECTED TO PREVENT GUSTS TO
STRONG GALES (>40KTS). THAT SAID, GRADIENT AND FETCH DIRECTION STILL
SUPPORTS HIGH POTENTIAL FOR FREQUENT GUSTS TO 35-40KTS ACROSS THE
SAGINAW BAY AND CENTRAL PORTIONS OF LAKE HURON THROUGH THE FIRST
HALF OF TONIGHT. STRONG SOUTHWESTERLY WINDS WILL ALSO SUPPORT
UNSTABLE ICE CONDITIONS IN THE INNER SAGINAW BAY WITH POTENTIAL FOR
FLOES TO BREAK OFF AND DRIFT INTO THE OPEN WATERS. COLD FRONT THEN
GLANCES THE REGION LATE TONIGHT-EARLY WEDNESDAY MORNING USHERING IN
RENEWED NORTHWEST COLD ADVECTION. THE GLANCING SHOT OF COLD
ADVECTION, WITH THE CORE REMAINING NORTH OF LAKE HURON, LEADS TO A
MORE MARGINAL-TYPE GALE EVENT FOR NORTHERN LAKE HURON WITH A 3-5HR
PERIOD WHERE GUSTS WILL BE CAPABLE OF PEAKING IN THE 34-36KT RANGE.
WINDS QUICKLY WEAKEN WEDNESDAY AS THE NORTHERN EDGE OF OHIO VALLEY
HIGH PRESSURE DRIFTS OVERHEAD. ANOTHER STRONG LOW THEN ARRIVES OVER
THE NORTHERN GREAT LAKES THURSDAY. THIS SYSTEM CARRIES A SOLID
LIKELIHOOD OF GALES GIVEN THE CLOSER TRACK (COMPARED TO TODAY'S LOW)
AND DEEPER CENTRAL PRESSURE.
HYDROLOGY...
MILDER TEMPERATURES BRING SNOW MELT ACROSS THE AREA LATER THIS WEEK
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. RAINFALL TOTALS RANGING BETWEEN 0.25 AND
0.60 INCHES WILL BE MOST LIKELY THURSDAY, 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...SMALL CRAFT ADVISORY UNTIL NOON EST WEDNESDAY FOR LHZ442-443.
GALE WARNING FROM 2 AM TO NOON EST WEDNESDAY FOR LHZ361.
GALE WARNING UNTIL NOON EST WEDNESDAY FOR LHZ362.
GALE WARNING UNTIL 6 AM EST WEDNESDAY FOR LHZ363-421-422-441-462.
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL NOON EST WEDNESDAY FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL NOON EST WEDNESDAY FOR LEZ444.
AVIATION.....SC
DISCUSSION...TF
MARINE.......KDK
HYDROLOGY....TF
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AT WWW.WEATHER.GOV/DETROIT.
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