FXUS63 KTOP 040509 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 1209 AM CDT Mon May 4 2026 .KEY MESSAGES... - Warm this afternoon and tomorrow ahead of the next frontal system, with highs in the upper 70s to mid 80s. - Storm chances increase late Monday afternoon and evening. A few storms could be severe with mainly a large hail with damaging winds threat. - Cooler overall mid to late week with low precipitation chances through Wednesday. - WPC clusters increasingly favor a building western ridge, with 80s likely returning by next weekend into early next week. && .DISCUSSION... Issued at 226 PM CDT Sun May 3 2026 A deep upper low remains anchored over eastern Canada with its trough working off the East Coast. Northwest flow extends into the northern Plains beneath a high-amplitude Pacific ridge into western Canada. A cutoff low persists offshore of California with a subtropical moisture plume streaming over Baja into the southern Plains. At the surface, a weak cold front sags into the region, with drier air along the KS/NE border and shallow but better- quality moisture working north from eastern TX into southeastern KS. Focus through the short term is on Monday afternoon and evening. NBM deterministic highs climb into the lower-to-mid 80s Monday with notably wider spread heading into the convective period and the approach of the frontal boundary from north to south across the area. Dewpoints climb into the upper 50s to lower 60s by Monday afternoon, with moisture return depth as the central question. The next frontal system has trended slower across ECMWF, GFS, NAM, and Canadian solutions as upper-level forcing remains displaced northeast of the area. This may compress the favored window for storm development during peak heating and elevates nocturnal stabilization as a real limiting factor further into the evening. The NAM has trended more strongly capped with somewhat disorganized hodographs and marginal mid-level shear. The GFS is slightly less capped late afternoon but remains stout enough to keep initiation conditional. Cap strength remains the central forecast challenge. SPC has eastern portions of the CWA in a Marginal Risk for Monday into Monday night. If storms form, steep mid-level lapse rates and around 35-40 knots of effective shear may support a few severe storms, with large hail as the primary hazard and damaging winds also possible into the evening. The slower system trends may shorten the storm window, with mesoscale details still depending on cap erosion, moisture depth, and frontal timing as previously hinted at. Probabilistic guidance has trended upward this cycle. CSU-MLP Day 2 hail probabilities max near 23 percent across eastern KS into MO (up from 15 percent yesterday), with wind near 14 percent displaced east-southeast and tornado signal minimal. NBM 12-hour thunder probabilities peak near 60 percent across the CWA. Behind the front Monday night, northwest flow takes over with a broad open wave rotating through midweek. This wave keeps low chances for precipitation in the forecast from midday Tuesday through Wednesday evening before drier conditions take hold late week. WPC cluster guidance increasingly favors a building western ridge into the latter half of the week, with the dominant cluster strengthening from Day 7 through Day 9 to anomalies of +50 to +75 meters across the central CONUS. Roughly three-quarters of ensemble members support warmer and drier conditions returning, with NBM highs into the 80s by next weekend into early next week. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1208 AM CDT Mon May 4 2026 VFR TAFs persist at all sites with low level wind shear becoming evident over the first several hours of the period. Surface winds should increase enough around the late morning hours for wind shear to get taken out of TAFs with the remainder of the period seeing light southwesterly winds and mid cloud filtering in from the west. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Drake AVIATION...Griesemer