717
FXUS63 KAPX 042337
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
637 PM EST SUN JAN 4 2026
KEY MESSAGES
- IMPACTFUL SNOW TONIGHT WITH PASSING SHORT WAVE TROUGH/WARM
ADVECTION.
- ADDITIONAL PRECIPITATION CHANCES WITH QUICK MOVING
DISTURBANCES TUESDAY/WEDNESDAY.
- MID/LATE WEEK WARMING TREND.
- MORE WEEKEND STORM POTENTIAL? TRENDS ARE LEANING THAT WAY...
DISCUSSION
ISSUED AT 305 PM EST SUN JAN 4 2026
PATTERN SYNOPSIS/FORECAST: LARGE SCALE PATTERN FEATURES HIGH-
LATITUDE -NAO BLOCKING FROM EASTERN CANADA INTO EUROPE; LONG WAVE
TROUGH AXIS ASSOCIATED WITH THE WESTERN PORTION OF THE BLOCK
STRETCHES DOWN THE EAST COAST INTO THE GULF. BROAD LONG WAVE RIDGE
LIES ACROSS THE NATION'S MIDSECTION/CANADIAN PRAIRIE PROVINCES...
WITH A -PNA TROUGH JUST OFF THE WEST COAST OF NORTH AMERICA. COLD
POLAR AIR INCREASINGLY CONFINED TO EASTERN CANADA/NEW ENGLAND WITH
MORE PACIFIC-ORIGIN AIR SPREADING ACROSS THE WESTERN/CENTRAL CONUS.
WATER VAPOR IMAGERY SHOWS A SHORT WAVE TROUGH/HEIGHT FALLS EMERGING
FROM THE NORTHERN ROCKIES INTO THE MEAN RIDGE POSITION...WITH RISING
HEIGHTS AHEAD OF IT ACROSS THE MIDWEST/GREAT LAKES (+80M/12H 500MB
HEIGHT CHANGE ON 1200Z APX SOUNDING). STILL DEEP LAYER NORTHWEST
FLOW ACROSS MICHIGAN INITIALLY (AND STILL -14C AT 850MB AT APX THIS
MORNING)...THOUGH STRONG LOW/MID LEVEL WARM ADVECTION UNDERWAY
ACROSS THE MIDWEST/NORTHERN AND CENTRAL PLAINS. AT THE SURFACE A
NARROW/ELONGATED HIGH PRESSURE RIDGE EXTENDS FROM NORTHERN
MANITOBA...THROUGH THE UPPER GREAT LAKES AND INTO THE MISSISSIPPI
VALLEY. A BIT OF A LAKE AGGREGATE TROUGH LINGERING OVER THE
GREAT LAKES...WITH COLD AIR HORSESHOEING AROUND THE UPPER LAKES.
ELONGATED LEE SIDE TROUGHING DOWNWIND OF THE NORTHERN/CENTRAL
ROCKIES.
PATTERN ACROSS THE CONUS TURNS A BIT MORE ZONAL FOR THE FIRST PART
OF THE WEEK AS WEST COAST TROUGH SPLITS...LEAVING SOME ENERGY BEHIND
OFF BAJA CALIFORNIA. INITIAL SHORT WAVE TROUGH MOVING THROUGH THE
CENTRAL NORTH AMERICA LONG WAVE RIDGE POSITION WILL CROSS THE GREAT
LAKES DURING THE FIRST HALF OF MONDAY. ANOTHER PIECE OF ENERGY WILL
GET KICKED OUT OF THE SOUTHERN BRANCH PORTION OF THE WEST COAST
TROUGH...ALONG WITH PERHAPS A NORTHERN BRANCH COUNTERPART. THESE
WAVES WILL MOVE THROUGH THE GREAT LAKES/OHIO VALLEY IN THE
TUESDAY/WEDNESDAY TIME FRAME. PATTERN THEN BECOMES MORE
AMPLIFIED DURING THE LATTER HALF OF THE WEEK WITH LONG WAVE
TROUGHING DEVELOPING OVER CENTRAL NORTH AMERICA. QUESTIONS ON
HOW THIS TROUGH EVOLVES REGARDING FLOW "ALLOCATION" BETWEEN
NORTHERN AND SOUTHERN BRANCHES WILL HAVE IMPACTS ON SENSIBLE
WEATHER FOR NEXT WEEKEND...AT THE VERY LEAST IT DOES LOOK
UNSETTLED.
