906
FXUS63 KMPX 150658
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
158 AM CDT THU MAY 15 2025
KEY MESSAGES
- INITIAL THUNDERSTORM COMPLEX MOVES ACROSS CENTRAL/SOUTHERN MINNESOTA
THROUGH DAYBREAK. STORMS ARE FORECAST TO WEAKEN AS THEY MOVE
EAST.
- ENHANCED RISK (LEVEL 3/5) FOR SEVERE WEATHER FROM EASTERN MINNESOTA
THROUGH MOST OF WISCONSIN THIS AFTERNOON. VERY LARGE HAIL,
DAMAGING WINDS, AND TORNADOES ARE ALL POSSIBLE.
- STRONG SOUTHWESTERLY WINDS FOLLOW THE FRONTAL PASSAGE THIS
EVENING AND CONTINUE INTO FRIDAY. WIND ADVISORY ISSUED ACROSS
SOUTHERN MINNESOTA WHERE GUSTS UP TO 50 MPH ARE POSSIBLE.
- COOLER, BELOW NORMAL TEMPERATURES FOR THE WEEKEND. WET WEATHER
RETURNS EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 158 AM CDT THU MAY 15 2025
SEVERE WEATHER POSSIBLE TODAY...REGIONAL RADAR CAPTURES ROBUST
CONVECTION ONGOING ACROSS SOUTHEASTERN SD/NORTHEASTERN NE. THE
STRONGEST ACTIVITY WAS LOCATED ON THE NOSE OF THE INSTABILITY
GRADIENT OVER NORTHEASTERN NE. AS ANTICIPATED, UPSCALE GROWTH INTO A
MATURE MCS IS UNDERWAY. WE'VE DISCUSSED THE POTENTIAL OUTCOMES IN
THE TRACK OF THIS COMPLEX OVER THE PAST FEW DISCUSSIONS. HREF'S CAM
ENSEMBLE HAS COME INTO PRETTY SOLID AGREEMENT THAT THE MCS WILL MOVE
INTO SOUTHWESTERN MINNESOTA AND CONTINUE ON A MORE NORTHEASTERLY
TRACK SUPPORTED BY THE MID TO UPPER LEVEL FLOW. EVEN AT THIS NEAR
TERM/NOWCAST FORECAST DISTANCE, IT STILL SEEMS CONCEIVABLE THAT THE
MCS TAKES A LITTLE BIT OF AN EASTERLY TURN ALONG THE INSTABILITY
GRADIENT, WHICH KEEPS AREAS LIKE THE TC METRO IN PLAY FOR CONVECTION
THROUGH MID-MORNING. THIS SCENARIO IS DISPLAYED BY THE 00Z RRFS.
ISOLATED DAMAGING WIND GUSTS AND LARGE HAIL ARE POSSIBLE AS THE
COMPLEX MOVES ACROSS SOUTHWEST MN, THOUGH WE DO EXPECT THE MCS TO
GRADUALLY DECAY AS MOVES EAST WITH TIME.
THE QUICK TRANSLATION OF A NEGATIVELY TILTED TROUGH OVER THE EASTERN
DAKOTAS WILL SUPPORT THE DEEPENING OF A CLIMATOLOGICALLY ANOMALOUS
~980S MB SURFACE LOW NEAR THE ND/SD/MN TRIPLE POINT. THE OCCLUSION
OF THE SURFACE CYCLONE WILL SEND AN ELONGATED COLD FRONT RAPIDLY
ACROSS MINNESOTA, WHICH WILL BE THE FOCUS FOR A POTENTIAL SEVERE
WEATHER EPISODE THIS AFTERNOON. AN EML, CHARACTERIZED BY A NARROW
PLUME 8-8.5C/KM MID-LEVEL LAPSE RATES, WILL OVERSPREAD SOUTHERN MN
FOLLOWING THE MORNING MCS. THIS WILL EFFECTIVELY WORK TO "CAP" THE
ATMOSPHERE, ALLOWING FOR EXTREME INSTABILITY TO BUILD ALOFT AHEAD OF
THE PRIMARY SEVERE WEATHER THREAT -- THOUGH IT SHOULD BE NOTED THAT
THIS WINDOW WILL LIKELY BE FAIRLY SHORT AS ATTEMPTS AT RENEWED
CONVECTIVE INITIATION ARE EXPECTED ACROSS EASTERN MN AS EARLY AS
LATE MORNING. ELEVATED CONVECTION NEAR THE SURFACE LOW WILL LIKELY
BE ONGOING ACROSS WESTERN/CENTRAL MN THROUGH THE MID-MORNING HOURS.
