-- Discussion containing changed information from previous version are highlighted. --
000
FXUS64 KMRX 270203
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
1003 PM EDT Fri Apr 26 2024

...New UPDATE...

.UPDATE...
Issued at 1001 PM EDT Fri Apr 26 2024

Winds have increased a bit more in some of the usual spots, so
will go ahead and issue the wind advisory for the mountains and
foothills of the E TN mountains through 6 AM.

&&

.UPDATE...
Issued at 913 PM EDT Fri Apr 26 2024

Radar shows the last of the precipitation is dissipating, and will
remove the remaining slight chance PoPs with this update. With the
southeast flow, there continue to be some wind gusts to around 40
mph in some of the usual mountain wave enhanced wind areas, and
this will continue overnight before they diminish, but still looks
marginal for a wind advisory and given the limited area impacted
and marginal wind speeds expected none will be issued for now.
Overall, the forecast looks reasonable so mainly just some minor
adjustments to temps and dew points with this update.

&&

.SHORT TERM...
(This evening through Saturday)
Issued at 250 PM EDT Fri Apr 26 2024

Key Messages:

1. Light rain will continue its trek from approximately Knoxville
northeastward into Southwest VA before exiting tonight.

2. Breezy conditions, especially over the higher terrain and
adjacent foothills into tomorrow. No Wind products are in effect.

Discussion:

A rather overperformed isentropic lift will continue it`s exit
to the northeast tonight, bringing possibly up to a half inch of
rain to far northeast Tennessee and southwest VA. Over a half inch
had fallen from the line just southwest of Knoxville this morning
through the early afternoon. The afternoon highs today may
struggle to reach what was forecast due to the slow moving line of
precip and cloudy conditions. As of 3 PM EDT, Chattanooga is
about the only location in our forecast area in the 70`s.

Skies look to remain mostly cloudy overnight with clearer
conditions in the southern valley and plateau. This may inhibit
fog development overnight, but will monitor it. The only "calm"
areas tonight will be the central and northern valley up into
Scott County, VA where most of the rain has fallen or is headed.
On the subject of winds, expect sub-advisory gusts to persist
over the higher terrain and some adjacent foothills. Gusts should
mostly stay under 35 mph. Gusts up to 25 mph are possible in
valley locations tomorrow afternoon.

Overall, Saturday looks to be a better day with dry weather and
clouds slowly thinning. A warming trend also begins into the
weekend under the influence of ridging aloft and surface high
pressure over the western Atlantic.

&&

.LONG TERM...
(Saturday night through next Friday)
Issued at 250 PM EDT Fri Apr 26 2024

Key Messages:

1. Continued above normal temperatures, with highs 8-10 degrees
above normal expected.

2. Dry into early next week, but then daily chances for at least
scattered showers and thunderstorms starting Tuesday.

Discussion:

Upper level ridging will remain anchored over the southeast CONUS
from Saturday night into early next week, keeping our forecast area
precip free and on the warm side through that time. Expect highs on
Sunday and Monday to be in the neighborhood of 8-10 degrees above
normal.

Meanwhile, between Saturday night and late Sunday afternoon and
evening, a closed upper low will have ejected northeast from the
Colorado Rockies into the northern plains, leaving a cold front
situated from the upper midwest down through the Ozarks and into the
southern plains by Monday morning. As mentioned, we`ll be rain free
during this time. But this set up will present us with rain chances
on Tuesday as the front shifts further east in response to the
aforementioned upper low moving through the Great Lakes and into
Canada and a southern stream shortwave moving east through the deep
south. The front itself likely gets held up to our NW, so this
doesn`t appear to be a true FROPA next week. But the southern stream
shortwave should result in fairly widespread coverage of showers and
thunderstorms on Tuesday. Severe potential with this system still
looks to be low, so general thunder is all that is expected at this
time.

For Wednesday onward next week the upper pattern looks less
amplified across the CONUS, with broad ridging over the southeast
(and weak troughing over the Rockies) still. However areas from the
Arklatex region, northeast into the Tennessee valley will lie
beneath southwesterly upper flow and solid return flow off the
GOMEX. Embedded in those southwesterlies will be weak impulses that
will almost certainly result in some scattered afternoon convection
each day, with rain chances favoring areas of higher terrain and
also northern areas closer to the aforementioned stalled front.

&&

.AVIATION...
(00Z TAFS)
Issued at 633 PM EDT Fri Apr 26 2024

VFR conditions are expected for the period at CHA and TYS,
although cigs around/shortly after sunrise at CHA may dip to
near, or even briefly down to, MVFR levels before the cloud deck
lifts/scatters out. At TRI, difficult vsby forecast as rain is
ending and moist low levels look favorable for fog, but stubborn
clouds may hang in for much of the night. Will forecast a period
with MVFR vsby at TRI, but if cloud do scatter out early enough
there will be a high chance for much lower vsby.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             63  79  62  82 /  10  10   0   0
Knoxville McGhee Tyson Airport, TN  57  79  58  82 /   0  10   0   0
Oak Ridge, TN                       56  79  59  82 /   0  10   0   0
Tri Cities Airport, TN              54  76  55  81 /  20  10   0   0

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
NC...NONE.
TN...Wind Advisory until 6 AM EDT Saturday for Blount Smoky Mountains-
     Cocke Smoky Mountains-Sevier Smoky Mountains-Southeast
     Carter-Southeast Greene-Southeast Monroe-Unicoi.

VA...NONE.
-- End Changed Discussion --
&&

$$

SHORT TERM...
LONG TERM....CD
AVIATION...