140 FXUS63 KTOP 050916 AFDTOPArea Forecast Discussion National Weather Service Topeka KS 416 AM CDT Fri Sep 5 2025
.KEY MESSAGES...
- Showers move through the area today with highest chances (30-70%) focused south of I-70.
- Much cooler today, then a gradual warm-up follows into next week.
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.DISCUSSION... Issued at 415 AM CDT Fri Sep 5 2025
The surface pattern as of 08Z consists of a low pressure system centered over the TX/OK panhandles and high pressure over the northern Rockies. Cold front has passed south of the area with CAA in progress. The upper air pattern remains dominated by the strong low over Ontario, resulting in cyclonic flow across much of the northern and eastern CONUS. Ridging is noted over the far western CONUS.
Showers and thunderstorms are still well west of the area in southwestern KS with stratiform rain extending into central KS. Mid- level frontogenesis should strengthen into eastern KS later this morning, helping the showers to extend east during that time. Forecast soundings indicate the profile struggles to saturate much below 750mb, however, so this dry air will probably keep rain amounts light and limit how much will reach the ground. CAMs generally show areas along and south of I-70 are most favored to see rain, with a few solutions keeping rain as far south as I-35. Have reflected this in the PoP and QPF forecast. Amounts look to be under a quarter inch for the most part, as ensemble data suggests you have to get to the southern edge of the forecast area before it looks likely to exceed that amount. Otherwise, expect the cooler air mass and cloud cover to keep temperatures in the 60s this afternoon, with lowest temperatures further south where rain chances remain highest through the afternoon. May need to watch for fog formation overnight into Saturday morning with clearing skies, nearly calm winds, and lows near crossover temperatures.
Surface high pressure slowly moves east through the weekend, leading to plenty of sunshine and highs in the 70s. The aforementioned upper ridge slides east into early next week, but looks to weaken as it does so with a weak perturbation bringing our next potential rain chance Monday night into Tuesday morning. There are some slight differences in timing and placement of that wave as is typically the case 4-5 days out. From there, the ridge looks to amplify over the central US mid-week, leading to warming temperatures and a return to closer to average conditions.
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.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1244 AM CDT Fri Sep 5 2025
A cold front is on its way, which will shift winds back to the north/northwest early this period. Most guidance keeps showers later this morning south of terminals, with the exception of the HRRR, and forecast soundings show dry air in the low levels. Will maintain the PROB30 mention with limited confidence. Otherwise, VFR conditions are forecast and winds should remain light, backing towards the southwest in the late afternoon.
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.CLIMATE... Issued at 240 PM CDT Thu Sep 4 2025
Record lowest maximum temperatures for September 5 (today):
Topeka -- 65 degrees, set in 1905; forecast -- 66 degrees. Concordia -- 59 degrees, set in 1905; forecast -- 68 degrees.
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.TOP WATCHES/WARNINGS/ADVISORIES... None.
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DISCUSSION...Picha AVIATION...Picha CLIMATE...Poage
NWS TOP Office Area Forecast Discussion