562
FXUS63 KGRR 010800
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
400 AM EDT WED APR 1 2026
KEY MESSAGES
- THREAT FOR FREEZING RAIN TONIGHT INTO THURSDAY MORNING
- CHANCE FOR SEVERE WEATHER THURSDAY AFTERNOON/NIGHT
- ANOTHER ROUND OF STRONG STORMS POSSIBLE ON SATURDAY
- RAIN TOTALS ADD UP AS WE MOVE INTO THE WEEKEND
DISCUSSION
ISSUED AT 400 AM EDT WED APR 1 2026
- THREAT FOR FREEZING RAIN TONIGHT INTO THURSDAY MORNING
AN UPPER TROUGH SWINGING THROUGH CALIFORNIA THIS MORNING WILL ZIP
THROUGH THE ROCKIES TODAY, THE PLAINS TONIGHT AND INTO THE UPPER
MIDWEST ON THURSDAY. THIS UPPER TROUGH WILL AID IN BRINGING THE
FRONT THAT MOVED THROUGH YESTERDAY BACK AS A WARM FRONT ON
THURSDAY. SOME RESIDUAL COLD AIR WILL LINGER ACROSS INTERIOR
CENTRAL MICHIGAN LATE TONIGHT AND INTO THURSDAY MORNING AS THE
WARMER AIR SURGES IN ALOFT. THIS WILL SET THE STAGE FOR A PERIOD
OF FREEZING RAIN LATE TONIGHT AND THURSDAY MORNING. FEEL THE
FREEZING RAIN WILL MAINLY BE CONFINED TO OSCEOLA AND CLARE
COUNTIES WHERE SOME OF OUR HIGHEST GROUND IS FOUND IN THE GRR
FORECAST AREA. FROM ROUGHLY 200AM THROUGH 1000AM OR SO THERE IS A
THREAT FOR SOME ICING. WE ARE NOT THINKING THIS WILL BE HEAVY, UP
TO A TENTH OF AN INCH AT MOST. WARM AIR WILL BE SURGING IN SO WHAT
DOES ACCUMULATE WILL BEGIN TO MELT. THAT SAID, IT DOES NOT TAKE
MUCH ICE ACCUMULATION TO CAUSE ISSUES WITH TRAVEL AND IT WILL
LIKELY BE ONGOING FOR THE MORNING COMMUTE UP THERE. BOTTOM LINE, A
WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR OSCEOLA AND CLARE
COUNTIES FROM 200AM THURSDAY TO NOON ON THURSDAY.
- CHANCE FOR SEVERE WEATHER THURSDAY AFTERNOON/NIGHT
THE SPC HAS PLACED THE ENTIRE FORECAST AREA IN A SLIGHT RISK FOR
SEVERE WEATHER ON THURSDAY. THREATS WILL EXIST WITH BOTH THE WARM
FRONT MOVING IN DURING THE AFTERNOON AND THE COLD FRONT SWEEPING
THROUGH THURSDAY NIGHT. INSTABILITY IN THE MODELS IS MODEST ON THE
ORDER OF 500 TO 1,000 J/KG, BUT THAT COULD BE A LITTLE UNDERDONE
AS SURFACE DEW POINTS ARE FORECAST TO HIT 60F, WHILE 850MB DEW
POINTS REACH 50F/10C. THAT IS MORE THAN ENOUGH MOISTURE TO WORK
WITH IN COMBINATION WITH A SHORTWAVE UPPER TROUGH SWINGING THROUGH
AND BOTH A WARM FRONTAL AND COLD FRONTAL PASSAGE. WINDS ARE
FAIRLY UNIDIRECTIONAL AND STRONG (850MB LLJ ON THE ORDER OF 50 KTS
AND THE 500MB MID LEVEL JET AROUND 60 KTS) SO DAMAGING WINDS ARE
CERTAINLY A THREAT. ALL THREATS ARE IN PLAY GIVEN THE STRENGTH OF
THE WIND FIELDS. ROUNDS OF CONVECTION ARE EXPECTED DURING THIS
TIME FRAME WITH PLENTY OF CLOUDS AND SHOWERS AROUND, SO THE
DETAILS MAY NOT BECOME CLEAR UNTIL TOMORROW.
- ANOTHER ROUND OF STRONG STORMS POSSIBLE ON SATURDAY
ANOTHER LOW WILL MOVE THROUGH THE AREA ON SATURDAY ASSOCIATED WITH
A STRONGER UPPER TROUGH. WIND FIELDS WITH THIS SYSTEM ARE EVEN
STRONGER ALOFT WITH A 60KT LOW LEVEL JET AND A 70KT MID LEVEL JET.
THE QUESTION IS HOW MUCH INSTABILITY WE WILL HAVE BEFORE THE COLD
FRONT SWEEP EAST DURING THE DAY. IF THE TIMING OF THE FRONT SLOWS
UP JUST A BIT IT WILL PLACE A PORTION OF OUR AREA IN THE WARM
SECTOR AT MAX HEATING. WE WILL BE WATCHING THIS TIME FRAME CLOSELY
FOR ANOTHER ROUND OF POTENTIAL SEVERE WEATHER.
