906  
FXUS63 KDTX 152049  
AFDDTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI  
349 PM EST MON DEC 15 2025  
   
KEY MESSAGES  
 
- A WARMUP IS FORECAST FOR THE MIDDLE OF THE WEEK WITH TEMPERATURES  
IN THE MID TO UPPER 30S WEDNESDAY AND 40S ON THURSDAY.  
 
- A STRONG STORM SYSTEM IS FORECAST TO IMPACT THE GREAT LAKES REGION  
LATE THIS WEEK. MUCH OF THE PRECIPITATION IS EXPECTED TO FALL IN  
THE FORM OF RAIN ON THURSDAY, TRANSITIONING TO SNOW IN SOME AREAS  
FRIDAY. GUSTY WINDS WILL ACCOMPANY THIS SYSTEM.  
 
- THERE IS THE POTENTIAL FOR ANY MOISTURE ON ROADWAYS TO FLASH FREEZE  
THURSDAY EVENING/NIGHT AS ARCTIC AIR MOVES BACK INTO THE REGION.  
 
 
   
DISCUSSION  
 
HEIGHT RISES COMMENCING THIS EVENING MARK THE DEPARTURE OF UPPER  
TROUGHING AND A PIVOT TO A ZONAL FLOW PATTERN THROUGH MID-WEEK. AT  
THE SURFACE, HIGH PRESSURE WILL REMAIN RELATIVELY STEADY ACROSS THE  
SE CONUS WITH SOUTHWEST RETURN FLOW TARGETING THE GREAT LAKES. THIS  
ALLOWS FOR THE PERVASIVE ARCTIC AIR MASS TO DISLODGE FROM THE REGION  
AND ALLOW FOR A WARMING TREND THROUGH THURSDAY. GUSTY WIND THIS  
AFTERNOON WILL SUBSIDE HEADING INTO TONIGHT WHILE 925-850MB FLOW  
VEERS TO WESTERLY AND ADVECTS LAKE MICHIGAN CLOUD ACROSS THE AREA.  
IF ENOUGH SUPERSATURATION IS MAINTAINED ACROSS THE STATE, SOME  
FLURRIES WILL BE POSSIBLE GIVEN THE DGZ PLACEMENT IN THE BOUNDARY  
LAYER. MOST GUIDANCE IS LEAN WITH THE MOISTURE SUGGESTING MAINLY  
JUST BROKEN CLOUD COVER. THE CLOUD WILL DAMPEN THE DIURNAL  
TEMPERATURE RESPONSE, BUT RESIDENT ARCTIC AIR STILL ALLOWS FOR LOWS  
IN THE LOWER TEENS OVERNIGHT.  
 
STRONG WARM ADVECTION ENSUES OVERNIGHT INTO TUESDAY WITH OBSERVED  
850MB TEMPERATURE OF -11C THIS MORNING TRENDING UP TO +6 TO 7C BY  
TOMORROW EVENING. THIS INDUCES A STRONG STABLE LAYER AND THE WARMTH  
WILL NOT BE FULLY REALIZED AT THE SURFACE, BUT TEMPS SHOULD CLIMB TO  
AROUND THE FREEZING MARK FOR THE FIRST TIME SINCE LAST WEDNESDAY.  
THERE IS A POOL OF LOW-LEVEL MOISTURE PROGGED TO ARRIVE FROM THE MID-  
MISSISSIPPI VALLEY TUESDAY NIGHT WHICH MAY BRING SOME PATCHY DRIZZLE  
OR FREEZING DRIZZLE BUT CHANCES FOR THIS REMAIN BELOW 10% IN  
PROBABILISTIC DATA. GUSTY SOUTHWEST WINDS WILL ACCOMPANY A  
TIGHTENING PRESSURE GRADIENT DURING THIS PERIOD, PRODUCING A NON-  
DIURNAL TEMPERATURE RESPONSE WITH TEMPS SLOWLY CLIMBING OVERNIGHT  
INTO THE MID 30S BY WEDNESDAY MORNING.  
 
A COLD FRONT PASSES ACROSS THE AREA ON WEDNESDAY IN RESPONSE TO A  
LOW AMPLITUDE UPPER WAVE ARRIVING FROM THE MIDWEST. MOISTURE WITH  
THE FRONT WILL BE SHALLOW AND THE OVERWHELMING MODEL SIGNAL IS FOR A  
DRY FROPA. THIS WILL SEND TEMPS BACK INTO THE 20S WEDNESDAY EVENING.  
STRONG ELEVATED WARM ADVECTION FOLLOWS FROM WEDNESDAY NIGHT INTO  
THURSDAY AS A DEEP LOW EMERGES OVER THE NORTHERN ROCKIES AND TRACKS  
INTO THE UPPER MIDWEST. THE MATURE LOW WILL PASS ACROSS THE NORTHERN  
GREAT LAKES DAYTIME THURSDAY PLACING SE MI WELL WITHIN THE WARM  
CONVEYOR AND FAVORING HIGHS IN THE MID 40S. A CORRIDOR OF DEEP  
MOISTURE TRANSPORT WILL ARRIVE DURING THE MID TO LATE MORNING,  
FAVORING WIDESPREAD RAINFALL DURING THE DAY AS TEMPS IN THE LOWEST 6  
KFT SIT COMFORTABLY ABOVE FREEZING. QPF IS ADVERTISED ON THE ORDER  
OF 0.25 TO 0.50", WHICH COMBINED WITH SNOW MELT MAY BRING SOME  
PONDING ON ROADS.  
 
