543  
FXUS63 KGRR 300522  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
1222 AM EST THU JAN 30 2025  
   
KEY MESSAGES  
 
- MIXED PRECIPITATION EVENT THURSDAY NIGHT INTO FRIDAY  
 
- RAIN/SNOW CHANCES SUNDAY AND WARMER EARLY NEXT WEEK  
 
- QUIET AND COOLER MID-WEEK  
 
 
   
UPDATE  
 
ISSUED AT 912 PM EST WED JAN 29 2025  
 
NO APPRECIABLE CHANGES ARE NECESSARY TO THE FCST THIS EVENING.  
FAIR WX WILL CONTINUE TONIGHT WITH LOW TEMPS RANGING MAINLY FROM  
THE LOWER TEENS OVER OUR NE FCST AREA TO LOW TO MID 20S NEAR LAKE  
MI AND NEAR TO SOUTH OF I-96. RATHER EXTENSIVE CLEARING THIS  
EVENING WILL GIVE WAY TO SOME MID TO HIGH LEVEL CLOUD COVER THAT  
WILL STREAM IN FROM THE WNW OVERNIGHT.  
 
 
   
DISCUSSION  
 
ISSUED AT 245 PM EST WED JAN 29 2025  
 
- MIXED PRECIPITATION EVENT THURSDAY NIGHT INTO FRIDAY  
 
CLOUDS CONTINUE TO SLOWLY ERODE FROM SW TO NE THIS AFTERNOON AS THE  
UPPER JET LIFTS NE AWAY FROM THE AREA. THIS IS SETTING THE AREA UP  
FOR SOME SUNSHINE TO FINISH TODAY AND QUITE A BIT ALSO FOR THURSDAY.  
THE WINDS ARE ALSO DIMINISHING SOME THIS AFTERNOON, AND SHOULD NOT  
BE ANY STRONGER ON THURSDAY, COMPARED TO THIS AFTERNOON.  
 
THE NEXT LIMITED IMPACTFUL SYSTEM HAS ITS EYES SET ON THE AREA  
DURING THE THURSDAY NIGHT INTO FRIDAY TIME FRAME. THE UPPER LOW NEAR  
THE FOUR CORNERS REGION THIS AFTERNOON WILL BE RESPONSIBLE FOR THE  
THURSDAY NIGHT/FRIDAY PRECIPITATION CHANCES. THIS LOW WILL BE  
GETTING PUSHED OUT BY ENERGY OVER THE MIDDLE OF THE PACIFIC AND THE  
RIDGE MOVING ONSHORE OVER THE WEST U.S. COAST. THIS UPPER LOW WILL  
BE SLOWLY OPENING UP AND WEAKENING AS IT MOVES TOWARD THE REGION  
THURSDAY NIGHT AND FRIDAY.  
 
THE MAIN UNCERTAINTY WITH THIS SYSTEM FOR OUR AREA WILL BE HOW FAR  
NORTH DOES THE PRECIPITATION MAKE IT, AND HOW MUCH OF A WINTRY MIX  
COULD OCCUR WITH IT. THE NORTHWARD PROGRESS OF THE SYSTEM WILL BE  
LIMITED BY THE CLOSED MID LEVEL LOW OPENING UP, AND WITH A DRY FLOW  
FROM THE NE ON THE NORTHERN EDGE OF IT. FORTUNATELY THIS SYSTEM  
LOOKS LIKE IT WILL BE PRIMARILY RAIN THAT WILL KEEP THE IMPACTS  
LOWER. THIS IS THE RESULT OF IT BEING A SOUTHERN STREAM SYSTEM, WITH  
NO DEEP COLD AIR AVAILABLE TO IT. 850 MB TEMPS WILL BE MOSTLY ABOVE  
FREEZING UNTIL LATE FRIDAY.  
 
THERE MAY BE SOME VERY LIGHT FREEZING RAIN ACROSS CENTRAL LOWER  
WHERE SFC TEMPS WILL BE A TOUCH BELOW FREEZING AS THE RAIN BEGINS TO  
FALL THURSDAY NIGHT. THIS WILL BE SHORT LIVED HOWEVER AS THE RAIN  
WILL BRING THE WARMER AIR FROM ALOFT DOWN TO THE SFC. THERE MIGHT BE  
A BRIEF LIGHT GLAZE NORTH OF I-96 BEFORE TEMPS GO ABOVE FREEZING.  
THEN SNOW WILL TRY TO MIX IN WITH THE RAIN ON THE BACK END OF THE  
PRECIPITATION AS TEMPS ALOFT DROP BELOW FREEZING JUST BEFORE THE  
PRECIPITATION ENDS.  
 
