291 
FXUS64 KMRX 271834
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
234 PM EDT Mon Apr 27 2026

...New DISCUSSION...

.KEY MESSAGES...
Updated at 233 PM EDT Mon Apr 27 2026

- Showers and thunderstorms will move into the area late tonight/early
  Tuesday morning. Isolated strong/severe storm possible mainly 
  Plateau and southeast Tennessee. Main threat will be strong and 
  gusty winds.

- Windy conditions for the far east Tennessee mountains/foothills 
  tonight/early Tuesday morning. Gusts up to 50 mph possible.

- Periods of showers and thunderstorms likely late Tuesday into 
  Wednesday. Potential of strong to severe storms but timing, 
  intensity, and extent of the severe thunderstorms remain low.

- Another round of mainly rain showers expected Friday through 
  Saturday. Thunder chances are quite low.

&&

.DISCUSSION...
Issued at 233 PM EDT Mon Apr 27 2026

Currently, a wedge of high pressure across the eastern seaboard is 
slowly pulling drier low-level moisture into east Tennessee, 
southwest Virginia, southwest North Carolina. Latest HREF/HRRR model 
shows dewpoints dropping into the 40s to lower 50s this evening with 
some upper 30s possible over southwest Virginia. 

This wedging will east of the Appalachians and low pressure over the 
mid-west/upper Ohio valley will produce fairly tight pressure 
gradients overnight. As the low-level inversion estabilishes itself 
this evening. HREF and HRRR shows mountain wave winds developing 
with southeast winds increasing to 15 to 30 mph with gusts up to 50 
mph possible. A wind advisory has been issued.

Upper divergence will move across the region with strong convection 
over the mid-west/western Ohio valley moving east southeast into the 
Tennessee valley overnight/early Tuesday morning. This line of 
convection will weaken as it moves into the more stable airmass over 
the area. However, mid-level lapse rates of 7-7.5 degrees C will 
produce elevated instability allowing for the threat of strong to 
severe storms over the Plateau and southeast Tennessee early Tuesday 
morning. Main concern will be damaging winds and small hail.

For Tuesday, post short-wave subsidence and developing mid-level cap 
will limit convection much of the day. Morning clouds will give way 
to more sun in the afternoon. 

For Tuesday night, a stronger short-wave and upper jet will produce 
good synoptic forcing. Depending on how the airmass can destabilize 
ahead of the next system and return flow of southerly winds, a great 
threat of severe storms is expected especially for the Plateau and 
southeast Tennessee. Main concern will be damaging winds and large 
hail. 

For Wednesday, there is another potential of severe storms as 
frontal boundary will be across the region during the day. Depending 
on how much breaks in the clouds, ensembles and latest deterministic 
runs show mid-level lapses rates of 7+ degree/C, decent hail growth 
CAPE, and effective bulk shear of 40-50 knots to produce 
strong/severe storms. Shear and Instability show the greatest 
potential of organized severe storms, but confidence remains low of 
the intensity and extent of the thunderstorms but will monitor 
closely.

For Thursday and part of Friday, surface ridging will produce drier 
conditions.

For the later half of Friday through Saturday, ensembles and 
deterministic models are becoming in better agreement with a 
southern stream wave moving across the Gulf Coast states and 
Tennessee valley. Strong jet dynamics will produce widespread/much 
needed rainfall across the southeast United States, possibly into 
the Tennessee valley/southern Appalachians as well. Surface low will 
move well south of the region with little to no instability. Expect 
mainly shower activity. 

Surface ridging and drier conditions for Sunday and Monday.

&&

.AVIATION...
(18Z TAFS)
Issued at 125 PM EDT Mon Apr 27 2026

Main Aviation Forecast concern is the expected showers and
thunderstorms for early Tuesday morning. Some of these storms
could produce strong and gusty winds. Otherwise, as the line of
convection moves across the region ceiling will drop to marginal
MVFR conditions from 10-16Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             59  77  64  80 /  60  60 100  90 
Knoxville McGhee Tyson Airport, TN  58  76  61  76 /  60  60  90 100 
Oak Ridge, TN                       57  75  60  76 /  70  60  90 100 
Tri Cities Airport, TN              53  73  58  71 /  60  70  80 100 

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...Wind Advisory from 8 PM this evening to 8 AM EDT Tuesday for 
     Blount Smoky Mountains-Cocke Smoky Mountains-Johnson-Sevier 
     Smoky Mountains-Southeast Carter-Southeast Greene-Southeast 
     Monroe-Unicoi.

VA...NONE.
&&

$$

DISCUSSION...DH
AVIATION...DH


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