460
FXUS63 KARX 120548
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1248 AM CDT SAT SEP 12 2026
KEY MESSAGES
- A LINE OF SHOWERS AND ISOLATED THUNDERSTORMS MOVES IN EARLY
THIS MORNING WITH VERY MINIMAL IMPACTS.
- WIDESPREAD RAIN IS LIKELY MONDAY INTO TUESDAY (70 TO 90%) WITH THE
POTENTIAL FOR LOCALIZED FLOODING.
- COOLER, MORE FALL-LIKE, TEMPERATURES ARE FORECAST OVER THE
NEXT WEEK FOR THE UPPER MIDWEST.
DISCUSSION
ISSUED AT 1247 AM CDT SAT SEP 12 2026
TONIGHT THROUGH SUNDAY: RAIN CHANCES AND TRENDING COOLER
A LINE OF SHOWERS AND THUNDERSTORMS HAS FORMED AND IS
CONTINUING TO MOVE EAST ACROSS SOUTHEAST MINNESOTA AND WESTERN
WISCONSIN. THE STORMS SHOULD ENCOUNTER A MORE STABLE
ENVIRONMENT AS THEY MOVE FURTHER EAST SO THE SEVERE STORM THREAT
IS VERY, VERY LOW FOR EARLY THIS MORNING. THE LINE OF SHOWERS
WITH ISOLATED STORMS MAY GROW FURTHER SOUTH AND QUICKLY MOVE
ACROSS THE AREA EARLY THIS MORNING BEFORE DISSIPATING OR MOVING
OFF TO THE EAST NEAR SUNRISE.
QUIET WEATHER IS FORECAST FOR TODAY AS THE NEXT WEATHER SYSTEMS
THAT WILL IMPACT THE REASON BEGIN TO MOVE IN OVER THE PACIFIC
NORTHWEST AND ANOTHER ONE ATTEMPTS TO DIG SOUTH ACROSS THE GREAT
LAKES REGION. ONE MORE DAY OF NEAR AVERAGE HIGH TEMPERATURES IS
FORECAST FOR TODAY, EVEN WITH A WEAK FRONTAL PASSAGE EARLY
SATURDAY MORNING BEHIND THE LINE OF SHOWERS/STORMS. COOLER AIR
WILL FILTER IN ON SUNDAY AS THE BASE OF A H500 TROUGH DIGS SOUTH
TOWARDS THE UPPER MIDWEST AND HIGHS SHOULD BE AROUND 10 DEGREES
COOLER THAN TODAY'S HIGHS. QUICK MOVING SHOWERS AIDED BY WEAK
SYNOPTIC SCALE SUPPORT MAY MOVE OVER PORTIONS OF THE FORECAST
AREA ON SUNDAY. ANY RAIN THAT DOES FALL SHOULD BE FAIRLY LIGHT
WITH RAIN TOTALS OF A QUARTER INCH OR LESS.
MONDAY AND TUESDAY: WIDESPREAD RAIN WITH THE POTENTIAL FOR FLOODING
THE AFOREMENTIONED LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST
WILL EJECT EAST TO NORTHEASTWARD OVER THE NORTHERN ROCKIES TOWARDS
SASKATCHEWAN AND ONTARIO LATE THIS WEEKEND INTO EARLY NEXT WEEK.
