textproduct: La Crosse

KEY MESSAGES

- Rain continues this morning with showers and storms for this evening. Current forecasted rain amounts are between 0.75 and 1.75" for much of the area. Localized higher amounts to 2" are possible (30-40%) with rises on streams and creeks expected.

- Some of the thunderstorms this evening may be severe with the best chance in northeast Iowa and southwest Wisconsin where a slight (level 2 out of 5) risk exists for severe storms to occur. In this area all hazards - damaging wind, hail, and perhaps a tornado - are possible. Most probable timing for any severe weather to occur looks to be in the evening to early overnight hours.

- Snow may occur along and northwest of an Austin MN to Medford WI line Saturday morning.

- After a cool day on Saturday, temperatures warm up into the low to mid 60s for Sunday and Monday.

UPDATE

Issued at 435 AM CST Fri Mar 6 2026

Areas of dense fog have developed across portions of west- central Wisconsin with observations at Mauston and Volk Field, WI displaying visibilities of 1/4 mile at times. As a result, have issued a Dense Fog Advisory for these areas through 9am with the expectation that as rain moves into Adams/Juneau counties that fog will begin to disperse.

Otherwise, forecast remains relatively on track early this morning with rain moving into portions of northeast IA and southeast MN. This will overspread the area over the next couple of hours and persist through early afternoon as indicated by much of the CAMs. The key question will be exactly how much we recover and destabilize during the afternoon prior to the cold front and large scale ascent ahead of it. The CAMs generally agree on developing convection in southwest IA late this afternoon and early evening before quickly pushing it northeast into the area in the 8-9pm window. The question that remains is exactly how far north it gets as there remains the lingering questions on the degree of destabilization this afternoon as ongoing rainfall departs. Regardless, the hazard assessment remains consistent with previous thinking with all hazards, damaging wind, large hail and a tornado or two being possible during the late evening period with highest confidence for any severe being across northeast IA and southwest WI. Convection will likely leave in fairly short order with much of the CAMs pushing the convective line east of the local area by around midnight to 1am.

DISCUSSION

Issued at 1126 PM CST Thu Mar 5 2026

Rain ahead Friday morning and again Friday evening

04z WV satellite shows an upper trough over the Four Corners with southwesterly flow aloft over the CWA. A lead disturbance in this flow is helping to kick off some severe thunderstorms in the TX Panhandle and this will be the focus for showers (100%) and perhaps (10-20%) a rumble of thunder Friday morning. With southerly moist advection ongoing - 06.00z DVN RAOB had a PWAT above the 75th percentile of observed climatology and this should continue to rise overnight - expect some moderate to heavy rain rates with the morning activity. While some light showers may occur during the afternoon due to on going WAA, most areas should see a bit of a break before showers return in the evening with more thunderstorms (30-50%) compared to the morning round. 06.00z HREF/REFS generally indicate around 0.75-1.75" of total precip across both rounds with potential to top 1" focusing on northeast Iowa and southwest Wisconsin with a chance (30-40%) to top 2", mainly in northeast Iowa but also extending into Grant/Crawford Counties in WI. This will cause rises on creeks and streams and, for quick responding basins (i.e. the Kickapoo) that reach above 2", potential for minor flooding.

Severe storm potential Friday evening

In addition to rain concerns, some storms Friday evening may be severe as rapid southwesterly winds aloft and southerly winds at the surface lead to deep shear values approach 50 knots as 06.00z HREF mean MUCAPE values reach 750 J/kg. With the cold temperatures aloft and this amount of shear, should get at least a bit of organized convection with a risk for hail. However, skinny instability profiles suggest that while severe hail (quarter size) is a concern, top end risk with respect to hail size is limited. Indeed, 05.18z HRRR neural network output suggests a less than 5% risk for 2" hail even when increasing the neighborhood used to calculate said probability. Top concern appears to be damaging wind as downdrafts may bring the strong winds aloft - 06.00z HREF mean shows 45-50 knots at 850mb Friday evening - to the surface. Once again, top end risk appears muted, in this case due to needing to break through to a likely stabilized boundary layer. Finally, connected to boundary layer stability, a tornado risk would be present with any surface based storms given progged sfc-500m SRH values, but the risk for this appears to be small (under 5%). In summary, no severe hazards can be ruled out, but hazard looks to focus on damaging wind, hail, and a tornado in that order of relative probability.

Wintry precipitation possible Saturday morning

Snow looks to occur in the northwestern quadrant of the surface low Friday night into Saturday. While this will mainly affect areas to our northwest in central MN, trend in location of the 850/925mb frontogenetic band has slowly approached our northwest. In fact, 06.00z HREF has a 50-75% chance for at least some snow to occur northwest of an Austin MN to Medford WI. On closer inspection of progged vertical profiles, some guidance suggests freezing drizzle may occur as the DGZ may dry out while strong near surface ascent associated with 925mb frontogenesis occurs. Similar to the snow risk, this would focus on areas northwest of Austin to Medford but the DGZ has a better chance to be dry in areas west of the Mississippi while ascent continues in the low levels. Will need to closely monitor this in case trends continue to bring the edge of the snow/freezing drizzle into our CWA.

Temperatures rebound into next week

After a brief cool down in the wake of the cold front Saturday, mostly sunny skies should lead to temperatures returning to the 50s and 60s Sunday and Monday. Next period of precip looks to be Tuesday into Wednesday as a northern stream wave passed over MN/WI. However, moisture looks to be limited as this is out of phase with a southern stream disturbance bringing widespread precip to the lower Mississippi valley and OH Valley during this time period, keeping the southerly moist advection seen early in the period from resuming in our region.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 516 AM CST Fri Mar 6 2026

IFR conditions are expected throughout much of the TAF period as low- level moisture remains in place resulting in IFR cigs. Rain will continue to move through the region this morning dropping vsbys to 1- 4SM at times with an occasional rumble of thunder possible, however confidence was not high enough to mention in either TAF. A brief lull in precipitation will ensue for the afternoon prior to additional showers and storms moving in for the evening at around 02- 04z with high confidence for IFR vsby reductions underneath any storms. Storms will exit after midnight with low-level moisture remaining in place with cigs staying IFR until 12z Saturday. Winds will shift with the passage of a cold front to northwesterly during the overnight hours and into early Saturday morning with winds increasing to around 10-15 kts with gusts up to 25 kts possible prior to daybreak on Saturday.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Dense Fog Advisory until 9 AM CST this morning for WIZ043-044. MN...None. IA...None.