927
FXUS63 KGRR 091621
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1221 PM EDT FRI OCT 9 2026
KEY MESSAGES
- LIGHT RAIN POSSIBLE TONIGHT
- ISAIAS COULD BRING SOME SHOWERS SUNDAY
- PATTERN CHANGE WITH COLD FRONT MONDAY INTO TUESDAY
DISCUSSION
ISSUED AT 258 AM EDT FRI OCT 9 2026
- LIGHT RAIN POSSIBLE TONIGHT
A NEGATIVELY TILTED MID LEVEL RIDGE WILL BY DRIVING TO THE EAST
BY AN APPROACHING UPPER LEVEL SYSTEM MOVING THROUGH WESTERN
CANADA. THIS WILL BRING SOME WARM AIR ADVECTION INTO MICHIGAN LATE
TODAY THROUGH SATURDAY. GIVEN THAT WARM AIR ADVECTION, THERE
COULD BE ENOUGH MOISTURE AND LIFT TO BRING SOME LIGHT RAIN THIS
EVENING. THE WARM AIR ADVECTION WILL SEND MAX TEMPS BETWEEN 10 TO
15 DEGREES ABOVE NORMAL THROUGH THE WEEKEND AND INTO MONDAY. WHILE
CLEAR SKIES DURING THE EVENING WILL LEAD TO SOME CRISP MORNINGS,
SATURDAY COULD SEE TEMPS IN THE MID TO UPPER 70S. IF SKIES CLEAR
THERE IS A CHANCE TO REACH 80.
- ISAIAS COULD BRING SOME SHOWERS SUNDAY
THE NEXT CHANCE FOR ANY APPRECIABLE RAIN WILL BE FROM THE
REMNANTS OF ISAIAS SUNDAY. WHILE ITS NOT TO PROPHETICAL TO SAY,
THE BEST CHANCE FOR RAIN ON SUNDAY WILL BE THROUGH THE EASTERN
HALF OF THE STATE.
MODELS ARE FAIRLY CONSISTENT, THOUGH IT HAS TRENDED EASTWARD,
AND THE TRACK WITH NHC HAVING IT MOVING THROUGH KY AS A DEPRESSION
SUNDAY. EXPECT INCREASE CLOUDS WITH SHOWERS ALONG AND EAST OF THE
US 127 CORRIDOR. THE RIDGE OF HIGH PRESSURE TO ITS WEST,
CORRELATED WITH DEEPENING LOW OVER THE WEST COAST WILL KEEP ISAIAS
FROM SHIFTING TO THE WEST.
THE WARM AIR WILL CONTINUE TO DOMINATE THE AREA THROUGH MONDAY
WITH HIGHS CONTINUING IN THE 70S.
- PATTERN CHANGE WITH COLD FRONT MONDAY INTO TUESDAY
A COLD FRONT IS STILL ON TRACK TO SWING THROUGH THE AREA LATE
MONDAY INTO TUESDAY. WHILE QPF REMAINS SPOTTY, THE FLOW WILL SHIFT
TO THE NORTHWEST AND BRING TEMPERATURES DOWN CLOSER TO NORMAL. SO
ENJOY THE WARMTH AS AUTUMN AWAITS YOU THROUGH THE LATTER HALF OF
THE UPCOMING WEEK. THAT SAID, LOWS WILL ONLY DROP INTO THE 40S
THROUGH MUCH OF THE REGION.
THE NEXT SYSTEM TO KEEP AN EYE OUT FOR WILL BE PREVIOUSLY
MENTIONED LOW OVER THE WEST COAST. THAT WILL TREK ACROSS THE
STATES THROUGH THE WEEK AND IS CURRENTLY TRENDING AN ARRIVAL TIME
ON THURSDAY. THERE IS QUITE A BIT OF DIFFERENCE E ON THE
POSITION OF THE LOWS AND ITS ORIENTATION. GIVEN THAT CONFIDENCE
IS LOW ON WHEN IT WILL ARRIVE AND HOW MUCH QPF WILL BE ASSOCIATED
WITH IT WHEN IT SWINGS THROUGH MICHIGAN. THE GEFS DOES HAVE
ANOMALOUS PWATS UPWARDS OF 1.25 THROUGH THE LOWER PENINSULA
THURSDAY. SO THERE IS THE POTENTIAL FOR WIDESPREAD RAIN THURSDAY.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1221 PM EDT FRI OCT 9 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST
PERIOD, WITH SATELLITE TRENDS SHOWING CIGS LOWERING THROUGH THE
DAY INTO TONIGHT AS A WARM FRONT APPROACHES. HAVE ADJUSTED CIGS
UPWARD OVERNIGHT BASED ON THE LATEST PROBABILISTIC GUIDANCE AND
SHORT RANGE BUFKIT OVERVIEWS WITH SOLIDLY VFR CONDITIONS FAVORED.
MVFR CU BASED CIGS ARE NOT ZERO, BUT CHANCES ARE AOB 20 PERCENT.
LOW CHANCE OF SHOWERS WITH THIS FRONT AS WELL, MAINLY AT MKG.
00Z-06Z WOULD BE THE FAVORED WINDOW, THOUGH ONLY MKG HAS ENOUGH
CHANCES TO WARRANT EVEN A PROB30. OTHERWISE, EXPECT SOUTH TO
SOUTHEAST WINDS OVER THE TAF PERIOD. GUSTS INCREASE TO AROUND 20
KNOTS AT MKG SATURDAY MORNING.
MARINE
ISSUED AT 258 AM EDT FRI OCT 9 2026
LIGHT FLOW WILL CONTINUE THROUGH TODAY INTO TONIGHT WITH LIGHT
EASTERLY FLOW. THE GRADIENT WILL INCREASE TONIGHT INTO SATURDAY
MORNING, THOUGH IT SHOULD REMAIN PRIMARILY OFFSHORE THROUGH
SATURDAY MORNING. THERE IS A CHANCE SOME GUSTS GET INTO SCA
CRITERIA, BUT WINDS AND WAVES WILL REMAIN FLOWING OFFSHORE. AS THE
WARM FRONT PASSES, THE WINDS SHOULD SHIFT TO A SOUTH FLOW BY
MIDDAY SATURDAY. WILL HOLD OFF ON ANY HEADLINES FOR NOW BUT ONE
WILL PROBABLY BE NEEDED SATURDAY INTO SUNDAY.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...NONE.
DISCUSSION...CERU
AVIATION...THOMAS
MARINE...CERU
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