textproduct: Topeka

KEY MESSAGES

- Scattered showers are possible Thursday (20-30% chance) with isolated thunderstorms.

- Cooler temperatures remain through this week into the first part of the weekend, then warm up next week.

- Lows Friday and Saturday mornings fall back to the mid 30s, mainly north of I-70, which could lead to frost formation.

DISCUSSION

Issued at 136 PM CDT Wed Apr 29 2026

Broad troughing over Canada and the US has led to mainly zonal flow over the forecast area this afternoon, with an upper low noted in the Pacific off the coast of southern CA. Sfc high pressure is placed in the Central Plains, leading to quiet weather with fairly light winds today. A few more hours of heating will bring our high temperatures into the low to mid 60s.

As we head into tonight and early Thursday, weak perturbations within the northwest flow over the northern/central Rockies along with some mid-level frontogenesis will help to develop scattered showers in CO and the High Plains. The better lift from the frontogenesis appears to be towards central KS Thursday morning, which is where CAMs have most of the rain coverage. Towards northeast KS, there may be just enough convergence along a weak sfc boundary for a few other showers to develop there and into MO/IA. However, a look at forecast soundings doesn't show as much moisture and lift for northeast KS. Coverage increases a bit into the afternoon before the wave pushes south through the evening. Models show a couple hundred J/kg of elevated instability, so a few isolated thunderstorms can't entirely be ruled out, but most activity looks to remain as light showers.

For the end of the week, our area ends up between two systems with a large upper low over the northeastern US/southeastern Canada and the Pacific low turning into a weaker shortwave traversing across the southern US. Medium-range guidance does show a shortwave on the southwest periphery of the larger system moving through our area Friday night. Consensus keeps a dry forecast with a lack of moisture for this system. Temperatures remain cool through this time period with little spread in the ensemble data. Friday and Saturday mornings could bring areas of frost to northern parts of the area, mainly north of I-70, where lows are forecast in the mid 30s along with light winds and mainly clear skies.

By the start of next week, the upper pattern has low-amplitude ridging moving towards the area, still keeping us in between two systems to our east and west. The increasing heights favor a warming trend with highs returning to the 70s and 80s, but it should be noted that the spread still increases towards the end of the forecast period. Tuesday looks like the next time period to watch for increasing storm chances as an upper low approaches from the southwest US.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1219 PM CDT Wed Apr 29 2026

VFR conditions will prevail for the period. Some diurnal cumulus around 3-4 kft has developed early this afternoon, and satellite shows it scattering out a bit, but will maintain this in the TAFs until sunset. Otherwise, north winds persist this afternoon, then become light and variable through the night and eventually turn westerly late in the period.

TOP WATCHES/WARNINGS/ADVISORIES

None.