277
FXUS63 KGRR 190905
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
405 AM EST FRI DEC 19 2025
KEY MESSAGES
- WINDY WITH A SNOWY LAKESHORE
- ROLLER COASTER TEMPERATURES THROUGH THE WEEKEND
- WARMER TEMPERATURES AHEAD
DISCUSSION
ISSUED AT 338 AM EST FRI DEC 19 2025
- WINDY WITH A SNOWY LAKESHORE
BOTTOM LINE UPFRONT: HAVE ISSUED A WINDY ADVISORY BASED ON THE
STRONG MID LEVEL FORCING DUE TO THE APPROACHING COLD FRONT AND THE
STRONG GRADIENT AND ADVECTING COLD TEMPERATURES BEHIND THE FRONT.
SNOW ACCUMULATIONS AMOUNTS, THOUGH DELAYED REMAIN SIMILAR WITH 1
TO 4 INCHES ALONG THE LAKESHORE THIS MORNING
STRONG COLD FRONT OUT AHEAD OF AN UPPER LEVEL LOW DIGGING INTO THE
MIDWEST WILL MOVE THROUGH THE REGION. A DEEP MID LEVEL TROUGH IS
CORRESPONDING WITH UPWARDS OF 50KTS AT 700MB. -16C AIR AT 850MB
DIGS ACROSS WESTERN MICHIGAN LATE THIS MORNING AND INTO THE
AFTERNOON. COUPLE THAT WITH THE WINDS MENTIONED, ALONG WITH
WIDESPREAD 40 J/KG OF CAPE AND MIXING DOWN THOSE WINDS TO THE
SURFACE IS LIKELY. 38 TO 42KTS HAVE ALREADY STARTED TO OCCUR AT A
FEW OBSERVATION SITES.
A WEAK RIDGE WILL TAMPER OFF THE NW FLOW AND EFFECTIVELY END THE
GUSTY WINDS AND ANY REMAINING LAKE EFFECT SNOWFALL THIS EVENING.
- ROLLER COASTER TEMPERATURES THROUGH THE WEEKEND
THAT RIDGE MENTIONED WILL BRING ANOTHER ROUND OF WARM AIR
ADVECTION INTO THE AREA SATURDAY. THE WHIPLASH OF TEMPERATURES
CONTINUES WITH 850MB TEMPS GO FROM -16C TODAY TO +4C TOMORROW.
SO HIGH'S TODAY WILL BE IN THE MID 20S, COMPARED TO THE UPPER 40S
TO LOW 50S YESTERDAY. SATURDAY THEN LOOKS TO BE BACK INTO THE MID
30S.
A WEAK CLIPPER SHOULD THEN SWING THROUGH EARLY SUNDAY, DROPPING
TEMPERATURES BACK INTO THE 20S. HOWEVER, THAT CLIPPER HAS VERY
LITTLE ASSOCIATED MOISTURE, SO NOT EXPECTING MUCH IN THE WAY OF
SNOWFALL ACCUMULATIONS.
TO PUT THESE SWINGS INTO PERSPECTIVE, HIGHS YESTERDAY WERE 14
DEGREES ABOVE NORMAL. TODAY IS EXPECTED TO BE AROUND 10 DEGREES
BELOW NORMAL. SATURDAY THEN 5 DEGREES ABOVE NORMAL. FINALLY,
SUNDAY IN BACK TO 10 DEGREES BELOW NORMAL.
- WARMER TEMPERATURES AHEAD
THE WEEK AHEAD IS TRENDING TO HAVE LESS TEMPERATURES SWINGS.
HOWEVER THE TREND WILL BE IN ONE DIRECTION AND THAT IS WARMER.
THE WEEK BEGINS WITH LOWS IN THE TEENS AND HIGHS BACK INTO THE
30S. THE TREND CONTINUES TO WARM WITH CHRISTMAS HIGHS POTENTIALLY
INTO THE 50S WITH LOWS ABOVE FREEZING. ZONAL FLOW THROUGH THE WEEK
WILL BRING A CHANCE FOR RAIN/SNOW MIX LATE MONDAY INTO TUESDAY.
THE COLDER AIR WITH THAT EVENT SHOULD TREND TOWARDS SNOW. HOWEVER,
ADVECTING WARM AIR COULD ALLOW FOR PRECIP TO END AS RAIN ON
TUESDAY.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1151 PM EST THU DEC 18 2025
WEST WINDS WILL GUST TO 30 KNOTS AT TIMES THROUGH FRIDAY
AFTERNOON. LAKE EFFECT SNOW SHOWERS BEGIN OVERNIGHT WITH AREAS OF
IFR PERSISTING INTO FRIDAY AFTERNOON BEFORE TAPERING OFF. MVFR
CONDITIONS PREVAIL THROUGH THE EVENING.
MARINE
ISSUED AT 338 AM EST FRI DEC 19 2025
STRONG WESTERLY FLOW WILL SHIFT TO NORTHWEST TODAY. THE GRADIENT
OVER THE LAKE SHOULD CONTINUE INTO THIS AFTERNOON. GIVEN THAT
TREND, HAVE EXTENDED THE GALE UNTIL 1 PM. WINDS WILL SLACKEN THIS
AFTERNOON THOUGH WIND GUSTS HAZARDOUS TO SMALL CRAFT SHOULD
CONTINUE THROUGH THE EVENING AND INTO AT LEAST SATURDAY.
GRR WATCHES/WARNINGS/ADVISORIES
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ037-
038-043-050-056-064-071-072.
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
MARINE...GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LMZ844>849.
DISCUSSION...CERU
AVIATION...OSTUNO
MARINE...CERU
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