518
FXUS63 KDTX 171749
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1249 PM EST WED DEC 17 2025
KEY MESSAGES
- MILD WITH HIGH TEMPS IN THE UPPER 30 TO LOWER 40S TODAY AND 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
A RIDGE OF HIGH PRESSURE PASSING TO THE SOUTH MAINTAINS A LOW-LEVEL
INVERSION THAT CONTINUES TO LOWER SLIGHTLY THIS AFTERNOON,
MAINTAINING POTENTIAL FOR MVFR CEILINGS AT TIMES. THINKING THE
STRATUS WILL BEGIN TO SCATTER AND TREND TO VFR BY THIS EVENING.
WESTERLY WIND WILL BACK TO SOUTHERLY TONIGHT AND STRENGTHEN
CONSIDERABLY OVERNIGHT IN ADVANCE OF A STRONG LOW PRESSURE SYSTEM
TRACKING IN FROM THE WEST ON THURSDAY. A CORE OF 50+ KT FLOW WITHIN
THE LOWEST 1.5 TO 2 KFT WILL ARRIVE EARLY THURSDAY MORNING, LEADING
TO LLWS CONCERNS BEFORE THE SURFACE LAYER WIND INCREASES AND
MITIGATES THE SHEAR. THIS SPEED MAX ALOFT PEAKS DAYTIME THURSDAY AT
60+ KT, WITH SURFACE GUSTS EXCEEDING 30 KT. WIDESPREAD RAIN WILL
ARRIVE FROM THE SOUTH AND WEST DURING THE MORNING, WITH MVFR THEN
IFR CONDITIONS EXPECTED FIRST IN THE SAGINAW VALLEY BY AROUND NOON,
THEN SPREADING ACROSS THE REST OF THE AREA LATER IN THE DAY.
FOR DTW...CEILING TRENDS THIS AFTERNOON CARRY A HIGH AMOUNT OF
UNCERTAINTY. LLWS WILL BECOME LIKELY AFTER AROUND 08Z AND MAY
PERSIST LONGER INTO THE MORNING DEPENDING ON HOW WINDY THE SURFACE
LAYER BECOMES. HIGH CONFIDENCE IN ALL RAIN THROUGH 00Z FRI.
DTW THRESHOLD PROBABILITIES...
* MODERATE IN CEILINGS AOB 5000 FEET TODAY. HIGH AFTER 10Z THURSDAY
MORNING.
PREV DISCUSSION
ISSUED AT 247 AM EST WED DEC 17 2025
DISCUSSION...
TEMPERATURES FINALLY CLIMBED ABOVE THE FREEZING MARK YESTERDAY, YET
DETROIT'S MAX OF 34 DEGREES WAS STILL 3 DEGREES BELOW NORMAL.
TEMPERATURES HAVE BEEN BELOW NORMAL EVERY SINGLE DAY THIS MONTH. IT
WILL BE EVEN WARMER TODAY, WITH HIGH POTENTIAL TO EXCEED 40 DEGREES
IF LOW CLOUDS FAIL TO MATERIALIZE OR ARE SLOWER TO DEVELOP THIS
MORNING. BEST CHANCE OF THIS OCCURING WOULD BE TOWARD THE SOUTHERN
MICHIGAN BORDER, AS LOW LEVEL WINDS SHIFTING TO THE WEST WILL ALLOW
FOR SOME MOISTURE FLUX FROM LAKE MICHIGAN, WHICH LEADS TO HIGHER
CONFIDENCE OVER THE NORTHERN HALF OF THE CWA BEING LOCKED INTO
CLOUDS WITH THE FRONTAL PASSAGE. ON THE FLIP SIDE, LOCATIONS TOWARD
THE SOUTHERN MICHIGAN BORDER LOOK TO BE EXPERIENCING HIGH BASED
SPRINKLES OVER THE NEXT SEVERAL HOURS.
