999
FXUS63 KGRR 091800
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
200 PM EDT FRI OCT 9 2026
KEY MESSAGES
- SHOWER CHANCES TONIGHT WITH WARM AND BREEZY WEATHER SATURDAY
- VERY LITTLE RAIN EXPECTED FOR THE AREA WITH THE REMNANTS OF ISAIAS
- UNSETTLED WEATHER LIKELY TUE AND BEYOND WITH A STRONG STORM SYSTEM
DISCUSSION
ISSUED AT 200 PM EDT FRI OCT 9 2026
- SHOWER CHANCES TONIGHT WITH WARM AND BREEZY WEATHER SATURDAY
WE CONTINUE TO EXPECT A SHORT WINDOW FOR ANY ONE LOCATION OF THE
THREAT OF A SHOWER OR TWO FROM MID-EVENING INTO THE OVERNIGHT HOURS
TONIGHT. REGIONAL SATELLITE AND RADAR IMAGERY SHOWS THE ACTIVE
FRONTAL ZONE TO OUR SW THIS AFTERNOON NEAR THE MISSISSIPPI RIVER
VALLEY NEAR THE MN/IA/WI BORDER.
THERE IS LIGHTNING CURRENTLY ASSOCIATED WITH THE RAIN OUT THERE, BUT
WE REMAIN CONFIDENT THAT THE THREAT OF LIGHTNING HERE WILL BE
ISOLATED AT MOST, AND NOT EVEN ENOUGH TO MENTION AT THIS TIME. MODEL
PROGS SHOW THE SFC BASED AND ELEVATED INSTABILITY EXPECTED TO
DIMINISH TOWARD EVENING, AND RIDE ALMOST DUE NORTH, STAYING WEST OF
OUR AREA. WE MAY SEE A 200 J/KG OF MU CAPE AND LI'S BOTH SFC BASED
AND ALOFT STAYING ABOVE 0C.
SOME OF THE RAIN IS LIKELY TO MAKE IT TO THE GROUND, BUT THAT WILL
BE MAINLY UNDER THE HEAVIER SHOWERS WITH MOISTURE QUITE LIMITED
BELOW 6K FT. ALL OF THIS SHOULD MOVE OUT OF THE AREA PRIOR TO
DAYBREAK ON SATURDAY AS THE WARM FRONT PASSES BY, AND THE NOSE OF
THE LOW LEVEL JET MOVES OUT.
THIS WILL SET THE ENTIRE AREA UP FOR A WARM OCTOBER DAY WITH PLENTY
OF SUNSHINE AND BREEZY CONDITIONS.
- VERY LITTLE RAIN EXPECTED FOR THE AREA WITH THE REMNANTS OF ISAIAS
CLOUDS ON THE LEADING EDGE OF WHAT IS LEFT OF ISAIAS WILL STREAM IN
SATURDAY NIGHT FROM THE SSE. BY 12Z SUNDAY, SOME RAIN WILL LIFT UP
INTO THE AREA, MAINLY SE OF GRAND RAPIDS. THE SE TREND HAS CONTINUED
EVEN A LITTLE BIT MORE OVER THE LAST 24 HOURS, DUE TO THE LOGJAM OF
SYSTEMS TO THE NW. WHAT RAIN THERE WILL BE WILL BE LIGHT ON AMOUNTS,
WITH MOST OF THE AREA THAT SEES RAIN STAYING UNDER A TENTH OF AN
INCH. OF COURSE SOME LOCALLY HIGHER AMOUNTS WILL BE POSSIBLE.
THE CLOUDS AND RAIN WILL MOVE OUT BY MONDAY, AS THE UPPER TROUGH OUT
WEST, AND UPPER RIDGE IMMEDIATELY WEST OF OUR AREA PUSHES OVER THE
AREA. MONDAY IS SHAPING UP TO BE ANOTHER WARM DAY LIKE SATURDAY WITH
A GOOD WARM FLOW FROM THE SW MOVING IN AHEAD OF THE NEXT FRONT.
