353
FXUS63 KMPX 312034
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
334 PM CDT MON MAR 31 2025
KEY MESSAGES
- WIDESPREAD PRECIPITATION SPREADS NORTHEAST INTO MINNESOTA AND
WISCONSIN EARLY TUESDAY, WITH HEAVY SNOW AND RAIN EXPECTED.
- A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR PORTIONS OF
WEST-CENTRAL MINNESOTA, WHERE SNOW WILL START TUESDAY MORNING.
A WINTER STORM WATCH STAYS IN PLACE FOR CENTRAL MINNESOTA,
WHERE THE GREATEST THREAT FOR HEAVY SNOW REMAINS.
- AN EXTENDED PERIOD OF QUIETER WEATHER SETS IN FOR THE END OF
THIS WEEK INTO NEXT WEEK, WITH TEMPERATURES RUNNING SLIGHTLY
BELOW NORMAL.
DISCUSSION
ISSUED AT 327 PM CDT MON MAR 31 2025
SKIES HAVE CLEARED THIS AFTERNOON AND THE LIGHT SNOW & ICE
ACCUMULATIONS FROM OUR WEEKEND SYSTEM HAVE BEGUN TO QUICKLY
RECEDE. ALL THIS DOES IS SET UP A CLEAN SLATE FOR OUR NEXT
SYSTEM WHICH IS FORECAST TO ARRIVE TOMORROW MORNING IN WESTERN
MINNESOTA.
SURFACE CYCLOGENESIS WILL OCCUR TONIGHT OFF THE LEE OF THE
ROCKIES, AND A BROAD AREA OF STRONG ISENTROPIC ASCENT WILL
RESULT IN A QUICK ENE PUSH OF PRECIPITATION TUESDAY MORNING. PER
SPRING STORM STANDARDS FOR US, PRECIP TYPE WILL BE A BIG
TALKING POINT IN THIS EVENT AGAIN. ALTHOUGH THIS TIME AROUND IT
WILL MAINLY BE A DIFFERENCE BETWEEN RAIN VERSUS SNOW,
POTENTIALLY RAIN VERSUS HEAVY SNOW AT TIMES. FORECAST SOUNDINGS
SHOW AN INITIALLY COLD AIR MASS IN PLACE, WITH WEAK LOW LEVEL
WAA GRADUALLY LIFTING NEAR SURFACE TEMPS BY A FEW DEGREES EAST
OF THE SURFACE LOW. GIVEN SURFACE TEMPERATURES WILL BE RIGHT
AROUND THE 32F MARK, THE DEPTH AND EXTENT OF A NEAR SURFACE WARM
LAYER COULD MEAN THE DIFFERENCE BETWEEN HEAVY SNOW AND A
DOWNPOUR AS THE MAIN BAND OF SNOW SPREADS NORTHEAST. THIS IS
ILLUSTRATED WELL BY MANY OF THE CAMS' 1 HOUR SNOWFALL FORECAST,
WHERE A VERY SHARP GRADIENT BETWEEN 1"+/HOUR RATES PRACTICALLY
BORDER 0" SNOWFALL RATES ALONG THE SOUTHERN EDGE OF THE SNOW
BAND. ALTHOUGH SOME SLEET, AND TO A LESSER EXTENT FREEZING RAIN,
COULD MIX IN DURING THIS TRANSITION PHASE, IT IS MORE LIKELY
THAT A SWITCH TO ALL RAIN WILL OCCUR. THIS WOULD MAKE AN ALREADY
WET, HEAVY SNOW (SLRS ~8-10:1) EVEN MORE CONCRETE-ESQUE.
AS THE LOW SLIDES NE, A DRY SLOT WILL LIKELY BEGIN TO LIMIT
PRECIPITATION HEADING INTO WEDNESDAY. SOME OF THE HI-RES DATA
DOES HINT AT WEAK INSTABILITY DEVELOPING ACROSS SOUTHERN
MINNESOTA INTO WEDNESDAY MORNING. THIS WOULD LIKELY BE MORE OF A
GUSTY SHOWER SETUP WITH AN OCCASIONAL RUMBLE OF THUNDER. WRAP
AROUND FLURRIES/SPRINKLES ARE POSSIBLE FOR THE REST OF THE DAY,
MAINLY OVER CENTRAL MINNESOTA.
