606
FXUS63 KGRR 062025
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
325 PM EST SAT DEC 6 2025
KEY MESSAGES
- CLIPPER SYSTEM LIGHT SNOW TONIGHT INTO SUNDAY MORNING
- SOUTHWEST FLOW LAKE ENHANCED SNOW MONDAY NIGHT
- CLIPPER SYSTEM SNOW TUESDAY NIGHT INTO WEDNESDAY
- ADDITIONAL SNOW CHANCES THURSDAY INTO NEXT SATURDAY
DISCUSSION
ISSUED AT 325 PM EST SAT DEC 6 2025
- CLIPPER SYSTEM LIGHT SNOW TONIGHT INTO SUNDAY MORNING
A MID LEVEL SHORTWAVE IS WORKING OUT OF THE ROCKIES AND INTO THE
PLAINS THIS AFTERNOON WHICH HAS ALREADY ALLOWED FOR SURFACE LOW
PRESSURE TO FORM IN NEBRASKA. LIGHT SNOW IS BROKEN OUT AHEAD OF
THE LOW ACROSS SD/MN/IA. THE LOW WILL MOVE EASTWARD TONIGHT INTO
THE OHIO VALLEY, FILLING AS DOES. SNOW IS STILL EXPECTED TO MOVE
INTO SOUTHWEST LOWER MICHIGAN OVERNIGHT AND PERSIST INTO SUNDAY
MORNING. THIS LOOKS TO MAINLY BE A 100AM TO 100PM EVENT. LIQUID
EQUIVALENT AMOUNTS ARE NOT HIGH (0.05 TO 0.15). A WEAKENING
SYSTEM WILL MOVE INTO THE AREA WITH SMALLISH LIQUID EQUIVALENT, SO
SNOWFALL WILL BE ON THE LIGHT SIDE AS WELL. WE ARE EXPECTING AN
INCH OR TWO IN MOST LOCATIONS. CANNOT RULE OUT A TOTAL TOWARDS 3
INCHES IN A FEW SPOTS, BUT THIS DOES NOT LOOK TO BE THE NORM.
- SOUTHWEST FLOW LAKE ENHANCED SNOW MONDAY NIGHT
THE PREVAILING UPPER FLOW FOR MUCH OF THE NEXT 7 DAYS WILL BE SOME
VARIATION OF NORTHWEST WHICH LEADS TYPICALLY TO CLIPPER SYSTEMS
THIS TIME OF YEAR. THAT IS THE CASE WITH THIS TIME FRAME AS WELL,
WITH MULTIPLE CLIPPER SYSTEMS TO BRING ROUNDS OF LIGHT SNOW AND
OCCASIONALLY COLDER AIR. MONDAY NIGHT INTO TUESDAY MORNING THE
NEXT CLIPPER IN THE SERIES AFFECTS WEST CENTRAL LOWER MICHIGAN
WITH A SOUTHWEST FLOW LAKE ENHANCED EVENT WHICH WILL BRING
ACCUMULATING SNOW TO AREAS LIKE LUDINGTON, PENTWATER AND BALDWIN.
THE SURFACE LOW AND UPPER SHORTWAVE PASS OFF TO THE NORTH, SO
THAT IS WHERE THE MORE IMPACTFUL SNOW WILL FALL. THE
AFOREMENTIONED AREAS MAY SEE 1-3 OR 2-4 INCHES WITH THIS SHORT
DURATION EVENT. HIGHEST SNOW TOTALS IN OUR AREA OF RESPONSIBILITY
WILL LIKELY BE ACROSS MASON, OCEANA AND LAKE COUNTIES.
