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

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FXUS64 KMRX 160719
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
319 AM EDT Mon Jul 16 2018

.SHORT TERM...(Today and Tonight)...
Remnant elevated instability combined with the passage of a weak
vort impulse continues to promote convection across portions of the
region this morning, mainly concentrated along the east TN high
terrain, with a few lighter showers over SW VA.  Am expecting said
convection to continue for a few more hours, all the while weakening
as the aforementioned upper vort moves east.  Weak steering flow has
allowed for ample rainfall accumulations both last night and this
morning, with some sites reporting upward of 2-3 inches.  Lastly,
patchy fog could show itself around daybreak, especially for these
already saturated locales, however shouldn`t last long.

Moving on, an H5 shortwave will push east today across the OH/TN
valleys, further suppressing any deep subsidence from the earlier
ridge.  This combined with modest instability this afternoon will
favor convection across much, if not all of the fcst area.  With
that, guidance trends look to favor said convection over the mtns
and Plateau regions initially before slowly spilling into the
valley.  In addition, a broken line of convection associated with
the approaching wave and vort is progged across KY, likely to move
east/southeast into TN and SW VA later tonight.  This one/two punch
combined with the rainfall from last night and this morning could
pose at least an isolated flash flooding threat, specifically for
the high terrain of east TN and southwest VA/NC which have seen the
most rainfall.  Given moist profiles and weak shear, not expecting
much in the way of severe storms, however cannot rule out some gusty
winds associated with the more deeply forced convection moving in
out of KY this evening.  As for the fcst, pops remain rather low
this morning, topping out in the likely range this afternoon before
tapering from the southwest overnight.  Highs today are fcst
slightly cooler given expected sky cover, generally in the mid/upper
80s in the valley, upper 70s to lower 80s across the higher
terrain.

.LONG TERM...(Tuesday through Sunday)...
The eastern U.S. trough and associated front will produce
numerous showers and thunderstorms on Tuesday clearing the area
later on Tuesday night. These storms may produce locally heavy
rain as PW values approach 2 inches. Drier air will filter in
behind the front and bring lower humidities and drier conditions
on Wednesday and Thursday. However, rain chances will increase
starting mainly on Thursday night through Saturday night. This
will be in response to a deepening low/trough over the Great Lakes
extending into the southeast U.S. At this time Sunday looks drier
on the west side of the trough axis. Temperatures by the weekend,
should the trough materialize, will be about 3-5 degrees cooler
through the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             88  73  90  70 /  60  50  50  30
Knoxville McGhee Tyson Airport, TN  87  72  87  68 /  60  50  60  30
Oak Ridge, TN                       87  72  88  68 /  60  60  60  20
Tri Cities Airport, TN              84  70  85  64 /  70  60  60  30

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...None.
VA...None.
&&

$$

CDG/AC


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