473 
FXUS64 KMRX 210647
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
247 AM EDT Sat Mar 21 2026

...New DISCUSSION...

.KEY MESSAGES...
Updated at 241 AM EDT Sat Mar 21 2026

- Scattered showers and storms are possible late this afternoon 
  and evening. The main threat with these storms will be hail. 

- Warm and breezy on Sunday with a low chance of rain returning 
  Sunday night/Monday morning. 

- Dry and seasonally cooler conditions are expected Monday until a
  warming trend and returning rain chances late in the week.

&&

.DISCUSSION...
Issued at 241 AM EDT Sat Mar 21 2026

A surface front will be pushing southward across the OH Valley 
today, while a weak shortwave trough will approach in the NW flow 
aloft. The front is expected to be positioned near the TN/KY
border by the afternoon when the trough crosses the MS River. 
CAMS are coming into better agreement on the development of 
convection south of the front in the Cumberland Plateau area, 
mainly around 4-6 PM. The convection tracks SE into the central TN
Valley through the evening. Given the midlevel lapse rates of 
around 7-8 C/km, low WBZ height below 10k ft, and MLCAPE around 
1000-1200 J/kg, hail appears to be the main threat from storms. 
Winds aloft are not particularly strong (20-30 kt up to 500 mb) 
for damaging winds, but an inverted V profile in NAM soundings 
suggest evaporative cooling could enhance wind gusts. Most of this
activity should be over by 10 PM. 

The front lifts northward on Sunday as a low pressure system tracks 
across the central Plains. This will keep our area in a warm SW flow 
through the low levels, and highs on Sunday will be well above 
normal - in the lower to mid 80s in most spots. This will be within 
a few degrees of record highs - the TRI record of 81 could be tied 
or broken. That low pressure system and its associated cold front 
will cross our area on Monday, with a low chance of showers/storms 
ahead of it late Sunday night/Monday morning. Instability in the 
morning appears too limited for any strong/severe storms, and the 
chance of showers will mainly be north of I-40. 

Daily Record High Maximum Temperatures
Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge          
03-22   89(1907)       87(1907)       81(1938)       83(2011)   

A colder air mass will build into the area on Monday behind the cold 
frontal passage. High pressure over the Great Lakes and OH Valley 
region will promote drier and seasonally cooler conditions through 
Tuesday. By Wednesday, broad ridging will expand from the southwest 
with high pressure shifting eastward, leading to a return of 
southerly flow and increasing moisture and WAA. Low-end rain chances 
return late in the week as a front settles somewhere in the TN/OH
Valley region. The position of a large high pressure ridge across
the Gulf Coast region will mean moisture will be limited, but we 
could have several days with rain chances late in the week as the 
front remains nearly stationary and parallel to the midlevel flow.

&&

.AVIATION...
(06Z TAFS)
Issued at 140 AM EDT Sat Mar 21 2026

VFR can generally be expected outside of any precipitation. CHA
likely to stay dry. LLWS kept at TRI during the overnight hours. 
Possible leftover precipitation from the north will reach TRI 
later this morning. PROB added at TYS for the later afternoon and
evening with possible development of storms later tonight. The
near-storm environment doesn't appear that damaging winds will be
much of a threat, mainly hail.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             85  58  86  62 /  10  10   0  10 
Knoxville McGhee Tyson Airport, TN  80  60  84  58 /  40  40   0  20 
Oak Ridge, TN                       80  58  84  58 /  30  40   0  30 
Tri Cities Airport, TN              73  55  80  54 /  20  20   0  50 

&&

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

$$

DISCUSSION...DGS
AVIATION...KS


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