654
FXUS64 KMRX 262325
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
725 PM EDT Fri Jul 26 2024

...New AVIATION...

.SHORT TERM...
(This evening through Saturday)
Issued at 221 PM EDT Fri Jul 26 2024

Key Messages:

1. Showers and thunderstorms continue this afternoon with the
greatest coverage likely to be south of I-40.

2. Another round of showers and possibly thunderstorms will occur
tomorrow.

Discussion:

Currently the initial round of light showers moving through the
central valley is running into the drier airmass in northeast TN and
southwest VA. Expect this trend to continue with only isolated
drizzle expected north of Interstate 40. More robust convection is
moving along near the southern TN border. There is some enhanced
moisture convergence and slightly better synoptic forcing on the
southern edge of the trough moving through. With some clearing in
the clouds across southeast TN this afternoon these storms could
move into some enhanced instability as they move further to the
east. MLCAPE values could exceed 1,000 J/kg in this area. Biggest
threats with the strongest storms would likely be gusty winds and
brief heavy downpours leading to localized flooding of poor
drainage areas.

Moving into the overnight hours expect the convection to quickly die
off once the sun begins to set leading to a fairly calm overnight
period. Expect another round of patchy fog in our region with the
higher dew points and recent rainfalls. Tomorrow will see another
warm and humid day with afternoon showers and thunderstorms possible
once again.

&&

.LONG TERM...
(Saturday night through next Friday)
Issued at 221 PM EDT Fri Jul 26 2024

.LONG TERM...(Saturday Night through Friday)

Key Messages:

1. An unsettled pattern with daily chances of showers and storms is
expected through the long term.

2. Localized flooding is possible due to repeated, potentially heavy
rainfall, especially Monday.

Discussion:

Come Sunday, we will find ourselves under brief ridging squished
between shortwave troughing to our west and a developing cutoff low
off the east coast. This will allow for increasing moisture
advection into the region with PWAT increasing to upwards of 2
inches in portions of the central and southern valley. Vort maxima
and isentropic lift will lead to numerous to widespread showers and
storms Sunday and Monday. Model derived soundings suggest tall &
skinny CAPE profiles with freezing levels between to 13 to 14kft may
very well promote periods of efficient warm rain processes. This
will lead to increased flooding potential, especially for Monday, in
which a large portion of our area of responsibility remains
highlighted in a slight risk ERO. A limiting factor to the flooding
threat may be fairly meager MLCAPE values less than 1000J/kg,
however, soundings also suggest corfidi upshear values less than
10kts are possible and potential for slow moving or back building
storms will need to be monitored.

Quasi-zonal flow with bouts of upper level disturbances is expected
Tuesday onwards. This will promote continued daily chances of
showers and storms through the extended period. A continued threat
of flooding is a little less clear given a lack of real significant
upper level features but poor antecedent conditions may allow the
flooding threat to persist throughout the week as well. Temperatures
mid to late week will also be trending warming, with thermodynamic
profiles becoming increasingly favorable for more thunderstorm
activity and potential gusty winds and small hail with stronger
storms. Slightly above normal temperatures are expected to return in

&&

.AVIATION...
(00Z TAFS)
Issued at 721 PM EDT Fri Jul 26 2024

Mostly VFR conditions are expected this TAF cycle. Some fog
development is possible in the early morning hours, mainly near
TRI where clearing is expected. High clouds will hang around
longer for TYS/CHA. Hit and miss showers are likely mainly near
TYS/CHA in the afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             71  88  73  87 /  20  50  10  70
Knoxville McGhee Tyson Airport, TN  68  88  71  88 /  20  40  10  60
Oak Ridge, TN                       68  88  70  86 /  10  40  10  60
Tri Cities Airport, TN              65  87  65  88 /  10  20   0  30

&&

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

$$

SHORT TERM...
LONG TERM....KS
AVIATION...McD