099
FXUS63 KARX 011000
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
500 AM CDT FRI AUG 1 2025
KEY MESSAGES
- WILDFIRE SMOKE IS LIKELY TO PERSIST INTO THE WEEKEND BRINGING
HAZY SKIES, REDUCED VISIBILITIES, AND DECREASED AIR QUALITY.
- DRY CONDITIONS REMAIN THROUGH THE WEEKEND. UNCERTAINTY IN
PRECIPITATION NEXT WEEK REMAINS.
- MILD TEMPERATURES THROUGH THE WEEKEND BEFORE WARMING NEXT
WEEK.
DISCUSSION
ISSUED AT 310 AM CDT FRI AUG 1 2025
PERSISTING SMOKE
HIGH PRESSURE CONTINUES SOUTHWARD TODAY, SETTLING OVER THE
UPPER MISSISSIPPI RIVER VALLEY BY THE AFTERNOON WHERE IT
STAGNATES AS WE HEAD INTO THE WEEKEND. GIVEN THE WEST TO
NORTHWESTERLY FLOW ALOFT USHERING WILDFIRE SMOKE INTO THE REGION
AND BROAD SUBSIDENCE ASSOCIATED WITH THE HIGH, VERTICALLY
INTEGRATED AND NEAR SURFACE SMOKE SHOULD REMAIN INTO THE WEEKEND
BRINGING HAZY SKIES, REDUCED VISIBILITIES, AND UNHEALTHY AIR
QUALITY TO THE REGION. THE STAGNANT UPPER LEVEL AND SURFACE
PATTERN BEGIN TO BREAK DOWN SUNDAY WITH A FLATTENING UPPER
RIDGE AND EASTWARD SHIFTING SURFACE HIGH UNDER MORE ZONAL FLOW.
THIS SHOULD ALLOW FOR IMPROVEMENTS TO THE SMOKEY CONDITIONS
EARLY NEXT WEEK.
DRY CONDITIONS AND PRECIPITATION UNCERTAINTY
UNDER THE UPPER RIDGE AND SURFACE HIGH PRESSURE, DRY CONDITIONS
ARE EXPECTED THROUGH THE WEEKEND. AS THE UPPER LEVEL PATTERN
BEGINS TO BECOME MORE ZONAL EARLY NEXT WEEK, VARIOUS SHORTWAVE
TROUGHS WILL PROPAGATE EASTWARD ACROSS THE UNITED STATES,
ALTHOUGH UNCERTAINTY REMAINS REGARDING THE EVOLUTION OF THESE
SHORTWAVES AND THEIR INFLUENCE ON PRECIPITATION.
THE 31.00Z GEFS AND ENS REMAIN AT ODDS FOR MUCH OF NEXT WEEK
REGARDING TIMING/LOCATION OF PRECIPITATION. WITH THE FIRST OF
SEVERAL SHORTWAVES, THE GEFS CONTINUES TO SUGGEST RAIN COULD
RETURN WEST OF THE MISSISSIPPI RIVER AS EARLY AS MONDAY, BUT HAS
TRENDED WESTWARD WITH ITS PROBABILITIES OVER THE LAST SEVERAL
RUNS. THIS BRINGS IT MORE IN LINE WITH THE ENS AND NBM, BOTH OF
WHICH SUGGEST DRY SOLUTIONS LIKELY DUE TO THE REMAINING
INFLUENCE OF THE DEPARTING HIGH PRESSURE AND FLATTENING RIDGE.
BOTH ENSEMBLES SUGGEST SHOWERS/STORMS ARE POSSIBLE BY THE
MIDDLE OF THE WEEK ASSOCIATED WITH ANOTHER SHORTWAVE, BUT THE
GEFS SUGGESTS HIGHER PRECIPITATION PROBABILITIES WHEREAS THE ENS
IS LESS AMBITIOUS WITH A DRIER SOLUTION. HAVE STUCK WITH THE
NBM PROBABILITIES OF 10-30% DUE TO THESE VARIATIONS.
BETTER AGREEMENT COMES LATE NEXT WEEK AS A STRONGER SHORTWAVE
PROPAGATES INTO THE NORTHERN PLAINS ALONG THE NORTHERN PERIPHERY
OF A RESURGING RIDGE. IT'S CHALLENGING TO PIN DOWN ANY
SPECIFICS THIS FAR OUT, BUT CURRENT PROBABILITIES OF
PRECIPITATION INCREASE TO 20-40%.
MILD THEN WARMING TEMPERATURES
THE COOLER 925HPA TEMPERATURES ASSOCIATED WITH THE HIGH
PRESSURE SINKING SOUTHWARD INTO THE UPPER MIDWEST HAS ALLOWED
FOR MILD SURFACE TEMPERATURES FOR THIS TIME OF YEAR, GENERALLY 5
TO 10 DEGREES BELOW AVERAGE. THESE COOLER TEMPERATURES CONTINUE
THROUGH THE WEEKEND BEFORE THE HIGH PRESSURE SHIFTS EASTWARD,
ALLOWING FOR SOUTHERLY RETURN FLOW OFF THE GULF WHICH WILL USHER
WARM, MOIST AIR INTO THE MIDWEST BY THE MIDDLE OF NEXT WEEK.
THE CURRENT 6-10 DAY TEMPERATURE OUTLOOK INDICATES ABOVE NORMAL
TEMPERATURES ARE FAVORED.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 500 AM CDT THU JUL 31 2025
CIGS: SKC/SCT HIGH LEVEL CLOUDS INTO SATURDAY.
WX/VSBY: SMOKE WILL CONTINUE TO IMPACT THE REGION INTO SAT WITH 4-
6SM VSBYS EXPECTED AT KRST AND KLSE. WITH HIGH PRESSURE OVERHEAD AND
A VERY LIGHT WIND PROFILE IN THE VERTICAL THROUGH 10 KFT, DAYTIME
MIXING WON'T HELP MUCH FROM A VSBY IMPROVEMENT STANDPOINT. MIGHT
TAKE TIL SUN/MON AS THE HIGH PRESSURE SLOWLY EDGES EAST AND A BIT
MORE OF A SOUTHERLY FETCH DEVELOPS.
THAT LIGHT VERTICAL WIND PROFILE WILL ALSO AID IN RIVER VALLEY FOG
DEVELOPMENT THIS MORNING AND AGAIN SAT MORNING. THE DEEPER LAYER MAY
HAVE DEVELOPED TOO LATE IN THE OVERNIGHT TO IMPACT KLSE WITH
FOG/STRATUS OFF THE RIVER - BUT LOOKS MORE FAVORABLE FOR SAT
MORNING. WILL ADD BCFG TO KLSE FOR SAT MORNING TO ALLUDE TO THIS
POTENTIAL.
WINDS: LIGHT/VRB WITH A BIT MORE OF A EAST/SOUTH TURN LATER
TODAY/TONIGHT.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...FALKINHAM
AVIATION...RIECK
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page