Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
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285 FXUS64 KMRX 131936 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 336 PM EDT Tue Aug 13 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (This evening through Wednesday) Issued at 257 PM EDT Tue Aug 13 2024 Key Messages: 1. Slightly below normal temperatures tonight and near normal temperatures tomorrow. 2. Mostly dry through Wednesday. Discussion: Overall, same story different day. We remain in a northwest flow pattern with troughing to our northeast and an upper level ridge axis to west-northwest. Outside of a slight chance for a shower or storm across the northeast TN mountains, all areas will be dry through tonight. Also, slightly below normal low temps will be in place again tonight due to the dry air that remain in place. Tomorrow, mostly dry weather continues as high pressure shifts further east and the ridge becomes centered over the eastern U.S. Slight chance for an afternoon shower or storm across southwest NC and the east TN mountains. && .LONG TERM... (Wednesday night through next Tuesday) Issued at 257 PM EDT Tue Aug 13 2024 Key Messages: 1. Mostly dry weather Thursday. Warmer Friday with increasing chances of showers and storms heading into the weekend. 2. Cold front forecast to cross the area sometime on Saturday with possibly drier conditions to finish off the weekend and start the new work week. Discussion: Troughing setting up across the northern tier of the U.S. by Thursday will feature three upper lows; along west coast, over the Upper Plains and over the Canadian Maritimes. The one furthest east will steer Ernesto over open waters in the coming days, while the closed low yet to form over the Upper Plains/Upper Mississippi Valley, will bring us increased chances for showers and thunderstorms by the weekend. Before that happens, Thursday should be mostly dry with any activity confined to the higher terrain. Friday appears will be the warmest day when SWly flow is at its height ahead of the approaching front. Precipitation will increase from the west and northwest, the best chances headed into Saturday. As noted in this morning`s discussion, an eye will be kept on the time period of frontal passage, as CAPE up to 1500 J/kg is possible as well as an increase in effective shear. SPC currently isn`t confident on a 15% anywhere this far out due to convergence along the front may not be as strong and antecedent convection hampering severe potential. To finish the period, temperatures will fall back into the 80s in the valley and chances for precipitation may linger. Longwave troughing will move to the northeast, allowing ridging to build out west. Our area will remain under northwesterly flow with weak disturbances supporting development, but the further out in time, the greater the uncertainty of coverage and timing. && .AVIATION... (18Z TAFS) Issued at 121 PM EDT Tue Aug 13 2024 VFR conditions through the period at all sites with light northerly winds at CHA and TYS with VRB at TRI. A few data sources showing fog at TRI tonight but low confidence so will not include in this TAF set. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 67 90 70 91 / 0 0 0 10 Knoxville McGhee Tyson Airport, TN 65 89 66 89 / 0 0 0 10 Oak Ridge, TN 65 88 66 89 / 0 0 0 10 Tri Cities Airport, TN 61 86 62 86 / 0 10 0 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM... LONG TERM....KS AVIATION...