textproduct: Springfield

KEY MESSAGES

- Widespread showers and storms will move through the area late this evening into Tuesday morning. Coverage of severe storms is expected to be low, but any stronger embedded storms may produce wind gusts up to 60 mph and hail up to quarter to golf ball size. - Narrow window for lingering Marginal to Slight severe risk across south-central Missouri Tuesday afternoon. Specific hazard probabilities will depend on cold front speed, but all hazards will be possible.

- Below average temperatures Wednesday into Thursday, with a warming trend to average temperatures by the weekend. Weekend precipitation possible with a frontal passage Saturday.

SHORT TERM /THROUGH TUESDAY/

Issued at 300 PM CDT Mon May 4 2026

Current RAP analysis shows broad west-northwesterly flow with mid-level water vapor imagery depicting several plumes of Pacific moisture within the flow, moving into the central Plains. Upper air analyses put Missouri in between broad, low amplitude ridging to the southwest, and broad, low amplitude troughing to the north. The troughing to the north is forcing an occluded surface low south of the Hudson Bay, with an attending cold front stretching down through Iowa and Nebraska. While there is ridging above 500 mb to the southwest, 700 mb RAP analyses depict a shortwave over the NM/TX border that is forcing a surface pressure trough and diffuse dryline over west TX/OK. The 700 mb shortwave is also producing 850-700 mb warm air advection over OK, which will slowly move into our area tonight as the shortwave progresses eastward. The cold front and 700 mb shortwave will both be our weather-makers in the short- term, bringing widespread showers and thunderstorms (70-90% chance) along with a threat for isolated embedded strong to severe thunderstorms.

Widespread storms tonight, potential for embedded severe storms:

The two features mentioned above will seemingly collide right over our area this evening and through tonight. The first area could bring a broken line of thunderstorms from central MO down south into our area along the cold front. Many CAMs have this activity fizzling out as it enters our area late this evening, as deep-layer shear decreases to 25-35 kts. Though with lingering MUCAPE around 750-1000 J/kg, any lingering activity could be conducive for hail up to quarters as the primary threat and damaging winds up to 60 mph as a secondary threat. These storms would enter the Hwy 54 corridor between 11 PM and 4 AM timeframe.

The second area occurs with the elevated warm air advection nose ahead of the approaching 700 mb shortwave. All CAMs are in agreement with a band of convection developing at the lead edge of the WAA where elevated instability will also be around 750-1500 J/kg with deep-layer shear increasing to a more notable 30-45 kts. While 1-6 km shear will be greater, mid-level flow in the 2-5 km layer will be rather similar, decreasing overall shear. Therefore, storms along this band are expected to be more messy and conglomerate into widespread showers and storms (aided by the added lift from the southward dropping cold front). However, given the environment in place, any stronger embedded storm will be capable of producing hail up to quarters. If a supercell can develop and be maintained in the mess-fest (which instability/shear will be just sufficient for), hail up to golf balls to limes will be possible as instability will be focused around the hail-growth zone with strong storm- relative inflow, mid-level lapse rates at 8-9 C/km, and a large hail parameter of 8-10 (research supportive of lime size hail +/- 0.5 inches).

While any storms will be capable of small hail (less than quarters) anywhere and throughout the night, the greatest larger hail threat would be along/west of Highway 65, and especially along and west of I-49, since MUCAPE drops off significantly as you approach the Highway 65 corridor. This band of storms would enter the I-49 corridor and westward by 11 PM to 1 AM, overspreading the rest of the area to the east through the overnight hours.

Narrow window for lingering severe threat Tuesday afternoon:

Showers and embedded thunderstorms should become sub-severe come sunrise as HREF mean MUCAPE becomes a meager 100-250 J/kg. That said, lots of lift from the colliding systems should continue to force widespread light showers through the morning. At the same time, the surface cold front will continue to sag southward through our area. The cold front and rain should keep highs north of Highway 60 in the upper 50s.

The cold front placement and progression will be the main question for severe risk Tuesday. Widespread showers and storms through the morning could add cold air to the synoptic front, speeding up its southward progression with would would wash out any appreciable severe risk during the afternoon save for an elevated marginal hailer (quarter-size). This is the higher confidence scenario, confining the conditional severe risk to Ozark, Howell, and Oregon counties where our Slight Risk is situated.

That said, the warmer-biased models do keep our southern tier of counties clear of any rain, allowing for a very narrow window of decent destabilization (750-1000 J/kg SBCAPE from the HRRR/RAP). If this scenario occurs, deep-layer shear of 50-60 kts would be supportive for supercells, bringing an all hazards risk of hail up to golf balls, damaging winds up to 60 mph, and a low-end 2% chance of a weak tornado.

The timing of these storms would be a quick window between 3 and 9 PM. Start/end time will be largely dependent on the cold front position during the afternoon.

LONG TERM /TUESDAY NIGHT THROUGH MONDAY/

Issued at 300 PM CDT Mon May 4 2026

As the front makes its way through our area Tuesday night, an upper- level jet and midlevel trough begin nosing into the northwestern portion of the region. This could support additional precipitation on the backside of the front, though most of our moisture will have been pushed out with the frontal passage, so associated PoPs are capped around 30% for Wednesday. Northerly post-frontal winds don't stick around for long, and by Thursday we already start to see southerly flow starting up again as broad troughing over the west begins to push in. Highs in the 50s on Wednesday increase to 60s Thursday and 70s by Friday.

Though there is a trough on the way in, a weak surface high keeps us mostly dry for a couple of days and allows plenty of sunshine to assist the WAA with our warming trend. Weak troughing in the northerly jet may initiate scattered showers Friday afternoon with PoPs <20%. Zonal deep layer flow and strong southerly surface flow Saturday may allow some areas to reach the low 80s before our next frontal passage and associated precipitation Saturday evening through Sunday. Extended prognoses are not indicating that this activity has severe potential at this time, but that will continue to be monitored.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 614 PM CDT Mon May 4 2026

For the 00z TAFS, convection is expected to become more widespread after 04-05z this evening as a front begins to shift south into the area while a low level jet from the southwest begins to ramp up. Have convection at the 3 TAF sites after around 05-06z which will then continue through the overnight. Flight conditions will drop into MVFR and possibly IFR with any stronger convection. IFR ceilings will be possible behind the front on Tuesday with lingering showers into the morning.

SGF WATCHES/WARNINGS/ADVISORIES

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