485
FXUS63 KARX 061848
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
148 PM CDT WED MAY 6 2026
KEY MESSAGES
- BELOW NORMAL TEMPERATURES FOR THE REMAINDER OF THE WEEK,
WARMING BACK TO AROUND AVERAGE ON SATURDAY.
- THE RISK FOR NEAR FREEZING EARLY MORNING TEMPERATURES
CONTINUES FOR THURSDAY AND FRIDAY, FOCUSED MAINLY EAST OF THE
MISSISSIPPI RIVER.
- A FEW ROUNDS OF LIGHT SHOWERS PEPPER THE AREA THROUGH THE END
OF THE WEEK, BUT THE VAST MAJORITY OF THE FORECAST PERIOD
THROUGH SATURDAY AFTERNOON LOOKS DRY.
DISCUSSION
ISSUED AT 149 PM CDT WED MAY 6 2026
TODAY: QUIET AND COOL
A SUBSTANTIAL CLOUD DECK HAS FORMED ACROSS THE UPPER MIDWEST EARLY
THIS AFTERNOON, KEEPING TEMPERATURES ON THE COOL SIDE IN THE 40S. AS
THIS IS EXPECTED TO PERSIST INTO THE EVENING, HAVE LOWERED HIGH
TEMPERATURES FOR THIS AFTERNOON TO ADJUST FOR THIS TREND. ANY SORT
OF CLEARING WILL HELP TEMPERATURES BRIEFLY RECOVER INTO THE UPPER
40S BUT NOT ANTICIPATING WIDESPREAD 50+ DEGREES ANYMORE. AS A WEAK
SHORTWAVE PASSES THROUGH THE MID-LEVELS JUST TO OUR NORTH, THIS
MIGHT SET OFF SOME SHOWERS LATER THIS AFTERNOON AS IT INTERACTS
WITH MORE ABUNDANT MOISTURE ALOFT AND SOME ELEVATED WEAK
INSTABILITY. A CONTINUED INVERTED-V SIGNATURE ON AREA SOUNDINGS
HIGHLIGHT THE DRY AIR IN THE LOW LEVELS SO MUCH OF THE SHOWER
ACTIVITY MAY NOT EVEN REACH THE GROUND AND PRESENT MORE AS
VIRGA. MOST SHOWERS SHOULD REMAIN TO OUR NORTH ACROSS FAR
NORTHERN WISCONSIN BUT A FEW SPRINKLES WILL BE POSSIBLE FOR SOME
OF OUR NORTH CENTRAL WISCONSIN COUNTIES LATER THIS AFTERNOON.
WHILE THE CLOUD COVER IS EXPECTED TO CONTINUE THROUGH THE AFTERNOON,
THESE ARE EXPECTED TO MIX OUT BY LATER THIS EVENING. HOWEVER,
ANOTHER DECK OF CLOUDS IS EXPECTED TO MOVE IN LATE OVERNIGHT WITH
YET ANOTHER SHORTWAVE IMPULSE PASSING OVERHEAD. THIS CLOUD COVER IS
EXPECTED TO LIMIT THE SEVERITY OF RADIATIONAL COOLING TONIGHT, EVEN
WITH VERY LIGHT WINDS AND A DRY LOW LEVEL AIRMASS IN PLACE. AS
SUCH, HAVE OPTED FOR A FROST ADVISORY FOR WC/SW WISCONSIN, AND
EASTERN PORTIONS OF SE MINNESOTA AND NE IOWA AS THESE AREAS WILL
HAVE A LITTLE MORE TIME TO COOL BEFORE THE CLOUDS MOVE IN. LOW
TEMPERATURES SHOULD BE TEMPERED BY THESE CLOUDS SO MOST AREAS
OUTSIDE OF THE NOTORIOUS COLD DRAINAGE AREAS SHOULD STAY RIGHT
AROUND FREEZING AND NOT DROP INTO THE 20S LIKE LAST NIGHT.
