630
FXUS63 KMPX 222006
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
206 PM CST SUN DEC 22 2024
KEY MESSAGES
- CHANCE OF SNOW AND FREEZING DRIZZLE LATE TONIGHT AND EARLY
MONDAY ACROSS CENTRAL MN AND WESTERN WI. ANY ACCUMULATION
WOULD BE LIGHT, BUT TRAVEL CONDITIONS COULD VARY FROM AREA TO
AREA MONDAY MORNING.
- A WARMING TREND WILL OCCUR THIS WEEK WITH HIGHS IN THE LOW TO
MID 30S BY CHRISTMAS AND NEAR 40 POSSIBLE BY LATER IN THE
WEEK. RAIN CHANCES INCREASE LATE WEEK AND NEXT WEEKEND.
DISCUSSION
ISSUED AT 206 PM CST SUN DEC 22 2024
MORNING CLOUDS HAVE CLEARED AND MOST OF THE AREA HAS BEEN
ENJOYING CLEAR SKIES THROUGH EARLY AFTERNOON. HIGH CLOUDS ARE
RETURNING, HOWEVER, AHEAD OF A SHORTWAVE EVIDENT ON SATELLITE
IMAGERY OVER EASTERN MT AND CENTRAL ND. THIS SHORTWAVE WILL
DIG AND UNDERGO SOME STRENGTHENING TONIGHT AS IT PROPAGATES
EAST SOUTHEAST ACROSS THE SOUTHERN HALF OF MN. THIS WOULD
NORMALLY BE A STRONG SIGNAL FOR PRECIPITATION ACROSS THE AREA,
BUT A DRY WARM LAYER BETWEEN 850 AND 700 MB WILL EVAPORATE OR
SUBLIMATE HYDROMETEORS EFFICIENTLY. THE DGZ CENTERED BETWEEN 600
AND 500 MB DOES REMAIN SUFFICIENTLY SATURATED FOR MOST OF THE
EVENT. IF STRONGER BURSTS OF PRECIPITATION DEVELOP, THEN THE
DRY LAYER COULD TEMPORARILY BE OVERCOME. FORECAST SOUNDINGS
SHOW THIS SCENARIO QUITE WELL. AS OMEGA SPIKES WITHIN THE DGZ,
THE PROFILE IS QUICK TO SATURATE AND PRECIPITATION REACHES THE
SURFACE. AFTER THE OMEGA WEAKENS, THE DRY LAYER RETURNS. GIVEN
THE STRENGTH OF THE SHORTWAVE AND THE SATURATED DGZ, THESE
BURSTS APPEAR LIKELY TO FORM AT TIMES, BUT WILL REMAIN BRIEF AND
OF LOW COVERAGE ACROSS MN. IN WI, THE LIKELIHOOD OF FORMATION
IS HIGHER GIVEN THE FULLY MATURED SHORTWAVE BY THAT TIME AND AN
ABILITY TO KEEP MOST OF THE PROFILE SATURATED. THEREFORE,
HOURLY POPS ARE LOW, EXCEPT FOR AREAS CLOSER TO CENTRAL WI, BUT
LOOKING AT THE WHOLE PERIOD LATE TONIGHT AND EARLY MONDAY IT
SEEMS RELATIVELY LIKELY MOST AREAS WILL EXPERIENCE SOME LIGHT
PRECIPITATION AT SOME POINT HOWEVER BRIEF, WHETHER FROM FREEZING
DRIZZLE WITH SATURATION IN THE BOUNDARY LAYER OR FROM BURSTS OF
FREEZING RAIN OR SNOW AS OUTLINED BEFORE. REGARDLESS, ANY
ACCUMULATION OF SNOW OR ICE WOULD BE PRETTY LIGHT. TRAVEL
CONDITIONS MAY VARY FROM AREA TO AREA MONDAY MORNING, DEPENDING
ON HOW PREVALENT THE PRECIP IS IN THAT LOCATION.
A ZONAL BUT A WAVY SHORTWAVE-RICH PATTERN WILL DOMINATE THE REST
OF THE MONTH AND KEEP MILD AIR IN PLACE ACROSS MUCH OF NORTH
AMERICA. THE WEST COAST WILL BE SUBJECT BY A FIRE HOSE OF
MOISTURE FOR THE NEXT WEEK AND SOME OF THESE SYSTEMS WILL
SURVIVE THE TREK ACROSS THE ROCKIES TO EMERGE OVER THE PLAINS AS
WEAK, FAIRLY COMPACT SYSTEMS. GIVEN THE MAGNITUDE OF WARM AIR
THROUGHOUT THE ATMOSPHERE, PRECIPITATION WILL FALL AS LIQUID.
SOME FREEZING RAIN CAN'T BE RULED OUT AT NIGHT, BUT THAT WOULD
BE THE EXCEPTION WITH SURFACE TEMPS LIKELY REMAINING ABOVE
FREEZING. THE CURRENT SNOWPACK IS EXPECTED TO MAKE IT TO
CHRISTMAS, BUT PROBABLY NOT FAR BEYOND THAT.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1122 AM CST SUN DEC 22 2024
SKIES ARE CLEARING LATE THIS MORNING WITH ANOTHER DECK OF HIGH
CLOUDS EXPECTED TO ARRIVE DURING THE LATE AFTERNOON. VFR
CONDITIONS WILL CONTINUE UNTIL 06Z OR SO BEFORE MOST FALL INTO
MVFR WITH A WEAK DISTURBANCE MOVING THROUGH. SOME LIGHT SNOW
AND/OR FREEZING DRIZZLE IS POSSIBLE ACROSS CENTRAL MINNESOTA,
BUT OUR WISCONSIN SITES HAVE THE HIGHEST CHANCES OF SEEING
IMPACTS THROUGH MONDAY MORNING. CIGS/VIS WILL CONTINUE TO FALL
BY SUNRISE TOMORROW WITH IFR FOR ALL THROUGH THE END OF THE TAF
PERIOD. WINDS WILL GO LIGHT AND VARIABLE OVERNIGHT BEFORE
BECOMING NORTHWESTERLY AT 10KTS OR LESS.
KMSP...STILL DON'T HAVE THE CONFIDENCE TO GO MORE THAN A PROB30
FOR THE LIGHT SNOW/DRIZZLE REFERENCED ABOVE. IN ANY CASE, LOW
MVFR/IFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE MORNING
BEFORE CEILINGS BEGIN TO COME UP TO MVFR.
/OUTLOOK FOR KMSP/
TUE...MVFR/VFR. WIND S 5-10KTS.
WED...MVFR/VFR. WIND SE 5-10KTS.
THU...MVFR/VFR, CHC -RA/-SN. WIND SE 5-10KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...NONE.
WI...NONE.
DISCUSSION...BORGHOFF
AVIATION...DYE
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