LEAD SHORT WAVE TROUGH COMING THROUGH EARLY MONDAY WON'T HAVE MUCH
OF A SURFACE REFLECTION WITH IT AS UPPER LEVEL FEATURE QUICKLY
OUTRUNS A WEAK ATTEMPT AT LEE CYCLOGENESIS. SOUTHERN BRANCH WAVE
FOR TUESDAY EXPECTED TO HAVE A LITTLE BETTER SURFACE REFLECTION...
WITH A LEE SIDE LOW THAT DEVELOPS OVER KANSAS AND EVENTUALLY
PROPAGATES ACROSS SOUTHERN LOWER. BY FRIDAY LOOKING AT ANOTHER LEE
SIDE CYCLONE EMERGING FROM THE CENTRAL/SOUTHERN PLAINS THAT MAY
EVOLVE INTO A STRONGER CYCLONE THAT IMPACTS THE GREAT LAKES FOR THE
WEEKEND.
PRIMARY FORECAST CONCERNS:
IMPACTFUL SNOW TONIGHT WITH PASSING SHORT WAVE TROUGH/WARM
ADVECTION: SOME LINGERING SNOW SHOWERS OFF LAKE SUPERIOR THIS
AFTERNOON MAINLY AROUND WHITEFISH BAY...AND FLURRIES OFF LAKE
MICHIGAN WITH LINGERING SHALLOW INSTABILITY. TONIGHT'S SNOW EVENT
GETTING BETTER ORGANIZED WITH INCREASING RADAR RETURNS ACROSS
NORTHWEST ONTARIO/MINNESOTA... WITH A NUMBER OF FACTORS COMING
TOGETHER TO DRIVE THIS EVENT INCLUDING ISENTROPIC ASCENT...LOW/MID
LEVEL FRONTOGENESIS AND SHORT WAVE TROUGH PROVIDING DYNAMIC SUPPORT.
ALL OF THIS AHEAD OF STEEPER MID LEVEL LAPSE RATES WHICH WILL
HELP PROVIDE A BETTER UPWARD MOTION RESPONSE TO THE GIVEN
FORCING. COLUMN SATURATION SHOULD COME FROM THE TOP DOWN AS IS
OCCURRING UPSTREAM SO INITIAL PRECIPITATION WILL GO INTO THAT
BUT LOOKS LIKE BETTER SNOW SHOULD MOVING INTO WESTERN PORTIONS
OF THE FORECAST AREA AROUND 0200Z (WILL NOT CHANGE HEADLINE
START TIMES TO ACCOUNT FOR THIS). AFTER AROUND 0700Z OR SO MID
LEVEL MOISTURE WILL BEGIN TO STRIP OUT...LEAVING BEHIND A
SATURATED LAYER BELOW 700MB BUT AT TEMPERATURES WARMER THAN -10C
WHICH SUGGESTS POSSIBLE ISSUES WITH ICE NUCLEATION AND PRECIP
TAPERING TO SOME COMBINATION OF FREEZING DRIZZLE/VERY LIGHT
FREEZING RAIN (GIVEN THE DEPTH OF THE MOISTURE LEFT BEHIND)/OR
LIGHT SNOW/FLURRIES FROM SOUTHWEST TO NORTHEAST THROUGH DAYBREAK
MONDAY (SNOW AT LEAST ACROSS EASTERN UPPER LIKELY TO PERSIST
THROUGH THEN). MADE SOME SMALL ADJUSTMENTS TO THE LIQUID PRECIP
FORECAST BUT STILL LOOKING AT A NICE QUICK HITTING EVENT...AS
MENTIONED IN THIS SPACE YESTERDAY SNOW CONSISTENCY SHOULD BE A
BIT MORE DENSE/LOWER SLR DUE TO THE THERMAL PROFILE...BUT THE
DGZ WHILE RELATIVELY NARROW DUE TO THE LAPSE RATES COULD OFFER
SOME STRONGER VERTICAL MOTION THROUGH THE LAYER GIVEN THE WEAKER
STABILITY PROFILE. OVERALL HAVE A SOUTHWEST-NORTHEAST ORIENTED
SLR GRADIENT RANGING FROM AROUND 10:1 TO 16:1...RESULTING IN 12H
SNOWFALL TOTALS (0000-1200Z) OF 4-8 INCHES ROUGHLY NORTH OF A
LELAND-KALKASKA- TAWAS CITY LINE...AND FROM 2 TO 4 INCHES SOUTH
OF THERE WITH A LOWER SLR AND AN EARLIER SWITCH TO FREEZING
DRIZZLE/ FLURRIES.
