384 FXUS64 KTSA 032321 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 621 PM CDT Sat Apr 3 2021 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. VFR conditions will prevail through the period, with a stratocu deck likely spreading northward across eastern OK after 12z Sunday. Ceilings should remain above 3000 feet. Will also see locally reduced visibility in the 4-6SM range early this evening with numerous fires ongoing. && .PREV DISCUSSION... /Issued 150 PM CDT Sat Apr 3 2021/ DISCUSSION... Mid level heights will continue to rise this afternoon and evening as a broad mid level ridge moves in allowing for continued dry and warm conditions. This ridge will weaken some on Monday in response to an upper level storm expected to traverse the central plains Tuesday into Wednesday which will bring us chances for some showers and storms by mid week with a few severe storms possible Wednesday. Past Wednesday model spread increases greatly with overall confidence in the forecast decreasing. Fire weather will be the main concern for the next several days as dry, windy, and warm conditions prevail through at least the early part of the upcoming work week. Moisture return is underway across the area this afternoon with more noticeable values across our western tier of counties and especially as you go further westward into central Oklahoma where dew points are well into the 40s to near 50 along the Red River. The increase in moisture today along with slightly lower wind speeds thanks to a small relaxation of the surface pressure gradient have all allowed for slightly lower fire weather conditions as compared to yesterday but spread rates of Enhanced to border line Near Critical are likely being observed at this time, mainly across portions of northeast Oklahoma. Conditions will improve quickly tonight as winds decrease and slow but steady moisture return continues. Moisture return will become more prominent through the day Sunday with dew points largely surging into the 50s by the afternoon. With winds largely expected to be about the same as today, the fire weather threat will decrease some but will continue to be locally elevated across parts of northeast Oklahoma. Monday and Tuesday will see winds and fire weather concerns increase as the next storm system approaches. Despite dew points well into the 50s both days, temperatures are expected to be rather warm (generally in the mid to upper 70s) which will tend to reduce RH values in the 40 to 50% range Monday with slightly higher minimum RH values for Tuesday. The main driving factor for elevated fire weather concerns will be the winds which are forecast to gust between 20 to 30mph Monday with 25 to near 40mph gusts expected Tuesday. An RFD will likely be needed both of these days with spread rates in the near critical category for parts of NE OK. Our focus then shifts to the shower/storm threat Tuesday evening into Wednesday. The majority of guidance is in fairly good agreement when it comes to the track of the upper level low with both the GFS and ECMWF deterministic models having the low moving across Kansas through mid week. This is a little further south than previous runs thus will likely reduce our highs a little bit through mid week with temps in the 80s looking less likely. With that said, the models are also in fairly good agreement with a Pacific front/dry line pushing through Oklahoma and Arkansas on Wednesday. With ample shear, instability, and forcing from this cold front, expect showers and thunderstorms to develop along the front Wednesday with a noticeable increase in coverage and intensity by Wednesday afternoon across the eastern half of the CWA. At least a few strong to severe storms seems very possible. Thursday into the following weekend will likely be quiet as the upper low continues to move east or northeast out of the region. Thursday is also the day when confidence tanks due to a lack of run to run consistency. Violin plots of high temperatures to end the upcoming work week also support this idea with a fairly wide range of temperatures possible. Opted to go with the warmer guidance (NBM is leaning toward the warmer guidance as well) as there is some indication that a small amount of mid level riding in the wake of the upper storm system could allow for our warmer temperatures to continue into next weekend. Snider && .PRELIMINARY POINT TEMPS/POPS... TUL 50 76 56 78 / 0 0 0 0 FSM 44 74 52 77 / 0 0 0 0 MLC 51 73 54 77 / 0 0 0 0 BVO 50 77 54 78 / 0 0 0 0 FYV 44 73 49 74 / 0 0 0 0 BYV 44 73 51 74 / 0 0 0 0 MKO 47 73 54 76 / 0 0 0 0 MIO 47 74 53 75 / 0 0 0 0 F10 50 75 54 78 / 0 0 0 0 HHW 52 71 52 76 / 0 0 0 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ AVIATION.....14