Area Forecast Discussion

KEY MESSAGES

- Multiple rounds of storms will bring a flooding risk, especially north of the Missouri River, through the middle to later part of the work week.

- Round 1 - Monday Morning: The severe weather threat from storms this morning is low, but there may be some hail to 1" in the strongest cells across northwestern and northern Missouri. Locally heavy rainfall is also possible.

- Round 2 - Monday Afternoon - Evening: There is a Slight Risk in far northwestern Missouri. If storms develop/ move into far northwestern Missouri, large hail, damaging winds, and tornadoes are possible.

- Round 3 - Tuesday Afternoon - Overnight: There is a Marginal Risk for severe storms for Tuesday afternoon into the evening hours. Strong to damaging wind gusts and hail are the main hazards. Storms become more widespread overnight with heavy rainfall likely across northern Missouri.

DISCUSSION

Issued at 150 AM CDT Mon Sep 14 2026

Very active weather is expected over the first half of the work week with multiple rounds of storms anticipated. For this morning, as of writing this paragraph at 06Z, convective initiation is underway in southeastern Nebraska and northeastern Kansas. This is developing in an area of strong isentropic ascent noted from the 310K to 315K surfaces. The threat of severe weather is low with this activity due to only modest and elevated instability. But there may be cells that occasionally push to near severe thresholds with hail being the main hazard. Additionally, locally heavy rain, which will act to prime the area for subsequent events, is likely with this activity as ample moisture is transported into the area.

This initial activity will lift northeast through the morning hours, leading into the next round of storms for the afternoon and evening hours. It's uncertain if storms will be able to develop/ overcome the convective inhibition from the morning activity, but if they do they will primarily affect Nebraska and Iowa. However, the risk may bleed into northwestern Missouri with time and with MLCAPE in the 1500-2000 J/kg range with potentially 30-35kts of deep-layer shear, large hail, damaging winds, and tornadoes look possible. This activity should slide south through the overnight hours as its cold pool builds south, but will be losing its strength as it does. But, that boundary may become the focus for additional storms Tuesday afternoon.

An unseasonably moist airmass will build into the area south of this boundary, with dewpoints in the lower 70s expected. Strong daytime heating of this moist airmass will lead to potentially substantial CAPE, possibly in excess of 2000 J/kg. With stronger mid to upper- level flow still north of the area, deep-layer shear looks weaker. Forecast soundings, particularly from the NAM, suggest deep mixing/ steep lapse rates will occur in the lowest 5000 ft of the atmosphere. If storms are able to develop in this environment damaging downbursts winds are the most likely hazard. Further north, into the overnight hours, convection should become more widespread, though with a more limited severe weather threat. But its this activity that will pose the greatest risk for flooding rainfall, with widespread 1-3" rainfall amounts across northern Missouri possible from just this round of storms. Locally heavier amounts are likely depending on where storms do develop and eventually train given flow that is essentially parallel to the boundary.

Additionally, with the hot and humid conditions anticipated, a heat advisory may be needed for areas south of I-70 Tuesday afternoon.

And in the 50 minutes it took to write the remainder of this, storms have blossomed in southeastern Nebraska and northeastern Kansas, and are moving in northwestern Missouri. So I'll be cutting this discussion a little short.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 133 PM CDT Mon Sep 14 2026

VFR conditions will last through the forecast period. Southeasterly winds are gusting 25-30KT this afternoon, but will diminish after sunset this evening. Winds shift westerly and then northwesterly with the passage of a cold front near the end of the forecast period. Have included a PROB30 at KSTJ for -TSRA from 14-18z for scattered thunderstorms behind the front, but the greatest chance for widespread showers and thunderstorms begins after the end of the 18Z TAF period.

EAX WATCHES / WARNINGS / ADVISORIES

MO...Flood Watch from Tuesday afternoon through Wednesday afternoon for MOZ001>006-011>015-020>022. KS...Flood Watch from Tuesday afternoon through Wednesday afternoon for KSZ025-102.