textproduct: La Crosse

KEY MESSAGES

- Light snow is expected along and north of Interstate 90 into late this evening. When combined with the strong gusts expected in southeast Minnesota, visibility may drop to as low as 1/2 mile as snow falls. A Winter Weather Advisory is in effect for portions of southeast Minnesota.

- Critical fire weather conditions ongoing in northeast Iowa with elevated conditions in far southwest Wisconsin. A Red Flag Warning is in effect for northeast Iowa.

- Narrow band of increased (1"+) snowfall rates increase heavy snow potential Thursday night into Friday morning. While limited spatial extent of snowfall inhibits overall confidence in impacts, confidence for 5" of snowfall reaches 50% in spots early Friday morning with 70% probabilities for 40 mph 10 m wind gusts suggest winter weather impacts are likely.

DISCUSSION

Issued at 158 PM CST Wed Feb 18 2026

This afternoon into this evening: light snow and reduced visibility north of I-90, strong winds and dry in northeast Iowa and far southwest Wisconsin:

19z WV satellite shows a strong upper wave over central MN with a belt of moist advection wrapping around this feature over southeast Minnesota into west central Wisconsin. Just to the south of this, notably dry air is seen as evidenced by low and mid level WV channels and surface obs, where RH values under 20 percent are seen in parts of central IA just to our southwest.

Under the belt of moist advection, multiple sites across MN are reporting snow with several in west central MN under a quarter mile. This snow has begun shifting into SE MN as the low levels saturate. With the ARX VWP detecting 55-60 knot west-southwesterly winds at 700mb, winds at the surface have been increasing as well with gusts of 30-40 mph ongoing across SE MN eastward along the I-90 corridor. Primary concern with the snow as it spreads eastward is, despite the likelihood (60-90%) that amounts remain under 3", that visibility drops enough for hazardous conditions to develop. Obs down to 1 mile have occurred at RST/9MN/OWA while they have largely remained a bit higher just to the south at AUM/FKA/ONA. With this largely in line 18.12z HREF visibility probabilities, have maintained ongoing Winter Weather Advisory where said probabilities suggest conditions will likely (60-80%) continue to drop to around 1 mile.

To the south under the dry air, expect efficient mixing to bring the dry conditions to the surface, leading to RH values falling under 20 percent in our CWA, primarily along and south of a parallel defined by the MN/IA border, which remains cloud free as of 19z.

Initial Precipitation Timing & Type Thursday:

Initial band of precipitation Thursday afternoon is expected to remain liquid while progressing northeast within lobes of outgoing low level frontogenesis over above freezing temperatures area wide albeit the northwest-southeast oriented temperature gradient from the low 30s to mid 40s across the forecast area. An entrained filament of dry low level air will inhibit initial precipitation through Thursday morning as waves of low level frontogenesis attempt to overcome the drier air surrounded by more saturated airmass above and below. Enhancement of the deformation zone as the cyclone pair entangles, moistens and eventually saturates, the column through Thursday afternoon/evening.

Heaviest Snowfall Late Thursday Night Into Early Friday Morning:

Subsequent meso-beta north-northeast to south-southwest enhanced frontogenesis co-located with a slight zonal advection of snow supporting high resolution model soundings late Thursday night into early Friday morning raise concern for 1" per hour snowfall rates. While overall residence time of this enhanced band appears relatively transient, the strong forcing /near/ the surface freezing dendritic growth zone could warrant winter storm warning criteria. Corresponding HREF (18.12Z) confidence for 5"+ of snowfall pushes 50% in spots from northeast Iowa through southeast Minnesota into western and central Wisconsin. Combined with 60-70% (HREF 18.12Z) probabilities for 40 mph wind gusts, winter impacts outside of storm total accumulation could be hazardous.

While confidence (50%+) for warning impacts would support watch issuance this afternoon, current ongoing Winter Advisories, Red Flag Warnings, and Wind Advisories with confidence waning on exact location, resulted in collaboration of leaving potential watch or headline issuance for subsequent forecast period(s).

More Seasonable Temperatures & Lingering Precipitation This Weekend:

While overall confidence in the pattern wanes through Friday, the colder low level airmass is expected to reintroduce more seasonable temperatures with daytime highs in the 20s to low 30s through the weekend. Single digit apparent temperatures expected nightly. The upper level low lingers over the Great Lakes through the weekend, perpetuating precipitation chances in Wisconsin in the early weekend.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 545 PM CST Wed Feb 18 2026

Wide range of conditions across the area, with CIGs and visibilities ranging from VFR south of the I-90 corridor to IFR along and north of the I-90 corridor. Areas of snow and potentially blowing snow will continue early this evening as winds start to slowly taper off. Light to moderate snow will start to drift north of the terminals through the overnight hours, largely ending between 06-09Z. A bit of a complex CIG forecast with this package as both terminals sit on the outer edge of the cloud deck. The terminals, especially KRST, could wobble between scattered VFR to broken MVFR for much of the overnight hours before KRST drops to IFR around daybreak. KLSE could see a couple hours of MVFR CIGs tomorrow morning as the low pivots across the area before returning to VFR for the afternoon.

As previously mentioned, wind gusts are expected to taper off through the evening with sustained speeds also on a downward trend to between 5 to 12 kts. By late in the period tomorrow afternoon, winds will begin to pivot to a more north/northeasterly direction and pick up slightly, especially west of the river. Sustained speeds should remain under 15 kts.

FIRE WEATHER

Issued at 158 PM CST Wed Feb 18 2026

Critical fire weather conditions are ongoing this afternoon across northeast Iowa, where winds of 30-35 mph with gusts to 55 mph are ongoing this afternoon. Very dry conditions are seen aloft on low and mid level WV satellite channels and efficient mixing has brought this dry air to the surface with RH values down to around 20 percent in our forecast area and as low as 16 percent in the Waterloo IA area. The Red Flag Warning continues accordingly. The good news is that no major wind shifts are foreseen and consistent west-southwesterly direction should persist through sunset, after which winds will reduce in speed and, after midnight, turn clockwise to out of the northwest.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Wind Advisory until 6 PM CST this evening for WIZ054-061. MN...Wind Advisory until 6 PM CST this evening for MNZ086-087-094- 095. Winter Weather Advisory until 9 PM CST this evening for MNZ079- 086-087. IA...Wind Advisory until 6 PM CST this evening for IAZ008>011-018- 019-029-030. Red Flag Warning until 7 PM CST this evening for IAZ008>011- 018-019-029-030.