794
FXUS63 KDLH 212341
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
541 PM CST SAT DEC 21 2024
KEY MESSAGES
- NORTH SHORE LAKE EFFECT SNOW EXPECTED TO CONTINUE THROUGH
SUNDAY MORNING WITH LIGHT ACCUMULATIONS UP TO A COUPLE
INCHES.
- A QUICK MOVING SYSTEM BRINGS ANOTHER CHANCE FOR SNOW LATE
SUNDAY INTO MONDAY MORNING. LIGHT ACCUMULATIONS EXPECTED WITH
LOCALIZED HIGHER AMOUNTS POSSIBLE.
- WARMING TREND THROUGH THE WEEK, WITH A CHANCE FOR A SYSTEM TO
BRING MIXED PRECIPITATION TOWARDS THE END.
DISCUSSION
ISSUED AT 237 PM CST SAT DEC 21 2024
THROUGH THE WEEKEND: A WEAK IMPULSE CONTINUES TO PRODUCE RADAR
RETURNS OVER NORTH-CENTRAL MN MOVING EAST EARLY THIS AFTERNOON, BUT
THANKS TO DRY AIR NEAR THE SURFACE, LITTLE TO NONE OF THIS HAS
ACTUALLY MADE IT TO THE GROUND. A LAKE-INDUCED MESO-LOW MOVED UP THE
NORTH SHORE TODAY, BUT HAS STEADILY LOST ITS STRUCTURE THIS
AFTERNOON, BECOMING MORE PURE LAKE EFFECT SNOW AS IT PROPAGATES
ACROSS PORTIONS OF COASTAL LAKE AND COOK COUNTY. AS THE SYNOPTIC
FEATURE PUSHES EAST, LAKE EFFECT MOISTURE SHOULD ALLOW FOR A
BLOSSOMING OF BETTER COVERAGE LAKE EFFECT SNOW ALONG THE NORTH SHORE
OVERNIGHT. HALF INCH UP TO NEAR 3 INCHES OF ACCUMULATIONS COULD BE
POSSIBLE, ESPECIALLY ALONG THE HIGHER TERRAIN IN COOK COUNTY.
SUNDAY-MONDAY SYSTEM: A STOUT LITTLE UPPER LEVEL SHORTWAVE IS
PROGGED TO MOVE OVER MINNESOTA AND WISCONSIN FAIRLY ZONALLY LATE
SUNDAY INTO MONDAY MORNING, BRINGING SOME LIGHT SNOW ACCUMULATIONS.
DETERMINISTIC MODEL DATA POINTS TO THIS SYSTEM CHECKING A LOT OF
BOXES FOR SOME ENHANCED BANDED SNOWFALL, WITH A GOOD HEIGHT
FALL/RISE COUPLET, SUFFICIENT DENDRITIC GROWTH ZONE MOISTURE AND
LIFT, AND SOME WEAK NEAR-SURFACE FRONTOGENESIS. MODELS CONTINUE TO
PICK UP ON THIS ZIPPY LOCALIZED HEAVY BAND HAVING THE POTENTIAL TO
OVERPRODUCE AND GIVE A SMALL AREA 2-4" OF SNOW. HOWEVER, AS A
TESTIMONIAL TO THE REMAINING UNCERTAINTY FOR THIS SYSTEM, MODEL-TO-
MODEL AND RUN-TO-RUN CONSISTENCY CONTINUES TO BE AN ISSUE. DEPENDING
ON YOUR DESIRED MODEL RUN OR ENSEMBLE MEMBER, THIS NARROW BAND COULD
BEGIN SET UP ANYWHERE FROM JUST NORTH OF THE TWIN PORTS TO
ROCHESTER. LATEST PROBABILITIES PUT THE GREATEST CHANCE FOR 1" OR
MORE SOMEWHERE IN THE NORTHWEST TO WEST-CENTRAL WISCONSIN AREA, BUT
WE'VE KEPT POPS FAIRLY BROAD AND NOT TOO HIGH DUE TO LINGERING LOW
CONFIDENCE. TWO OTHER CONSIDERATIONS FOR THIS SYSTEM: 1) WITH
NORTHEAST WINDS OVER LAKE SUPERIOR, SOME LAKE ENHANCEMENT COULD BE
POSSIBLE FOR COASTAL AREAS AND 2) MODEL SOUNDINGS SUGGEST THERE MAY
BE AREAS OF INSUFFICIENT DGZ MOISTURE, WHICH COULD LEAD TO SOME
PATCHY FREEZING DRIZZLE AT TIMES.
