textproduct: Topeka

KEY MESSAGES

- Another round of storms develops this evening and overnight, mainly along and south of Interstate 70. The strongest storms could produce hail around quarter size, wind gusts around 60 MPH, and locally heavy rainfall.

- Heat builds this weekend into early next week with heat indices of 95-105 degrees forecast Saturday through Monday.

DISCUSSION

Issued at 239 AM CDT Thu Aug 6 2026

A perturbation moving through the quasi-zonal flow along with increased isentropic ascent along the nose of the low-level jet developed storms as anticipated last evening and into the overnight hours. Veering of the LLJ has shifted the majority of activity into Missouri with just some scattered showers and storms lingering over the forecast area. Forecast soundings show lift in the low cloud deck, favoring some drizzle and reduced visibility across north central Kansas. Fog is also possible, although confidence in dense, widespread fog is low given the cloud cover. While some patchy dense fog is possible, think cloud cover will limit dense fog and preclude the need for a Dense Fog Advisory.

Skies gradually clear through the day with mostly sunny to partly cloudy skies expected by this afternoon. Solar insolation will help temperatures rise into the 80s. A similar set-up to last evening/night will evolve tonight as the LLJ again strengthens with more mid-level energy passing overhead. CAMs differ in placement and coverage of storms, but think something closer to the 00z HRRR makes sense conceptually, with more widely scattered storms mainly along and south of Interstate 70. A few storms may form during the late afternoon or evening with inverted-V soundings favorable for some gusty winds. The main concern for any strong to severe storms comes after 9 PM through the early morning hours Friday. The strongest storms could produce hail of 1-1.25", wind gusts around 60 MPH, and locally heavy rainfall.

Rain comes to an end by Friday afternoon as a mid-level ridge across the Four Corners inches towards the Plains. 850mb temperatures warm to 22-24 degrees C, translating to surface temperatures in the upper 80s to low 90s Friday afternoon. Highs could be a few degrees warmer if precipitation and clouds clear earlier than forecast. A surface trough diving south across Iowa and Nebraska looks to be the impetus for convective development Friday afternoon and evening with some potential for this activity to move into the area Friday evening and night. Signals are mixed among guidance, so have maintained 10-30% PoPs.

The Central Plains remains on the eastern periphery of the mid-level ridge this weekend into early next week. While this does lead to gradually hotter temperatures each day through Monday, it also allows the possibility for waves to ride the ridge and generate cloud cover and precipitation across the area. The GEFS, ENS, and GEPS ensembles show a 5-15 degrees spread between the 25th-75th percentiles for highs Saturday-Monday. The NBM depicts a tighter spread, but still shows the potential for highs in the upper 80s to low 90s, if conditions are cloudier/wetter, or in the mid 90s to around 100 degrees, if dry weather and sunny skies dominate. The best chances for precipitation may come during the overnight hours, leading to a higher chance for the hotter temperatures to materialize. The current forecast has heat index values of 95-105 each afternoon from Saturday through Monday, but there remains enough uncertainty to hold off on any headlines at this range.

Ensembles favor the ridge flattening again by the middle of next week with a surface front and embedded shortwaves leading to increasing precipitation chances.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 552 AM CDT Thu Aug 6 2026

IFR to LIFR cigs to begin the period with some VSBY restriction from BR as well. Conditions slowly improve through the day, although exact timing of categorical cig changes could differ from TAF by an hour or two. Expect VFR conditions to return by late morning or early afternoon. Showers and storms develop again overnight with medium confidence in precipitation near terminals for a few hours.

TOP WATCHES/WARNINGS/ADVISORIES

None.