THURSDAY - FRIDAY: WARMER WITH SOME PASSING SHOWERS
AS PREVIOUSLY MENTIONED, ANOTHER SHORTWAVE IMPULSE IS EXPECTED TO
PROPAGATE THROUGH THE NORTHWEST FLOW ALOFT TOMORROW AS THE
WESTERN PERIPHERY OF THE LONGWAVE TROUGH REMAINS OVER THE UPPER
MIDWEST. THIS IS EXPECTED TO PROVIDE A FOCUS FOR SHOWER
DEVELOPMENT EARLY TOMORROW MORNING THROUGH THE AFTERNOON HOURS.
THE MAIN QUESTION CONTINUES TO BE ABOUT THE MID-LEVEL MOISTURE
PLUME EXPECTED WITH THIS PASSAGE. GLOBAL MODELS AND THE GRAND
ENSEMBLE OF THE LREF CONTINUE TO SHOW A MORE WIDESPREAD
FOOTPRINT OF MOISTURE AND OVERALL QPF RETURN. THE HI-RESOLUTION
MODELS HAVE REMAINED LESS ENTHUSED ABOUT THE OVERALL CHANCES
WITH MORE MEAGER MOISTURE RETURN. AS SUCH, NBM PROBABILITIES FOR
MEASURABLE PRECIPITATION HAVE DECREASED TO LESS THAN 20% FOR
AREAS ALONG AND EAST OF THE RIVER. HAVE GENERALLY CONTINUED WITH
THE PREVIOUS FORECAST IN CAPPING POPS AT 20-30% GIVEN THIS LACK
OF CONFIDENCE IN SIGNIFICANT ENOUGH MOISTURE DEPTH TO
EFFECTIVELY OVERCOME THE SUBSTANTIAL DRY AIR AT THE SURFACE. IN
ANY CASE, SHOWERS SHOULD BE VERY LIGHT WITH MINIMAL IMPACTS
EXPECTED.
TEMPERATURE WISE, HIGHS FINALLY START TO CLIMB OUT OF THE 50S AND
INTO THE 60S ACROSS THE REGION, MORE SEASONAL FOR THIS TIME OF YEAR.
WILL NEED TO MONITOR THE POTENTIAL FOR YET ANOTHER FROST/FREEZE
HEADLINE FRIDAY MORNING AS SUB-FREEZING TEMPERATURES LOOK
POSSIBLE FOR WC WISCONSIN. CURRENT NBM PROBABILITIES OF SUB
FREEZING LOW TEMPERATURES SIT IN THE 10-30% RANGE BUT THIS JUMPS
SIGNIFICANTLY WHEN LOOKING AT THE LREF GRAND ENSEMBLE (ENS,
GEFS, GEPS) TO 40-80%. THIS WOULD MAINLY BE FOR THE CHIMNEY
REGION BUT SOME LOCATIONS FURTHER SOUTH COULD CERTAINLY GET
CLOSE TO FREEZING, NECESSITATING A FROST ADVISORY. WILL NEED TO
SEE HOW QUICKLY THE UPPER WAVE MOVES THROUGH AND IF/HOW THIS
WILL IMPACT POTENTIAL CLOUD COVER.
THIS WEEKEND - EARLY NEXT WEEK: WARMER TO START, MORE RAIN CHANCES
AS THE DOME OF COLD AIR ALOFT FINALLY GETS SHUNTED TO THE EAST BY
THIS WEEKEND, WE'LL LIKELY SEE OUR WARMEST TEMPERATURE OF THE
FORECAST PERIOD ON SATURDAY. A LOBE OF 850MB THERMAL RIDGING IS
EXPECTED TO WORK ITS WAY INTO THE UPPER MISSISSIPPI VALLEY WITH
SOME LOW LEVEL WARM AIR ADVECTION OUT OF THE WEST/SOUTHWEST.
HIGH TEMPERATURES LOOK TO CLIMB INTO THE UPPER 60S TO LOW 70S
FOR MOST, A PLEASANT REPRIEVE FOR THE 40S TODAY. HOWEVER, THIS
WILL BE SHORT LIVED AS A COLD FRONT EXTENDING FROM A WEAK
SURFACE LOW TO OUR NORTH IN WESTERN ONTARIO WILL START TO PUSH
SOUTHEAST INTO THE REGION. THE LOW LEVEL SOUTHWEST FLOW WILL
ALLOW FOR SOME MOISTURE RETURN, RESULTING IN SOME SLIGHTLY
INCREASED PWATS ACROSS THE AREA (STILL LOW BY SEASONAL STANDARDS
BUT MORE THAN WHAT WE'VE SEEN FOR MUCH OF THIS PAST WEEK).
