934 FXUS64 KTSA 280503 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 1203 AM CDT Wed Jul 28 2021 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. Patchy fog may provide brief visibility restrictions early this morning primarily across far NW AR, otherwise VFR conditions expected with very low coverage of afternoon storms. && .PREV DISCUSSION... /Issued 940 PM CDT Tue Jul 27 2021/ DISCUSSION... Diurnal convection has pretty much ended across our forecast area this evening, and fair but warm conditions should prevail the remainder of the night, as the air mass stabilizes and mid level heights rise. Earlier forecast update cleaned up today's heat headlines and thunderstorm chances that we continued into the early evening, otherwise forecast is on track with overnight temperatures likely falling to readings close to those of this morning with little air mass change. Another hot day in store tomorrow with less chances of rain as mid level ridge builds over the Southern Plains, and deeper moisture continues to be pushed southward. PREV DISCUSSION... /Issued 626 PM CDT Tue Jul 27 2021/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. Isolated showers and storms across eastern OK will dissipate over the next few hours. Outside of some localized fog across parts of northwest AR, expect VFR conditions to prevail. PREV DISCUSSION... /Issued 319 PM CDT Tue Jul 27 2021/ DISCUSSION... Hot and humid conditions continued across much of Eastern Oklahoma and Northwest Arkansas this afternoon with dewpoints in the 70s and temps in the 90s common. These conditions were creating heat index values in the 105 to 111 deg range over much of the CWA, especially over locations not currently receiving rainfall. Thus...will allow for current heat headlines to continue. Isolated to scattered showers and thunderstorms had developed once again with the daytime heating. The bulk of this activity was ongoing over Southeast Oklahoma while more isolated activity was observed over parts of Northeast Oklahoma and Northwest Arkansas. Moderate to steep low level lapse rates will aid in convection having the potential for gusty to strong winds reaching the surface. Very weak shear values should limit hail production. Instability weakens with the loss of daytime heating and thus...ongoing activity should dissipate by mid evening. Dome of high pressure centered currently over the Central Plains is progged to expand over the Southern Plains this week with a return of southerly low level flow by Thursday. In response...hot and humid conditions are forecast to continue through the week with afternoon temperatures each afternoon at or slightly warmer compared to the day before. Surface dewpoints are still expected to be slightly less...though still remaining in the 70s...for the rest of this week. This will create heat index values of 105 to around 110 deg each afternoon and as such have expanded the heat advisory to include Wednesday afternoon. Depending on the dewpoints react Wednesday...a portion of this advisory could be upgraded to an excessive heat warning. Also...with the warming temps...the rest of Northwest Arkansas could get included in the heat headlines at some point this week. Over the weekend...the ridge of high pressure is progged to become more amplified from north to south across the Western CONUS as a longwave trof axis drops southeast into the Eastern CONUS. This should put the CWA on the far eastern fringe of the ridge and the western periphery of the long wave trof. In response...Saturday looks to be the warmest day of the forecast period ahead of a cold front forecast to approach/move into the region from the northeast Sunday/Monday. High temps Saturday look to reach into the upper 90s to around 102 deg across the CWA. Shower and thunderstorm chances look to return as the cold front approaches Sunday and continue into Monday. With this late weekend system...some relief from the hot and humid conditions will be possible as highs early next week could drop back into the 80s. There continues to be uncertainty with how far the frontal boundary can push through the region. If it hangs up north of the CWA...then hot and humid conditions could continue. Will continue to monitor as latest data come in. && .PRELIMINARY POINT TEMPS/POPS... TUL 97 77 99 78 / 0 0 0 0 FSM 98 77 101 78 / 10 0 0 0 MLC 97 75 99 76 / 10 0 0 0 BVO 95 74 97 74 / 0 0 0 0 FYV 95 72 96 73 / 0 0 0 0 BYV 96 73 97 74 / 0 0 0 0 MKO 96 75 97 76 / 0 0 0 0 MIO 95 75 97 75 / 0 0 0 0 F10 97 76 98 76 / 0 0 0 0 HHW 96 76 97 77 / 10 0 0 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Heat Advisory from noon today to 8 PM CDT this evening for OKZ049-053>076. AR...Heat Advisory from noon today to 8 PM CDT this evening for ARZ019-020-029. && $$ AVIATION.....07