343 
FXUS64 KMRX 170620
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
220 AM EDT Sun May 17 2026

...New DISCUSSION, AVIATION...

.KEY MESSAGES...
Updated at 149 AM EDT Sun May 17 2026

- Very warm temperatures are expected the rest of this weekend
  into this upcoming week. Many places will reach near 90 degrees
  Sunday through Tuesday. 

- More widespread chances for showers and storms return Wednesday
  through Friday with temperatures back closer to normal.

&&

.DISCUSSION...
Issued at 149 AM EDT Sun May 17 2026

Main weather feature for Sunday into early next week will be an 
upper ridge over the southeast United States into the southern 
Appalachians. Main impact will be unseasonably very warm 
temperatures especially for Sunday through Tuesday. Highs will be 10 
to 15 degrees above normal.

For Sunday, HREF and deterministic models are coming into agreement 
with a mid-level wave and increased 700-850mb winds rotating 
northward from Georgia into east Tennessee/southern Appalachians. 
HREF shows PWs increasing with CAPES of 1000-1500 in the afternoon. 
Isolated to widely scattered showers and thunderstorms are possible 
by late afternoon/evening especially across the higher elevations 
and near the Georgia state-line. Airmass will be charactered by high 
cloud base with decent mid-level dry air and lapse rate. These 
features may produce isolated strong/gusty winds. HREF also denotes 
the possibility of strong winds with the stronger storms. Low 
confidence but possible.

This wave moves out of the area Sunday evening with upper ridge with 
associated subsidence for Monday and Tuesday. Very warm and 
mostly dry conditions. Highs will be 10 to 15 degrees above 
normal.

For Wednesday, the upper ridge weakens over the region with a weak 
frontal boundary approaching the area late. Boundary layer flow 
becomes more southerly pulling slightly deeper moisture into the 
region. Scattered showers and storms may accompany the incoming 
front. Instability remains marginal with CAPES of 1000 with limited 
shear. At this time, strong to severe storms are not anticipated.

For Thursday through Saturday, a series of short-wave ejects 
northeast from Texas/mid-Mississippi valley into the Ohio/Tennessee 
valleys. Deeper moisture combined with these waves and possible 
frontal boundary near the area will produce periods of scattered 
showers and storms. Low confidence on timing of convection. Ensemble 
QPF suggests between 0.6-1.2 inches.

&&

.AVIATION...
(06Z TAFS)
Issued at 149 AM EDT Sun May 17 2026

VFR and primarily dry conditions are likely today. There's a low
chance for an isolated thunderstorm or two late in the afternoon
and into the early evening hours, PROB30s were added to TYS and
CHA to account for this scenario. Winds will remain generally
light, with a few gusts to 15 knots again at TYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             90  65  89  67 /  10  10  20  10 
Knoxville McGhee Tyson Airport, TN  90  65  90  66 /  10   0  10   0 
Oak Ridge, TN                       89  63  89  64 /  10  10  10   0 
Tri Cities Airport, TN              87  60  90  61 /   0   0  20   0 

&&

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

$$

DISCUSSION...DH
AVIATION...Wellington


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