962
FXUS63 KGRR 270619
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
219 AM EDT MON APR 27 2026
KEY MESSAGES
- RAIN AND THUNDERSTORMS MONDAY AFTERNOON INTO MONDAY NIGHT
- COOLER AND MAINLY DRY TUESDAY THROUGH SATURDAY
DISCUSSION
ISSUED AT 235 PM EDT SUN APR 26 2026
- RAIN AND THUNDERSTORMS MONDAY AFTERNOON INTO MONDAY NIGHT
OVERALL DRY CONDITIONS ARE EXPECTED INTO EARLY MONDAY AFTERNOON. A
DECAYING LINE OF THUNDERSTORMS MOVES IN FROM THE SOUTHWEST DURING
THE LATE AFTERNOON. INSTABILITY AND LIFT WILL BE LIMITED OVER THE
AREA. THIS INITIAL ROUND OF RAIN AHEAD OF OUR EVENING ROUND COULD
IMPACT OUR MARGINAL SEVERE RISK. WE'LL HAVE PLENTY OF SHEAR WITH THE
LOW AND MID LEVEL JET, BUT INSTABILITY IS LACKING. HREF KEEPS VALUES
BELOW 1000 J/KG AND DOESN'T BRING IN THE BETTER INSTABILITY UNTIL
THE LINE OF SHOWERS AND THUNDERSTORMS IS ALREADY THROUGH THE
AREA. THIS TIMING DIFFERENCE REALLY LIMITS THE POTENTIAL FOR ANY
STRONGER STORMS. THE BEST WINDOW FOR ANY STRONG TO SEVERE STORMS
WOULD BE BETWEEN 8PM MONDAY AND 2AM TUESDAY. WIND WOULD BE THE
PRIMARY CONCERN LARGELY SOUTH OF I-96 WITH THE BEST CHANCES IN FAR
SOUTHWEST MICHIGAN. THIS AREA IS CONSISTENT BETWEEN THE NCAR,
GEFS, NSSL, NADOCAST, AND SPC OUTLOOKS.
- COOLER AND MAINLY DRY TUESDAY THROUGH SATURDAY
WE'LL REMAIN UNDER TROUGHING THROUGH MOST OF THE WEEK BRINGING
COOLER TEMPERATURES TO THE REGION. A COUPLE SHORTWAVE TROUGHS MAY
SPARK OFF SHOWERS TUESDAY NIGHT INTO WEDNESDAY AND THURSDAY NIGHT
INTO FRIDAY. HIGH TEMPERATURES WILL LARGELY BE IN THE 50S WITH LOWS
IN THE 30S. FROST WILL BE POSSIBLE STARTING WEDNESDAY NIGHT. BE
PREPARED TO TAKE CARE OF ANY SENSITIVE VEGETATION DURING THIS PERIOD
OF COLDER TEMPERATURES.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 219 AM EDT MON APR 27 2026
A LOW PRESSURE SYSTEM WILL TAKE AIM ON THE GREAT LAKES TODAY FROM
THE CENTRAL PLAINS. WE WILL SEE CEILING LOWER THROUGH THE DAY FROM
HIGH CLOUDS THIS MORNING WITH BASES AT OR ABOVE 20,000 FEET
DROPPING INTO THE 5,000 TO 10,000 FOOT RANGE THIS AFTERNOON. SOME
SCATTERED SHOWERS ARE POSSIBLE THIS AFTERNOON IN ADVANCE OF A WARM
FRONT, BUT THE BULK OF THE HEAVIER PRECIPITATION SHOULD HOLD OFF
UNTIL AFTER 00Z. IN THE 00Z TO 06Z TIME FRAME WE WILL SEE SHOWERS
AND THUNDERSTORMS AFFECT THE TAF SITES. CEILINGS WILL ALSO LOWER
FURTHER INTO THE MVFR CATEGORY AND BY THE END OF THE PERIOD
TOWARDS 06Z EVEN IFR CONDITIONS ARE POSSIBLE. BOTTOM LINE, VFR
TODAY WITH CONDITIONS TRENDING WORSE TONIGHT AS A LOW PRESSURE
SYSTEM MOVES THROUGH THE GREAT LAKES.
WIND WILL BE NOTICEABLE AND A CONCERN FOR AVIATION TODAY. WINDS
WILL BE SOUTHEAST INCREASING INTO THE 15-30 KNOT RANGE THIS
AFTERNOON AND EVENING. WINDS WILL VEER TO THE SOUTH OVERNIGHT.
MARINE
ISSUED AT 235 PM EDT SUN APR 26 2026
SOUTHEAST WINDS BUILD TONIGHT INTO MONDAY WITH GUSTS 25 TO 30 KNOTS
MONDAY MORNING. SMALL CRAFT ADVISORY CONDITIONS ARE THEN EXPECTED TO
CONTINUE INTO TUESDAY WITH WINDS BECOMING MORE WESTERLY. WAVE
HEIGHTS BUILD TO 4 TO 8 FEET MONDAY NIGHT AS THE WINDS SHIFT TO
THE SOUTHWEST. THUNDERSTORMS WILL ALSO BE POSSIBLE LATE MONDAY
AFTERNOON INTO MONDAY NIGHT.
WINDS AND WAVES WILL THEN SUBSIDE TUESDAY AFTERNOON AND REMAIN BELOW
SMALL CRAFT ADVISORY CONDITIONS THROUGH THE REST OF THE WEEK.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 PM EDT TUESDAY
FOR LMZ844>849.
DISCUSSION...RAH
AVIATION...DUKE
MARINE...RAH
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