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

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000 FXUS64 KMRX 300929 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 429 AM EST Wed Nov 30 2016 .SHORT TERM (Today)...
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Strong low level southerly winds coupled with a very moist boundary layer having dewpoints into the middle 60s and MLCAPE values of 250-500 are supporting severe storm activity across the area this morning. Expect this to continue at least into the late morning until the 850 mb jet finally lifts NE of the area. Coupled with the ongoing severe threat, excessive rainfall remains a serious issue with radar estimated totals already reaching to near 3 inches in spots and a rather large swath of 1-2 inches extending NE along the I-75 corridor. Three hour flash flood guidance ranges from 2-3 inches area wide. With next round of rain this morning expected to produce an additional 1-2 inches in spots, potential for flash flooding will need to monitored closely. Categorical pops through the early afternoon before the front finally makes a push east and we see decreasing pops west to east by this evening. .LONG TERM (Tonight through Tuesday)... Big question is the weekend forecast which has fairly good model agreement through Sunday morning on the evolution of an overrunning event. With overnight lows fcst to be in the middle 30s over all but our SW VA counties... where lows are going to be hovering near freezing coupled with timing of pcpn, would not rule out period of mixed pcpn very early Sunday morning over some spots in SW VA. Will need to monitor this closely over the next day or so in order to better refine pcpn type/duration in that area Sunday morning. By late Sunday guidance starts to diverge significantly with GFS developing a gulf low by Monday night while the ECMWF forces everything east leaving the area under influence of high pressure and remaining rather dry. Even the GFS ensemble 500 mb heights are strongly divergent with two bulls-eye lows showing up in the members. The first is over western texas and other over western Tennessee. Given the divergence of the solutions...went with a pure blended solution of chance pops across the area for now.
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&& .PRELIMINARY POINT TEMPS/POPS...
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Chattanooga Airport, TN 68 40 57 35 / 100 10 10 0 Knoxville McGhee Tyson Airport, TN 67 41 53 34 / 100 20 10 0 Oak Ridge, TN 66 41 52 33 / 100 10 10 0 Tri Cities Airport, TN 67 39 51 30 / 100 40 10 0
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&& .MRX WATCHES/WARNINGS/ADVISORIES... NC...Wind Advisory until 3 PM EST this afternoon for Cherokee-Clay. TN...Wind Advisory until 3 PM EST this afternoon for East Polk- Johnson-NW Blount-North Sevier-Northwest Carter-Northwest Cocke-Northwest Greene-Northwest Monroe-Southeast Carter- Southeast Greene-Southeast Monroe-Unicoi-Washington TN. High Wind Warning until 3 PM EST this afternoon for Blount Smoky Mountains-Cocke Smoky Mountains-Sevier Smoky Mountains. VA...Wind Advisory until 3 PM EST this afternoon for Wise. && $$ EJH

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