BECAUSE OF THIS SLIGHT INCREASE IN MOISTURE, SOME LOW CHANCES
FOR SHOWERS AND MAYBE EVEN A FEW THUNDERSTORMS WILL BE POSSIBLE
LATER IN THE DAY ON SATURDAY ALONG AND AHEAD OF THE FRONT.
THERE'S STILL SOME SYNOPTIC UNCERTAINTY IN REGARDS TO THIS
SYSTEM SO WILL LEAVE THE BLENDED SOLUTION WITH SLIGHTLY HIGHER
POPS (30-40%) CONFINED TO SW WISCONSIN AND NE IOWA. THE MORE
TIME AN AREA CAN HAVE FOR MOISTURE RETURN AHEAD OF THE FRONTAL
PASSAGE WILL HELP WITH RAIN CHANCES SO THE TIMING OF THE FRONT
WILL LIKELY PLAY A BIG ROLE IN FORECAST QPF AMOUNTS. THESE
DETAILS WILL BE IRONED OUT OVER THE COMING DAYS.
BEHIND THE FRONT, SKIES WILL CLEAR OUT AS A SURFACE HIGH
PRESSURE DROPS SOUTH OUT OF CANADA. THIS WILL KEEP CONDITIONS
DRY AND TEMPERATURES SEASONAL FOR THE AREA INTO EARLY NEXT WEEK.
IT ISN'T UNTIL TUESDAY NEXT WEEK THAT WE SEE MORE WIDESPREAD
RAIN CHANCES RETURN AS A RIDGE BUILDS OVER THE WESTERN CONUS,
PUTTING OUR REGION UNDER MORE CYCLONIC FLOW ALOFT. THIS WILL
ALSO COINCIDE WITH MORE ROBUST MOISTURE RETURN, ALLOWING FOR
MORE SUBSTANTIAL RAIN CHANCES.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1230 PM CDT WED MAY 6 2026
BKN-OVC SKIES CONTINUE THROUGH THE AFTERNOON HOURS TODAY,
ALTHOUGH THESE CEILINGS REMAIN VFR GIVEN BASES OF 4KFT OR
GREATER. NORTHWEST WINDS ALSO CONTINUE THROUGH THE AFTERNOON
HOURS WITH GUSTS TO 25KT, STRONGEST WEST OF THE MISSISSIPPI
RIVER. WINDS DIMINISH WITH SUNSET, BECOMING LIGHT OVERNIGHT AND
BACKING TO THE SOUTH-SOUTHWEST BEFORE VEERING TO THE NORTHWEST
AGAIN FOR THURSDAY. SOME CLEARING IS EXPECTED OVERNIGHT AHEAD OF
ANOTHER BOUT OF CLOUDS AROUND 5-10KFT THAT MOVES THROUGH THE
REGION LATE TONIGHT INTO THURSDAY MORNING. THURSDAY AFTERNOON
BRINGS SOME POTENTIAL FOR ISOLATED SHOWERS ALONG AND EAST OF THE
MISSISSIPPI RIVER, BUT CONFIDENCE IN SHOWERS IS LOW, WITH THE
06.12Z HREF ONLY PAINTING 10-30% PROBABILITIES FOR MEASURABLE
PRECIPITATION.
ARX WATCHES/WARNINGS/ADVISORIES
WI...FROST ADVISORY FROM 1 AM TO 8 AM CDT THURSDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...FROST ADVISORY FROM 1 AM TO 8 AM CDT THURSDAY FOR MNZ088-095-
096.
IA...FROST ADVISORY FROM 1 AM TO 8 AM CDT THURSDAY FOR IAZ010-011-
029-030.
DISCUSSION...BARENDSE
AVIATION...FALKINHAM
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