- UNSETTLED WEATHER LIKELY TUE AND BEYOND WITH A STRONG STORM SYSTEM
MONDAY MAY BE THE LAST NICE FALL DAY FOR A FEW DAYS, AS WE ARE
EXPECTED TO BECOME UNDER THE INFLUENCE OF A MUCH MORE ACTIVE AND
UNSETTLED PATTERN FOR TUESDAY AND BEYOND.
THE LARGE LONG WAVE TROUGH OUT WEST WILL BE TRYING TO PUSH EAST ONCE
ISAIAS MOVES OUT OF THE WAY THIS WEEKEND. STRONG RIDGING OVER THE
SOUTHERN STATES WILL HOLD BACK THE SOUTHERN PART OF THE RIDGE, WHILE
ENERGY FLATTENS OUT THE TOP OF THE RIDGE A BIT. THIS WILL ALLOW A
COLD FRONT TO SINK SOUTH OVER THE AREA ON TUESDAY. MOISTURE IS
INITIALLY A BIT LIMITED AS THE FRONT MOVES THROUGH. THE FRONT STALLS
OUT, AND ADDITIONAL SHORT WAVES ARE EXPECTED TO RIDE ALONG THIS.
THESE WAVES WILL HELP PRODUCE SHOWERS AND STORMS WITH SURGES OF LOW
LEVEL MOISTURE RIDING OVER THE FRONT AHEAD OF THE WAVES.
THE LONG WAVE TROUGH/LOW THAT CLOSES OFF OVER THE SW U.S. IS
FORECAST TO LIFT OUT INTO THE PLAINS BY THURSDAY. STRONG LARGE SCALE
FORCING AHEAD OF THIS TROUGH WILL HELP TO DEVELOP A STRONGER FALL
SYSTEM AND LIFT NORTHWARD WEST OF OUR AREA. IF THIS HOLDS, WE WOULD
SEE A STRONG SURGE OF WARM AIR AROUND THURSDAY, WITH LOTS OF GULF
MOISTURE THAT WOULD BRING PLENTY SHOWERS AND STORMS TO THE AREA. ONE
CAN NOT RULE OUT A SEVERE WEATHER EVENT NEXT THU IF THINGS DON'T
CHANGE MUCH WITH THE LOW GOING NEGATIVELY TILTED OVER TIME.
THE FRONT WOULD THEN GO THROUGH AROUND THE FRIDAY TIME FRAME, AND
BRING IN MUCH COLDER AIR WITH STRONGER WINDS. THE NORTHERN BRANCH OF
THE UPPER JET WOULD SINK SOUTH OF OUR AREA, AND BRING A POTENTIAL
FOR LAKE EFFECT RAIN SHOWERS.
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 200 PM EDT FRI OCT 9 2026
AS EXPECTED, WE WILL BE HOISTING A SMALL CRAFT ADVISORY FOR THE
INCREASE IN WIND TONIGHT INTO SATURDAY NIGHT. THE ADVISORY WILL BE
IN EFFECT FROM HOLLAND AND TO THE NORTH WHERE THE BEST WIND WILL BE.
THIS IS MOSTLY A WARM AIR ADVECTION WIND, SO THE FULL EFFECTS WILL
NOT BE REALIZED AT THE SURFACE. THE GRADIENT WILL THEN WEAKEN
SATURDAY NIGHT AS ISAIAS APPROACHES THE AREA BEFORE TURNING AWAY.
THE NEXT HEADLINE EVENT LOOKS TO BEGIN ON MONDAY. THIS WILL BE
INCREASING GRADIENT AHEAD OF THE NEXT INCOMING COLD FRONT COMING IN
FROM THE NW. MUCH OF NEXT WEEK LOOKS WINDY, ESPECIALLY LATER IN THE
WEEK WHEN A STRONGER SYSTEM IS LIKELY TO MOVE OVER THE AREA.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM SATURDAY TO 5 AM EDT SUNDAY FOR
LMZ846>849.
DISCUSSION...NJJ
AVIATION...THOMAS
MARINE...NJJ
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