508 FXUS63 KTOP 180849 AFDTOPArea Forecast Discussion National Weather Service Topeka KS 349 AM CDT Thu Sep 18 2025
.KEY MESSAGES...
-A series of atmospheric waves and storm systems is keeping rain chances in much of the upcoming forecast.
-The first rounds of rain will occur today. A few storms this afternoon could produce small hail and gusty winds.
-Temperatures cool back to near normal values after a warm stretch of late summer weather.
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.DISCUSSION... Issued at 345 AM CDT Thu Sep 18 2025
A few rounds of rain are expected today as low pressure continues to sit and spin north of the area. One round is ongoing at 09Z across far eastern KS. The next will move into the area from southern and southwestern KS as a trough axis rotates around the main low. With that, chances increase later this morning and midday from southwest to northeast across the area. A few storms could then develop in eastern KS near a surface boundary later in the afternoon. If storms materialize this afternoon, small hail and gusty wind could occur. Forecast soundings from a few short-term models, including the HRRR and RAP show around 1500 J/kg of CAPE and between 20 and 30 kts of 0-6 km bulk shear. The current QPF from these multiple rounds of rain has most of the area receiving close to an inch of rainfall. Scattered higher amounts will be possible.
Rain should exit the area late today and this evening. Daytime hours Friday look dry with sunshine returning. Temperatures will be more seasonable with highs around 80 degrees. Thunderstorm chances (30-50%) return to the area on Saturday when a shortwave trough axis approaches from the west. A similar setup could lead to another round of wet weather on Sunday with chances currently ranging between 30% to 60%, the higher chances in far eastern KS. A few long range models then agree on a stout upper low moving south out of southwestern Canada and over KS by next Tuesday. If that solution verifies, it will lead to more rain and cooler temperatures by the middle of the week.
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.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1234 AM CDT Thu Sep 18 2025
Thunderstorm chances are the main concern and challenge with TAFs this period. Have included a few rounds of rain in the forecast tonight and on Friday. Timing may need to be adjusted slightly based on radar trends through the day. Otherwise, winds will be light outside of storms and clouds/visibilities will likely stay VFR.
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.TOP WATCHES/WARNINGS/ADVISORIES... None.
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DISCUSSION...Teefey AVIATION...Teefey
NWS TOP Office Area Forecast Discussion