Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/25/21

Area Forecast Discussion
National Weather Service La Crosse WI
528 PM CST Wed Nov 24 2021 .SHORT TERM...(This evening through Thursday) Issued at 130 PM CST Wed Nov 24 2021 A cold front completes its sweep across the region this evening with polar air streaming in overnight and setting the stage for a relatively chilly Thanksgiving day. As of 2pm, a well-advertised cold front was knocking on La Crosse`s doorstep and should complete its passage through the Upper Mississippi River Valley by early this evening. Temperatures steadily fall in its wake back into the 30s this evening with lows plummeting into the upper teens west to mid-20s east. With the surface low pressure cell filling over the next 12-18 hours, winds behind the front have only been gusting into the 20-30kt range upstream in northern Minnesota. Thus, have not deviated too far from the NBM deterministic wind speeds for tonight with a leaning towards the HRRR to capture the higher wind gusts. Low-level moisture wrapping around the lower tropospheric low may experience enough synoptic lift ahead of the H500-300 trough to generate light flurries during the overnight hours. However, low- level omega plots show little support within the region of 100-150mb deep moisture plume/low static stability in the BL, thus stuck with flurries versus explicit snow mention. Low clouds linger to start Thanksgiving Day, but drier air scours out the clouds during the morning hours and should result in a sunny, albeit cold afternoon. With the thermal trough over the region during this timeframe, highs will struggle to reach the mid 20s west to low 30s east. Northwesterly winds remain in place through the day, but lessen in the afternoon/evening as a surface ridge approaches from the west. .LONG TERM...(Thursday night through Wednesday) Issued at 130 PM CST Wed Nov 24 2021 After the passage of the mid-week cold front, a high pressure system will settle into the area Friday, warming temperatures slightly. Highs Friday will be in the high 20s to low 30s. Once the ridge moves through the area, a low pressure system will move into the area late Friday night to early Saturday morning. Its associated cold front could bring some light rain/sprinkles (south of I-90) and flurries (north of I-90) to the area Saturday afternoon to Saturday evening. However, due to limited moisture availability from the northwest flow aloft and timing uncertainty between the GFS and European models, kept pops lower. High temps Saturday should be mainly in the 30s, with some areas reaching low 40s. The end of Thanksgiving weekend is expected to be dry with temps again in the high 30s to low 40s. For Monday, GFS and European models suggest a short time of precip in the morning in central Wisconsin. PWATs across the area of about 0.47 inches could help supply that precip, but model certainty is relatively low at this time, so have kept pops out of the forecast for now. Tuesday and Tuesday night look to be dry with highs in the mid 30s to low 40s. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 528 PM CST Wed Nov 24 2021 MVFR ceilings move into the area tonight lasting until tomorrow morning. Skies will clear out well as drier air advects into the region. VFR conditions are then expected through the end of the period. Overnight, there is a possibility for some accompanying snow flurries with the lower ceilings. However, little to no impacts are expected. Northwesterly winds will persist through the TAF period, but the gusts will lessen tomorrow afternoon as a surface ridge builds in from the west. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Skow LONG TERM...Dahl AVIATION...Peters