Flash Flood Warning 18, NWS Morristown, TN

Area Forecast Discussion
National Weather Service Morristown TN
300 PM EDT Wed Jul 24 2024

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(This evening through Thursday)
Issued at 254 PM EDT Wed Jul 24 2024

Key Messages:

1. Periods of showers and a few thunderstorms remain possible
while temperatures remain seasonally cool through the short term.

Discussion:

Upper troughing with a southwest to northeast oriented H3 jet of 85-
100kts remains placed over the Ohio Valley region. Lobes of
vorticity and upper level divergence associated with the right
entrance region of this jet are working with weak surface
convergence to develop numerous to widespread showers across
portions of Tennessee into northern sections of our bordering Gulf
States. CAM guidance generally depicts a lull in activity late
this evening to just after midnight followed by an additional
uptick in activity with a secondary shortwave/vort lobes during
the overnight hours into Thursday morning. Thursday morning into
Thursday afternoon trends suggest that the greatest precip chance
will generally be south and east of the I-40 & I-81 corridors.

SPC Mesoanalysis and RAP soundings depict MLCAPE will remain around
700J/kg or less through this period, which will act to limit precip
efficiency and overall threats with this activity. However, given
recent rains saturating soil and potential training of storms that
may produce upwards of 1" hour rain rates, very isolated flooding
cannot be totally ruled out. Believe the low probability wording in
the HWO is good and will continue to roll with that. Temperatures
will remain slightly below seasonal normals through the period.

&&

.LONG TERM...
(Thursday night through next Wednesday)
Issued at 254 PM EDT Wed Jul 24 2024

Key Messages:

1. Chances for showers and storms during the entire period, but less
coverage is expected across the north Friday into Saturday.

2. High temperatures should be near to a bit below normal.

Discussion:

Models continue to show an overall moist pattern for the long term
period. We start the period Thursday night with an upper trough over
the Great Lakes region and upper ridging to our southeast and also
to our west. The upper ridge will build east during the weekend then
flatten out and retrograde to our southwest as another upper trough
digs into the eastern US late in the period. No big airmass change
is expected through all of this, but some limited drying is
currently expected to work in early in the period especially north
which may bring less convective coverage Friday into Saturday
across at least the north.

Overall we will see chances for showers and thunderstorms throughout
the extended period. Right now the highest chances look to be Sunday
and especially Monday/Tuesday as the upper ridge is replaced by
troughing.  High temperatures are generally expected to run near to
slightly below normal.

&&

.AVIATION...
(18Z TAFS)
Issued at 140 PM EDT Wed Jul 24 2024

Unsettled weather with periods of showers and potential isolated
storm possible for the 18Z TAF cycle. Confidence is honestly low,
especially in regards to cig height and fog, but periods of MVFR
to IFR reductions in flight categories are possible. Notably
early Thursday morning when CAM guidance suggest a secondary
period of activity will move through.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             71  83  71  85 /  50  60  20  50
Knoxville McGhee Tyson Airport, TN  70  83  70  84 /  60  60  20  50
Oak Ridge, TN                       69  83  69  84 /  50  60  20  50
Tri Cities Airport, TN              68  81  68  84 /  60  60  20  30

&&

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

SHORT TERM...KRS
AVIATION...KRS

Hazardous Weather Outlook
National Weather Service Morristown TN
257 PM EDT Wed Jul 24 2024

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-251900-
Cherokee-Clay-Scott TN-Campbell-Claiborne-Hancock-Hawkins-
Sullivan-Johnson-Morgan-Anderson-Union-Grainger-Hamblen-
Northwest Cocke-Cocke Smoky Mountains-Northwest Greene-
Southeast Greene-Washington TN-Unicoi-Northwest Carter-
Southeast Carter-Roane-Loudon-Knox-Jefferson-Northwest Blount-
Blount Smoky Mountains-North Sevier-Sevier Smoky Mountains-
Sequatchie-Bledsoe-Rhea-Meigs-McMinn-Northwest Monroe-
Southeast Monroe-Marion-Hamilton-Bradley-West Polk-East Polk-Lee-
Wise-Scott VA-Russell-Washington VA-
257 PM EDT Wed Jul 24 2024 /157 PM CDT Wed Jul 24 2024/

This Hazardous Weather Outlook is for portions of southwest North
Carolina...east Tennessee and southwest Virginia.

.DAY ONE...This Afternoon and Tonight

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not needed at this time.