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

Home | Current Version | Previous Version | Text Only | 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

000
FXUS64 KMRX 171929
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
329 PM EDT Fri Aug 17 2018

.SHORT TERM...(Tonight and Saturday)...
Upper trough over the Great Lakes and Ohio Valley will lift
northeast with a positive tilted trough/shear axis remaining
across the Ohio and Tennessee Valleys through Saturday.

Associated frontal boundary will remain north of the area with
the only low-level forcing mechanism being the terrain features.
Southwestery flow will continue to pull abundant moisture into the
region with PWs of 1.7-2.0 inches. MLCAPEs of 1500-2000 J/Kg today
and Saturday afternoon, so plenty of instability to produce
scattered storms. Again, best coverage over the elevated terrain.

Main concern will be isolated damaging winds (trees down)
and torrential rains with localized flash flooding possible.

Plenty of low-level moisture, recent rains at spots, and some
breaks in the cloud cover will allow for patchy fog development
late tonight/early Saturday morning.

.LONG TERM...(Saturday night through Thursday)...
Long term forecast still looks to be unsettled with a continual
chance for showers and thunderstorms. Upper trough over the area and
weak front moving through this weekend keeps area wet Saturday night
and the front may move just to the south early Sunday. This should
allow some drying before front moves back north as a warm front
later Sunday into Monday. Localized flooding possible into the
evening Saturday with high precipitable water values. Next trough to
move into the region Monday with increasing southwest flow and
another stronger cold front to approach Tuesday. Heavy rainfall may
be another problem Tuesday into Wednesday with the next front and
some strong storms ahead of the front. Behind the mid week front
later Wednesday decreasing rain chances as drier and cooler air mass
settles over the region. Have left slight chance pops near the
mountains. Temperatures near to slightly below normal during the day
and above normal at night through Wednesday. Thursday and Friday
mornings will be significantly cooler with clearing skies...in the
lower to mid 60s with mid to upper 50s mountains and valleys in the
northeast.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             72  83  71  86 /  70  70  50  50
Knoxville McGhee Tyson Airport, TN  70  83  70  85 /  60  70  70  50
Oak Ridge, TN                       71  82  71  85 /  70  70  60  50
Tri Cities Airport, TN              68  82  67  83 /  60  70  70  50

&&

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

$$




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