431
FXUS63 KAPX 161729
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1229 PM EST THU JAN 16 2025
KEY MESSAGES
- SNOW SHOWERS CONTINUE INTO TONIGHT. HIGHEST ACCUMULATIONS OF
1-3" FOR TYPICAL NORTHWEST FLOW LAKE EFFECT AREAS WITH 1" OR
LESS EXPECTED ELSEWHERE.
- COLD SUNDAY INTO EARLY NEXT WEEK.
- GUSTY WINDS FRIDAY.
- PERIODS OF SNOW INTO EARLY NEXT WEEK.
UPDATE
ISSUED AT 1115 AM EST THU JAN 16 2025
FORECAST REMAINS ON TRACK. RADAR AND SATELLITE IMAGERY DEPICT
ONGOING SNOW SHOWERS (SOME LOCALIZED MIXED PRECIP REPORTED)
AHEAD AND ALONG A COLD FRONT TRACKING ACROSS NORTHERN MICHIGAN
THROUGH THIS AFTERNOON. AS THE AFOREMENTIONED FRONT TRACKS
THROUGH, NW FLOW WILL LOCK ON HEADING LATE THIS AFTERNOON INTO
TONIGHT, SUPPORTING LAKE EFFECT SHOWERS FOR THE TYPICAL NW FLOW
SNOWBELTS. OBSERVATIONS ARE SHOWCASING WINDS ALREADY SHIFTING W
TO WNW WITH GUSTS TO 25MPH CLOSER TO THE SHORELINES. FOR MORE
DETAILS, PLEASE SEE SHORT-TERM DISCUSSION BELOW.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 422 AM EST THU JAN 16 2025
PATTERN SYNOPSIS:
STRONG TROUGHING WILL CONTINUE TO DIG ACROSS THE GREAT LAKES
AND OHIO VALLEY THIS MORNING, QUICKLY PUNCHING OVER THE EAST
COAST THIS AFTERNOON AND EVENING. THE ASSOCIATED CYCLONE OVER
HUDSON BAY WILL ALSO TREK EAST, SWINGING AN ATTENDANT COLD FRONT
ACROSS THE AREA THIS MORNING/EARLY AFTERNOON. BEHIND THIS,
RIDGING AND ASSOCIATED HEIGHT RISES OVERSPREAD THE GREAT LAKES
TONIGHT.
FORECAST DETAILS:
SNOW SHOWERS CONTINUE INTO TONIGHT -- ONGOING SNOW SHOWERS
ACROSS PARTS OF NORTHERN MICHIGAN ALONG AND AHEAD OF THE
APPROACHING COLD FRONT WILL CONTINUE TODAY INTO TONIGHT.
HEAVIEST SNOW OVER THE NEXT FEW HOURS WILL BE CONFINED CLOSE TO
THE LAKE MICHIGAN SHORELINE. AFTER THE FRONT PASSES, NORTHWEST
WINDS BEHIND THE BOUNDARY WILL LOCK IN AND SUPPORT LAKE EFFECT
SNOW SHOWERS. FORECAST SOUNDINGS SHOW AMPLE SATURATION IN LOW-
LEVEL PROFILES WITH QUALITY MOISTURE EXTENDING CLOSE TO 700MB
FOR LAKE EFFECT, DESPITE DELTA T'S ON THE MARGINAL SIDE. AN
ADDITIONAL 1-3" WILL BE POSSIBLE ACROSS TYPICAL NORTHWEST FLOW
LAKE EFFECT AREAS BY THIS EVENING WITH 1" OR LESS ANTICIPATED
ELSEWHERE. EXPECTATION IS THAT DIURNAL HEATING SHOULD KEEP BANDS
MORE CELLULAR IN NATURE, ALTHOUGH LESS OVER-LAKE INSTABILITY
AND STRONGER FLOW MAY HELP TO ORGANIZE ACTIVITY -- EVEN DURING
DAYLIGHT HOURS. THAT SAID, LOCALLY HIGHER AMOUNTS WILL BE
POSSIBLE SHOULD MORE ORGANIZED BANDING DEVELOP LATER THIS
MORNING AND AFTERNOON. LAKE EFFECT LOOKS TO FIGHT AN
