808
FXUS63 KGRR 231807
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
207 PM EDT THU JUL 23 2026
KEY MESSAGES
- DRY THROUGH SATURDAY WITH GRADUALLY INCREASING TEMPERATURES
- MULTIPLE CHANCES FOR STORMS SATURDAY NIGHT THROUGH MONDAY
- COOLING OFF MID-WEEK NEXT WEEK AND DRYING OUT
DISCUSSION
ISSUED AT 254 AM EDT THU JUL 23 2026
- DRY THROUGH SATURDAY WITH GRADUALLY INCREASING TEMPERATURES
FORECAST REMAINS UNCHANGED THROUGH SATURDAY, WITH DRY WEATHER
EXPECTED AND INCREASINGLY WARMER TEMPERATURES.
CONFLUENT FLOW ALOFT DOWNSTREAM OF THE UPPER RIDGE OVER THE PLAINS
WILL DOMINATE THE WEATHER THROUGH FRIDAY. THIS SCENARIO PROVIDES FOR
A STRONG SFC RIDGE AXIS REMAINING OVER THE AREA THROUGH FRIDAY ALSO.
ONE SMALL INTERESTING FEATURE IS THE EURO AND HRRR KEEP SHOWING A
FEW SPRINKLES THIS MORNING NEAR THE LAKESHORE. THIS LOOKS TO BE THE
RESULT OF OF A LAND BREEZE CONVERGENT BAND OVER THE LAKE, WITH THE
WARMER LAKE CONTRIBUTING SOME MOISTURE. THIS SHOULD NOT BE ANYTHING
MORE THAT SPRINKLES, AND SURELY NOT IMPACTFUL.
WE WILL SEE THE SFC RIDGE AXIS WEAKEN AND SINK SOUTH OF THE AREA ON
SATURDAY. THIS WILL ALLOW FOR AN INCREASE IN THE LOW LEVEL FLOW FROM
THE SW. ALL INDICATIONS ARE THAT THERE IS NOT MUCH MOISTURE YET
ADVECTING IN, AND NO FEATURE YET TO TRIGGER ANYTHING THROUGH THE
DAYLIGHT HOURS.
- MULTIPLE CHANCES FOR STORMS SATURDAY NIGHT THROUGH MONDAY
THE MODELS AND THEIR ENSEMBLE MEMBERS HAVE BEEN FAIRLY CONSISTENT IN
BRINGING THE FIRST CHANCES OF RAIN TO THE AREA SATURDAY NIGHT. WE
SEE BETTER MOISTURE ABLE TO START ADVECTING IN, AND WE HAVE A SHORT
WAVE RIDING NORTH OF THE AREA TO HELP BRING SOME FORCING TO INTERACT
WITH INCREASING INSTABILITY. THERE IS NOT SHOWN TO BE MUCH OF A LOW
LEVEL JET, WHICH WOULD LIMIT RAIN CHANCES.
RAIN CHANCES LOOK TO BE BETTER SUNDAY NIGHT AND EARLY MONDAY MORNING
IN GENERAL ACROSS THE REGION. THERE IS GOOD AGREEMENT THAT WE SEE A
BETTER ORGANIZED LOW LEVEL JET EXPECTED TO MOVE OVER THE AREA, ALONG
WITH PLENTY OF INSTABILITY IN PLACE. THE BETTER CHANCES FOR RAIN ARE
LIKELY TO BE OVER NORTHERN MICHIGAN AND CANADA WHERE THE NOSE OF THE
LOW LEVEL JET WILL BE. WE SHALL SEE THOUGH WHERE IT ENDS UP, AS IT
COULD PROPAGATE A LITTLE FURTHER SOUTH.
THE POTENTIAL OF CONVECTION THEN MONDAY WILL BE MODULATED BY THE
MOVEMENT OF THE STORMS EARLIER IN THE DAY, AND ANY OUTFLOW
BOUNDARIES THAT MAY BE FLOATING AROUND. AREAS THAT ARE NOT AS MUCH
IMPACTED BY ANY EARLY MORNING STORMS WILL HAVE A CHANCE TO
DESTABILIZE THEN WITH THE HEATING OF THE DAY. THIS COULD LEAD TO
SOME POSSIBLE STRONG TO SEVERE STORMS WITH SOME BETTER MID LEVEL
FLOW HELPING WITH DEEP LAYER SHEAR. THE SHORT WAVE IS FORECAST TO
STAY MAINLY NORTH OF THE AREA, WHICH WOULD LIMIT THE SEVERE
POTENTIAL SOME. WE WILL CONTINUE TO WATCH THE TRENDS WITH THIS.
- COOLING OFF MID-WEEK NEXT WEEK AND DRYING OUT
THERE MAY BE A LINGERING SHOWER TUESDAY MORNING WITH THE UPPER
TROUGH AXIS REMAINING NEARBY. THIS MOVES OUT ON TUESDAY, AND THEN
ALLOWS LARGE SCALE SUBSIDENCE AND SFC RIDGING TO BUILD DOWNSTREAM OF
THE UPPER RIDGE OVER THE PLAINS ONCE AGAIN. THIS WILL BE SIMILAR TO
THIS WEEK WHERE WE COOL OFF UNDER THE NW FLOW, AND REMAIN DRY. THIS
DRY PERIOD SHOULD GO THROUGH NEXT WEDNESDAY. WE WILL HAVE TO KEEP
OUR EYE OUT ON THE UPPER LOW THAT TRIES TO CUTOFF WITH ENERGY COMING
IN FROM THE NW AND AMPLIFYING THE UPPER FLOW. IF IT CLOSES OFF
EARLIER, IT WOULD MEAN BETTER RAIN CHANCES FOR OUR AREA.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 203 PM EDT THU JUL 23 2026
VFR CONDITIONS WILL DOMINATE THE PATTERN THROUGH THE FORECAST
PERIODS. STILL EXPECTING WINDS TO GO CALM THIS EVENING. WILL WILL
MIX OUT TOMORROW MORNING BUT SHOULD REMAIN 5 KTS OR LESS.
MARINE
ISSUED AT 254 AM EDT THU JUL 23 2026
WINDS AND WAVES CAME DOWN SUFFICIENTLY LAST EVENING TO ALLOW THE
HEADLINES TO EITHER BE CANCELLED A TAD EARLY, OR EXPIRE ON TIME.
WE ARE NOW IN A PERIOD OF LIGHTER WINDS WITH HIGH PRESSURE NEARBY
THROUGH FRIDAY. DIURNAL CYCLE OF LAKE BREEZES CAN BE EXPECTED
THROUGH THAT TIME.
WINDS WILL START TO INCREASE A BIT ON SATURDAY WITH WINDS FROM THE
SW OUT AHEAD OF THE NEXT SYSTEM MOVING IN. NOT SURE THEY WILL BE
STRONG ENOUGH TO NEED A HEADLINE, BUT WILL CONTINUE TO WATCH. MONDAY
LOOKS MORE LIKELY THAT HEADLINES WILL BE NEEDED AT THAT TIME.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...NONE.
DISCUSSION...DUKE
AVIATION...CERU
MARINE...DUKE
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