textproduct: Springfield

KEY MESSAGES

- 30-50% chance of thunderstorms southeast of I-44 this afternoon. Storms could start as early as 12 PM, and last as late as 10PM, with the most likely timeframe being 3-8 PM.

- Marginal (1 of 5) to Slight (2 of 5) Risk for severe weather with damaging wind gusts up to 60-70 mph as the main threat. Quarter-sized hail also possible. The Slight Risk is confined to south of Highway 60 and east of Highway 65. - Temperatures climb this weekend into early next week with high temperature around 100F and heat index values of 100-105F possible.

SHORT TERM /THROUGH TONIGHT/

Issued at 300 AM CDT Wed Aug 26 2026

As of 2 AM, a weak mid-level shortwave is located right over southwest Missouri as noted in mid-level satellite imagery along with mid-level clouds enshrouding the region. This shortwave is embedded within broad northwesterly flow over the central CONUS, with ridging to the west and modest troughing to the east. Some very light radar echoes have begun showing up ahead of this wave east of Highway 65. Beneath the wave--at the surface--a cold front is in place along the I-44 corridor, just south of Joplin and just north of Springfield. Some very patchy low-level clouds and fog have been intermittently reported along this frontal boundary. This is not expected to be overly widespread as we approach sunrise since the mid-level clouds are keeping temperatures rather mild with Springfield still around 80 F and other areas in the middle to upper 70s.

15-40% chance of showers and thunderstorms early this morning:

Current RAP analysis suggests a weakening cap ahead of the aforementioned shortwave--east of Highway 65--where the current light radar echoes are popping up. Earlier CAMs highlighted this area for potential thunderstorm development as we move through the early morning hours. Curiously, RAP and other model members break out convection despite at least -25 J/kg of inhibition throughout the period. We will have to see if that cap holds out or not. If sufficient erosion of the cap occurs, around 2000 J/kg MUCAPE is present for scattered showers and thunderstorms. Any severe threat with this would be isolated and on the Marginal side with wind gusts up to 60 mph since shear will be on the weaker side (around 25 kts) and the nocturnal inversion will be in place. Brief heavy downpours would be the more prevalent hazard given PWATS at around 1.8 inches.

Any showers or storms that form would only last until 8-10 AM once daytime mixing commences.

30-50% chance of showers and thunderstorms this afternoon:

Attention then turns to the chance for storms this afternoon. The forecast is still pretty messy for a few reasons. Firstly, the evolution of any morning storms could have an effect on storm potential later this afternoon. Some CAMs produce a few clusters out of the activity, which seems to be a more conditional scenario given the capping described above. Nevertheless, if this does occur, this could bring some stabilization to the atmosphere in our CWA, limiting storm potential in the afternoon. Secondly, synoptic support is also a question based on how a remnant MCV in the OK/TX panhandle region evolves (more on that in a moment).

The main certainty in the forecast is the cold front hanging around the I-44 corridor. This front will only move a bit during the day, focusing the chance for isolated to scattered showers and thunderstorms igniting along the boundary, which would be along and southeast of the I-44 corridor after 12 PM this afternoon. With this base level of certainty, any thunderstorm that does develop will carry a Marginal to Slight Risk for damaging winds up to 60-70 mph as both Microburst and Ozarks Pulse Severe Thunderstorm Composites are medium to high, especially in the Slight Risk area confined to south of Highway 60 and east of Highway 65. Hail is generally secondary hazard with these storm types, but with relatively straight 25-30 kt bulk shear profiles characterized by weak low-level shear and storm-relative inflow, paired with strong sub-HGZ CAPE, it wouldn't be farfetched to see a few hailstones up to quarter- sized in any stronger storms.

The alternate scenarios come into play based on how the MCV over the OK/TX panhandle region evolves today. HREF/REFS ensemble means place this MCV somewhere over the MoKsArOk region, which would introduce better lift and shear, ultimately aiding in greater storm coverage and severe hazard potential. The RAP, however, keeps the MCV well to the southwest in the Red River Valley, which would keep better lift and shear away from our area. While HREF/REFS ensemble mean deep-layer shear values are around 30 kts, each member varies on the position of the MCV, which mathematically reduces the shear values. Those members that depict the MCV near our area (75th-90th percentile members) produce deep-layer shear values of 35-40 kts. This level of shear would introduce a mini supercell threat, upping the hail threat to half dollars to golf balls along with the wind threat. This is a more conditional threat, but is certainly a scenario we will have to keep an eye on based on how the MCV tracks.

No matter the scenario, the window for shower and thunderstorms looks to be confined to before 8 PM as the front clears almost all of our area by 7-9 PM.

LONG TERM /THURSDAY THROUGH TUESDAY/

Issued at 300 AM CDT Wed Aug 26 2026

Seasonable temperatures to end the work week:

Following the cold frontal passage, temperatures will cool back to near normal levels for late August standards. Highs will range from the lower 80s toward central MO, to the lower 90s in the far SW MO and SE KS corners. Lows will also be noticeably cooler in the middle 50s to middle 60s.

Abnormal temperatures make a comeback for early September:

Come Saturday, though, the ridge currently over the southwest CONUS is forecast to begin building northeastward into our area, revitalizing southerly flow and subsequent compressional and advection heating. According to NAEFS and ECMWF ESATs, 99.5th percentile 700 mb temperatures will result in above normal temperatures, with the Extreme Forecast Index at values of 0.8-0.9. Highs are forecast to warm into the 90s, and even near 100 F, by early next week. Heat Index values will also rise to 95-105 F, with the greatest values toward the Missouri-Arkansas border. While this level of heat is not crazy for what we've already experienced this August, it is abnormal for early September (as highlighted by the ESATs and EFI). The CPC Heat Index climatology/forecast shows 90th percentile Heat Index values for early September at 95-100 F, with a 70-90% chance to exceed that range sometime in early September. So, since 90th percentile Heat Index values for early September are between 95-100 F, a forecast of 100-105 is certainly closer to the 95th-99th percentile of heat for early September.

With ridging and high pressure in place, rain chances are forecast to be minimal into early next week. That said, global models and NBM rain chances are quite persistent within southwesterly flow just north of our area, so it would not be too out of place to see a few rain chances sneak into the area at some points.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 640 AM CDT Wed Aug 26 2026

A weak frontal boundary in the vicinity of the TAF sites is bringing calm and somewhat variable 3-7 kt winds accompanied by passing high clouds. The front is expected to sag south through the period, bringing north-northeast 8-12 kt winds to SGF and JLN. The front may also trigger a few showers and thunderstorms near SGF (20-30% chance) and BBG (40-50% chance) between 18-00Z. The higher chances at BBG are reflected by the TEMPO in the TAFs. These storms could carry potential hazards of brief heavy downpours, microbursts with gusty surface winds up to 40-50 kts, small hail, and lightning.

After 00Z, winds will calm again to 3-7 kts, but with a dominant direction out of the north-northeast as the front stays to the south.

SGF WATCHES/WARNINGS/ADVISORIES

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