455
FXUS63 KMPX 181736
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1236 PM CDT WED MAR 18 2026
KEY MESSAGES
- MUCH WARMER AIR BEGINS ARRIVING TODAY. STRATUS AND FOG ARE
POSSIBLE THROUGH EARLY FRIDAY AS THE MILDER AIR INTERACTS
WITH THE SNOWPACK. TEMPERATURES THROUGH SATURDAY WILL BE
DEPENDENT ON CLOUD COVER/FOG AND LINGERING SNOW DEPTH.
DISCUSSION
ISSUED AT 403 AM CDT WED MAR 18 2026
CLOUDS AND A FEW FLURRIES ARE LINGERING EAST OF THE MISSISSIPPI
RIVER EARLY THIS MORNING. THE EASTWARD PROGRESSION OF THE
CLEARING LINE HAS SLOWED DUE TO ITS NW-SE ORIENTATION AND THE
BANK'S MOVEMENT TOWARD THE ESE. WESTERN WI SHOULD BE CLOUDY MOST
OF THE MORNING, BUT EASTERN MN IS STILL EXPECTED TO CLEAR FOR A
TIME. HIGH CLOUDS ACROSS THE DAKOTAS WILL ARRIVE THIS
AFTERNOON. A WEAK SHORTWAVE IN THE NORTHWEST FLOW WILL PASS TO
THE NORTH THIS EVENING AND BRING A LOW CHANCE FOR RAIN NORTH OF
I-94.
THE MAIN CONCERN FOR THE NEXT COUPLE DAYS WILL BE THE POTENTIAL
FOR LOW CLOUDS AND FOG. THE SNOWPACK IS QUITE COLD CURRENTLY
FROM THE PAST COUPLE DAYS IN THE SINGLE DIGITS AND TEENS. AS
RIDGING FROM THE PLAINS WORKS EAST, MUCH WARMER AIR ALOFT
ARRIVES BEGINNING TODAY AND AN INVERSION AROUND 2 KFT WILL
DEVELOP. SURFACE DEW POINTS ALSO RISE WELL INTO THE 30S ATOP THE
COLD SNOWPACK. THIS SHOULD AT A MINIMUM RESULT IN SOME LOW
CLOUDS BELOW THE INVERSION, AND POSSIBLY WIDESPREAD DENSE FOG, AS
SURFACE TEMPERATURES COOL TO THE DEW POINT TONIGHT, BOTH OF
WHICH MAY REMAIN ABOVE FREEZING. FORECAST SOUNDINGS FROM THE NAM
AND GFS ARE SHOWING EXTENSIVE LOW CLOUDS AND FOG FOR THE NEXT
COUPLE DAYS, BUT THE RAP IS QUITE A BIT DRIER IN THE BOUNDARY
LAYER TONIGHT. MORE FOG WAS INTRODUCED TO THE WEATHER GRIDS
TONIGHT. SHOULD FOG INDEED DEVELOP, LIGHT WINDS IN THE BOUNDARY
LAYER AND THE INVERSION ALOFT WILL MAKE IT DIFFICULT TO BRING
IMPROVING CONDITIONS UNTIL PERHAPS THURSDAY AFTERNOON. EVEN
THEN, IT'S NOT LIKELY WE'LL LOSE THE LOW STRATUS ENTIRELY. IN
THIS SCENARIO, CURRENT FORECAST HIGH TEMPERATURES TOMORROW WOULD
BE TOO WARM. THE PROCESS MAY REPEAT AGAIN THURSDAY NIGHT INTO
FRIDAY IF THE SNOWPACK HASN'T ALREADY TAKEN A SIGNIFICANT HIT.
BY FRIDAY AFTERNOON THE SNOW WILL LIKELY BE GONE ACROSS
SOUTHERN AND WESTERN MN, AND STRONGER LOW LEVEL WINDS AND A
STRONGER LATE MARCH SUN ANGLE SHOULD BE ABLE TO MIX OUT ANY
MORNING STRATUS. HIGHS IN THE 60S ARE CURRENTLY EXPECTED THERE,
WITH 40S AND 50S LINGERING FARTHER NORTHEAST WHERE THE DEEPER
SNOW MAY STILL BE HANGING ON.
A THERMAL RIDGE MOVES IN SATURDAY AHEAD OF A COLD FRONT. BY
THIS POINT, A COUPLE DAYS OF FOG AND TEMPERATURES CONTINUOUSLY
ABOVE FREEZING SHOULD HAVE TAKEN CARE OF THE REST OF THE SNOW.
925 MB TEMPS OF +18 TO +20C SIGNAL HIGHS AS WARM AS THE MID TO
UPPER 70S ACROSS SOUTHERN MN. THERE ARE STILL TIMING QUESTIONS
WITH THE COLD FRONT, BUT THE ECMWF AND AIFS HAVE SLOWED DOWN ITS
ARRIVAL FROM YESTERDAY, NOW BRINGING IT IN SATURDAY EVENING.
THEREFORE THE TEMP FORECAST HAS INCREASED, BUT IS STILL A
LITTLE MODEST WITH A LOT OF SPREAD REMAINING. COOLER TEMPERATURES
RETURN BEHIND THE FRONT, BUT REMAINING NEAR NORMAL INTO EARLY
NEXT WEEK.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1228 PM CDT WED MAR 18 2026
MVFR STRATUS CONTINUES TO CLEAR VERY SLOWLY FROM NORTHWEST TO
SOUTHEAST ACROSS WESTERN WISCONSIN. GIVEN THE ORIENTATION OF
THE CLEARING LINE, IT MAY BE ANOTHER FEW HOURS BEFORE FOR KRNH
AND KEAU. MID/HIGH CLOUDS WILL INCREASE THIS AFTERNOON. LOW
CLOUDS AND FOG APPEAR LIKELY TO DEVELOP AREA WIDE TONIGHT, BUT
OVERALL CONFIDENCE ISN'T PARTICULARLY HIGH GIVEN THE INCREASED
MID LEVEL CLOUD COVER. I HAVE ADDED & INCREASED THE LIKELIHOOD
OF BR/FG IN THIS SET OF TAFS. WHILE MID-LEVEL CLOUD COVER COULD
SLOW THE PROCESS, LIGHT & VARIABLE WINDS COMBINED WITH SNOW MELT
MOISTURE TRAPPED BENEATH THE INVERSION SHOULD SUPPORT FOG. FOG
WILL BE SLOW TO BURN OFF, BUT SHOULD IMPROVE THURSDAY AM. LOW
STRATUS LIKELY REMAINS ON THURSDAY GIVEN THE FEEDBACK LOOP WITH
SNOWMELT & LIGHT WINDS.
KMSP...IFR (OR WORSE) CONDITIONS RETURN OVERNIGHT WITH
FOG/MIST. CONFIDENCE ISN'T PARTICULARLY HIGH ON THE TIMING OF
WHEN VSBY IMPROVES TOMORROW MORNING, BUT CURRENT GUIDANCE
SUPPORTS BY LATE MORNING.
/OUTLOOK FOR KMSP/
FRI...VFR. WIND SW TO NW 5-10KTS.
SAT...VFR. WIND SW 10-15KTS.
SUN...VFR. WIND N 10-15KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...NONE.
WI...NONE.
DISCUSSION...BORGHOFF
AVIATION...BPH
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