955
FXUS63 KARX 101812
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
110 PM CDT SAT MAY 10 2025
KEY MESSAGES
- ELEVATED FIRE WEATHER CONDITIONS SUNDAY AND MONDAY WITH DRYING
FUELS (GRASSES, SFC LITTER) AND LOW HUMIDITIES - ESPECIALLY IN THE I-
90 CORRIDOR NORTHWARD. AVOID OUTDOOR BURNING.
- ABOVE NORMAL TEMPS THROUGH THE MID PART OF NEXT WEEK - HIGHS IN
80S INTO NEXT THU EXPECTED. COOLER, BUT MORE SEASONABLE AIR RETURNS
NEXT WEEKEND.
- LOW END RAIN CHANCES (20-40%) TUE/WED. HIGHER THREAT FOR
SHOWERS/STORMS MOVE IN THU/FRI AREAWIDE (40-70%).
DISCUSSION
ISSUED AT 110 PM CDT SAT MAY 10 2025
OVERVIEW: UPPER LEVEL RIDGE AXIS SLATED TO SLIDE EAST OUT OF THE
ROCKIES TODAY, SHIFTING ACROSS THE UPPER MISSISSIPPI RIVER VALLEY BY
MONDAY MORNING. TO THE SOUTH, A CUTOFF 500 MB LOW IS WOBBLING AROUND
THE GULF STATES BUT PROGGED TO LIFT NORTHEAST, GRADUALLY WORKING
OVER THE TN/OH RIVER VALLEYS TUE/WED. DESPITE THE PRESENCE OF THE
RIDGE, SPIRALING BITS OF SHORTWAVE ENERGY COULD WORK FAR ENOUGH
NORTH TO BRING RAIN CHANCES TO THE LOCAL AREA. GOOD CONSENSUS NOW IN
THE BULK OF THE GEFS AND EPS MEMBERS TO PUSH THE RIDGE EAST ACROSS
THE NEW ENGLAND STATES THU, ALLOWING FOR A SHORTWAVE TROUGH TO SWING
IN FROM THE NORTHERN PLAINS. HIGHER THREAT FOR SHOWERS/STORMS WILL
ACCOMPANY IT. THE FLOW LOOKS TO BECOME MORE "ACTIVE" AND PROGRESSIVE
AFTER THAT.
TEMPERATURES: VERY ANOMALOUSLY WARM/HOT AIR STILL PROGGED TO STAY
FOCUSED ACROSS THE NORTHERN PLAINS/NORTHERN-WESTERN MN FOR THE START
OF THE NEW WORK WEEK WITH MAXT EFIS STILL HOVERING AROUND 1.0 AND
SOT OF 1+ AT TIMES. THE UPPER LEVEL LOW WILL WORK TO HOLD THAT HIGH
HEAT AT BAY LOCALLY, BUT HIGHS STILL LOOKING TO WARM WELL INTO THE
80S HERE - 10 TO 15 DEGREES ABOVE NORMAL. SOME UPPER 80S NOT OUT OF
THE QUESTION IN VALLEY, SANDY LOCATIONS.
POST THE THURSDAY SHORTWAVE/COLD FRONT, COOLER, MORE SEASONABLE AIR
RETURNS - POTENTIALLY A 20 DEGREE DROP FROM HIGHS THU TO HIGHS ON
FRI.
RAIN CHANCES: AS THE UPPER LEVEL LOW LIFTS NORTHEAST, BANDS OF
SHORTWAVE ENERGY WILL PINWHEEL COUNTERCLOCKWISE AROUND IT, AND COULD
SPIN AS FAR NORTH AS WI. ITS BEEN A SIGNAL IN THE GEFS AND EPS FOR A
FEW DAYS AND HAVE SEEN AN UPTICK IN BOTH MODELS' ENSEMBLE RUNS FOR
RAIN CHANCES. HOW MUCH SATURATION IS AVAILABLE FOR THE LIFT TO WORK
ON IS A BIG QUESTION AND RH FIELDS, SOUNDINGS AND TIME/HEIGHT X-
SECTIONS AREN'T ENTHUSIASTIC. THE GEFS IS MORE AGGRESSIVE WITH ITS
QPF COMPARED TO THE EPS - PAINTING 40-60% CHANCES FOR 1/10" OR MORE
FROM THE MISSISSIPPI RIVER EASTWARD. THE EPS IS GENERALLY 10% OR
LESS. THE MODEL BLEND HAS INCREASED CHANCES THANKS MOSTLY FROM THE
GEFS MEMBERS, BUT STILL HOLDS LOWER END CHANCES (20-40%) - WHICH ARE
STILL REASONABLE IN THIS SETUP. SOME MEAGER INSTABILITY COULD SPARK
A STORM OR TWO IF PRECIPITATION IS REALIZED.