THERE COULD BE A FEW INSTANCES OF LARGE HAIL IN THIS CONVECTION,
HOWEVER THE GREATER THREAT OF SEVERE WEATHER WILL EXIST TO THE SOUTH
AND EAST. WHILE CLOUD DEBRIS FROM THE MORNING MCS/SLOW-TO-CLEAR
PRECIPITATION MAY PLAY A FACTOR IN THE EVENTUAL OUTCOME OF TODAY'S
SETUP, THERE IS HIGH CONFIDENCE THAT A RATHER VOLATILE ENVIRONMENT
CAPABLE OF PRODUCING ALL SEVERE WEATHER HAZARDS WILL TAKE SHAPE OVER
EASTERN MN/WESTERN WI BY LATE MORNING. A QUICK HIGHLIGHT OF THE
EXPECTED ENVIRONMENT ACROSS EASTERN MN/WESTERN WI INCLUDES MLCAPES
OF 2500+ J/KG (SUPPORTING ROBUST UPDRAFTS), MODESTLY STEEP MID-LEVEL
LAPSE RATES, SHIP VALUES BETWEEN 2.0-2.5 (INDICATES THE POTENTIAL
FOR SIGNIFICANT HAIL IN EXCESS OF 2"), ALONG WITH STRONG SHEAR.
CONVECTIVE MODE WILL BE A KEY PLAYER IN THE OCCURRENCE OF ANY SINGLE
HAZARD, BUT THIS TYPE OF ENVIRONMENT IS CAPABLE OF PRODUCING VERY
LARGE HAIL (2"+), DAMAGING WINDS (60+ MPH) AND TORNADOES (PERHAPS A
FEW STRONG TORNADOES). SPC MADE LITTLE CHANGE TO THE NEW DAY 1
OUTLOOK, AS FAR EASTERN MN AND ALL OF WESTERN WI REMAINING UNDER THE
ENHANCED RISK (3/5). MUCH OF THE REMAINING REAL ESTATE ACROSS THE
MPX COVERAGE AREA (CENTRAL/SOUTHERN MN) ARE UNDER THE SLIGHT RISK
(LEVEL 2/5).
