234 
FXUS64 KMRX 071151
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
651 AM EST Sat Mar 7 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 647 AM EST Sat Mar 7 2026

- A line of showers and storms is expected to move through the
  area late this afternoon through the evening hours. Isolated 
  damaging wind gusts are possible, especially in western areas. 

- Off and on chances for showers and storms continue Sunday
  through Wednesday with Wednesday evening having the best chance
  for storms.

- Near record heat is likely Saturday and then Monday through
  Wednesday.  

&&

.DISCUSSION...
Issued at 103 AM EST Sat Mar 7 2026

Currently, troughing and a downstream jet is well to our northwest 
with a surface low moving into the upper Mississippi River Valley. 
This system is an open wave with its warm front along the Great 
Lakes and cold front extending into the Great Plains. Initially, the 
region will remain under the influence of broad ridging and 
southerly flow that will promote a continuation of record heat 
during the day today: 

Daily Record High Maximum Temperatures

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge 
03-07   82(2000)       80(1983)       79(1956)       80(1956) 
  
With initially drier air, much of the area will remain dry through 
the morning and into part of the afternoon. The 850mb jet, while not 
as strong as to our north, will still be in excess of 30 kts and 
produce a breezy day area-wide. Wind gusts to 30 mph or greater will 
be common but still likely below advisory criteria. By later in the 
afternoon, moisture will advect from the southwest as the front 
moves into the Ohio River Valley. While flow will be fairly 
unidirectional, the environment will still consist of effective 
shear reaching to 35 kts and SBCAPE exceeding 1,000 J/kg. Low-level 
shear, driven mostly by speed, will also reach 20 kts or greater. 
The latest CAMs show a QLCS arriving to the Cumberland Plateau by 
about 5 PM EST and then moving through central portions of the area 
within 2 hours before exiting later in the evening. This timing will 
lead to lessened instability than places to the north and west but 
still with enough to support the marginal severe weather risk. The 
850mb jet will only be around 30 to 35 kts during this time, but the 
intensity of the line could certainly produce damaging winds, 
especially in western portions of the area. Small hail is possible, 
but instability will be diminishing in the growth region. Regarding 
tornado potential, LCL heights above 1,000m and limited directional 
shear will keep the threat minimal in our area. 

Behind the main line, stratiform rain or even showers are shown to 
linger overnight with the frontal boundary arriving just to our 
northwest by Sunday. This will keep rain chances elevated on Sunday 
with instability having largely pushed off to our southeast. 
Temperatures will also be moderated back below record values. By 
Monday, the flow aloft will become more zonal with a closed low 
moving over northern Mexico. Downstream of this closed low will be a 
jet of nearly 100 kts with the left exit region, pulling the front 
back northward. This will promote another increase in rain chances 
by the evening. On Tuesday, the jet merges with a broad upper jet to 
the north, broadening southerly flow and WAA as another system will 
develop and track to the Great Lakes region. Potential record 
temperatures will also come back into view:

Daily Record High Maximum Temperatures

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge
03-09   82(2009)       82(1925)       79(2016)       80(1974)       
03-10   81(2009)       81(2016)       82(2016)       81(2016)       
03-11   81(2006)       81(2006)       78(2006)       80(1990)  

The frontal boundary will gradually move into the area by Wednesday 
evening into Wednesday night, leading to another chance for showers 
and storms. Based on the model outputs and overall timing, this 
environment would be more of a higher shear / lower CAPE scenario 
than with the first system. As such, an earlier timing would be more 
favorable for severe chances, but the latest trends keep this 
largely to our west. It will be worth watching nonetheless. The 
front will move through by later in the week, leading to a return of 
cooler and drier conditions.

&&

.AVIATION...
(12Z TAFS)
Issued at 647 AM EST Sat Mar 7 2026

No significant changes. Winds aloft have weakened. Tacked in a
PROB30 late in the period at TYS and TRI to account for
uncertainties in overnight rainfall. Ceilings area wide are likely
to drop to MVFR conditions late in the period. A line of TSRA this
evening is likely to bring brief significant drops in conditions 
as the storms pass over the terminals.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             81  61  74  58 /  60  90  60  20 
Knoxville McGhee Tyson Airport, TN  80  61  72  56 /  60  90  70  20 
Oak Ridge, TN                       78  60  71  55 /  70  90  60  10 
Tri Cities Airport, TN              79  59  68  52 /  50  90  70  10 

&&

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

$$

DISCUSSION...BW
AVIATION...Wellington


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