536
FXUS63 KAPX 161140
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
640 AM 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
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 /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 639 AM EST THU JAN 16 2025
MAINLY MVFR CIGS ARE ANTICIPATED ACROSS NORTHERN MICHIGAN TAF SITES
THROUGH THIS MORNING INTO THIS AFTERNOON. CLOUD BASE HEIGHTS LOOK TO
GRADUALLY RISE THROUGH THE DAY, AND EVEN REACH VFR CONDITIONS FOR A
TIME TODAY -- MOST LIKELY AT APN AND PLN. A COLD FRONT WILL CONTINUE
TO SWING THROUGH THE AREA THIS MORNING, TURNING SOUTHWEST WINDS TO
NORTHWEST WINDS BY THIS AFTERNOON. SUSTAINED WINDS AROUND 10 KTS
WITH GUSTS BETWEEN 15-25 KTS ARE EXPECTED INTO THE EARLY EVENING
HOURS BEFORE WEAKENING TONIGHT.
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.
SHORT TERM...DJC
LONG TERM...FEF
AVIATION...DJC
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