726
FXUS64 KMRX 271734 AAC
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
134 PM EDT Sat Apr 27 2024

...New AVIATION...

.UPDATE...
Issued at 1045 AM EDT Sat Apr 27 2024

No significant changes for the morning update. Winds remain below
advisory criteria in our typical mountain wave locations so the
decision by the night shift to let the wind advisory go at 6 AM is
working out nicely. Should continue to see gusts of 30-40 mph
through early this afternoon but expect them to continue to remain
below advisory criteria. Otherwise, made some minor tweaks to
afternoon temps. Blended in some HRRR guidance which has some
cooler temps where morning clouds were thicker and slightly higher
values where clouds were non existent. But these weren`t
significant changes, maybe a degree or so.

&&

.SHORT TERM...
(Today and tonight)
Issued at 318 AM EDT Sat Apr 27 2024

Key Messages:

1. Winds diminish in the mountains and foothills this morning, the
Wind Advisory will continue unchanged.

2. Warm temperatures today despite some high clouds.

Discussion:

Current wind gust speeds are currently near their peak, with both
Cove Mountain and Camp Creek reporting 52 mph. This is likely due to
a nocturnal jet, so as we near sunrise, wind speeds should diminish.
This trend is also shown by the latest CAMS. The Wind Advisory
will remain unchanged, continuing until 6 AM.

A large high pressure ridge through the lower and mid levels will
continue to be located east of the area today and tonight, across
eastern GA and the Carolinas. High clouds associated with a weak
shortwave trough on the west side of the ridge will be mainly broken
through the morning, with some reduction in coverage this
afternoon as the shortwave trough exits. With the southerly low
level flow and decreasing cloud cover, highs today will be warm,
in the 75 to 80 range in most Valley locations. Tonight will be
mostly clear, and not as windy in the mountains as the pressure
gradient slackens. Lows will be mainly in the mid to upper 50s.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 318 AM EDT Sat Apr 27 2024

Key Messages:

1. Continued above normal temperatures, highs up to 10 degrees above
normal expected through the period.

2. Dry through Monday, but then daily chances for at least scattered
showers and thunderstorms Tuesday through Friday. Rainfall amounts
not that high but could occur each day from Tuesday morning through
Friday.

Discussion:

Upper level ridging stays in place over the southeastern states from
Sunday into early next week, keeping forecast area rain free and
warm through Monday. Highs Sunday and Monday significantly above
normal.

To the northwest Sunday, a closed upper low will move from eastern
Colorado into the northern plains with a cold front extending
southward through the Ozarks and just west of the Mississippi River
in Arkansas by early Monday morning. Monday morning the upper low
will be in the western Great Lakes and Canadian border with the
trailing cold front approaching the Mississippi River. As ridging
stays strong temperatures will warm into the lower to mid 80s Monday
in the Tennessee Valley. Tuesday the front shifts further east as an
upper low goes east across the Great Lakes and southern Canada. A
southern stream shortwave will be moving east through the deep
south. The front itself is likely to get held up to the NW and there
may not be a FROPA. But the southern stream shortwave should result
in good coverage of showers and thunderstorms Tuesday. The severe
potential with this system still looks low and expect only general
thunder across the eastern Tennessee Valley at this time.

Wednesday through Friday next week the upper pattern looks less
amplified across the CONUS, more westerly low level flow and broad
ridging over the southeastern US. Areas from the Arklatex region,
east into the Tennessee valley will lie below a southwesterly upper
flow and returning moisture off the Gulf. As flow gradually becomes
more southwest and weak shortwaves move through they will result in
some scattered afternoon showers and storms each day, with rain
chances better in the higher terrain and also across northern areas
closer to a stalled front. Rainfall amounts overall will be light
through the period so no flooding expected.

&&

.AVIATION...
(18Z TAFS)
Issued at 125 PM EDT Sat Apr 27 2024

VFR flight categories are expected through the period. Gusty winds
of around 20kt will continue at KTYS and KCHA through late this
afternoon, and again tomorrow. Doubt KTRI sees much in the way of
any gusts. The only caveat to the forecast that I can see is that
some guidance brings in another round of morning MVFR CIGS to
KCHA again tomorrow. The overall pattern would favor such a thing,
but since it`s not well agreed on in the models, I`m a bit
skeptical of including it with the 18z TAF package.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             79  61  83  61 /  10   0   0   0
Knoxville McGhee Tyson Airport, TN  79  59  83  59 /   0   0   0   0
Oak Ridge, TN                       78  59  83  60 /  10   0   0   0
Tri Cities Airport, TN              76  55  81  55 /  10   0   0   0

&&

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

$$

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