164
FXUS63 KGRR 151118
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
718 AM EDT SUN MAR 15 2026
KEY MESSAGES
- WINDY, WARMER, SHOWERS AND CHANCE OF THUNDERSTORM TODAY
- LAKE EFFECT SNOW MONDAY INTO TUESDAY
- QUICK ROUND OF SNOW WEDNESDAY
- DRIER AND WARMING UP INTO THE WEEKEND
DISCUSSION
ISSUED AT 412 AM EDT SUN MAR 15 2026
- WINDY, WARMER, SHOWERS AND CHANCE OF THUNDERSTORM TODAY
FIRST, WINTER WEATHER ADVISORY THIS MORNING CONTINUES ALONG AND
NORTH OF M-20 BUT SHOULD MOSTLY BE DONE WITH MEANINGFUL
PRECIPITATION BY LATE MORNING. SLOWER HIGHWAY SPEEDS DUE TO SNOW
WERE OBSERVED AT 3 AM ON US-131 NORTH OF CEDAR SPRINGS AND
US-127 NORTH OF ITHACA. A LIGHT AMOUNT OF SLEET OR FREEZING RAIN
COULD MIX IN PRIOR TO PRECIPITATION DWINDLING. WILL OPT TO LET
THIS WINTER WEATHER ADVISORY END BEFORE ISSUING THE NEXT ONE FOR
LAKE EFFECT SNOW ON MONDAY.
EXPANDED WIND ADVISORY IN SOUTHERN MICHIGAN TO INCLUDE ALLEGAN AND
BARRY COUNTIES. CONTEMPLATED EXPANDING NORTHWARD TO INCLUDE
MUSKEGON THROUGH GRATIOT FOR LATER IN THE AFTERNOON INTO EVENING
AS HREF DOES INDICATE SOME POTENTIAL FOR A PERIOD OF GUSTS OVER
45 MPH THERE, CONVECTIVE OR NOT, BUT CONFIDENCE IS LOWER NORTH OF
THE EXISTING ADVISORY.
STRONG LOW-LEVEL WIND FIELD WILL BE IN PLACE TODAY AHEAD OF A
STRENGTHENING LOW PRESSURE STORM SYSTEM. EXPECTING TEMPERATURES TO
SURGE INTO THE 50S AND 60S THIS AFTERNOON WITH A WARM FRONT
ADVANCING NORTHWARD INTO CENTRAL MICHIGAN. LOW LEVELS ARE EXPECTED
TO BE FAIRLY WELL MIXED IN SOUTHERN MICHIGAN ALTHOUGH CLOUD COVER
COULD LIMIT SURFACE GUST POTENTIAL SLIGHTLY. SOME SHOWERS AHEAD
OF THE COLD FRONT COULD ASSIST IN MIXING DOWN STRONG WINDS VIA
EVAPORATIVE COOLING. 40 TO 45 KNOT WINDS WILL BE LESS THAN 1000
FEET ABOVE THE GROUND, MAKING THE WIND ADVISORY AN EASY CALL. 50
TO 55 KNOT WINDS WILL BE PRESENT JUST ABOVE 1000 FEET FOR A TIME
THIS EVENING, SO SOME 60 MPH GUSTS COULD OCCUR, WHETHER ASSOCIATED
WITH A THUNDERSTORM OR NOT, IN THE VICINITY OF THE COLD FRONT.
- LAKE EFFECT SNOW MONDAY INTO TUESDAY
LATE SUNDAY NIGHT, STILL A CHANCE FOR MASON COUNTY AND PARTS OF
OCEANA, LAKE, AND OSCEOLA COUNTIES TO SNEAK INTO BRIEFLY MODERATE
FREEZING RAIN RATES JUST TO THE NORTH OF THE SURFACE LOW.
CONFIDENCE IS NOT VERY HIGH AND THE HREF SUITE HAS BEEN KEEPING
THE FREEZING RAIN ZONE FARTHER NORTH THAN THE GFS AND ECMWF. THIS
WILL HAVE TO BE WATCHED CLOSELY.
MONDAY INTO MONDAY NIGHT, TEMPERATURES FALLING DEEP INTO THE 20S
AND THEN TEENS AT NIGHT ALONG WITH WINDS GUSTING UP TO 45 MPH WILL
MAKE ROADS HAZARDOUS, REALLY ACROSS THE ENTIRE AREA. MODERATE SNOW
SHOWERS AND BLOWING SNOW WILL RESULT IN VARIABLE AND AT TIMES POOR
VISIBILITY. THE 2 TO 4 INCH TOTALS WILL BE MORE FAVORED IN THE
NORTHWEST-WIND LAKE EFFECT ZONES, GENERALLY NEAR AND WEST OF
US-131, AND LIGHTER ACCUMULATIONS WILL BE TO THE EAST.
- QUICK ROUND OF SNOW WEDNESDAY
OVERALL DECENT AGREEMENT WITHIN THE ENSEMBLES FOR A QUICK BURST OF
SNOW LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. TEMPERATURES ARE
EXPECTED TO BE IN THE TEENS, SO SNOW WILL LIKELY STICK AND CREATE
SLICK CONDITIONS FOR THE WEDNESDAY MORNING COMMUTE. OVERALL AMOUNTS
LOOK LIGHT WITH THE PROBABILITY OF 1 INCH OR MORE IN THE 20 TO 40
PERCENT RANGE WITH THE HIGHEST PROBABILITIES ALONG THE LAKESHORE.
