296 FXUS63 KTOP 140940 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 440 AM CDT Wed Aug 14 2019 .SHORT TERM...(Today and tonight) Issued at 430 AM CDT Wed Aug 14 2019 Not expecting much in the way of sensible weather today outside of some very isolated showers or a morning thunderstorm mainly north of I-70 over north central Kansas. Storm chances increase into the overnight period and during the morning Thursday. Currently, mostly zonal to slight northwest flow component in place across the area with a surface ridging maintained across the area extending into southeastern Kansas. This stable and relatively dry airmass has caused prior convection this evening to essentially erode to just a few isolated showers now over southeastern Kansas. With any significant LLJ disturbed by this earlier convection and ongoing convection over western KS, uncertain how much moisture return may be available over north central areas early this morning. This will probably greatly limit any resultant isentropic ascent that can develop over north central Kansas early this morning on the western flank of the surface ridge. But, nonetheless, some short- term guidance maintains early morning showers as a possibility. Should these develop, coverage should be very limited and short lived. Today should remain dry during the day with high clouds drifting over the area from convective debris resulting from tonight convection now ongoing over eastern Colorado through southwestern Kansas. Highs top out in the mid 80s with a heat index remaining acceptable into the upper 80s thanks to the overall lower dewpoints into the mid 60s. Tonight, it appears that consistency amongst guidance continues to hint at a moderately strong LLJ setting up across western into central Kansas. As late afternoon convection fires over the high plains, expect a slow evolution for storms to congeal into an MCS that can become forward propagating into the area. There is still timing spread amongst guidance but the common theme is a later than previously thought arrival time for overnight convection as the LLJ is slower to veer. Thus, not expecting any complex of storms to arrive into the area until well after midnight. With the LLJ not reaching peak intensity until early Thursday morning, it appears most guidance doesn't even advance storms into the area perhaps until after sunrise. With the lack of significant upper forcing and the best mid level lapse rates back into Nebraska, thinking that storms may run into a more stable environment into northeast Kansas and eventually weaken as they propagate through the area. A damaging wind threat therefore should be focused over north central Kansas into portions of northeast Kansas before more stratiform remnants eventually decay across the area. Still uncertain from here how the afternoon will evolve with outflow boundaries, etc. But there could be additional storms into the late afternoon and early evening as recovery of atmosphere takes place. This would probably give increasing concern to some areas seeing repeated heavy rain with high theta-e air in place and high PW values approaching 2 inches. .LONG TERM...(Thursday through Tuesday) Issued at 430 AM CDT Wed Aug 14 2019 A more uncertain mid to long range forecast period hinges on the aforementioned convection at least in part and the next round of high plains convection that develops over western Nebraska. Current indications are that a more northerly track to this MCS may impact southeastern Nebraska before advancing into extreme northeastern Kansas with the associated severe threat of mainly damaging wind and heavy rainfall. With a warm front draped across the area into Friday, there could be opportunity for afternoon convection as well but this appears too uncertain at this time to have much confidence in any afternoon development. However, if inhibition can be overcome, then sufficient shear and instability should allow for more organized storm potential. The concern would be with backed winds along the warm front and increased SRH. Couldn't rule out a tornado threat if that happens. With a persistent slightly northwest flow pattern holding, Late Friday into Saturday morning could see yet another late night storm system move into the area. It appears better forcing with an amplified Pacific trough should help foster another MCS into Saturday morning. Again the repeated rounds of storms could lead to flash flooding concerns . && .AVIATION...(For the 06Z TAFS through 06Z Thursday) Issued at 1123 PM CDT Tue Aug 13 2019 Chances for elevated storms redeveloping overnight appear to be low as the 00Z NAM has backed off on this idea and the 00Z GFS maintains a dry forecast. Thinking is the MCS moving into northern OK has disrupted the mid level flow such that the isentropic lift progged in earlier runs will not be as strong. So think VFR conditions are likely to prevail with surface ridging providing relatively dryer air in low levels. With no obvious forcing will keep the forecast dry going into Wednesday evening. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Drake LONG TERM...Drake AVIATION...Wolters