338
FXUS63 KMPX 181802
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1202 PM CST MON NOV 18 2024
KEY MESSAGES
- WIDESPREAD SOAKING RAINFALL THIS AFTERNOON INTO TUESDAY
MORNING. AN INCH OR SO OF RAIN APPEARS LIKELY AT MOST
LOCATIONS.
- COLDER AIR ARRIVES MID-WEEK. SOME SNOW ACCUMULATION POSSIBLE
ACROSS WESTERN MINNESOTA TUESDAY NIGHT THROUGH WEDNESDAY.
- TEMPERATURES WILL BE MUCH COLDER BY THE END OF THE WORK WEEK,
WITH HIGHS IN THE 30S AND LOWS IN AT LEAST THE 20S.
DISCUSSION
ISSUED AT 259 AM CST MON NOV 18 2024
CLEAR SKIES AND LIGHT WINDS TONIGHT HAVE ALLOWED TEMPERATURES TO
DROP INTO THE LOW TO MID 30S. EVEN SOME PESKY FOG HAS DEVELOPED
AT EAU AND HAS BEEN FLUCTUATING BACK AND FORTH AT THE ASOS.
HIGHS TODAY WILL WARM INTO THE LOW TO MID 50S BUT CLOUD COVER
WILL QUICKLY INCREASE FROM SOUTH TO NORTH AS OUR NEXT LOW
PRESSURE SYSTEM APPROACHES. ADDITIONALLY, AS THE SURFACE
PRESSURE GRADIENT TIGHTENS, EASTERLY WINDS WILL ALSO INCREASE,
ESPECIALLY THIS AFTERNOON AND INTO THIS EVENING WHEN GUSTS COULD
REACH 35 MPH. CAMS CONTINUE TO SHOW THE NORTHERN EDGE OF THE
LOW'S LARGE PRECIPITATION SHIELD REACHING THE MN/IA BORDER BY
1-2 PM THIS AFTERNOON. FROM THEN, RAIN WILL CONTINUE TO SPREAD
NORTH COVERING THE ENTIRE CWA BY 8 PM AND LIKELY LASTING FOR THE
ENTIRE NIGHT. ONLY WHEN THE SURFACE LOW FINALLY PASSES NORTH
OVER US AND THE DRY SLOT STARTS TO WRAP IN ON THE LOW'S SOUTH
SIDE WILL PRECIPITATION BEGIN TO SHUT OFF FROM SOUTH TO NORTH
DURING TUESDAY. RAINFALL AMOUNTS WILL GENERALLY BE 1-1.5" CWA-
WIDE, ACCORDING TO GUIDANCE. LOCALLY HIGHER AMOUNTS COULD OCCUR
ACROSS SOUTHERN MN WHERE A MEAGER AMOUNT OF CONVECTIVE
INSTABILITY IS FORECAST. MOST OF THE CWA SHOULD DRY OUT AS DRY
AIR ON THE BACKSIDE ADVECTS COUNTER-CLOCKWISE, EXCEPT FOR
PORTIONS OF CENTRAL MN (AXN, STC, BRD, ETC.). HERE, FORECAST
SOUNDINGS HANG ON TO GREATER LOW-LEVEL SATURATION, SO DRIZZLE
AND REDUCED VISIBILITIES COULD BECOME AN ISSUE TUESDAY MORNING
INTO THE AFTERNOON. WINDS WILL ALSO TURN TO WESTERLY DURING
TUESDAY AND REMAIN STRONG AFTER THE SURFACE LOW PASSES OVERHEAD.
THE LOW WILL OCCLUDE AND CONTINUE NORTHWARD BEFORE STALLING OUT
OVER EASTERN MANITOBA/WESTERN ONTARIO TUESDAY NIGHT.