WHAT HAS CHANGED IN THE LAST 12 HOURS? ACROSS THE BOARD,
ENSEMBLE GUIDANCE HAS STARTED TRENDING TOWARDS A MORE SOUTHERN
LOW TRACK AND WEAKER LOW CENTRAL PRESSURE. THE MAIN IMPACT THIS
HAS ON THE FORECAST IS A DROP IN QPF BY ~0.1-0.2" AND A SLIGHT
NORTHERN PUSH OF THE EXPECTED RAIN/SNOW LINE (STRONGER INFLUX OF
MID LEVEL WARM AIR). THE 12Z HI-RES SUITE HIGHLIGHTS THIS
SOUTHERN TREND AS WELL, WITH THE HEAVIEST SNOWFALL RATES
ARRIVING TO CENTRAL MN AND WESTERN WI BETWEEN 2-7PM. THIS WOULD
CERTAINLY LEAD TO TRAVEL IMPACTS FOR TUESDAY'S EVENING COMMUTE.
GIVEN THE RECENT SHIFTS, THERE IS STILL A NOTE OF UNCERTAINTY
REGARDING THE EXTENT AND PLACEMENT OF THE HIGHEST SNOWFALL
AMOUNTS.
A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR PORTIONS
OF WEST- CENTRAL MINNESOTA WHERE WE HAVE HIGH CONFIDENCE OF SUB-
WARNING LEVEL SNOW (LESS THAN 6 INCHES). THE WINTER STORM WATCH
REMAINS IN PLACE FOR PLACES TO THE NORTHEAST OF THE ADVISORY,
WHERE WARNING LEVEL SNOW IS STILL POSSIBLE. WRIGHT, SHERBURNE,
AND KANABEC COUNTIES ARE LEANING MORE TOWARDS ADVISORY LEVEL
SNOW, BUT A LATER ONSET TIME GIVES A LITTLE MORE WIGGLE ROOM TO
GAIN HIGHER CONFIDENCE. AN EXPANSION OF THE ADVISORY IS ALSO
LIKELY INTO PORTIONS OF WESTERN WISCONSIN WHERE A FEW INCHES OF
SNOW ARE EXPECTED. THE TWIN CITIES METRO REMAINS RIGHT ON THE
LINE, WITH MORE RAIN BEING FAVORED THAN SNOW THROUGHOUT THE
COURSE OF THE EVENT. THAT SAID, A COUPLE HOURS OF HEAVY SNOWFALL
COULD LEAD TO TRAVEL IMPACTS DURING THE AFTERNOON. AN EXPANSION
OF THE ADVISORY IS MOST LIKELY FOR THE NORTHERN COUNTIES
(WRIGHT AND ANOKA), BUT ANY SOUTHERN SHIFT IN TOTALS COULD
INCLUDE MORE OF THE METRO.
A WORD OF CAUTION FOR THIS PARTICULAR EVENT. PROCEED WITH CARE
WHEN LOOKING AT SNOWFALL MAPS WITH 10:1 RATIOS (AND EVEN
KUCHERA). A COMBINATION OF WET SLRS, MELTING SNOW, COMPACTION,
AND GUSTY WINDS WILL ALL EAT AWAY AT THE ACCUMULATIONS. SOME
AREAS MAY RECEIVE DOUBLE DIGIT SNOWFALL AMOUNTS, BUT IT LIKELY
WILL BE DIFFICULT TO SEE THE SNOW DEPTH REACH THAT POINT AFTER
ALL IS SAID AND DONE. OUR LATEST FORECAST DROPS TOTALS A BIT,
BUT LEAVES THE HIGHEST AMOUNTS ACROSS CENTRAL MINNESOTA.
