-- Discussion containing changed information from previous version are highlighted. --
576
FXUS64 KMRX 021108 AAA
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
708 AM EDT Thu May 2 2024

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 252 AM EDT Thu May 2 2024

Key Messages:

1. Above normal temperatures and dry conditions continue.

2. Chance of rain enters southern sections late tonight.

Discussion:

A large high pressure ridge through the column will be centered to
our east over the Carolinas. This will provide a deep S-SW flow
across the TN Valley. A dry, cloud-free column will allow
temperatures to reach full sun highs in the mid to upper 80s in
most spots. This will be a few degrees short of record highs.

A shortwave trough at the 700-500 mb level will cross the MS
Valley in the evening and continue E-NE overnight. Lift ahead of
this trough will begin to spread some showers into the southern
Plateau in the 09-12Z time frame.

&&

.LONG TERM...
(Friday through Wednesday)
Issued at 252 AM EDT Thu May 2 2024

Key Messages:

1. Near normal to above normal temperatures through the long term.

2. Unsettled pattern with chances for showers and thunderstorms each
day of the long term. More diurnal pattern of convection last three
days of the period Tuesday through Thursday next week.

Discussion:

Friday the upper ridge that has been over us the last day or so
begins to push east and a broad longwave trough approaches from the
west. Lower pressure over southern Canada will be moving north and a
weak cold front extending southward through the lower Ohio Valley
and into Arkansas that is accompanying the trough will slowly move
east southeast. Showers and some thunderstorms are expected to
develop out ahead of it during the day Friday with initial
shortwave. CAPE values reach 1000 to 1500 J/KG during the day so
with some heating into the lower 80s thunderstorms should form. Not
expecting any severe storms but gusty winds possible and small hail.
The front only very slowly moves east and second shortwave comes
through Saturday into Saturday night with more showers and
thunderstorms developing, Highs Saturday will be cooler with more
clouds only mid 70s to near 80. Rain chances will be high both days.
On Sunday either a wave forms to the west and moves along the front
or a secondary front develops so have another good chance of showers
and storms Sunday.

Monday, the upper level ridging rebuilds back into the forecast
area. The frontal system Sunday lifts back northward as a warm front
but at the same time another in the parade of shortwaves will follow
the western part of the ridge and cause storms to redevelop during
the day Monday. For Tuesday through Thursday similar conditions with
daytime heating and higher instability being favorable for more
afternoon and evening showers and thunderstorms. The activity looks
more diurnal with 20 percent chance in the south and 30 percent
central and northern areas. A longwave trough will be over the north
central states and the northeast with a front farther to the north
of the forecast area near the base of this trough. There is some
indication these storms could be stronger with higher CAPE values.
It will depend on where and when storms develop and cloud cover from
each days convection.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 706 AM EDT Thu May 2 2024

TAFs will be VFR but there is some uncertainty about CHA in the
next hour, as the ob reports MIFG and SCT005. Expect that this
will not result in lower vis/cigs at the runway, but it cannot be
ruled out. Today will be mostly sunny with light wind, although
CHA may have S wind approaching 10 kt. Showers will begin to move
into the area from the west late in the period, and VCSH will be
mentioned at CHA.
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             88  65  81  65 /   0  30  60  70
Knoxville McGhee Tyson Airport, TN  87  61  81  64 /   0  10  70  70
Oak Ridge, TN                       87  62  81  63 /   0  10  70  60
Tri Cities Airport, TN              85  57  82  62 /   0   0  40  60

&&

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

$$

SHORT TERM...DGS
LONG TERM....TD
AVIATION...DGS