811
FXUS63 KAPX 180414
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1114 PM EST FRI JAN 17 2025
KEY MESSAGES
- LIGHT MIX OF RAIN/SNOW INTO THIS EVENING WITH GUSTY WINDS.
- BITTERLY COLD TEMPERATURES/WIND CHILLS SUNDAY THROUGH TUESDAY.
- PERIODS OF LAKE EFFECT SNOW SATURDAY NIGHT - TUESDAY NIGHT
WITH SOME BLOWING/DRIFTING AND SIGNIFICANTLY REDUCED
VISIBILITY AT TIMES.
UPDATE
ISSUED AT 1108 PM EST FRI JAN 17 2025
AM BECOMING CONCERNED ABOUT MORE CONVECTIVE LOOKING BAND OF
PRECIPITATION CROSSING CENTRAL UPPER WITH THE POTENTIAL FOR A
BRIEF SNOW SQUALL WITH A BURST OF SNOW/WIND AND TEMPERATURES
FALLING BELOW FREEZING. SO WILL ISSUE A SECOND SPS FOR EASTERN
UPPER AND THE TIP OF THE MITT COUNTIES COVERING THIS SCENARIO IN
THE 06Z-09Z TIME FRAME.
ISSUED AT 1046 PM EST FRI JAN 17 2025
SYNOPSIS: 00Z SURFACE ANALYSIS SHOWS A 987MB CLIPPER LOW NORTH OF
LAKE SUPERIOR WITH A PAIR OF TRAILING COLD FRONTS...ONE ABOUT TO
CROSS INTO LAKE MICHIGAN WITH A SECONDARY BOUNDARY ACROSS WESTERN
UPPER/WISCONSIN/NORTHWEST IOWA. TEMPERATURES BEHIND THE SECOND
FRONT DROP INTO THE 20S WITH GUSTY NORTHWEST WINDS AS COLD AIR POURS
SOUTHWARD INTO THE MIDWEST/PLAINS. NARROW BAND OF VIRGA/LIGHT
PRECIPITATION STRETCHING FROM THE NORTH CHANNEL SOUTHWEST INTO
SOUTHERN WISCONSIN...DRIVEN BY LOW/MID LEVEL FRONTOGENESIS ALONG
INCOMING BAROCLINIC ZONE AND A WEAKER STABILITY PROFILE. LOW LEVELS
(BELOW 700MB) ARE RELATIVELY DRIER/HIGHER CLOUD BASES THUS
PRECIPITATION HAS BEEN LIGHT/SPOTTY. SOUTHERLY WINDS HAVE PUSHED
TEMPERATURES INTO THE LOWER 40S ACROSS NORTHWEST LOWER SO
PRECIP HAS BEEN FALLING AS RAIN OR A MIX OF RAIN/SNOW IN THE
LOWER ELEVATIONS... AND SNOW ACROSS THE HIGHER TERRAIN OF
NORTHERN LOWER.
FORECAST UPDATE: COLD FRONTS WILL PROGRESS ACROSS THE STATE OVERNIGHT...
SECONDARY FRONT WITH THE MAIN PUSH OF COLD AIR BEHIND IT SHOULD
BE INTO LAKE HURON BY DAYBREAK SATURDAY. WINDS WILL SHIFT TO
NORTHWEST AND BECOME GUSTY BEHIND THE SECOND FRONT. STRONG COLD
ADVECTION WILL LIKELY RESULT IN TEMPERATURES FALLING THROUGH THE
DAY.
SEVERAL PRECIPITATION AREAS TO TRACK TONIGHT: FIRST IS THE ONGOING
FRONTOGENETIC PRECIPITATION BAND LYING MOSTLY ACROSS NORTHERN LOWER
LIKELY TO PERSIST INTO THE EARLY MORNING HOURS. SECOND AREA OF
PRECIPITATION DEVELOPING IN THE VICINITY OF THE SECONDARY COLD FRONT
ACROSS LAKE SUPERIOR/CENTRAL UPPER THAT SHOULD SPREAD INTO EASTERN
UPPER AND THE TIP OF THE MITT COUNTIES TOWARD MIDNIGHT. EVENTUALLY
WILL SEE THE RETURN OF NORTHWEST FLOW LAKE CONVECTIVE BANDS DURING
THE EARLY MORNING HOURS. PRECIPITATION ALSO EXPECTED TO DEVELOP
ACROSS SOUTHERN LOWER AND PROPAGATE NORTHEAST TOWARD THE THUMB/
SAGINAW BAY REGION. CURRENT MIX OF RAIN AND HIGHER TERRAIN SNOW
SHOULD TRANSITION OVER TO ALL FROZEN PRECIPITATION AS COLDER AIR
ARRIVES. SOME CONCERNS OVER NORTHEAST LOWER WHERE ROAD TEMPERATURES
ARE AT OR A BIT BELOW FREEZING...ANY LIQUID PRECIPITATION ON THEM
MAY FREEZE AND CAUSE SOME SLICK SPOTS SO MAY PUT OUT A SPECIAL
WEATHER STATEMENT TO COVER THAT.