- CLIPPER SYSTEM SNOW TUESDAY NIGHT INTO WEDNESDAY
THE STRONGEST SYSTEM OF THE 7 DAY FORECAST LOOKS TO BE ANOTHER
CLIPPER TUESDAY NIGHT INTO WEDNESDAY. ALOFT A STRONG SHORTWAVE
PLOWS IN FROM THE WEST DURING THIS TIME FRAME. DOWN AT THE
SURFACE, A DEEP LOW FOR A CLIPPER WILL PASS RIGHT THROUGH THE
HEART OF THE STATE MOVING THROUGH CENTRAL LOWER MICHIGAN MOST
LIKELY. WEDNESDAY MORNING, THE LOW IS CENTERED SOMEWHERE NEAR MT
PLEASANT USING AN AGGREGATE OF THE OPERATIONAL MODELS WITH A DEPTH
AROUND 988MB. A FORMIDABLE LOW FOR SURE. THE HEAVIEST SWATH OF
PRECIPITATION USUALLY FALLS NEAR AND TO THE NORTH OF THE LOW TRACK
OF A CLIPPER AND THAT IS WHAT THE MODELS ARE INDICATING WITH THIS
SYSTEM AS WELL. QUITE A BIT OF TIME BEFORE WE DEAL WITH THIS
SYSTEM AND WE WILL BE WATCHING TRENDS CLOSELY. IF THE TRACK COMES
A LITTLE FURTHER SOUTH, MORE OF THE FORECAST AREA WILL GET INTO
THE HEAVIER PRECIPITATION. EVEN ON THE CURRENT TRACK THOUGH,
CENTRAL MICHIGAN IS IN LINE TO SEE SIZABLE ACCUMULATIONS OF SNOW
(POSSIBLY 4-7 INCHES). AGAIN, THIS COULD INCLUDE MORE OF SOUTHWEST
LOWER MICHIGAN IF THE TRACK TRENDS SOUTHWARD. THIS IS A BIT OF A
WARMER SYSTEM AS THE STRONGER LOW PULLS IN WARM AIR FROM THE
SOUTH, THEREFORE THE I-96 CORRIDOR TO THE SOUTH WILL LIKELY SEE A
RAIN/SNOW MIX WITH THIS EVENT. AGAIN, TRENDS IN THE MODELS WILL BE
EVERYTHING WITH REGARD TO TYPE AND AMOUNTS OF PRECIPITATION.
- ADDITIONAL SNOW CHANCES THURSDAY INTO NEXT SATURDAY
ANOTHER WEAK CLIPPER SYSTEM PASSES WELL OFF TO OUR SOUTH ON
THURSDAY WITH CHANCES THAT MOST OF THE PRECIPITATION STAYS IN
THAT DIRECTION AS WELL. A PERIOD OF LAKE EFFECT SNOW THEN LOOKS TO
SET UP FROM FRIDAY INTO SATURDAY AS PROGRESSIVELY COLDER AIR
INFILTRATES THE AREA ON NORTHWEST WINDS. A SIGNIFICANT BATCH OF
COLD AIR WORKS INTO THE PLAINS DURING THIS PERIOD WHICH WILL PUT
SOUTHWEST LOWER MICHIGAN INTO -10C TO -20C AIR AT 850MB. THIS WILL
PUT DELTA T'S OVER THE LAKE IN THE 17 TO 27 C RANGE WHICH IS HIGH
TO EXTREME. LAKE EFFECT WILL CONTINUE WITH LIKELY A SMALL FLAKE
SIZE. AS WE GET INTO THIS TEMPERATURE SETUP ROAD CONDITIONS TEND
TO DETERIORATE AS HIGHS ARE HELD AT BEST IN THE 20S. THE SURFACE
PATTERN FRIDAY INTO SATURDAY IS INDICATIVE OF A VERY COLD AIR
LAKE EFFECT SETUP AS WE SEE LEE SIDE TROUGHING NEAR THE GREAT
LAKES DUE TO THERMAL AFFECTS. PLENTY OF LIGHT SNOW AND LIGHT
ACCUMULATIONS WITH THE POTENTIAL FOR HIGHER IMPACT POOR ROAD
CONDITIONS.
BOTTOM LINE, THE FORECAST OVER THE NEXT 7 DAYS VERY MUCH SPEAKS
WINTER! MEANING, THERE ARE MULTIPLE CHANCES FOR ACCUMULATING SNOW
AND A COUPLE SHOTS OF COLDER AIR.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1151 AM EST SAT DEC 6 2025
SATELLITE AND OBSERVATIONAL TRENDS SUGGEST CEILINGS WILL BOUNCE
AROUND 3KFT OVER THE NEXT FEW HOURS FOR MKG AND GRR BEFORE THOSE
TERMINALS AND LAN CLIMB TO VFR FOR A BRIEF TIME THIS EVENING.
WIDESPREAD SNOW MOVES IN FROM THE WEST TONIGHT AS A LOW PRESSURE
SYSTEM TRACKS SOUTH OF THE AREA. CONDITIONS WILL DETERIORATE TO
MVFR THEN IFR AT ALL TERMINALS AFTER 06Z. THERE IS A 10% CHANCE
OF LIFR CONDITIONS, LIKELY DEPENDENT ON WHETHER SOME LAKE
ENHANCEMENT CAN ADD TO SNOWFALL RATES. SNOW WINDS DOWN WITH
CONDITIONS IMPROVING TO MVFR AT MKG, GRR, AND LAN AFTER 15-17Z
WITH THE OTHER TERMINALS REMAINING IFR THROUGH THE END OF THE TAF
PERIOD. WEST TO NORTHWEST WINDS TO 10 KNOTS TODAY WILL BECOME
LIGHT AND VARIABLE TONIGHT INTO SUNDAY MORNING AS THE LOW PASSES
ACROSS NORTHERN INDIANA/OHIO.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LMZ844>849.
DISCUSSION...DUKE
AVIATION...THOMAS
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