403  
FXUS63 KDTX 070132  
AFDDTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI  
932 PM EDT MON OCT 6 2025  
   
KEY MESSAGES
 
 
- SHOWERS AND SCATTERED THUNDERSTORMS TONIGHT AND MONDAY MORNING,  
LINGERING INTO THE AFTERNOON TOWARD METRO DETROIT.  
 
- MUCH COOLER CONDITIONS TUESDAY THROUGH THE END OF THE WEEK.  
 

 
   
UPDATE
 
 
CLUSTERS OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO ADVANCE  
INTO SE MI THIS EVENING, SLIGHTLY BEHIND SCHEDULE BUT STILL SET TO  
EXPAND IN COVERAGE AND INTENSITY DURING THE NIGHT. ONGOING ACTIVITY  
ALONG AND AHEAD OF THE FRONT IS WEAKLY SURFACE BASED IN MLCAPE  
AROUND 500 J/KG ACCORDING TO HOURLY MESOANALYSIS. THESE WILL BE  
MONITORED FOR WIND GUST POTENTIAL WHILE MOVING ALONG AND NEAR THE I-  
69 CORRIDOR THIS EVENING GIVEN SOME NEGATIVE BUOYANCY SHOWN IN THE  
00Z DTX SOUNDING. THE SETUP GRADUALLY TRANSITIONS TO MORE OF AN  
ELEVATED CHARACTER ALONG AND POST FRONT IN A SIMILAR MUCAPE  
ENVIRONMENT. THE BOOST IN COVERAGE AND INTENSITY COMES AS THE  
ENTRANCE REGION OF THE UPPER JET AND 500 MB TROUGH MOVE CLOSER FROM  
THE UPPER MIDWEST WHILE ENERGIZING A LOW LEVEL JET RESPONSE WITHIN  
FRONTAL ZONE/LOW LEVEL MOISTURE AXIS. A BAND OF SHOWERS SOLIDIFIES  
IN THIS FORCING WITH POCKETS OF THUNDERSTORMS CAPABLE OF LOCALIZED  
HEAVIER RAINFALL RATES ACROSS SE MI, MAINLY TOWARD THE TRI CITIES  
AND NORTHERN THUMB IN MOST RECENT HI-RES MODEL PROJECTIONS. THE  
GOING FORECAST IS THEN ON TRACK WITH A FEW TWEAKS TO TIMING ON THE  
FRONT END THIS EVENING. WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS  
CONTINUE THROUGH THE MORNING UNTIL ENDING NW TO SE AND FINALLY  
EXITING THE DETROIT METRO AREA TOWARD MID AFTERNOON.  
 

 
   
PREV DISCUSSION
 
 
ISSUED AT 708 PM EDT MON OCT 6 2025  
 
AVIATION...  
 
A COLD FRONT MOVING NW TO SE ACROSS LOWER MI IS THE PRIMARY FORECAST  
FOCUS FOR TONIGHT AND TUESDAY. IT BRINGS INCREASING COVERAGE OF  
SHOWERS AND SCATTERED THUNDERSTORMS TO THE SE MI TERMINAL CORRIDOR  
THIS EVENING, WHILE A FEW ADDITIONAL SHOWERS GRAZE THE DTW AREA,  
PEAKING IN COVERAGE/INTENSITY ALL AREAS AFTER MIDNIGHT INTO TUESDAY  
MORNING AS THE FRONT MOVES OVERHEAD. THE FRONT ALSO BRINGS SOLID  
COVERAGE OF MVFR CEILING WITH A GREATER IFR COMPONENT ALSO TOWARD  
SUNRISE WHILE AT THE SAME TIME IMPROVING QUICKLY FROM MBS SOUTHWARD  
AFTER SUNRISE. MVFR CEILING AND POST FRONTAL SHOWERS LINGER LONGER  
TOWARD DTW, HOWEVER A RETURN TO VFR IS PROJECTED AT ALL LOCATIONS BY  
21Z TUESDAY AFTERNOON.  
 
FOR DTW/D21 CONVECTION... THERE IS A LOW CHANCE (30%) FOR  
THUNDERSTORMS TO IMPACT THE DTW AIRSPACE LATE TONIGHT AND TUESDAY  
MORNING.  
 
