Area Forecast Discussion
Issued by NWS La Crosse, WI
Issued by NWS La Crosse, WI
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844 FXUS63 KARX 110544 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 1144 PM CST Wed Dec 10 2025 .KEY MESSAGES... - Light snow showers and flurries are expected throughout the afternoon. Accumulations will be light, generally only a dusting to a few tenths of an inch, but visibility will likely be reduced in heavier snow. - Next shot at accumulating snowfall comes Thursday afternoon and overnight, generally southwest of a line from Rochester, MN to Rockford, IL. Amounts up to 3 inches are possible (20-40%), highest over northeast Iowa. - Temperatures are on the decrease through the rest of the week, with highs on Saturday and Sunday struggling to climb out of the single digits. Wind chills of -25F to -35F are possible Saturday and Sunday morning. && .DISCUSSION... Issued at 203 PM CST Wed Dec 10 2025 Light Snow Showers and Flurries This Afternoon Through the rest of the afternoon into this evening, flurries to light snow showers are expected as a subtle 700hPa shortwave trough and steepened mid-level lapse rates of 6.5-7.5C/km coinciding with the DGZ continue shifting southeast through the region. The deepest moisture and steepest lapse rates are depicted along and west of the Mississippi River, so confidence in snow is highest over these areas, but can`t rule out some flurries across Wisconsin with forcing from the aforementioned wave combined with low level moisture over the region. Additional accumulations from any snowfall today are expected to be light, generally only a dusting to a few tenths of an inch, but visibility will likley be reduced within snowfall, as low as 1-2 miles in the heaviest showers per observations over central Minnesota earlier today. Potential for snow ends northwest to southeast this evening, fully exiting the region around 9pm, allowing for a dry period tonight through Thursday morning. Accumulating Snowfall Potential Thursday A 700hPa shortwave trough moves southeast into the northern Great Plains Thursday which combined with a band of 850-700hPa frontogenesis associated with the wave should promote a period of accumulating snowfall across the Midwest. Owing to the frontogenetic forcing, a fairly narrow band of snow is expected. Ensemble guidance has been trending the axis of snowfall to the southwest over the past 24 hours, with the 10.12z GEFS/EPS in agreement that this axis develops generally southwest of a line from Rochester, MN to Rockford, IL. 10.00z LREF cluster analysis also indicates a southwest solution is favored but does suggest low potential for northeast shift as roughly 25% of the 10.00z LREF members indicating this outcome owing to some northeast outliers in the 10.06z GEFS/EPS. However, the majority of the members suggest the most probable scenario is the bulk of the accumulating snowfall occurs southwest of our area. Regarding amounts, probabilities have been decreasing across our area, with 10-30% for 3+" depicted in the 10.12z GEFS/EPS assuming a 10:1 ratio. When adjusted for expected snow ratios of 15:1, these probabilities will more likely end up around 20-40%. As this initial wave moves out of the region, another weak shortwave moves through the mean flow Friday morning, leading to additional snowfall potential (30-50%) along and north of I-90. With little available moisture, amounts are expected to be light, generally only a few tenths of an inch. Cold Temperatures This Weekend Ensemble guidance continues to depict very cold temperatures moving into the region this weekend under northwest flow and strong high pressure building into the central United States. The coldest temperatures are favored Saturday morning and Sunday morning when temperatures fall into the single to double digits below zero. There is some variation in the 25th-75th percentile spread of the 10.13z NBM on Saturday owing to uncertainty with cloud coverage, but clearing skies are expected overnight Saturday into Sunday with little variation in the 25th-75th during this period. Apparent temperatures continue to be depicted between -25F and -35F both mornings. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1144 PM CST Wed Dec 10 2025 MVFR CIGS expected through the overnight for most locations. Areas in central Wisconsin will see some clearing taking place early this morning. There remains some uncertainty if the MVFR CIGS linger through the entire forecast period. During the mid morning and the afternoon, cloud coverage may not be BKN or OVC in the MVFR flight category, however clouds ahead of the next chance of snow filter in during the afternoon and evening and gradually decrease in height towards the MVFR flight category. Have decided to add in a SCT deck at KLSE and KRST for this potential. By the time the evening rolls around, MVFR CIGS are likely to occur again. Light snow will be possible for portions of southeast Minnesota and northeast Iowa this afternoon and evening. With the potential that some light snow could fall further north, have left the PROB30 groups for both KLSE and KRST for the late afternoon/early evening. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Falkinham AVIATION...Cecava