Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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286 FXUS63 KTOP 210957 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 457 AM CDT Sat Sep 21 2024 .KEY MESSAGES... - Scattered showers and storms early, then becoming widespread late today into late Sunday. - Minor severe weather potential north this afternoon and southeast Sunday afternoon. - Very warm today, much cooler Sunday into next week. && .DISCUSSION... Issued at 243 AM CDT Sat Sep 21 2024 Scattered showers and a few thunderstorms had redeveloped over central Kansas overnight and should continue through the early morning as warm-air advection slowly wanes. MUCAPE of less than 500 J/kg should keep this activity meager. Much of the daytime should be dry until a mid-level speed max ejects northeast from the southwest CONUS upper wave and a cold front sinks southeast into northeast Kansas in the late afternoon. Convection is more likely with the former item and may move into the frontal zone before updrafts become established along it. Along with mid-level lapse rates around 6 C/km and deep layer shear less than 30 knots, severe weather potential with the front is low. High temperatures should again reach the 90s for much of the area despite considerable mid-level cloud though still 5 to 15 degrees below record highs. Periods of precipitation are expected tonight into Sunday evening as the upper trough crosses the central Plains. Precipitable water values reach around 2" tonight when the models agree that the heavier amounts are likely, though NBM probabilities of over 1" in 6 hours are less than 50 percent, and the NBM 95th percentile for 6- hour precipitation is around 1.6" which is 1" below even 1-hour flash flood guidance with most places seeing little precipitation recently. This keeps the flooding threat low. The cold front moves through tonight into early Sunday afternoon. Shear and instability again look rather limited by this point Sunday for severe weather concerns. Considerable precipitation and cloud should keep highs in the 60s to lower 70s, 5 to 10 degrees above record coldest highs. SREF and NBM temperature spreads are in the 5 to 10 F range however. A few showers could linger into Monday morning until the trough exits, but much of the coming week appears dry with temperatures close to normal with general ridging over the High Plains and troughing to the east. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 457 AM CDT Sat Sep 21 2024 Scattered high-based showers and perhaps a few thunderstorms should be becoming more isolated through 16Z. Impacts with these should be minor. More robust and consistent convection is anticipated from late afternoon through the remainder of the forecast. TS may be more the exception than the rule, however ceilings will drop to MVFR to IFR near the end of this forecast behind a significant cold front. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Poage AVIATION...Poage