216
FXUS63 KGRR 191745
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
145 PM EDT SUN OCT 19 2025
KEY MESSAGES
- SHOWERS, HEAVY AT TIMES, CONTINUES TODAY
- BRIEF RESPITE LATE TODAY THROUGH MONDAY
- COOL, BREEZY, AND WET MONDAY NIGHT THROUGH THURSDAY
DISCUSSION
ISSUED AT 354 AM EDT SUN OCT 19 2025
- SHOWERS, HEAVY AT TIMES, CONTINUES TODAY
THE LARGE UPPER LEVEL LOW CONTINUES TO BRING WIDESPREAD SHOWERS
AND THROUGH THE REGION. PRECIPITATION REMAINS STEADY WITH POCKETS
OF HEAVIER SHOWERS. THE MAIN AXIS OF HEAVIEST SHOWERS HAS SHIFTED
TO ALONG THE US 127 CORRIDOR AND WILL CONTINUE TO SHIFT EASTWARD.
WHILE THERE HAS BEEN SOME INCREASED SOIL MOISTURE, AND CREST
MAXIMUM UNIT STREAMFLOW THROUGH CENTRAL KENT COUNTY, ONLY PONDING
OF WATER AND PERHAPS VERY LOCALIZED MINOR FLOODING IS EXPECTED.
THERE WILL BE SOME REDUCTIONS IN VISIBILITY FROM FOG DUE TO THE
RAINFALL THIS MORNING.
DRY AIR HAS BEGUN TO INFILTRATE INTO INDIANA, SO WHILE SHOWERS
WILL PERSIST THIS MORNING, THEY WILL LESSEN AND FADE BY THIS
AFTERNOON. ONCE THE TROUGH AXIS MOVES EASTWARD, THE STRONG
NORTHWESTERLY FLOW WILL BRING WINDS UPWARDS OF 35 MPH. WHILE
HIGHER GUSTS ARE POSSIBLE ALONG THE LAKESHORE, HAVE HELD OFF ON A
WIND ADVISORY FOR NOW.
- BRIEF RESPITE LATE TODAY THROUGH MONDAY
WHILE THE RAIN SHOWERS WILL HELP TO CURB ANY DROUGHT CONDITIONS A
RIDGE SANDWICHED BETWEEN TWO UPPER LEVEL LOWS WILL BUILD OVER THE
AREA MONDAY. TEMPERATURES WILL BE AROUND NORMAL WITH HIGHS INTO
THE 60S.
- COOL, BREEZY, AND WET MONDAY NIGHT THROUGH THURSDAY
ANOTHER LOW PRESSURE SYSTEM MOVES INTO THE GREAT LAKES REGION MONDAY
NIGHT INTO TUESDAY BRINGING AN EXTENDED PERIOD OF COOL, BREEZY, AND
WET CONDITIONS.
WARM AIR ADVECTION AND MOISTURE ADVECTION WILL DRIVE THE FIRST ROUND
OF RAIN LATE MONDAY NIGHT INTO EARLY TUESDAY MORNING. THERE COULD BE
A PERIOD OF DRY CONDITIONS TUESDAY MORNING INTO EARLY TUESDAY
AFTERNOON AS LOW TO MID LEVEL MOISTURE DECREASES. LATER TUESDAY
AFTERNOON MOISTURE WRAPS BACK IN AROUND THE LOW BRINGING ANOTHER
ROUND OF SHOWERS. PRETTY GOOD AGREEMENT BETWEEN THE CLUSTER ANALYSIS
FOR AN EXTENDED PERIOD OF SHOWERS INTO THURSDAY AS COLD AIR ADVECTS
IN WITH THE LOW OVER THE WARM WATERS OF LAKE MICHIGAN. LAKE EFFECT
SHOWERS LIKELY CONTINUE THROUGH THURSDAY BEFORE WE SEE HEIGHT RISES
THURSDAY NIGHT INTO FRIDAY MORNING.
WINDS WITH THIS LOW WILL BE BREEZY FROM THE SOUTHWEST MONDAY NIGHT
INTO TUESDAY AND THEN SHIFTING TO THE WEST TO NORTHWEST TUESDAY
NIGHT INTO WEDNESDAY. HOW STRONG THE WINDS WILL BE DEPENDS ON THE
OVERALL STRENGTH OF THE LOW AND WHERE THE CORE OF STRONGER WINDS
ASSOCIATED WITH THE LOW LEVEL JET SET UP. LOOKING AT THE CLUSTER
ANALYSIS MEAN 925MB AND 850MB WINDS THE STRONGEST WINDS ARE EXPECTED
MONDAY NIGHT INTO TUESDAY WHERE VALUES ARE AROUND 35 TO 45 KNOTS.
THEN DROP MORE INTO THE 30 TO 40 KNOT RANGE DURING THE DAY TUESDAY
INTO WEDNESDAY WITH THE STRONGEST WINDS TO OUR SOUTHWEST. IF WE ARE
ABLE TO MIX DOWN THESE STRONGER WINDS ALOFT A WIND ADVISORY MAY BE
NEEDED.
WITH THIS LOW PRESSURE SYSTEM, HIGHS ARE EXPECTED TO BE IN THE UPPER
40S TO 50S THROUGH THE REMAINDER OF THE WEEK WITH LOWS IN THE 30S.
