Jamestown, MO 65046 Weather

Key messages

- Temperatures remain abnormally-warm through early next week.

- Showers and a few thunderstorms are expected at times through the weekend, mainly this morning and late Saturday into Sunday morning with plenty of dry time otherwise.

- Widespread, beneficial rainfall arrives next week.

Short term

Issued at 329 AM CDT Fri Oct 30 2026

Convection continues to percolate at this hour across northern Missouri into west-central Illinois along a weak, stalled front impinged by an equally-weak low-level jet centered in the Plains. The thunderstorms are stalling where they form, leading to locally- heavy rainfall. A few weaker showers extend south to near the eastern I-70 corridor, but are more isolated and further removed from any forcing. Aloft, weak ridging persists but a longwave evident in mid-level water vapor imagery is crawling north from Mexico into the southern Plains. The presence of the front and resultant cloud cover and intermittent convection will keep temperatures in check across northern Missouri and west-central Illinois today. Further south, another unseasonably-warm and largely dry day is in store. Short-range guidance is in pretty fair agreement that sometime today, likely in the afternoon, flow aloft gradually amplifies and becomes more southwesterly ahead of the slow- moving trough from the southern Plains. This change will result in increased rain chances, mainly west of our forecast area, this afternoon and evening. A few stray showers can't be ruled out across central and northeast Missouri associated with the diffluent flow aloft, but most will stay dry into early Saturday.

By the morning hours of Halloween, weak, broad troughing aloft will be overhead in the Mid-Mississippi Valley, promoting abundant cloud cover that will inhibit temperatures noticeably compared to previous days. Model soundings are quite stable and struggle to saturate the low-levels, keeping a threat for any stronger showers or thunderstorms at bay. Weak, nebulous isentropic ascent is evident in most guidance, suggesting light rain remains a threat for outdoor activities. That said, most solutions suggest that what little ascent exists will maximize late in the evening Saturday. While a completely-dry day is not a guarantee, trick-or-treating won't be a washout by any standards and most areas will be largely dry until the ghosts and goblins are inside for the night.

Long term

Issued at 329 AM CDT Fri Oct 30 2026

As the clocks roll back and the calendar turns forward to November, the light rain associated with this initial weak wave tracks east and exits the region early Sunday afternoon. Meanwhile, a deeply- amplified trough comes onshore across the western CONUS. In between these two waves, weak ridging aloft will promote a dry start to the work week on Monday. The western wave makes quick eastward progress and arrives in the Mid-Mississippi Valley by late Monday night, according to a growing consensus of ensemble guidance. As it tracks east, it will occlude, slow down, and draw copious Gulf moisture poleward. As a result, precipitable water values are forecast above the 99th climatological percentile across much of the region, potentially setting records for early November. The strong forcing and abundant moisture will all but certainly result in widespread, beneficial rain for the region from very late Monday through at least early Thursday. In this timeframe, there is an areawide 20-30% chance for at least 1.00 inches of rain according to the NBM. The highest totals (perhaps as high as 3.00 inches locally) appear to be most likely across western Missouri where forcing and moisture overlap is maximized in ensemble guidance.

Despite these favorable synoptic parameters, model soundings show very limited instability and only marginal warm cloud depths for more efficient rainfall. While I cannot rule out some instances of heavier rain where multiple rounds impact the same place, that should be the exception and not the rule in this event. As for a severe thunderstorm risk, while shear parameters are understandably more impressive with the strong wave, instability remains very limited and jet-level dynamics are very unfavorable for large-scale ascent. These factors greatly limit any strong convection, however if more instability can be made available to this impressive shear and forcing, we would have a much higher severe weather threat. That scenario is currently highly unlikely.

Depending on the speed and structure of this trough, we may see intermittent rain linger through most of the week. By Friday, most depictions of the wave show it east of the region. Unfortunately for those looking for another decided taste of Fall, near to slightly- above normal temperatures stick around in its wake. The airmass that follows our widespread rain, while cooler, is not really Arctic in nature by any stretch. The polar jet remains locked across southern Canada for the foreseeable future, keeping shots of cold air from making any intrusions south. By the end of the week, above-normal temperatures and drier conditions appear favored yet again going into mid-November.

Aviation

Issued at 629 AM CDT Fri Oct 30 2026

Showers and thunderstorms largely evaded the terminals overnight, but KUIN has been under a near-constant threat for convection since midnight. This will continue through the morning as a front lifts north through the region, gradually ending early this afternoon. Fog at KSUS is also rapidly improving and should be all but dissipated by sunrise.

VFR conditions are forecast today, though fog may redevelop in the river valleys tonight. Rain chances increase for Saturday evening, just beyond the current TAF period. Rain intensity will likely be light, making widespread impacts unlikely.

Watches, warnings and advisories

MO: None. IL: None.