- RAIN/SNOW CHANCES SUNDAY AND WARMER NEXT WEEK  
 
WE WILL SEE A BREAK IN THE PRECIPITATION CHANCES ON SATURDAY AS HIGH  
PRESSURE BUILDS IN OVER THE AREA. MUCH COOLER TEMPERATURES CAN BE  
EXPECTED WITH 850 MB TEMPS DROPPING TO AS LOW AS -3C TO -8C. THIS  
AIR IS NOT QUITE COLD ENOUGH TO FACILITATE LAKE EFFECT. PLUS, THE  
FLOW WILL BE COMING IN FROM THE NE.  
 
CLOUDS AND PRECIPITATION WILL MOVE BACK IN BY SUNDAY ACROSS THE  
AREA. WE WILL SEE A NORTHERN STREAM SHORT WAVE RIDE ALONG THE  
U.S./CANADIAN BORDER JUST NORTH OF OUR AREA. PRECIPITATION WILL  
BEGIN LATE SATURDAY NIGHT AND SUNDAY MORNING OUT AHEAD OF A  
STRENGTHENING WARM FRONT AHEAD OF THE SYSTEM. THIS LOOKS TO BE  
ANOTHER MIXED TYPE OF EVENT AT THE ONSET AS WARMER AIR WILL BE  
OVERRIDING THE RESIDUAL COLDER AIR FROM SATURDAY. THE CHANGEOVER  
WILL BE QUICK TO CHANGE TO RAIN AGAIN BEFORE ENDING SUNDAY  
MORNING WITH THE AREA GETTING INTO THE WARM SECTOR.  
 
850 MB TEMPS RISING INTO THE MID SINGLE DIGITS ABOVE 0C WILL SUPPORT  
HIGHS ON SUNDAY INTO THE 40S. MUCH OF THE DAY LOOKS DRY BEHIND THE  
WARM FRONT, AND AHEAD OF THE COLD FRONT THAT WILL COME THROUGH  
MONDAY MORNING. THE COLD FRONT WILL BRING A SMALL CHANCE OF RAIN  
SHOWERS, BUT THERE IS JUST NOT MUCH MOISTURE TO WORK WITH AT THAT  
TIME.  
 
- QUIET AND COOLER MID-WEEK  
 
THE AIR BEHIND THE FRONT THAT COMES THROUGH EARLY MONDAY WILL NOT BE  
SIGNIFICANTLY COLDER. THIS IS BECAUSE THE ORIGIN OF THE AIR MASS  
WILL BE FROM THE PACIFIC WITH A ZONAL FLOW TAKING SHAPE. WE WILL SEE  
ANOTHER SHOT OF COLDER AIR DROP DOWN BEGINNING ON TUESDAY AS A  
SHALLOW COLD AIR MASS DROPS DOWN INTO THE AREA ON A FAIRLY  
PERSISTENT FLOW FROM THE NNE. THIS FRONT WILL BRING A SMALL CHANCE  
OF A FEW RAIN AND/OR SNOW SHOWERS. ONCE THE FRONT MOVES THROUGH, WE  
STAY UNDER THE INFLUENCE OF COOL CANADIAN HIGH PRESSURE TO OUR WEST.  
THE FLOW WILL REMAIN FROM THE NE, SO LAKE EFFECT IS NOT EXPECTED TO  
BE A FACTOR.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/  
 
ISSUED AT 1221 AM EST THU JAN 30 2025  
 
VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE NEXT 24 HOURS.  
CURRENT BKN TO OVC CEILINGS AROUND 12,000 TO 15,000 FEET ARE  
EXPECTED TO GRADUALLY CLEAR THURSDAY MORNING. LOW LEVEL WINDS  
SHEAR WITH THE 850 MB JET IS EXPECTED TO DEVELOP THIS AFTERNOON  
AND THEN SHIFT EAST OF THE AREA THIS EVENING. MVFR TO LIFR  
CEILINGS MOVE IN SLOWLY FROM THE SOUTH THURSDAY NIGHT WITH MOST  
SITES DROPPING BELOW 1,000 FEET BY 6Z FRIDAY. ADDED PROB30S FOR  
RAIN/DRIZZLE AFTER 3Z TO AZO, BTL, AND JXN WITH THE APPROACHING  
SYSTEM.  
 
 
   
GRR WATCHES/WARNINGS/ADVISORIES  
 
MI...NONE.  
MARINE...NONE.  
 
 
 
 
 
UPDATE...LAURENS  
DISCUSSION...NJJ  
AVIATION...RAH  
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