049 FXUS64 KTSA 061726 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 1226 PM CDT Sat Jun 6 2020 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. Scattered to locally broken cumulus clouds are expected around the Arkansas TAF sites, with a few cumulus developing around the Oklahoma sites. An isolated thunderstorm or two is possible this afternoon and early evening. The most favored areas for storm development will be near the higher terrain of northwest Arkansas and southeast Oklahoma. Any cell that forms would move toward the west at 10-15 knots. Strong gusty winds are likely in and around any storms. && .PREV DISCUSSION... /Issued 1101 AM CDT Sat Jun 6 2020/ ..UPDATE... DISCUSSION... We are adding a chance of thunder to parts of northwest Arkansas and northeast Oklahoma as the depth of the CAP has already become shallow in parts of these area and satellite images show convective clouds over parts of northwest Arkansas. It seems reasonable that a couple of storms should form this afternoon near the terrain of Crawford...Franklin...Madison and Washington Counties. If they form, they will move westerly at 10 to 15 knots and into parts of northeast Oklahoma. Additionally, old convective outflow is moving west across southwest Arkansas. From this process a little more lift may occur in southeast Oklahoma this afternoon. We will tweak the area previously forecast to have a chance of thunder in southeast Oklahoma and raise the POPs just a bit. Any storms that form should be dissipating by early evening. We adjusted dew points up a couple of degrees in parts of northwest Arkansas based on current trends. Temperatures are tracking near the current forecast. So the Heat Advisory area will not be adjusted at this time. While falling short of advisory levels in far northwest Arkansas, heat index values near 100 and light winds call for some caution there as well. PREV DISCUSSION... /Issued 234 AM CDT Sat Jun 6 2020/ DISCUSSION... A mostly quiet night is underway with a weakening thunderstorm complex grazing extreme southeast OK, and a few spotty areas of fog noted across eastern OK. Dewpoints have quickly recovered across parts of northeast OK over the past 24 hours, and expect lower/mid 70s readings to persist into the afternoon. No changes planned for the existing Heat Advisory. A few CAM solutions suggest some isolated afternoon convection across parts of southeast OK, and will maintain low PoPs for these locations. Hot/humid weather is expected again for Sunday, although another day of drying may help keep dewpoints a touch lower than today. TS Cristobal is expected to make landfall along the LA coast Sunday evening, and lift northward into central AR by Monday evening. Bands of showers with embedded thunderstorms will begin to impact parts of southeast OK into western AR by Monday afternoon, with the heaviest rainfall expected Monday night mainly for western/northwest AR. Expect a very sharp cutoff along the western edge of the precipitation, with areas along and west of Highway 75 in OK likely receiving little, if any, rainfall. The main rainfall axis will continue to be refined over the next few days. A cold front will sweep through the region by Tuesday night, bringing cooler and drier air for a few days. Stuck with the NBM for temperatures late next week, although the latest ECMWF is showing significantly stronger upper ridging than the GFS. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Heat Advisory until 7 PM CDT this evening for OKZ049-053>057- 059>062-064>067-070>076. AR...Heat Advisory until 7 PM CDT this evening for ARZ019-020-029. && $$ AVIATION.....08