545
FXUS63 KGRR 280540
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
140 AM EDT MON APR 28 2025
KEY MESSAGES
- ELEVATED FIRE DANGER MONDAY
- STORMS POSSIBLE MONDAY NIGHT INTO TUESDAY
- SHOWERS AND STORMS POSSIBLE WEDNESDAY NIGHT INTO EARLY FRIDAY
DISCUSSION
ISSUED AT 345 PM EDT SUN APR 27 2025
- ELEVATED FIRE DANGER MONDAY
ANOTHER DRY DAY IS EXPECTED ON MONDAY ALTHOUGH WITH WARMER
TEMPERATURES AND STRONGER WINDS THE FIRE DANGER WILL BE ELEVATED.
THERE'S BEEN A FEW REPORTS OF GRASS/FIELD FIRES AROUND THE AREA
TODAY AND SIMILARLY LOW RH VALUES ARE EXPECTED AGAIN ON MONDAY.
PARTICULARLY VULNERABLE WILL BE THE MANISTEE NATIONAL FOREST AREA.
- STORMS POSSIBLE MONDAY NIGHT INTO TUESDAY
THE LATER PERIODS OF THE 12Z CAMS ARE NOT VERY AMBITIOUS WITH
CONVECTION ON MONDAY AND MONDAY NIGHT, BOTH IN THE SPC MDT RISK AREA
TO THE WEST AS WELL AS IN WRN LWR MI. THIS COULD BE RELATED TO AN
UNFAVORABLE/DIVERGENT LOW LEVEL JET ORIENTATION AND/OR CONVECTIVE
INHIBITION ARRIVING WITHIN THE WARM SECTOR.
THAT SAID THE GENERAL SYNOPTIC SETUP FOR STRONG TO SEVERE STORMS IS
PRESENT OVER WRN LWR MI LATER MONDAY NIGHT WITH DEEP LAYER SHEAR
OF GREATER THAN 35 KTS, MUCAPES NEAR 1500 J/KG, AND A COLD FRONT
LEANING IN FROM THE NORTHWEST.
CAMS DO SEEM TO AGREE ON A LINE OF ORGANIZED CONVECTION IN NRN WI
MONDAY EVENING AND THAT MAY TURN/DIVE SOUTH-SOUTHEAST TOWARD WRN LWR
MI ALONG THE INSTABILITY GRADIENT OVERNIGHT. DEEP LAYER THICKNESS
PROGS WOULD ALSO SUPPORT SOUTHWARD PROPAGATING CONVECTION OVERNIGHT
SHOULD A DECENT COLD POOL/MATURE MCS DEVELOP UPSTREAM AND SURVIVE
DEEPER INTO THE NIGHT.
THERE IS STILL A LOW POTENTIAL FOR NEW/DIURNAL CONVECTION TO DEVELOP
TUESDAY ALONG THE COLD FRONT OR OLD CONVECTIVE OUTFLOW BOUNDARY
BEFORE IT EXITS, ESPECIALLY SOUTH AND EAST OF GRR, BUT THE MAIN
SEVERE WEATHER RISK IS SOUTH AND EAST OF MICHIGAN. ANOTHER
AREA/LINE OF SHOWERS AND STORMS COULD DEVELOP LATER IN THE DAY
TUESDAY WELL BEHIND/NORTH OF THE DEPARTING FRONT WITH AN H5
SHORTWAVE COMING IN FROM THE NORTHWEST.
- SHOWERS AND STORMS POSSIBLE WEDNESDAY NIGHT INTO EARLY FRIDAY
THE SYSTEM ON THURSDAY IS RAMPING UP IN TERMS OF POPS AND QPF AS A
SHORTWAVE AND ITS SFC REFLECTION TRACKS NORTHEAST ALONG THE
FRONTAL BOUNDARY SOUTH OF MI. THERE COULD BE A FEW STRONGER STORMS
LATER THURSDAY SHOULD THE SFC LOW TRACK FARTHER NORTH AND PULL
THE WARM FRONT INTO SRN LWR MI SO THAT WILL NEED WATCHED. THAT
SYSTEM IS FOLLOWED BY UPPER TROUGHING AND COOLER AIR ON FRIDAY
BEFORE HIGH PRESSURE MOVES IN FOR SATURDAY.
NEWER GUIDANCE IS PLACING MI MORE IN THE RIDGY PORTION OF THE
DEVELOPING OMEGA BLOCKING PATTERN FOR NEXT WEEKEND INDICATING DRY
AND PLEASANT WEATHER. HOWEVER A FEW MEMBERS/CLUSTERS STILL SUGGEST A
FARTHER WEST POSITION OF THE NEW ENGLAND TROUGH WHICH WOULD KEEP US
THE COOLER SIDE.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 140 AM EDT MON APR 28 2025
FEW TO SCT CLOUDS AROUND 11,000 FEET ARE CURRENTLY MOVING THROUGH
THE AREA AND WILL CLEAR LATER THIS MORNING. SOUTHERLY WINDS WILL
BUILD WITH GUSTS AROUND 20 TO 30 KNOTS ACROSS THE AREA. THIS
EVENING WINDS WILL REMAIN AROUND 15 KNOTS WITH LOW LEVEL WIND
SHEAR DEVELOPING LATE TONIGHT ACROSS THE AREA AS THE LOW LEVEL JET
MOVES IN FROM THE WEST.
MARINE
ISSUED AT 345 PM EDT SUN APR 27 2025
INCREASING SOUTHERLY FLOW MONDAY ON THE BACK SIDE OF A DEPARTING
SFC HIGH LEADS TO HAZARDOUS WINDS AND WAVES DEVELOPING; INITIALLY
NORTH OF GRAND HAVEN MONDAY MORNING THEN OVER THE REST OF THE
NEARSHORE BY MONDAY EVENING. HAZARDOUS WINDS AND WAVES CONTINUING
INTO MONDAY NIGHT AND TUESDAY WITH A COLD FRONTAL PASSAGE BRINGING
THE THREAT FOR A FEW STRONG TO SEVERE STORMS AND A WIND SHIFT.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 8 PM EDT
TUESDAY FOR LMZ844>846.
SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 8 PM EDT TUESDAY
FOR LMZ847>849.
DISCUSSION...MEADE
AVIATION...RAH
MARINE...MEADE
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page