THURSDAY WILL BE THE WARMEST DAY OF THE WEEK WITH DEEP SOUTHERLY
FLOW AHEAD OF OUR DEEPENING STORM SYSTEM OVER THE MIDWEST, AS 165+
KNOT JET AT 250 MB DIVES SOUTHEAST FROM THE NORTHERN ROCKIES. AS A
RESULT, 500 MB TROUGH AXIS EVEN SEEN GOING NEGATIVE TILTED AS IT
MOVES THROUGH THE GREAT LAKES REGION/OHIO VALLEY THURSDAY
EVENING/NIGHT. WITH 925 MB TEMPS PROGGED TO BE AOA 4 C DURING MIDDAY
THURSDAY, THE POTENTIAL IT CERTAINLY THERE FOR TEMPERATURES TO REACH
50 DEGREES, DEPENDING ON THE ARRIVAL TIME OF RAIN SHOWERS. BECAUSE
OF THIS, SOUTHEASTERN AREAS OF THE CWA LOOK TO BE THE WARMEST.
PRETTY GOOD AGREEMENT AMONGST THE MODELS WITH NEAR A HALF INCH OF
QPF, AS THE EURO ENSEMBLES INDICATING JUST A 30-40 PERCENT CHANCE OF
EXCEEDING HALF AN INCH ACROSS SOUTHERN HALF OF THE CWA.
FRONTAL PASSAGE LOOKS TO BE AROUND MIDNIGHT, WITH EXCELLENT LOW COLD
ADVECTION AS 850 MB TEMPS PLUMMET TO -16 C BY 12Z FRIDAY. WITH 40+
KNOTS OF FLOW AT 925 MB, OCCASIONAL WIND GUSTS OF 30-40 MPH SHOULD BE
OBTAINABLE THURSDAY THROUGH FRIDAY MORNING. STEEP LOW LEVEL LAPSE
RATES WITH INVERSION HEIGHT AROUND 4 KFT, WHICH IS RATHER SHALLOW.
HOWEVER, WHAT LITTLE CAPE THAT IS GENERATED DOES RESIDE IN THE DGZ.
THUS, THERE IS A LOW CHANCE OF SNOW SQUALLS, AS MULTIPLE WESTERLY
BANDS LOOK TO BE COMING OFF LAKE MICHIGAN. AT THE VERY LEAST,
SCATTERED TO NUMEROUS LIGHT SNOW SHOWERS ARE EXPECTED. WITH
ACCUMULATIONS OF UP TO AN INCH.
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, BUT BEST MOISTURE/FORCING LOOKS TO
BE OVER THE WESTERN GREAT LAKES REGION/NORTHERN LOWER MICHIGAN. THE
NEXT COLD FRONT THEN PROGGED FOR TUESDAY ALREADY.
MARINE...
COLD FRONT TIED TO THE JAMES BAY CLIPS THE REGION EARLY THIS MORNING
USHERING IN RENEWED NORTHWEST FLOW. 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 OVER THE SECOND OF TODAY AS THE NORTHERN EDGE
OF OHIO VALLEY HIGH PRESSURE DRIFTS OVERHEAD. ANOTHER STRONG LOW
THEN ARRIVES OVER THE NORTHERN GREAT LAKES THURSDAY LEADING TO
STRENGTHENING SOUTHERLY FLOW BY LATE TONIGHT-EARLY THURSDAY. SIMILAR
TO TUESDAY'S SYSTEM, WARM ADVECTION LIMITS OVERLAKE INSTABILITY AND
SUBSEQUENT MIXING DOWN OF 50-60KT WINDS ALOFT. THIS HOWEVER LOOKS TO
ONLY CAP MAX GUST POTENTIAL AT AROUND 40KTS WITH HIGH PROBABILITIES
TO SEE FREQUENT GUSTS TO MID/UPPER 30KTS DUE TO A TIGHTER GRADIENT
GIVEN THE TRACK OVER LAKE SUPERIOR. THERE IS SIGNAL FOR A BRIEF LULL
IN GALES EARLY THURSDAY NIGHT WHEN THE LEAD COLD/OCCLUDED FRONT
CROSSES THE REGION. A SECONDARY ARCTIC COLD FRONT IS QUICK TO FOLLOW
HOWEVER, CROSSING LATE THURSDAY NIGHT/EARLY FRIDAY, SETTING UP
STRONG W TURNING NW COLD ADVECTION SUPPORTING GUSTS TO GALES FOR
MUCH OF DAYTIME FRIDAY.
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...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LHZ421-441.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....TF
DISCUSSION...SF
MARINE.......KDK
HYDROLOGY....SF
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