328 FXUS63 KTOP 162345 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 645 PM CDT Tue Jun 16 2020 ...Update to aviation forecast discussion... .SHORT TERM...(This evening through Wednesday) Issued at 330 PM CDT Tue Jun 16 2020 Overall quiet weather is forecast for tonight and Wednesday with continued warmth. The threat for a very isolated thunderstorm remains across far eastern Kansas for this afternoon along a very diffuse lower- tropospheric region of confluence and higher axis of theta-e air that follows the KS/MO border. Given the minimal changes in the kinematic and thermodynamic environment compared to yesterday, any storms that do form should behave similar to yesterday's convection east of the KC metro. The lack of any deep shear will result in short-lived updrafts with any threats for impactful weather limited both spatially and temporally. These storms dissipate with the loss of daytime insolation prior to sunset. Tonight will be quiet with clear skies under the blocking upper level ridge and lows once again falling into the lower 70s. Wednesday features somewhat stronger winds compared to today as a Front Range lee trough deepens ahead of an approaching Pacific NW trough. Diurnal CU are once again expected in the afternoon, but confidence in additional peak-heating storms is lower than today and not included at this time in the forecast; though the GFS and several HREF members do develop a stray thunderstorm. .LONG TERM...(Wednesday night through Tuesday) Issued at 330 PM CDT Tue Jun 16 2020 An active weather pattern sets up for the end of the week into the weekend with multiple rounds of storms possible. The axis of the longwave ridge finally begins sliding eastward on Thursday and shifts over the Appalachians by Sunday. In doing so, the upstream lee trough shifts eastward late Wednesday into Thursday, reaching central Kansas midday Thursday and laying out across the area for Friday. One notable shortwave rotates around the base of the longwave on Friday and results in the baroclinic zone lifting back northward for Saturday before a cold front sweeps through Saturday evening. Confidence in any severe potential is on the low side with either weak deep shear or the mean cloud-bearing flow oriented parallel to the forcing mechanism, resulting in rapid upscale growth to clusters or lines of convection. The warm sector environment will be characterized by modest SW flow/mid-level Pacific moisture and increasing return flow from the Gulf. This type of setup favors multiple rounds of heavy rainfall beginning late Thursday and continuing into Saturday, though the exact timing and locations of the heavier rain are uncertain. It is difficult to ascertain the risk for flash flooding given the dry antecedent conditions leading into this event and the likelihood of breaks between the precipitation. Confidence in the convective details beyond Saturday decreases rapidly as the longwave patterns of the GFS/EC diverge significantly. GEFS plumes do show a rather steady increase in run-total QPF through the weekend and early next week, but members vary substantially on the timing of when this rainfall takes place. Temperatures gradually moderate into the weekend with the increasing influence of convection, followed by a quick shot of dry Northern Plains air Saturday night on the backside of the cold front. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 645 PM CDT Tue Jun 16 2020 VFR conditions will persist through the period at KTOP/KFOE/KMHK with some high-based diurnal cumulus clouds developing Wednesday afternoon. Winds weaken this evening before southerly winds increase again tomorrow with gusts of 20-25 kts through Wed. afternoon. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Skow LONG TERM...Skow AVIATION...Flanagan