161
FXUS63 KGRR 280642
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
242 AM EDT FRI AUG 28 2026
KEY MESSAGES
- WARMING UP INTO NEXT WEEK
- ON AND OFF CHANCES FOR SHOWERS AND THUNDERSTORMS SATURDAY INTO
NEXT WEEK
DISCUSSION
ISSUED AT 242 AM EDT FRI AUG 28 2026
- WARMING UP INTO NEXT WEEK
PRESSURE HEIGHTS WILL GRADUALLY RISE TODAY WITH SOUTHWEST FLOW
MOVING IN FOR SATURDAY AND CONTINUING INTO NEXT WEEK. WITHIN THE
SOUTHWEST FLOW WARMER TEMPERATURES AND HIGHER DEW POINTS WILL
ADVECT INTO THE REGION. HIGHS TODAY ARE EXPECTED TO BE AROUND 80,
BUT HIGH TEMPERATURES HAVE A 30 TO 60 PERCENT CHANCE TO HIT 90
MONDAY THROUGH THURSDAY WITH THE BEST CHANCES ON TUESDAY ACROSS
SOUTH CENTRAL MICHIGAN. DEW POINTS IN THE 60S TO NEAR 70 PAIRED
WITH THESE HOTTER TEMPERATURES WILL CAUSE HEAT INDEX VALUES TO BE
IN THE LOW TO MID 90S WITH UPPER 90S POSSIBLE TOWARD SOUTH CENTRAL
MICHIGAN ON TUESDAY.
- ON AND OFF CHANCES FOR SHOWERS AND THUNDERSTORMS SATURDAY INTO
NEXT WEEK
LOW CHANCE (10 PERCENT) FOR ANOTHER STRAY SHOWER THIS AFTERNOON,
OTHERWISE RAIN CHANCES HOLD OFF UNTIL SATURDAY NIGHT AND CONTINUE
OFF AN ON INTO NEXT WEEK. DEEP LIFT IS LACKING, BUT WITH
MOISTURE ADVECTION WITHIN THE SOUTHWEST FLOW NEAR THE SURFACE IT
WON'T TAKE MUCH TO SPARK OFF SHOWERS AND THUNDERSTORMS. THE MAIN
DRIVING FORCE FOR OUR CHANCES WILL BE THE LOW LEVEL JET AS IT
MOVES INTO THE AREA SUNDAY. THE CONVERGENCE FROM THE LOW LEVEL JET
WILL PROVIDE LIFT, BUT THERE IS THE POTENTIAL FOR STORMS TO TRAIN
OVER THE SAME AREA WHICH WOULD POSE A RISK FOR FLOODING.
CONFIDENCE FOR ANY ONE LOCATION IS NOT HIGH ENOUGH TO PINPOINT BUT
THE BEST CHANCES (40 TO 60 PERCENT) LOOK TO BE EACH NIGHT AS THE
LOW LEVEL JET RAMPS UP WITH LOWER CHANCES DURING THE DAY AS THE
LOW LEVEL JET WEAKENS.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 140 AM EDT FRI AUG 28 2026
VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS. A BRIEF PERIOD
OF MVFR VISIBILITIES IS POSSIBLE BETWEEN 10-12Z. ADDED A TEMPO
GROUP FOR GRR, BTL, LAN, AND JXN. OTHERWISE WINDS ARE EXPECTED TO
BECOME MORE WESTERLY WITH THE LAKE BREEZE THIS AFTERNOON WITH FEW
TO SCT CUMULUS AROUND 6000 FEET.
MARINE
ISSUED AT 242 AM EDT FRI AUG 28 2026
THE LAKE BREEZE WILL DEVELOP THIS AFTERNOON WITH WINDS BECOMING
MORE ONSHORE. SOUTHERLY WINDS THEN DEVELOP FOR SATURDAY AND
CONTINUE THROUGH MOST OF NEXT WEEK. WINDS WILL BE STRONGEST SUNDAY
INTO MONDAY WITH GUSTS AROUND 25 KNOTS POSSIBLE. WITH WARMER AIR
OVER THE OPEN WATERS IT MAY KEEP WINDS FROM HITTING SMALL CRAFT
ADVISORY CRITERIA UNTIL RIGHT ALONG THE LAKESHORE. WE'LL CONTINUE
TO MONITOR THESE TRENDS AS THIS COULD IMPACT WAVE HEIGHTS AND THE
NEED FOR HEADLINES SUNDAY NIGHT INTO MONDAY.
THUNDERSTORMS WILL BE POSSIBLE ON AND OFF SUNDAY INTO NEXT WEEK
WITH THE BEST CHANCES (40 TO 60 PERCENT) DURING THE OVERNIGHT
HOURS.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...NONE.
DISCUSSION...RAH
AVIATION...RAH
MARINE...RAH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page