310  
FXUS63 KDTX 151730  
AFDDTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI  
1230 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. STRONG WINDS WILL ACCOMPANY THIS SYSTEM AS IT MOVES THROUGH  
THE REGION.  
 

 
   
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.  
 

 
   
PREV DISCUSSION
 
 
ISSUED AT 311 AM EST MON DEC 15 2025  
 
DISCUSSION...  
 
A PLUME OF SHALLOW, SUB 3.5 KFT AGL THETAE ADVECTED ACROSS PORTIONS  
OF SOUTHEAST MICHIGAN EARLIER THIS EVENING RESULTING IN LARGE FLAKE  
FLURRIES. THE MOISTURE, WHICH LIKELY HAD LAKE MICHIGAN ORIGINS WAS  
POOLED DIRECTLY BEHIND THE 850-700MB HIGH PRESSURE CENTER AND WAS  
THE INITIAL PHASE OF AIR MASS RECOVERY AND WARMING THAT WILL  
DOMINATE THE WEATHER THROUGH THE BEGINNING AND MIDDLE OF THE WEEK.  
EXIT REGION TO UPPER LEVEL SPEED MAX AND ATTENDANT WEAK PACIFIC  
SHORTWAVE WILL PUSH ACROSS THE NORTHERN GREAT LAKES LATER THIS  
MORNING AS BROAD RIDGING AND SUPERGEOSTROPHIC FLOW EXPANDS EASTWARD.  
CHANGING CURVATURE TO THE JET IMPULSE WILL PROVIDE FOR WEAK SYNOPTIC  
LIFT AND A WAVE OF WARM ADVECTION ALOFT. FORECAST SOUNDINGS AND THE  
FORECASTED VERTICAL PROFILE OF UVV CONTINUES TO SUGGEST SATURATION  
AND LIFT WILL BE VERY HIGH IN THE COLUMN, UPWARDS OF 8.0 KFT AGL.  
THE TENDENCY OF THE MODEL DATA FROM 24 HOURS AGO SUGGESTS THAT  
MIDLEVEL MOISTURE WILL BECOMING INCREASINGLY MORE SHALLOW TODAY AS  
DRYING WILL BE ACTIVELY OCCURING BETWEEN 12.0 AND 16.0 KFT AGL.  
MODELED QPF IS LESS IN THE 12-18Z TIME WINDOW AND SNOW ACCUMULATIONS  
WILL BE LIGHT AND INCONSEQUENTIAL FOR MOST AREAS. THE ONE EXCEPTION  
MAY BE THE THUMB WHERE LESS THAN ONE INCH IS POSSIBLE.  
INTERESTINGLY, LOCAL TIME-LAGGED ENSEMBLE OUTPUT FOR SITE PORT HOPE  
SUGGESTS A NEAR 90% PROBABILITY FOR 0.5 INCH OF SNOW AND APPROXIMATE  
40% CHANCE FOR AN INCH. NBM 5.0 OFFERS A 55% CHANCE TO MEASURE WITH  
AN APPROXIMATE 25% FOR 1 INCH IN THE NORTHERN THUMB. MUCH LESSER  
PROBABILITIES EXIST TO THE SOUTH INCLUDING IN VICINITY OF PORT  
HURON. NO SIGNIFICANT CHANGES WERE NEEDED TO THE GRIDDED POP  
FORECAST.  
 
RELATIVELY QUIET WEATHER IS EXPECTED TUESDAY AND INTO WEDNESDAY WITH  
FLOW EVOLVING MORE ZONAL AND THE HEIGHT PATTERN LESS AMPLIFIED THAT  
WHAT HAS RECENTLY BEEN OBSERVED. MODELS DO SHOW A BIG PUSH TO DEEPER  
WARM AIR ADVECTION ARRIVING TUESDAY. NOT EXPECTING MUCH IMPACT HERE  
ACROSS SOUTHEAST MICHIGAN AS DATA SUGGESTS ANY LIGHT PRECIPITATION  
POTENTIAL WILL REMAIN WELL NORTH OF THE CWA ACROSS NORTHEAST  
MICHIGAN LIKELY REQUIRING SOME ELEVATION. HIGHS TUESDAY ARE EXPECTED  
TO RISE TO THE FREEZING MARK. AN INFLECTION AND CORRESPONDING JET  
STREAK WILL SUPPORT A TROUGH STRUCTURE THROUGH MICHIGAN WEDNESDAY.  
DEEP MOISTURE IS SIGNIFICANTLY LACKING BUT PLAN VIEWS OF MOISTURE ON  
ISENTROPIC SURFACES SUGGESTS SOME LOW LEVEL MOISTURE ADVECTING OUT  
OF KY/TN NORTHEASTWARD, STREAMLINING AHEAD OF A WEAK COLD FRONT  
EARLY WEDNESDAY. FORECAST SOUNDINGS SHOWING AN EXTREMELY SHALLOW  
DEPTH TO THE MOISTURE WELL BELOW THE DGZ. COULD BE LOOKING AT SOME  
POCKETS OF DRIZZLE OR FREEZING DRIZZLE. THE CURRENT FORECAST HAS  
TEMPERATURES AT 32/33F IN THE 10-13Z WEDNESDAY TIMEFRAME.  
 
