Andover, IA 52701 Weather

This Hazardous Weather Outlook is for portions of north central Illinois: northwest Illinois: west central Illinois: east central Iowa: northeast Iowa: southeast Iowa and northeast Missouri.

Day one: THIS AFTERNOON AND TONIGHT

Isolated thunderstorms are possible tonight mainly over eastern Iowa. Strong to severe storms are not anticipated with this activity, but lightning will be the main threat.

Days two through seven: SATURDAY THROUGH THURSDAY

The probability for widespread hazardous weather is low.

Spotter information statement

Spotter activation will not be needed today or tonight.

Key messages

- Rain chances look to increase late this evening through tonight (peaking around 40-70% coverage overnight), with isolated thunderstorms possible.

- An active weather pattern early next week will bring rain and breezy conditions to the region, including on Election Day.

Short term

Issued at 129 PM CDT Fri Oct 30 2026

An area of showers and isolated storms that developed along an 850- 700 mb layer theta-e gradient will continue to move eastward early this afternoon, resulting in a largely dry period this afternoon, although some isolated showers will linger. We are expecting showers to ramp up in coverage late this evening into the overnight hours as a mid-level shortwave impulse and slightly enhanced convergence from a subtle southwesterly 850 mb low-level jet builds over the region. With Pwat values progged around 1 to 1.3" per the latest REFS ensemble, accumulating rainfall area-wide appears likely, with 40- 70% coverage.

As we go into the daylight hours Saturday, the main slug of moisture is expected to lift northward, which should help lower shower chances but still can't rule out isolated to scattered showers through the early afternoon (20-50%). As far as the Trick-or-Treat forecast is concerned, conditions look largely dry, save for the isolated light showers, so not a bad idea to at least keep the rain jacket handy. Otherwise, temperatures look to be around the middle 50s along the Highway 20 corridor to the lower 60s across our south, with an east-southeast wind around 5-10 mph. Doesn't look too bad for any outdoor events/Trick-or-Treating on Halloween evening!

Another mid-level shortwave is progged to sweep through the area Saturday night, but chances of precipitation should remain limited due to a lack of robust moisture and instability. Still, could be some isolated showers lingering over the area, with cloud cover hanging around and lows in the upper 40s to lower 50s. Don't forget to "fall back" one hour Saturday night!

Long term

Issued at 129 PM CDT Fri Oct 30 2026

The long term period will start off on a largely dry note Sunday, with more isolated showers lingering over the area as a slow-moving mid-level trough sweeps through the area. Persistent southeasterly flow will help high temperatures warm to the middle to upper 60s.

The main focus for the long-term continues to be on a large system slated to translate through the central CONUS for Monday through Wednesday morning, including Election Day. The culprit for this active period is an amplified upper-level trough and an associated surface low that's progged to translate through the Midwest. GEFS and EC ensemble guidance suggests a tropical moisture connection with this system, drawing some impressive environmental moisture into the area. In fact, the LREF ensemble mean for Pwats are hovering around 1.4 to 1.6" Monday night and Tuesday morning. If these values come to fruition during this time of year, these Pwat values would be well over the daily maximum for Pwats per the SPC sounding climatology for November 3rd. This is also backed up by the NAEFS ensemble climatological percentile values, suggesting these Pwats would be near the maximum of the climatology for early November. With this said, there still remains some uncertainty on the exact track of the surface low, given continued spread of the low tracks per the EC and GEFS ensembles. Where this surface low goes will dictate where the axis of the heaviest rainfall and strongest winds will be. The latest runs of these ensembles are starting to show some better consensus of the low tracks, mainly over western Iowa into Minnesota, indicating our region would be in the warm sector of the system. This would suggest rainy conditions for Election Day, but not as windy as it would be if we were on the backside of the surface low. With that said, winds with this system generally look to be around 20-30 mph, so nothing too impactful. For areas that receive appreciable rainfall, this could make for some gloomy weather conditions on Election Day. In terms of rainfall amounts, there appears to be a consistent signal, but due to the uncertain low track, the location of the axis of rainfall remains uncertain. However, the latest NBM exceedance probabilities of 1" of total rain or more during this entire period is around 60-90% for most locations, with 2" probabilities around 20-60%. Both of these are maximized over eastern Iowa.

Aviation

Issued at 604 PM CDT Fri Oct 30 2026

Predominantly VFR conditions will be seen through the period. Low VFR cigs with a few showers will be possible near BRL prior to 03z.31. MVFR clouds just west of CID in central IA are progged to lift north this evening, but will continue to monitor trends and amend for brief MVFR cigs if necessary.

Otherwise, a weak shortwave to bring more isolated to scattered showers to portions of eastern IA and northwest IL late tonight/early Saturday. Some brief MVFR cigs/vsbys in the shower activity is possible, but confidence in location too low for prevailing and instead refined PROB30 timing at the terminals. East-southeasterly winds to prevail through the period remaining under 10kts.

Watches, warnings and advisories

IA: None. IL: None. MO: None.