878
FXUS63 KGRR 052340
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
740 PM EDT TUE MAY 5 2026
KEY MESSAGES
- FROST AND FREEZE CONDITIONS EXPECTED NORTH OF I-96 TONIGHT
- ANOTHER CHANCE FOR WIDESPREAD FROST/FREEZE THURSDAY MORNING
- COOLER TEMPS WITH LIGHT RAIN TRENDING INTO THIS WEEKEND.
DISCUSSION
ISSUED AT 211 PM EDT TUE MAY 5 2026
- FROST AND FREEZE CONDITIONS EXPECTED NORTH OF I-96 TONIGHT
THE DRY GUSTY NORTHWESTERLY FLOW WILL CONTINUE THROUGH THE DAY.
THAT WILL DROP DEWPOINTS INTO THE 20S TO 30S THROUGH MUCH OF
NORTHERN LOWER MICHIGAN, INCLUDING OUR NORTHERN TWO TIER OF
COUNTIES, MAINLY REGIONS ALONG AND NORTH OF M 20. AS TEMPERATURES
DROP THIS EVENING THE WINDS WILL SLACKEN AND GIVEN THE DRY
DEWPOINTS AND CLEARING SKY, THE TEMPERATURES WILL DROP OVERNIGHT
INTO WEDNESDAY MORNING. GIVEN THOSE CONDITIONS WIDESPREAD FROST
IS LIKELY THROUGH NORTHERN MONTCALM COUNTY NORTHWARD. LAKE,
OSCEOLA AND CLARE WILL SEE THE STEEPEST DROP IN TEMPERATURES AND
THUS HAVE ISSUED A FREEZE WARNING FOR THOSE REGIONS. CONDITIONS
WILL IMPROVE FAIRLY QUICKLY AFTER SUNRISE WEDNESDAY MORNING.
- ANOTHER CHANCE FOR WIDESPREAD FROST/FREEZE THURSDAY MORNING
THE COLD NORTHWESTERLY FLOW WILL CONTINUE THROUGH TOMORROW. A
FAIRLY DRY UPPER LEVEL TROUGH WILL SLOWLY MOVE THROUGH THE UPPER
GREAT LAKES AS THE MOISTURE BOUNDARY REMAINS ENTRENCHED THROUGH
THE UPPER TENNESSEE RIVER VALLEY. THE BIG CONCERN WILL BE THE
FURTHER CONCERN FOR FROST AND FREEZE. 850MB LOWS TOMORROW EVENING
INTO THURSDAY WILL DROP TO -3C. THERE WILL BE SOME INCREASING MID
LEVEL MOISTURE WHICH COULD HINDER TEMPS FROM DROPPING. HOWEVER,
GIVEN THE DIURNAL SURFACE INVERSION, DRY AIR AT THE SURFACE AND
NEAR CALM WINDS, NEAR FREEZING TEMPERATURES COULD BE WIDESPREAD.
WILL SEE HOW THESE DEVELOP BUT MAY NEED HEADLINES TOMORROW NIGHT
AS WELL.
- COOLER TEMPS WITH RAIN TRENDING INTO THIS WEEKEND.
TEMPERATURES WILL CONTINUE TO TREND BELOW NORMAL THROUGH THE
REST OF THE WEEK, THOUGH THEY WILL MILDLY INCREASE THROUGH THE
LATTER HALF OF THE WEEK AND INTO THE WEEKEND. A LARGE UPPER LEVEL
TROUGH OVER CENTRAL CANADA WILL DOMINANT THE WEATHER PATTERN
THROUGH THE END OF THE WEEKEND INTO THE WEEKEND. THAT LOW WILL
CYCLE THROUGH UPPER AND MID LEVEL WAVES THROUGH THE REGION
BRINGING LATE DAY CHANCES FOR PRECIPITATION THROUGH SATURDAY. BEST
CHANCE FOR HEAVIER PRECIPITATION WILL BE SATURDAY EVENING
DEPENDING ON HOW THE BOUNDARY SITS. CURRENTLY IT COULD EXTEND
ACROSS SOUTHERN LOWER MICHIGAN WITH HEAVIEST PRECIP POSSIBLE AT
THIS TIME THROUGH SOUTHERN MICHIGAN.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 740 PM EDT TUE MAY 5 2026
VFR IS LIKELY THROUGH WEDNESDAY. CEILINGS TONIGHT WILL BE ABOVE
10,000 FEET WITH WINDS BECOMING LIGHT BETWEEN NW AND NE. WINDS
AROUND 10 KNOTS GUSTING 16 TO 20 KNOTS FROM THE W-NW IS EXPECTED
WITH LOWER ATMOSPHERIC MIXING DURING DAYTIME HEATING AFTER 15 Z.
DAYTIME CUMULUS BASES AROUND 6,000 FEET MAY DEVELOP UNDERNEATH
HIGHER ALTITUDE CLOUDS.
MARINE
ISSUED AT 216 PM EDT TUE MAY 5 2026
OVERALL TODAY INTO WEDNESDAY, WINDS 5 TO 15 KNOTS AND WAVES 1 TO
2 FEET. THERE WILL BE SOME WIND DIRECTION VARIABILITY, GENERALLY
WEST BECOMING SOUTH LATER THIS AFTERNOON, THEN VEERING NORTH OR
NORTHEAST LATE TONIGHT, THEN NORTHWEST WED LATE MORNING THROUGH
AFTERNOON. WAVES WILL BE A LITTLE HIGHER ON FRIDAY WITH 1 TO 3
FOOTERS, POSSIBLY 2 TO 4. SMALL CRAFT ADVISORY CONDITIONS APPEAR
UNLIKELY THROUGH THE COMING WEEKEND.
GRR WATCHES/WARNINGS/ADVISORIES
MI...FROST ADVISORY FROM 1 AM TO 8 AM EDT WEDNESDAY FOR MIZ037-
043>046-051.
FREEZE WARNING FROM 1 AM TO 8 AM EDT WEDNESDAY FOR MIZ038>040.
MARINE...NONE.
DISCUSSION...CERU
AVIATION...CAS
MARINE...CAS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page