364
FXUS63 KMPX 170909
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
409 AM CDT SUN MAY 17 2026
KEY MESSAGES
- SEVERE THUNDERSTORMS LIKELY TONIGHT WITH DAMAGING WIND GUSTS
THE PRIMARY HAZARD. THE HIGHEST THREAT IS ACROSS SOUTHERN
MINNESOTA.
- ANOTHER ROUND OF THUNDERSTORMS IS LIKELY MONDAY NIGHT. SEVERE
THUNDERSTORMS ARE POSSIBLE ACROSS SOUTHEAST MINNESOTA &
WESTERN WISCONSIN.
DISCUSSION
ISSUED AT 257 AM CDT SUN MAY 17 2026
ISOLATED RAIN SHOWERS HAVE DEVELOPED ON CUE OVERNIGHT, DRIVEN BY
FORCING ON THE NOSE OF STRONG LOW & MID-LEVEL WARM ADVECTION
FROM THE LOW-LEVEL JET. THESE SHOWERS ARE EXPECTED TO DISSIPATE
AFTER SUNRISE AS THE LOW-LEVEL JET WANES IN INTENSITY, BUT
ANOTHER REGION OF SHOWERS & THUNDERSTORMS IS LIKELY TO CONTINUE
OVER SOUTHEASTERN MINNESOTA & WEST-CENTRAL MINNESOTA AS A MCV
FROM OVERNIGHT CONVECTION ACROSS IOWA MOVES THROUGH THE AREA.
THE MAIN TREND TO WATCH THIS MORNING & AFTERNOON WILL BE HOW
OUR TEMPERATURES & DEWPOINTS RESPOND THROUGH THE DAY. WE ARE
CURRENTLY SITTING UNDER STRONG NORTHEASTERLY FLOW, & WILL
REMAIN COOL & DRY UNTIL WINDS BECOME MORE SOUTHEASTERLY & ALLOW
FOR DEWPOINTS TO RISE INTO THE UPPER 50S & 60S. CONFIDENCE IS
HIGH THAT WE'LL SEE THESE MORE UNSTABLE CONDITIONS DEVELOP
ACROSS SOUTHERN MINNESOTA, BUT IT'S MORE UNCERTAIN HOW FAR NORTH
INTO CENTRAL MINNESOTA & WESTERN WISCONSIN WE'LL SEE
TEMPERATURES IN THE 70S & DEW POINTS NEAR 60 EXTEND BY LATE
AFTERNOON. WIDESPREAD CLOUD COVER THROUGH THE DAY WILL PUT A
LIMIT ON THE EXTENT OF SOLAR HEATING THIS AFTERNOON, SO WATCHING
WHERE WINDS BECOME SOUTHEASTERLY THIS AFTERNOON WILL BE KEY ON
IDENTIFYING WHERE THE ENVIRONMENT FOR SEVERE WEATHER EXISTS
LATER THIS EVENING.