MODELS CONTINUE TO SUPPORT A DEEP MIDLEVEL TROUGH AND DYNAMIC  
SHORTWAVE TROUGH PUSHING ACROSS CENTRAL/NORTHERN GREAT PLAINS  
THURSDAY. HIGH CONFIDENCE EXISTS AT THIS VANTAGE POINT THAT GREATEST  
DEFORMATION FORCING AND COLD CONVEYOR PROCESSES WITH MID LATITUDE  
CYCLONE WILL IMPACT PORTIONS OF CANADA, WELL NORTH OF SOUTHEAST  
MICHIGAN. VERY HIGH CONFIDENCE IN WARM RAIN PRECIPITATION TYPE AS  
MODEL SOUNDINGS SUPPORT VERY WARM THERMAL PROFILE IN THE LOWEST 6.0  
KFT AGL WITH MAXIMUM TEMPERATURE AT 850MB OF A POSITIVE 5-6C. THE  
MODEL TREND NOW SUGGESTS THAT STRONG WIND POTENTIAL WITH THE SYSTEM  
MAY BE A LITTLE LESS THAN PREVIOUSLY THOUGHT PARTICULARLY OVER  
SOUTHEAST MICHIGAN (STILL BREEZY HOWEVER). THE MAIN REASON IS THAT  
THE TRACK OF THE CYCLONE COULD VERIFY NORTH OF LAKE SUPERIOR WITH A  
MUCH MORE DIFFUSE SURFACE TROUGH STRUCTURE EXTENDING SOUTHWARD  
THROUGH THE CWA. THERE HAVE BEEN SUGGESTIONS THE COLD ADVECTION WITH  
THE FRONT MAY COME IN TWO PIECES WITH THE TRUE COLD AIR AND BEST  
NEAR SURFACE LAPSE RATES WELL REMOVED TO THE WEST OF THE WIND SHIFT.  
ADDITIONALLY, NOCTURNAL TIMING OF THE COLD FRONT WOULD HAVE AN  
IMPACT ON DOWNWARD MOMENTUM TRANSFER. HIGHS THURSDAY ARE EXPECTED TO  
BE IN THE MIDDLE 40S. WITH HIGHS FRIDAY BEHIND THE COLD FRONT BACK  
INTO THE MIDDLE 20S.  
 
MARINE...  
 
WE WILL RESIDE ON THE NORTHERN FRINGE OF AN AREA OF HIGH PRESSURE  
CENTERED OVER THE OHIO VALLEY TODAY. WINDS HAVE TURNED TO THE  
SOUTHWEST OVERNIGHT AHEAD OF AN APPROACHING TROUGH DROPPING INTO THE  
NORTHERN GREAT LAKES. THE TIGHTENING OF THE GRADIENT ALONG WIT H A  
STRONG LOW LEVEL JET PASSING OVER THE REGION WILL LEAD TO WINDS  
GUSTING TO AROUND 30 KNOTS THOUGH THE EARLY PART OF THE DAY. LOW  
CONFIDENCE SCENERIO REGARDING GALE POTENTIAL TODAY BUT COULD SEE AN  
ISOLATED GUST TO GALE FORCE OR TWO BUT THE WINDOW LOOKS FAIRLY  
NARROW LATE MORNING INTO THE EARLY AFTERNOON FOR THESE HIGHER GUSTS.  
WINDS WILL REMAIN ELEVATED THROUGH THE FIRST HALF OF THE WEEK AS A  
SERIES OF LOWS PASS NEAR THE GREAT LAKES. SMALL CRAFT ADVISORIES ARE  
IN EFFECT THROUGH THE DAY TO COVER THESE HIGHER WINDS AND WAVES. THE  
NEXT SYSTEM WILL MOVE IN ON TUESDAY WHICH AGAIN IS ALREADY  
ADVERTISING SOUTHWESTERLY GUSTS TO GALES TUESDAY NIGHT. WILL HOLD  
OFF ON ANOTHER GALE WATCH AT THIS TIME BUT ONE MAY BE NEEDED IN THE  
NEXT 24 HOURS IF WIND GUSTS REMAIN UNCHANGED.  
 

 
   
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 WATCH FROM TUESDAY AFTERNOON THROUGH LATE TUESDAY NIGHT 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.  
 

 
 

 
 
AVIATION.....AM  
DISCUSSION...CB  
MARINE.......DRK  
 
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE  
AT WWW.WEATHER.GOV/DETROIT.  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab MI Page Main Text Page