NOW'S THE TIME TO WRAP UP ANY GARDENING IF YOU HAVEN'T DONE SO
ALREADY.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 145 PM EDT SUN OCT 19 2025
MVFR TO IFR CONDITIONS WILL CONTINUE AS RAIN SHIFTS EAST THROUGH
THE AREA EXITING AROUND 21Z-03Z FROM WEST TO EAST. DURING THIS
TIME CEILINGS WILL LIFT AND CLEAR. SOME FEW TO SCT CLOUDS AROUND
4000 TO 6000 FEET MAY LINGER INTO MONDAY MORNING.
NORTHWEST WINDS GUSTING 25 TO 35 KNOTS WILL CONTINUE THROUGH THE
AFTERNOON ON THE BACKSIDE OF THE LOW AND WEAKEN AFTER 00Z. A
PERIOD OF LOW LEVEL WIND SHEAR IS POSSIBLE FOR GRR, AZO, AND BTL
THROUGH 9Z AS WINDS BECOME LIGHT ENOUGH AT THE SURFACE WITH 30
KNOTS SUSTAINED AROUND 2000 FEET. WINDS WILL THEN BE LIGHT AND
FROM THE SOUTHWEST INITIALLY MONDAY BEFORE BUILDING INTO THE
AFTERNOON.
MARINE
ISSUED AT 339 AM EDT SUN OCT 19 2025
NO CHANGES TO THE GALE WARNING. NORTHWEST GALES WILL BUILD THIS
MORNING AND CONTINUE THROUGH THIS AFTERNOON. THE NORTHWEST FLOW
WILL DECREASE BY LATE EVENING. CONDITIONS WILL REMAIN HAZARDOUS
TO SMALL CRAFT THROUGH MONDAY, THEN ANOTHER GALE WARNING WILL
PROBABLY BE NEEDED FOR TUESDAY. AT THIS POINT IT APPEARS THE WINDS
ON TUESDAY MAY ACTUALLY BE STRONGER THAN THOSE ON SUNDAY, WITH
WEST GALES OVER 40 KNOTS POSSIBLE.
HYDROLOGY
ISSUED AT 318 PM EDT FRI OCT 17 2025
SIGNIFICANT RAINFALL IS EXPECTED OVER THE NEXT SEVERAL DAYS ACROSS
MUCH OF LOWER MICHIGAN. THE TOTAL AMOUNT OF RAIN WE ARE EXPECTING
CONTINUES TO SLOWLY NUDGE UPWARDS AS FORECAST DETAILS COME INTO
FOCUS. THE RAIN WILL BE SPREAD OUT OVER SEVERAL ROUNDS, PRIMARILY
SPANNING SATURDAY AND SUNDAY, WITH THE HEAVIEST RAIN CURRENTLY
EXPECTED BEFORE/DURING SUNRISE ON SUNDAY. OVERALL AVERAGES ACROSS
MUCH OF THE AREA WILL PROBABLY END UP IN THE 1 TO 2 INCH RANGE, WITH
SOME MULTI-COUNTY STREAKS OF 2-3"+. THE GOOD NEWS IS THAT BECAUSE
WE'RE IN A DROUGHT, THE RIVERS HAVE PLENTY OF ROOM TO PUT THIS
WATER. SOME OF THE MIDSIZED RIVERS IN THE AREA LIKE SYCAMORE CREEK
(HOLT), BUCK CREEK (GRANDVILLE), AND THE LOOKING GLASS RIVER (EAGLE)
ARE THE MOST LIKELY TO SEE RISES CLOSE TO BANKFULL, BUT NO RIVER
FLOODING IS EXPECTED UNLESS THIS STORM SERIOUSLY OVERPERFORMS OUR
EXPECTATIONS. IT WOULD PROBABLY TAKE 4"+ OVER A FAIRLY LARGE AREA TO
BEGIN FLOODING THE MIDSIZED TRIBUTARIES MENTIONED ABOVE.
NEVERTHELESS, WITH WATER LEVELS CURRENTLY RUNNING LOWER THAN NORMAL
DUE TO THE DROUGHT, NOTABLE WITHIN-BANK RISES ARE EXPECTED ACROSS
MINOR FLOODING DEVELOP IN THE CLASSIC LOW SPOTS AND OTHER POOR
DRAINAGE AREAS. IT'S HARD TO PIN DOWN WHICH URBAN AREAS WOULD BE
MOST AT RISK OF THIS HAPPENING, BUT RECENT MODEL TRENDS SUGGEST THE
EASTERN EDGES OF OUR AREA ARE MOST AT-RISK, WHICH WOULD INCLUDE
LANSING AND JACKSON AREAS. ANYONE WITH PERSONAL PROPERTY NEAR THE
WATERS EDGE LEFTOVER FROM THE SUMMER SHOULD PREPARE FOR RISING
WATER.
WHILE RIVER FLOODING ISN'T A BIG CONCERN, IF SOME SLOW-MOVING HEAVY
RAIN BANDS PARK OVER SOME OF OUR URBAN AREAS WE COULD SEE SOME
LOCALIZED MINOR FLOODING DEVELOP IN THE CLASSIC LOW SPOTS AND OTHER
POOR DRAINAGE AREAS. IT'S HARD TO PIN DOWN WHICH URBAN AREAS WOULD
BE MOST AT RISK OF THIS HAPPENING, BUT RECENT MODEL TRENDS SUGGEST
THE EASTERN EDGES OF OUR AREA ARE MOST AT-RISK, WHICH WOULD INCLUDE
LANSING AND JACKSON AREAS.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...GALE WARNING FROM 8 AM THIS MORNING TO 11 PM EDT THIS EVENING
FOR LMZ844>849.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LMZ844>849.
DISCUSSION...CERU/RAH
AVIATION...RAH
MARINE...CERU
HYDROLOGY...AMD
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