textproduct: Topeka

KEY MESSAGES

- Cold front this afternoon brings scattered showers and a few weak thunderstorms.

- Frost potential north of I-70 Friday and Saturday mornings.

- Turning warmer again Sunday into early next week.

DISCUSSION

Issued at 205 AM CDT Thu Apr 30 2026

We remain in a cooler pattern this morning, thanks to a seasonably deep upper low spinning over the Great Lakes. A shortwave pivoting around this low is dropping southeast over the northern Plains, and will push a weak cold front southward through the area this afternoon. Moisture return will be very limited ahead of the front, but cold air aloft will be enough to help a few hundred J/kg of surface based CAPE to develop. Coupled with the frontal forcing, we should see a few afternoon showers and perhaps weak thunderstorms develop. These should quickly weaken and move off to the south after sunset, as high pressure approaches from the north. With the chilly airmass and light winds, we may see some frost develop across parts of northern KS. High cloud cover could help prevent frost formation though, so will hold off on any Frost Advisory for now.

Friday into Friday night will see a near repeat of Thursday. A weak shortwave will push a subtle cold front southward through the area, likely enough for a few sprinkles or very brief showers. High pressure moving overhead then brings another chance for frost across northern Kansas Saturday morning.

After another cooler day Saturday, we see a warmer pattern return for the first part of next week. The eastern CONUS trough weakens and lifts northeast in response to an upper low moving onshore to California, allowing heights to rise across the Plains. Southwesterly low-level flow should help temperatures quickly warm back to around 80 for Sunday and Monday.

Uncertainty increases for the middle of next week. The upper low over California will move eastward toward the Plains, while at the same time a strong shortwave over western Canada will dive southeast. How these two systems interact will be key for sensible weather impacts here. If the southern stream upper low has more room to lift farther north, that would keep warmer temperatures into Tuesday and increase thunderstorm chances Tuesday PM as moisture and shear increase. However a majority guidance (70%) indicates the northern stream system will suppress the upper low to our south, with the cold front moving through our area late Monday or early Tuesday. This would keep Tuesday much cooler and with less of a thunderstorm risk, though rain chances would still increase and linger through Wednesday in either scenario.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 536 AM CDT Thu Apr 30 2026

Cold front is expected to move north to south across the main terminals late afternoon into early evening (20-23 UTC). Should see some scattered showers and perhaps a weak thunderstorm as the front moves through, with winds around 10 kts veering from the west to north. Ceilings remain VFR, around 5 kft and clearing behind the front.

TOP WATCHES/WARNINGS/ADVISORIES

None.