321 
FXUS64 KMRX 102336 AAA
AFDMRX

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Morristown TN
736 PM EDT Fri Jul 10 2020

.UPDATE...
FOR 00Z AVIATION.

&&

.SHORT TERM... (Today through tomorrow)...
Currently a shortwave moving across the midwest and bringing along 
with it a surface low and cold front from the Great Lakes region 
down through the southeastern United States. Ahead of this front 
today winds are out of the south to southwest helping to bring in 
warm and moist air. This will allow air temperatures to climb well 
above average, and combined with the higher dew points means that we 
should see apparent temperatures and climbing into the triple in the 
southern portions of the Eastern Tennessee Valley. 

These warm temperatures and increased dew points are also leading to 
increased coverage of showers and thunderstorms this afternoon, 
especially in NE Tennessee and SW Virginia closer to the shortwave 
along a pre-frontal trough. Expect coverage to begin to increase a 
bit through the late afternoon, especially if storms are able to get 
additional lift along the Southern Appalachian Mountains. MLCAPE 
values of up to approximately 1500 J/kg will allow for decent sized 
storms that are able to form with this heat. However little to no 
shear is present across much of the area meaning storms won't be 
able to organize particularly well. Best chance for storm 
organization is in SW Virginia closer to the trough. Also up in SW 
Virginia is the location of the highest DCAPE values with increased 
mid-level dry air. Believe that most places that do experience 
storms should just see typical summer thunderstorms, but it's 
possible a few storms could become strong with strong straight-line 
winds being the main concern. Storms are currently moving eastward 
at a decent clip, so unless a particular location sees multiple 
rounds of rain, hopefully the flooding threat is limited this 
afternoon/evening.

Front should push through the area overnight, and while it will only 
cool temperatures off a few degrees it will help clear out some of 
the moisture in the air leading to lower dew points heading into 
tomorrow. Temperatures will be able to rebound back up to similar to 
what we experience today, but the lower dew points will lead to much 
lower apparent temperatures and a more pleasant afternoon, and much 
lower storm coverage.

ABM

.LONG TERM...(Saturday night through Friday)...
We start the period off dry as we are in a drier air mass behind 
our departed front. However, chances for showers and storms 
increase through the day on Sunday as a weak shortwave and another
frontal boundary move across the area from out of the northwest. 
The SPC currently has our area under marginal risk as a broad 50 
to 60kt 300mb jet will provide weak upper level support and result
in 0-6km shear of around 30kts. For this reason, a few isolated 
storms may become strong to severe during the afternoon hours. 
Showers and storms decrease Sunday evening as the short wave exits
and high pressure begins to build back in from the west. Models 
still unclear on how fast moisture moves out behind the front so 
kept slight chance POPs in place on Monday but wouldn't be 
surprised if most places stay dry.

Tuesday and Wednesday are dry as a ridge of high pressure moves in 
from the west, along with drier air. However, will have some slight 
chance POPs in across the high terrain on Wednesday afternoon but 
most areas dry. High temps will be some of the warmest of the season 
with highs ranging from the low to upper 90s by Wednesday/Thursday. 
The ridge flattens Thursday and Friday and the flow becomes zonal. 
During this time, a few weak waves of energy move across the region 
and will result in slight chance/chance POPS with temps continuing 
to remain in the low to mid 90s.

SR


&&

.AVIATION...
00Z TAF DISCUSSION.

A few showers and thunderstorms were still moving across east 
Tennessee early this evening mainly northeast Tennessee ahead of a
cold front moving into eastern Tennessee. These showers will
affect northeast Tennessee over the next hour so have VCTS remark
at KTRI. Otherwise VFR with scattered clouds. Lower clouds and
decreased visibility late tonight and early saturday morning
at KTRI with the rainfall that fell this afternoon and possibly
this evening. MVFR to IFR conditions possible from about 09-13Z
Saturday then becoming VFR.

TD

&&

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

$$