THURSDAY CONTINUES TO PEAK INTEREST IN THE STRONG/SEVERE STORM
POSSIBILITIES. AN UPPER LEVEL SHORTWAVE TROUGH IS PROGGED TO SLIDE
ACROSS THE NORTHERN PLAINS THU, DEVELOPING A NEGATIVE TILT AS IT
DOES. ACCOMPANY NORTH-SOUTH RUNNING SFC COLD FRONT LAYS ACROSS
WESTERN WI BY 00Z FRI IN MOST RECENT GFS AND EC RUNS. UNLIKE EARLY
IN THE WEEK, SATURATION SHOULDN'T BE A CONCERN WITH A PUSH OF 850 MB
MOISTURE TRANSPORT AHEAD OF THE SFC BOUNDARY. THE WARM/MORE MOIST
AIRMASS COULD PUSH MUCAPES UPWARDS OF 1500-2000 J/KG (VIA THE EC).
NOTE - THE GFS IS RAMBUNCTIOUS WITH ITS SFC TDS AT THIS TIME -
PAINTING UPPER 60S TO AROUND 70. THE MODEL BLEND IS 10 DEGREES LESS.
SO CAPE VALUES IN GFS ARE LIKELY OVER INFLATED - POTENTIALLY BY A
LOT. STILL, THE SCENARIO REPRESENTS THE NEXT BEST OPPORTUNITY FOR
WIDESPREAD SHOWERS AND STORMS. DEPENDING ON TIMING, DEVELOPMENT OF
THE SYSTEM - A FEW STORMS COULD BE OF THE STRONG/SEVERE NATURE.
STILL A LONG WAYS OUT...
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1226 PM CDT SAT MAY 10 2025
VFR CONDITIONS AND CLEAR SKIES THROUGH THE TAF PERIOD. LIGHT
NORTHEAST WINDS SHIFT TO SOUTHEAST WINDS THIS EVENING. DURING THE
OVERNIGHT PERIOD, WINDS WILL SHIFT MORE TOWARDS TO THE SOUTH AND BY
SUNDAY MORNING THEY WILL INCREASE IN MAGNITUDE WITH SUSTAINED WINDS
OF 10 TO 20MPH FOR LOCATIONS WEST OF THE MISSISSIPPI RIVER AND 10 TO
15 MPH FOR AREAS EAST OF THE MISSISSIPPI RIVER.
FIRE WEATHER
ISSUED AT 110 PM CDT SAT MAY 10 2025
DRY CONDITIONS PERSIST WHILE SUNNY CONDITIONS WILL CONTINUE TO
PROMOTE AFTERNOON MIXING SUNDAY-MONDAY...FURTHER DRYING THE NEAR
SFC/SFC LAYER. RESULTING MINIMUM AFTERNOON HUMIDITIES RANGE FROM THE
LOWER 20S SUN TO UPPER 20S FOR MON AREAWIDE. WHILE MOST AREAS HAVE
"GREENED UP", FUELS CONTINUE TO DRY AND COULD BECOME CONDUCIVE TO
QUICKLY CATCH/HOLD A FIRE. PORTIONS OF WESTERN-CENTRAL WI ARE
TRENDING THIS WAY. WINDS ARE NOT STRONG THOUGH, MOSTLY HOLDING IN
THE 10 TO 15 MPH RANGE WHERE THE FUELS LOOK TO BE DRIEST.
ELEVATED FIRE CONDITIONS ARE EXPECTED SUNDAY-MONDAY, HIGHLIGHTED IN
THE I-90 CORRIDOR NORTHWARD. FIRE CONDITIONS COULD BECOME CRITICAL
IF MIXING IS STRONGER (DROPPING RHS INTO THE UPPER TEENS) AND/OR
WINDS INCREASE ABOVE THE CURRENT FORECAST. OUTDOOR BURNING SHOULD BE
POSTPONED.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...RIECK
AVIATION.....CECAVA
FIRE WEATHER...RIECK
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