932
FXUS63 KGRR 291726
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1226 PM EST WED JAN 29 2025
KEY MESSAGES
- CHANCE OF LIGHT SNOW THIS MORNING
- MIXED PRECIPITATION THURSDAY NIGHT/FRIDAY
- CHANCE OF RAIN/SNOW SATURDAY NIGHT/SUNDAY NIGHT
UPDATE
ISSUED AT 1056 AM EST WED JAN 29 2025
NO NOTICEABLE CHANGES NEEDED TO THE FORECAST THIS MORNING. THERE
ARE A FEW LIGHT SNOW SHOWERS ACROSS THE NORTHERN SECTIONS OF THE
FORECAST AREA. OBSERVATIONS UNDER THE SNOW SHOWERS HAVE GENERALLY
STAYED ABOVE 3 MILES, WHICH MEANS THAT THESE ARE NOT VERY STRONG
AND MOST LIKELY NOT ACCUMULATING. THESE SNOW SHOWERS ARE THE
RESULT OF THE UPPER JET/SHEAR ZONE OVER THAT AREA, AND SHORT WAVE
ACTIVITY MOVING THROUGH. THE SNOW SHOWERS WILL DISSIPATE THIS
AFTERNOON AS THE SHEAR ZONE AND SHORT WAVE MOVE OUT OF THE AREA.
JUST A LOT OF CLOUD COVER ELSEWHERE, WITH MORE BREAKS IN THE
CLOUDS BEING FOUND ACROSS THE SOUTH. WE WILL TEND TO SEE AN
IMPROVING TREND THIS AFTERNOON AS THE UPPER FLOW BECOMES MORE
ANTI-CYCLONIC, WITH BETTER CLEARING AFTER SUNSET.
TEMPERATURES MAXED OUT EARLIER THIS MORNING IN THE UPPER 30S TO
LOWER 40S, AS THE COLD FRONT HAS EXITED THE AREA TO THE SOUTH AND
COOLER AIR IS ADVECTING IN.
DISCUSSION
ISSUED AT 314 AM EST WED JAN 29 2025
- CHANCE OF LIGHT SNOW THIS MORNING
LATEST WATER VAPOR IMAGERY SHOWS A SHORT WAVE TROUGH OVER THE UP
AND NORTHERN LOWER WHICH IS WELL DEPICTED IN THE MODELS. THERE'S
SOME LIGHT PRECIPITATION ASSOCIATED WITH IT AS SEEN ON RADAR OVER
NORTHERN LOWER AND NORTHERN WISCONSIN. THAT LIGHT SNOW (AND SOME
RAIN NEAR THE SHORE) WILL ROTATE THROUGH THE CWA THIS MORNING AND
MAY BRING A DUSTING TO HALF INCH OVER THE NORTHWEST CWA AND NOT
MUCH MORE ELSEWHERE. THE PRECIPITATION SHOULD BE EAST OF THE CWA
BY THIS AFTERNOON. A SLUG OF COLDER AIR ACCOMPANIES THE
PRECIPITATION AND WE'LL SEE HIGHS IN THE MID 20S NORTH TO MID 30S
SOUTH TODAY.
- MIXED PRECIPITATION THURSDAY NIGHT/FRIDAY
WATER VAPOR IMAGERY ALSO SHOWS A LARGE UPPER LOW OVER THE
SOUTHWEST US AND THIS WILL BE OUR NEXT WXMAKER IS IT MOVES EAST.
MODELS HAVE BEEN SHOWING A SOUTHERN STREAM SYSTEM DEVELOPING OVER
NORTHERN TX FOR SEVERAL DAYS AND CONFIDENCE IS PRETTY HIGH THAT
WE'LL SEE LOW PRESSURE MAKE A RUN AT THE SOUTHERN GREAT LAKES LATE
TOMORROW AND FRIDAY. MODEL TRENDS HAVE BEEN TO PUSH THE
PRECIPITATION SHIELD A BIT NORTHWARD TO NEAR US-10. GIVEN THE
SOUTHERN ORIGIN OF THE SYSTEM, WE'LL SEE A PUSH OF WARMER AIR
AHEAD OF IT AND THE PRECIPITATION THAT BEGINS THURSDAY NIGHT WILL
BE RAIN. LATEST GFS SOUNDINGS SHOW A PRONOUNCED WARMING IN THE
LOWEST 150MB INDICATIVE OF POTENTIAL FREEZING PRECIPITATION.
THE FREEZING THREAT HINGES ON THE TIMING OF A NORTHERN STREAM
CLIPPER THAT WILL BE MAKING A RUN AT THE STRAITS THURSDAY NIGHT
AND PUSH A COLD FRONT SOUTHWARD INTO THE CWA OVERNIGHT THURSDAY
AND FRIDAY MORNING. IF THE COLDER AIR NEAR THE SURFACE ARRIVES
CONCURRENTLY WITH THE SLUG OF MOISTURE FROM THE SOUTH, THEN
FREEZING RAIN REMAINS A POSSIBILITY NORTH OF M-46. IT'S NOT A
CERTAINTY YET, BUT BEARS WATCHING.
EVENTUALLY, THE COLDER AIR WILL SETTLE IN AND WE'LL SEE THE RAIN
MIX WITH SNOW. THUS, TRAVEL COULD BE IMPACTED FRIDAY MORNING
ACROSS THE CENTRAL CWA.
- CHANCE OF RAIN/SNOW SATURDAY NIGHT/SUNDAY NIGHT
A NORTHERN STREAM SHORT WAVE IS PROGD TO MOVE ACROSS THE CWA
SATURDAY NIGHT AND SUNDAY MORNING PRODUCING SOME LIGHT SNOW. THIS
LOW WILL MOVE ACROSS THE NORTHERN CWA AND THE BULK OF THE
PRECIPITATION WITH IT WILL BE NORTH OF THE CWA.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1226 PM EST WED JAN 29 2025
LITTLE TO NO IMPACT EXPECTED AT ALL OF THE TERMINALS OVER THE NEXT
24 HOURS. CEILINGS HAVE GONE VFR AT OF OUR TERMINALS, WITH KAZO
AND KBTL EITHER HAVING SCATTERED OUT, OR WILL DO SO VERY SOON. THE
CLOUDS WILL THEN DIMINISH THROUGH EARLY THIS EVENING FROM SOUTH TO
NORTH. ONLY SOME HIGH CLOUDS WILL THEN REMAIN OVERNIGHT AND
THURSDAY.
WIND GUSTS FROM THE NW WILL CONTINUE UNTIL ALMOST SUNSET BEFORE
DIMINISHING. LIGHT WINDS WILL SWITCH OVERNIGHT TO BECOME FROM THE
SOUTH. WINDS WILL THEN BECOME GUSTY ONCE AGAIN TOWARD 17Z THURSDAY
TO AROUND 20-24 KNOTS AS BETTER DIURNAL MIXING TAKES PLACE.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR LMZ844>849.
UPDATE...NJJ
DISCUSSION...04
AVIATION...NJJ
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