INCREASINGLY HOSTILE ENVIRONMENT WITH TIME THIS EVENING AND
TONIGHT AS AFOREMENTIONED RIDGING MOVES IN AND DRIER AIR WORKS
INTO NORTHERN MICHIGAN, HELPING TO DIMINISH LAKE EFFECT BY
FRIDAY MORNING.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
ISSUED AT 422 AM EST THU JAN 16 2025
PATTERN SYNOPSIS/FORECAST:
NW FLOW ALOFT OVERTAKING THE UPPER MIDWEST...AS PV MAXIMA
SWIRLS DOWN INTO ONTARIO TOWARD LAKE SUPERIOR. RIDGING REMAINS
FIRMLY IN PLACE OVER THE NW US COAST, EVEN AS ADDITIONAL ENERGY
PUNCHES INTO BRITISH COLUMBIA; UPPER LOW REMAINS LOCKED IN OFF
BAJA CALIFORNIA WITH CONTINUED EASTERLY FLOW OVER SOCAL IN REX
BLOCK. COL REGION OVER NM INTO TX...WITH A PV MAX TREKKING
THROUGH THE GULF COAST STATES...AND RIDGING OVER THE NE US AHEAD
OF INITIAL SHORTWAVE AXIS JUST DEPARTING MI AS OF EARLY THIS
MORNING. MOISTURE STARTING TO DEEPEN OVER THE MIDWEST WITH THIS
LATTER SHORTWAVE AXIS/CLIPPER SYSTEM...THOUGH BETTER MOISTURE
REMAINS UPSTREAM, FROM ALBERTA DOWN INTO THE CENTRAL
PLAINS...BEHIND WARM FRONT STRETCHING FROM ONTARIO DOWN INTO THE
MID MS VALLEY. COLD AIR TO BE REINFORCED BEHIND THIS
CLIPPER...WITH 850MB TEMPS OF -8C AND COLDER IN ITS WAKE OVER
NORTHERN ONTARIO...NORTH OF OCCLUDED SURFACE FRONT AND DYING
COLD FRONT STRETCHING FROM HUDSON BAY TOWARD LAKE WINNIPEG.
BEHIND THIS CLIPPER...RIDGING AND WARMER AIR TAKES OVER THE
MIDWEST FOR A BRIEF PERIOD TONIGHT...AHEAD OF SHORTWAVE DIVING
OVER THE WESTERN RIDGE THROUGH WESTERN CANADA. AS RIDGING
REBUILDS IN ITS WAKE...WILL EXPECT NORTHERLY FLOW TO
DRAMATICALLY DEEPEN OVER CENTRAL CANADA INTO THE NORTHERN US TO
WRAP UP THE WORK WEEK AND START OUT THE WEEKEND AS SOUTHWESTERN
BLOCKY LOW FINALLY SEEMS TO DEPART EASTWARD ACROSS THE SOUTHERN
US. ULTIMATE RESULT: BROAD TROUGHING OVERTAKES THE BULK OF THE
CONUS THIS WEEKEND INTO EARLY NEXT WEEK. FIRST WAVE EXPECTED TO
SWING IN LATE FRIDAY INTO SATURDAY, BRINGING A LITTLE BIT OF
SLIPPERY SNOW AND GUSTY WINDS, FOLLOWED BY A SHOT OF LAKE EFFECT
SATURDAY...WITH A REINFORCING SHOT OF COLD AIR SLOWLY PLOWING
IN FOR SUNDAY INTO MONDAY AS WE START TO TAP INTO SOME
ARCTIC/POLAR AIR...RAMPING UP THE LAKE EFFECT MACHINE AS WE GO
INTO THE END OF THE WEEKEND AND BEYOND. INCREASING UNCERTAINTY
IN THE PATTERN BEYOND THIS...THOUGH THERE IS SOME SIGNAL FOR THE
UPSTREAM PATTERN TO BREAK DOWN A BIT GOING TOWARD THE MIDDLE OF
THE WEEK, WHICH /SHOULD/ RESULT IN A BIT OF A MODERATION, AT
LEAST FOR A TIME...WITH UNCERTAINTY IN WHETHER OR NOT/HOW
QUICKLY TROUGHING MAY TRY TO SETTLE BACK INTO THE CENTRAL US
LATE NEXT WEEK.