THIS FEATURE WILL PROPEL A SURFACE COLD FRONT OVER THE NORTHERN
PLAINS TOWARDS THE GREAT LAKES DURING THIS TIME FRAME. STRONG H700
THETA-E ADVECTION IS DEPICTED BY FORECAST MODELS OUT AHEAD OF THIS
SYSTEM WHICH SHOULD RESULT IN RAIN SHOWERS AND THUNDERSTORM
DEVELOPMENT ON MONDAY INTO TUESDAY. FAVORABLE ATMOSPHERIC PROFILES
ALONG WITH HIGH PWAT VALUES APPROACHING 2 INCHES, AS SHOWN BY
BLENDED ENSEMBLE GUIDANCE, SHOULD LEAD TO MODERATE TO, AT TIMES,
HEAVY RAINFALL. JUST WHERE AND WHEN THE HEAVIEST RAINFALL MAY FALL
CONTINUES TO VARY AND WILL BE DEPENDENT UPON MESOSCALE FACTORS THAT
WILL LIKELY CONTINUE TO CHANGE OVER THE NEXT FEW DAYS. MEAN ENSEMBLE
OUTPUT ALONG WITH AI BASED MODELS ARE TRENDING TOWARDS THE HEAVIEST
RAINFALL FALLING SOUTH OF THE AREA, BUT THERE COULD BE A CORRIDOR OF
SLIGHTLY HIGHER TOTALS (2-3 INCHES) ACROSS PORTIONS OF THE CWA. IF
HEAVIER RAINFALL OCCURS OVER THE AREA WITH THE FEW ROUNDS OF RAIN
THAT ARE POSSIBLE, LOCALIZED FLOODING CONCERNS MAY OCCUR.
A SECONDARY, MORE UNCERTAIN, THREAT MAY ARISE ON MONDAY WITH A
POTENTIAL FOR SEVERE THUNDERSTORMS. THIS THREAT WILL BE HIGHLY
CONDITIONAL AND IS DEPENDENT UPON INSTABILITY BEING ABLE TO BUILD IN
THROUGHOUT THE DAY. WIND SHEAR WILL NOT BE A PROBLEM AS LOW LEVEL
WIND SHEAR VALUES ARE UPWARDS OF 40-50 KTS. TRENDS REGARDING THE
SEVERE STORM THREAT FOR MONDAY WILL NEED TO BE CLOSELY MONITORED
THROUGHOUT THE WEEKEND.
REST OF NEXT WEEK: RAIN CHANCES CONTINUE WITH COOLER TEMPERATURES
THE WEATHER PATTERN OVER THE REGION WILL BE HIGHLY DEPENDENT ON THE
EVOLUTION OF AN UPPER LEVEL TROUGH DIGGING SOUTH ACROSS THE PACIFIC
NORTHWEST IN THE MIDDLE OF NEXT WEEK. ADDITIONAL ROUNDS OF SHOWERS
OR STORMS WILL BE POSSIBLE IN THE MIDDLE OF THE WEEK AS LONG AS MID
LEVEL MOISTURE IS IN PLACE AND THE TROUGH DIGS FAR ENOUGH SOUTH.
FURTHER PUSHES OF COOLER AIR SHOULD CONTINUE TO MOVE OVER THE REGION
IN THIS PATTERN WHICH SHOULD KEEP DAILY TEMPERATURES ON THE COOLER
SIDE FOR THE ENTIRE WORK WEEK.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
ISSUED AT 1247 AM CDT SAT SEP 12 2026
A LINE OF SHOWERS AND STORMS IS CURRENTLY MOVING THROUGH
SOUTHEAST MINNESOTA AND WESTERN WISCONSIN. THIS LINE WILL MAINLY
IMPACT AREAS NORTH OF I-90 AND DISSIPATE AS IT CONTINUES
EASTWARD OVER THE NEXT FEW HOURS. AFTER THIS LINE PASSES, SOME
MVFR CIGS HAVE BEEN OBSERVED FOR BEHIND THE LINE FOR A COUPLE OF
HOURS. THESE MVFR CIGS WILL CONTINUE TO BE POSSIBLE OVER OUR
REGION THROUGH THE EARLY MORNING TO MID-MORNING HOURS AS THIS
LINE PUSHES EAST. VFR CONDITIONS ARE THEN EXPECTED FROM LATE
THIS MORNING THROUGH THE REST OF THE TAF PERIOD. SOUTHWEST
WINDS OF 10 TO 20 KTS CONTINUE THIS MORNING UNTIL A FRONT MOVES
THROUGH AND CAUSES THE WINDS TO SHIFT TO THE NORTHWEST. THE
WINDS COULD BE GUSTY AS THE FRONT PASSES THROUGH RESULTING IN
SOME LOCATIONS APPROACHING 25 MPH, HOWEVER AS THE AFTERNOON
ARRIVES THESE NORTHWEST WINDS WILL GRADUALLY WEAKEN.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...MUSCHA
AVIATION...CECAVA
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