773 FXUS63 KTOP 241958 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 258 PM CDT Sat Mar 24 2018 .SHORT TERM...(This evening through Sunday) Issued at 258 PM CDT Sat Mar 24 2018 The upper low center is currently centered over Iowa this afternoon. The associated low stratus downstream of the wave has resulted in a blustery, cool afternoon over northeast Kansas. While clouds may attempt to break towards the Emporia area by late afternoon, the stratus is expected to fill back in overnight as the system exits eastward and ridging amplifies across the central plains. Low level flow veers towards the southwest after midnight as a poignant shortwave trough deepens over the west coast. A weak embedded vort max quickly lifts northeast through the mean flow towards central Kansas by Sunday morning. Forecast soundings have limited moisture to work with as much of the isentropic ascent is below 875 mb so confidence is not high for widespread precip to occur through Sunday morning. We are still not anticipating frozen precip in north central areas with all high resolution guidance depicting temps in the middle 30s by the onset. Have a slight chance for drizzle along and west of highway 75, with chances for scattered showers increasing during the afternoon and evening hours as lee cyclogenesis commences to the west as the upper system approaches. Persistent cloud cover and cool air advection from the east will limit highs once again to the upper 40s to lower 50s. .LONG TERM...(Sunday night through Saturday) Issued at 258 PM CDT Sat Mar 24 2018 Surface trough quickly deepens over the highs plains Sunday night as a stronger shortwave trough ejects into the central plains. Sfc dewpoints in the 50s, possibly 60, advects northward towards the CWA, while a stout 850 mb jet overruns a warm front bisecting the CWA west to east. Showers are likely with scattered thunderstorms expected after midnight. Steep midlevel lapse rates with 0-6 km bulk shear values in excess of 50 kts spell the potential for a few strong or low end severe storms. Profilers suggest a strong capping inversion layer throughout the day with convection initializing above this layer. Main hazards with these storms would be marginally severe hail and gusty winds. As the cold front tracks southeast through the CWA Monday afternoon, uncertainty increases as to if there will be any clearing and the possibility of destabilizing the capping inversion. Latest sweep of the model guidance leans more towards a slower trend in precipitation clearing eastward by late afternoon with the GFS being the more robust and slower with the front, increasing instability and initiating convection over the CWA. Most other guidance focuses the stronger, surface based convection towards southeast Kansas. Will maintain the chance for thunderstorms during the afternoon and early evening, however many factors still unclear in the severity and mode of convection, especially in the late afternoon. Post frontal showers linger through Tuesday morning before cool and gusty northwest air filters into the area, dropping temps from the upper 60s Monday to the lower 50s Tuesday. The elongated, slow moving shortwave trough is gradually phased with the northern stream series of waves, bringing additional shower chances Wednesday night and Thursday. The lack of strong temperature advection should keep temperatures fairly similar Wednesday onward with highs around 60 and overnight lows in the 30s. Much of the area unfortunately remains dry through Saturday. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) Issued at 1150 AM CDT Sat Mar 24 2018 MVFR stratus persists over terminals as the surface low translates eastward tonight. Monitoring trends at KMHK as the southern end of the stratus deck is anticipated to erode some, lifting ceilings to VFR aft 20Z. The MVFR stratus fills back in after 02Z as winds around 10 kts sustained veer from the north towards the east by 11Z. The next system is progged to bring scattered showers Sunday afternoon however confidence in location is too low to include at this time. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Prieto LONG TERM...Prieto AVIATION...Prieto