866
FXUS63 KAPX 170908
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
408 AM EST MON FEB 17 2025
KEY MESSAGES
- ACCUMULATING LAKE EFFECT SNOW INTO TUESDAY. BRISK WINDS WILL
LEAD TO SOME BLOWING SNOW AND QUICK DROPS IN VISIBILITY.
- BITTER COLD WIND CHILLS THROUGH THE FIRST HALF OF THE WEEK.
- TEMPERATURES LIKELY TO REBOUND BY THE WEEKEND.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 407 AM EST MON FEB 17 2025
PATTERN/SYNOPSIS: DEEP LOW PRESSURE WILL REMAIN NEAR NEW
BRUNSWICK TODAY, BEFORE EXITING EASTWARD TONIGHT. VERY COLD AIR
CONTINUES TO INVADE THE NORTHERN LAKES, RESULTING IN LAKE
AGGREGATE TROFFING OVER NORTHERN LK HURON AND SE SUPERIOR.
ALOFT, A 500MB CLOSED WILL GRADUALLY FILL CROSSING SUPERIOR
TODAY, OPENING UP INTO A SHARP TROF TONIGHT.
FORECAST: COLD ADVECTION CONTINUES TODAY. BY EARLY EVENING, 850MB
TEMPS REACH -23/-24C, AND REMAIN THERE TONIGHT. ABUNDANT
INSTABILITY FOR LAKE EFFECT PROCESSES OF COURSE, AND MODERATE TO
AT TIMES HEAVY BANDING IS ALREADY OCCURRING IN THE NORTHERN
LAKES. SOME VERY SKINNY STRONGER BANDLETS ARE IN PLACE IN
NORTHERN LOWER MI (EASTERN CHARLEVOIX CO AND NE KALKASKA CO, IN
PARTICULAR). A MORE NORTHERLY FETCH ON SUPERIOR IS FOCUSING
BANDING INTO EASTERN ALGER CO (AND IS THE ULTIMATE ORIGIN OF THE
NORTHERN LOWER MI BANDS).
MOISTURE AVAILABILITY IS SPARSE, IN BOTH A RELATIVE AND
ABSOLUTE SENSE. OUTSIDE OF LAKE EFFECT CLOUDS, SKIES ARE LARGELY
CLEAR, THOUGH SOME COLDER CLOUDS ARE SEEN NORTH OF SUPERIOR.
MODELS ARE SHOWING A SLIGHT MOISTURE INCREASE LATE TONIGHT IN
EASTERN UPPER MI, ASSOCIATED WITH THOSE COLDER CLOUD TOPS.
ANOTHER LIMITING FACTOR: THE DGZ WILL BE VERY SHALLOW AND VERY
LOW TO THE GROUND. STRONGER BANDS WILL STILL HAVE OK DENDRITE
GENERATION TODAY, ESPECIALLY EARLY. BUT OTHERWISE SNOWFLAKES
WILL TURN SMALLER/ POWDERY. THAT HURTS SLRS AND SNOW ACCUMS,
THOUGH THE SMALL FLAKES ARE EASIER TO BLOW AROUND IN OUR BRISK
NW WINDS.
SNOW SHOWER COVERAGE WILL INCREASE BY LATE MORNING, AS DIURNAL
'HEATING' FURTHER STEEPENS LOW-LEVEL LAPSE RATES. ACCUMS WILL BE
BROADLY 1-3" TODAY IN THE SNOWBELTS (WNW/NW IN NORTHERN LOWER,
NW/NNW IN EASTERN UPPER MI). LOCALLY HIGHER AMOUNTS REMAIN
POSSIBLE. HAVE EXTENDED THE NW LOWER MI ADVISORY INTO THIS
EVENING. THOUGH THE FLOW IS A BIT TOO NORTHERLY (AND UPSTREAM
WATERS TOO ICY) FOR WESTERN CHIP CO TO BE HIT HARD, WESTERN MACK
CO WILL BE IMPACTED BY THE STRONGER BANDING COMING ONSHORE TO
THE WEST. HAVE ISSUED AN ADVISORY FOR THE WESTERN MACK CO ZONE.
WILL ALSO NEED TO KEEP AN EYE ON THE PRESQUE ISLE CO COAST
TODAY.
