579
FXUS63 KMPX 281927
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
227 PM CDT TUE APR 28 2026
KEY MESSAGES
- PATCHY FROST TONIGHT, HOWEVER CLOUD COVER AND MARGINAL
TEMPERATURES SHOULD KEEP IT FROM BECOMING WIDESPREAD.
- QUIET WEATHER CONTINUES THIS WEEK, WITH A CHANCE FOR ISOLATED
SPRINKLES TOMORROW AFTERNOON.
DISCUSSION
ISSUED AT 226 PM CDT TUE APR 28 2026
A COOL BUT OTHERWISE PLEASANT AFTERNOON UNFOLDS BEFORE US AS GOES
SATELLITE IMAGERY HIGHLIGHTS AN INCREASING FIELD OF CLOUD COVER
EXPANDING TO OUR SOUTHWEST WITH MOSTLY CLOUDY SKIES EXPECTED BY THIS
EVENING FOR MOST OF SOUTHERN MINNESOTA AND WESTERN WISCONSIN. THIS
IS STEMMING FROM A POSITIVELY TILTED WEAK TROUGH WITH SOME EMBEDDED
SHORTWAVE ENERGY OVER THE NORTHERN PLAINS, WHICH COULD ALSO PRODUCE
SOME ISOLATED NON-ACCUMULATING SPRINKLES INTO THE OVERNIGHT HOURS
OVER SOUTHERN MINNESOTA WHERE THE CLOUD COVER WILL BE THE MOST
EXPANSIVE. THE FORECAST HAS GENERALLY TRENDED CLOUDIER AND THEREFORE
A DEGREE OR TWO WARMER COMPARED TO LAST NIGHT, WHICH HAS RESULTED IN
A LESS FAVORABLE ENVIRONMENT FOR FROST EVEN AS TEMPERATURES STILL
DROP INTO THE MID TO UPPER 30S ACROSS SOUTHERN MN AND LOW TO MID 30S
IN CENTRAL MN. THE ENTIRE AREA HAS YET TO FULLY ENTER THE GROWING
SEASON, WHICH ALONGSIDE THE INCREASED CLOUD COVER WITHIN THE
FORECAST HAS LED TO THE DECISION TO FOREGO A FROST ADVISORY FOR
TONIGHT IN FAVOR OF SAVING THOSE HEADLINES FOR THE FOLLOWING FEW
NIGHTS WHICH LOOK TO BE A FEW DEGREES COLDER AND MORE FAVORABLE.
THE AFOREMENTIONED TROUGH IS EXPECTED TO PIVOT OVER SOUTHERN ONTARIO
BEFORE SWINGING SOUTHWARDS OVER LAKE SUPERIOR, WITH ENOUGH CVA INTO
SOUTHERN MINNESOTA TO PRODUCE POCKETS OF INCREASED CLOUD COVER AND
SPRINKLE SHOWERS, WITH A NON-ZERO CHANCE FOR THUNDER MAINLY IN
SOUTHWEST MINNESOTA. TEMPERATURES ALOFT ARE BELOW FREEZING AND
PARTIAL CLOUD COVER WILL PREVENT COMPLETE MIXING, SO THE WEAK
SHOWERS MAY END UP PRODUCING ONLY VIRGA AS THEY STRUGGLE TO SATURATE
THE BOUNDARY LAYER ENOUGH TO REACH THE SURFACE. FORECAST SOUNDINGS
BY THE AFTERNOON SHOW INCREASE LOW LEVEL LAPSE RATES AND A VERY DRY
LAYER BELOW 750MB, WITH A SLIGHT INVERSION FROM 700 TO 600MB DUE TO
THE RELATIVELY WARM TEMPERATURES ALOFT VERSUS IN THE LOWER LEVELS.
WITH THESE FACTORS COMBINED, IT SEEMS FAIRLY UNLIKELY TO SEE
MEASURABLE PRECIPITATION, WITH THE MOST LIKELY CHANCE IN WESTERN WI
DURING THE AFTERNOON BUT STILL REMAINING HUNDREDTHS OF QPF AT THE
MOST.