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON
ACROSS THE ASTERN DAKOTAS, NEAR THE TRIPLE POINT OF A LOW
FORECAST TO TRACK NORTHEASTWARDS FROM THE CENTRAL PLAINS INTO
MINNESOTA & WISCONSIN. THESE STORMS WILL LIKELY BECOME
SUPERCELLULAR GIVEN THE IMPRESSIVE ENVIRONMENT FOR SEVERE
WEATHER OVER THE DAKOTAS & CENTRAL PLAINS, BUT WILL LIKELY
MERGE INTO A LINEAR MCS AND/OR MULTIPLE LINE SEGMENTS AS THEY
MOVE INTO WESTERN MINNESOTA AROUND 7-9 PM THIS EVENING. ALL
MODES OF SEVERE WEATHER WILL BE POSSIBLE WITH THESE INITIAL
SUPERCELLULAR STORMS, WITH VERY LARGE HAIL (2-3" IN DIAMETER) &
A FEW TORNADOES ACCOMPANYING A DAMAGING WIND THREAT. AS THE
DISCRETE STORMS TRANSITION TO A MCS OR LINE SEGMENTS, DAMAGING
WIND GUSTS WILL BECOMING THE PREDOMINANT SEVERE THREAT, ALTHOUGH
A FEW QLCS TORNADOES ARE ALSO POSSIBLE GIVEN THE SOUTHEASTERLY
FLOW AHEAD OF THE STORMS GENERATING IMPRESSIVE LOW-LEVEL WIND
SHEAR & HELICITY. AS MENTIONED ABOVE, WHERE SOUTHEASTERLY WIND
DEVELOP & ALLOW MORE INSTABILITY IS GOING TO BE KEY FOR
DETERMINING WHERE THE SEVERE THREAT FROM THESE THUNDERSTORMS IS
GOING TO CONTINUE INTO THE EVENING AS STORMS MOVE EASTWARDS
ACROSS MINNESOTA & WISCONSIN. HIGH-RESOLUTION ENSEMBLE GUIDANCE
REALLY HIGHLIGHTS SOUTHERN MINNESOTA FOR THE GREATEST SEVERE
ENVIRONMENT, UP TO THE LATITUDE OF MARSHALL/MANKATO/RED WING,
WHERE WE SEE THE POTENTIAL FOR SURFACE-BASED CAPE VALUES
APPROACHING 1000 J/KG. HOWEVER, WE COULD STILL SEE A LOW
CAPE/HIGH-SHEAR ENVIRONMENT EXTEND NORTHWARDS INTO CENTRAL
MINNESOTA & WESTERN WISCONSIN AS LONG AS STORMS ARE STILL ABLE
TO TAP INTO SOME SORT OF SURFACE- BASED INSTABILITY. VARIOUS
HIGH-RESOLUTON MODEL SOLUTIONS TEND TO DEPICT THE HIGHEST
CONCENTRATION OF DAMAGING WIND GUSTS & QLCS TORNADO POTENTIAL
MAINLY OCCURRING ACROSS THIS REGION OF SOUTHERN MINNESOTA, BUT
SOME POTENTIAL STILL EXISTS FARTHER TO THE NORTH & EAST.
TIMING- WISE, HIGH-RESOLUTION MODELS ARE GENERALLY IN AGREEMENT
WITH MOVING THE THUNDERSTORM COMPLEX REACHING WESTERN MN THROUGH
7-9 PM, CENTRAL MN & THE METRO BETWEEN 9-11 PM, & WESTERN WI
BETWEEN 11 PM - 1 AM.
THE THUNDERSTORMS WILL BEGIN WEAKENING AROUND MIDNIGHT AS
INSTABILITY WANES, LIKELY REDUCING THE THREAT FOR SEVERE
WEATHER ACROSS WESTERN WISCONSIN. SHOWERS & THUNDERSTORMS WILL
STILL BE ONGOING INTO THE OVERNIGHT HOURS, WITH THE
PRECIPITATION MOSTLY OVER ACROSS OUR AREA BY SUNRISE. FOR
MONDAY, WE WILL LIKELY BE DRY THROUGH THE DAY BUT WILL HAVE TO
MONITOR WHERE ANY OUTFLOW BOUNDARIES OR REMNANT FROM MCVS FROM
THE OVERNIGHT STORMS SET UP DURING THE DAY. ANOTHER ROUND OF
SHOWERS & THUNDERSTORMS IS LIKELY MONDAY NIGHT, BUT WE WILL
LIKELY REMAIN NORTH OF THE BEST SYNOPTIC ENVIRONMENT FOR SEVERE
WEATHER ACROSS IOWA & SOUTHERN WISCONSIN. CAN'T RULE OUT
SOMETHING INTERESTING HAPPENING IF WE GET A MESOSCALE BOUNDARY
TO SET UP ACROSS OUR AREA MONDAY EVENING, BUT OTHERWISE WE'RE
LOOKING AT MOSTLY A RAIN EVENT. RAINFALL-WISE, WE'LL SEE OUR
FIRST SOAKING RAINFALL OF THE MONTH WITH MOST OF THE AREA
EXPECTED TO SEE AT LEAST 1-2" BETWEEN THE THUNDERSTORMS TONIGHT
& MONDAY NIGHT. LOCALIZED AMOUNTS OF 3-4" LOOK POSSIBLE BASED
ON INDIVIDUAL HIGH- RESOLUTION MODEL RUNS, DEPENDING ON WHICH
AREAS GET THE SLOWEST- MOVING THUNDERSTORMS.
