textproduct: Springfield

KEY MESSAGES

- A Heat Advisory is in effect through Saturday. Highs near 100 with Heat Index values 100-105 can be expected. Several daily records may be tied or broken. - Isolated showers and storms this afternoon, particularly across the eastern Ozarks and south-central Missouri.

- Cooler conditions with scattered rain chances arrive early next week. Details on the exact extent of the cooldown and location of the highest rain chances remain uncertain at this time.

SHORT TERM /THROUGH FRIDAY/

Issued at 101 PM CDT Thu Sep 17 2026

Synoptic and Mesoscale Overview:

Broad ridging continues to overspread the central and eastern CONUS today, with a quasi-stationary front draped across northern Missouri. Dew points are in the upper 60s to near 70 degrees as temperatures rise into the mid 90s.

Heat Advisory:

The combination of high temps and dew points will once again produce afternoon heat index values between 100-105 degrees today and tomorrow. With consecutive days of 100+ HI, we have maintained the Heat Advisory areawide.

Isolated Storms Today and Tomorrow:

A fairly stagnant environment suggests persistence forecasting will be a reliable method today. That is, isolated to widely scattered convection looks to initiate across portions of southeast and south-central Missouri this afternoon and evening in response to diurnal heating and weak capping (~25 J/kg) within a zone of weak forcing. Steep low-level lapse rates but modest vertical totals suggest a few of the stronger pulse storms will be capable of downburst winds of 50 to 60 mph, but most if not all activity should remain sub-severe. In fact, most CAMs are slightly less bullish in convective initiation today than they were yesterday. Thus, PoPs have been limited to 20-25%.

By Friday, models show some slightly drier air creeping into far southern Missouri. This drier air will confine the PoP footprint to portions of central Missouri. Most areas will remain dry otherwise.

LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/

Issued at 101 PM CDT Thu Sep 17 2026

Higher Rain Chances Late Saturday thru Monday:

Global models depict a broad mid-level shortwave finally translating east through the Plains and into the Midwest Saturday into Sunday. The latest suite of guidance has continued its slower/later trend with the passage of the attendant surface front through Missouri sometime late Saturday night into Sunday. The increased lift and modest shear along this front will aid in convective initiation likely in the form of loosely organized clusters. The best rain chances will be across central Missouri, with decreasing chances as you look south where drier air will be present. Due to the slow nature of the front, rain chances will persist through Monday afternoon, but all day washouts are not expected.

NBM Probabilistic Rainfall (Sat Night thru Mon): >0.10 inch: 50-70% >0.25 inch: 40-60% >1.00 inch: 10-30%

Heat through at Least Saturday:

There is medium to high confidence in continued afternoon heat index values reaching near 100 deg through at least Saturday, hence the Heat Advisory through 8 PM Saturday evening. If the aforementioned cold front really slows down as it passes through Missouri, or if convection/cloud cover is not quite as widespread as global models suggest, then an extension of the advisory may be needed across southern Missouri where temperatures will remain abnormally hot. Confidence is not high enough to make that decision at this point, however.

Cooler Conditions Early Next Week:

There is high confidence that cooler temperatures will arrive next week. What is less certain is exactly how much cooler these temperatures will end up being. Ensembles continue to disagree in just how far the upper-level trough digs and how much the ridge retreats; indeed, NBM temperature interquartile spreads increase to 7-9 degrees by Monday.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 600 PM CDT Thu Sep 17 2026

VFR conditions expected through the TAF period. Scattered clouds with bases 6-8kft will dissipate by 01-02Z. The isolated shower and thunderstorm activity associated with these clouds is not expected to impact TAF sites due to outflow stabilizing the environment around the terminals, but storms will be scattered across the region for the next 1-2 hours. After that, only forecast change of note is more southerly winds gradually shifting in overnight.

CLIMATE

Issued at 326 AM CDT Thu Sep 17 2026

Record High Temperatures:

September 17: KSGF: 96/1953 KJLN: 95/1953 KVIH: 97/1953 KUNO: 97/1953

September 18: KSGF: 95/2019 KJLN: 97/2022 KVIH: 95/1953 KUNO: 96/1972

September 19: KSGF: 96/1954 KJLN: 99/2024 KUNO: 97/1954

September 20: KSGF: 97/1954 KJLN: 99/1954 KVIH: 95/1954 KUNO: 97/1954

September 21: KUNO: 95/1955

Record High Minimum Temperatures:

September 17: KSGF: 73/1978

September 18: KSGF: 74/1931

September 19: KSGF: 73/1931

September 20: KSGF: 74/2018

September 21: KSGF: 73/1931

SGF WATCHES/WARNINGS/ADVISORIES

KS...Heat Advisory until 8 PM CDT Saturday for KSZ073-097-101. MO...Heat Advisory until 8 PM CDT Saturday for MOZ055>058-066>071- 077>083-088>098-101>106.