Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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711 FXUS63 KTOP 052240 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 540 PM CDT Sun May 5 2024 .KEY MESSAGES... -Light rain tapers off over eastern KS this afternoon. Isolated pockets of fog could develop tonight. -A dynamic system is still on track to bring severe weather back to the area tomorrow afternoon and evening. Very large hail, strong winds and tornadoes will all be possible. -Drier weather is then expected mid and late week. && .UPDATE... Issued at 540 PM CDT Sun May 5 2024 Models show a continued low level warm air advection pattern through the night with some indication of isentropic upglide, at least off an on, into late Monday morning. Forecast soundings also show some modest lift within the stratus deck. So have added some patchy drizzle to the forecast. && .DISCUSSION... Issued at 254 PM CDT Sun May 5 2024 This afternoon, there are two systems of importance to note - a shortwave trough over Arkansas, slowly moving northeast within the mid-level flow, and a stronger system over the western CONUS, evident on water vapor imagery by a tight cyclonic circulation centered near the OR/ID stateline. Light rain associated with the first system has slowly moved northward with time today. Light QPF is forecast across east-central KS into mid-afternoon before rain tapers off and moves east of the area. Cloud cover and rain today are keeping temperatures in the upper 50s and low 60s. Stratus will remain in place tonight with models also showing some signal for fog development, mainly were rain fell today. If winds are able to go light (less than 5 mph), fog will become more likely. For now, however, the extent of fog is expected to be limited. The western CONUS system still looks concerning regarding the severe weather potential in central and eastern KS tomorrow. Surface low pressure will deepen and move out over the northern high plains late morning as the mid-level negative tilt trough axis approaches that region. Instability may be slow to increase in eastern KS through the midday hours, given lingering low cloud cover. However, strong low level moisture transport into the area will increase buoyancy while mid level lapse rates steepen, resulting in between 1500-2500 J/kg of MLCAPE ahead of the dryline tomorrow afternoon. Expected shear parameters remain impressive, with forecast sounding analysis showing near 250 m2/s2 of effective inflow layer SRH and around 50 kts of effective bulk shear. CAMs are in good agreement with development occurring along the cold front/dryline in central KS early to mid afternoon with storms forming into a line or broken line segment and quickly advancing eastward into the evening hours. If this exact scenario plays out, very large hail and tornadoes will be the main concerns initially, with an increasing wind and QLCS tornado threat as the evening progresses. Evolution of storm mode remains somewhat in question, but the bottom line is that all modes of severe weather could again occur as our active spring season continues tomorrow. Storms moves east of the area Monday night, leaving dry weather in the forecast for Tuesday. However, another shortwave looks to develop and move around the main system that will then be sitting north of the area Tuesday night and early Wednesday. That could generate a few showers or storms early Wednesday. A severe weather threat could develop ahead of that secondary boundary, but will likely be southeast of the area, mainly in the Ozarks. A stretch of dry and seasonable weather is then expected through the remainder of the workweek. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 540 PM CDT Sun May 5 2024 Conditions are expected to deteriorate this evening as low level moisture continues to advect north into cooler air. CIGS are forecast to lower below 1 KFT with the potential for some patchy drizzle. CIGS should improve gradually in the afternoon, but think it is unlikely for the boundary layer moisture to mix out completely and have some MVFR CIGS well into the afternoon. +TS are likely to impact the terminals late in the period with most if not all the CAMs showing a line of TS moving west to east between 21Z and 03Z. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Wolters DISCUSSION...Teefey AVIATION...Wolters