FXUS63 KARX 191748

AFDARX



Area Forecast Discussion

National Weather Service La Crosse WI

1248 PM CDT Thu Mar 19 2026



.KEY MESSAGES...



- Warmer, more moist airmass raises nightly fog concerns for

  much of the area through late week. 



- Confidence (60%) in anomalous warmth initially reaches the 

  forecast area Friday, increasing (70%) for Saturday.  



- Moderate confidence (50-70%) for light precipitation Saturday

  night through Sunday. Low confidence in exact location or 

  potential for higher amounts (0.1"+).



&&



.DISCUSSION...

Issued at 957 PM CDT Wed Mar 18 2026



Warming Into Early Weekend, Potential Nightly Fog:



Outside of nightly fog, a relatively quiet period of sensible 

weather is expected after ongoing mixed precipitation potential

in central Wisconsin exits east of the local forecast area 

tonight. Main forecast detail will be advection of anomalously 

warm temperatures into the early weekend and subsequent 

potential preciptiation.



The two main phenomena that will have the largest impact on 

sensible weather locally will be the dense, climatologically 

thick snowpack observed and exact location of a relatively 

diffuse baroclinic boundary strewn northwest to southeast west 

of the Upper Mississippi River Valley tonight, flirting 

east/west over the forecast area as meager waves meander along 

it into this weekend. A farther northeast advection of the warm,

moist airmass will increase nightly fog potential and degree of

hottest temperatures into Saturday. 



Confidence In Warmest Temperatures:



While our on doorstep for Thursday, NBM (18.19Z) probabilities for 

the 60 degree isotherm greatly increase (25-75%) initially Friday 

along our western peripheral counties and into southwest Wisconsin. 

Further warming into the weekend ushers in similar probabilities for 

the 70 degree isotherm locally. Although, high Interquartile Spread 

(25th-75th percentile) of 10-15 degrees over southeast Minnesota on 

Friday spreads across the forecast area on Saturday. Again,  amount 

of melting and resultant albedo will be crucial, ultimate factor to 

monitor Thursday and Friday as the baroclinic boundary attempts to 

advect northeast through the forecast area with passing waves. 



Low Confidence In Late Weekend Precipitation:



The synoptic pattern breaks through the end of the weekend, ushering 

in more normal daytime highs in the 40s to 50s through Sunday and 

low confidence in widespread precipitation potential with the 

passing cold frontal boundary Saturday night through Sunday. As potential

cyclogenesis passes near the forecast area, confidence in precipitation

potential (50-70%) agrees between long term global ensembles 

whilst disagreeing within respective ensemble runs. The GEFS 

(18.18Z) increased probabilities for 0.01" of QPF in 24 hours 

compared to previous run (18.12Z), 50-70% along and east of the 

Mississippi River, while the most recent EPS (18.18Z) decreased 

to similar probabilities in most recent run. Interensemble 

confidence for higher amounts (0.1"/24hr) increases northeast 

of the forecast area, lowest (<15%) in most recent EPS (18.18Z).



&&



.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...

Issued at 1248 PM CDT Thu Mar 19 2026



VFR conditions through the afternoon. MVFR to IFR CIGS develop

over north central Wisconsin early this evening and linger

through much of the morning. There is a 20 to 30% chance that 

these lowered CIGS reach the I-90 corridor during the mid

morning hours on Friday. Otherwise expect CIGS to remain around

15kft to 20kft through much of the TAF period. Light southeast

winds transition to northwest winds early Friday morning. 



&&



.ARX WATCHES/WARNINGS/ADVISORIES...

WI...None.

MN...None.

IA...None.



&&



$$



DISCUSSION...JAR

AVIATION...Cecava