301
FXUS63 KGRR 022044
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
344 PM EST SUN FEB 2 2025
KEY MESSAGES
- AREAS OF FOG TONIGHT AND MONDAY MORNING
- LIGHT MIX NEAR U.S. 10 MONDAY
- WINTRY MIX WEDNESDAY NIGHT; BREEZY THURSDAY
DISCUSSION
ISSUED AT 344 PM EST SUN FEB 2 2025
- AREAS OF FOG TONIGHT AND MONDAY MORNING
A FRESH 1-2" WET SNOW COVER PUT DOWN BY THIS MORNING'S QUICK-
HITTING SYSTEM IS IN PLACE AND TEMPS/DEW POINTS WILL CONTINUE TO
SLOWLY RISE TONIGHT. WITH LIGHT WINDS EXPECTED THE RESULT WILL BE
FOR AREAS TO FOG TO FORM, SOME OF WHICH COULD BECOME DENSE.
VISIBILITIES BELOW ONE HALF MILE ARE ALREADY OCCURRING NEAR THE
MI/IN BORDER. WE MAY NEED TO CONSIDER A DENSE FOG ADVISORY FOR
THE MONDAY MORNING COMMUTE TIME DEPENDING ON TRENDS LATER TONIGHT.
SOME LOCATIONS NORTH OF ABOUT M-46 MAY STAY JUST COLD ENOUGH FOR
FREEZING FOG/BLACK ICE TO EVEN OCCUR TONIGHT.
- LIGHT MIX NEAR U.S. 10 MONDAY
ELONGATED BUT NARROW BAND OF ACCUMULATING, FGEN-FORCED SNOW ALONG
A TIGHT MID LEVEL BAROCLINIC ZONE OVER THE NORTH CENTRAL U.S.
LOOKS TO STAY JUST NORTH OF THE GRR CWFA AREA MONDAY. HOWEVER ON
THE SOUTHERN FLANK OF THAT BAND THERE MAY BE A BIT OF LIGHT MIXED
PRECIPITATION NEAR THE U.S. 10 CORRIDOR. FORECAST SOUNDINGS
INDICATE THAT SNOW AND RAIN (OR A MIX THEREOF) ARE EQUALLY
POSSIBLE IN THIS AREA AND THERE IS ALSO A LOW RISK FOR A PERIOD OF
LIGHT FREEZING RAIN IF/WHERE TEMPS STAY COLD ENOUGH SUCH AS
AROUND CLARE/HARRISON.
- WINTRY MIX WEDNESDAY NIGHT; BREEZY THURSDAY
SPECIFIC DETAILS OF THE MIDWEEK SYSTEM ARE STILL NOT VERY CLEAR.
THIS SYSTEM IS AIDED BY A COUPLED JET STRUCTURE ALOFT, WITH A 150
KT PACIFIC JET STRETCHING EAST FROM CA PROVIDING LFQ LIFT WHILE
ANOTHER 120KT JET SITUATED FROM NORTH OF LAKE SUPERIOR TO NEW
ENGLAND PROVIDES COINCIDENT RRQ LIFT.
MODELS/ENSEMBLES HAVE VARYING SOLUTIONS OF HOW THIS ALL PLAYS
OUT, WITH ONE CAMP (MAINLY THE GFS/GEFS) KEEPING THE HEAVIER QPF
DOWN THROUGH THE OHIO VALLEY AND A COLDER SOLUTION OVER MI WITH
MORE OF A LIGHT SNOW THREAT (AND SOME RISK OF FREEZING RAIN IN THE
SOUTH). ANOTHER CAMP (MAINLY THE ECWMF/ECE) HAS A MORE NRN SFC
LOW TRACK WHICH PULLS THE BETTER WAA QPF FARTHER NORTH WITH A
STRONGER RISK OF FREEZING RAIN AS THE PREDOMINANT P-TYPE.
OBVIOUSLY THE EC SOLUTION WOULD BE MORE IMPACTFUL ESPECIALLY IF
THE PRECIP IS CONVECTIVE AS SUGGESTED BY ITS MUCAPE PROGS AND IF
IT IS MOSTLY FREEZING RAIN. THE PRIMARY TIME OF CONCERN LOOKS TO
BE LATE WED AFTERNOON AND WED EVENING WHEN THE LOW LEVEL JET WILL
BE AIMED AT THE AREA. MID LEVEL DRY SLOT THEN PUNCHES IN QUICKLY
LATE WED NIGHT/EARLY THURSDAY BRINGING AN ABRUPT DIMINISHING TREND
TO THE PRECIP. THE EC SOLUTION ALSO SUPPORTS SOME FAIRLY STRONG
WIND GUSTS IN THE DRY SLOT ON THURSDAY, POSSIBLY EXCEEDING 40/45
MPH PER ENSEMBLE MEANS.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1219 PM EST SUN FEB 2 2025
IFR CONDITIONS ARE SETTLING IN ACROSS THE AREA WITH PERIODS OF
LIFR (AND POSSIBLY LOWER) CONDITIONS THIS AFTERNOON INTO THIS
EVENING. THIS MIX OF IFR AND LIFR CIGS AND AREAS OF MVFR TO IFR
FOG WILL PERSIST THROUGH THE TAF WINDOW AS LIGHT LOW-LEVEL WINDS
KEEP MOISTURE IN PLACE. WINDS WILL BE 3-8 KNOTS FROM THE SW TODAY
BECOMING LIGHT AND VARIABLE OVERNIGHT. ONGOING FREEZING DRIZZLE AT
GRR MAY CONTINUE FOR THE NEXT HOUR OR TWO, OTHERWISE CONFIDENCE IN
ICING AT ALL OTHER SITES IS TOO LOW FOR TAF INCLUSION.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LMZ847>849.
DISCUSSION...MEADE
AVIATION...THOMAS
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