THE THREAT ACROSS THE SLIGHT RISK AREA IS SOMEWHAT CONDITIONAL DUE
TO THE CAPPING AND QUICK TURNAROUND FROM THE MORNING CONVECTION,
WHICH MAY IN TURN LIMIT STORM COVERAGE. HOWEVER, CAMS CONTINUE TO
DISPLAY AN ARC OF ROBUST CONVECTION DEVELOPING BY EARLY AFTERNOON
ACROSS EAST CENTRAL MN SOUTHEAST INTO WESTERN WI. GIVEN THE
AFOREMENTIONED ENVIRONMENT AND STRONG SYNOPTIC SUPPORT, WOULD EXPECT
CONVECTION TO INTENSIFY QUICKLY. ESSENTIALLY THE ENHANCED RISK
SERVES AS THE AREA BY WHICH WIDESPREAD COVERAGE OF NUMEROUS SEVERE
THUNDERSTORMS ARE EXPECTED. SO WHILE ALL HAZARDS ARE POSSIBLE WITH
ANY STORMS THAT DEVELOP TODAY, THE GREATEST PROBABILITIES EXIST
ACROSS FAR EASTERN MN/WESTERN WI. ANOTHER ITEM TO WATCH WILL BE THE
UPSCALE EVOLUTION OF CONVECTION AS MATURES WITH EASTWARD MOVEMENT
INTO WI THIS AFTERNOON. SHOULD STORMS GROW INTO LINEAR SEGMENTS, A
MORE PRONOUNCED DAMAGING WIND THREAT MAY MATERIALIZE. CONVERSELY,
SHOULD SUPERCELLS REMAIN SEMI-DISCRETE, A GREATER TORNADO SCENARIO
IS ON THE TABLE. SPC HAS HIGHLIGHTED A LARGE SWATH OF WEST/CENTRAL
WI UNDER THE 10% SIG HATCHED AREA OF TORNADOES. CONVECTION WILL BE
MOVING QUICKLY GIVEN THE STRONG FLOW ALOFT, SO WE'LL BE ABLE TO GIVE
A HIGH CONFIDENCE "ALL CLEAR" FROM SOUTHWEST TO NORTHEAST WITH TIME
THIS AFTERNOON. TODAY IS NOT A "SLAM DUNK" SEVERE WEATHER DAY IN THE
TWIN CITIES GIVEN THE CONDITIONAL NATURE OF STORM COVERAGE, BUT IT
IS A DAY TO RESPECT THE SETUP AND BE READY TO RESPOND TO
WATCH/WARNING INFORMATION SHOULD SEVERE THUNDERSTORMS DEVELOP.
STRONG WINDS THIS EVENING/FRIDAY...SHORTLY AFTER THE DEPARTURE OF
CONVECTION, A "STING JET" SCENARIO AIMS TO SETUP ACROSS THE REGION.
THE TRANSLATION OF THE 700MB JETSTREAK AROUND THE UPPER-LOW WILL
DRIVE STRONG SOUTHWESTERLY WINDS TO THE SURFACE WITH GUSTS UP TO 50
MPH THIS AFTERNOON AND EVENING. WE'LL OBSERVE AN INCREASE IN WINDS
ACROSS THE ENTIRE REGION AS THIS PROCESS OCCURS, BUT IT'S SOUTH-
CENTRAL MINNESOTA WHERE THE FORECAST OF STRONGEST WINDS HAS PROMPTED
THE ISSUANCE OF A WIND ADVISORY. STRONG WINDS (45+ MPH), LINGERING
DEFORMATION PRECIPITATION, AND COOLER TEMPERATURES WILL MAKE FOR A
RATHER RAW DAY TOMORROW. THE POTENT SPRING STORM SYSTEM WILL BEGIN
TO DEPART SATURDAY, THOUGH IT WILL STILL BE BREEZY AND COOL WITH
HIGHS IN THE 50S. TEMPERATURES THEN CLIMB INTO THE 60S SUNDAY &
BEYOND, WITH THE RETURN OF RAIN CHANCES EARLY NEXT WEEK. LATEST NBM
ALREADY FEATURES 80%+ POPS IN THE TUESDAY TIMEFRAME...WHICH IS
REFLECTIVE OF NEARLY ALL ENSEMBLE MEMBERS DISPLAYING PRECIPITATION.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1151 PM CDT WED MAY 14 2025
A VERY COMPLEX TAF PERIOD WEATHER-WISE IS UPCOMING, WITH TWO
ROUNDS OF STORMS EXPECTED, FOLLOWED BY STRONG WINDS BEHIND A
COLD FRONT THURSDAY AFTERNOON. OVERALL LITTLE CHANGE FROM THE
INHERITED 00Z TAFS, SO WILL MAINTAIN MUCH OF THE WORDING FROM
THE PREVIOUS AFD:
THE FIRST ROUND OF STORMS WILL EVOLVE OUT OF THE CONVECTION
BLOWING UP OVER CENTRAL NEBRASKA AT THE START OF THE PERIOD.
