526
FXUS63 KGRR 071140
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
640 AM EST SAT FEB 7 2026
KEY MESSAGES
- COLD THIS MORNING, LAKE EFFECT SNOW PUSHING OFFSHORE
- BRIEF BURST OF SNOW SUNDAY MORNING
- MODERATING TEMPERATURES NEXT WEEK WITH LOW CHANCES OF
PRECIPITATION
DISCUSSION
ISSUED AT 254 AM EST SAT FEB 7 2026
- COLD THIS MORNING, LAKE EFFECT SNOW PUSHING OFFSHORE
THE 07/00Z 850MB UPPER AIR MAP NICELY DEPICTED THE LOBE OF COLD
LOWER TROPOSPHERIC AIR SWINGING ACROSS MI, WITH APX REPORTING A
FROSTY -21C RIGHT ABOUT THE TIME THE THERMAL TROUGH WAS CROSSING THE
AREA. GRADIENT WINDS ARE STARTING TO RELAX, WHICH WILL ALLOW LAND
BREEZE MESOSCALE FORCING TO BECOME MORE PROMINENT; THIS WILL TURN
WINDS NEAR THE LAKESHORE TO AN OFFSHORE DIRECTION, PUSHING LES BANDS
OFFSHORE FROM SOUTHWEST LOWER MI. FARTHER NORTH TOWARDS US-10, LES
IS A BIT MORE PERSISTENT THANKS TO THE AGGREGATE EFFECT OF LAKES
SUPERIOR/MICHIGAN. HOWEVER, THIS TOO IS EXPECTED TO GRADUALLY TAPER
OFF EARLY TODAY. WE ARE SEEING A BIT MORE LAKE EFFECT CLOUDINESS
THAN EXPECTED AND THIS MAY RESULT IN SLIGHTLY MILDER MINIMUM
TEMPERATURES AND APPARENT TEMPERATURES THAN PREVIOUSLY THOUGHT.
NONETHELESS, MANY INLAND LOCATIONS COULD STILL SEE WIND CHILLS
BOTTOMING OUT AROUND MINUS 10 F THIS MORNING.
- BRIEF BURST OF SNOW SUNDAY MORNING
OUR NEXT SNOW WILL BE TONIGHT INTO EARLY SUNDAY MORNING BUT IS NOT
EXPECTED TO BE IMPACTFUL. A SUBTLE UPPER PV LOBE IS EXPECTED TO DROP
SOUTHEAST ACROSS THE AREA. THIS WILL BE IN THE RIGHT ENTRANCE REGION
OF THE UPPER JET WHERE MODERATELY AGEOSTROPHIC UPPER FLOW WILL
INDUCE BOTH MID-LEVEL ASCENT AND FRONTOGENESIS. THIS IS AN
INTERESTING CASE IN WHICH THE FGEN AXIS IS MORE OR LESS POINTED IN
THE SAME SOUTHEASTWARD DIRECTION THAT IT'S TRAVELING. THIS MEANS A
LONGER RESIDENCE TIME FOR SNOW WHICH WILL NUDGE UP ACCUMULATIONS.
HOWEVER, WE ARE NOT EXPECTING ANYTHING TOO CRAZY GIVEN THAT THE MID-
LEVELS APPEAR RELATIVELY STABLE; THIS WILL WEAKEN AND SPREAD OUT THE
UPWARD VERTICAL MOTION ASSOCIATED WITH THE RESPONSE TO FGEN. THERE
IS SIGNIFICANT DISPARITY AMONG THE SHORT RANGE MODELS ABOUT WHERE
THE PRESUMED NORTHWEST TO SOUTHEAST ORIENTED AXIS OF SNOW WILL BE
LOCATED. SOME MODELS PLACE IT RIGHT THROUGH SOUTHWEST LOWER MI WHILE
OTHERS PLACE IT SOUTH OF THE AREA. MAXIMUM AMOUNTS AROUND AN INCH
SEEMS TO BE THE CONSENSUS ALTHOUGH LOCALIZED AMOUNTS APPROACHING TWO
INCHES ARE NOT COMPLETELY OUT OF REACH.
- MODERATING TEMPERATURES NEXT WEEK WITH LOW CHANCES OF PRECIPITATION
AS NOTED BEFORE, WE ARE LOOKING AT A TRANSITION TO RIDGING FOLLOWED
BY A MORE ZONAL PATTERN WITH A PRONOUNCED UPPER JET ACROSS THE UPPER
MIDWEST AND GREAT LAKES, INDICATIVE OF AN UNDERLYING AND RELATIVELY
SHARP LOW LEVEL THERMAL/THICKNESS GRADIENT. THIS FAST ZONAL FLOW
PATTERN MAKES IT DIFFICULT TO ISOLATE WINDOWS OF GREATER
PRECIPITATION CHANCES, BUT IN GENERAL IT APPEARS THAT THE LATE WEEK
IS MORE FAVORED. THE EPS GENERALLY FAVORS SNOW FOR PRECIPITATION
TYPE THEN, BUT ABOUT 10 PERCENT OF ITS MEMBERS ALSO ADVERTISE
FREEZING RAIN. THIS WILL BE SOMETHING TO WATCH, BECAUSE ALTHOUGH
PROBABILITIES ARE LOW, THERE IS POTENTIAL FOR THIS TO CAUSE TRAVEL
IMPACTS.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 641 AM EST SAT FEB 7 2026
WE ESTIMATE A 10 PERCENT PROBABILITY OF ANY TERMINAL EXPERIENCING
IFR VISIBILITY OR CEILING RESTRICTIONS PRIOR TO 18Z AND A 20
PERCENT PROBABILITY OF THIS OCCURRING PRIOR TO 00Z TONIGHT.
THE ONLY CHANGE FOR THIS UPDATE WAS TO ADD SNOW SHOWERS WITH MVFR
VISIBILITY RESTRICTIONS AFTER 06Z TONIGHT. PRIOR TO THAT WE WILL
SEE FREQUENT MVFR CEILINGS IN THE NEIGHBORHOOD OF 3000 FT AGL. WE
DO NOT EXPECT FUEL ALTERNATE CEILINGS BELOW 2000 FEET TO OCCUR
TODAY.
GRR WATCHES/WARNINGS/ADVISORIES
MI...COLD WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MIZ039-040.
MARINE...NONE.
DISCUSSION...TJT
AVIATION...TJT
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