Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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708 FXUS63 KTOP 122328 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 628 PM CDT Wed Jun 12 2024 .KEY MESSAGES... - Hot and humid Thursday with afternoon heat indices of 102-108 degrees. A Heat Advisory has been issued from noon-8pm. - Isolated to scattered storms Thursday late afternoon into the evening. These storms could be severe with large hail and damaging wind gusts being the main hazards. - Above-normal temperatures continue into early next week. && .DISCUSSION... Issued at 321 PM CDT Wed Jun 12 2024 This afternoon, a shortwave is advancing east across the Upper Midwest with mid-level ridging over the Desert Southwest. Gusty south-southwest winds and plentiful sunshine have boosted temperatures into the 90s across the area. Surface winds of 5-10mph overnight will keep lows in the low 70s. The mid-level ridge builds northeast on Thursday with 850mb temperatures warming to 24-27 degrees C. Breezy southwest winds allow for good mixing and will create the hottest day of the season so far with highs in the low 100s across central Kansas and in the mid 90s across far eastern Kansas. Along with these hot temperatures, dewpoints in the mid 60s to low 70s will lead to heat indices of 102-108 degrees during the afternoon. Some uncertainty remains in how high heat indices will reach as deeper mixing would lead to hotter ambient temperatures, but also lower dewpoints. Even so, confidence is high that heat indices of 102-108 degrees will be common across the area and Heat Advisory has been issued from noon to 8pm Thursday. A wave of energy pushing east-southeast across the Great Lakes will shunt a cold front into northeast Kansas during the late afternoon and evening hours Thursday. The hot and humid airmass will feature 4000-5000 J/kg of MUCAPE along with 30-40kts of effective shear, supportive of severe thunderstorms. The main uncertainty is in the coverage of storms given a lack of large- scale ascent. Convergence along the front is expected to be enough to support isolated to scattered storms to develop during the late afternoon and evening (best chances in the 5-9pm timeframe). Any storm that develops will quickly become severe with inverted-V soundings supporting severe wind gusts of 60-70mph along with large hail up to golf-ball size. There is a chance that a modest cap and insufficient convergence along the front could preclude convective development altogether. The front pushes through the area by early Friday before lifting back north as a warm front on Friday as a shortwave trough approaches the Plains. Convection that develops during the evening across western and central Kansas will be shunted east by the ejecting trough and bring storms into the area during the evening into the overnight hours. The environment could support severe storms with large hail and damaging wind gusts with this round, but details remain uncertain at this point. The trough is slow to progress through the region and is progged to still be working its way east on Saturday, bringing another chance of storms to the area. Mainly dry conditions are expected Sunday and Monday before the next wave and front approach the area Tuesday. Highs will generally be in the low to mid 90s Friday into next week. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 626 PM CDT Wed Jun 12 2024 Gusty southerly winds should diminish by 01Z, followed by sustained winds around 10 kt through the night. If the BL decouples more than forecast with lighter sfc winds, then there could be some LLWS overnight, but as it stands now, this looks too marginal to include in the forecast. Winds pick up again mid to late morning with gusts around 20 kt through the day. There is a chance for storms to develop along an approaching cold front in the last few hours of the period, but coverage varies among guidance leading to low confidence in impacts at TAF sites at this time. && .TOP WATCHES/WARNINGS/ADVISORIES... Heat Advisory from 1 PM to 8 PM CDT Thursday for KSZ008-KSZ009- KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-KSZ026- KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-KSZ039-KSZ040-KSZ054-KSZ055- KSZ056-KSZ058-KSZ059. && $$ DISCUSSION...Flanagan AVIATION...Picha