FXUS64 KMRX 042319
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
719 PM EDT Tue Aug 4 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 716 PM EDT Tue Aug 4 2026

- Scattered showers and storms are expected this afternoon, with
  greatest coverage in and along the higher terrain. A few storms
  could produce strong gusty winds, localized flooding, and small
  hail.

- Daily chances of showers and storms will continue each day
  through the forecast period, primarily favoring the afternoon
  and evening hours. A low chance for localized flooding exists
  each day.

- Near normal temperatures are expected for the next several days.

&&

.DISCUSSION...
Issued at 236 PM EDT Tue Aug 4 2026

An upper level low has developed over the southeastern CONUS, while
a shortwave trough is ejecting northeast in vicinity of Nova Scotia
and an additional trough digs into the northern Plains. A weak
southern stream vort max will promote a retrograding stationary
boundary in the Piedmont this afternoon. The vort max and front will
aid diurnal convective initiation within an environment of ~1500J/kg
MLCAPE, 1.5-1.7 PWs, and weak steering flow. Latest 1 hr ffgs range
from 1.4-1.8 inches in the foothills and East Tennessee mountains,
increasing to around 1.8-2.3 inches in southeast Tennessee and
southwest North Carolina. While on the weaker side, latest
mesoanalysis depicts a local increase in sfc-H85 convergence where
storms have notably strengthened over the last 30 minutes. Main
threats for this afternoon will be isolated strong to damaging winds
gusts and localized flooding, but some of the tallest storms could
exhibit small hail as well.

Upper low is expected to remain in place across the region tomorrow
afternoon, and slowly phase into mean flow aloft Thursday into
Friday. However, the aforementioned troughing over the Northern
Plains will be working into the Great Lakes region, maintaining weak
upper level divergence across the southern Appalachians. Diurnal
heating in a moist environment will ultimately promote continued
chances of diurnal convection through at least the remainder of the
weekend. With each day, isolated flooding could pose a threat with
any slow moving storms that track over already saturated soils or
want to latch onto terrain features. While the potential for some
valley convection is possible, the greatest coverage is largely
expected in areas of enhanced orographic lift.

As we head into next week, the latest ECMWF depicts enhancement of
the low-level jet across the the northern Ohio Valley. This will
continue the chance for daily showers and storms, but long range
deterministic models are not in agreement with the coverage. GFS
is more bullish while the ECMWF is and the lower side. Latest NBM
is bridging that gap with 40-50% PoPs. CIPS analogs keep the
better chances for severe weather to our north and east in closer
proximity to the strong synoptic forcing and enhanced shear.

&&

.AVIATION...
(00Z TAFS)
Issued at 716 PM EDT Tue Aug 4 2026

Scattered showers and thunderstorms on radar, though likely KTYS
and KTRI are done for the day. A few lingering TCUs potentially
yielding TS are near KCHA, so kept a short VC group in for that
possibility. Otherwise overnight is likely quiet, maybe an
isolated shower. Patchy fog potentially before and at daybreak,
not confident yet on inclusion, but mentioned it at KTRI, where it
is usually more favorable for fog formation. Tomorrow similar
weather setup, with scattered showers and TS again in the late
afternoon to the end of the TAF period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             71  88  72  90 /  20  60  20  60
Knoxville McGhee Tyson Airport, TN  70  86  71  87 /  20  60  10  60
Oak Ridge, TN                       70  86  70  87 /  20  50  10  70
Tri Cities Airport, TN              67  83  67  83 /  10  60  20  70

&&

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

$$

DISCUSSION...KRS
AVIATION...Wellington