646
FXUS63 KARX 081806
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
106 PM CDT WED JUL 8 2026
KEY MESSAGES
- CLUSTERS OF STORMS DEVELOPING OVER SOUTHERN MINNESOTA INTO
WESTERN WISCONSIN ADVANCE SOUTHEAST THIS EVENING. SOME STORMS
MAY BE SEVERE AND PRODUCE LOCALLY HEAVY RAINFALL OF (1-3"),
MAINLY WEST OF THE MISSISSIPPI RIVER.
- QUIETER WEATHER FOR THE REMAINDER OF THE WEEK WITH A 20-30%
CHANCE OF AFTERNOON STORMS FOR THURSDAY.
- COOLER FOR THE END OF THE WEEK WITH WARMTH RETURNING EARLY
NEXT WEEK.
DISCUSSION
ISSUED AT 100 PM CDT WED JUL 8 2026
THIS AFTERNOON: SEVERE WEATHER AND HEAVY RAIN RISK
A CONVECTIVE COMPLEX THAT MOVED THROUGH CENTRAL MINNESOTA
GRADUALLY DECAYED AND SHIFTED NORTHWARD THROUGH THE MORNING
HOURS AS IT RAN INTO A MORE STABLE AIRMASS, WITH THE BACK EDGE
OF THE ANVIL SHIELD SERVING AS THE TRIGGER FOR NEW CONVECTIVE
DEVELOPMENT AROUND NOON AS RETURN SOUTHERLY FLOW STREAMED UP
THROUGH THE SIOUXLAND. THESE CELLS HAVE ALREADY GROWN INTO A
MULTI-CELL COMPLEX WITH ADDITIONAL CELLS DEVELOPING FURTHER
UPSTREAM ALONG I-90. GIVEN THE EARLIER INITIATION TIMEFRAME AND
CONTINUED CONVECTIVE DEBRIS LINGERING OVER THE FORECAST AREA,
CONCERNS AREA SHIFTING MORE TOWARDS A HEAVY RAIN THREAT VS.
SEVERE THREAT WITH THESE STORMS.
THERE LOOKS TO BE A PERIOD BEFORE 00Z WHERE STORMS COULD TRAIN
ALONG THE I-90 CORRIDOR IN SOUTHEASTERN MINNESOTA BEFORE THE
CONVECTIVE COLD POOLS TAKE OVER AND PROPAGATE TO THE SOUTHEAST,
WHICH SHOULD RESULT IN THE CONVECTIVE COMPLEX SAGGING SOUTHWARD
AS WELL. MULTIPLE RUNS OF THE HRRR THROUGH THE DAY HAVE BEEN
FOCUSING THE QPF AXIS OF 1-3 INCHES (WITH SOME PIXELS OF 4-5
INCHES) BETWEEN I-35 AND HIGHWAY 52 IN SOUTHEAST MINNESOTA AND
FAR NORTHEAST IOWA, AN AREA THAT REMAINS SATURATED FROM LAST
WEEK'S DELUGE. GIVEN THESE TRENDS, HAVE ISSUED A FLOOD WATCH FOR
MUCH OF THE AREA WEST OF THE MISSISSIPPI RIVER THROUGH MIDNIGHT
TONIGHT.
THERE SEVERE THREAT REMAINS ON THE TABLE, BUT WILL PROBABLY BE
MORE FOCUSED WEST OF THE MISSISSIPPI RIVER (MAYBE EVEN CLOSER TO
I-35) WHERE THERE WILL BE BETTER RECOVERY OF THE AIRMASS. THERE
IS SOME SOUTHEASTWARD ELONGATION IN THE 1-5-KM HODOGRAPHS THAT
COULD SUPPORT SOME STORMS ORGANIZATION, BUT WITH CELLS ALREADY
GROWING UPSCALE INTO CLUSTERS, SEVERE WEATHER WILL LIKELY BE
FOCUSED IN NARROW CORRIDORS WHERE THE CONVECTIVE COLD POOLS CAN
ORGANIZE. AS THE STORMS BECOME MORE OUTFLOW DOMINANT IN THE
EVENING, THE SEVERE WEATHER THREAT SHOULD WANE.
