861  
FXUS63 KGRR 171725  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
1225 PM EST WED DEC 17 2025  
   
KEY MESSAGES
 
 
- WARMER AIR HAS ARRIVED...RAIN EXPECTED THURSDAY  
 
- WINTER WEATHER EXPECTED THURSDAY NIGHT INTO FRIDAY MORNING  
 
- WINDY CONDITIONS LIKELY ON THURSDAY  
 

 
   
DISCUSSION
 
 
ISSUED AT 342 AM EST WED DEC 17 2025  
 
- WARMER AIR HAS ARRIVED...RAIN EXPECTED THURSDAY  
 
WARMER AIR HAS ALREADY ARRIVED IN SOUTHWEST MICHIGAN WITH  
TEMPERATURES HOLDING IN THE MIDDLE TO UPPER 30S AT 300AM. WE  
EXPECT HIGHS TODAY TO NOT BE MUCH HIGHER THAN CURRENT READINGS  
ACTUALLY AS COLD AIR ADVECTION OCCURS FOR A SHORT TIME BEHIND THE  
PASSAGE OF A COLD FRONT. HIGHS ON THURSDAY SHOULD RISE INTO THE  
40S IN THE STRONG SOUTHERLY FLOW OF AIR AHEAD OF A COLD FRONT. THE  
WARMEST AIR IS IN OUR AREA FOR ROUGHLY 8-12 HOURS BEFORE BEING  
SHUNTED TO THE EAST WITH THE NEXT COLD FRONT. WE LOST A SMALL  
AMOUNT OF SNOW YESTERDAY WITH THE SUNSHINE AND THAT SHOULD OCCUR  
AGAIN TODAY WITH HIGHS IN THE 30S. A MORE APPRECIABLE SNOW PACK  
LOSS SHOULD OCCUR ON THURSDAY WITH RAIN (0.25 TO 0.50) AND  
TEMPERATURES IN THE 40S. WE STILL HAVE 7 INCHES OF SNOW ON THE  
GROUND HERE AT THE OFFICE AS OF MIDNIGHT AND WE EXPECT TO SEE A  
NET LOSS AS WE WORK THROUGH TODAY AND TOMORROW. NEIGHBORHOOD  
ROADS AND SECONDARY ROADS THAT ARE SNOW COVERED NOW WILL CERTAINLY  
BECOME SLUSHY. AS FOR THE CHANCE OF FLOODING DUE TO RAIN AND  
SNOWMELT, WE ARE STILL NOT EXPECTING THAT DUE TO THE LACK OF  
HEAVY RAIN, TEMPERATURES NOT RISING ABOVE 50 AND THE SHORT  
DURATION OF THE WARM AIR. A FEW RIVER SITES WILL SEE SOLID WITHIN  
BANK RISES BUT NO FLOODING IS ANTICIPATED AT THIS TIME.  
 
- WINTER WEATHER EXPECTED THURSDAY NIGHT INTO FRIDAY MORNING  
 
A BRIEF PERIOD OF WINTRY WEATHER IS EXPECTED THURSDAY NIGHT INTO  
FRIDAY MORNING BEHIND A STRONG COLD FRONT. THERE WILL BE A DRY  
SLOT THAT MOVES THROUGH BEHIND THE STRONG COLD FRONT THURSDAY  
EVENING, BUT DEEPER WRAP AROUND MOISTURE WORKS BACK IN OVERNIGHT.  
THE 12 HOUR PERIOD FROM 100AM FRIDAY TO 100PM FRIDAY LOOKS TO BE  
THE BEST CHANCE AT SOME LAKE EFFECT SNOW AND LIGHT ACCUMULATIONS.  
MOISTURE IS A BIT SHALLOW, MORE CONFINED TO THE 1000-850MB  
LAYER, BUT THERE IS A PERIOD AROUND 700AM ON FRIDAY WHERE THE  
MOISTURE DEPTH INCREASES. WIND DRIVEN SNOW SHOWERS CAN BE EXPECTED  
LATE THURSDAY NIGHT AND FRIDAY MORNING. ACCUMULATIONS OF 1 TO 3  
INCHES OF NEW SNOW ARE POSSIBLE DURING THIS TIME NEAR AND WEST OF  
HIGHWAY 131. THE SNOW SHOULD RAPIDLY END IN THE MIDDAY HOURS ON  
FRIDAY AS MOISTURE IS SWEPT TO THE EAST AT THE SAME TIME THE UPPER  
CYCLONIC AXIS MOVES EAST AS WELL.  
 
