200 FXUS64 KTSA 010518 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 1218 AM CDT Sun Aug 1 2021 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. Sct showers/storms associated with a cold front impacting far NE OK early in the period with brief MVFR vsbys in -TSRA. Activity is expected to wane by 10z-14Z with additional scattered development along the boundary during the afternoon across SE OK/WC AR. Will carry prob groups during the afternoon at KMLC/KFSM. Outside of thunder during the valid period, VFR elements will prevail at all sites. && .PREV DISCUSSION... /Issued 1020 PM CDT Sat Jul 31 2021/ DISCUSSION... Cold front/outflow boundary is pushing south across northeast Oklahoma and far northwest Arkansas at this time. Showers and thunderstorms have pushed south into the far northwest part of the forecast area, and scattered showers and storms will continue overnight mainly to the north of the boundary. Have raised pops some between now and 06Z based on current conditions, and have also lowered overnight lows a bit in northeast Oklahoma. Update on the way. PREV DISCUSSION... /Issued 624 PM CDT Sat Jul 31 2021/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. VFR conditions prevail currently across eastern Oklahoma and western Arkansas and that will likely remain the case for much of the valid period. However, isolated to scattered showers and storms will impact area sites later tonight and into Sunday as a cold front works through the area. PREV DISCUSSION... /Issued 216 PM CDT Sat Jul 31 2021/ DISCUSSION... This will be the last hot and humid day for a little while for most of the region with highs topping out near 100 and heat index values expected to range from 105-113 degrees through the rest of the afternoon. Relief is on the way though in the form of a cold front currently situated across central Kansas that will continue to slowly sag southward this afternoon and evening into northeastern Oklahoma. Scattered showers and thunderstorms are expected to develop this afternoon along the frontal boundary in Kansas and move southeast, possibly into far northeast Oklahoma by this evening. A few storms could be strong to severe this evening along the OK/KS border, however, minimal bulk shear and loss of diurnal heating as the sun goes down will limit overall severe potential for our forecast area. Still a few strong wind gusts will be possible with some of the strongest storms along the border. Widely scattered thunderstorms should continue along and just behind the boundary overnight tonight into tomorrow morning across northeast Oklahoma and northwest Arkansas. High PWats near 2" will lead to efficient, heavy rainfall within storms, but lack of coverage expected should keep any heavy rain/flooding concerns very localized. Cloud cover and areas of rain will keep temperatures down across most of the area, though the main surge surge of cooler/drier air won't arrive until Sunday night, so it will still feel quite muggy tomorrow afternoon especially where the sun peaks through. Ahead of the front in far southeast Oklahoma, heat index values are once again expected to reach and exceed 105 during the afternoon hours before the front and rain chances arrive. Therefore have issued another Heat Advisory for those areas tomorrow. As the front drifts south and east throughout the day tomorrow, increasing surface instability ahead of the front in southeast Oklahoma and west central Arkansas will once again pose a marginal severe wind threat with storms ahead of the boundary tomorrow afternoon and early evening. The front should push south of the forecast area by Sunday night. A secondary shortwave will move through the area Sunday night into Monday morning which could enhance precipitation along and behind the boundary causing storm chances to linger into Monday morning across far southeastern Oklahoma. After tomorrow, much cooler and drier air will filter into the region for the next several days bringing a welcome break to the summertime heat of the past week. Highs will mainly be in the 80s with lower humidity through the middle of next week. Mid level flow will remain amplified with persistent northwesterly flow over our area. A couple of weak shortwave will traverse the main flow and an afternoon storm or two will be possible Tuesday through Thursday, but coverage looks to very minimal at best. Upper ridge tries to nose back into the area by the end of next week, bringing with it a return to more seasonable heat for early August. Next best chance for rain could arrive by next Sunday though it looks to remain mostly dry for much of the next week. Bowlan && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Heat Advisory from noon today to 7 PM CDT this evening for OKZ049-053. AR...None. && $$ AVIATION.....23