ENSEMBLE GUIDANCE HAS COME INTO MORE AGREEMENT FOR A 50 TO 60 KT LLJ  
OVERHEAD ON THURSDAY WHICH IS AT THE 99TH CLIMATOLOGICAL PERCENTILE.  
MUCH OF THIS MOMENTUM WILL BE LOCKED ABOVE A STRONG INVERSION  
RESULTING FROM THE WARM ADVECTION ALOFT, BUT STILL LOOKING AT A  
PERIOD OF GUSTY SOUTH WINDS TO AROUND 30 MPH DURING THE DAY. A  
STRONGER POP OF WIND IS POSSIBLE DURING THE EVENING AS THE INITIAL  
COLD FRONT/DRY SLOT ARRIVES, BUT BY THAT POINT MUCH OF THE MOMENTUM  
ALOFT WILL BE DIRECTED OVER THE EASTERN GREAT LAKES.  
 
THE STRONG WESTERLY FLOW AND COLD ADVECTION THAT FOLLOW FRONTAL  
PASSAGE SUGGEST A RAPID TEMPERATURE DROP WHICH MAY RESULT IN A FLASH  
FREEZE SCENARIO WITH ANY RESIDUAL MOISTURE ON ROADWAYS THURSDAY  
EVENING. WILL NEED TO MONITOR THIS POTENTIAL WITH REGARDS TO THE  
EVENING RUSH HOUR. AS MOISTURE WRAPS AROUND THE SYSTEM WITH SOME  
ADDED CONTRIBUTION FROM LAKE MICHIGAN, SOME LIGHT SNOW SHOWERS WILL  
BE POSSIBLE - MAINLY THROUGH EARLY FRIDAY MORNING BUT WITH POTENTIAL  
FOR ADDITIONAL STREAMERS TO ARRIVE DAYTIME FRIDAY. THE ACTIVE  
PATTERN SEES ANOTHER BOUT OF SOUTHWESTERLY WARM ADVECTION ON  
SATURDAY FOLLOWED BY ANOTHER COLD FRONT SUNDAY TIED TO A WEAKER LOW  
NORTH OF THE GREAT LAKES.  
 
 
   
MARINE  
 
SEVERAL ROUNDS OF STRONG WINDS WILL IMPACT THE CENTRAL GREAT LAKES  
THROUGH THE COURSE OF THE WEEK. THE CURRENT SMALL CRAFT CONDITIONS  
WILL FADE INTO THIS EVENING AS A WEAK SURFACE RIDGE SWEEPS BY. THE  
NEXT LOW PRESSURE SYSTEM WILL TRAVERSE ONTARIO, MUCH LIKE THE CURRENT  
ONE. THE SURFACE PRESSURE GRADIENT WILL BE A LITTLE TIGHTER,  
SUPPORTING A STRONGER SOUTHWEST FLOW WIND RESPONSE LATE TUESDAY  
AFTERNOON THROUGH TUESDAY NIGHT - ESPECIALLY ACROSS SAGINAW BAY AND  
CENTRAL PORTIONS OF LAKE HURON. GUIDANCE IS SUPPORTING SUSTAINED  
WINDS APPROACHING 30-KTS WITH PERSISTENT GALES GUSTS. ONCE THE COLD  
FRONT MOVES THROUGH EARLY WEDNESDAY, THE FOCUS FOR STRONGER WESTERLY  
WINDS WILL BE ACROSS NORTH-CENTRAL LAKE HURON. HOWEVER, THE  
CONFIDENCE IN A MEANINGFUL WINDOW OF GALE GUSTS IS NOT QUITE AS HIGH  
WEDNESDAY MORNING - THEREFORE, WILL CONTINUE THE CURRENT GALE WATCH.  
ONLY A BRIEF RESPITE BEFORE AN EVEN STRONGER SYSTEM MOVES THROUGH THE  
REGION THURSDAY AND FRIDAY - WITH A BETTER SHOT AT GALES.  
 
 
   
PREV DISCUSSION  
 
ISSUED AT 1230 PM EST MON DEC 15 2025  
 
AVIATION...  
 
BACKED FLOW TO THE SOUTHWEST WILL MAINTAIN VFR CONDITIONS ACROSS THE  
TERMINALS AS DRY AIR IS BRIEFLY ADVECTED ACROSS SE MI. FLOW WILL  
THEN VEER TO THE WEST-NORTHWEST THIS EVENING AND OVERNIGHT WHICH  
WILL PULL LAKE MOISTURE INLAND, ALLOWING THE EXPANSIVE MVFR STRATUS  
DECK OVER NORTHERN LOWER MICHIGAN TO EXPAND FROM NORTHWEST TO  
SOUTHEAST ACROSS THE TERMINALS. MVFR CIGS ARE EXPECTED TO HOLD  
THROUGH THE OVERNIGHT PERIOD, BEFORE WINDS AGAIN BACK TO THE  
SOUTHWEST, PUSHING THE STRATUS DECK OUT OF THE REGION. HIGH BASED  
CIRRUS CLOUDS WILL THEN LINGER THROUGH THE AFTERNOON HOURS TOMORROW.  
 
DTW THRESHOLD PROBABILITIES...  
 
* LOW FOR CIGS AOB 5000 FEET TODAY, HIGH LATE TONIGHT AND  
OVERNIGHT.  
 
 
   
DTX WATCHES/WARNINGS/ADVISORIES  
 
MI...NONE.  
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LHZ442-443.  
 
GALE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING FOR  
LHZ362.  
 
GALE WARNING FROM 3 PM TUESDAY TO 6 AM EST WEDNESDAY FOR LHZ363-421-  
422-441-462.  
 
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LHZ421-441.  
 
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LCZ460.  
 
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ444.  
 
 
 
 
 
DISCUSSION...TF  
MARINE.......GM  
AVIATION.....AM  
 
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE  
AT WWW.WEATHER.GOV/DETROIT.  
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