744
FXUS63 KMPX 141131
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
631 AM CDT WED MAY 14 2025
KEY MESSAGES
- MARGINAL FIRE WEATHER CONCERNS CONTINUE OVER FAR WESTERN MN TODAY,
BUT THE OVERALL FIRE WEATHER SCENARIO HAS IMPROVED.
- ENHANCED (LEVEL 3 OF 5) RISK FOR SEVERE WEATHER ACROSS WESTERN
WI THURSDAY AFTERNOON AND EVENING. SLIGHT (LEVEL 2 OF 5) RISK
ACROSS EASTERN MN. LARGE HAIL, DAMAGING WINDS, AND A FEW
TORNADOES ARE POSSIBLE.
- STRONG WINDS (45-50+ MPH) USHER IN MUCH COOLER AIR HEADING INTO
THE WEEKEND.
DISCUSSION
ISSUED AT 309 AM CDT WED MAY 14 2025
TODAY...SATELLITE IMAGERY REVEALS A RELATIVELY CLEAR PICTURE ACROSS
THE REGION, THOUGH THERE IS A POCKET OF STRATUS OVER FAR SE MN/W WI.
MESOANALYSIS SUGGESTS THIS STRATUS HAS DEVELOPED IN ASSOCIATION WITH
MOISTURE (LOW 60S TDS) THAT IS ADVECTING TO THE NORTHWEST. IN FACT,
YOU CAN SEE THE VERY GENTLE NORTHWEST PROGRESSION OF THE STRATUS
WHEN LOOKING AT THE SATELLITE LOOP. WE SAW THE FIRST SIGNS OF
MOISTURE RETURN VIA THE CU FIELD THAT BLOSSOMED OVER MUCH OF THE
REGION TUESDAY, AND WOULD SUSPECT MORE OF THE SAME TODAY. THE
INCREASE IN MOISTURE HAS WORKED TO EFFECTIVELY END THE MULTI-DAY
STRETCH OF CRITICAL FIRE WEATHER CONDITIONS ACROSS CENTRAL/SOUTHERN
MN & WESTERN WI. THAT BEING SAID, WE'LL STILL NOTE NEAR-CRITICAL
FIRE WEATHER CONDITIONS ACROSS FAR WESTERN MN THIS AFTERNOON GIVEN
MARGINAL RH'S AROUND 25 PERCENT, BREEZY WINDS, AND DRY FUELS.
OTHERWISE, IT WILL BE ANOTHER WARM DAY WITH HIGHS RANGING FROM THE
LOW 80S IN WESTERN WI TO THE UPPER 80S IN WESTERN MN. MOST OF THE
AREA WILL STAY DRY WITH THE PRESENCE OF THE DIURNAL CU, HOWEVER WE
DO ANTICIPATE THE DEVELOPMENT OF AIRMASS THUNDERSTORMS WITHIN THE
MOISTURE PLUME ACROSS WESTERN WI THIS AFTERNOON. HAVE REFLECTED THIS
WITH ~20/30 POPS EAST OF THE THE MN/WI BORDER. THERE IS ALWAYS
SOMEWHAT OF A CHAOTIC NATURE TO THE EVOLUTION OF THIS TYPE OF
CONVECTIVE REGIME, THUS SOME UNCERTAINTY EXISTS WITH HOW FAR WEST
STORMS DEVELOP. A FEW CAM SOLUTIONS TEASE THE IDEA OF ISOLATED
CONVECTION DEVELOPING AS FAR WEST AS I-35/TC. THIS IS CERTAINLY
PLAUSIBLE GIVEN THE LACK OF CAPPING AND MOISTURE ADVECTION OWING TO
A BROAD REGION OF MLCAPES IN EXCESS OF 500 J/KG ACROSS SE MN/WESTERN
WI. NO SEVERE WEATHER IS EXPECTED WITHIN THIS CONVECTIVE REGIME AND
STORMS SHOULD DISSIPATE WITH THE LOSS OF HEATING THIS EVENING.
