textproduct: Topeka

KEY MESSAGES

- Severe storms possible (20-40%) mainly along and southeast of I-35 late this afternoon with hail and wind as primary threats.

- A better setup for severe storms comes Friday afternoon and evening. All hazards are possible, but plenty of uncertainty remains.

- Much cooler this weekend with some frost/freeze potential, then moderating temperatures into next week.

DISCUSSION

Issued at 236 PM CDT Wed Apr 15 2026

Upper trough axis is moving across the Central Plains this afternoon with VAD wind profilers showing a 40-60 kt speed max associated with this wave. Next trough is noted off the PNW coast. At the surface, low pressure sits near the MO River Valley with a dryline extending south from northeast through east central KS, followed by a weak cold front coming from north central KS. The scattering of this morning's cloud cover has allowed for the atmosphere ahead of the dryline to destabilize with 1500-2500 J/kg of MLCAPE and 45-55 kts of effective bulk shear, per SPC mesoanalysis. A majority of the CAMs have isolated to scattered storms developing along the dryline by 21z mostly east of the forecast area, except perhaps areas southeast of I-35. The NAM Nest has consistently been slightly earlier and further west with initiation, probably because it is slower to bring the dry air east. Based on soundings from the RAP, HRRR, and RRFS, it appears that by the time better forcing arrives from the front and upper-level support, low levels dry out and become less supportive of thunderstorms. Whether or not we see any severe storms this afternoon will depend on whether all the ingredients can come together in time before the dryline pushes east. It's a short time window (3-5pm) for this to occur before storms are likely to be east of the area entirely.

Thursday gives us a bit of a break in between the two systems. Winds quickly turn back to the south and strengthen later in the day and especially night as lee cyclogenesis occurs ahead of the next upper trough. This increase in the low-level wind field will help to advect moisture back into the area Thursday night into Friday. Before that happens, however, we do still have a dry air mass in place Thursday afternoon particularly towards central KS. While RH looks low, conditions appear too marginal to have confidence in Red Flag criteria and join our western neighbors in fire headlines. Although it is possible for wind gusts to 20-25mph to bring elevated fire danger to north central KS for a few hours.

Heading into Friday, the next upper trough progresses across the Plains as well as the next sfc low and cold front. There are still some differences in timing, which will impact the exact locations for storms. In any case, instability and shear ahead of the front would be sufficient for severe storms. Shear vectors look to have some component parallel to the upper flow and/or the orientation of the sfc front, which would point more to a line of storms developing and growing quickly upscale. With all this in mind, could see some large hail with initial storms turning to more of a damaging wind threat, possibly with embedded tornadoes. Flooding could become a risk later if storms train over the same areas.

Much cooler air comes in behind the front with highs dropping back to the upper 50s to low 60s for Saturday. Lows in the 30s Saturday and especially Sunday morning bring some concern for possible frost conditions, particularly north of I-70. Upper ridging and associated height rises across the central part of the country would then favor a warming trend into the early part of next week, alongside dry weather.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 541 PM CDT Wed Apr 15 2026

Models show a signal for some stratus and fog developing across east central KS. Right now, most of this guidance keeps it south of TOP and FOE. But the 20Z RAP tries to bring it into the terminals. For now have kept a VFR forecast and will reevaluate the IFR potential through the evening. A strengthening pressure gradient Thur should cause southerly winds to become gusty in the afternoon.

TOP WATCHES/WARNINGS/ADVISORIES

None.