Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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886 FXUS63 KTOP 200209 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 909 PM CDT Wed Jun 19 2024 .KEY MESSAGES... - Thunderstorms will continue this afternoon, and should come to an end Thursday. - Friday looks dry, and heat will begin to build through the weekend. Above average temperatures through next week. - Chances for thunderstorms will return Saturday, and off-and-on storms will persist through the beginning of the week. && .DISCUSSION... Issued at 234 PM CDT Wed Jun 19 2024 This afternoon, a stationary front that was draped across Kansas was responsible for continued convection across the region. Cooler temperatures are filtering in behind the front, and most of the area is solidly in the 70s. The WPC has issued a Slight Risk for heavy rainfall across the southwestern portion of the area, areas which received significant rainfall last night. With saturated soils, some flooding will be possible through the evening hours. The 12Z sounding from TOP showed a PW value of around 1.8 inches, above the 90th percentile for today. Overnight, the stationary front will become a warm front and begin to move to the north. Isolated convection will continue area wide as the front lifts, but forcing is weak and models do not have a good handle on where storms are most likely. Because of that uncertainty, precipitation chances were introduced, but kept low (15-25%). By tomorrow morning, most of the storms should be mainly north of Interstate 70, and continue moving north out of the area by the afternoon. Warmer air is set to return as the area dries out tomorrow, and highs between 85-90 degrees should make for a mostly pleasant afternoon. Given that the forcing has left the area, the chance for thunderstorms in the afternoon is low. Some models indicate the chance of widely scattered pulse storms, but opted to keep low chances (15-20%) contained to the far northeastern corner of Kansas. There will be around 1000 J/Kg of SBCAPE, but subsidence in the vertical profile should help to limit convection. Friday looks dry, as the ridge begins to build in. Temperatures will reach into the low 90s, and partly cloudy skies will make for a nice day. Heat indices may reach 100 in some spots, but heat isn`t a big concern for Friday. Heat may become more of an issue later on in the forecast period, as Saturday has forecast heat indices up to 105 degrees in some spots. Saturday afternoon will also feature another round of storms, courtesy of a trough in the upper Plains and a draping boundary across the region. High instability (3000 J/Kg on the NAM) will support thunderstorms, and effective shear of 30-40 knots may be enough for potential severe storms, but confidence remains low. Sunday will bring a brief relief from the excessive heat, though heat indices will still likely reach 100 across the area. The more concerning part of the forecast is in the long term, as the forecast for next week is beginning to show a high heat signal. The NBM shows heat indices approaching 105 from Monday - Wednesday, with Tuesday potentially being the hottest. Confidence is increasing in excessive heat for the first half of next week. Northeastern Kansas doesn`t look like it will be completely underneath the ridge, and NW flow could provide ample chances for thunderstorms through next week. Any storms could provide relief from the higher temperatures. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 903 PM CDT Wed Jun 19 2024 Update to 00Z discussion...00Z sounding from KTOP shows a stronger inversion layer in place than forecast. This should allow for low level clouds to remain in place with more certainty helping to keep IFR conditions a higher probability through the overnight hours. Still could see some BR also reduce vis as moisture content of the air remains high with mostly calm winds. A few showers may develop as well with some briefly developing lightning. The low level moist layer is very thin so should mix out by around mid morning. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Montgomery AVIATION...Drake