178
FXUS63 KGRR 261136
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
736 AM EDT THU JUN 26 2025
KEY MESSAGES
- RAIN AND THUNDERSTORMS TODAY THROUGH FRIDAY
- HOT AND HUMID CONDITIONS CONTINUE
DISCUSSION
ISSUED AT 339 AM EDT THU JUN 26 2025
- RAIN AND THUNDERSTORMS TODAY THROUGH FRIDAY
WARM AIR ADVECTION, MUCAPE VALUES OF 500-1000J/KG, AND A POCKET OF
HIGHER 850MB MOISTURE IS SPARKING OFF SCATTERED SHOWERS AND
THUNDERSTORMS THIS MORNING ALONG WITH THE LOW LEVEL JET AND THE
REMNANT BOUNDARY FROM THE STORMS FROM WISCONSIN.
WITH THE MOISTURE AND INSTABILITY IN PLACE THROUGHOUT THE DAY AS
THE WARM FRONT SHIFTS NORTH SCATTERED SHOWERS AND THUNDERSTORMS
ARE EXPECTED. THIS AFTERNOON THE BETTER CHANCES WILL BE FOCUSED
EAST OF US-131 WITH THE POTENTIAL FOR SOME STRONG TO SEVERE
STORMS. WINDS WILL BE THE PRIMARY CONCERN BUT CAN'T RULE OUT THE
POTENTIAL FOR SOME SMALL HAIL.
A LULL IS POSSIBLE TONIGHT BUT WE'LL HAVE TO MONITOR THE
CONVECTION MOVING OUT OF WISCONSIN WITH THE SHORTWAVE TROUGH.
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT AS IT MOVES
THROUGH FRIDAY, AREAS SOUTH AND EAST OF GRAND RAPIDS HAVE THE BEST
CHANCE WITH INSTABILITY BUILDING THROUGHOUT THE DAY. HREF MEAN
SBCAPE VALUES ARE AROUND 2000 J/KG WITH AROUND 25 KNOTS OF SHEAR.
WHILE THE SHEAR ISN'T GREAT, THERE STILL IS THE POTENTIAL FOR
STRONGER STORMS, ESPECIALLY THE FARTHER EAST YOU GO. AGAIN WINDS
ARE THE PRIMARY CONCERN WITH ANY STRONGER STORM.
WITHIN THIS MOIST ENVIRONMENT, HEAVY RAINFALL IS LIKELY WITH ANY
SHOWER OR THUNDERSTORM (RATES AROUND 1 INCH PER HOUR).
THUNDERSTORMS THAT TRACK REPEATEDLY OVER THE SAME AREA COULD
CAUSE MINOR FLOODING ESPECIALLY IN URBAN AREAS AND KNOWN TROUBLE
SPOTS.
DRY CONDITIONS RETURN FRIDAY NIGHT AND CONTINUE THROUGH MOST OF
THE WEEKEND. THE ARRIVAL OF A LONGWAVE TROUGH AND A PARADE OF
EMBEDDED SHORTWAVES WILL BRING THE POTENTIAL FOR SHOWERS AND STORMS
BACK LATER SUNDAY INTO THE WORK WEEK NEXT WEEK.
- HOT AND HUMID CONDITIONS CONTINUE
DEW POINTS WILL CONTINUE TO BE IN THE 60S AND 70S THROUGH THE
WEEKEND AND EVEN INTO NEXT WEEK. WITH HIGHS MAINLY IN THE 80S,
HEAT INDICES WILL BE IN THE 90S MORE DAYS THAN NOT THROUGH THE
WEEKEND (SATURDAY LOOKS TO REMAIN IN THE 80S). AT THIS TIME NOT
EXPECTING VALUES TO REACH 100 OR MORE, BUT STILL TAKE CARE BY
STAYING HYDRATED AND LIMITING TIME OUTSIDE.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 736 AM EDT THU JUN 26 2025
POP UP SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS MORNING,
THEREFORE HAVE PROB30 GROUPS IN THE TAFS WITH BETTER CONFIDENCE
THIS AFTERNOON FOR AREAS ALONG AND SOUTH OF A AZO TO LAN LINE.
ANY THUNDERSTORM COULD PRODUCE GUSTY WINDS. HEAVY RAINFALL IS
LIKELY AND COULD REDUCE VISIBILITIES DOWN TO A MILE. RAINFALL
RATES AROUND AN INCH PER HOUR ARE POSSIBLE.
A LULL IN THUNDERSTORMS IS EXPECTED TONIGHT BEFORE ANOTHER ROUND
MOVES IN FRIDAY MORNING. THERE IS A CHANCE POP UP SHOWERS AND
STORMS COULD CONTINUE THROUGH THE OVERNIGHT HOURS BUT CHANCES ARE
NOT HIGH ENOUGH TO INCLUDE IN THE TAFS AT THIS TIME.
MARINE
ISSUED AT 339 AM EDT THU JUN 26 2025
PERIODS OF RAIN AND THUNDERSTORMS ARE EXPECTED THROUGH FRIDAY
BEFORE DRY CONDITIONS RETURN THIS WEEKEND. LIGHTNING WITH THE
POTENTIAL FOR HIGHER WINDS AND WAVES WILL CREATE HAZARDOUS
CONDITIONS FOR MARINERS AND BEACHGOERS.
OTHERWISE THE CURRENT WAVE AND WIND FORECAST REMAINS BELOW SMALL
CRAFT ADVISORY AND BEACH HAZARD STATEMENT CRITERIA THROUGH THE
WEEKEND.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...NONE.
DISCUSSION...RAH/THOMAS
AVIATION...RAH
MARINE...RAH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page