REGARDING TOTAL PRECIPITATION, THIS SYSTEM WILL BRING ANOTHER
0.5 TO 1.5" OF LIQUID TO THE REGION, WITH HIGHER AMOUNTS FALLING
ACROSS WESTERN AND CENTRAL MINNESOTA (WHO GENERALLY RECEIVED
LESSER AMOUNTS OVER THE WEEKEND).
THURSDAY THROUGH MONDAY... A QUIETER STRETCH OF WEATHER IS ON
DECK AS THE LOW EJECTS NORTHEAST AND A HIGH PRESSURE SITUATES
OVER THE UPPER MISSISSIPPI RIVER VALLEY. A NEGATIVELY TILTED,
ELONGATED TROUGH WILL SPAWN A STRONG LOW THAT WILL RESULT IN
WIDESPREAD PRECIPITATION AHEAD AND JUST NORTHWEST OF IT. THIS
REX BLOCK SETUP WILL PUT IN THE WORK TO KEEP US ON THE DRY,
NORTHERN SIDE. PREDOMINANT NORTHWEST FLOW SETTLES IN BY NEXT
WEEK, KEEPING TEMPERATURES JUST AT OR SLIGHTLY BELOW NORMAL FOR
EARLY APRIL (WHICH IS IN THE LOW 50S FOR HIGHS AND LOW 30S FOR
LOWS). BY THE END OF THE MONTH, AVERAGE HIGHS WILL BE IN THE MID
60S AND AVERAGE LOWS IN THE MID 40S.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1132 AM CDT MON MAR 31 2025
QUIET WEATHER TODAY WITH A LOW VFR STRATUS DECK EXITING TO OUR
SOUTH/EAST OVERNIGHT. LOOKING AHEAD TO THE OVERNIGHT PERIOD,
WE'LL SEE WINDS SWITCH FROM THE NORTHWEST OVER TO THE SOUTHEAST.
A PERIOD OF LIGHT & VARIABLE WINDS WILL BE LIKELY AND IS
REFLECTED INTO THE TAFS. I HAVE INTRODUCED -RASN/-SN FOR SEVERAL
SITES BY THE END OF THIS TAF PERIOD. THE HEAVIEST PRECIPITATION
FALLS AFTER 18Z TUESDAY AND I'VE UTILIZED A PROB30 TO BEGIN TO
INTRODUCE LOW MVFR/IFR VSBY/CIGS. WINDS WILL RAMP UP OUT OF THE
SE WITH GUSTS UP TO 25KTS POSSIBLE.
KMSP...I'VE TRANSITIONED THE PROB30 TO A PREVAILING -RASN GROUP.
WE'LL SEE HEAVIER RATES PICK UP AFTER 18Z BUT THERE IS STILL
UNCERTAINTY WITH WHAT P-TYPE WE'LL BE DEALING WITH GIVEN THE
BORDERLINE CONDITIONS FOR SNOW. WE'LL HOPE TO INCREASE
CONFIDENCE WITH OUR P-TYPES FOR THE 00Z SET OF TAFS. ALSO OPTED
TO INCLUDE A LLWS GROUP FROM 21Z TO 00Z WEDNESDAY GIVEN THE
STRENGTHENING LOW LEVEL FLOW AS THE LOW PRESSURE APPROACHES.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR, -RASN. WIND E 15-20G30KTS BCMG SW 20-25G35KTS.
THU...CHC MVFR CIGS. WIND NW 10-15KTS.
FRI...VFR. WIND VRB 3-5KTS BCMG W 5-10KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
EVENING FOR DOUGLAS-POPE.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR BENTON-ISANTI-KANABEC-MILLE LACS-MORRISON-
SHERBURNE-STEARNS-TODD-WRIGHT.
WINTER WEATHER ADVISORY FROM 7 AM TUESDAY TO 7 PM CDT
WEDNESDAY FOR CHIPPEWA-KANDIYOHI-LAC QUI PARLE-MCLEOD-
MEEKER-RENVILLE-STEVENS-SWIFT-YELLOW MEDICINE.
WI...NONE.
DISCUSSION...BED
AVIATION...BPH
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