120
FXUS63 KGRR 162001
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
301 PM EST MON DEC 16 2024
KEY MESSAGES
- SNOW SHOWERS POSSIBLE LATER TUESDAY NIGHT/WEDNESDAY MORNING
- MINOR SNOW ACCUMULATIONS LATER THURSDAY INTO FRIDAY
- COLD WEEKEND
DISCUSSION
ISSUED AT 152 PM EST MON DEC 16 2024
- SNOW SHOWERS POSSIBLE LATER TUESDAY NIGHT/WEDNESDAY MORNING
A WEAK WAVE OF LOW PRESSURE TRACKS UP THE OH VALLEY DURING THIS
TIMEFRAME. COLDER AIR WILL BE FILTERING IN FROM THE NORTHEAST HERE
IN MI SO WE ARE EXPECTING ANY OF THE PRECIPITATION THAT FALLS FROM
THIS SYSTEM TO BE MAINLY IN THE FORM OF SNOW. THIS SYSTEM IS SHOWN
TO BE FAIRLY DISORGANIZED AS IT TRACKS INTO THE AREA BUT IT MAY
INCREASE IN STRENGTH AS IT MOVES AWAY. THE DGZ DOES MOISTEN UP AND
THERE IS SOME LIFT IN THAT ZONE SO WE WILL NEED TO MONITOR IT
CLOSELY. THE WEDNESDAY MORNING COMMUTE LOOKS TO BE ABOUT WHEN THE
BEST CHANCE FOR SNOW SHOWERS WILL BE SO, A RISK FOR SOME SLICK
SPOTS ON THE ROADWAYS EXISTS. ENSEMBLE SNOW AMOUNTS HAVE BEEN
HOLDING FAIRLY STEADY IN FAVORING MOST AREAS TO SEE LESS THAN AN
INCH FROM THIS RELATIVELY WEAK SYSTEM.
- MINOR SNOW ACCUMULATIONS LATER THURSDAY INTO FRIDAY
THIS NEXT CLIPPER SYSTEM WILL BE DIGGING INTO THE REGION LATER
THURSDAY AND INTO THURSDAY NIGHT. THE DURATION OF DEEPER MOISTURE
AND LIFT WILL BE GREATER SO WE ARE LIKELY TO SEE MORE IMPACTS.
THIS SYSTEM COULD CATCH PART OF THE THURSDAY EVENING AND FRIDAY
MORNING COMMUTES. ENSEMBLE MEAN ACCUMULATIONS ARE GENERALLY 1 TO
3 INCHES BUT THERE IS STILL A FAIR AMOUNT OF SPREAD AMONGST THE
MEMBERS.
- COLD WEEKEND
ARCTIC HIGH PRESSURE BUILDS INTO THE NORTHERN GREAT LAKES REGION
TO START THE WEEKEND. HERE IN LOWER MI WE WILL SEE AN EASTERLY
COMPONENT TO THE WINDS. THIS WILL ACT TO PUSH MOST OF THE LAKE
EFFECT SNOW AWAY FROM OUR CWA. TEMPS AT 925 MB FALL STEADILY INTO
SUNDAY MORNING. THE GFS SHOWS A 925 MB THERMAL TROUGH OF -10 DEG
C OVER GRR AT 12Z SUNDAY. WITH THE POSSIBILITY FOR FRESH SNOW AND
RELATIVELY CLEAR SKIES, WE WILL LIKELY END UP WITH A VERY COLD
NIGHT SATURDAY NIGHT. ENSEMBLE TEMPERATURE GUIDANCE HAS GENERALLY
BEEN TRENDING DOWNWARD FOR SATURDAY NIGHTS VALUES. WE WILL FEATURE
SINGLE DIGITS FOR MOST OF THE CWA.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1216 PM EST MON DEC 16 2024
LIFR CONDITIONS ARE LIKELY THIS AFTERNOON AS ABUNDANT LOW-LEVEL
MOISTURE LEADS TO LOW CIGS AND AREAS OF FOG, WITH VISBYS DOWN TO
1/2 MILE AT TIMES. LIFR CONDITIONS CONTINUE THROUGH THIS EVENING
WHEN A FRONT CROSSING THE AREA CLEARS OUT SOME OF THE LOW-LEVEL
MOISTURE. FOG DISSIPATES AND CIGS RISE TO IFR AND THEN MVFR THIS
EVENING BEHIND THE FRONT WITH MVFR CIGS AREAWIDE OVERNIGHT TONIGHT
INTO TUESDAY AFTERNOON. GUSTY WEST WINDS ARE ALSO EXPECTED WITH
10-15 KNOT WINDS GUSTING TO 15 KNOTS EXPECTED OVER THE TAF PERIOD.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 7 PM EST THIS EVENING FOR LMZ844>849.
SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR LMZ844>847.
SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR LMZ848-849.
DISCUSSION...MJS
AVIATION...THOMAS
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