TONIGHT/THURSDAY MORNING...AS A MENTOR ONCE SAID, "YOU DO NOT BREAK
A PERSISTENT HOT AND DRY PATTERN QUIETLY." THAT STATEMENT APPEARS TO
RING TRUE OVER THE NEXT 48 OR SO HOURS, AS A COUPLE OF ROUNDS OF
SHOWERS AND THUNDERSTORMS (WITH POTENTIAL SEVERE WEATHER) ARE
FORECAST ACROSS THE UPPER MIDWEST. WE CAN ALREADY SEE SIGNS OF A
PATTERN CHANGE LOOKING WEST ON GOES GEO-COLOR IMAGERY THIS MORNING,
AS ROBUST CONVECTION HAS ERUPTED ACROSS EASTERN WY/MT WITHIN THE
EXIT REGION OF AN INCOMING LONGWAVE TROUGH. THE EASTWARD
PROGRESSION OF THE TROUGH WILL BE THE FOCUS FOR RENEWED
CONVECTION ACROSS THE DAKOTAS THIS AFTERNOON. THERE IS GROWING
CAM SUPPORT THAT THIS CONVECTION WILL MATURE UPSCALE INTO A WELL
DEFINED LINE OR FORWARD-PROPAGATING MCS THAT ORIGINATES OVER
SD/NE. HREF'S CAM ENSEMBLE PAINTBALL POINTS TOWARDS A
NORTHEASTERLY MOTION OF THE MCS INTO SW MN AFTER MIDNIGHT AND
CONTINUING EAST/NORTHEAST THROUGH THE FIRST FEW HOURS AFTER
DAYBREAK. THIS SCENARIO WOULD SUGGEST THAT THE CONVECTION IS
ROOTED WITHIN THE MID TO UPPER LEVEL FLOW. ANOTHER POSSIBLE
SCENARIO IS MORE OF AN EASTERLY OR PERHAPS EVEN SOUTHEASTERLY
MOTION OF THE MCS WHICH FOLLOWS THE CAPE GRADIENT ALONG
I-90/INTO NORTHERN IA. OUR LATEST FORECAST PACKAGE LEANS IN THE
DIRECTION OF THE FIRST SCENARIO, WHICH SUPPORTS A BAND OF
DECAYING CONVECTION MOVING FROM SOUTHWEST TO NORTHEAST ACROSS
CENTRAL/SOUTHERN MN TO OPEN THURSDAY MORNING. SPC'S DAY 1
OUTLOOK FEATURES A MARGINAL (LEVEL 1 OF 5) RISK ACROSS
SOUTHWESTERN MN FOR ISOLATED INSTANCES OF DAMAGING WIND AND
LARGE HAIL AS THE CONVECTION ENTERS THE STATE.
SEVERE WEATHER THREAT THURSDAY AFTERNOON/EVENING...THE FORECAST
EVOLUTION OF THE TROUGH INTO A POTENT NEGATIVELY-TILTED UPPER LOW
WILL BE THE FOCUS POINT FOR A POTENTIAL EPISODE OF SEVERE WEATHER
THURSDAY AFTERNOON AND EVENING. BY MIDDAY THURSDAY, A MATURE ~980S
MB SURFACE LOW IS FORECAST TO BE POSITIONED NEAR THE MN/SD BORDER.
THE INITIAL ROUND OF MORNING CONVECTION WILL HAVE DISSIPATED OR
LIFTED NORTH OF I-94 BY THIS TIME, WHICH SHOULD ALLOW FOR
ENVIRONMENTAL RECOVERY SUPPORTED BY THE ADVECTION OF A WING OF HIGH
THETA-E RICH AIR. FROM A BIG PICTURE PERSPECTIVE, STRONG DIFFLUENCE
IN THE EXIT REGION OF THE UPPER LOW WILL BE THE FOCUS FOR RENEWED
CONVECTIVE INITIATION, WHETHER THAT IS AHEAD OF A MORE DEFINED
FRONTAL BOUNDARY OR ASSOCIATED WITH A REMNANT OUTFLOW FROM THE
MORNING CONVECTION REMAINS TO BE SEEN. NONETHELESS, FORECAST
SOUNDINGS SHOW AN ENVIRONMENT SUPPORTIVE ALL SEVERE WEATHER HAZARDS
ACROSS EASTERN MN AND WESTERN WI. AT FIRST GLANCE, THE POTENTIAL FOR
LARGE HAIL IS STRIKING GIVEN THE FORECAST OF CAPE IN NEAR/IN EXCESS
OF ~2500 J/KG, MODESTLY STEEP LAPSE RATES, AND SHIP VALUES NEAR ~2.0
(WHICH SUPPORTS LARGE HAIL IN EXCESS OF 1.5"). FOR REFERENCE, ONE OF
THE RAP SOUNDINGS THAT I PULLED FEATURED AN MPX ANALOG OF 1.75"
HAIL. OF COURSE, THE THREAT FOR LARGE HAIL IS GOING TO BE DEPENDENT
ON STORM MODE. ON THAT NOTE, WE SHOULD DISCUSS HOW CONVECTIVE
INHIBITION WILL PLAY A ROLE IN WHY THIS SETUP IS SOMEWHAT
CONDITIONAL (ESPECIALLY ACROSS EASTERN MN). AN EML WILL ADVECT
NORTHEAST ACROSS SOUTH CENTRAL MN FOLLOWING THE MORNING CONVECTION.
