textproduct: Kansas City/Pleasant Hill

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 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 2 - 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.

- A Flood Watch is in effect from 1 pm Tuesday through 1 pm Wednesday as storms become more widespread overnight with heavy rainfall likely across northern Missouri.

DISCUSSION

Issued at 138 PM CDT Mon Sep 14 2026

The current upper-level pattern consists of a 500-hPa ridge centered over roughly the Great Lakes region with a shortwave moving across the Rockies along Canadian border. At the surface, high pressure is situated over the Great Lakes and lee cyclogenesis is ongoing in the Northern Plains. A warm front extending from the surface cyclone is currently (as of 3 PM) lifting through the KC Metro area and into northern MO. Ahead of the front, temperatures are in the lower 80s, while temperatures in the low-to-mid 90s are present behind the front. As such, a gradient in high temperatures is expected from northeast to southwest across the CWA today. The pressure gradient between the high and low pressure centers will be enough to create some gusty (30-35 mph) southerly winds this afternoon as well.

As the surface cyclone lifts into southern Canada this evening, a cold front will drop across the Northern Plains towards the Lower Missouri Valley. This front is progged to stall out across northern MO and become the focus for multiple rounds of showers and storms over the next 2-3 days.

The first opportunity for showers and storms comes late this evening and into the overnight hours across NW MO. An observed 18Z sounding from Omaha depicts 1500 J/kg of MUCAPE, however, a stout cap is in place over the lowest 1-km. Of note, however, is that this sounding was taken north of the warm front, so surface destabilization should occur as the front passes overhead. Model soundings feature 2000-3000 J/kg of MLCAPE behind the front with 30-40 kts of deep layer shear. This parameter space is favorable for organized storm development, however, the best forcing and shear for storm longevity is focused in eastern NE and western IA beneath the upper-level shortwave. Aside from far northwest MO, forcing and shear will be tougher to come by across the area. As such, the best chances (50-70%) are confined to areas along and north of US-136.

Within this area of potential storm development, steep mid- level lapse rates (7-8 C/km) will favor large hail development. Additionally, 0-1 km shear values of 25-30 kts and cyclonically curved hodographs will lend to 0-1 km SRH values of 200-300 m2/s2, which point to a potential tornado threat with any storms that develop. The one caveat here is that most RAP soundings still show a cap in place, which would limit surface-based convection and limit tornado potential. As such, uncertainty remains as to the tornado potential across northwestern MO this evening, but it is worth noting that the chances are non-zero, particularly with a warm front in play. But as previous mentioned, the best parameter space for severe weather looks to be focused north of the CWA where the SPC Slight (Level 2 of 5) Risk exists, with all hazards (large hail, damaging winds, and tornadoes) in play.

Moving into Tuesday, the cold front will move into northern MO and stall out somewhere around the Missouri River. Sustained southwesterly flow and 1500-2500 J/kg of MUCAPE atop the front will lead to storm formation (60-80%) tomorrow afternoon/evening across northern MO. Deep layer shear will be marginally favorable (20-30 kts) for storm organization, so the chances for severe weather are low, but not zero. The bigger concern is for flooding as the front will be a continued source of lift through the evening and overnight hours. With PWATs of 2"+, the current forecast calls for 1-3" of rain across northern MO tomorrow night, with locally higher amounts possible. This, on top of the 5"+ that many areas received this morning, will set the stage for a potential flooding threat. To account for this, a Flood Watch has been issued for areas along and north of US-36 and west of US-65 from 18Z tomorrow through 18Z on Wednesday. It is not out of the question that the watch will need to be expanded south, but have kept the KC Metro out for now.

Areas south of the cold front across central MO tomorrow will see another seasonably hot day with temperatures climbing into mid-to-upper 90s with heat indices approaching 105 degrees. Given cloud cover and a front in play, have opted to hold off on a Heat Advisory with this forecast cycle, but one may be needed for tomorrow afternoon across the far southern portion of the CWA.

The stalled front is expected to lift back to the north as a warm front on Wednesday bringing highs in the upper 80s and lower 90s back to northern MO over the next few days. Current long range model guidance depicts another shortwave moving across the Northern Plains towards the end of the week. A surface cyclone will accompany this shortwave, which will push a cold front across the Central Plains and bring cooler temperatures (highs in the 70s) to the area. However, a good amount of uncertainty remains with this forecast given differences in the empirical models at this range.

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.