WINDS WILL PICK UP WITH PASSAGE OF THE SECOND COLD FRONT AFTER 06Z...
AND SHOULD BE PRETTY GUSTY ESPECIALLY WITH A STRONG ISALLOBARIC
COMPONENT ADDING A BIT OF A PUSH. GUSTS COULD EXCEED 40MPH FROM
THE NORTHWEST ESPECIALLY ACROSS EASTERN UPPER.
SHORT TERM /THROUGH SATURDAY/
ISSUED AT 208 PM EST FRI JAN 17 2025
PATTERN SYNOPSIS AND FORECAST:
HIGH PRESSURE CONTINUES TO SLIDE EASTWARD AS A LOW PRESSURE
TRACKS TO JAMES BAY BY LATE TONIGHT. SOUTHERLY WINDS USHERING IN
WARMER AIR AND A DECENT AMOUNT OF MOISTURE, HAVE PUSHED
TEMPERATURES INTO THE 30S AREA-WIDE CAUSING MIXED PRECIPITATION
TO BE OBSERVED AS SYNOPTICALLY DRIVEN SHOWERS ARE NOTICED ON
RADAR ACROSS NORTHWEST LOWER AND EASTERN UPPER. GUSTY WINDS WILL
DECREASE INTO TONIGHT, BUT REMAIN BREEZY AS THEY TURN NORTHWEST
BY MIDNIGHT TONIGHT AFTER A COLD FRONTAL PASSAGE. AFORMENTIONED
GUSTY WINDS WILL BRING THE POSSIBLE THREAT OF PATCHY BLOWING
SNOW DUE TO THE SIZE OF THE EXPECTED SNOWFALL AND THE "FLUFFY"
NATURE OF RECENT SNOWFALL, ESPECIALLY ACROSS OPEN AREAS TODAY
INTO SATURDAY. AS WINDS GAIN A NORTHERLY COMPONENT, LAKE EFFECT
SNOW SHOWERS ARE FORECASTED TO OCCUR LATE TONIGHT INTO SATURDAY.
MINIMAL ACCUMULATIONS ARE EXPECTED WITH GENERALLY AN INCH OF
SNOW EXPECTED FOR NORTHERN LOWER AND EASTERN UPPER BY SATURDAY
MORNING. LAKE EFFECT SHOWERS WILL CONTINUE INTO SATURDAY WITH
GENERALLY AN ADDITIONAL 1" T O 2" FORECASTED FOR NORTHWEST LOWER
AND EASTERN UPPER. HIGHEST AMOUNTS LOOK TO BE ACROSS EASTERN
UPPER WITH POTENTIALLY 3" POSSIBLE NEAR WHITEFISH BAY.
TEMPERATURES WILL TREND COLDER TONIGHT INTO SATURDAY AS COLD AIR
ADVECTS INTO THE NORTHWOODS. OVERNIGHT LOWS LOOK TO DROP INTO
THE TEENS TO LOWER 20S WITH DAYTIME HIGHS FOR SATURDAY LARGELY
IN THE MID TO LOW 20S.
LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/
ISSUED AT 208 PM EST FRI JAN 17 2025
PATTERN FORECAST: BY SATURDAY NIGHT, LONGWAVE TROUGHING IS
EXPECTED TO BE DRAPED PRETTY MUCH OVER THE ENTIRETY OF THE CONUS
WITH 500 MB HEIGHTS OVER THE MIDWEST SOME 2-3 SD BELOW THE MID-
LATE JANUARY MEAN. SFC LOW PRESSURE EXPECTED TO BE SPINNING NEAR
HUDSON BAY, AIDING TO DRAG A SECONDARY/REINFORCING COLD FRONT
ACROSS NORTHERN MICHIGAN. VERY COLD TEMPERATURES AND PERIODS OF
LAKE EFFECT SNOW ARE EXPECTED TO DOMINATE SUNDAY THROUGH AT
LEAST TUESDAY BEFORE TROUGHING BEGINS TO DIMINISH AND SHIFT EAST
BY MIDWEEK.
FORECAST DETAILS: COLD OVERNIGHT LOW TEMPS EXPECTED SATURDAY
NIGHT AS ARCTIC AIR REALLY BEGINS TO PUSH INTO THE GREAT LAKES
REGION -- RANGING FROM THE SINGLE DIGITS BELOW ZERO FAR NORTH
AND THROUGH THE SINGLE DIGITS ABOVE ZERO SOUTH OF THE BRIDGE. A
GRADUAL RAMP UP TO LAKE EFFECT SNOW SHOWERS ANTICIPATED THROUGH
SATURDAY NIGHT AS WELL, FAVORING THE TYPICAL WEST-NORTHWEST FLOW
SNOW BELTS OF BOTH EASTERN UPPER AND NORTHWEST LOWER MICHIGAN.
SUNDAY - TUESDAY FEATURE SIMILAR CONDITIONS WITH HIGHS ON
SUNDAY IN THE UPPER SINGLE DIGITS AND LOW TEENS. THE COLDEST
STRETCH EXPECTED TO BE SUNDAY NIGHT - TUESDAY WITH DAYTIME HIGHS
IN SINGLE DIGITS AND OVERNIGHT LOWS FALLING BELOW ZERO PRETTY
MUCH AREA-WIDE (COLDEST ACROSS INTERIOR AREAS AND IN THE EASTERN
U.P.). OCCASIONALLY BREEZY WINDS WILL KEEP APPARENT TEMPS BELOW
ZERO FOR MANY AREAS EVEN DURING THE DAY, AND IT'S POSSIBLE THAT
SOME LOCATIONS HAVE APPARENT TEMPS BELOW ZERO FROM SATURDAY
NIGHT ALL THE WAY THROUGH TUESDAY -- A SOLID 60-72 HOURS -- WITH
OVERNIGHT PERIODS FEATURING THE HIGHEST CHANCES FOR APPARENT
TEMPS TO FALL AS COLD AS -15 TO -25 F.
WHILE LAKE EFFECT SNOW WILL NO DOUBT CONTINUE THROUGH THE
DURATION OF THIS ARCTIC BLAST, THE MONDAY THROUGH TUESDAY TIME
FRAME APPEARS TO FEATURE THE GREATEST POTENTIAL FOR MOST
IMPACTFUL SNOW. FORECAST SOUNDINGS DISPLAY A DEEP CONVECTIVE
BOUNDARY LAYER UPWARDS OF 700MB AT TIMES, BUT ALMOST ENTIRELY AT
OR BELOW -20C. SO, WHILE SNOW SHOWERS MAY BE RATHER ROBUST AT
TIMES, SMALL FLAKE SIZE (COLUMNS/ PLATES VS. LARGE DENDRITES)
MAY LIMIT UPPER END EYE-POPPING ACCUMULATION, BUT RESULT IN
SIGNIFICANTLY REDUCED VISIBILITY AND TREACHEROUS TRAVEL AT TIMES
IN THE SNOW BELTS, ESPECIALLY FACTORING IN ANY WIND
EXACERBATING THESE ISSUES).
TEMPS BEGIN TO MODERATE INTO THE TEENS ON WEDNESDAY AND
EVENTUALLY TOWARD THE LOWER 20S BY THURSDAY. HOWEVER, LATEST
TRENDS SUPPORT A CLIPPER SYSTEM ARRIVING THROUGH THIS TIME FRAME
WITH ADDITIONAL CHANCES FOR MORE WIDESPREAD SNOW.
APX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST SATURDAY NIGHT FOR
LHZ345>349.
SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR LMZ323-341-342-
344>346.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST SATURDAY NIGHT FOR
LSZ322.
SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR LSZ321.
UPDATE...JPB
SHORT TERM...NSC
LONG TERM...MJG
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