Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
FXUS64 KMRX 290814
Area Forecast Discussion
National Weather Service Morristown TN
414 AM EDT Wed Mar 29 2017
.Short Term (Today and Tonight)...Ridging between weather systems
will mark the short term. Warm temperatures of 10-12 degrees above
normal are expected, with fair weather. Light winds today will
become southerly overnight. Upslope precipitation on the NC side of
the mountains late tonight may flirt with TN mountain communities on
the state line, but will maintain the non-mention of precip.
.LONG TERM (Thursday through Tuesday)...Main concern is a strong
upper trough lifting east fro the central/southern Plains into the
Tennessee Valley Thursday and Thursday night. Strong jet streaks
will move across the upper low across the Tennessee Valley with
broad upper divergence across the Region. The circulation around
these jets will produce strong upper forcing across the Tennessee/
Mississippi Valleys. In response to the upper forcing, a strong
low-level jet will develop as well with 850mb winds of 50-60kts
pulling abundant moisture/instability into the Tennessee Valley,
especially the western and middle Tennessee.
Very favorable environment for tornadoes development with good
shear and thermodynamics over the western half of Tennessee
Tennessee and Mississippi Valley with long-lived tornadoes
anticipated. Main question for the Plateau and southeast Tennessee
is if these tornadic supercells can make into this far east into
lesser environment. CIPS analogs suggests there is a threat into
the Plateau and southeast Tennessee with SPC pulling a slight risk
into these areas. For the central Valley, there is a threat of
damaging winds as these storms weaken with a marginal risk.
For the northern half of Tennessee Valley into southwest Virginia,
the strong southerly low-level jet will produce downsloping
conditions limiting convection. The strong low-level jet combined
with favorable thermodyanmic conditions will set the stage for
mountain wave high winds for the far east Tennessee Mountains and
foothills for late Thursday through early Friday morning.
This system moves east of the area Friday morning, but wrap-around
showers will continue for the northern/eastern areas Friday
afternoon and night.
Upper ridging returns for Saturday and Sunday with the next strong
upper trough expected for Monday and Tuesday. Strong dyanmics with
this system as well with showers and storms likely.
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 80 58 80 59 / 0 10 30 80
Knoxville McGhee Tyson Airport, TN 76 55 76 57 / 0 10 20 80
Oak Ridge, TN 77 55 77 57 / 0 0 20 80
Tri Cities Airport, TN 73 50 73 54 / 0 10 20 70
TN...High Wind Watch from Thursday evening through Friday morning for
Blount Smoky Mountains-Cocke Smoky Mountains-Johnson-Sevier
Smoky Mountains-Southeast Carter-Southeast Greene-Southeast