809
FXUS63 KMPX 181758
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1258 PM CDT SUN MAY 18 2025
KEY MESSAGES
- AREAS OF FROST POSSIBLE IN EASTERN MN AND WEST-CENTRAL WI
SUNDAY NIGHT.
- NEXT CHANCE FOR SOAKING RAIN ARRIVES MONDAY INTO TUESDAY, WITH
HIGHEST CHANCES IN WESTERN MN AND ALONG I-90, LOWEST CHANCES
NORTH OF I-94. SEVERE WEATHER IS NOT EXPECTED.
DISCUSSION
ISSUED AT 310 AM CDT SUN MAY 18 2025
TEMPERATURES HAVEN'T FALLEN MUCH OVERNIGHT AS STRATUS CLOUDS HAVE
BEEN STUBBORN TO CLEAR. CURRENT LOW TO MID 40S DON'T SIGNAL AN
ABUNDANCE OF FROST FOR EARLY THIS MORNING. BUT, STILL THINKING WEST-
CENTRAL MN COULD SEE SOME AREAS OF FROST BEFORE SUNRISE. JUST LIKELY
NOT AS WIDESPREAD AS PREVIOUS THINKING. THE LOW STRATUS SHOULD BEGIN
TO CLEAR FROM WEST TO EAST STARTING AROUND MID-MORNING IN WESTERN MN
AND EARLY AFTERNOON IN EASTERN MN. SOME PEAKS OF SUN SHOULD ALLOW US
TO WARM INTO THE 50S, BUT HAVE DECREASED SUNDAY'S HIGHS SLIGHTLY
FROM THE PREVIOUS FORECAST. CHANCES FOR FROST MIGRATE TO EASTERN MN
AND NORTHWEST WI SUNDAY NIGHT AS LOWS IN THIS REGION ARE FORECAST TO
FALL INTO THE LOW TO MID 30S. ELSEWHERE, UPPER 30S TO LOWER 40S ARE
LIKELY. OVERCAST SKIES WILL AGAIN BUILD IN FROM THE SOUTHWEST AS OUR
NEXT STORM SYSTEM APPROACHES.
AN AMPLIFIED UPPER-LEVEL TROUGH WILL CROSS THE ROCKIES SUNDAY NIGHT
AND BRIEFLY STALL OVER THE CENTRAL PLAINS MONDAY AS A CUTOFF LOW.
THE LEADING MID-LEVEL VORTICITY MAX IS FORECAST TO SETTLE OVER SD,
CAUSING SOUTH-SOUTHEASTERLY WAA AND MOISTURE ADVECTION TO ITS EAST.
THIS FLOW SHOULD BE CENTERED OVER EASTERN SD AND WESTERN TO SOUTHERN
MN ALLOWING THE VERTICAL PROFILE IN THESE REGIONS TO SATURATE.
ROUNDS OF SHOWERS AND THUNDERSTORMS (NOT EXPECTED TO BE SEVERE) WILL
BEGIN MONDAY MORNING. MEANWHILE, AREAS TO THE NORTH AND EAST WILL
LIKELY REMAIN DRY FOR MUCH OF MONDAY DUE TO BEING REMOVED FROM THE
ADVECTION. WITH LITTLE EASTWARD ADVANCEMENT OF RAIN FORECAST DURING
MONDAY DUE TO THE STALLED NATURE OF THE FLOW, HAVE DELAYED THE
ARRIVAL OF HIGHER POPS FOR EASTERN MN AND WI UNTIL MONDAY
EVENING/NIGHT. THIS IS WHEN THE SECOND EMBEDDED WAVE WITHIN THE
UPPER-LEVEL TROUGH PIVOTS INTO THE MIDWEST, ALLOWING FOR SECONDARY
SURFACE CYCLOGENESIS TO OCCUR OVER IA. MUCH GREATER SYNOPTIC LIFT
AND MOISTURE ADVECTION INTO THE UPPER MIDWEST SHOULD CAUSE A
PRECIPITATION SHIELD TO FORM NORTH OF THE LOW. MOST OF OUR CWA WILL
BECOME COVERED BY STRATIFORM RAIN MONDAY NIGHT INTO TUESDAY WITH
RAIN LIKELY NOT STOPPING UNTIL AT LEAST TUESDAY NIGHT. ONLY OUR
NORTHERN COUNTIES COULD FLIRT WITH LESS TO NO RAIN DUE TO DRY AIR TO
