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

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FXUS64 KMRX 230727
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
327 AM EDT Fri Jun 23 2017

.SHORT TERM (Today and Tonight)...
Latest surface analysis and regional radar indicates remnant of
Cindy is currently located over south central Arkansas. This low
is forecast to move N through this morning before turning NE and
accelerating as it moves across KY this afternoon and into SE
Pennsylvania by Saturday morning.

Water vapor imagery indicates a band of tropical moisture feeding
N across Western Alabama into Middle and East TN this morning. Not
accounting for this band which is producing 1 hour rainfall
totals of near an inch, the 12 hour rainfall totals across the
area have been rather modest with less than a half inch total over
much of the area. Exception to this is areas of Marion and
Hamilton counties in SE TN which have seen radar estimates of up
to 1.5 inches during this time.

Water vapor shows a small and well-defined dry slot siting between
Cindy remnants and the band currently affecting Middle/East TN.
This dry slot is expected to shift NE ahead of Cindy today helping
to minimize potential for large scale heavy rains through this
afternoon. This reduces flood threat area wide, with concern of
localized flash flooding still possible in the training band this
morning over the Southern Cumberland Plateau including Marion and
Hamilton counties.

Models are in good agreement with a line a strong to possibly
severe thunderstorms pushing east across the area this evening as
Cindy accelerates northeast across KY. Forecasted SBCAPE values
to near 1000 J/Kg, SFC-3KM shear of 40 KT, and the expected
impressive low-level SRH of 200-300 m2/s2 during this time
increase the risk for severe thunderstorms with the potential for
a few tornadoes as this final band of convection pushes through
the area. Additionally, 50-60 kt 850 MB winds SE of Cindy could
mix down in any convective cells resulting in localized severe
wind damage as well.

.LONG TERM (Saturday through Thursday)...
The remnants of Tropical Storm Cindy will be NE of the area by
Saturday morning...with flow shifting to out of the NW. Moisture
will remain...especially in the low levels...for a scattered light
showers and isolated thunder to continue through the
day...tapering off from the west to east beginning mid day. By
Saturday evening...all activity should be east of the
Appalachians...with ample dry and cooler air continuing to filter
in. Temperatures Saturday will be a couple of degrees below normal
due to the cloud cover expected to remain through the warming of
the day.

Sunday through Thursday...an upper level trough swings through
the region. With NW flow remaining...mostly clear skies and dry
weather is expected...with a gradual warming trend to the
temperatures each day. Models try to bring in a few light
scattered showers Monday evening in to Tuesday...mainly to the
higher elevations...but due to low confidence in model
consistency...have left mention of showers out of forecast for
now. On Thursday...a boundary around a low pressure system moving
across the northern Ohio Valley...is expected to swing through the
region. Scattered showers and thunderstorms can be expected
through the afternoon if the boundary holds together by the end of
the extended.


&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             85  73  83  63 /  70  80  50  10
Knoxville McGhee Tyson Airport, TN  85  70  81  61 /  50  80  40  10
Oak Ridge, TN                       84  71  82  60 /  60  80  40  10
Tri Cities Airport, TN              83  69  80  59 /  50  90  30  10

&&

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

$$

EJH/JW


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