textproduct: Topeka

KEY MESSAGES

- Warm and Humid again today. Heat index values ranging from 100-105 degrees can be expected.

- Strong to severe storms possible across northeast and central KS this afternoon/evening - large hail and damaging winds are main concerns, but an isolated tornado cannot be ruled out.

- A stronger cold front sweeps across the area Thursday afternoon. Additional chances for strong/severe storms may be possible across far east-central KS and southeast KS.

- Active pattern continues into the weekend with storm chances, but overall cooler pattern.

DISCUSSION

Issued at 410 AM CDT Wed Jun 10 2026

Mid-level water vapor imagery this morning shows southwesterly flow across the central Plains with embedded waves that had previously led to afternoon and evening convection across the region. This is all associated with a large, negatively-tilted wave over the northern Plains and Rockies. Over the next few days, this upper wave will remain near stationary as a digging jet streak approaches the wave from the PNW. This will keep southwesterly flow over much of the central Plains. For the remainder of the day today, the upper trough axis will help to deepen a lee cyclone and trough across southeast Colorado. Tight pressure gradients will keep the BL fairly mixed, but afternoon heating and dewpoints around 70 will again make things feel very muggy. Expect afternoon heat indicies to top out in the low 100s.

A weak boundary associated with the surface trough passes into central Kansas by this afternoon, providing weak low-level convergence across central and eastern KS by peak heating hours. Given no change in the hot and humid air mass, MUCAPE this afternoon will likely exceed 4500 J/kg as surface heating slowly erodes inhibition by 3-4 PM. Intense thunderstorm development along the weak frontal boundary will be expected later this afternoon and evening and given the thermodynamic parameters and 0-6 km bulk shear magnitudes increasing to 35-40 knots, supercellular structures in storms can be expected as well. It appears given the vertical wind shear profiles and low-level vector orientation, very large hail (up to 2") and damaging winds (60-70 mph) will be the main threats in severe storms. An isolated tornado threat cannot be ruled out but given the veered orientation of the low-level and deep shear vectors, it may be difficult to keep storms isolated and interaction- free this evening. CAMs seem to hint at this storm interaction along the boundary this evening as many models kill most convection a few hours after initiation. Another feature that my need to be watched for mesoscale convective initiation by the afternoon is an MCV that is currently along the KS/OK border. Putting a track on this feature brings it into northeast KS and northwest MO by the mid to late afternoon, so this may also become a focal point for convection by the afternoon. Inhibition behind the MCV may also act to delay CI across central KS until the early evening hours with better CI chances closer to far northeast KS where the MCV and better jet dynamics will reside.

Overnight into Thursday, the weak boundary lifts back north amidst strong southerly WAA. The main ejection of the mid-level trough will push across the northern and central Rockies Thursday mid-day as a deepening 996mb surface low pushes into north-central KS. A quick progression of the surface low and trough continues to be the mantra for CAMs Thursday afternoon as many have the boundary nearly through east-central KS by 2-3 PM. CI would not be overly likely along the boundary until the later afternoon hours, but given a warm sector characterized by 4000 J/kg of CAPE and 25-40 knots of deep shear, parcels that overcome diurnal inhibition will likely strengthen quickly. Given the progressive nature of this upper wave and deep shear vector orientation, convection along the boundary in eastern and southeast KS will likely 'unzip' by the peak heating hours, growing upscale quickly. This keeps main hazards as damaging winds with some isolated large hail (mainly within early phases of convection). Areas south and east of the cold front Thursday afternoon will again experience hot any muggy conditions with heat index values topping out in the low 100s.

A cooler and less humid air mass moves in behind the boundary for Friday as high temperatures top out in the mid 80s with very pleasant humidity. The dry weather will not last long after the passage of the low-level ridge axis by Friday night into Saturday morning. Flow returns back to the south/southwest with modest isentropic ascent and moisture advection increasing PoPs Saturday morning. Mid-level vorticity embedded in quasi-zonal flow will help to push a weak boundary across the area Saturday keeping rain and thunderstorms likely. PWATs Saturday afternoon will be around 1.5-2" and with moderately-slow storm motions, heavy rain and flooding may again become a possibility. LREF probabilities of 24 hour QPF over 1 inch is still fairly modest - maxing out around 33% across east- central KS and west-central MO. Rain/storm chances continue into Sunday as the surface boundary stalls near the Ozarks. With persistent mid-level vorticity within the zonal flow pattern aloft, an axis of heavy QPF seems likely. Current thinking and model solutions keep areas across southeast KS and southwestern MO as the current focal point of QPF, but will continue to watch this set up for any shifts north. If any good news comes with all these rain chances is the cooler weather that will accompany it. Temperatures Sunday through Tuesday should be much cooler than average, topping out in the 70s across the area. Mid-level ridge building seems to move into the central US by later next week that could return the heat and humidity, so enjoy the cooler weather while it is here for the weekend and early next week!

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 623 AM CDT Wed Jun 10 2026

Added a TEMPO group for isolated showers/thunder through this morning as a weak MCV tracks over the terminals. This should keep mid-level clouds a bit more broken until the afternoon but should remain VFR. Additionally, opted to keep convection this evening as a PROB30 for KTOP and KFOE as model guidance have a wide variety of times for convective initiation. Convection should come to an end around 9 PM with winds increasing out of the south again by the late period.

TOP WATCHES/WARNINGS/ADVISORIES

None.