455
FXUS63 KGRR 291746
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
146 PM EDT WED APR 29 2026
KEY MESSAGES
- SCATTERED SHOWERS TODAY AND THURSDAY
- RELATIVE LULL FRIDAY THROUGH SATURDAY
- MORE UNSETTLED NEXT WEEK WITH HIGHER CHANCES FOR RAIN
DISCUSSION
ISSUED AT 308 AM EDT WED APR 29 2026
- SCATTERED SHOWERS TODAY AND THURSDAY
WE HAVE NOW COMPLETED THE PATTERN SHIFT FOR THE CONUS TO THAT OF
STRONG RIDGING BUILDING ALONG THE WESTERN U.S. COAST, AND AN UPPER
LOW CLOSING OFF JUST NORTH OF THE U.S./CANADIAN BORDER BORDER. WHAT
WE HAVE HERE IS A RETURN TO THE PATTERN FROM THIS PAST WINTER WITH
THE UPPER FLOW FROM THE W/NW, NOW COMBINED WITH THE LATE APRIL
TENDENCY FOR UPPER LOWS TO CUT OFF AND A STRONGER SUN ANGLE.
WE WILL SEE CHANCES FOR SCATTERED SHOWERS EACH OF THE NEXT COUPLE OF
DAYS WE HAVE A COUPLE OF DECENT UPPER SHORT WAVES AIMED AT OUR AREA.
THESE SHORT WAVES ARE OF DECENT STRENGTH, BUT DO NOT HAVE ANY GOOD
MOISTURE TO WORK WITH AT THIS TIME. THE BEST CONCENTRATION OF
SHOWERS WILL BE DURING THE DAYLIGHT HOURS, AS THE SUN CONTRIBUTES TO
SOME DIURNAL INSTABILITY. THE THUNDER CHANCES LOOK LOW ENOUGH TO
LEAVE OUT OF THE FORECAST AT THIS TIME.
- RELATIVE LULL FRIDAY THROUGH SATURDAY
WE WILL KEEP THE LOWER HEIGHTS AND COLD POOL ALOFT OVER THE AREA FOR
THE FORESEEABLE FUTURE. IN THE LARGE PICTURE, WE SEE A BLOCKING
PATTERN TAKING SHAPE IN THE FOR OF AN OMEGA AND REX BLOCK. THE OMEGA
BLOCK IS MADE UP OF LOWS OVER THE PACIFIC AND THE UPPER MIDWEST.
THIS WILL CONTINUE THE WAVE TRAIN ROTATING THROUGH, ALTHOUGH THEY
WILL NOT BE AS DIRECT ON OUR AREA, AND SHOULD ALLOW FOR MAINLY DRY
CONDITIONS FRIDAY AND SATURDAY. WE CAN NOT RULE OUT A BRIEF SHOWER,
BUT DRY WEATHER WILL DOMINATE THURSDAY AND FRIDAY. FRIDAY WILL BE
COOL WITH HIGHS POSSIBLY REMAINING IN THE 40S.
ONE THING FOR THURSDAY AND FRIDAY IS THERE MAY BE A POTENTIAL FOR
EACH OF THESE NIGHTS FOR SOME FROST, OR EVEN A FREEZE. WE WILL BE
WATCHING FOR THOSE, AND ISSUE HEADLINES ACCORDINGLY.
- MORE UNSETTLED NEXT WEEK WITH HIGHER CHANCES FOR RAIN
WE WILL BECOME UNDER BETTER INFLUENCE OF THE UPPER LOW EARLY TO MID
WEEK NEXT WEEK ONCE AGAIN, WITH RAIN CHANCES INCREASING ACCORDINGLY.
THE UPPER LOW ONCE AGAIN STAYS OVER OUR AREA, AND BECOMES MORE
FAVORABLE FOR DIURNAL SHOWER ACTIVITY ONCE AGAIN.
WE WILL SEE THE SHORT WAVES MOVE THROUGH ONCE AGAIN BEGINNING LATE
SUNDAY, AND GOING THROUGH MID WEEK NEXT WEEK. THESE WAVES ARE
EXPECTED TO BE A BIT MORE FAVORABLE FOR RAIN FOR A COUPLE OF
REASONS. THE FIRST BEING THE SYSTEMS BEING A BIT STRONGER IN THE
FLOW, ALMOST CLOSING OFF AS THEY APPROACH MICHIGAN. THE SECOND ITEMS
IS THAT WITH THE SYSTEMS BEING STRONGER, THEY WILL HAVE BETTER
OPPORTUNITY TO TAP MOISTURE FROM THE GULF.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 142 PM EDT WED APR 29 2026
LIGHT RAIN ASSOCIATED WITH AN UPPER TROUGH MOVING THROUGH THE
REGION WILL CONTINUE TO FALL THIS AFTERNOON BEFORE ENDING LATE IN
THE DAY. IFR CIGS ARE EXPECTED OVERNIGHT DUE TO ABUNDANT LOW
LEVEL MOISTURE. SOME IMPROVEMENT IS EXPECTED THURSDAY MORNING AS
SLIGHTLY DRIER AIR ADVECTS IN FROM THE WEST.
MARINE
ISSUED AT 308 AM EDT WED APR 29 2026
THE POTENTIAL FOR MARINE HEADLINES OVER THE NEXT FEW DAYS IS ON THE
LOWER SIDE. EVEN THOUGH WE WILL BE IN AN UNSETTLED WEATHER PATTERN
WITH MANY MINI-LOWS/WAVES, THE PRESSURE GRADIENT DOES NOT LOOK
STRONG ENOUGH AT THIS TIME TO REQUIRE HEADLINES.WE WILL SEE PERIODS
WHERE WINDS MAY GET UP TO 20 KNOTS, AND CORRESPONDING WAVES AT 2-3
FEET, BUT NOTHING TOO STRONG AT THIS TIME.
GRR WATCHES/WARNINGS/ADVISORIES
MI...FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR MIZ038>040-045.
FROST ADVISORY FROM 2 AM TO 9 AM EDT THURSDAY FOR MIZ044-046-051-
052-057>059-065-066.
MARINE...NONE.
DISCUSSION...NJJ
AVIATION...04
MARINE...NJJ
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