textproduct: Springfield

KEY MESSAGES

- A Heat Advisory remains in effect through 8 PM tonight. Highs near 100 with heat index values of 100-105 degrees can be expected. Daily records may continue to be tied or broken. - Rain and storm chances (15-40%) return late tonight, increasing to 40-80% Sunday and lingering into Monday with a cold frontal passage.

- If several factors align properly, strong winds 50-60 mph and large hail up to the size of quarters could be possible Sunday afternoon (Marginal/Level 1 of 5 Risk for severe weather).

- Return to seasonal temperatures behind the cold front by Tuesday, with near-normal temperatures through the work week.

SHORT TERM /THROUGH TONIGHT/

Issued at 230 AM CDT Sat Sep 19 2026

Current Conditions and Synoptic Overview: 00Z upper air analysis depicts broad ridging still firmly in place across most of the country east of the Rockies, while a trough aloft sits across the Great Basin. Weak low pressure is in place from western Iowa/eastern Nebraska extending southwest into western Kansas, and a cold front has become more well- established along this corridor of lowered pressure over the last few hours. This cold front will be the focus for convective development this afternoon and evening across portions of central and northeast Kansas, generally staying to the north and west of our area today.

Heat Continues Today: With the cold front staying north and west of our area today, very little relief is in sight in terms of the heat. Temperatures in the upper 90s continue, with heat indices again between 100 and 105 degrees this afternoon. As such, the Heat Advisory continues through 8 PM tonight. The potential continues for additional temperature records to be broken again today.

Shower/Thunderstorm Chances Today and Tonight: The afternoon pop-up shower and thunderstorm chances are lower today than previous days, with marginal to no instability to work with (<500 J/kg of SBCAPE across most to all of the area this afternoon). The best rain chances (15-40%) come after midnight tonight as the cold front approaches the northwest portions of our area, with a line of storms organized along the front.

Most 00Z CAM reflectivity fields suggest the storm complex(es) will weaken so much by the time they reach the fringes of our area that most, if not all, storms will dissipate as they reach our counties as they lose access to sufficient instability. Additionally, the front does not appear to be particularly quick-moving, with the fastest solution bringing the front as far south as I-44 by 7AM Sunday, and most models suggesting the front is somewhere between our CWA line and I-44. As such, rain chances would not extend south of I-44 tonight regardless of the persistence of existing convection as it moves into our area.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 245 AM CDT Sat Sep 19 2026

Shower and Storm Chances Continue Sunday Into Monday: As the cold front continues pushing through the area from northwest to southeast through the day on Sunday, shower and thunderstorm chances will continue. Moisture will be best furthest to the west even as the front progresses, so the best instability (>1500 J/kg CAPE) will also likely remain in the western portions of our area for storms to tap into. The questions regarding extent of ongoing showers/storms and residual cloud cover Sunday morning does translate into some questions surrounding location and timing of storms, greatest extent of coverage, and just how intense storms could get. Regardless, with temperatures still in the 90s ahead of the front and dew points increasing by 10+ degrees with frontal passage, re-initiation of storms is expected to some degree by the afternoon as a reinforcing vort max from the upper trough pushes across the region. Once storms re-initiate Sunday afternoon, rainfall will likely continue overnight into Monday as the front slowly slides further southeast out of the area.

Vertical wind profiles are generally unimpressive, with upper- level impulses generally restricted to shortwave intrusions along the northern periphery of the ridge that flattens into Ark- La-Tex through the weekend rather than the support of an organized jet streak. However, remnant enhancements from nocturnal low-level jet streak activity may locally enhance shear to 30-40kts as the jet streaks are advected into our area, increasing shear enough that organized cold pools could briefly develop and support severe winds to 60 mph. If shear >40 kts can overlap with areas where MUCAPE >2000 J/kg AND storms form within that overlap, elevated storms would have the potential to produce hail up to quarter to ping pong sized, but this risk appears more conditional at this time. The most likely time period for this overlap would be Sunday afternoon into early evening.

Convection still appears to not be continuous in time or space throughout the day Sunday, with all-day washouts still appearing unlikely; it appears more likely that multiple rounds of strengthening and diminishing showers and storms will occur throughout Sunday and even into Monday. Most areas are expected to see between 0.25-0.75", with low end (10th percentile) amounts of 0-0.1" and high end amounts (90th percentile) of 1.25-2" in most areas (per NBM). Highly localized bullseyes of 2+ inches seem plausible in areas that see strong storms or repeated rounds of rainfall, with 00Z HREF LPMMs further indicating very localized pockets of 2+ inches could occur somewhere. Even so, considering recent drought, soils will be capable of soaking up 2" easily, so flash flooding is not expected with these storms. Highest rainfall totals are still anticipated to align with areas of highest overall moisture north of I-44.

Heat Sunday, But Then It's Done: As the cold front moves through on Sunday, it will finally start cooling things off. However, far southern and eastern portions of our area may not see the front until Sunday night, so depending cloud cover, moisture return, and frontal progression by Sunday morning, temperatures on Sunday may remain in the 90s for a final day in some areas. Due to this uncertainty, opted not to extend the Heat Advisory into Sunday at this time, but it still remains a possibility, depending on how the situation evolves over the next 24 hours.

However, Monday finally brings temperatures back down below 90 degrees, with a temperature gradient ranging from upper 70s in west-central and central Missouri to mid- to upper 80s in south-central Missouri as the frontal influence lingers across the eastern Ozarks. Tuesday has seasonally appropriate temperatures in the mid- to upper 70s areawide, with lows in the 50s. These temperatures look to continue through the work week, with PoPs remaining below 20% through Thursday.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 604 AM CDT Sat Sep 19 2026

VFR conditions expected to prevail through the TAF period, with southwesterly winds gusting up to 20-24kts between 15Z-23Z at KSGF and KJLN. Clouds will begin to increase as the period progresses and a cold front approaches the region from the northwest. Showers and storms will start to approach KJLN and KSGF after 06Z with the front, but decreasing coverage in activity as it moves southeast makes it appear unlikely that precipitation will impact TAF sites before 12Z.

CLIMATE

Issued at 309 AM CDT Fri Sep 18 2026

Record High Temperatures:

September 19: KSGF: 96/1954 KJLN: 99/2024 KUNO: 97/1954 KVIH: 100/1954

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

Record High Minimum Temperatures:

September 19: KSGF: 73/1931 KJLN: 77/2005 KUNO: 71/2018 KVIH: 74/1978

September 20: KSGF: 74/2018 KJLN: 75/1980 KUNO: 74/2018 KVIH: 73/2018

SGF WATCHES/WARNINGS/ADVISORIES

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