DTW THRESHOLD PROBABILITIES...  
 
* HIGH FOR CEILING 5000 FT OR LESS LATE TONIGHT AND TUESDAY  
MORNING.  
 
* LOW FOR THUNDERSTORMS LATE TONIGHT AND TUESDAY MORNING BETWEEN 10Z  
AND 14Z.  
 
PREV DISCUSSION...  
ISSUED AT 301 PM EDT MON OCT 6 2025  
 
DISCUSSION...  
 
LAST DAY OF THE ANOMALOUSLY WARMER TEMPERATURES IS UNDERWAY UNDER  
BRISK SOUTHWEST FLOW WHICH HAVE PROPELLED TEMPERATURES BACK INTO THE  
80S THIS AFTERNOON. A STARK CHANGE IN TEMPERATURES WILL ARRIVE BY  
TOMORROW AFTER THE PASSAGE OF A COLD FRONT, WHICH ALSO BRINGS SHOWER  
AND THUNDERSTORM CHANCES.  
 
A STRONG SHORTWAVE IMPULSE WILL ROUND INTO WESTERN ONTARIO THROUGH  
THE DAY TODAY AND WILL AMPLIFY THE GREATER TROUGH FEATURE THROUGH  
THE NORTHERN PLAINS, AIDING IN THE CONTINUED PROGRESSION OF A STRONG  
COLD FRONT THAT NOW EXTENDS THROUGH NORTHERN LOWER MICHIGAN. SLOW  
PROGRESSION OF THE FRONT WILL CONTINUE THROUGH THE MORNING HOURS  
TOMORROW AS DEEP-LAYER STEERING FLOW REMAINS LARGELY PARALLEL TO THE  
BOUNDARY. AS THE FRONT ARRIVES WITHIN THE VICINITY OF AND OVER SE  
MI, NUMEROUS SHOWERS WITH EMBEDDED THUNDERSTORMS WILL MOVE IN, AIDED  
FROM THE EFFICIENT DEEP TRANSPORT OF HIGH THETA-E MOISTURE COUPLED  
WITH ELEVATED INSTABILITY.  
 
HI-RES MODELS CONTINUE TO PICK UP ON THE POTENTIAL FOR PREFRONTAL  
DEVELOPMENT LATE TONIGHT THROUGH MIDNIGHT FAVORED ACROSS THE TRI-  
CITIES AND THUMB. UNIDIRECTIONAL WIND DIRECTION COULD PROMOTE SOME  
ISL TO SCT PULSE OR LINEAR SEGMENTED CONVECTION. SOME POCKETS OF  
LOCALIZED GUSTY WINDS WILL BE POSSIBLE WITH THIS ACTIVITY, BUT THE  
OVERALL ELEVATED NATURE PRECLUDES ANY STRONGER WORDING OF DAMAGING  
GUST POTENTIAL. FRONTAL PROGRESSION WILL THEN PICK UP THROUGH THE MID  
TO LATE MORNING HOURS AS FLOW ALOFT VEERS, ENHANCING THE  
FRONTOGENETIC RESPONSE, ESPECIALLY ACROSS THE TRI-CITIES AND THUMB.  
THE COLD FRONT AND SUBSEQUENT RAIN CHANCES CLEAR THE CWA ENTIRELY IN  
THE AFTERNOON HOURS.  
 
AN ANOMALOUSLY STRONG SURFACE HIGH PRESSURE SYSTEM IS THEN SET TO  
BUILD INTO THE AREA THROUGH THE MIDWEEK PERIOD, WITH CENTRAL SLP  
VALUES EXPECTED TO REACH OF EXCEED THE 99.5TH PERCENTILE OF THE  
CLIMATOLOGICAL DISTRIBUTION FOR THIS TIME OF YEAR. THE EXTREME  
STRENGTH IS AMPLIFIED BY A SYNERGISTIC DYNAMIC SETUP. SPECIFICALLY,  
THE GREAT LAKES WILL BE SITUATED BENEATH THE RIGHT EXIT REGION OF THE  
NNW-SSE JET OVER ONTARIO WHICH WILL MAXIMIZE UPPER-LEVEL CONFLUENT  
FLOW. COUPLED WITH COLD AIR ADVECTION IN THE LOW LEVELS THROUGH 850MB  
WHICH INCREASES DENSITY OF THE COLUMN, SLP INCREASES AND PEAKS BY  
THURSDAY MORNING. THE PASSAGE OF THE COLD FRONT AND THERMAL TROUGH  
BRINGS STARK TEMPERATURE CHANGES TUES-THURS AFTERNOON WITH HIGHS IN  
THE LOW TO MID 60S AND LOWS 30S (WED-FRI MORNING). THE COOLEST NIGHT  
WILL LIKELY BE THURSDAY MORNING AS LOWS DROP INTO THE LOW TO MID 30S,  
WHICH WILL BRING FROST AND FREEZE CONCERNS. OTHERWISE, THIS  
AFOREMENTIONED SETUP BRINGS DRY WEATHER AND CLEAR SKIES THROUGH THE  
MIDWEEK PERIOD.  
 
