textproduct: Kansas City/Pleasant Hill

KEY MESSAGES

- Active weather pattern continues this week.

- Strong to severe storms will be possible early Monday morning as complex of storms builds south weakening with time. Main threats will be damaging straight line winds and a short lived tornadoes- especially across northwest Missouri.

- Additional severe storms are expected Monday night into Tuesday morning as a cold front builds south across the region. Large hail, damaging winds, tornadoes and flooding are all possible with this round of thunderstorms.

DISCUSSION

Issued at 258 PM CDT Sun May 17 2026

A very active stretch of weather is expected to continue across the region with a slow moving cold front expected to be the focus for rounds of thunderstorm development. Early this afternoon, a pair of supercells developed near the front in north central Nebraska lifting northeast into southeast South Dakota along the front. Warn on forecast and CAMs are largely in decent agreement that storms will try to build south with time, though there is a bit of a cap that developing updrafts will have to work around. Convergence on along the front is expected to increase this evening as 30-50 knot low level jet develops in the open warm sector from central Texas into central and eastern Kansas. Subtle short wave across northern Kansas this afternoon is expected to lift northeast and aid in thunderstorm development along the front this evening. Storms will be developing in a fairly volatile environment with 2000-2500 J/kg of ML CAPE and 30-40 knots of bulk shear. As storms evolve into a line/ complex, they are expected to leave the cold front behind extending from central-eastern KS into central Iowa. 0-3 km helicity is currently 200-300 m2/s2, but as the low level jet increases, 0-1 km helicity is expected to increase over 300 m2/s2. Therefore, as the developing MCS builds south into northwest Missouri expect a tornado threat along with damaging wind threat. As MCS builds south of highway 36, expected storms to become outflow dominant with strait line winds becoming the primary threat and weakening in time as the complex works farther south.

Upper level jet streak is expected to round the base of the upper level trough tonight and eject into the plains tomorrow aiding to strong wind shear. Remaining front may reorient slightly as main shortwave in upper level trough rounds the base of the trough and surface low develops in western KS progressing northeast along the front throughout the day. Volatile environment is expected to develop on Monday ahead of the front with 3500-4000 J/kg of SB CAPE and 0-6 km effective shear of 30-35 knots. Storms are expected to develop along the front in eastern KS quickly growing upscale into a cyclone/developing MCS that is expected to build southeast through the evening hours. All hazards are expected with this complex of storms including damaging winds, large hail, flooding and tornadoes. Have expanded the flood watch across north central Missouri south, and may need to continue the trend tonight to include the KC metro, but didn't get too aggressive since the storms tonight are expected to be fairly progressive with expected rainfall expected to be an inch or less in most locations. With that said though, flash flood guidance is very low in locations that received copious amounts of rain last night. Precipitable water ahead of the front is expected to climb to 1.75-2.00" and with deep warm cloud processes.

Cooler and drier conditions are expected in the wake of the frontal passage Tuesday into Wednesday; however, additional precipitation is possible late week as a trough develops across the Northern Plains.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 633 PM CDT Sun May 17 2026

Deteriorating flight conditions through the overnight. Breezy low VFR conditions continue for the next few hours before degrading through the night as a thunderstorm complex moves through.

Gusty southerly winds continue ahead of the line of thunderstorms that is expected to enter the region around 05-06Z in vicinity of KSTJ. The line is expected to progress SE through the remaining terminals over the following 6 hours. High winds and heavy rainfall are the primary hazards with this line of storms. Gusty winds around 25-30 knots continue after storms more through persisting through the remainder of the period. CIGs lower to low MVFR ahead of storms with borderline MVFR/IFR conditions continuing through the end of the period.

EAX WATCHES/WARNINGS/ADVISORIES

MO...Flood Watch from 1 AM CDT Monday through Tuesday morning for MOZ020>022. Flood Watch through Tuesday morning for MOZ001>007-011>016-023- 024. KS...Flood Watch from 1 AM CDT Monday through Tuesday morning for KSZ025-102.