Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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554 FXUS63 KTOP 111734 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 1234 PM CDT Sat May 11 2024 .KEY MESSAGES... - Rain chances increase through the day Sunday into the 70 to 90 percent range by the evening. - Showers may be more hit or miss in the morning and early afternoon Sunday. - Another system expected to bring chances for showers and storms Wednesday and Thursday. && .DISCUSSION... Issued at 234 AM CDT Sat May 11 2024 07Z water vapor imagery showed a closed low still over the southwestern U.S. while a shortwave trough dug southeast through the Great Lakes. Surface obs continued to show high pressure over the central and southern plains with the higher dewpoint temps along the gulf coast. There remains good agreement among the operational models for the low out west to phase in with the mean westerlies and propagate across the plains. The better forcing with this wave looks to move across the forecast area late in the afternoon Sunday and Sunday night. So this is when the forecast has categorical POPs. Models still show dewpoints increasing into the middle 50s and around 60 by Sunday afternoon. This should lead to some modest CAPE between 500 and 1000 J/kg. And bulk shear is progged to be relatively week between 15KT and 30KT. So organized severe weather remains low, or less than 5 percent. Depending on how much sun there is, it is not out of the question for some pockets of the higher instability and perhaps some strong storms. Think activity during the morning and early afternoon may be more hit and miss since there doesn`t appear to be a strong focus or boundary for precip to develop around. POPs remain high through Monday as the upper wave passes overhead. Forcing for vertical motion is expected to pass to the east of the forecast area Monday evening which should bring an end to the precip. The next mid and upper level wave is on track to move through the central plains Wednesday and Thursday. The overall idea from the deterministic solutions is similar but there continues to be differences in the strength of the system and the NBM shows higher spread in the potential outcome by Thursday. Because of this continued uncertainty, POPs remain in the 30 to 50 percent range. And the GFS forecasts of CAPE and bulk shear remain rather marginal for an organized severe risk. Temps through the extended look to be mainly driven by insolation and/or cloud cover since there is no strong signal of temperature advection. In general highs look to remain in the 70s to lower 80s with cooler temps forecast when clouds and rain are probable. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1231 PM CDT Sat May 11 2024 Expect VFR conditions for the next 24 hours. Westerly winds under 10 KTS will become more southwesterly this evening and through the night. Highs and mid clouds will increase late Tonight through Monday morning. There could be a few rainshowers around the terminal during the mid and late morning hours. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Wolters AVIATION...Gargan