567 FXUS64 KTSA 121749 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 1249 PM CDT Thu Aug 12 2021 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. High clouds will continue to stream into the area this afternoon and evening while cu developing across E OK and NW AR will eventually diminish once the sun sets. Gusty winds (around 20kts at times) will also diminish once the sun sets as well. This evening and overnight will see a gradual increase in clouds as a storm system approaches the area from the north. A line of storms will push southward across E KS through the overnight hours. There is a considerable amount of uncertainty in the exact coverage of showers/storms and timing and if the line will hold together. With that said, there will likely be some activity along an outflow boundary as it pushes through but pinpointing a time or location is difficult at this time. Opted to go with a PROB30 for -TSRA tomorrow morning for most sites given the relatively low confidence. Outside of any shower/storm activity, expect VFR conditions to prevail. Snider && .PREV DISCUSSION... /Issued 1015 AM CDT Thu Aug 12 2021/ ..UPDATE... DISCUSSION... A more or less stagnant upper air pattern is leading to continued hot and humid conditions across the area. Temperatures are once again expected to soar into the mid to upper 90s. In terms of the dew points, there is some uncertainty as to how they will trend this afternoon. The latest guidance is in fairly good agreement with dew points dropping some but the latest HRRR drops the dews off quite a bit this afternoon and appears to be a little too ambitious given the trends over the past few days. So far, there has not been noticeable mixing in the surface obs. With scattered to broken cloud cover today, that may help to keep dew points a little more elevated this afternoon. Long story short, no changes are currently planned to the going Heat Advisory. The highest heat indices (near 110) are still expected to occur over NE OK where moisture has been consistently slow to decrease. Luckily, relief is on the way in the form of a cold front and showers/storms that will approach the area late tonight into tomorrow before giving us cooler weather this weekend. In the mean time, elevated mid to upper level moisture well ahead of the front today (a weak 700mb and 850mb jet are present over the area) will allow for mid to high clouds to develop as is currently evidenced by the latest visible satellite. A noticeable max of 850mb moisture over W AR and far NE OK may allow for some isolated to scattered cu development later this afternoon in these areas. Overall, minor changes were made to the forecast to account for the latest trends. An update will be issued shortly. Snider && .PRELIMINARY POINT TEMPS/POPS... TUL 77 96 72 89 / 30 40 30 40 FSM 76 97 75 89 / 0 30 30 60 MLC 75 96 72 90 / 0 20 30 50 BVO 72 92 68 87 / 40 50 30 40 FYV 71 92 68 86 / 20 40 40 60 BYV 74 93 70 86 / 20 50 40 50 MKO 75 95 72 89 / 10 30 30 50 MIO 73 91 70 86 / 40 50 40 40 F10 75 97 71 89 / 10 30 30 50 HHW 75 96 74 92 / 0 20 20 60 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Heat Advisory until 8 PM CDT this evening for OKZ054>072-074-076. AR...Heat Advisory until 8 PM CDT this evening for ARZ001-002-010-011- 019-020-029. && $$ AVIATION.....21