259
FXUS64 KMRX 150515 AAC
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
115 AM EDT Sun Sep 15 2024

...New AVIATION...

.UPDATE...
Issued at 1017 PM EDT Sat Sep 14 2024

Forecast remains in pretty good shape this evening. Main
adjustment was to hourly temps as much of the central and
southern valley were a few degrees warmer than the forecast.
Adjustments resulted in slight increase in overnight lows of 1-3
degrees, nothing too significant. A mix of light wind and clouds
in some areas will prohibit any impactful fog development. A low
chance of very brief and light precip in the southern
plateau/valley continues over the next few hours, otherwise, a
very quiet night.

&&

.SHORT TERM...
(This evening through Sunday)
Issued at 223 PM EDT Sat Sep 14 2024

Key Messages:

1. Showers possible across southeast TN and southwest NC, but
overall largely expect dry conditions for most of the area today.

2. Another warm day, with temperatures 2-4 degrees above normal.

Discussion:

Currently band of precipitation from Alabama app into Middle TN is
continuing to produce showers. In eastern Tennessee we`re seeing
more isolated showers present across the central and southern
Tennessee Valley as the remnants of Francine help bring in
enhanced moisture. With the weaker downsloping flow across the area
today and warm temperatures in the central and southern valley more
widespread storms are able to develop in the afternoon sun. As of
this writing there are no lightning strikes present anywhere in the
region, but cannot rule out a rogue thunderstorm during the peak
heating of the day. As we move into the overnight hours expect the
intensity and coverage of the storms to decrease as the moisture
associated with the tropical remnants pulls back to the east.

&&

.LONG TERM...
(Sunday night through next Saturday)
Issued at 223 PM EDT Sat Sep 14 2024

Key Messages:

1. Gusty winds across higher southern Appalachian Mountains Sunday

2. Most areas are expected to see little rainfall for the extended
period, but there is low confidence in the details.

Discussion:

Forecast is difficult to pin down once we get into next week as the
remnants of Francine look to eventually dissipate into the mean
flow, and the possibility of another tropical system off the coast
of the Carolina`s eventually comes into play.

Higher confidence that we`ll see a return of gusty winds Sunday into
Monday with gusts over 30mph looking possible in the higher terrain
with the uptick in the easterly flow. At this time it looks like we
should remain below advisory criteria, but any campers in the
mountains should be prepared for some gusty winds at times.

Moving into next week we can expect to see temperatures hovering
near the seasonal normals as a broad ridge remains over the eastern
United States and a weak rex block continues with the lower
pressures situated underneath the ridge. With this being an atypical
set up it leads to a decrease in deterministic and probabilistic
model guidance as there just isn`t as much data to look back upon.
However a general trend of fairly dry weather is emerging. With the
the best chances to see rainfall likely across northeast Tennesee
and southwest Virginia during middle of the week as the Atlantic
system of the coast of the Carolina`s looks to drive westward to the
towards the southern Appalachians. Still much up in the air with
regards to the intensity and track of this system,  but at this time
locations north of Interstate 40 look to have the best chance to see
rainfall from Generally Tuesday into Wednesday. Beyond that the
remnants of the low could truck towards the Great Lakes region
before stalling out and begin to dissipate. If this then gets pushed
further south we could see a second round of precipitation as we
head towards the weekend. But again, lots of uncertainty with these
fairly weak and atypical weather patterns.

&&

.AVIATION...
(06Z TAFS)
Issued at 106 AM EDT Sun Sep 15 2024

VFR conditions should prevail through the period. Don`t expect
there to be any SHRA affecting KCHA today so will go with a dry
forecast at all sites. Gusts to around 20kt should occur again at
KTYS thanks to down valley pressure gradients, but I am less
confident elsewhere as support in guidance is mixed.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             87  65  85  63 /  10  10  10  10
Knoxville McGhee Tyson Airport, TN  88  63  84  60 /  10   0  20  20
Oak Ridge, TN                       87  63  84  58 /  10   0  20  20
Tri Cities Airport, TN              82  59  80  57 /   0   0  20  30

&&

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

$$

SHORT TERM...
AVIATION...CD