Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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580 FXUS63 KTOP 201949 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 249 PM CDT Thu Jun 20 2024 .KEY MESSAGES... - Isolated showers and storms possible across far eastern/northeastern Kansas this afternoon (15-20%) - Hot and muggy conditions continue over the next week with Saturday, Monday and Tuesday seeing the highest heat indices. - Rain and storm chances return Saturday afternoon and evening, some becoming strong to severe. && .DISCUSSION... Issued at 248 PM CDT Thu Jun 20 2024 Happy Summer solstice! A hot and muggy solstice is underway across northeastern Kansas as a large upper level ridge set up over the southeastern US keeps a warm and moist air mass near the surface. PBL mixing this afternoon has led to a widespread cu field, especially south of a weak surface boundary that has slowly pushed its way north towards the Topeka area. Enhanced convergence along the boundary can be seen on visible satellite imagery as a few thunderstorms have developed over northern MO where surface convergence has helped to lift parcels to their LFC. Over the remainder of the afternoon, isolated showers and a thunderstorm or two will be possible (15-20%) across eastern KS, especially where cu can congeal enough to tap into the elevated instability. ML lapse rates will remain weak, promoting weaker updrafts, and with little shear to work with, not expecting any severe storms this afternoon or evening. High temperatures area-wide will top out in the low 90s with temperatures falling back into the low 70s by sunrise Friday morning. Cannot rule out some patchy fog development Friday morning, mainly in low-lying areas, but not confident in any widespread development. Similar conditions can be expected over the afternoon Friday with highs reaching the low 90s and a slight chance for an isolated storm. Confidence in storm development Friday afternoon is a bit lower than this afternoon as lift will be limited and diffuse. Most areas will remain dry, but cannot rule out an isolated (10-15%) non- severe shower/storm. Come Saturday, the upper-level ridge retrogrades west towards Texas as vorticity maximums associated with a deamplifying trough across the western CONUS advect east of the Rockies. A deepening lee cyclone Saturday afternoon will push its way across northern Kansas, increasing chances for rain and storms for northeastern KS by the afternoon and evening. A few storms that can develop along the boundary Saturday afternoon and evening could become strong to severe with the presence of 0-6 km shear ranging from 30-35 knots and SBCAPE between 1200-2000 J/kg. Hazards with the strongest storms would be hail up to the size of quarters and damaging winds to 60 mph. Ahead of the boundary, southwesterly low-level flow will help to advect in hot 850mb temps leading to afternoon highs warming into the mid to upper 90s. With dewpoints still hovering in the low 70s, heat indices will approach advisory criteria. The remainder of the weekend and into early next week will remain fairly dry with oppressive heat building back into the area by Monday and Tuesday with the continued retrogression of the mid-level ridge. Upper 90s to low 100s will be expected across the area and with the humidity still in the area, heat indices will approach 110- 115 degrees. The heat does not appear to last into Wednesday as mid- level energy rounding the ridge axis pushes a surface boundary across the area Tuesday evening, shifting winds to the northwest and increasing precipitation chances across the area. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1214 PM CDT Thu Jun 20 2024 VFR TAFs will persist through the period at all sites with light winds and scattered diurnal cu. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Griesemer AVIATION...Griesemer