OUR NORTH. THE RAIN LOOKS TO REMAIN WITH US INTO WEDNESDAY (THOUGH
TAPERING OFF) BEFORE FINALLY ENDING AS THE UPPER-LEVEL TROUGH EXITS
EAST INTO THE OHIO VALLEY. WE SHOULD SEE A WIDESPREAD SOAKER DUE TO
THE RAIN'S LONG DURATION, BUT REALLY SIGNIFICANT RAIN TOTALS DON'T
SEEM LIKELY AS WIDESPREAD CONVECTIVE POTENTIAL WITH THIS SYSTEM IS
LOW. MEAN QPF FROM THE GRAND ENSEMBLE HAS 1.5-2" FOR WESTERN TO
SOUTHERN MN WITH AMOUNTS DECREASING TO THE NORTHEAST. HIGHER AMOUNTS
ARE POSSIBLE, PARTICULARLY IN SOUTHWESTERN MN AND ALONG I-90 IF
TRAINING FROM MULTIPLE ROUNDS OF RAIN CAN OCCUR. THERE IS A SMALL
CHANCE LOCALIZED, RURAL FLOODING MAY OCCUR IN THESE REGIONS IF
RAINFALL TOTALS END UP ON THE HIGHER END OF THE DISTRIBUTION.
THE PATTERN QUIETS DOWN AFTER MID-WEEK AS GUIDANCE SHOWS NORTHWEST
FLOW PREVAILING OVER THE NORTHERN PLAINS/UPPER MIDWEST. TEMPERATURES
LOOK TO RETURN TO NORMAL WITH HIGHS NEAR 70 CURRENTLY FORECAST
THROUGH SUNDAY. RAIN CHANCES DO TRY TO CREEP BACK INTO THE PICTURE
NEXT WEEKEND AS ONE OR TWO IMPULSES WITHIN THE NORTHWEST FLOW TRAVEL
THROUGH THE UPPER GREAT LAKES. THOUGH, FORECAST CERTAINTY IS
CURRENTLY LOW GIVEN THE LARGE MODEL SPREAD BETWEEN THESE
FEATURES.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1258 PM CDT SUN MAY 18 2025
AVIATION...A FEW SITES HAVE BEEN LUCKY TO BREAK INTO CLEAR SKIES
THIS AFTERNOON OTHERWISE SCATTERED LOW VFR CIGS PREVAIL.
NORTHWESTERLY WINDS AROUND 10KTS WILL SHIFT GRADUALLY TO THE
NORTHEAST OVER THE NEXT FEW HOURS AND EVENTUALLY EAST BY TOMORROW
MORNING. MID-LEVEL CLOUDS ARE EXPECTED TO MIX IN AS THE NIGHT
PROGRESSES AS OUR NEXT SYSTEM APPROACHES FROM THE WEST. WIND GUSTS
ARE EXPECTED TO INCREASE BETWEEN 20-30KTS FOR AXN AND RWF TONIGHT
AND REMAINING SITES NEAR 12Z. RAIN SHOWERS ARE POSSIBLE ESPECIALLY
FOR RWF AND MKT BETWEEN 11-14Z. WIDESPREAD PRECIPITATION LOOKS TO
HOLD OFF UNTIL NEXT PERIOD.
KMSP...WINDS WILL CONTINUE TO SHIFT NE BECOMING A CROSSWIND TO
12/30S AFTER 22Z AND THEN BECOMING EASTERLY AROUND 6Z. BKN TO OVC
MID-LEVEL CIGS BEGIN TO MIX IN OVERNIGHT WITH INCREASING WIND GUSTS
TOMORROW MORNING AS A SYSTEM APPROACHES FROM THE WEST. BEST SHOT OF
PRECIP LOOKS TO REACH MSP DURING THE NEXT PERIOD BUT DID INTRODUCE A
PROB30 FOR THE CHANCE OF FEW CONVECTIVE SHOWERS LATE AFTERNOON.
/OUTLOOK FOR KMSP/
TUE...MVFR/SHRA LIKELY, CHC -TSRA/IFR. WIND NE 15-20G30KTS.
WED...MVFR/-SHRA EARLY, THEN VFR. WIND NE 5-10KTS.
THU...VFR. WIND NW 5-10KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...NONE.
WI...NONE.
DISCUSSION...CTG
AVIATION...DUNLEAVY
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