ONLY CHANGE TO HEADLINES WILL BE GEOGRAPHIC...ADDING IN
MANISTEE DUE TO THE FREEZING DRIZZLE POTENTIAL. EXPECT SOME
LOCALES TO PUSH WARNING CRITERIA SNOWFALL ESPECIALLY EAST OF
I-75/NORTH OF M- 55 WHERE WARNING CRITERIA FOR SNOWFALL IS LOWER
(7"/24H VERSUS 8"/24H IN THE LAKE SNOWBELTS). ALSO WHY SOUTHERN
SCHOOLCRAFT HAS BEEN UPGRADED TO A WARNING SINCE THEIR CRITERIA
IS ONLY 6" VERSUS 8" FOR MACKINAC COUNTY (BEFORE YOU ASK). NOT
ANTICIPATING BLOWING/ DRIFTING SNOW TO BE A BIG FACTOR...BUT
WITH SNOWFALL RATES IN THE 1+"/HR RANGE VISIBILITIES BELOW 1/2
MILE ARE LIKELY NORTH OF M-72 JUST FROM FALLING SNOW. SNOW WILL
PROBABLY LINGER INTO THE DAYLIGHT HOURS MONDAY FOR EASTERN
UPPER/NORTHEAST LOWER AS LAST BIT OF FORCING/DEEPER MOISTURE
ASSOCIATED WITH THE SHORT WAVE TROUGH MOVES THROUGH. THREAT FOR
FREEZING DRIZZLE/DRIZZLE LIKELY ENDS FROM WEST TO EAST DURING
THE AFTERNOON.
ADDITIONAL PRECIPITATION CHANCES WITH QUICK MOVING DISTURBANCES
TUESDAY/WEDNESDAY: ANOTHER SLIGHTLY STRONGER SHORT WAVE TROUGH AND
ATTENDANT SURFACE LOW WILL MOVE THROUGH LOWER MICHIGAN DURING THE
DAY TUESDAY...BRINGING ANOTHER ROUND OF PRECIPITATION. DEFINITELY A
WINTRY MIX LOOK TO THE EVENT WITH QUESTIONS REGARDING THE THERMAL
PROFILE...PROBABILITY SPACE SUGGESTS A RAIN/FREEZING RAIN TO
SNOW/WINTRY MIX TRANSITION. SO WILL HAVE TO ACCOUNT FOR THIS IN
AFTERNOON MESSAGING.
MID/LATE WEEK WARMING TREND: ZONAL FLOW BECOMING MORE AMPLIFIED
DURING THE LATTER HALF OF THE WEEK WILL KEEP THE COLD AIR AT BAY...
WITH ABOVE NORMAL TEMPERATURES EVEN BY TUESDAY. HIGHS IN THE 40S
APPEAR IN THE CARDS ESPECIALLY ON THURSDAY; RECORD HIGHS FOR
THURSDAY INCLUDE 41 ANJ/45 PLN/47 GLR/49 TVC/50 APN/52 HTL BUT
THOSE LOOK SAFE BASED ON CURRENT FORECAST TRENDS.
MORE WEEKEND STORM POTENTIAL? TRENDS ARE LEANING THAT WAY...: AS
MENTIONED ABOVE THE WEEKEND IS LOOKING UNSETTLED WITH FORECAST
TRENDS HONING IN ON ANOTHER STRONG SYSTEM ACROSS THE GREAT LAKES
REGION...AND TRACK WILL ULTIMATELY DEPEND ON WHETHER THIS IS AN ALL
SNOW EVENT OR DO WE GET TO PLAY AROUND WITH PRECIPITATION TYPES? BUT
ANOTHER SYSTEM THAT BEARS WATCHING IN A WINTER THAT SEEMS SORT OF
RELENTLESS AT THIS POINT.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 637 PM EST SUN JAN 4 2026
IFR CONDITIONS DEVELOP EARLY TONIGHT, AS A SWATH OF SNOW PUSHES
INTO AND ACROSS THE AREA. THIS WILL BE A RELATIVELY HEAVY/WET
SNOW COMPARED TO RECENT EVENTS, SNOW/LIQUID RATIOS IN THE LOWER
TEENS TO NEAR 10:1. LOW CIGS (AND PERHAPS FZDZ/DZ) WILL LINGER
INTO MONDAY AFTER THE SNOW EXITS (MVFR TO IFR). SOUTHERLY WINDS
INCREASE TONIGHT AT THE MORE SOUTHERN TAF SITES (MBL/TVC),
OTHERWISE WINDS ARE ON THE LIGHT SIDE.
APX WATCHES/WARNINGS/ADVISORIES
MI...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR MIZ016-017-
020>022-025>028-031>034-086>088-095>099.
WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR MIZ018-023-
024-029-030-035-036-041-042.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST
MONDAY FOR LMZ345-346.
SHORT TERM...JPB
LONG TERM...JPB
AVIATION...JZ
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page