WHILE THE RAIN ASSOCIATED WITH THE ARCHING COLD FRONT/WARM
SECTOR WILL BE LOCATED WELL TO OUR NORTH BY TUESDAY EVENING,
LIGHT WRAP- AROUND PRECIP ON THE WEST SIDE OF THE LOW WILL BE
MOVING SOUTHWARD INTO WESTERN MN. AT THE SAME TIME, MUCH COLDER
AIR ASSOCIATED WITH A STRONG UPPER-LEVEL TROUGH WILL BE ARRIVING
FROM THE WEST. THE PRECIP IN WESTERN MN WILL ORIGINALLY BE
RAIN, BUT AS THE COLUMN COOLS FROM CAA A CHANGE TO A RAIN-SNOW
MIX TO EVENTUAL SNOW IS EXPECTED. THE TRANSITION TO SNOW SHOULD
BE COMPLETE BY WEDNESDAY MORNING WITH LIGHT SNOW SPREADING OVER
THE REMAINDER OF OUR CWA FROM WEST TO EAST DURING WEDNESDAY
MORNING. WE WILL LIKELY SEE SNOW SHOWERS INTO WEDNESDAY NIGHT,
BUT LITTLE ACCUMULATION IS EXPECTED OWING TO THE FORECAST LOW
SNOWFALL RATES AND WARM GROUND TEMPERATURES. HOWEVER, A COUPLE
OF INCHES MAY BE POSSIBLE IN WESTERN MN WHERE BETTER LIFT AND
SLIGHTLY BETTER SNOWFALL RATES ARE FORECAST. SOME LIGHT FREEZING
DRIZZLE IS ALSO POSSIBLE, MAINLY IN CENTRAL MN, WHERE FORECAST
SOUNDINGS ARE HINTING AT SUB-FREEZING LOW-LEVEL SATURATION THAT
IS BELOW THE DGZ. TEMPERATURES WILL PLUMMET WITH WEDNESDAY'S
HIGHS ONLY EXPECTED IN THE 30S. COMBINED WITH THE STILL STRONG
WESTERLY WINDS AND SNOW SHOWERS, WEDNESDAY LOOKS LIKE AN
UNPLEASANT DAY TO BE OUTSIDE.
GUIDANCE SUGGESTS THE LIGHT SNOW WILL DISSIPATE AND MOVE EAST
EARLY THURSDAY MORNING. THE REMAINDER OF THE WEEK LOOKS COLD
AND DRIER WITH POTENTIALLY LOTS OF CLOUD COVER. COLD AIR IS
FORECAST TO KEEP FUNNELING INTO THE NORTHERN PLAINS THROUGH THE
END OF THE WEEK AS NORTHWESTERLY FLOW SETS UP DOWNSTREAM OF A
RIDGE OVER THE ROCKIES. OUR FIRST REAL TASTE OF WINTER STARTS
THURSDAY NIGHT AS LOWS WILL DROP TO NEAR 20 IN WESTERN MN WITH
20S TO NEAR 30 ELSEWHERE. TEMPERATURES ONLY GET WORSE FRIDAY AND
SATURDAY NIGHT WHEN MID TO UPPER TEENS ARE POSSIBLE IN WESTERN
MN. NOT MUCH WARMING WILL OCCUR DURING THE DAY EITHER AS HIGHS
IN THE MID 20S TO MID 30S ARE FORECAST. A SLIGHT REBOUND IN
TEMPERATURES IS POSSIBLE EARLY NEXT WEEK AS LONG-RANGE MODELS
SHOW THE NORTHWEST FLOW BRIEFLY SUBSIDING. HOWEVER, THESE SAME
MODELS ALSO DRAG THE POOL OF REALLY COLD AIR THAT WAS OVER
WESTERN CANADA OVER TO THE NORTHERN HIGH PLAINS AND CANADIAN
PRAIRIES. THE NORTHERLY JETSTREAM ALSO GETS DISPLACED MORE TO
THE SOUTH ACROSS THE CONUS DURING NEXT WEEK. THE COLDER AIR WILL
THEN BE MORE EASILY ACCESSIBLE TO ANY SHORTWAVES THAT FORM
WITHIN THE FLOW. THUS, WE WOULD HAVE BETTER CHANCES AT WINTRY
TEMPERATURES AND PRECIPITATION TOWARDS THE END OF NOVEMBER AND
