628 

FXUS63 KARX 301718

AFDARX



Area Forecast Discussion

National Weather Service La Crosse WI

1118 AM CST Tue Dec 30 2025



.KEY MESSAGES...



- Potential for light snow today (40-80%) and again Wednesday 

  (30-70%). Total snow accumulations generally around 1 inch or 

  less are expected. Patchy freezing drizzle may develop 

  (10-20%) behind the snowfall this afternoon/evening. 



- Cold air moves in Wednesday night through Friday, resulting in

  a cold start to the new year. New Year's Day will be the

  coldest as morning wind chills 10 to 25 degrees below zero and

  highs topping out in the teens are expected.



&&



.DISCUSSION...

Issued at 352 AM CST Tue Dec 30 2025



Snow Potential Today and Wednesday



Two quick hitting systems move through the Upper Mississippi 

River Valley today and Wednesday, allowing for periods of light

snowfall between the two days. 



Today's system moves into the region by the late morning, 

bringing light snowfall through the afternoon and evening hours 

(40-80%) associated with a wing of 850hPa warm air advection and

broad QG forcing. Snowfall rates should be light, with the 

30.00z HREF suggesting up to 1/4" per hour across our area while 

amounts around 1 inch or less are expected, highest along and 

east of the Mississippi River. 



Low potential (10-20%) exists for a few hours of patchy 

freezing drizzle in the wake of the snowfall this afternoon and

evening as model soundings depict drying within and above the 

DGZ, while saturation remains in the lowest ~6kft, above -10C. 

The main question is if adequate forcing remains present when 

said ice loss occurs to allow drizzle to develop. The 30.03z RAP

suggests the primary warm advection wing shifts eastward by the

time ice loss occurs, limiting the overall forcing expected and

thus drizzle potential. However, some lingering weak warm 

advection along with the passage of a weak low level trough  

could prove to be enough to support this freezing drizzle 

scenario. Regardless, expect slippery spots on the roadways 

during the evening commute via snowfall and/or freezing drizzle.



For Wednesday, an upper level shortwave trough and associated positive

vorticity advection is depicted over the Great Lakes region, 

resulting in far weaker synoptic scale forcing across our area 

as compared to today. However, 800-700hPa frontogenesis is 

expected to develop across the Upper Mississippi River Valley 

associated with a weak cold front moving southward, which will 

support additional light snowfall during the afternoon hours 

(30-70%). Accumulations are expected to be less than 1 inch, 

with the 30.00z LREF suggesting probabilities for greater than 

0.5 inches are 20-40%.



Colder Temperatures For The New Year



Temperatures fall quickly New Year's Eve into New Year's Day in

the wake of the aforementioned cold front, resulting in 

overnight lows in the single digits above and below zero. 

Fortunately, the low level wind field is expected to be on the 

decrease during this time as a low level ridge builds into the 

region, limiting the extent wind chills can fall. This is 

supported by a decreasing trend in LREF probabilities for wind 

chills less than -25 degrees. However, wind chills New Year's 

Eve into the morning of New Year's Day are still expected to be 

cold, generally 10 to 25 degrees below zero despite the 

weakening wind field, so ensure you are prepared if you have 

plans outdoors. 



Upper level ridging continues building across the United States to 

finish out the week, supporting surface high pressure. These 

features are currently expected to shift eastward through the 

weekend, allowing for warming temperatures and minimal threat of 

impactful weather, although will need to monitor for any shortwaves 

that are able to traverse the mean northwest flow during this period 

as variation exists amongst the various ensemble members.



&&



.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...

Issued at 1118 AM CST Tue Dec 30 2025



A tricky aviation forecast is in the cards over the next 6-12 hours 

as we monitor a system pushing through Minnesota this afternoon 

towards the local area. Early this afternoon expecting a break from 

precipitation with MVFR to low-VFR cigs expected, the main question 

in this break period will be if any fzdz will be present with a loss 

of cloud saturation and residual lift in place. Have not seen many 

observations suggesting this so have left out of the TAF for now but 

will continue to monitor. Otherwise, this system will move into the 

local area by mid-afternoon with highest probability (40-80% chance 

in the 30.12z HREF) for IFR to LIFR vsby reductions from snow east 

of the Mississippi River. Further west, confidence remains lower for 

IFR vsby reductions and there remains some question if some fzdz 

could occur on the southwest flank of this system where saturation 

aloft is a question, particularly into the evening. Overall, 

confidence for freezing drizzle is on the low side (15-30% chance) 

and would likely be patchy in nature. Low-MVFR to IFR cigs are 

expected to remain in place overnight with a secondary clipper 

moving into the region towards daybreak on Wednesday bringing MVFR 

to IFR vsby reductions. 



&&



.ARX WATCHES/WARNINGS/ADVISORIES...

WI...None.

MN...None.

IA...None.



&&



$$



DISCUSSION...Falkinham

AVIATION...Naylor