THE GENERAL TIMING OF THE FIRST LINE FROM THE HRRR AND RRFS
STILL LOOKS GOOD AND REASONABLE. WITH THIS FIRST ROUND WILL
ALSO COME THE THREAT FOR OCCASIONAL MVFR CIGS, WITH SOUTHEAST
WINDS/GUSTS RAMPING UP AS WELL IN RESPONSE TO THE LOW DEEPENING
OVER THE EASTERN DAKOTAS. THERE CONTINUES TO BE PLENTY OF
UNCERTAINTY WITH WHERE/WHEN ROUND 2 GETS GOING, BUT AS ROUND 1
IS DIMINISHING NEAR THE MN/WI BORDER BETWEEN 16Z AND 18Z, ROUND
2 WILL BE FIRING UP OVER SOUTHWEST MN ON A NORTHEASTWARD
ADVANCING OCCLUDED FRONT. ONE THING THAT CAN BE SAID IS THAT
RWF/MKT HAVE THE BEST CHANCE AT MISSING THIS SECOND ROUND,
WITH ALL OTHER TERMINALS LIKELY TO SEE THE THREAT OF STRONG TO
SEVERE STORMS IN THE AFTERNOON. FINALLY, BEHIND THE COLD FRONT,
THERE IS GROWING CONCERN OF SOME VERY STRONG WIND GUSTS. RAP
SOUNDINGS AT RWF/MKT CONTINUE TO INDICATE UPWARDS OF 50 KTS ON
THE GUSTS AND EVEN THE LAV, WHICH CAN UNDERPLAY WIND SPEED
POTENTIAL SOME ON WINDY DAYS HAS SOME REALLY QUITE STRONG SSW
WINDS ALREADY BEHIND THE FRONT. WE'LL ALSO SEE A GOOD SLUG OF
WRAP-AROUND MOISTURE COMING IN TO THE SOUTH OF THE LOW, THOUGH
THAT WON'T REALLY START COMING INTO WESTERN MN UNTIL THE TAIL
END OF THIS PERIOD.
KMSP...SHRA POTENTIAL NUMBER 1 CONTINUES TO LOOK HIGHEST
BETWEEN 13Z AND 15Z, THOUGH THERE IS STILL SOME WIGGLE ROOM AN
HOUR ONE WAY OR ANOTHER ON THAT. THE TSRA RISK WITH THIS ROUND
LOOKS LOW THUS HAVE OMITTED ITS MENTION FOR THURSDAY MORNING,
ALTHOUGH IT IS NOT ENTIRE ZERO CHANCE. ROUND 2 IS MORE
CONCERNING FROM THE SEVERE PERSPECTIVE AND 18Z TO 20Z IS THE
GREATEST THREAT FOR STORMS THEN. STORMS WILL ONLY LAST 30 TO 45
MINUTES, BUT WILL PACK QUITE THE PUNCH. AND THE FUN IS NOT DONE
AFTER THAT LINE OF STORMS. BEHIND THIS FRONT WE COULD SEE VERY
STRONG WINDS, THAT WILL BE MOSTLY CROSS FOR RUNWAY 12/30. MIX
DOWN PROCEDURES ON BUFKIT SOUNDINGS FROM THE RAP SHOWS POTENTIAL
FOR 40+ KT WIND GUSTS IN THIS POST FRONTAL ENVIRONMENT.
/OUTLOOK FOR KMSP/
SAT...MVFR MRNG CIGS LIKELY. WIND NW 10-15G20-25 KTS.
SUN...VFR. WIND NE 5-10 KTS.
MON...MAINLY VFR. CHANCE MVFR/SHRA. WIND ESE 10-15G25KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 9 PM CDT THIS
EVENING FOR BLUE EARTH-FARIBAULT-FREEBORN-MARTIN-STEELE-
WASECA-WATONWAN.
WI...NONE.
DISCUSSION...STRUS
AVIATION...JPC/MPG
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