textproduct: Springfield

KEY MESSAGES

- Ongoing showers and thunderstorms will decrease in coverage through the morning. The Flood Watch set to expire at 10 AM this morning.

- 15-30% chance for isolated to scattered showers and thunderstorms this afternoon and evening. Marginal (1 of 5) to Slight (2 of 5) Risk for any storm to be capable of producing damaging wind gusts up to 60-70 mph. Quarter-sized hail is a secondary hazard.

- Additional 30-50% shower and thunderstorm chances Friday. Details on locations, coverage, and hazards are uncertain at this time.

- Heat persists through next week with increasing confidence in multiple days of Heat Index values approaching 100-105.

SHORT TERM /THROUGH TONIGHT/

Issued at 315 AM CDT Thu Aug 6 2026

A widespread shield of rain and thunderstorms is currently spread across central Missouri. While this is occurring along the well-defined nose of a 25-30 kt low-level jet/warm front providing strong warm air advection, the activity is actually pretty messy with no real defined band of heavier precipitation. As a result, rain rates have not particularly achieved flash flooding status for the Flood Watch area in our CWA.

In other synoptic news, the big picture pattern has largely remained unchanged and is forecast to remain unchanged for the short-term forecast. This consists of broad troughing across the northern CONUS with a somewhat stationary front stretching from the OK/TX panhandle, through west/north Missouri, and up into the Great Lakes.

Ongoing showers and thunderstorms diminishing this morning:

There's still a good chunk of time left to see how storms evolve through the morning, especially as the low-level jet is still actively veering from south-southwesterly to southwesterly. As this occurs, thunderstorm activity is then expected to follow suit, shifting slightly southeast into the counties within our Flood Watch. Isolated instances of rain rates up to 1-3 inches are possible, but based on current trends, these look to be quicker in nature with less training, limiting the flooding threat to only very localized areas.

As daytime mixing commences and the low-level jet diminishes, showers and thunderstorms will also decay through the morning.

Some areas to see Heat Index values up to 105 today:

While rain will clear the area, an outflow/differential heating boundary appears to set up from northwest to southeast across central Missouri. This will keep areas cooler in the 80s toward central Missouri. Where clouds will be less plentiful (extreme southwest Missouri and extreme southeast Kansas), temperatures are forecast to rise into the middle to upper 90s with Heat Index values approaching 100-105. There is some uncertainty on the quality of moisture across the area as we get southwesterly mixing winds. The HRRR is an extreme example with dewpoints dropping to the upper 50s (RHs in the 20s to 30s). If this occurs, Heat Index values would stay a bit lower. Either way, expect hot conditions in the far southwest area of our CWA today.

Slight Risk for severe thunderstorms this afternoon and evening:

The southwest mixing winds will actually set the stage for a severe risk this afternoon and evening. The stationary front will continue to hang around the region during the day providing low-level convergence within 2000-4000 J/kg of SBCAPE. The convergence should help pop some storms in this environment, however, HREF sounding plumes suggests some capping of the environment, and if the drier solutions pan out, it may be difficult for many storms to form. Therefore, there is a 15-30% chance for isolated to scattered thunderstorm development along the front this afternoon.

As mentioned, the mixing winds will create steep low-level lapse rates, with the RAP placing 8-9 C/km 0-3 km lapse rates over portions of our area. Additionally, DCAPE values above 1000 J/kg are forecast by the RAP along with elevated microburst parameters. Therefore, damaging downburst wind gusts are possible in any thunderstorm, some potentially significant up to 70 mph. This is driving a Slight (2 of 5) Risk for severe thunderstorms generally south of Highway 54. Storm mode is a tad uncertain as the CAM ensemble spread for deep-layer shear ranges anywhere from 25-35 kts. If shear comes out towards 35 kts, supercells would be possible, bringing a hail risk of up to quarters. Lower shear would promote more multicells and perhaps line segments. Either mode, however, would still support damaging wind gusts as the main hazard.

As for timing, these look to be rather diurnal, developing sometime after 3-4 PM, with the risk lasting until after sunset.

CAM solutions then diverge on what occurs overnight tonight. If you take the HRRR as the all-knowing truth, additional training development is possible. But the reality is that each CAM is its own outlier. Therefore, widespread 30-50% chances of showers and storms are in place for Friday night. There should be some development as WAA overtop the lingering stationary front returns. We'll need to monitor for any additional heavy rainfall or flooding signal.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 315 AM CDT Thu Aug 6 2026

Additional chances for rain Friday, details are uncertain:

Much like the discussion for tonight, there is uncertainty in the location, timing, coverage, and hazards of showers and storms Friday. Since each CAM is its own outlier for storm evolution tonight, each have a different solution Friday. Back to the basics of synoptic meteorology, though, the stationary front continues to hang around, and with instability being no problem, would expect at least isolated shower and thunderstorm development somewhere over our area (30-50% chance).

Heat persists through next week:

The longwave trough axis finally moves east of our region Saturday and Sunday, making way for rising heights and increasing temperatures. Highs over the weekend and into next week are expected to be in the 90s, some areas approaching 100 F. Current dewpoint forecasts keep heat a tad lower than "excessive" with LREF ensembles showing <10% chance for >105 F Heat Index values. However, they do show >60% chances for >100 F values Saturday through at least Tuesday. So, while around 100 F Heat Index is not terribly uncommon for Ozarkian summers, the expected extended nature of 100-105 F Heat Index values introduces a Heat Risk as there will not be much room for heat relief.

While heat will build, the jet stream across the northern CONUS will remain active. Some global models have the enhanced winds dropping south near our northern CWA. This may bring additional chances for rain and storms, but uncertainty in these types of patterns is too high for any appreciable mention above 15% until Wednesday. As an example, the EFI does show values of around 0.8 for CAPE-Shear combo in central and northern Missouri, which may highlight some potential for storms to come careening down the northwest flow of the jet stream sometime next week, but these are always mesoscale matters. Trends will continue to be monitored.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 645 AM CDT Thu Aug 6 2026

A few isolated light showers are currently slowly moving west to east around BBG and SGF. These showers have struggled to drop visibilities below 6SM, and will continue moving east of the area through 15Z. Therefore, no mention in a change in flight category was made in the TAFs for this period.

For much of the period, winds will be 5-10 kts, generally out of the south. With a stationary front meandering around the TAF sites, some variability can be expected, generally between southeasterly and southwesterly.

With the front around the area, additional isolated to scattered showers and thunderstorms are possible (15-30% chance) between 21-04Z. Any storm that does impact the TAF site may be capable of strong downdraft winds up to 50-60 kts.

There is then scenario for additional shower and thunderstorm development between 04-12Z, but the scenario is too low confidence to mention in the TAFs at this time.

Otherwise, multiple cloud levels are expected through the period, with the lowest levels generally staying above 5 kft unless a storm moves through a TAF site.

SGF WATCHES/WARNINGS/ADVISORIES

KS...None. MO...Flood Watch until 10 AM CDT this morning for MOZ055>058- 069>071-083.