369
FXUS63 KGRR 160613
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
213 AM EDT MON MAR 16 2026
KEY MESSAGES
- RAIN AND THUNDER TONIGHT WITH A LOW THREAT FOR SEVERE STORMS
- MUCH COLDER WITH LAKE EFFECT SNOW ON MONDAY INTO TUESDAY
UPDATE
ISSUED AT 159 AM EDT MON MAR 16 2026
ISSUED BY NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
ISSUED AT 857 PM EDT SUN MAR 15 2026
COLDER AIR HAS MAINTAINED ITSELF OVER THE NORTHERN CWA WITH SITES
REPORTING TEMPS AT OR JUST BELOW FREEZING. THIS HAS PREVENTED A
FULL CHANGEOVER TO LIQUID RAIN, INSTEAD FALLING MAINLY AS FREEZING
RAIN WITH SOME SNOW MIXING IN. AS SUCH, ICE ACCUMULATIONS UP TO
AROUND A TENTH OF AN INCH ARE LIKELY FROM CLARE TO MASON COUNTIES
THOUGH SOME AREAS, PARTICULARLY MASON, COULD BE CLOSER TO
0.15-0.2". EVENING UPDATE WAS TO BEGIN THE WINTER WEATHER
ADVISORIES FOR NEWAYGO, OCEANA, MASON, AND LAKE THIS EVENING TO
ACCOUNT FOR ICING BEFORE SNOW TOMORROW AS WELL AS ADDING OSCEOLA
AND CLARE FOR TONIGHT GIVEN THEIR ICE POTENTIAL. A SHORT FUSED
UPGRADE TO ADVISORY FOR MECOSTA COULD BE NEEDED TONIGHT IF OBS
BEGIN TO SHOW FREEZING RAIN MAKING INROADS THAT FAR SOUTHEAST.
DISCUSSION
ISSUED AT 303 PM EDT SUN MAR 15 2026
- RAIN AND THUNDER TONIGHT WITH A LOW THREAT FOR SEVERE STORMS
WE HAVE HOISTED A WINTER WEATHER ADVISORY FOR THE WESTERN TWO ROWS
OF COUNTIES AND EXTENDED AND EXPANDED THE WIND ADVISORY.
TEMPERATURES ACROSS LOWER MICHIGAN THIS AFTERNOON RANGE FROM 30
DEGREES AT CAD TO NEAR 70 AT THE MI-IND BORDER. DESPITE OVER 50
KNOTS OF DEEP LAYER SHEAR, THE SEVERE WEATHER THREAT IS LIMITED BY
A LACK OF INSTABILITY AS SEEN BY FORECAST AND OBSERVED SOUNDINGS.
A FIRST BATCH OF CONVECTION HAS WEAKENED AS IT MOVED INTO A MORE
STABLE ENVIRONMENT THIS AFTERNOON WITH DEW POINTS STILL IN THE 30S
DOWN TO I-94. THE DEW POINTS ACROSS THE SOUTHERN ZONES SHOULD
RECOVER TO THE LOWER 50S BASED ON UPSTREAM OBS, BUT THE THREAT FOR
SEVERE APPEARS TO BE LIMITED TO ISOLATED WIND GUSTS THIS EVENING
ACROSS THE FAR SOUTHERN/SOUTHEAST ZONES.
SFC LOW TRACKS THROUGH CENTRAL LOWER MICHIGAN WITH COLD ADVECTION
BEGINNING AFTER MIDNIGHT AND SYNOPTIC WINDS EXPECTED TO BEGIN OR
CONTINUE GUSTING TO 40 TO 50 MPH FOR ALL ZONES BY DAYBREAK.
- MUCH COLDER WITH LAKE EFFECT SNOW ON MONDAY INTO TUESDAY
STRONG CAA CONTINUES ALL DAY MONDAY AND TEMPERATURES WILL DROP
INTO THE TEENS BY EVENING. MODEL SOUNDINGS SHOW INVERSION HEIGHTS
AROUND 8 KFT AND STRONG NORTHWEST FLOW WITH SNOW SHOWERS
PENETRATING FAR INLAND. WITH TEMPERATURES WELL BELOW FREEZING,
BLOWING SNOW WILL REDUCE VISIBILITIES THROUGH TUESDAY MORNING.
