725 FXUS64 KTSA 122344 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 644 PM CDT Thu Apr 12 2018 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. Gusty southerly winds and few/scattered mid and high clouds should remain common into the overnight hours tonight. Late tonight and into Friday morning...MVFR ceilings look to develop and spread across the CWA within the gusty winds ahead of a dryline approaching from the west. MVFR ceilings look to remain common through the TAF period for Northwest Arkansas. Dryline looks to pass Eastern Oklahoma TAF sites Friday afternoon with clearing skies and continued gusty southwesterly winds. Small chances for showers/storms during the morning hours Friday over the CWA with increasing chances for Southeast Oklahoma and Northwest Arkansas Friday afternoon ahead of the dryline. Will continue with Prob30 groups for timing. && .PREV DISCUSSION... /Issued 310 PM CDT Thu Apr 12 2018/ DISCUSSION... Gusty south winds continue this afternoon as the Lee surface cyclone continues to deepen. Fire weather conditions have been tempered some by improved moisture, with surface dewpoints rebounding to 55-60F and RH values remaining above 50 percent. Exception is across parts of Osage/Pawnee counties where drier air resides and existing fires continue to be aggravated. The strong low-level jet will keep surface winds gusty into the overnight hours, and may need to extend the wind advisory for the remainder of the night. A strong cap will remain in place through tonight, although still expecting some elevated convection to develop late tonight into Friday morning as the persistent warm-air advection eventually erodes the cap. Followed the 12Z NAM fairly closely for the dry line progression tomorrow afternoon, which offers a compromise between the faster GFS and slower ECMWF. As such, quickly deteriorating fire weather conditions are expected west of U.S. 75 later Friday afternoon, with RH values dipping to around 20 percent along with gusty southwesterly winds. Will upgrade the existing Fire Weather Watch to a Red Flag Warning. Convective evolution certainly isn't clear cut for tomorrow afternoon, with a few CAM solutions suggesting initial development as early as 18-19Z as the dry line moves into eastern OK. The bulk of the solutions, however, hold off on significant development until 21Z and beyond mainly east of U.S. 75. CAMs also suggest that the activity may initially be quite scattered, with storms eventually growing upscale as they exit our forecast area by mid-evening. Regardless, strongly sheared wind profiles and MU CAPE values exceeding 2000 J/KG will support strong/severe storms with all modes of severe weather possible. Breezy and cool weather conditions will prevail through the weekend in the wake of the frontal passage. Will likely need freeze headlines for Sunday and Monday mornings as temps dip below freezing for a few hours, especially north of I-40. Milder weather expected for early next week with a weak cold front moving through by Wednesday. && .PRELIMINARY POINT TEMPS/POPS... TUL 69 80 39 51 / 20 40 10 10 FSM 64 78 45 56 / 20 60 50 10 MLC 69 79 41 56 / 30 40 20 0 BVO 69 82 39 50 / 20 40 10 10 FYV 63 74 40 51 / 10 60 50 10 BYV 63 74 44 51 / 10 60 60 10 MKO 65 78 41 53 / 20 40 20 10 MIO 66 79 39 49 / 20 50 30 10 F10 67 79 40 53 / 20 30 10 10 HHW 65 78 45 57 / 30 60 30 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Wind Advisory until 1 AM CDT Friday for OKZ054>071-073. Red Flag Warning from 1 PM to 10 PM CDT Friday for OKZ054-059- 064-065. AR...Wind Advisory until 1 AM CDT Friday for ARZ001-002-010-011. && $$ AVIATION.....20