457  
FXUS63 KGRR 301937  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
337 PM EDT SUN MAR 30 2025  
   
KEY MESSAGES
 
 
- SEVERE WEATHER EXPECTED LATE THIS AFTERNOON AND EVENING  
 
- MID NEXT WEEK SYSTEM WITH POTENTIAL FOR BOTH WINTER AND SEVERE  
WEATHER  
 

 
   
DISCUSSION
 
 
ISSUED AT 337 PM EDT SUN MAR 30 2025  
 
- SEVERE WEATHER EXPECTED LATE THIS AFTERNOON AND EVENING  
 
THE WARM FRONT HAS SURGED NORTH OF I-96 THIS AFTERNOON AND NOW  
STRETCHES FROM JUST NORTH OF MUSKEGON ACROSS NORTHERN KENT COUNTY  
TO JUST NORTH OF ST. JOHNS. THE OPEN WARM SECTOR CONTINUES TO  
SURGE THROUGH THE CWA WITH CLEARING NOW MOVING UP INTO THE I-96  
CORRIDOR. MUCAPE VALUES HAVE SURGED TO 2,000 J/KG INTO THE I-94  
CORRIDOR NOW. SUFFICE IT TO SAY THE INSTABILITY HAS ARRIVED. THE  
MID LEVEL SHORTWAVE IS PLOWING NORTHEAST FROM MO/IL WHICH IS  
PROVIDING THE LIFT. A BROKEN LINE OF STORMS HAVE DEVELOPED ALONG  
AND AHEAD OF THE MID LEVEL WAVE OVER IL. THESE STORMS ARE RACING  
NORTHEAST TOWARDS OUR AREA AT THIS TIME AND ARE EXPECTED TO SWEEP  
FROM OUR SOUTHWEST LAKE MICHIGAN MARINE ZONES OVER MID LAKE TO  
EAST OF U.S. 127 BETWEEN 400PM AND 800PM.  
 
THE MAIN HAZARD CONTINUES TO LOOK LIKE STRONG DAMAGING WINDS GIVEN  
THE CONVECTION HAS ALREADY GONE LINEAR UPSTREAM. THE LINEAR MODE  
IS WHAT WAS EXPECTED. HAIL REMAINS A THREAT, BUT WE FEEL WIND  
CONTINUES TO BE THE HIGHEST THREAT. TORNADOES REMAIN A  
POSSIBILITY AS WELL, BUT LIKELY FROM TWO MODES. ONE BEING EMBEDDED  
QLCS TYPE TORNADOES AND THE OTHER BEING STORMS INTERACTING WITH  
THE WARM FRONT WHICH CURRENTLY IS JUST NORTH OF I-96. SUPERCELLS  
ARE NOT OUT OF THE QUESTION, BUT WITH A DOMINANT LINEAR MODE  
ALREADY OCCURRING THIS MODE IS LESS LIKELY. BOTTOM LINE, WE ARE  
EXPECTING A SEVERE WEATHER EPISODE TO SWEEP THROUGH THE AREA OVER  
THE COURSE OF THE NEXT 4-5 HOURS WITH DAMAGING WINDS LIKELY BEING  
THE MAIN THREAT.  
 
STORM MOVEMENT WILL BE TO THE NORTH AND NORTHEAST AT 50-60 MPH.  
LOCALLY HEAVY RAIN IS EXPECTED, BUT IT WILL NOT LAST LONG GIVEN  
THOSE SPEEDS.  
 
SOME WRAP AROUND MOISTURE WILL SWEEP THROUGH THE AREA OVERNIGHT  
AND IT WILL LIKELY CHANGE OVER TO SOME SNOW IN SPOTS BEFORE  
ENDING. TEMPERATURES PLUNGE INTO THE 30S OVER THE ENTIRE AT 12Z.  
 
- MID NEXT WEEK SYSTEM WITH POTENTIAL FOR BOTH WINTER AND SEVERE  
WEATHER  
 
OUR FORECAST FOCUS GOING FORWARD WILL BE ON THE MID NEXT WEEK  
SYSTEM. THE PRECIPITATION WILL COME IN AS A WINTRY MIX TUESDAY  
NIGHT INTO WEDNESDAY MORNING WITH BOTH SNOW AND FREEZING RAIN  
LOOKING LIKELY. THE DAY 4 SEVERE PROBABILITIES ARE HIGH IN THE SPC  
FORECAST FOR THAT RANGE IN TIME AND THAT IS APPROPRIATE GIVEN A  
STRONG SPRING TIME LOW MOVING THROUGH THE GREAT LAKES WHICH AGAIN  
PULLS 60F DEW POINTS NORTH INTO OUR AREA AT THE SURFACE. MORE ON  
THIS SYSTEM AS WE GO FORWARD.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
 
 
ISSUED AT 132 PM EDT SUN MAR 30 2025  
 
IFR/MVFR CONDITIONS COVER THE TERMINALS THIS AFTERNOON. A WARM  
FRONT IS CURRENTLY LIFTING NORTH ACROSS THE REGION WHICH WILL  
RESULT IN RISING CEILINGS.  
 
THUNDERSTORMS WILL IMPACT THE TERMINALS THIS AFTERNOON FROM  
21-24Z AS A COLD FRONT MOVES TOWARD THE STATE. WIND GUSTS IN  
EXCESS OF 50 KTS ARE POSSIBLE WITH THESE STORMS. ONCE THE STORMS  
MOVE EAST THIS EVENING, COLDER AIR WILL FLOW IN BEHIND THE FRONT  
AND SNOW SHOWERS ARE POSSIBLE OVERNIGHT AT MKG/GRR.  
 

 
   
GRR WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR LMZ844>849.  
 

 
 

 
 
DISCUSSION...DUKE  
AVIATION...04  
 
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