015
FXUS63 KGRR 182000
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
300 PM EST THU DEC 18 2025
KEY MESSAGES
- RAIN CHANGING TO SNOW SHOWERS TONIGHT, WINDY
- UP/DOWN TEMPS THROUGH WEEKEND, THEN WARMER
DISCUSSION
ISSUED AT 300 PM EST THU DEC 18 2025
- RAIN CHANGING TO SNOW SHOWERS TONIGHT, WINDY
BASED ON UPDATED SNOW ACCUMULATIONS AND EXPECTED WIND, WE INCLUDED
ALL OF THE LAKE SHORE COUNTIES PLUS KALAMAZOO COUNTY IN THE WINTER
WEATHER ADVISORY.
REGIONAL RADAR SHOWS A BAND OF RAIN INCLUDING A NARROW COLD
FRONTAL RAIN BAND MOVING ACROSS EASTERN WISCONSIN AND ILLINOIS.
THIS RAIN WILL MOVE OVER THE CWA THIS EVENING JUST AHEAD OF THE
COLD FRONT. H8 TEMPS NEAR +8C WILL QUICKLY FALL TO -14C BY 06Z. WE
EXPECT LAKE EFFECT SNOW TO DEVELOP AROUND 03Z AND CONTINUE INTO
FRIDAY MORNING. AS BOUNDARY LAYER WINDS TRANSITION FROM WEST TO
NORTHWEST, SNOW WILL IMPACT ALL OF THE LAKE SHORE. GUSTY WINDS
WILL CONTINUE TONIGHT INFO FRIDAY MORNING AS HIGH PRESSURE RUSHES
IN BEHIND THE FRONT. 3HR MSL PRESSURE CHANGES INCREASE FROM
2-3MB/3 HR TO 5-6MB/3HR BY 15Z FRIDAY. STRONGEST WINDS WINDS WILL
BE ALONG THE LAKE SHORE AND GUST TO 40 MPH. TRAVEL IMPACTS ARE
EXPECTED AS THE SNOW AND WIND COMBINE TO PRODUCE BLOWING/DRIFTING.
ACCUMS ALONG THE LAKE SHORE WILL RANGE FROM 1-3 INCHES NORTH OF
MUSKEGON TO 2-4 SOUTH OF THERE. ELSEWHERE, ACCUMULATIONS AROUND A
HALF INCH ARE POSSIBLE.
THE CORE OF THE COLD AIR MOVES OUT QUICKLY AFTER 18Z FRIDAY AND
THE SNOW WILL END.
- UP/DOWN TEMPS THROUGH WEEKEND, THEN WARMER
HIGHS FRIDAY WILL BE IN THE MID 20S. BY SATURDAY, SOUTHWEST WINDS
AHEAD OF THE NEXT SHORT WAVE WILL PUSH TEMPERATURES INTO THE MID
30S. LIGHT SNOW IS POSSIBLE WITH THE SHORT WAVE NORTH OF I-96 BUT
LITTLE IN THE WAY OF ACCUMULATIONS ARE EXPECTED. BEHIND THE SHORT
WAVE SUNDAY, TEMPERATURES WILL BE IN THE LOWER 20S.
SUNDAY LOOKS DRY WITH HIGH PRESSURE IN CONTROL. A BUILDING HIGH
OVER THE CENTRAL US WILL SEND HEIGHTS AND TEMPERATURES UPWARD NEXT
WEEK FROM THE 30S MONDAY TO THE 40S TUESDAY THROUGH CHRISTMAS.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1233 PM EST THU DEC 18 2025
THE INITIAL BAND OF RAIN IS BRINGING PREDOMINANTLY MVFR CONDITIONS
TO THE TERMINALS AT PRESENT. A NARROW BAND OF HEAVIER RAIN THEN
MOVES THROUGH THE TERMINALS LATER THIS AFTERNOON INTO THIS EVENING
ASSOCIATED WITH COLD FRONTAL PASSAGE. UPSTREAM OBSERVATIONS
SUGGEST WIDESPREAD IFR CIGS, AND OBS WARRANTING A TEMPO FOR
BORDERLINE LIFR CONDITIONS AT ALL TERMINALS. A BRIEF INCREASE IN
WINDS AND SUDDEN SHIFT FROM SOUTH TO WEST IS LIKELY AS THE FRONT
CROSSES THE TERMINALS. GUSTS TO 35 KNOTS AS WELL AS LLWS CONTINUE
THROUGH THE AFTERNOON. TONIGHT, AFTER THE FRONT CLEARS, LAKE
EFFECT SNOW SHOWERS DEVELOP CONTINUING THROUGH FRIDAY MORNING.
AROUND 12Z WINDS BECOME MORE NORTHWESTERLY CONCENTRATING SNOW
SHOWERS TO MAINLY THE LAKESHORE (INC. MKG) AND AZO/BTL. POST
FRONTAL CIGS WILL BE MVFR AREAWIDE WITH MVFR AND LOWER VISBYS IN
LAKE EFFECT SNOW SHOWERS.
MARINE
ISSUED AT 300 PM EST THU DEC 18 2025
A GALE WARNING REMAINS IN EFFECT UNTIL 7 AM, AT WHICH TIME A SMALL
CRAFT ADVISORY WILL BE NEEDED. IT'S POSSIBLE THAT THE GALE WARNING
WILL BE EXTENDED A FEW HOURS FRIDAY MORNING. A TIGHT PRESSURE
GRADIENT IS IN PLACE AS DEEP LOW PRESSURE MOVES THROUGH THE GREAT
LAKES WHICH IS PRODUCING THE STRONG WINDS. WIND AND WAVES WILL BE
HAZARDOUS TO SMALL CRAFT THROUGH THE WEEKEND.
GRR WATCHES/WARNINGS/ADVISORIES
MI...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
FRIDAY FOR MIZ037-038-043-050-056-064-071-072.
MARINE...GALE WARNING UNTIL 7 AM EST FRIDAY FOR LMZ844>849.
DISCUSSION...04
AVIATION...THOMAS
MARINE...04
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page