TONIGHT, WINDS TO VEER SOMEWHAT ON SUPERIOR, AND LAKE EFFECT
SHOULD MAKE MORE OF A PUSH IN WESTERN CHIP CO. 2-5" FORECAST
THERE AND IN FAR NW MACK CO. KALKASKA CO AND NEARBY COUNTIES
SHOULD BE THE MAIN FOCUS IN NW LOWER MI, WITH 2-5" TOTALS THERE
AS WELL. UP TO 2" IN THE BROADER SNOWBELTS. WILL LET LATER
SHIFTS EVALUATE TRENDS FURTHER, AND THE POTENTIAL NEED FOR
ADVISORIES TONIGHT. ALSO: WIND CHILLS DROPS TO MID MINUS TEENS
IN N CENTRAL AND NE LOWER MI LATE TONIGHT, AND PERHAPS -20 AT
THE SAULT. THIS REACHES "COLD WEATHER ADVISORY" THRESHOLDS IN
BOTH AREAS, AND SUCH HEADLINES ARE DISTINCTLY POSSIBLE LATER
ON.
HIGH TEMPS TODAY NEAR 10 ABOVE TO THE MID TEENS. LOWS TONIGHT
SLIGHTLY ABOVE ZERO NEAR LAKE MI, TO AS COLD AS -10F NEAR THE
SAULT.
LONG TERM /TUESDAY THROUGH SUNDAY/
ISSUED AT 407 AM EST MON FEB 17 2025
PATTERN SYNOPSIS/FORECAST:
COLD ARCTIC AIR WILL CONTINUE TO ADVECT INTO THE NORTHWOODS WITH THE
CORE OF COLDEST AIR REACHING NORTHERN MICHIGAN MONDAY/TUESDAY.
NORTHWEST WINDS LOOK TO PERSIST AS PRESSURE GRADIENTS ORIENT
NORTHWEST FROM A DEPARTING LOW PRESSURE SYSTEM AND HIGH PRESSURE
TRYING TO BUILD IN ITS WAKE. COLD AIR SEEPING INTO THE REGION, ALONG
WITH AFORMENTIONED PERSISTENT NORTHWEST FLOW, WILL POTENTIALLY KEEP
LAKE EFFECT SNOW SHOWERS LINGERING THROUGH MID-WEEK. WITH MOISTURE
SLOWLY BEING ERODED AWAY BY THE AFOREMENTIONED COLD AIR AND WRAP
AROUND MOISTURE IN SHORTER SUPPLY AS THE AFORMENTIONED LOW PRESSURE
DEPARTS, THIS SHOULD KEEP SNOW AMOUNTS LIGHTER. ALL THIS TO SAY, THE
TYPICAL NW FLOW SNOWBELTS CAN PROBABLY EXPECT A FEW MORE INCHES BY
MID-WEEK. WINDS WILL CONTINUE TO BE BREEZY INTO TUESDAY WITH GUSTS
20-25 MPH, MAKING BLOWING/DRIFTING SNOW AND LOWERED VISIBILITIES
LIKELY DURING THIS TIMEFRAME, ESPECAILLY GIVEN THE NATURE OF THE
SNOW (FINE, SMALL FLAKES). AN UPPER-LEVEL LOW LOOKS TO BRING A
PERIOD OF WIDESPREAD LIGHT SNOW WEDNESDAY NIGHT/THURSDAY WITH
PERHAPS SOME LINGERING LIGHT LAKE EFFECT SNOW SHOWERS THE LATER HALF
OF THE WEEK INTO THE WEEKEND. HOWEVER, OVERALL A DRYING TREND IS
EXPECTED AS HEIGHTS BUILD AT THE SURFACE AND ALOFT, WHICH SHOULD
SHUT OFF LAKE EFFECT SHOWERS.
DAYTIME HIGH TEMPERATURES LOOK TO BE IN THE TEENS WITH NEGATIVE
TEENS FOR WIND CHILL VALUES, ESPECIALLY HEADING INTO TUESDAY
MORNING. TEMPERATURES LOOK TO MODERATE BY MID-WEEK WITH VALUES
SLOWLY CREEPING BACK INTO THE MID TO UPPER 20S, AND POTENTIALLY EVEN
LOW 30S BY THE WEEKEND.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1128 PM EST SUN FEB 16 2025
MOSTLY MVFR TO VFR CONDITIONS EXPECTED TO CONTINUE THROUGH TODAY
UNDER PASSING LAKE CLOUDS AND SNOW SHOWERS. MAY SEE SOME PERIODS
OF IFR CONDITIONS UNDER ANY HEAVIER SNOW SHOWERS. TOTAL SNOW
ACCUMULATIONS AT THE TERMINALS SHOULD BE MOSTLY MINIMAL, MOSTLY
UNDER AN INCH. GUSTY WEST-NORTHWEST WINDS THROUGH THE PERIOD
WILL RESULT IN AT LEAST SOME MINOR BLOWING AND DRIFTING SNOW.
APX WATCHES/WARNINGS/ADVISORIES
MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
MIZ020>022-025>028-031>033-099.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ095.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR LHZ346-347.
SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR LMZ323-344>346.
SHORT TERM...JZ
LONG TERM...NSC
AVIATION...MSB
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