Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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124 FXUS63 KTOP 231039 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 539 AM CDT Thu May 23 2024 .KEY MESSAGES... - Severe thunderstorms chances increase this afternoon/evening with best chances overnight. - Additional storms, some severe, Saturday into Saturday night. - Trending drier Monday-Wednesday of next week with highs in the 70s and 80s. && .DISCUSSION... Issued at 321 AM CDT Thu May 23 2024 Zonal flow exists across the central Plains this morning ahead of a closed low centered over Idaho. A weak perturbation in the flow has generated some showers and thunderstorms across central Kansas; this activity will impact north central Kansas early this morning before dissipating just after sunrise. Patchy fog has been observed across east central Kansas where the low-level wind field is weaker. Fog will burn off quickly after sunrise. Southerly low-level flow strengthens through the day today, lifting a warm front north and raising dewpoints into the mid 60s. A dryline is progged to reside across western/central Kansas by this afternoon with the warm sector environment featuring 2500-3500 J/kg of surface based CAPE and 30-40kts of effective shear. A lack of obvious large- scale ascent leads to lower confidence in storms impacting the area late this afternoon into the evening as the capping inversion erodes. There remains a 20-35% chance for storms to develop either along the dryline or within the broad isentropic ascent. If ascent is sufficient for convective initiation to occur, the environment supports severe storms with large hail and damaging wind gusts being the main hazards. Low-level hodographs depict curvature of the lowest 1km or so which supports a low end tornado threat as well. Better ascent arrives overnight as a closed low ejects across the northern Plains, shunting a cold front through the area during the overnight hours. Storms that develop in central Nebraska during the evening are expected to quickly grow upscale into a line of storms and dive east- southeast through the late evening and overnight hours. Uncertainty remains in the intensity of these storms as they move into the area, especially with southward extent which will be further removed from the main wave. CAMs show differing solutions in placement and strength of the QLCS across northeast Kansas including some that keep the MCS largely north of the forecast area. Nonetheless, the environment will still be favorable for severe storms into the overnight period although increasing CIN supports a weakening trend as the MCS advances southeast. Damaging wind gusts will be the main hazard with these storms; further enhancement and veering of the low-level jet suggest the potential for QLCS mesovortices as well if the cold pool doesn`t advance ahead of the leading edge of storms. Showers and storms linger through the morning on Friday before skies clear for the afternoon with highs in the 70s. Another trough approaches on Saturday with increasing southerly low-level flow lifting a warm front back north and a dryline setting up across western and central Kansas again. The aforementioned wave ejects across the central Plains during the afternoon and evening leading to greater large-scale ascent across the area than will be present today. Even so, uncertainty exists in storm coverage and placement of the warm front, but the environment south of the front will be favorable for severe storms. Stay tuned as forecast details will become clearer as the event approaches. Another cold front moves through Sunday morning, but showers and some storms may linger through the day as the upper low is slow to push east. Ensembles favor an eastern trough, western ridge pattern Monday through midweek leading to mostly dry conditions and highs in the 70s and 80s. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 539 AM CDT Thu May 23 2024 VFR conditions expected. Winds increase from the south-southeast this morning with gusts of 20-25kts through the afternoon. Confidence in late afternoon or evening storms remains too low for inclusion. Better chances for storms come near the end of the period as a cold front moves through. Coverage of storms remains uncertain, so have input VCSH for now. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Flanagan AVIATION...Flanagan