THURSDAY AFTERNOON: SCATTERED SHOWERS AND STORMS
COOLER AND SLIGHTLY LESS HUMID AIR FILTERS SOUTHWARD ON
THURSDAY IN THE WAKE OF THIS AFTERNOON'S STORMS, BUT VERTICAL
THERMAL PROFILES WILL STILL SUPPORT PULSE CONVECTION DURING THE
AFTERNOON WITH MLCAPE VALUES OF 1500-2000 J/KG AND LITTLE TO NO
INHIBITION. SHEAR PROFILES AND FORCING WILL BE WEAK AND
THEREFORE STORMS WILL STRUGGLE TO ORGANIZE. VERY LOCALIZED HEAVY
RAINFALL OF 1-2 INCHES WOULD BE THE MAIN THREAT WITH THESE
STORMS GIVEN THEIR SLOWER STORM MOTIONS.
COOL END TO THE WEEK, WARMER NEXT WEEK
UPPER LEVEL RIDGING BUILDS IN FOR THE WEEKEND AND INTO EARLY
NEXT WEEK, KEEPING THE THREAT FOR RAINFALL AT BAY WHILE AT THE
SAME TIME PUMPING HEAT NORTHWARD INTO THE NORTHERN CONUS. AT
THIS POINT, THE WARMEST TEMPERATURES ARE PROGGED TO BE MORE OVER
HIGH PLAINS WITH THE UPPER MISSISSIPPI RIVER VALLEY FALLING
UNDER A WEAK EAST TO SOUTHEASTERLY FLOW UNDER OR JUST WEST OF
THE SURFACE HIGH PRESSURE REFLECTION. THIS MAY ACT TO TEMPER
TEMPERATURES AND DEWPOINTS COMPARED TO LOCATIONS FURTHER WEST,
THOUGH TO THE EXACT DEGREE IS LESS CERTAIN. HIGHS ARE STILL
FORECAST TO REACH INTO THE UPPER 80S TO LOW 90S NO MATTER HOW
YOU SLICE THE FORECAST, MAKING IT FEEL SOLIDLY LIKE SUMMER. THE
RIDGE FLATTENS AROUND MIDWEEK, BUT HOW FAST IT AMPLIFIES EARLIER
IN THE WEEK WILL DICTATE WHETHER THIS FLATTENING BRINGS
CONVECTION DOWN INTO OUR REGION OR IF THE STORMS STAY TO THE
NORTH AND WE REMAIN UNDER THE HEAT. THE VARIOUS ENSEMBLES GROUPS
REMAIN IN THEIR RESPECTIVE CAMPS ON HOW THIS WILL UNFOLD WITH
NO CLEAR LEANING ONE WAY OR ANOTHER.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1250 PM CDT WED JUL 8 2026
PRIMARILY VFR CONDITIONS CONTINUE THROUGH THE NEXT FEW HOURS
WITH LIGHT SOUTHWEST WINDS AHEAD OF EXPECTED SHOWERS AND STORMS
THAT MOVE NORTHWEST TO SOUTHEAST ACROSS THE REGION THIS
AFTERNOON INTO TONIGHT, GENERALLY IN THE 20Z TO 09Z TIMEFRAME.
THAT SAID, THERE ARE SOME STORMS HAVE ALREADY DEVELOPED ALONG
I-35 THIS AFTERNOON. THESE STORMS ARE EXPECTED TO BRING HEAVY
RAINFALL LEADING TO MVFR/IFR CEILINGS AND VISIBILITIES. ALSO
CAN'T RULE OUT SOME STRONG GUSTY WINDS AS THEY MOVE THROUGH.
MVFR TO IFR CEILINGS LINGER THROUGH THE OVERNIGHT HOURS BEHIND
THE SHOWERS/STORMS. THERE IS ALSO THE INDICATION THAT PATCHY FOG
COULD DEVELOP ACROSS THE REGION ALONGSIDE THESE LOWER CEILINGS,
BUT ANY FOG THAT DOES DEVELOP SHOULD BURN OFF FAIRLY QUICKLY THROUGH
THE MORNING HOURS. CONFIDENCE IN FOG IMPACTS IS CURRENTLY NOT
HIGH ENOUGH TO INCLUDE AT THE TAF SITES, BUT IS SOMETHING TO
MONITOR OVERNIGHT. WINDS GRADUALLY SHIFT TO THE NORTHWEST
THROUGH THURSDAY MORNING GENERALLY 10KT OR LESS.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR MNZ086>088-094>096.
IA...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR IAZ008>011-018-019.
DISCUSSION...SKOW
AVIATION...FALKINHAM
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