THE SNOW SHOWERS WILL DIMINISH ON TUESDAY AS THE UPPER TROUGH AXIS
SHIFTS EAST SURFACE HIGH PRESSURE BUILDS IN.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 212 AM EDT MON MAR 16 2026
A COMPLEX WEATHER SCENARIO FOR AVIATION INTERESTS THE NEXT 24
HOURS AS A STRONG LOW PRESSURE SYSTEM WORKS NORTHEAST THROUGH THE
STATE. THE LOW AT 06Z IS LOCATED IN SOUTHWEST LOWER MICHIGAN NEAR
BENTON HARBOR (BEH). WINDS AT THE TAF SITES ARE ALL FROM AN
EASTERLY DIRECTION. AS THE LOW TRACKS TO THE NORTH THE REMAINDER
OF THE NIGHT WINDS WILL SHIFT TO THE SOUTHWEST AT MOST SITES AND
INCREASE IN SPEED. WINDS WILL INCREASE TO 15 TO 30 KNOTS BEFORE
DAYBREAK. WINDS AT MKG WILL BECOME NORTHWEST BY THE SAME TIME.
COLDER AIR WILL WRAP INTO STATE AS THE LOW MOVES NORTHEAST AND ANY
RAIN SHOWERS WILL SWITCH TO SNOW BY 12Z OR SO. WINDS MONDAY
MORNING AFTER 12Z WILL HAVE THE POTENTIAL TO REACH 30+ KNOTS AT
ALL SITES WITH MKG POSSIBLY REACHING 40 KNOTS. IT IS AFTER THE 16Z
TO 18Z TIME FRAME WHEN WINDS MARKEDLY INCREASE. GUSTS WILL LIKELY
HIT THE 35 TO 45 KNOT RANGE AT MOST SITES MONDAY AFTERNOON AND
EARLY EVENING.
SNOW AND BLOWING SNOW WILL DEVELOP IN THE 09Z TO 12Z TIME FRAME
AND BECOME PREVALENT AFTER 12Z, ESPECIALLY AT MKG, AZO AND GRR.
CEILINGS WILL BE IFR AT MANY SITES MONDAY MORNING FROM IMPROVING
INTO THE MVFR RANGE INTO MONDAY AFTERNOON. GIVEN THE WIND, SNOW
AND BLOWING SNOW AND LOW CEILINGS, POOR AVIATION CONDITIONS ARE
EXPECT DURING THE TAF PERIOD.
MARINE
ISSUED AT 303 PM EDT SUN MAR 15 2026
NO CHANGES TO THE GALE AND HEAVY FREEZING SPRAY WARNINGS. AFTER A
LINE OF SHOWERS AND THUNDERSTORMS GO THROUGH THIS EVENING THE WINDS
WILL GO NORTHWEST ON MONDAY WITH OCCASIONAL GUSTS TO 40 KNOTS.
GRR WATCHES/WARNINGS/ADVISORIES
MI...WINTER WEATHER ADVISORY UNTIL 8 AM EDT THIS MORNING FOR
MIZ037>040-043-044.
WIND ADVISORY UNTIL 11 PM EDT THIS EVENING FOR MIZ039-040-045-
046-051-052-058-059-064>067-071>074.
WINTER WEATHER ADVISORY FROM 8 AM THIS MORNING TO 11 AM EDT
TUESDAY FOR MIZ050-056-057-064-065-071-072.
MARINE...GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LMZ844>849.
HEAVY FREEZING SPRAY WARNING FROM 8 AM THIS MORNING TO NOON EDT
TUESDAY FOR LMZ844>849.
UPDATE...
DISCUSSION...OSTUNO
AVIATION...DUKE
MARINE...OSTUNO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page