663 FXUS64 KTSA 191755 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 1255 PM CDT Sun Apr 19 2020 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. The beginning of the TAF period will be quite busy for most locations. Thunderstorms are expected to develop within the next hour or 2 of writing. Storms are expected to impact southeast Oklahoma and northwest Arkansas with associated TAF sites expected to be affected. The TAF sites include KMLC and all of our NW AR TAF sites. KTUL, KRVS,and KBVO, will likely not see thunderstorms this afternoon given the latest guidance and limited instability but there continues to be a low chance for a brief shower. The strongest thunderstorms could be seen over KMLC and KFSM this afternoon with the main threat being large hail with severe wind gusts possible. Thunderstorms will quickly move out of the area by early this evening. Tonight will feature clearing skies for most TAF sites and light winds leading to VFR conditions through most of the night. Given that the soil is expected to moist from today's rains, areas of fog will be possible. Valleys and locations near bodies of water will see the greatest potential for fog late tonight into tomorrow morning. Our NW AR TAF sites will likely see the best potential for lowered visibilites given light winds, mostly clear skies, and short term guidance has been showing signal for the past several runs adding to confidence in the forecast. Our far NW AR TAF sites (excluding KFSM) will also see a greater likelihood of MVFR to IFR ceilings late tonight into tomorrow morning as well. && .PREV DISCUSSION... /Issued 1019 AM CDT Sun Apr 19 2020/ ..UPDATE... DISCUSSION... A couple of thunderstorms are ongoing across portions of Adair and Washington (AR) counties this morning. These cells have pulsed up a little, enough so to produce pea size hail near Tahlequah, but over these thunderstorms are staying below severe limits which should be the continued trend for at least the next few hours given limited instability thanks to a thick stratus deck. This afternoon will be a little more interesting. Strong to severe storms will be possible for much of the area with the greatest chances for severe weather located over southeast Oklahoma and west-central Arkansas. This area will be closer to the low pressure center and the attendant warm front. Locations along and south of the warm front will see the best chances for severe weather due to better shear (likely characterized by rotating updrafts) and better instability. Pockets of clearing will be possible across southeast Oklahoma this afternoon which could locally elevate the severe threat. The question still remains, how far north will this warm front move? At the moment is appears the best answer to that question is points just to the south and southeast of a line extending from about McAlester to Fort Smith. Thunderstorms in the aforementioned region will be capable of producing golf ball size hail with a lower threat for damaging wind gusts. A warm front farther north would promote more surface based storms and thus a better chance for damaging wind gusts. Locations to the north of the aforementioned area will likely exhibit less instability and storms will likely be more elevated in nature. Regardless, a few supercells are expected this afternoon across parts of SE OK and W-central AR. Snider && .PRELIMINARY POINT TEMPS/POPS... TUL 46 75 49 75 / 0 0 0 10 FSM 46 75 50 78 / 20 0 0 10 MLC 48 74 51 78 / 10 0 10 10 BVO 44 75 47 74 / 0 10 0 0 FYV 44 72 48 74 / 20 0 10 0 BYV 43 71 47 72 / 20 10 10 0 MKO 44 72 49 75 / 10 0 0 10 MIO 42 72 45 71 / 0 10 10 0 F10 46 74 51 76 / 10 0 10 10 HHW 51 73 53 77 / 10 0 10 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ AVIATION.....21