616  
FXUS63 KGRR 310226  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
1026 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  
 

 
   
UPDATE
 
 
ISSUED AT 1026 PM EDT SUN MAR 30 2025  
 
THE MAIN UPDATE TO THE FORECAST THIS EVENING IS TO FRESHEN UP  
EVERYTHING BY GETTING RID OF ALL OF THE CONVECTION AND SEVERE  
WEATHER MENTION.  
 
EXCEPT FOR A NARROW BAND OF SHOWERS SE OF GRAND RAPIDS AT 1020 PM,  
THE REST OF THE AREA IS IN A RELATIVE LULL IN THE WAKE OF THE  
CONVECTION FROM EARLIER. WE ARE EXPECTING SOME RAIN SHOWERS TO  
MOVE BACK IN OVER THE NEXT FEW HOURS AS THE MAIN WAVE MOVES OVER  
THE AREA. THE FOCUS OF THESE SHOWERS WILL BE ACROSS THE WESTERN  
HALF OF THE FORECAST AREA WITH THE WAY THE WAVE IS SWINGING  
THROUGH.  
 
IT IS LIKELY THAT AS THE SHOWERS ARE ABOUT READY TO WIND DOWN  
TOWARD DAYBREAK, THAT THEY WILL CHANGE TO A LITTLE BIT OF SNOW  
BEFORE ENDING. THIS SHOULD NOT CAUSE ANY IMPACTS WITH THE GROUND  
WARM FROM THE PREVIOUS FEW DAYS.  
 

 
   
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 /00Z TAFS THROUGH 00Z TUESDAY/
 
 
ISSUED AT 752 PM EDT SUN MAR 30 2025  
 
SEVERE WEATHER THREAT, AND EVEN STORM THREAT IS OVER WITH FOR ALL  
OF THE TERMINALS FOR TONIGHT. WE ARE IN A RELATIVE LULL BETWEEN  
THE EXITING STORMS, AND ADDITIONAL SHOWERS THAT WILL DEVELOP  
TOWARD 02-04Z. THESE SHOWERS WILL BRING MVFR TO IFR CONDITIONS  
WITH IT IN THE FORM OF LOWER CEILINGS. KMKG HAS LIFR-VLIFR DUE TO  
STRATUS AND FOG OFF OF THE LAKE. THESE SHOWERS WILL CHANGE TO SOME  
SNOW SHOWERS TOWARD THE WEST, BEFORE SHOWERS END FOR INLAND AREAS  
TOWARD 10Z. THE SHOWERS WILL END LATER AT THE LAKESHORE.  
 
MOST OF THE DAY ON MONDAY WILL JUST HAVE LOWER CLOUDS IN THE MVFR  
CATEGORY LINGERING MOST OF THE DAY. WIND GUSTS FROM THE WEST, THEN  
NORTHWEST WILL GUST IN THE 20-28 KNOT RANGE THROUGH MOST OF THIS  
FORECAST PERIOD.  
 

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

 
 

 
 
UPDATE...NJJ  
DISCUSSION...DUKE  
AVIATION...NJJ  
 
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