textproduct: Springfield

KEY MESSAGES

- Shower and thunderstorm chances (60-90%) this afternoon into Friday. There is a Slight risk (2 of 4) for localized excessive rainfall/flooding today through Friday morning across southeast KS into southwest MO.

- Additional rain chances (40-60%) through Memorial Day weekend with a gradual warming trend.

SHORT TERM /THROUGH FRIDAY/

Issued at 244 PM CDT Thu May 21 2026

We begin the period under southwesterly geostrophic flow aloft ahead of a longwave trough spreading across the Intermountain West. This trough is pivoting from positive to negative tilt around a closed 500mb low in southern Saskatchewan, creating pockets of upward omega and lift ahead of the base of the trough as it ejects into the southern Plains. This upward omega, paired with an area of isentropic ascent from northeast Oklahoma into southwest Missouri where moisture is being to advected into the area by the southwesterly flow, is leading to areas of showers with some embedded areas of thunder across Kansas, Oklahoma, and Missouri early this afternoon.

SPC mesoanalysis indicates an area of uncapped 500-2500 J/kg of SBCAPE has developed from the Ouachitas into southern Missouri as of 2PM local, which is more than models previously progged or are currently initializing with. Model soundings indicate a very tall and skinny CAPE profile, so the additional instability would only really act to increase thunder chances (which were previously widely scattered embedded rumbles) and would help make rainfall rates more efficient within deeper convection. Still not expecting severe weather.

The primary hazard to watch for over the next 24 hours besides scattered lightning/thunder will be heavy rainfall leading to localized areas of flash flooding. 12Z HREF LPMMs continue to suggest highly localized areas of 1-4" of rain in 6 hours will be possible where deep convection can develop. The most likely area to see these pockets of increased heavy rainfall are generally along and west of an arcing line from Lamar through Mount Vernon and Cassville, where WPC continues their Slight (Level 2 of 4) Risk of excessive rainfall. Widespread rainfall amounts in this area are slightly higher, between 0.5-1", compared to areas to the east of I-49, where widespread 0.1-0.5" can be expected with locally higher amounts where stronger storms develop.

Overall timing of showers and storms will be from this afternoon through late tomorrow morning/early tomorrow afternoon, with the most widespread coverage this evening into tonight as the base of the trough lifts through the area, and showers becoming more scattered through the morning hours as the wave exits to the northeast. Highest coverage will be further west into western Missouri/eastern Kansas, away from the influence of decaying mid-level high pressure in northeast Arkansas and into a better moisture space where the atmosphere has already become saturated from showers this morning.

Lowered temperatures a bit today due to the widespread cloud cover, especially in areas further west, with max temps this afternoon expected to be in the low to mid-70s, and temperatures warmest in south-central Missouri where there's been less cloud cover. Friday will look similar with highs in the low to mid-70s again, but warmer temperatures will be to the west instead due to the cloud cover decaying from west to east.

LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/

Issued at 330 PM CDT Thu May 21 2026

Southerly winds aloft will support a gradual warming trend through the weekend and into next week, with highs in the upper 70s to low 80s through the Memorial Day holiday weekend. However, conditions remain damp as several shortwaves move across the area over the weekend and into next week. Saturday morning should see a period of dry weather before 25-60% shower and thunderstorm chances return in the afternoon and continue into Sunday. Sunday's 25-60% chances are primarily for areas along and south of the I-44 corridor, and push east by the evening. Monday's 30-60% chances are also concentrated along and south of I-44. Extent of coverage remains in question, with showers and storms seeming more scattered in nature to match the scattered vorticity maxes emanating from the shortwaves that move through the area. All day washouts are still not expected Sunday, Monday, or Tuesday, with areas north of I-44 potentially staying dry all 3 days. Seasonably humid dew points in the 60s should support enough instability for some rumbles of thunder each day, but no severe weather is expected

Additional rain chances continue each day through next week, with another trough pushing into the West Coast early next week. Broad rainfall chances spread across the eastern 2/3 of the CONUS by Wednesday, when ensemble solutions begin to diverge.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 636 PM CDT Thu May 21 2026

Scattered rain showers will occur through this evening and into Friday. Visibilities may get near 1 or 2 SM in the heavier bands of rain. Skies will remain overcast and ceilings will hover between MVFR and IFR. There may be a few rumbles of thunder with this activity, but no severe weather is expected.

SGF WATCHES/WARNINGS/ADVISORIES

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