848
FXUS64 KMRX 291750 AAC
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
150 PM EDT Mon Apr 29 2024

...New AVIATION...

.UPDATE...
Issued at 933 AM EDT Mon Apr 29 2024

No major changes for the morning update. Current forecast is
tracking along nicely. Seems like another beautiful, but warm,
late April day. Did freshen up winds and dewpoints a tad. Blended
winds heavily towards the FV3 mainly because it seems like it`s
handling the calm winds in the northeast Tennessee valley very
well. Not a significant change to the forecast really, but it does
hold on to those lighter winds there longer into the day. Will
update the zones, but that`s about it for the update.

&&

.SHORT TERM...
(Today and tonight)
Issued at 307 AM EDT Mon Apr 29 2024

Key Messages:

1. A warm and dry pattern continues today.

2. Showers and a few thunderstorms will arrive late tonight.

Discussion:

The Wind Advisory has been canceled early as obs in the mountains
and foothills are showing peak gusts only in the 20s.

High pressure east Carolina coastline will continue to dominate the
region today, as it has for the past few days. Little change to the
sensible weather is expected today from what we have been seeing, as
a southerly flow will provide warm temperatures in the lower 80s for
most spots. There may be a bit more high cloud cover due to
upstream convection, but it will be a mostly sunny day overall.

Ongoing convection from Lake Michigan to the Ozarks is occurring
along a pre-frontal trough that will make its way east through the
day and tonight. This activity is expected to reach our Plateau
counties around 06Z tonight. It will be supported by good upper
divergence ahead of a shortwave trough and jet streak, and a
nocturnal LLJ around 40 kt, which should result in categorical
showers and scattered thunderstorms. However, the overnight timing
will mean very weak instability, with only a few hundred MUCAPE in
the NAM soundings at CHA, and thus no severe threat is expected.

&&

.LONG TERM...
(Tuesday through Sunday)
Issued at 307 AM EDT Mon Apr 29 2024

Key Messages:

1. Continued above normal temperatures through the week.

2. Active weather pattern to bring chances for showers and
thunderstorms Tuesday and Friday this week.

Discussion:

The period begins Tuesday morning with a cold front just to the
northwest moving into the Ohio Valley. Showers and some
thunderstorms will be moving into the western parts of the region in
the morning ahead of the cold front. Only general thunder is
expected. Currently, CAPE values are up to around 1000J/KG south and
eastern mountains which is high enough for a few strong storms in
the Tennessee Valley. Precipitation amounts should be moderate and
possibly over 1 inch in the Smokies and southern plateau which could
cause some minor flooding problems Tuesday. The front is forecast
not to move through but lift northward Tuesday. High temperatures
will be held down from Monday by the rain, only in the 70s which is
close to average for late April.

Beginning Wednesday and continuing into Thursday there will be a
break in the precipitation as surface high pressure builds in along
with upper level ridging extending northward from the Gulf to the
Tennessee Valley. Because of this high temperatures will again reach
the lower to mid 80`s Wednesday until the weekend. Possibly upper
80`s Thursday. These temperatures are about 10 degrees above normal
for the end of April.

On Friday and continuing through Sunday another cold front with a
low pressure area in the Great Lakes and the frontal system hanging
south just West of the Mississippi River is marching eastward.
Chances for precip exist much of the weekend as the system slows
Saturday and  stalls just south and east Sunday. A good chance of
showers and storms will accompany it as it moves southeast. Some of
these storms could be strong with CAPE values again around 700 J/KG
The increased cloud cover will hold down temperatures this weekend
just a few degrees to the upper 70s to lower 80s.

&&

.AVIATION...
(18Z TAFS)
Issued at 144 PM EDT Mon Apr 29 2024

VFR flight categories continue through late tonight at all
terminals. Should see SHRA begin to arrive from the west and
affect KCHA around 09z, and a couple of hours later at KTYS. They
likely hold off until 15z or shortly after at KTRI however. Not
expecting heavy SHRA, and TSRA should be limited in scope, so only
a gradual decline of ceilings to MVFR conditions is expected at
KCHA. Left it out of KTYS and KTRI due to later arrival time of
rain, and uncertainty in how low ceilings will drop.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             83  64  79  58 /   0  90  80   0
Knoxville McGhee Tyson Airport, TN  83  63  75  58 /   0  60  80  20
Oak Ridge, TN                       83  62  74  57 /   0  80  80  20
Tri Cities Airport, TN              83  58  74  56 /   0   0  90  30

&&

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

$$

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