167
FXUS63 KGRR 091853
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
253 PM EDT MON JUN 9 2025
KEY MESSAGES
- ROUND OF THUNDERSTORMS THIS AFTERNOON AND EVENING
- ADDITIONAL THUNDERSTORM CHANCES LATE WEEK
DISCUSSION
ISSUED AT 253 PM EDT MON JUN 9 2025
- ROUND OF THUNDERSTORMS THIS AFTERNOON AND EVENING
AS DAYTIME INSTABILITY HAS INCREASE TO AROUND 500-1000 J/KG THIS
AFTERNOON WE ARE ALREADY SEEING SHOWERS AND STORMS DEVELOP AHEAD
OF THE MAIN LINE CURRENTLY MOVING ACROSS LAKE MICHIGAN. WE WILL
ALSO SEE A CORE OF SLIGHTLY STRONGER 850MB WINDS 30-35 KNOTS MOVE
IN WITH THE LINE. SOUNDING PROFILES HAVE AN INVERTED V LOOK TO
THEM SIGNIFYING HIGHER CLOUD BASES AND DRIER AIR AT THE SURFACE.
WITH THE SYNOPTIC LIFT MOVING IN WITH THE UPPER LEVEL LOW, MODEST
SHEAR, INSTABILITY, AND DRY AIR AT THE SURFACE SOME STRONG TO
SEVERE STORMS ARE POSSIBLE WITH WINDS BEING THE PRIMARY THREAT AND
HAIL AS THE SECONDARY.
ONCE THE LINE OF STORMS OVER LAKE MICHIGAN MOVES THROUGH, DRY
CONDITIONS ARE LARGELY EXPECTED OVERNIGHT. SOME SHOWERS MAY LINGER
TOWARD US-10 OVERNIGHT.
- ADDITIONAL THUNDERSTORM CHANCES LATE WEEK
WE REMAIN IN THE NORTHWEST FLOW WITH A COUPLE WEAK SHORTWAVE
TROUGHS MOVING THROUGH TUESDAY/TUESDAY NIGHT AND THEN AGAIN
WEDNESDAY NIGHT INTO THURSDAY. THE LOW LEVEL JET NOSES IN TUESDAY
NIGHT, BUT MOISTURE IS LACKING. BETTER MOISTURE IS PRESENT
WEDNESDAY NIGHT INTO THURSDAY WITH SHOWERS AND STORMS EXPECTED TO
CONTINUE OFF AN ON THROUGH THE REMAINDER OF THE WEEK AS A BOUNDARY
STALLS OVER THE AREA. THIS MATCHES UP WITH THE NBM POPS OF 30 TO
50 PERCENT.
TEMPERATURES DURING THIS TIME WILL BE IN THE 70S TO LOW 80S WITH
LOWS IN THE 50S. FRIDAY LOOKS TO BE THE COOLEST DAY OF THE WEEK
WITH AREAS NORTH OF I-96 POTENTIALLY REMAINING IN THE 60S.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 1245 PM EDT MON JUN 9 2025
THE MAIN FOCUS OF THIS SET OF FORECASTS WILL BE ON THE CONVECTION
EXPECTED TO DEVELOP THIS AFTERNOON AND MOVE THROUGH BY MID
EVENING. MID CLOUDS HAVE MOVED OVER MOST OF THE TERMINALS EARLY
THIS AFTERNOON, ALL VFR IN NATURE SO FAR. WE ARE EXPECTING SHOWERS
AND STORMS TO BEGIN DEVELOPING TOWARD 19Z ALONG THE LAKESHORE, AND
THEN BECOMING MORE WIDESPREAD AND MOVING EAST THROUGH ABOUT 01-02Z
THIS EVENING. CONDITIONS UNDER THE CONVECTION ARE LIKELY TO DROP
TO IFR. FURTHER INLAND WILL HAVE A BETTER CHANCE OF MORE WIND GUST
POTENTIAL AS THE STORMS ORGANIZE AWAY FROM LAKE MICHIGAN.
ONCE THE STORMS MOVE EAST OF THE AREA, WE SHOULD SEE SOME CLEARING
TAKE PLACE, BUT SCATTERED CLOUDS WILL REMAIN THROUGH THE NIGHT.
THESE SHOULD BE VFR. FOG POTENTIAL IS NOT ZERO WITH THE RAINFALL
EXPECTED, BUT A PERSISTENT WIND STAYING UP THROUGH THE NIGHT
SHOULD MITIGATE THE POTENTIAL ENOUGH TO KEEP OUT OF THE FORECAST
FOR NOW.
WE WILL SEE MORE EXTENSIVE CLOUD COVER DEVELOP BY 14-15Z TUESDAY
AS WIDESPREAD CUMULUS/STRATOCUMULUS DEVELOPS. A SPRINKLE OR LIGHT
SHOWER IS NOT OUT OF THE QUESTION.
MARINE
ISSUED AT 253 PM EDT MON JUN 9 2025
SCATTERED THUNDERSTORMS THIS AFTERNOON COULD BRING GUSTY WINDS AND
HAIL. ONCE STORMS PASS DRY CONDITIONS ARE EXPECTED UNTIL
WEDNESDAY NIGHT. WINDS MAY APPROACH SMALL CRAFT ADVISORY RIGHT
ALONG THE SHORELINE THIS AFTERNOON, BUT THE COLDER WATER
TEMPERATURES SHOULD KEEP MOST OF THESE GUSTS AT BAY.
WINDS LOOK TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS AND IN TURN
WAVE HEIGHTS ARE EXPECTED TO BE AROUND 3 FEET OR LESS THROUGH THE
REMAINDER OF THE WEEK.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...NONE.
DISCUSSION...RAH
AVIATION...NJJ
MARINE...RAH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page