- DRIER AND WARMING UP INTO THE WEEKEND
THE TROUGH THAT MOVES THROUGH WEDNESDAY WILL STALL OUT OVER THE
EASTERN CONUS WITH NORTHWEST FLOW REMAINING OVERHEAD. THERE IS A
SLIGHT SIGNAL FOR A COUPLE SHORTWAVES TO MOVE THROUGH THE NORTHWEST
FLOW, BUT MOISTURE IS QUESTIONABLE. OVERALL PROBABILITIES ARE LOW (20
PERCENT OR LESS) FOR MEASURABLE PRECIPITATION IN THE EXTENDED
FORECAST. HEADING INTO THE WEEKEND THERE ARE DEVIATING SOLUTIONS IN
THE OVERALL PATTERN IN THE CLUSTER ANALYSIS, HOWEVER 47 PERCENT OF
ENSEMBLE MEMBERS OF THE LREF FOCUS IN INCREASING PRESSURE HEIGHTS
FOR SATURDAY. WITH US NO EXPECTED TO SEE ANY DEEP TROUGHING OVERHEAD
AND THE POTENTIAL FOR INCREASING PRESSURE HEIGHTS, FORECAST
TEMPERATURES WARM INTO THE 40S AND 50S INTO NEXT WEEKEND.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 718 AM EDT SUN MAR 15 2026
LOW MVFR TO IFR IS GOING TO BE MOST PREVALENT TODAY AROUND LDM,
RQB, AND MOP. FOR MKG, GRR, AND LAN, LIKELY VFR UNTIL RAIN
SHOWERS DEVELOP DURING THE AFTERNOON/EVENING. GUSTY WINDS AND LLWS
WILL BE A PREVALENT CHALLENGE TODAY. RAIN SHOWERS LIKELY THIS
EVENING WITH A CHANCE OF A THUNDERSTORM. THESE COULD TEMPORARILY
BOOST WIND GUSTS OR FLUCTUATE THE AMOUNT OF LLWS EITHER WAY.
MARINE
ISSUED AT 412 AM EDT SUN MAR 15 2026
EAST GALES ARE POSSIBLE THIS MORNING, THEN SOUTH GALES ARE
POSSIBLE LATER THIS AFTERNOON INTO TONIGHT. A THUNDERSTORM IS
POSSIBLE THIS AFTERNOON INTO EVENING. NORTHWEST GALES ARE LIKELY
MONDAY MORNING THROUGH MONDAY NIGHT. HEAVY FREEZING SPRAY EXPECTED
MONDAY INTO TUESDAY MORNING.
HYDROLOGY
ISSUED AT 245 PM EDT SAT MAR 14 2026
RIVERS REMAIN HIGH AFTER SEVERAL RECENT ROUNDS OF HEAVY RAIN. WHILE
THE UPCOMING SUNDAY/MONDAY STORM LOOKS TO KEEP ITS HEAVIEST RAIN
NORTH OF OUR BIG WATERSHEDS, WE ARE STILL EXPECTING AROUND 1.5
INCHES OF RAIN NORTH OF I-96, INCLUDING ACROSS MUCH OF THE MUSKEGON
RIVER WATERSHED.
CURRENT RIVER MODELING SUGGESTS THIS MAY BE ENOUGH TO GENERATE
SOME MINOR FLOOD STAGE ON THE LOWER PORTIONS (BELOW CROTON DAM) OF
THE MUSKEGON RIVER IN THE MIDWEEK TIMEFRAME. MEANWHILE, FURTHER
SOUTH, THE LOWER GRAND RIVER IS ALREADY NEAR BANKFULL, AND JUST
BEGINNING TO DROP AFTER RECENT HIGH WATER. AN EXPECTED ONE-HALF
INCH OF RAIN COMING UP WILL PROLONG THIS HIGH WATER, BUT IS
CURRENTLY NOT EXPECTED TO CAUSE ANY NEW FLOODING. NEVERTHELESS,
SURPRISES HAPPEN, AND IF THE HEAVIER AXIS OF RAIN PIVOTS SOUTH
TOWARD THE KENT COUNTY AREA WE COULD GENERATE ADDITIONAL GENERAL
FLOODING AS WELL AS EVENTUAL RIVER FLOODING.
GRR WATCHES/WARNINGS/ADVISORIES
MI...WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
MIZ037>040-043>046.
WIND ADVISORY FROM 11 AM THIS MORNING TO MIDNIGHT EDT TONIGHT
FOR MIZ059-064>067-071>074.
MARINE...GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LMZ844>849.
HEAVY FREEZING SPRAY WARNING FROM 8 AM MONDAY TO NOON EDT
TUESDAY FOR LMZ844>849.
DISCUSSION...CAS/RAH
AVIATION...CAS
MARINE...CAS
HYDROLOGY...AMD
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