BEGINNING OF DECEMBER.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1145 AM CST MON NOV 18 2024
IFR STRATUS HAS ALREADY MOVED INTO SOUTHERN MINNESOTA OUT AHEAD
OF THE APPROACHING SHIELD OF RAIN, SO THE MAIN UPDATE THIS
PERIOD HAS BEEN TO SPEED UP THE ARRIVAL OF MVFR/CEILINGS BY A
FEW HOURS THIS AFTERNOON. 2-3 HOURS AFTER THE LOWER CEILINGS
ARRIVE, THE FORECAST STILL REMAINS ON TRACK FOR SEVERAL HOURS
OF STEADY RAIN THIS EVENING & OVERNIGHT. CEILINGS WILL QUICKLY
DROP TO IFR AS THE RAIN BEGINS, WITH VISIBILITY HOVERING BETWEEN
2-4SM THROUGH THE NIGHT. EASTERLY WINDS WILL ALSO INCREASE AS
THE WIND BEGINS, WITH LLWS UP TO 50 KTS DURING THE PERIOD OF
HEAVIEST RAIN THIS EVENING & TONIGHT. THE MAIN BAND OF RAIN WILL
MOVE NORTH OF THE AREA OVERNIGHT, MAINLY BETWEEN MIDNIGHT TO 3
AM. SOME BREAKS IN THE RAIN ARE LIKELY AFTER THIS TIME, WITH
ISOLATED TO SCATTERED SHOWERS EXPECTED TO LINGER INTO THE
MORNING. THE RAIN TOTALLY EXITS THE AREA BY MID TO LATE
MORNING, WITH CEILINGS LIKELY IMPROVING TO MVFR & POSSIBLY VFR
IF BREAKS IN THE CLOUD COVER BECOME WIDESPREAD.
SOUTHEAST WINDS AROUND 10 KTS WILL INCREASE THIS AFTERNOON,
BECOMING EASTERLY AS THE RAIN BEGINS. WINDS WILL SHARPLY
INCREASE WITH THE RAIN, WITH GUSTS AROUND 30 KTS EXPECTED THIS
EVENING& TONIGHT. WINDS WILL BECOME VARIABLE AND WEAKEN
SOMEWHAT OVERNIGHT AS THE SURFACE LOW MOVES THROUGH THE AREA,
WITH THE DIRECTION GENERALLY BECOMING SOUTHEASTERLY OVERNIGHT &
WESTERLY TO SOUTHWESTERLY TOMORROW MORNING. WIND GUSTS AROUND
30 KTS RETURN WITH THE WESTERLY WIND SHIFT TOMORROW MORNING.
KMSP...LOWER CEILINGS ARE ADVANCING OUT AHEAD OF THE APPROACHING
RAIN, SO EXPECT MVFR CEILINGS TO REACH THE TERMINAL AS EARLY AS
2 PM. THE RAIN STILL APPEARS ON TRACK TO ARRIVE BETWEEN 4-5 PM,
WITH CEILINGS DROPPING TO IFR AND VISIBILITY HOVERING AROUND
IFR/MVFR LEVELS. SOUTHEAST WINDS BECOME MORE EASTERLY AS THE
RAIN ARRIVES WITH GUSTS AROUND 30 KTS EXPECTED DURING THE RAIN.
THE MAIN BAND OF RAIN WILL EXIT THE AREA AROUND 2-3 AM, WITH
ISOLATED TO SCATTERED SHOWERS LINGERING INTO THE MORNING. WINDS
QUICKLY SWITCH FROM EASTERLY, TO SOUTHERLY, TO WESTERLY BETWEEN
6-9 AM TOMORROW MORNING. WINDS WILL SLACKEN DURING THIS WIND
SHIFT, BUT GUSTS AROUND 30 KTS RETURN AS THE WIND BECOMES
WESTERLY.
/OUTLOOK FOR KMSP/
WED...MVFR. CHANCE -SHSN/IFR. WIND W 15-25G25-35KTS.
THU...MVFR CIGS LIKELY. WIND NW 15-20G25-30KTS.
FRI...VFR. WIND NW 10-15KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...NONE.
WI...NONE.
DISCUSSION...CTG
AVIATION...ETA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page