NORTH TO NORTHWESTERLY FLOW ALOFT CONTINUES THROUGHOUT THE REST OF
THE WEEK, PROMOTING FURTHER CHANCES FOR FROST OR EVEN A HARD FREEZE
AS COLD AIR CONTINUES TO POOL OVER THE REGION. THE MAIN DRIVER
BEHIND A HARD FROST/FREEZE MAY END UP BEING IF WE CAN MANAGE TO
MAINTAIN EVEN SPORADIC CLOUD COVER OVERNIGHT, WITH THE SLIGHT
SUPPRESSION OF RADIATIONAL COOLING KEY IN PREVENTING TEMPERATURES
FROM DROPPING BELOW THE FREEZING MARK. OUR COLDER TEMPERATURES ALOFT
FINALLY PUSH EASTWARDS THE 2ND HALF OF SATURDAY AS NORTHWESTERLY
FLOW ALOFT MIXES WITH WINDS TURNING WESTERLY AND EVENTUALLY
SOUTHWESTERLY AT THE SURFACE AS A BROAD AREA OF SURFACE HIGH
PRESSURE DRIFTS THROUGH THE CENTRAL PLAINS. THIS SETS UP FOR OUR
NEXT CHANCE FOR LEGITIMATE RAINFALL, WHICH TEMPORALLY LOOKS MOST
LIKELY ON MONDAY DUE TO LOWER LEVEL WARM AIR ADVECTION/MOISTURE
ADVECTION COUPLED WITH A DIGGING TROUGH OVER THE SOUTHERN GREAT
LAKES, PRODUCING A DEGREE OF FRONTOGENESIS VIA A TIGHTENING
TEMPERATURES GRADIENT. THE SYNOPTIC FORCING ISN'T REMARKABLY STRONG,
BUT SHOULD BE ENOUGH TO PRODUCE SCATTERED SHOWERS ACROSS THE AREA
MONDAY AFTERNOON WHICH COULD ALSO CONTAIN SOME THUNDER IF WE ARE
ABLE TO MAINTAIN DECENT LOWER LEVEL LAPSE RATES CLOSE TO THE SURFACE
WARM FRONT. FOR NOW, THE AXIS OF HEAVIEST PRECIPITATION LOOKS TO BE
FROM CENTRAL IOWA THROUGH THE HARD HIT AREAS OF SOUTHERN WISCONSIN
AND INTO NORTHERN LOWER MICHIGAN, HOWEVER WE ARE FAR ENOUGH AWAY
WHERE TEMPORAL/SPATIAL DIFFERENCES WILL CONTINUE TO CHANGE THE
FORECAST UNTIL WE GET CLOSER.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1234 PM CDT TUE APR 28 2026
VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGHOUT THIS
DURATION. UPPER LEVEL CIRRUS HAS BEEN MAKING STEADY INROADS INTO
THE UPPER MIDWEST THE PAST COUPLE HOURS AND WILL CONTINUE TO DO
SO THROUGH THE REMAINDER OF THE DAY TODAY. UPPER LEVEL CEILINGS
LOOK LIKELY BY ABOUT SUNSET WITH SCT-BKN COVERAGE IN THE 080-120
HEIGHT RANGE TONIGHT THROUGH TOMORROW. BREEZY/GUSTY NW WINDS
WILL CONTINUE THROUGH SUNSET THEN GRADUALLY DIMINISH TO
LIGHT/VARIABLE OVERNIGHT THEN PICK UP AGAIN FROM THE NW AFTER
SUNSET TO NEAR 10KTS.
KMSP...NO ADDITIONAL CONCERNS.
/OUTLOOK FOR KMSP/
THU-SAT...VFR. WIND NW 5-10KTS.
SUN...MVFR CEILINGS PSBL. SLGT CHC -SHRA. WIND NW 5-10KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...NONE.
WI...NONE.
DISCUSSION...TDH
AVIATION...JPC
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