FXUS63 KARX 051853 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 153 PM CDT Sat Jul 5 2025 .KEY MESSAGES... - Scattered showers and storms rest of this afternoon-evening with a low chance (<20%) for any strong to severe storms; localized gusty winds and heavy rain the main threat but can't rule out a funnel cloud - Seasonable summer stretch next week with on/off chances (20-40%) for showers and storms; plenty of dry breaks in between && .DISCUSSION... Issued at 153 PM CDT Sat Jul 5 2025 Rest of today: messy, weakly organized potential for storms A 500mb trough continues to build into the Upper Mississippi Valley today. A embedded shortwave / vort max along its leading edge, in conjunction with favorable low level moisture transport, has sustained a narrow band of showers and isolated storms since last night from Iowa into northern Wisconsin. Despite the moisture transport weakening toward midday, the vort max is now encountering favorable daytime heating as it works into Wisconsin, allowing the activity to expand northeastward. As for convective trends for the rest of today, guidance paints a pretty murky picture overall. The boundary layer west of the Mississippi River, where rain was more prevalent this morning, will likely struggle to recover much until later afternoon. Morning sunshine over portions of western/central Wisconsin allowed for decent but not strong low level lapse rates there and better instability. SPC mesoanalysis and HREF suggest 1000-2000 J/kg CAPE this afternoon, but forecast sounding profiles depict this as tall/skinny, so updraft acceleration will be pretty limited. Add to that paltry deep layer shear, which will prevent storms that do develop from becoming organized, limiting their lifespan. Main threat today will be localized gusty winds, but even that isn't a significant risk as the pool of favorable DCAPE is rapidly retreating eastward. All in all, can't rule out a few stronger storms this afternoon into early evening and perhaps an isolated severe storm. There have also been a couple reports of landspouts/funnels early this afternoon upstream in parts of south-central MN and northwest IA. Conditions are more favorable out that way with weak surface vorticity along a wind shift line and some better low level instability, but can't rule out a small chance (20%) of a funnel cloud or two west of the Mississippi this afternoon. Eventually a weak cold front will drop southeast from MN and northwest WI into this evening. By that time, the atmosphere west of the Mississippi River should recover sufficiently to allow for somewhat of a linear multicell cluster across the area, diminishing and exiting our east by early Sunday morning. Localized heavy rain may accompany some of the stronger storms today-tonight. HREF localized probability-matched mean suggests rainfall amounts through tonight should average around 1/2 inch or less across most of the area. There will likely be pockets of 1.5 to 2+ inches where stronger storms track or repeat over an area. Next week: Seasonable summer stretch with occasional storm chances After a dry Sunday, the upcoming week looks pretty seasonable for early July, without any significant changes in airmass but with typical on and off chances for showers/storms. Flow aloft turns somewhat zonal to start, but a couple embedded shortwaves cut through the region Monday afternoon and again on Tuesday. Then an amplifying ridge out west yields a more northwest flow pattern aloft for our region heading into midweek, and there look to be multiple disturbances in the flow to provide continued on and off rain chances at times through late week. Expecting there will be some dry periods here and there, but for now will let NBM handle it given the wide spread in model guidance and lower predictability signals in that timeframe. For now it holds mostly 20-40% PoPs from Monday night through the end of the week. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1239 PM CDT Sat Jul 5 2025 Scattered showers and storms will continue through the afternoon and into the evening. Lightning will be the main concern with these storms with some potential for strong gusty winds and heavy rain as well. Due to the scattered nature of the these storms, have continued with a TEMPO group for both KLSE and KRST for thunderstorms this afternoon. MVFR CIGS and visibilities have already been observed where these showers and storms occur. These lowered flight categories are expected to continue whenever it is raining. All precipitation chances diminish later this evening. Southwest winds transition to northwest winds between 00Z and 04Z as a cold front shifts southeastward across the area. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Kurz AVIATION...Cecava