Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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289 FXUS63 KTOP 061944 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 244 PM CDT Sat Jul 6 2024 .KEY MESSAGES... - A few storms possible late this afternoon through the evening mainly over north central into portions of northeastern Kansas - damaging wind the primary threat with hail also a concern. - Heavy rainfall possible Sunday morning through Sunday night as another storm system moves through the area. - Trending drier after Monday and warming up into next weekend into the 90s. && .DISCUSSION... Issued at 243 PM CDT Sat Jul 6 2024 The current UA pattern across the CONUS features a broad cyclonic flow regime from the New England region curving down into the central Plains back up into western Canada. A sharp ridge is in place along the Pacific coastline with a strong dome of high pressure over the California and northern Baja regions. Meanwhile, tropical moisture is over the deep south with Tropical Storm Beryl spinning over the western Gulf of Mexico. An area of surface low pressure has been deepening into this afternoon over southwestern Nebraska with at least one intense supercell along an associated warm frontal boundary extending generally along I-80 through Nebraska. The associated cold front extends through northwestern Kansas. This afternoon through this evening, a weak upper mid level shortwave continues to work across Nebraska with the best forcing for ascent mostly to the north of the local area. This should keep the highest chances for storms to remain through Nebraska along the warm front. Can`t rule out a storm or two remaining severe as they move into the area and tend to weaken overall due to a lack of steep midlevel lapse rates which appear to drop off significantly further away from the shortwave. Additionally, a drier profile is in place heading from KLBF to the southeast into KTOP per UA analysis. The LLJ doesn`t intensify until this evening which will be better focused over southwestern into portions of central Kansas where the strongest convergence takes place and thus the better quality moist advection in the low levels which should fuel better storm potential generally southwest of the area. Thus, have lowered POPs overall tonight to focus over north central and northeastern areas which appear to have about a 30 percent chance for storms if the current storms over south central Nebraska and perhaps western Kansas can develop sufficient cold pools to see further development along the outflow boundaries from the parent storms. Confidence is too low to raise POPs too far into the area for this evening. Storms that do move into the area this afternoon/evening appear to pose mostly a damaging wind threat but can`t rule out hail as well with freezing level heights around 11kft. Into Sunday morning, could see broader precip shield develop in advance of another shortwave digging into western KS and translating east through the day. Best chances for heavy rainfall could still be just into central and east central areas as theta-e advection increases in advance of the shortwave. Could see a few areas experience flooding concerns with with convective influences and PW values around 2 inches and flash flood guidance for 1-3hr rainfall rates around 2-3 inches. The overall pattern begins to change into Tuesday with the western ridge broadening and the Westerlies retreating to the north again. This will allow for a drying trend to take shape with warming temperatures into the 90s by Friday and next weekend. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1217 PM CDT Sat Jul 6 2024 A VFR forecast is anticipated to prevail for now with overnight clouds increasing across the area so any radiational cooling effect may be limited. Showers and storms may also stay to the north and southwest of the terminals so certainty remains too low to include mention other than mid clouds for the overnight period. There may be more widespread precipitation develop into the morning hours but confidence is still too low for the 18-24 hrs out. Expecting a LLJ to develop around midnight through sunrise which looks to generally weaken only a few hours after developing. Marginal WS conditions expected briefly around FL015. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Drake AVIATION...Drake