727
FXUS64 KMRX 110613 AAC
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
213 AM EDT Sat May 11 2024

...New AVIATION...

.UPDATE...
Issued at 935 PM EDT Fri May 10 2024

A quiet Friday evening with no big forecast updates. Made slight
adjustments to hourly temps and dewpoints to match up with latest
obs but otherwise no changes.

&&

.SHORT TERM...
(This evening through Saturday)
Issued at 303 PM EDT Fri May 10 2024

Key Message:

Scattered showers and some thunderstorms expected this afternoon
should dissipate after sunset.

Discussion:

Currently there are showers and a few thunderstorms present across
northeast Tennessee and southwest Virginia as a shortwave is likely
directly above us moving east/southeast. This also in conjunction
with an upper level jet moving through the Tennessee Valley that is
providing additional divergence aloft. Based on this synoptic set up
and additional CAM guidance it still looks like the greatest
coverage of storms and best chances to see lightning will be along
and north of Interstate 40 this afternoon/evening.

Storms that have already developed are moving southeast at around 20
mph, which will hopefully limit the flooding potential of them...
But they could produce enough rainfall in to slightly re-aggravate
flood prone areas this afternoon. But more widespread flooding is
not anticipated at this time.

As we move into the evening and overnight hours the shortwave and
diurnal heating will both be over with and we`ll return to quiet
weather. In addition the winds should slack off and we`ll likely see
some patchy fog develop, especially in the river valleys and areas
that still have some standing water from the recent rainfall. With
the clearer skies and light northwest winds we`ll see temperatures
drop to near 50 south of I-40 and into the 40`s for many places
north of the Interstate.

Tomorrow should be a similar story as today with afternoon showers
and some thunderstorms expected to develop again. However, coverage
should be less tomorrow with worse synoptic forcing in the region.

&&

.LONG TERM...
(Saturday night through next Friday)
Issued at 303 PM EDT Fri May 10 2024

Key Messages:

1. Dry weather and near normal or slightly below normal temps to
finish out the weekend on Sunday.

2. An active pattern sets up starting Monday afternoon, with rain
and thunderstorm chances through at least Wednesday.

Discussion:

On Sunday, a ridge is moving into the region from the west. Sunday
will be dry and sunny with highs around or slightly below normal as
northerly flow continues in the lower levels. By Monday afternoon,
high pressure is still over the Southeast but the ridge is drifting
eastward as a trough is moving into the Mississippi Valley. POPs
start to increase Monday afternoon but Tuesday has higher chances
for showers and storms as that trough and a vertically stacked
surface low move into the Ohio and Tennessee Valleys. By Wednesday
afternoon or night a ridge starts to build into the region but
another system may move in by Friday.

Overall, a wet pattern will be in place next week with forecast rain
totals of 1 to 2 inches. Instability does not look too impressive
with dew points mainly in the lower 60s. A few strong to severe
storms cannot be ruled out particularly Tuesday when shear looks
most favorable but confidence is low this far out. With a wet
pattern in place next week, highs will be near or below normal with
increased cloud cover.

&&

.AVIATION...
(06Z TAFS)
Issued at 208 AM EDT Sat May 11 2024

VFR conditions expected for much of the 06z TAF period. The
exception may be KTRI where some fog is expected to develop over
the next few hours. Guidance is mixed on how widespread this
becomes, so will leave VSBY restriction capped at 5SM for now.
Also have a weak cold front coming in today. Much like yesterday
some scattered showers are expected to develop, with coverage
being better the further north you go. Think VCSH from 17z - 00z
at KTRI will be sufficient, and will leave other terminals dry.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             77  53  80  57 /   0   0   0   0
Knoxville McGhee Tyson Airport, TN  72  50  75  52 /  20  10   0   0
Oak Ridge, TN                       74  48  77  53 /  20   0   0   0
Tri Cities Airport, TN              67  46  72  47 /  30  10   0   0

&&

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

$$

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