THIS EML EFFECTIVELY "CAPS" THE ATMOSPHERE AND WILL ALLOW FOR THE
EXTREME INSTABILITY TO BUILD ALOFT. IT'S THE STRENGTH OF THE CAP AND
ATTEMPTS AT CONVECTIVE INITIATION THAT WILL DETERMINE JUST HOW
QUICKLY STORMS DEVELOP THURSDAY AFTERNOON (AND HOW LONG THEY REMAIN
SEMI-DISCRETE). THE SOMEWHAT CONDITIONAL START TO THE FORECAST
BECOMES ONE OF HIGHER CONFIDENCE FOR ALL HAZARDS AS STORMS MOVE INTO
WESTERN WI THROUGH THE AFTERNOON. IT'S HERE THAT VERY LARGE HAIL,
DAMAGING WINDS, AND THE THREAT FOR A FEW TORNADOES WILL EXIST GIVEN
THE EXTREME INSTABILITY, LOW-LEVEL CURVATURE OF THE HODOGRAPH, AND
STRONG FORCING ALOFT.
SPC'S LATEST DAY 2 OUTLOOK MAINTAINS THE ENHANCED (LEVEL 3 OF 5)
RISK ACROSS WESTERN WI, WHERE CONFIDENCE IS HIGHEST IN THE
DEVELOPMENT OF AN ARC OF ROBUST SEMI-DISCRETE/LINEAR CONVECTION.
THIS HAS BEEN DISPLAYED ACROSS THE GUIDANCE (INCLUDING THE EURO'S
LIGHTNING DENSITY DISPLAY) OVER SEVERAL RUNS. SPC PULLED THE SLIGHT
(LEVEL 2 OF 5) RISK WEST OF THE TC METRO AS SOME OF THE CAMS ARE
DEVELOPING CONVECTION A LITTLE FARTHER WEST THAN BEFORE. THE
NORTHEASTERLY DEPARTURE OF THE EXPECTED ARC OF CONVECTION WILL END
THE THREAT FOR SEVERE WEATHER FROM WEST TO EAST THROUGH BY EARLY
THURSDAY EVENING.