NEXT WEEK: MONDAY'S SYSTEM SPINS OUT AS QUICKLY AS IT ARRIVES,
LEAVING US WITH BUILDING HIGH PRESSURE AND FAIRLY QUIET WEATHER
THROUGH MIDWEEK. THIS WILL LEAD TO STEADILY WARMING TEMPERATURES AND
PROBABLY A FAIR AMOUNT OF CLOUDINESS IN A WAA REGIME. WARMING
CONTINUES INTO THE END OF THE WEEK, WITH WIDESPREAD HIGH TEMPERATURES
RISING OVER FREEZING BY THE 25TH OR 26TH. IF YOU'RE A SNOW
ENTHUSIAST, YOU MAY WANT TO LOOK AWAY BEFORE READING THIS NEXT PART.
THERE CONTINUES TO BE GROWING ENSEMBLE AGREEMENT FOR ONE OR MORE
SYSTEMS TO TRAVERSE THE UPPER MIDWEST LATE NEXT WEEK INTO THE
WEEKEND, WHICH BASED ON TEMPERATURES WOULD LIKELY BE A MESSY MIXED
PRECIPITATION TO ALL RAIN EVENT. TOO SOON TO EXACTLY PINPOINT THIS
OR TALK ABOUT POSSIBLE RAINFALL AMOUNTS. LATEST 2-3 WEEK GUIDANCE
SUGGESTS THAT HOPEFULLY INTO THE NEW YEAR WE'LL BE ABLE TO START
BRINGING OUR TEMPERATURES BACK TO MORE WINTER-LIKE LEVELS AND SEE
PREDOMINANT SNOW RETURN.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 541 PM CST SAT DEC 21 2024
VFR CONDITIONS WERE OCCURRING FOR MOST EARLY THIS EVENING WITH
SOME FLURRIES OCCURRING OVER PORTIONS OF THE NORTHLAND,
INCLUDING SOME LIGHT SNOW/FLURRIES ALONG THE NORTH SHORE DUE TO
LAKE PROCESSES. CEILINGS WILL LOWER TONIGHT TO MVFR OR IFR FOR
MOST LOCATIONS AND THOSE CEILINGS WILL THEN CONTINUE THROUGH
SUNDAY. A WEAK SHORTWAVE WILL MOVE THROUGH THE NORTHLAND LATER
TONIGHT INTO SUNDAY MORNING AND MAY CAUSE SOME FLURRIES IN
NORTHERN MINNESOTA, WITH LIGHT LAKE EFFECT ALONG THE NORTH SHORE
ALSO CONTINUING INTO SUNDAY MORNING.
A STRONGER SHORTWAVE AND AN AREA OF LOW PRESSURE WILL LEAD TO SOME
ADDITIONAL CHANCES FOR PRECIPITATION SUNDAY NIGHT INTO MONDAY
MORNING. THERE REMAINS CONSIDERABLE UNCERTAINTY ON WHERE A
NARROWER AREA OF ENHANCED PRECIPITATION WILL END UP AND
CONFIDENCE IS LOW ON WHERE THAT WILL BE RIGHT NOW.
PRECIPITATION TYPE SHOULD BE MOSTLY LIGHT SNOW BUT A BIT OF
FREEZING DRIZZLE CAN'T BE DISCOUNTED EITHER.
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
ISSUED AT 237 PM CST SAT DEC 21 2024
WINDS BECOME SOUTHERLY TODAY, INCREASING IN STRENGTH INTO SUNDAY
MORNING WITH A TIGHTENING PRESSURE GRADIENT. WIND GUSTS OF 20 TO 25
KNOTS ARE POSSIBLE EARLY THROUGH MID MORNING SUNDAY, WITH INCREASING
WAVE HEIGHTS OF 3 TO 6 FEET ALONG PORTIONS OF THE NORTH SHORE. A
SMALL CRAFT ADVISORY HAS BEEN ISSUED. THROUGH THE DAY AND EVENING
SUNDAY, WINDS SHOULD WEAKEN, EVENTUALLY BECOMING NORTHERLY INTO
MONDAY AROUND 10 TO 15 KNOTS.
FOR THE OPEN WATER DISCUSSION, REFER TO THE NWS MARQUETTE AREA
FORECAST DISCUSSION AT WEATHER.GOV/MQT.
DLH WATCHES/WARNINGS/ADVISORIES
MN...NONE.
WI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM CST SUNDAY FOR LSZ140-
141.
SMALL CRAFT ADVISORY FROM 4 AM TO 10 AM CST SUNDAY FOR LSZ147-
148-150.
DISCUSSION...LEVENS
AVIATION...MELDE
MARINE...LEVENS
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