MARINE...  
 
A COLD FRONT WILL CONTINUE TO SLOWLY TRACK SOUTH THROUGH THE CENTRAL  
GREAT LAKES THIS EVENING AND TONIGHT, WITH BLOSSOMING SHOWERS AND  
EMBEDDED THUNDERSTORMS EXPECTED. STRONGER THUNDERSTORMS WILL BE  
CAPABLE OF PRODUCING WIND GUSTS OF 35+ KNOTS.  
 
POST FRONTAL COLD AIR ADVECTION THROUGH TOMORROW AS 850 MB TEMPS  
FALL INTO THE LOW SINGLE NUMBERS TO NEAR ZERO. A PERIOD OF WIND  
GUSTS UP TO 30 KNOTS IS EXPECTED ACROSS NORTHERN LAKE HURON TUESDAY  
EVENING WITH THE INCREASED BOUNDARY LAYER BEFORE WINDS SLOWLY  
DIMINISH AND VEER NORTH-NORTHEAST ON WEDNESDAY AS EXPANSIVE HIGH  
PRESSURE ARRIVES. DESPITE WINDS DIMINISHING, THE NORTHERLY FLOW WILL  
LEAD TO LARGER WAVES OVER THE SOUTHERN LAKE HURON BASIN TUESDAY  
EVENING INTO WEDNESDAY, WITH SMALL CRAFT ADVISORIES NEEDED DURING  
THIS TIME FOR THE NEARSHORE WATERS AS THE COLD AIRMASS LEADS TO  
UNSTABLE LOW LEVEL PROFILES CONDUCIVE TO GOOD WAVE GROWTH WITH THE  
LONG NORTH-NORTHEAST FETCH.  
 
HYDROLOGY...  
 
A COLD FRONT WILL BRING NUMEROUS SHOWERS WITH EMBEDDED THUNDERSTORMS  
TO SE MI LATE TONIGHT THROUGH TOMORROW MORNING. BASIN AVERAGED  
RAINFALL TOTALS ARE EXPECTED TO RANGE BETWEEN A QUARTER-INCH TO A  
HALF-INCH OF RAINFALL, WITH SOME LOCALIZED HIGHER AMOUNTS LIKELY  
WITH ANY REPEATED SHOWER OR THUNDERSTORM ACTIVITY. THE MOST LIKELY  
LOCATION FOR REPEATED ACTIVITY WILL RESIDE ALONG OR NORTH OF I-69,  
THROUGH THE TRI-CITIES AND THUMB, WHERE TOTALS CLOSER TO AN INCH OR  
MORE WILL BE POSSIBLE. GIVEN THE ANTECEDENT DRY CONDITIONS,  
LOCALIZED FLOODING IS NOT EXPECTED.  
 

 
   
DTX WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
 
LAKE HURON...SMALL CRAFT ADVISORY FROM 10 PM TUESDAY TO 10 PM EDT WEDNESDAY FOR  
LHZ421-441>443.  
 
SMALL CRAFT ADVISORY FROM 10 PM TUESDAY TO 4 PM EDT WEDNESDAY FOR  
LHZ422.  
 
LAKE ST CLAIR...NONE.  
 
MICHIGAN WATERS OF LAKE ERIE...NONE.  
 

 
 

 
 
UPDATE.......BT  
AVIATION.....BT  
DISCUSSION...AM  
MARINE.......SF  
HYDROLOGY....AM  
 
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