textproduct: Kansas City/Pleasant Hill

KEY MESSAGES

- Severe thunderstorms are expected to develop this afternoon along a cold front moving southeastward through the region. The best chances for storms are south of a line from Kansas City to Kirksville. Large hail, damaging winds, tornadoes, and heavy rainfall are all potential hazards from these storms.

- Southwest winds of 15 to 30 mph with occasional gusts exceeding 45 mph are expected this morning across the area.

- Heat indices approaching/exceeding 100 degrees are forecast this afternoon, especially south of I-70.

- Showers and a few thunderstorms are forecast again across west-central and central Missouri on Thursday. Severe weather is not expected.

- A strong storm system will move through the region this weekend, bringing another round of severe weather and heavy rainfall.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 233 AM CDT Wed Jun 17 2026

A northwest-flow regime is in place across the central U.S. this morning. A vigorous shortwave trough is progressing southeastward from the northern Rockies, with convection developing in advance across the Dakotas into Iowa and Minnesota. With time, this convection will organize and intensify in Iowa. Convection-allowing models have suggested the southern edge of these storms will clip far northern Missouri around/after daybreak. Though we are expecting the most intense convection to remain north of the Iowa/Missouri border, certainly cannot rule out thunderstorms roughly north of U.S. 136 this morning, and have raised PoPs in these areas accordingly. Should the storms sufficiently organize, a severe storm cannot be ruled out given the rapidly improving instability and shear. Any such storms would move east of the forecast area by late morning.

A more confident aspect of this morning's forecast is the strong/gusty winds expected across the area. An intense (60+ kt) low-level jet will traverse the region during the morning as it veers and translates eastward in advance of the aforementioned shortwave trough. Sufficient boundary-layer mixing of these strong winds aloft will occur near/after sunrise, leading to a period of unusually gusty non-thunderstorm winds for this time of year. Peak wind gusts exceeding 45 mph are probable (probabilities greater than 50 percent) in most of the forecast area. The winds should gradually subside this afternoon, as the low-level jet progresses well east of the area.

Meanwhile, a cold front trailing the Upper Midwest surface low will surge southeastward through the central Plains this afternoon. Though large-scale ascent will be fairly weak in the wake of the shortwave trough racing eastward toward the Great Lakes, the strong warm-sector southwest winds and the decently strong northwest winds upstream of the cold front will supply strong frontal convergence in a rapidly destabilizing environment this afternoon. Convection is expected to erupt readily along the front by mid-to-late afternoon (near/after 3 pm), and may do so from east to west, becoming more isolated farther west. Shear profiles are unusually strong for this time of year (0-6 km bulk wind difference exceeding 60 kt; 0-1 km SRH near or higher than 150 J/kg), with MLCAPE of 2000-4000 J/kg by late afternoon in the preconvective warm sector. This parameter space, combined with at least some orthogonal component of the shear vector relative to the initiating boundary, suggests supercell storms are favored this afternoon/evening. Kinematic/thermodynamic profiles are favorable for all severe hazards, including torrential rainfall (PWs 1.75+ inches).

The main question will be when and where storms develop, with most CAMs suggesting this will generally be near or just south of a line from Kansas City to Kirksville around/after 3 pm. Most areas to the north/northwest of this line will see little or no precipitation this afternoon/evening, but areas in advance of the storms may see locally high amounts given the substantial moisture in place. An isolated instance of flash flooding is possible (around a 20 percent chance). More likely is large to very large hail and damaging winds offered by the discrete or semi-discrete storms. The tornado potential certainly exists as well given the strong wind/shear profile in place.

Speaking of the substantial moisture, another potential hazard posed today is relatively high heat indices before convection initiates, with forecast highs soaring into the 90s and heat indices approaching/exceeding 100 degrees. Heat indices may flirt with advisory criteria, particularly south of the metro, but the duration of these high heat indices combined with uncertainty associated with developing convection preclude issuance of a heat advisory at this time.

The front will slow its southward progress tonight, perhaps lingering in our far south for much of the evening/overnight, before finally shifting farther south into the Ozarks late. However, models are hinting at a reinforcing vorticity maximum moving southeastward into the central Plains Thursday morning. CAMs are signaling a round of showers and at least isolated storms during the day Thursday, particularly in the southern CWA in closer proximity to the stalling front. Have increased PoPs for Thursday south of I-70, and would not be surprised if at least a few showers occur farther north as well. Think the better chances of severe weather will be south of the forecast area, though, in closer proximity to the front and greater instability to its south.

After today's hot weather, Thursday's high temperatures will return to more pleasant upper 70s and lower 80s. Lows on Thursday night may drop into the 50s for most locations outside of the KC metro.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 233 AM CDT Wed Jun 17 2026

Another quick-moving shortwave trough should progress southeastward through the central U.S. on Friday, but this system should be more moisture-starved and farther north of Kansas/Missouri. Expecting Friday to be dry and somewhat warmer, with highs in the mid to upper 80s. Friday night and Saturday, the pattern begins to change, with a potent vorticity maximum ejecting eastward from the western U.S. during this period. This should lead to lee cyclogenesis in vicinity of eastern Colorado or western Kansas on Saturday. The surface low will probably be quite strong, given favorable large-scale ascent downstream of the attendant vort max collocated with upper divergence from a rapidly intensifying anticyclonic upper-level jet streak. During this 24-hour period, a lengthy southerly fetch straight from the Gulf should result in substantial moisture advection. Anomalous PWs (nearing 2 inches by Saturday night) in a sufficiently unstable environment will lead to efficient precipitation production with widespread convection that develops near/east of the advancing surface low. The GFS/CMC/ECMWF ensembles are quite consistent in this general evolution, but vary considerably with timing and geographical placement (e.g., ECMWF much farther north than the GFS/CMC; CMC much slower than GFS).

Despite these uncertainties, confidence is increasing that the weekend will be an active period for our region, with both severe weather and flash flooding as potential hazards from the approaching system. Given the number of activities going on across the area this weekend, this system bears monitoring for its potential significant societal impacts. The flooding potential is especially worrisome given the still-saturated soils across the area (particularly northern Missouri) and the highly anomalous tropospheric thermodynamic profiles. Stay tuned to the latest forecasts as forecast variability gradually lowers.

A respite of dry weather is expected early next week, but longer-range models suggest another active period may follow, as a deep longwave trough develops in the central U.S. late in the month of June.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1058 PM CDT Tue Jun 16 2026

Winds gradually accelerate through the overnight with borderline LLWS possible before momentum transfer brings southerly winds to the surface. Winds really accelerate after sunrise as diurnal mixing begins. Wind gusts of 30-40 knots are anticipated with intermittent higher gusts possible. A cold front moves through the area midday to early afternoon shifting winds northwesterly. RA/TSRA is expected to develop along the front; however, guidance does favor these storms forming east of the terminals. Some isolated SHRA with VCTS is possible if the area of convective initiation shifts. Winds dissipate after sunset.

EAX WATCHES/WARNINGS/ADVISORIES

MO...Wind Advisory from 7 AM this morning to 1 PM CDT this afternoon for MOZ001>006-011>015-020-021-028-029. Wind Advisory from 7 AM this morning to 3 PM CDT this afternoon for MOZ007-008-016-017-022>025-030>033-037>040- 043>046-053-054. KS...Wind Advisory from 7 AM this morning to 1 PM CDT this afternoon for KSZ025-102>104. Wind Advisory from 7 AM this morning to 3 PM CDT this afternoon for KSZ057-060-105.