FXUS63 KARX 071731

AFDARX



Area Forecast Discussion

National Weather Service La Crosse WI

1231 PM CDT Mon Apr 7 2025



.KEY MESSAGES...



- Today and tonight will be the coldest of the upcoming week

  with steadily warming temperatures through the upcoming

  weekend--highs return to the 60s by Saturday.



- A longer period of scattered light rain showers Wednesday into

  Thursday. Impacts look to be low with rainfall amounts <0.10

  to 0.20", highest south of Interstate 90 where amounts could

  be locally higher.



&&



.DISCUSSION...

Issued at 130 AM CDT Mon Apr 7 2025



Upcoming Week Temperature Details



A cold front is moving through the forecast area this morning, 

though with the main upper level trough axis dropping into north-

central Wisconsin and advancing to the SSE, snow showers

struggled to materialize west of this trough and have gone dry 

for the bulk of the area south of I-94 for the rest of the 

night. A look at the latest surface analysis shows a 

temperatures difference of 15-20 degrees across the front from 

La Crosse to northeastern Minnesota. With the frontal passage 

taking place by sunrise, highs today should indeed be roughly 

15-20 degrees cooler than Sunday with a stiff north wind in the 

morning slowly decreasing in the afternoon as the surface 

pressure gradient decreases.



With light winds and very dry air, lows tonight crater into the 

teens to low 20s, coldest in the Wisconsin sand bogs where some of 

the coldest guidance drops lows into the single digits. From thereon 

out, temperatures slow creep upward. The only wild card in the 

temperature forecast revolves around the exact track and thermal 

structure of our midweek system. The NBM interquartile temperature 

spread on Wednesday and Thursday is higher than for Friday and 

Saturday, a sign that temperatures will hinge on the coverage of 

clouds and rainfall. While the going deterministic NBM doesn't show 

this potential, highs for Wednesday and Thursday may be similar and 

need adjusting downward in future updates.



Light Showers Wednesday into Thursday



A negatively-tilted upper tropospheric trough builds southeastward 

from the Canadian Prairies into the north-central CONUS on 

Wednesday. The resultant lower tropospheric lee cyclone is progged 

to pull off the Front Range Tuesday night into early Wednesday, and 

track along the I-80 corridor. Moisture return ahead of this system 

will be limited to the lower troposphere with 700-500-mb moisture 

transport vectors oriented out of the WNW. While mesoscale and 

synoptic forcing will be appreciable, the lack of moisture will be 

the key to limiting rainfall amounts. 



A closer look at the individual deterministic progs shows that any 

areas of strong low-level frontogenesis could lead to localized 

rainfall enhancements in excess of 0.50". Where any such band sets 

up remains of low confidence and have not made any adjustments to 

the going forecast. The trough finally begins shifting to the east 

Thursday evening and takes the rainfall threat with it.  The 

forecast is dry on either side of this period through the start of 

the weekend.



&&



.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...

Issued at 1227 PM CDT Mon Apr 7 2025



VFR conditions should prevail over the next 24 hours. Broken

stratocumulus are present east of the Mississippi River and will

be for much of the afternoon, with ceilings remaining mainly in

the 35-45 kft range. A stray flurry or two could occur there as

well, with the chance for this increasing as one goes east, in

any case chance is too low (10%) for a mention at LSE. 

Otherwise, winds out of the north with gusts to 20-25 knots are 

expected this afternoon before light and variable winds occur 

overnight and light southwesterly winds set up during the day 

Tuesday.



&&



.ARX WATCHES/WARNINGS/ADVISORIES...WI...None.

MN...None.

IA...None.



&&



$$



DISCUSSION...Skow

AVIATION...Ferguson