634
FXUS63 KGRR 021913
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
313 PM EDT THU JUL 2 2026
KEY MESSAGES
- HEAT RISK GRADUALLY DIMINISHES
- CHANCES FOR STORMS CONTINUE THROUGH THE HOLIDAY WEEKEND
DISCUSSION
ISSUED AT 313 PM EDT THU JUL 2 2026
- HEAT RISK GRADUALLY DIMINISHES
SUBSIDENCE AND DRYING FROM THIS MORNING'S DYING CONVECTIVE SYSTEM
HAS LEFT BEHIND DEW POINTS IN THE MID 60S IN CENTRAL MI, WHILE
CLOSER TO I-94, DEW POINTS ARE STILL IN THE MID 70S WITH HEAT
INDEXES AROUND 100. WITH THE EXCEPTION OF LUDINGTON, IT'S STILL
HOT, BUT THE SOMEWHAT DRIER AIR GIVES AN OPPORTUNITY TO CHISEL
AWAY AT THE EXTREME HEAT WARNING ALONG AND NORTH OF A MUSKEGON TO
CLARE LINE. THE REMAINING WARNING WILL TURN OVER TO A HEAT
ADVISORY THIS EVENING THROUGH FRIDAY MORNING AS MODERATE TO HIGH
HEAT RISK CONTINUES AS THE HEAT WAVE POTENTIALLY STRETCHES INTO A
FIFTH DAY IN SOUTHERN PORTIONS OF MICHIGAN. WHILE SOME NOTICEABLE
HUMIDITY WILL REMAIN, MODELS ARE LOCKED IN ON TEMPERATURES
TRENDING CLOSER TO NORMAL BY EARLY NEXT WEEK, GIVEN THE WEAKENING
OF THE SE US HEAT DOME AND A TENDENCY FOR WEAK UPPER LEVEL
TROUGHING OVER THE GREAT LAKES.
- CHANCES FOR STORMS CONTINUE THROUGH THE HOLIDAY WEEKEND
UNSETTLED WEATHER CONTINUES WITH FAIRLY LOW CONFIDENCE IN THE
PREDICTABILITY OF THUNDERSTORMS GIVEN WEAK FORCING MAINLY DRIVEN
BY UPSTREAM CONVECTIVE COMPLEXES AND THEIR ASSOCIATED INDUCED
ATMOSPHERIC WAVES. THE DRIER AIR AND STRONG CAP PRESENT THIS
EVENING WILL KEEP THE CHANCE OF STORMS VERY LOW, THOUGH CAN'T RULE
OUT A SHOWER POPPING UP NEAR BATTLE CREEK OR JACKSON. THE STORM
COMPLEX IN EASTERN IOWA WILL TRACK TOWARD WEST/SOUTHWEST MICHIGAN
FOR LATE THIS EVENING/TONIGHT, THOUGH ITS INTENSITY WHEN IT
ARRIVES IS VERY MUCH IN QUESTION. ANY THREAT WOULD PRIMARILY BE
WIND, AS THERE WILL BE WEAK CLOUD-LAYER SHEAR BUT SUBSTANTIAL
DCAPE.
THE CHANCES FOR ADDITIONAL STORMS REMAINS FOR FRIDAY
AFTERNOON/EVENING, PARTICULARLY IN SOUTHERN MICHIGAN, FOLLOWED BY
SCATTERED STORMS POPPING UP THROUGH THE REMAINDER OF THE WEEKEND
AS A LARGER-SCALE WEAK UPPER LEVEL TROUGH DEEPENS OVER THE GREAT
LAKES. A MAJORITY MEMBERS OF THE ECE AND GEFS ARE FAIRLY BULLISH
ON THE PRECIP CHANCES THROUGH AT LEAST SATURDAY NIGHT.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 100 PM EDT THU JUL 2 2026
THE NEXT SIX HOURS WILL FEATURE VFR CONDITIONS AS DAYTIME CU
DEVELOP IN THE 3-4KFT RANGE, WITH BKN CIGS POSSIBLE AT JXN/BTL.
AFTER 00Z, ATTENTION TURNS TO CONVECTIVE POTENTIAL HOWEVER
CONFIDENCE IS LOW IN HOW CONVECTIVE DEVELOPMENT EVOLVES AND SHORT
RANGE MODEL GUIDANCE REALLY STRUGGLES ON COVERAGE AND PLACEMENT SO
HAVE MAINTAINED PROB30S FOR TSRA. THERE HAS BEEN A BIT OF A LATER
TREND IN THUNDERSTORM TIMING WITH 02-10Z AS THE FAVORED WINDOW
BASED ON HRRR/RRFS/REFS/FV3 GUIDANCE. MVFR AND LOWER CONDITIONS
AND GUSTS IN EXCESS OF 40 KNOTS ARE POSSIBLE IN ANY CONVECTION
THAT DEVELOPS. LOOK FOR GUSTY WINDS TO AROUND 25 KNOTS THIS
AFTERNOON DIMINISHING TONIGHT.
MARINE
ISSUED AT 313 PM EDT THU JUL 2 2026
MOSTLY A LIGHTER SOUTH/SOUTHWEST FLOW OVER THE LAKE HAS KEPT US
OUT OF BEACH HAZARDS TODAY. SMALLER ZONES OF 15 KNOT WINDS OVER
THE LAKE COULD BUILD WAVES TO 2 TO 4 FEET WITH A MODERATE SWIM
RISK THIS AFTERNOON BETWEEN MUSKEGON AND LUDINGTON. OTHERWISE,
OUTSIDE OF ANY THUNDERSTORMS, A LIGHTER WIND REGIME THROUGH THE
HOLIDAY WEEKEND WILL KEEP WAVE HAZARDS LOW.
THERE IS A CHANCE OF SCATTERED THUNDERSTORMS CROSSING THE LATE
TONIGHT AND AGAIN LATER IN THE DAY FRIDAY. WIND GUSTS AND
LIGHTNING WILL BE THE MAIN THREATS.
GRR WATCHES/WARNINGS/ADVISORIES
MI...EXTREME HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR MIZ046-051-
052-056>059-064>067-071>074.
HEAT ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT FRIDAY FOR
MIZ046-051-052-056>059-064>067-071>074.
MARINE...NONE.
DISCUSSION...CAS
AVIATION...THOMAS
MARINE...CAS
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