West Union, IA Weather

Key Messages

- Cooler temperatures Sunday and Monday before temperatures warm into the 60s and lower 70s by mid-week.

- Precipitation chances (10-40%) Monday and into Tuesday with the bulk of the rainfall staying northwest of the local area.

- Additional rain potential throughout the remainder of the upcoming week.

Discussion

Issued at 158 PM CDT Sat Oct 24 2026

Sunday - Monday: Cooling Down with Some Rain Chances

The general synoptic pattern over the next couple of days keeps zonal flow aloft with a surface cold front passing through the region during the overnight and into Sunday. As a result, temperatures will be noticeably cooler for areas north of I-90 for Sunday in lieu of the previously mentioned cold front. Consequently, the NBM keeps highs in the 50s and 60s for most locations outside of portions of northeast IA and southwest WI where the aforementioned cold front has yet to push through with highs reaching into the 70s. As we head later into the day on Sunday and into Monday, a shortwave trough pushes through the Great Plains with some increasing precipitation potential. Some small rain chances (10-20%) present themselves late Sunday evening and into the overnight as a weak baroclinic zone and low-level frontogenetic axis may instigate some light precipitation as suggested in the CAMs across north-central WI and southeast MN. However, the recent HREF keeps much of the probabilities (10-40%) for measurable precipitation confined to north-central WI and southeast MN on Sunday. As we head into Monday, precipitation chances increase (10-40%) a bit more Monday evening and overnight again for north-central WI and southeast MN as the aforementioned shortwave trough closes in on the region. However, recent guidance has continued to demonstrate a northerly shift with the grand ensemble (GEFS/EC/Canadian ensemble) only having lower-end probabilities (10-40%) for rainfall amounts over 0.05" in north-central WI and southeast MN.

Tuesday - Friday: Cooler But Still Above Normal with Additional Rain Potential

By the time Tuesday rolls around, the aforementioned shortwave impulse pulls northward into Canada with precipitation chances diminishing later into the day on Tuesday. However, right on the heels of the primary shortwave impulse is a secondary shortwave trough that swings through the Northern Plains Tuesday night and into Wednesday bringing additional precipitation chances along with it. Consequently, the grand ensemble (GEFS/EC/Canadian ensemble) has much higher probabilities (60-90%) for measurable rainfall by Wednesday evening and into Thursday morning across the local area. However, given the fairly weak nature of the forcing, probabilities for rainfall amounts over 0.1" are fairly low (10-50%) during this period as well. Additional chances for rainfall will be present into next weekend, however given the low predictability between deterministic and ensemble guidance for how any shortwave impulses may manifest during this timeframe, have lower confidence in precipitation potential for Friday and into next weekend. In any case, not expecting much for impacts with any rainfall throughout the upcoming week.

As far as temperatures are concerned, cooler temperatures in the wake of the aforementioned cold front will give way to a warming trend beginning on Tuesday. This is mostly due to upper-level ridging building back into the region for the latter half of the work week which in turn will allow for temperatures to warm with the NBM having a respectable shot (30-80% chance) for highs to return into the 70s as soon as Wednesday for much of the area south of I- 94. Additionally, with this broader upper-level ridging and zonal flow in place, really not expecting this air mass to change much into next weekend which is suggest in high temperatures fields in the NBM. Therefore, it seems fairly reasonable to conclude that we will trend warmer than normal into Halloween.

Aviation

Issued at 1148 AM CDT Sat Oct 24 2026

VFR conditions are expected throughout the TAF period with winds at 10-15 kts with gusts up to around 25 kts to begin the TAF period. Winds will slowly diminish ahead of a cold front later this evening and switch to the northwest overnight. Sky cover will increase with the frontal passage, however this will likely remain VFR through 12z Sunday.

Arx Watches

WI...None. MN...None. IA...None.