- WINDY CONDITIONS LIKELY ON THURSDAY  
 
AT THIS POINT NOT THINKING STRONG WINDS ARE A SLAM DUNK ON  
THURSDAY. BUFKIT OVERVIEWS DO NOT SHOW US MIXING INTO ADVISORY  
LEVEL WINDS. IT LOOKS MORE LIKE 15-25 MPH WINDS OUT OF THE SOUTH  
WITH GUSTS TO 35-40 MPH. SO IT WILL CERTAINLY BE BRISK JUST NOT  
SURE WE WILL REACH 45 MPH GUSTS OVER ALL OF THE AREA. THE BETTER  
CHANCES FOR WIND GUSTS AT OR OVER 45 MPH WILL BE ALONG THE  
LAKESHORE AND THEN TOWARDS LAN/AZO/BTL AND JXN. NO WIND HEADLINE  
PLANS JUST YET.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
 
 
ISSUED AT 1224 PM EST WED DEC 17 2025  
 
MVFR CIGS ALONG I94 AND AT GRR SHOULD CLEAR BETWEEN NOW AND 19Z  
WITH VFR EXPECTED THE REST OF THE DAY. NOTABLE IMPACTS TO AVIATION  
IN THE FORMS OF WIND, CIGS, AND VISBYS ARE EXPECTED STARTING LATE  
TONIGHT/EARLY THURSDAY MORNING. INCREASING NON-CONVECTIVE LLWS IS  
EXPECTED AFTER 05Z AS A LOW- LEVEL JET STRENGTHENS WITH WINDS AT  
2KFT AS HIGH AS 60 KNOTS. GUSTS WILL INCREASE TO 25-30 KNOTS AS  
WELL, FIRST AT MKG AND AFTER 09Z AT INLAND TERMINALS. AFTER 09Z, A  
SURGE OF HIGHER DEWPOINTS ACROSS OUR MELTING SNOWPACK WILL BRING  
WIDESPREAD IFR AND LOWER CEILINGS ACROSS THE TERMINALS. JXN WILL  
BE THE LAST TO SEE IFR CONDITIONS NEAR 18Z. AFTER 12Z, RAIN  
SHOWERS WILL CAUSE VISBYS TO FALL TO MVFR/IFR GIVEN THE HIGH  
MOISTURE AVAILABILITY ALREADY IN PLACE.  
 

 
   
MARINE
 
 
ISSUED AT 446 AM EST WED DEC 17 2025  
 
WE HAVE GONE AHEAD AND ISSUED A GALE WARNING FROM TONIGHT THROUGH  
THURSDAY AND INTO FRIDAY MORNING. A PERIOD OF STRONG WINDS ARE  
EXPECTED ON LAKE MICHIGAN IN ASSOCIATION WITH DEEP LOW PRESSURE  
SYSTEM THAT WILL MOVE THROUGH THE GREAT LAKES OVER THE COURSE OF  
THE NEXT 48 HOURS.  
 
WE ARE IN THE FALLING STAGE OF THE MOST RECENT EVENT AND WAVES ARE  
EXPECTED TO FALL BELOW 4 FEET THIS AFTERNOON IN OUR NEARSHORE  
WATERS. WINDS INCREASE RAPIDLY THIS EVENING, LIKELY REACHING GALE  
FORCE OVERNIGHT OUT OF THE SOUTH. SOUTH GALES WILL PERSIST THROUGH  
THURSDAY BEFORE VEERING TO THE SOUTHWEST AND WEST INTO THURSDAY  
NIGHT. THE STRONGEST WINDS ARE POSSIBLE ON THURSDAY, 40 KNOTS,  
BEFORE BECOMING WEST GALES TO 35 KNOTS THURSDAY NIGHT. WAVES OVER  
10 FEET ARE EXPECTED A FAIR AMOUNT OF THE TIME FROM TONIGHT  
THROUGH THURSDAY NIGHT.  
 

 
   
GRR WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR  
LMZ844>849.  
GALE WARNING FROM 1 AM THURSDAY TO 7 AM EST FRIDAY FOR  
LMZ844>849.  
 

 
 

 
 
DISCUSSION...DUKE  
AVIATION...THOMAS  
MARINE...DUKE  
 
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