textproduct: Kansas City/Pleasant Hill

KEY MESSAGES

- Hot conditions may continue into Wednesday for areas in central and southern Missouri.

- A few strong to severe storms are possible late this evening into the overnight hours, mainly across northern Missouri. And again Wednesday afternoon to evening, mainly along and south of I-70.

- Cooler/more seasonal temperatures move into the area for the latter half of the week and through the weekend.

UPDATE

Issued at 945 PM CDT Tue Sep 8 2026

Allowed the extreme heat warning and heat advisory to expire earlier this evening. It is possible hot temperatures will linger in far southern and southeastern portions of our forecast area on Wednesday. However, confidence is too low at this time for issuance of an additional heat advisory, given the approach of a cold front from the north during the day and potential for showers and storms in proximity to it. We will take a closer look at this potential during the overnight hours.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 205 PM CDT Tue Sep 8 2026

Broad 500-hPa ridging remains centered over the central CONUS. A shortwave and associated low pressure system are working across southern Canada with a cold front draped across the Upper Mississippi River Valley and into the Northern Plains. While today remains hot, this cold front will continue progressing south across MO tomorrow, which will bring some much needed relief from the heat and multiple rounds of showers and storms.

Broad subsidence and dry air through the column have resulted in clear skies across northern MO and northeastern KS today. This will allow temperatures to rise into the upper 90s to near 100 degrees once again today with heat indices climbing above 105 degrees this afternoon. An Extreme Heat Warning remains in effect for the KC Metro and areas south and west through 8 PM this evening. A Heat Advisory is in effect for areas along and southwest of a line from Bethany to Columbia through 8 PM. This should be the last day of heat related headlines. As the front moves through tomorrow, cloud cover and precipitation chances should mitigate the potential of reaching advisory criteria. Areas across the far southern portion of the CWA (Linn (KS), Bates, and Henry counties) may reach heat indices of 105 degrees, but these conditions shouldn't last for more than 1-2 hours, so have opted to hold off on extending the heat products for these areas.

As previously mentioned, a cold front is moving south-southeast across NE and IA this afternoon and will continue to progress into northern MO overnight tonight. 1500-2500 J/kg of MUCAPE is expected to pool along the frontal boundary, which paired with the lift associated with the front will create a setup for storms as the front moves through. The best timing for storms across northern MO appears to be as early 3 AM and lasts through sunrise before chances begin to diminish. Shear values are marginal with 20-30 kts of deep layer shear, which is enough to get some organization of storms, Model soundings across northern MO feature dry air in the low- levels creating inverted-V profiles. While most of the instability is elevated on the front, these profiles favor pulsey downburst storms, which may have enough downward momentum to punch through the stable surface layer and bring strong to damaging winds to the surface. This thinking aligns with the SPC Day 1 Convective Outlook, which outlines northwestern MO in a Marginal (Level 1 of 5) Risk for severe weather with the main hazard being damaging wind.

As the front continues to work south through the morning, showers and weak storms will be possible (50-70%), but severe weather is not anticipated as the low-levels become more saturated and the inverted-V sounding profiles becomes less prominent. MUCAPE values rebound through the afternoon and evening as the front approaches the southern periphery of the CWA bringing a renewed severe risk. As temperatures warm and daytime mixing occurs, the inverted-V profile returns beneath 2000-3000 J/kg of MUCAPE. This once again makes strong to damaging winds the primary threat, although marginally severe hail cannot be ruled out. This severe threat largely exists from the KC Metro southward during the late afternoon and early evening and into the overnight as the front exits the southern portion of the area.

Current expectations are for 0.5-1" of precipitation across the area, with locally higher amounts possible. Given the dry stretch of weather that the area has been locked in, it will take 1.5-2" of rain in 1 hour and 2.5-4" in 3 hours to create flash flooding concerns. Locally heavy rainfall will be possible with the strongest storms given the 2-2.5" PWATs that are currently in place across the area. Thus, localized flash flooding is possible, but pinning down an exact threat area is dependent on how individual storms evolve.

LONG TERM /THURSDAY THROUGH TUESDAY/

Issued at 103 PM CDT Tue Sep 8 2026

We will dry out briefly on Thursday and Friday with highs in the mid to upper 80s. However, we are shaping up to have a wet weekend. A surface low will lift out of Minnesota into Ontario, dragging an associated cold front through the Northern and Central Plains into our area. This front will bring widespread rain and highs will remain in the mid 80s for most of the forecast area. Currently models are holding rain off until late Friday night/early Saturday morning.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 704 PM CDT Tue Sep 8 2026

Main concern for the next 24 hours is the cold-frontal passage on Wednesday and associated shower/storm chances and wind shifts. VFR expected tonight with south to southwest winds around 10 kt. There may be some LLWS late tonight as a low-level jet nocturnally intensifies; however, winds may stay just elevated enough at the surface to meet TAF thresholds. On Wednesday, increasing chances for showers in the morning and storms in the afternoon (50-70 percent chance), but pinpointing more precise timing remains low confidence at this time. As a result, have kept PROB30 mention for SHRA/TSRA from late morning through the afternoon at the TAF sites for now. Winds will shift sharply to the northwest after frontal passage, which looks to be 15-18z at STJ and 17-20z at the KC TAF sites.

EAX WATCHES/WARNINGS/ADVISORIES

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