791
FXUS63 KARX 180519
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1219 AM CDT SUN OCT 18 2026
KEY MESSAGES
- MOSTLY DRY WEEK WITH GRADUAL WARMING TO SLIGHTLY ABOVE NORMAL
TEMPERATURES BY MIDWEEK. WINDS WEAKEN FOR MONDAY.
- PRECIPITATION CHANCES INCREASE FOR NEXT WEEKEND.
DISCUSSION
ISSUED AT 1219 AM CDT SUN OCT 18 2026
SLIGHTLY LESS BREEZY AND WARMER END TO THE WEEKEND:
WHILE NOT AS STRONG AS SATURDAY, ANOTHER DAY OF BREEZY SOUTHWEST
WINDS WITH GUSTS NEARING 30+ MPH PRIMARILY WEST OF THE MISSISSIPPI
RIVER VALLEY EXPECTED TODAY. UPSTREAM LOW LEVEL TROUGHOLYSIS NEAR
THE MISSOURI RIVER VALLEY THROUGH SUNDAY CAUSES A LOW LEVEL
STRETCHING AXIS TO EVENTUALLY SUCCUMB TO ANTICYCLONIC FLOW THROUGH
THE START OF THE WEEK, RESULTING IN SLIGHTLY WARMER TEMPERATURES, A
FEW DEGREES ABOVE NORMAL BY MIDWEEK, AND LIGHTER WINDS THROUGH THE
START OF THE WEEK.
MOSTLY MILD WEEK:
HAVE LOWERED SURFACE DEWPOINT TEMPERATURES A COUPLE OF DEGREES TODAY
BASED ON SATURDAY'S OBSERVATIONS AND RESIDUAL LOW LEVEL DRY AIR.
OTHERWISE, A BAND OF SLIGHTLY INCREASED LOW LEVEL MOISTURE WILL
RESIDE OVER THE FORECAST AREA THROUGH THE NEW WEEK, TIED BETWEEN THE
EXITING UPPER LEVEL LOW OVER HUDSON BAY AND RETURN TROPICAL FLOW
THROUGH SOUTHERN TO CENTRAL PLAINS. MAIN LOCAL IMPACT WILL BE BOUTS
OF INCREASED CLOUD COVER COMPARED TO CURRENTLY FORECASTED NBM DUE TO
POTENTIAL LOW BIAS GIVEN A MAXIMUM 40% THURSDAY OUTSIDE OF A
SPLOTCHY 40-50% FOR MONDAY. WHILE CURRENTLY FORECASTED PRECIPITATION
POTENTIAL REMAINS LESS THAN 10% THROUGH MIDWEEK, RECENT LREF MEMBERS
(GEFS 17.18Z/EPS 17.18Z) HAVE EXHIBITED A 10-20% INCREASE FOR
MEASURABLE PRECIPITATION (0.01") COMPARED TO THEIR RESPECTIVE
PREVIOUS RUNS, NEARING 20-40%/10-30%, RESPECTIVELY WEDNESDAY NIGHT
INTO THURSDAY MORNING. MINIMAL IMPACT REGARDLESS GIVEN OVERALL HIGH
CONFIDENCE IN ABOVE FREEZING SURFACE TEMPERATURES.
WEEKEND PRECIPITATION POTENTIAL:
SUBSEQUENT MORE WIDESPREAD PRECIPITATION CHANCES REACH THE UPPER
MISSISSIPPI RIVER VALLEY THIS WEEKEND AS A QUASI WEAK OMEGA BLOCK
BREAKS DOWN AND MID LEVEL POSITIVE VORTICITY ADVECTION LIFTS
NORTHEAST THROUGH THE CENTRAL CONUS. LREF MEMBER PROBABILITIES
ABSTAIN CERTAIN PROBABILITIES WELL TO THE WEST/NORTHWEST OF THE
FORECAST AREA CLOSER TO THE AREA OF STRONGEST SYNOPTIC FORCING WITH
50% PROBABILITIES FOR 0.01" OF RAINFALL SEEN OVER THE WESTERN HALF
OF THE LOCAL FORECAST AREA.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1219 AM CDT SUN OCT 18 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD WITH SOUTH TO
SOUTHWESTERLY WINDS REMAINING ELEVATED OVERNIGHT AND INTO THE
DAYTIME HOURS TOMORROW. WINDS WILL REMAIN BETWEEN 12-18 KTS WITH
GUSTS UP TO AROUND 25 KTS UNTIL THEY DECREASE LATER INTO THE EVENING
ON SUNDAY. SOME LLWS CANNOT BE RULED OUT AT KLSE TOMORROW
EVENING/NIGHT WITH AN INCREASING LOW-LEVEL WIND FIELD UP TO 40 KTS
IN THE RAP. GIVEN THE ONGOING BREEZY WINDS ACROSS THE REGION,
VALLEY FOG IS EXTREMELY UNLIKELY.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...JAR
AVIATION...NAYLOR
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