BY TUESDAY, SEASONABLY COOL & DRY WEATHER RETURNS AS THE UPPER
MIDWEST RETURNS TO A PATTERN OF TROUGHING ALOFT. THE NEXT ROUND
OF DISTURBANCES & PRECIPITATION ARRIVES FRIDAY, WITH ADDITIONAL
CHANCES FOR SHOWERS & THUNDERSTORMS LATER ON THE MEMORIAL DAY
WEEKEND
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 257 AM CDT SUN MAY 17 2026
ISOLATED SHOWERS WILL CONTINUE THROUGH SUNRISE WITH BRIEF MVFR
VISIBILITY POSSIBLE DURING DOWNPOURS. A LIGHTNING STRIKE OR TWO
CAN NOT BE RULED OUT. ONCE THESE SHOWERS DISSIPATE THIS MORNING
WE SHOULD STAY DRY UNTIL AT LEAST MID-AFTERNOON, WHEN WE COULD
SEE SOME SCATTERED RAIN SHOWERS BEGIN TO DEVELOP ACROSS EASTERN
MINNESOTA & WESTERN WISCONSIN. THE MAIN WEATHER TO WATCH THIS
PERIOD WILL BE STRONG TO SEVERE THUNDERSTORMS DEVELOPING ACROSS
THE EASTERN DAKOTAS LATE THIS AFTERNOON/EARLY THIS EVENING, &
THEN MOVING EASTWARDS ACROSS MN & WI THROUGH THE NIGHT. DAMAGING
WIND GUSTS ARE POSSIBLE WITH THE STRONGEST CORES OF THESE
STORMS, & LARGE HAIL & A TORNADO OR TWO CAN'T BE RULED OUT
EARLIER IN THE EVENING ACROSS SOUTHWEST MINNESOTA. THE TIMING
FOR THESE STORMS IS GENERALLY INTO WESTERN MINNESOTA BETWEEN 7-9
PM, THROUGH CENTRAL MN & THE METRO BETWEEN 9-11 PM, & WESTERN
WI BETWEEN 11PM - 1 AM.
CEILINGS WILL LOWER THROUGH THE MORNING WITH MVFR CONDITIONS
EXPECTED AT MOST SITES BY EARLY AFTERNOON, & IFR CEILINGS
POSSIBLE BY EVENING. NORTHEAST WINDS BECOME MORE EASTERLY THIS
MORNING WITH SPEEDS INCREASING INTO THE AFTERNOON. GUSTS UP TO
25-30 KTS ARE LIKELY.
KMSP...A BRIEF RAIN SHOWER IS POSSIBLE AROUND SUNRISE BUT
OTHERWISE WE SHOULD STAY DRY UNTIL THIS EVENING. TIMING ON THE
STRONG TO SEVERE THUNDERSTORM POTENTIAL THIS EVENING LOOKS TO
BE 9 PM AT THE EARLIEST, MOST LIKELY BETWEEN 10 PM TO MIDNIGHT,
& THE LIGHTNING OUT OF THE AREA BY 1-2 AM.
/OUTLOOK FOR KMSP/
MON...-SHRA/-TSRA LIKELY, IFR/MVFR. WIND N 10-15 KTS.
TUE...MVFR CIGS. WIND NW 10-15G25KTS.
WED...VFR. WIND NNW 5-10KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...NONE.
WI...NONE.
DISCUSSION...ETA
AVIATION...ETA
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