PRIMARY FORECAST CONCERNS:
COLD SUNDAY INTO EARLY NEXT WEEK...ENSEMBLE GUIDANCE
HIGHLIGHTING ANOMALOUSLY COLD TEMPS FOR THIS NEXT
OUTBREAK...850MB TEMPS RUNNING BELOW THE 5TH PERCENTILE (VERY
LOW END OF CLIMO) OVER PARTS OF THE MIDWEST (AND INTO THE
SOUTHERN US) THROUGH THE WEEKEND INTO EARLY NEXT WEEK. INCOMING
AIR MASS CERTAINLY SUPPORTIVE OF HIGHS IN THE SINGLE DIGITS
ABOVE ZERO TO AROUND +10F EARLY NEXT WEEK (COLDER UPSTREAM,
HOWEVER); SAVING GRACE FOR OUR NECK OF THE WOODS, TEMPERATURE
WISE, WILL LIKELY BE REINFORCEMENT OF LAKE AGGREGATE TROUGHING
AND CLOUD COVER TO KEEP DIURNAL SWINGS MINIMIZED (AT LEAST FOR
THE TYPICAL LAKE AREAS)...AND THEORETICALLY KEEP LOWS FROM
BOTTOMING OUT AS COLD AS THEY OTHERWISE MIGHT...THOUGH MAY NEED
TO KEEP AN EYE ON THIS FOR AREAS AWAY FROM THE LAKE BANDS THAT
COULD SEE SOME CLEARING. TYPICAL DIURNAL TEMP SWING THIS TIME OF
YEAR IS 10-15 DEGREES, WHICH WOULD RATHER EASILY PUT LOWS AT OR
BELOW ZERO, EVEN WITH SOME CLOUD COVER AROUND. SUSPECT THAT
WITH THE COLD AIR MASS OVERHEAD...EVEN DAYTIME HIGHS COULD
STRUGGLE TO RECOVER INTO THE SINGLE DIGITS ABOVE ZERO WITH CLOUD
COVER OVERHEAD TO PRECLUDE BETTER DIURNAL "HEATING"...WHICH
COULD FEEDBACK A BIT INTO COLDER NIGHTS BEFORE RIDGING RETURNS
AND THE PATTERN TRIES TO MODERATE TOWARD THE MIDDLE OF NEXT
WEEK. NOT IMPOSSIBLE THAT WE COULD SEE DRAINAGE FLOW INTO THE
EUP AS WELL, WHICH WOULD DROP THINGS EVEN FURTHER FOR THAT
REGION IN PARTICULAR...THOUGH FOR NOW, THINK WINDS SHOULD REMAIN
UP A BIT, ALSO PERHAPS LIMITING THE AMOUNT OF BOTTOMING OUT WE
CAN DO WITH OVERNIGHT LOWS.
ULTIMATELY, CERTAINLY POSSIBLE WE COULD BE LOOKING AT A PERIOD
OF COLD WEATHER ADVISORIES FOR EARLY NEXT WEEK...GIVEN THE VERY
COLD ACTUAL AIR TEMPERATURES EXPECTED, AS WELL AS AFOREMENTIONED
WINDS REMAINING UP A BIT (THANKS TO LAKE AGGREGATE
TROUGHING)...LEADING TO POTENTIAL FOR WIND CHILLS AT OR BELOW
-20C ACROSS THE EUP, ESPECIALLY DURING THE OVERNIGHTS, AND
CLOSING IN ON -15C FOR NORTHERN LOWER IN SPOTS.
GUSTY WINDS FRIDAY...THINK WE WILL HAVE A QUICK SHOT AT
BREEZY/GUSTY CONDITIONS WITH THE FRONT PASSING THROUGH FRIDAY.
STRONG 850MB LLJ (40-50+KTS), AND EVEN 925MB WINDS AROUND 30+KTS
SUPPORTIVE OF GALES, NOTING THAT WE WILL HAVE THE WELL-MIXED
MARINE LAYER (THANKS ANOMALOUSLY WARM LAKE SURFACE TEMPS) TO
CONTEND WITH DESPITE WARM ADVECTION. THEREFORE, THINK IT'S
ENTIRELY POSSIBLE WE COULD MIX DOWN SOME OF THESE STRONGER WINDS
ALOFT, PER GUIDANCE SOUNDINGS SUGGESTING A MIXED LAYER DEEP
ENOUGH TO TRY FOR THIS IDEA; THINK THERE COULD BE A
SNEAKY/SUBTLE ISALLOBARIC COMPONENT TO BOOST WINDS A BIT WITH
FROPA AS WELL. ANTICIPATE GUSTS 25-30KTS AREAWIDE FRIDAY INTO
EARLY FRIDAY NIGHT, AND WILL HAVE TO MONITOR THAT POTENTIAL FOR
A FEW-HOUR-PERIOD OF GUSTS INTO THE 40-50+KT RANGE FRIDAY
AFTERNOON IN PARTICULAR...THOUGH CONFIDENCE OF THIS IS ON THE
LOWER SIDE ATTM.
