Mendota Heights, MN Weather

Key Messages

- Multiple chances for rain through next week. Heaviest rainfall amounts expected across western MN Monday and Monday night.

- Following a cooldown early in the period, the forecast is trending warmer later in the week.

Discussion

Issued at 250 AM CDT Sun Oct 25 2026

Early Sunday morning temperatures are running between 10-20 degrees cooler than 24-hours ago following Saturday's cold frontal passage. The front has stalled to the southeast of the forecast area and currently extends from central IA northeast into central WI. Locally, rain showers tied to a slow-moving moisture axis are expanding northeast out of southwestern MN and have reached the Twin Cities Metro. It's taken some time for the light precipitation to expand eastward due to the aforementioned PWAT/mid-level moisture axis serving as the driver of the shower chances (as opposed to the much more progressive surface front). Rain showers are forecast to linger through daybreak, eventually waning with time as the moisture axis slides south and drier air moves in.

Cool and cloudy weather will be the theme to close the weekend, along with additional chances for light rain. Afternoon highs will struggle to warm out of the mid-50s for most locations. An upper-low currently spinning over the Four Corners region is forecast to lift north towards the Upper Midwest today into tomorrow. Mid-level warm advection will increase ahead of this feature, which will support the redevelopment of band of light precipitation across southern MN later this morning. The band is forecast to slowly lift north through the afternoon and evening in association with a northward shifting moisture axis. The highest PoPs are located across western MN, where forecast soundings depict greatest saturation. The upper- low will pivot across the Great Plains tonight, spawning surface low pressure progged to track from central NE into northwestern MN. This will set the stage for a longer duration measurable rainfall event that will cover a good portion of the forecast area on Monday. Guidance illustrates the development of a broad precipitation shield ahead of the surface low, supported by isentropic ascent and PWATs 200%+ of normal. Given the compact nature of this system, the regional swath of heaviest rainfall will be relatively narrow and highly track dependent. Fortunately, there has been little change in the overall placement of this zone across the guidance suite, as deterministic, global ensemble, and machine learning solutions are in fairly solid agreement that the axis of heaviest rainfall (1"- 1.5") will setup across eastern SD into far western MN. Rainfall amounts will lessen to the east of this swath, with corresponding amounts falling to a quarter to half inch or so from Mankato to the Twin Cities. Dry air flowing in from the southeast and displacement from the strongest forcing will limit amounts to a few hundredths across southeastern MN and most of western WI. The widespread rain will bring even cooler temperatures (40s) for Monday's highs. The precipitation shield will lift north of the forecast area by Tuesday morning.

A lull in the rain activity is forecast for much of the daytime hours Tuesday. However, the next shortwave in the active pattern is progged to advance east of the Rockies through the day. Associated surface low is forecast to translate northeast from the Dakotas into southern Canada, which places the Upper Midwest on the warm side of the system. Winds turn southerly on Tuesday and will combine with WAA to support highs climbing back into the mid 60s along and south of I-94 (perhaps near 70 along I-90). A warm front will lift through the region and spawn addition scattered shower chances later Tuesday. A few rumbles of thunder will also be possible. Mostly dry weather returns for Wednesday, though a few showers will be possible across the southeastern portion of the forecast area. Temperatures should remain quite mild in the 60s.

There are two trends to highlight in the medium to extended forecast period (late week into the upcoming weekend): 1) The NBM is running warmer at the end of the work week, which follows the recent upward shift in ensemble guidance likely owing to large scale ridging. Could another 70 degree observation be in the cards for MSP prior to the end of October? Time will tell, but several members of ensemble suite suggest it is plausible on Friday! 2) There is a growing signal for wet weather next weekend across both global ensembles and machine learning counterparts. Unfortunately, the where and when is somewhat hard to decipher, but with western troughing set to follow the warm up, a system producing wet weather across the Upper Midwest is a possibility. The 40-60 PoPs from the NBM on Halloween may look a little spooky, but it is too early to lock into a wet forecast.

Aviation

Issued at 1212 AM CDT Sun Oct 25 2026

A band of light rain showers is slowly moving to the northeast across southwestern MN. The only terminal observing showers currently is RWF, however it's possible that MKT, MSP, and potentially RNH observe a period of light precipitation between now and daybreak. A band of showers is forecast to redevelop across southern MN mid-morning and gradually lift north. Once again, anticipate precipitation rates to be on the lighter side and have generally opted to follow RAP/CAM guidance for onset times. VFR cigs and light northerly winds expected throughout the period. The only exception is at RNH, where a localized deck of MVFR stratus is present at initiation. Forecast soundings suggest the low stratus will lift prior to daybreak.

KMSP...Batch of VFR showers is moving towards the terminal from the southwest. Maintained a tempo for showers through 10z, prior to an anticipated lull in activity. Band of showers is forecast to lift north this afternoon, which has prompted the inclusion of prevailing VFR -SHRA starting at 20z. Cigs remain VFR through the period.

/OUTLOOK FOR KMSP/ MON...-RA/MVFR likely, chc IFR. Wind NE 5-10kts. TUE...Chc A.M. -SHRA/MVFR. Wind SE 10-15kts. WED...Chc A.M. -SHRA/MVFR. Wind SW 10-15kts.

Mpx Watches

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