Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS64 KMRX 220657 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 257 AM EDT Fri Sep 22 2017 .SHORT TERM (Today through tonight)...At the beginning of this period, we are under a rare northeast flow aloft, between high pressure to our west and northwest over the Miss Valley and a trough to our east associated with tropical system Jose. Short-range models show some deep convection developing today over the high terrain near the TN/NC state line during the afternoon heating, but with the flow from the northeast, much of this convection/precip will stay over this high terrain, riding down the ridgeline. The NE flow will proceed to push this convection across the Hiwassee and Ocoee Valleys in our extreme southeastern counties this afternoon. With the convection being driven by the diurnal heating, it should fade quickly this evening. Drainage winds again tonight should favor a repeat of localized valley/lake fog late tonight. Will stick close to guidance temps. .Long Term (Saturday through Thursday)...Once again, a quiet and uneventful long-term period in store but change is on the horizon. High pressure centered over the Great Lakes region will continue to dominate our weather through the extended, allowing for above normal temperatures and little to no rain chances. Have slight chance POPs to start the period Saturday afternoon across portions of southern plateau, SWNC, and our eastern mountains. Then no POPs through the rest of the week until Thursday. Highs Saturday through Wednesday will generally be in the mid to upper 80s, which is around 5 to 8 degrees above normal. Lows will be in the low to mid 60s, which is around 5 degrees above normal. High pressure breaks down on Thursday in response to an upper level trough moving across the Great Lakes. This trough has an associated frontal boundary that will make it`s way through our area but beyond this long-term forecast. The front is across the Ohio River Valley on Thursday. By Thursday afternoon have slight chance POPs in for all areas as front draws closer. Highs on Thursday will be a few degrees cooler as flow becomes more zonal. Highs will be in the upper 70s to lower 80s. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 88 66 87 65 / 10 10 10 0 Knoxville McGhee Tyson Airport, TN 87 65 87 64 / 10 10 0 0 Oak Ridge, TN 88 65 87 64 / 10 10 10 0 Tri Cities Airport, TN 85 60 86 58 / 10 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$ GM/SR

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.