PERIODS OF SNOW INTO EARLY NEXT WEEK...SOME SW FLOW LAKE
ENHANCEMENT POSSIBLE FOR THE EUP FRIDAY AHEAD OF THE FRONT,
PARTICULARLY IN THE AFTERNOON/EVENING AHEAD OF THE PRIMARY
FRONT...THOUGH DO EXPECT SOMEWHAT MORE WIDESPREAD SNOW/BAND OF
SNOW TO CROSS THE AREA THROUGH THE NIGHT. NOT IMPOSSIBLE THERE
COULD BE SOME FREEZING DRIZZLE AT TIMES (OR EVEN SOME PLAIN RAIN
WHERE IT'S WARM ENOUGH), NOTING WE WILL BE WARM AND THERE COULD
BE SOME TIMES WHERE WE AREN'T SATURATED ENOUGH FOR ICE
NUCLEI...THOUGH AFOREMENTIONED INCREASING MOISTURE ALOFT SHOULD
PUT A STOP TO THAT IDEA (IF THAT IDEA EVEN COMES TO FRUITION) BY
LATE AFTERNOON/EVENING AND BEYOND AS THE FRONT COMES THROUGH.
THIS SNOWFALL SHOULD BE A LITTLE WETTER/GREASIER, THANKS TO
AFOREMENTIONED WARMER TEMPS...WHICH COULD LEAD TO SOME TRICKY
TRAVEL AT TIMES, EVEN WITH ONLY A LITTLE SNOW.
LAKE EFFECT RAMPS UP THIS WEEKEND WITH THE EXPECTED COLD
ADVECTION AND SUBSEQUENT INCREASE IN OVERLAKE INSTABILITY.
INVERSION HEIGHTS LOOKING TO RISE INTO THE 6000-9000FT RANGE
THROUGH THE WEEKEND, SUPPORTIVE OF DEEPER LAKE CONVECTION.
PRIMARY FLOW SHOULD BE NORTHWESTERLY...THOUGH WILL EXPECT SOME
WIND SHIFTS FROM W TO NW AT TIMES AS VARIOUS PV NIBLETS SWING
THROUGH TO REINFORCE THE COLD AIR. SIGNALS ATTM HINTING AT
POTENTIAL FOR A STRONGER BAND OF SNOW TO IMPACT WESTERN AND/OR
CENTRAL CHIPPEWA COUNTY SATURDAY INTO AT LEAST SUNDAY...WHERE
CONVERGENCE COULD BE MAXIMIZED WITH THE STRENGTHENING OF THE
LAKE AGGREGATE TROUGH, AND WILL MONITOR THIS GOING FORWARD.
THERMAL PROFILES SUGGEST WE COULD BE LOOKING AT A BIT MORE
POWDERY SNOW AND/OR DENDRITES, SIMILAR TO RECENT BURSTS OF COLD
LAKE EFFECT. FOR NOW...NOT NECESSARILY EXPECTING ANY SUPER
DRAMATIC SNOW-DUMPS (I.E., NOT EXPECTING TO REPEAT THANKSGIVING
WEEKEND '24)...BUT CERTAINLY POSSIBLE THE SNOW COULD ADD UP OVER
THE COURSE OF A FEW DAYS, PARTICULARLY BY EARLY NEXT WEEK.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1228 PM EST THU JAN 16 2025
MVFR CONDITIONS WITH IFR VISIBILITIES AT TIMES ARE EXPECTED TO
CONTINUE FOR MAINLY KTVC AND KCIU. OTHER SITES ARE EXPECTED TO
GRADUALLY SEE AN IMPROVING TREND IN CONDITIONS AS THE DAY
PROGRESSES AND SNOW SHOWERS BECOME MORE LAKE EFFECT INDUCED,
TARGETING THE NW FLOW SNOWBELTS. SUSTAINED WINDS AROUND 10 KTS
WITH GUSTS BETWEEN 15- 25 KTS ARE EXPECTED INTO THE EARLY
EVENING HOURS BEFORE WEAKENING TONIGHT AHEAD OF GUSTY SW WINDS
RETURNING FRIDAY WITH GUSTS TO 30 KTS POSSIBLE.
APX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR LHZ345>349.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LMZ323-
341-342-344>346.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LSZ321-
322.
UPDATE...NSC
SHORT TERM...DJC
LONG TERM...FEF
AVIATION...NSC
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