Grain Valley, MO Weather

Key Messages

- Seasonally warm temperatures continue through the weekend and early next week. Broader cool down through the week.

- Widespread precipitation chances difficult to come by until at least the middle of next week.

- Far far NW Missouri / NE Kansas may see chances (10-25 percent) Monday afternoon and evening.

Discussion

Issued at 307 AM CDT Fri Oct 23 2026

There really just is not much sensible weather, at least changes, to speak of. Fortunately, that tends to mean pleasant overall conditions across the area...

The large scale mid-upper level pattern has a good amount of activity within it over the coming days, just not likely to affect the immediate area. Currently the pattern is highlighted by a trough- ridge-trough pattern across CONUS with the ridge axis just a hair west of the Missouri. The western CONUS trough remains expected to split with a piece riding inland and NE around the stout ridge and another piece digging into southern California and becoming a cutoff low. The aforementioned northeastward moving piece will yield a developing surface low and attendant cold front by Saturday, but its rapid movement into Canada leaves little support for the front to push much across the Central Plains. This too is bolstered by the lagging cutoff low beginning to move further inland, preventing any trailing surface high support to develop. With broad surface high pressure remaining over the eastern CONUS, all of this is to say that dry conditions and southerly winds remain through the weekend. With little change in mixing depth, wind speeds, or 925-850mb temps, expect highs to be quite similar to yesterday... mid to upper 70s for most and a few touching 80. Of which would be upwards of 10-15+ deg above normal.

To start the work week, confidence in the broad pattern evolution remains high within GEFS/ECMWF ENS. This can be gleaned a few ways, including within temp spreads. Both ensemble systems tend to suggest 25th/75th spreads of ~5 deg F or less, with that strongest within the ECMWF ENS through Tuesday/Wednesday. The existing mid-level ridge will continue to keep conditions on the dry side as it deflects western CONUS cutoff low (becoming an open wave). The more southerly path of this trough will more substantially flatten the ridge and bring about an outside shot at some light precipitation over far W/NW areas of the CWA as early as Monday evening. Given the pre-existing very dry air mass, it would likely take a notable southerly/easterly trend in the trough path to see measurable precipitation chances. Generally expect temperatures to remain above normal but likely a few degrees cooler than the weekend, in the low to mid 70s, with an uptick in cloud cover and slightly cooler 925- 850mb temps.

Deterministic and ensemble guidance both begin to diverge more significantly mid-late week, primarily differing in their handling of a series of northern stream shortwaves and larger troughs/cutoff lows. Difficult to pin down much in the way of confidence in any frontal or precipitation timing. The 'strongest' takeaways over the latter half of the work week would be best chances for cooling temperatures, and increasing precipitation chances.

Aviation

Issued at 100 PM CDT Fri Oct 23 2026

VFR conditions are expected for the duration of the forecast period. South winds around 10-12 knots with gusts up to 15-20 knots possible mainly north of and including STJ. Gusts curtail after sunset.

Eax Watches

MO...None. KS...None.