textproduct: Kansas City/Pleasant Hill

KEY MESSAGES

- Multiple rounds of rainfall anticipated across NE KS and NW MO starting this morning and continuing through Wednesday morning. Heavy downpours are expected which may lead to flash flooding. A Flood Watch is in effect for NW MO and NE KS (including the KC metro) from 1PM Tuesday through 1PM Wednesday.

- Runoff is expected to flow into creeks and streams resulting in elevated river levels and accelerated flow. Poor drainage and urban areas may also see some flooding.

- Wide range of temperatures anticipated NW MO and NE KS around 80 and central MO in the mid 90s. There is the potential for some hazardous heat across central and southern MO today and tomorrow as heat index values approach 100F-105F.

DISCUSSION

Issued at 321 AM CDT Tue Sep 15 2026

The short term pattern continues to be dominated by turbulent upper level SW flow aloft and a slow moving surface trough across eastern CO and western KS. This results in a stationary boundary which extends along the KS/NE border eastward along the MO/IA border. CAM guidance shows a broad LLJ extending across the south central Plains toward the Great Lakes. Downward mixing across the lower level warm sector is creating an area of surface convergence along the previously mentioned boundary similar to an exit region of a low level jet. This also boost warm air advection just enough to keep some residual surface instability just enough to maintain convective development across the area.

Cool outflow from storms earlier Monday evening into early Tuesday morning have stabilized the low levels just enough to gives us a short break in the precipitable action through the overnight. However, the low level warm air and moisture advection feeding directly from the moisture rich Ozarks will be able to replenish the environment consumed by the previous round of storms. The wild card in this is will there be enough forcing and instability to initiate further rounds of precipitation through the overnight (unlikely) or how will a larger scale cold front from the NW affect convective initiation. We will focus on the synoptic scale front as it will be much more influential. Current CAM guidance times this front approaching far NW MO/NE KS as sunrise approaches.

Daytime heating is expected to accelerate destabilization as warm air and moisture continue to build northward. Looking vertically the cold front exhibits a shallow slant backwards such that at 850mb the front remains in SE NE/SW IA. This creates a wide area of precipitable development that is expected to envelope much of NW MO and NE KS as the frontal system slowly moves across the region through the day today. Multiple upper level shortwaves combined with moisture convergence and lift across the frontal boundary as well as steady WAA ahead of the boundary keeps convection ongoing through much of the day. Guidance favors showers to be mostly elevated behind the surface front, but ahead of the upper level frontal features. This combined with limited shear and helicity generally constrain strong to severe potential; however, the transport of moisture upward combined with climatically high PWATs (>= 2 inches across NW MO) yield possibility for training storms with repeated heavy downpours. QPF of 2-3 inches is anticipated across NW MO with locally higher amounts possible. This brings about chances for river and flash flooding across much of northern MO and NE KS as flash flood guidance sits at 1.5 to 2 inches of rainfall per hour and 3 hours respectively. A Flood Watch remains active until Wednesday afternoon across areas where the greatest probabilities for flooding impacts are forecasted. This Flood Watch was expanded to cover the KC metro as storms look to train over the region Tuesday evening into Wednesday morning. HREF guidance 25-50 percent chances of exceeding 2 inches of accumulated rainfall with isolated 20-40 percent chances of exceeding 3 inches of rainfall. Deterministic guidance has been all over the board with QPF, but given the potential for training storms with heavy downpours, it felt prudent to extend the watch southward. CAM guidance does present a small window Tuesday evening where there is the opportunity for some isolated strong to severe storms as the synoptic cold front meets up with a weak boundary from the surface low to the west. If a storm is able to become surface based ahead of the surface cold front, there is a chance to get some isolated severe gusts out of some storms. Increased localized shear as the boundaries meet could also bring the potential from some hail or tornado, but chances remain minimal. Heavy rainfall remains the primary hazard.

Rain continues to linger across the area through Tuesday night into Wednesday morning. Looking at temperatures, rain cools down temperatures into 70s and 80s across NW MO and NE KS with upper 90s expected across central MO today. This trend continues into Wednesday where a narrow area of hazardous heat is possible across Cooper county and points south and west with heat index values approaching 100-105F. The extended pattern remains fairly active with the area remaining in the periphery of a synoptic scale high and a lower level lee trough. This also looks to lift highs back toward the 90s as the end of the week approaches before a substantial wave moves through the area this weekend bringing additional precipitation chances. Additional digging trough keep storm chances around through Monday evening before ridging dries us off early to mid next week.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1224 PM CDT Tue Sep 15 2026

VFR conds will prevail thru 23Z-00Z when mod tsra will move into the into the terminals. Storms are expected to cont at the TAF sites thru 13Z-15Z with reduced vis to 3-5SM. Cigs will remain VFR thru 00Z when bkn cigs around 4kft are fcst (except STJ which will become MVFR aft 23Z). We will then see a gradual lowering of cigs thru the evening with cigs dropping into MVFR around 03Z-05Z and into IFR btn 06Z-08Z. Winds to begin the TAF pd will be out of the W around 10kts (except STJ which will begin he TAF northerly) becmg northerly around 10kts aft 00Z. By 03Z-05Z winds will shift to the east while remaining around 10kts.

EAX WATCHES/WARNINGS/ADVISORIES

MO...Flood Watch through Wednesday afternoon for MOZ001>006-011>015- 020>022-028-029-037. KS...Flood Watch through Wednesday afternoon for KSZ025-102>105.