- RAIN TOTALS ADD UP AS WE MOVE INTO THE WEEKEND
WE ARE LIKELY LOOKING AT A FAIRLY WIDESPREAD 1 TO 2 INCHES OF RAIN
BETWEEN TODAY AND SUNDAY. THE RAIN WILL COME IN A COUPLE MAIN
ROUNDS... THURSDAY/THURSDAY NIGHT AND FRIDAY NIGHT INTO SATURDAY.
BOTH ROUNDS OF RAIN WILL BE DRIVEN BY A WARM FRONTAL AND COLD
FRONTAL PASSAGE SO GOOD FORCING WILL BE DRIVING THE RAIN.
PRECIPITABLE WATER VALUES WITH BOTH SYSTEMS WILL BE NEAR 1.5
INCHES WHICH WILL CERTAINLY RESULT IN PERIODS OF HEAVY RAIN. WE
WILL BE MONITORING RIVER FORECASTS AS WE HEAD THROUGH THE NEXT FEW
DAYS. SOME SHORT TERM AERIAL FLOODING IS POSSIBLE GIVEN THE
CONVECTIVE RAINS DRIVEN BY MULTIPLE FRONTS. WE MAY ALSO SEE SOME
LOCALIZED RIVER FLOODING AS WELL, BUT THAT WILL COME INTO BETTER
FOCUS AS THE QPF MAKES IT INTO THE RIVER MODELS. WE WILL KNOW MORE
TODAY AND THURSDAY.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 149 AM EDT WED APR 1 2026
AT 06Z SURFACE LOW PRESSURE IS CENTERED OVER LAKE ERIE WITH A COLD
FRONT STRETCHING TO THE SOUTHWEST OVER CENTRAL INDIANA. LOWER
MICHIGAN IS SITUATED IN THE NORTH FLOW BEHIND THE FRONT WITH
WIDESPREAD LOW CEILINGS IN PLACE. IFR CONDITIONS ARE LOCATED
ALONG THE I-94 TAF SITES WITH MVFR CONDITIONS OCCURRING AT THE
I-96 TAF SITES. NOT MUCH IMPROVEMENT IS EXPECTED THE REMAINDER OF
THE NIGHT WITH IFR AND MVFR CEILINGS CONTINUING. THE NORTHERLY
DRYING FLOW MAY LIFT THE I-94 CEILINGS TO MVFR BY 12Z. MVFR
CEILINGS WILL PERSIST AT ALL TAF SITES DURING THE DAYLIGHT HOURS
OF WEDNESDAY MORNING. AN IMPROVEMENT TO VFR IS LIKELY IN THE
AFTERNOON AT THE I-96 TAF SITES WITH THE LOWER CLOUDS LIKELY
HANGING ON ALONG I-94. CONDITIONS WILL BEGIN TO DETERIORATE AGAIN
AFTER DARK WEDNESDAY EVENING AS THE FRONT WORKS BACK IN OUR
DIRECTION AS A WARM FRONT. WINDS THROUGH THE TAF PERIOD WILL
GRADUALLY VEER FROM NORTH TO NORTHEAST AND EAST. WIND SPEEDS MUCH
OF THE TIME WILL BE IN THE 8-15 KNOT RANGE.
MARINE
ISSUED AT 400 AM EDT TUE MAR 31 2026
WE WILL MAINTAIN THE SMALL CRAFT ADVISORY (SCA) FOR THE REMAINDER
OF THE NIGHT AS SOME RESIDUAL WAVE ACTION CONTINUES FROM THE
NORTH FLOW THAT RAMPED UP BEHIND THE COLD FRONTAL PASSAGE
YESTERDAY. THE WAVEWATCH3 SHOWS SOME 3-5 FOOT WAVES LIKELY
OCCURRING UP NEAR THE POINTS AND DOWN TOWARDS SOUTH HAVEN.
TODAY AND INTO TONIGHT THE FLOW GOES MORE OFF SHORE, FIRST
NORTHEAST TODAY AND EAST TONIGHT. WE WILL DECIDE TODAY WHETHER THE
OFFSHORE FLOW IS WORTHY OF A SMALL CRAFT HEADLINE MAINLY FOR
WINDS. THURSDAY AND INTO THURSDAY NIGHT THE WINDS VEER TO THE
SOUTH AND INCREASE MAKING SCA CONDITIONS LIKELY. THE TYPICAL
CAVEATS APPLY THOUGH WITH A SPRING TIME WARM AIR ADVECTION WIND.
THE MODELS MAY BE MIXING DOWN TOO MUCH WIND DURING THIS TIME FRAME
AND THE WINDS AND WAVES MAY NOT BE QUITE AS HIGH AS ADVERTISED.
GRR WATCHES/WARNINGS/ADVISORIES
MI...WINTER WEATHER ADVISORY FROM 2 AM TO NOON EDT THURSDAY FOR
MIZ039-040.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR LMZ844>849.
DISCUSSION...DUKE
AVIATION...DUKE
MARINE...DUKE
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