LATE THURSDAY & BEYOND...THE ~980S MB SURFACE LOW WILL OCCLUDE OVER
CENTRAL MN THROUGH THURSDAY EVENING. THE FORECAST POSITION AND
TRANSLATION OF THE 700MB JET STREAK AROUND THE UPPER-LOW OVER
SOUTHERN MN WILL BE THE FOCUS POINT FOR A "STINGER JET" SCENARIO,
WHERE VERY STRONG WINDS (POSSIBLY IN EXCESS OF 50 MPH PER THE EPS)
STRENGTHEN THURSDAY EVENING AND PERSIST INTO FRIDAY. IT'S POSSIBLE
WE MAY NEED SOME SORT OF WIND HEADLINE ASSOCIATED WITH THIS FEATURE
SHOULD CONFIDENCE CONTINUE TO INCREASE. STRONG WINDS, COLD AIR
ADVECTION, AND LINGERING RAIN SHOWERS TIED TO THE SURFACE CYCLONE
WILL CREATE A RATHER RAW DAY OF MAY WEATHER ON FRIDAY. TEMPERATURES
FALL INTO THE 50S/LOW 60S FRIDAY AFTERNOON, WITH CONTINUED COOLING
TOWARDS AREAWIDE 50S ON SATURDAY. TEMPERATURES THEN CLIMB BACK INTO
THE 60S SUNDAY/EARLY NEXT WEEK. GUIDANCE DISPLAYS THE NEXT CHANCE AT
WIDESPREAD RAIN IN THE TUESDAY TIMEFRAME.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1234 AM CDT WED MAY 14 2025
VFR CONDITIONS EXPECTED THROUGHOUT THIS TAF SET, BUT THERE WILL
BE MID-LEVEL CEILINGS DEVELOPING MAINLY OVER EASTERN MN INTO
WESTERN WI MID-TO-LATE DAY. OTHERWISE, A DECENT CUMULUS FIELD IS
LIKELY ACROSS ALL OF CENTRAL-SOUTHERN MN INTO WESTERN WI. SOME
SCATTERED SHRA/TSRA IS POSSIBLE IN SOUTHWESTERN WI LATE
AFTERNOON, MAINLY IMPACTING EAU AND POSSIBLY RNH, BUT SHOULD
STAY FAR ENOUGH EAST AND NOT IMPACT ANY OTHER TERMINALS. WINDS
WILL REMAIN GENERALLY SE, WITH SPEEDS INCREASING A BIT FROM LATE
MORNING ONWARD.
KMSP...OPTED TO MAINTAIN A DRY TAF BUT THERE IS A NON-ZERO
CHANCE THAT A FEW SHOWERS COULD REACH MSP THIS AFTERNOON. THE
BETTER CHANCE FOR RAIN COMES JUST BEYOND THIS TAF DURATION SO
BEST TO BE ON THE LOOKOUT FOR THE ADDITION OF PRECIP MENTION IN
LATER ROUTINE TAF ISSUANCES.
/OUTLOOK FOR KMSP/
FRI...MVFR/-SHRA LIKELY. WIND WSW 20-25G30-35 KTS.
SAT...MVFR MRNG CIGS LIKELY. WIND NW 10-15G20-25 KTS.
SUN...VFR. WIND N 10 KTS.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 627 AM CDT WED MAY 14 2025
VFR CONDITIONS EXPECTED THROUGHOUT THIS TAF SET, BUT THERE WILL
BE MID-LEVEL CEILINGS DEVELOPING MAINLY OVER EASTERN MN INTO
WESTERN WI MID-TO-LATE DAY. OTHERWISE, A DECENT CUMULUS FIELD IS
LIKELY ACROSS ALL OF CENTRAL-SOUTHERN MN INTO WESTERN WI. SOME
SCATTERED SHRA/TSRA IS POSSIBLE IN SOUTHWESTERN WI LATE
AFTERNOON, MAINLY IMPACTING EAU AND POSSIBLY RNH, BUT SHOULD
STAY FAR ENOUGH EAST AND NOT IMPACT ANY OTHER TERMINALS.
PRECIPITATION MENTION IS ALSO NOW ADDED IN WESTERN TERMINALS AT
THE TAIL END OF THIS PERIOD AS SHRA/TSRA ADVANCING EAST FROM THE
DAKOTAS WILL IMPACT WESTERN MN PRIOR TO OR AROUND SUNRISE. HAVE
HELD OFF TSRA MENTION TO SEE HOW RADAR TRENDS DEVELOP BUT IT
WOULD NOT BE UNREASONABLE BY ANY MEANS TO HAVE TSRA MOVE IN
INSTEAD OF JUST A RA MENTION. WINDS WILL REMAIN GENERALLY SE,
WITH SPEEDS INCREASING A BIT FROM LATE MORNING ONWARD.
KMSP...ALTHOUGH THE NON-ZERO CHANCE FOR A FEW SHOWERS THIS
AFTERNOON REMAINS, THE BETTER CHANCE FOR PRECIP REACHING MSP
COMES LATER TONIGHT THROUGH THURSDAY MORNING.
/OUTLOOK FOR KMSP/
FRI...MVFR/-SHRA LIKELY. WIND WSW 20-25G30-35 KTS.
SAT...MVFR MRNG CIGS LIKELY. WIND NW 10-15G20-25 KTS.
SUN...VFR. WIND N 10 KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...NONE.
WI...NONE.
DISCUSSION...STRUS
AVIATION...JPC
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