Scientific Forecaster Discussion
fxus64 kohx 201127
Area forecast discussion
National Weather Service Nashville Tennessee
627 am CDT Thu Jun 20 2019
for 12z aviation discussion.
Rain and thunderstorms are with US once again, bringing pockets
of heavy rainfall, lots of lightning, and some gusty winds. Most
of these have remained below severe limits, but with a 30-40 kt
low-level jet and remnant instability from yesterday, a couple
storms could still become severe through the morning. Otherwise,
expect wet roadways for the morning commute with lingering rain
and scattered thunderstorms. Current radar trends would suggest
that the heaviest activity will remain south of I-40 over the next
couple of hours. However, further development in west Tennessee and
persistent cam guidance suggests that more scattered convection
will continue from mid morning through the early afternoon...especially
for locations along and north of I-40. This will be monitored
over the next few hours, but the severe threat should generally
More showers and a few thunderstorms are advertised in the models
for this afternoon, especially across the Cumberland Plateau.
Widespread severe storms are not expected but gusty winds and
heavy rainfall are possible. Most of US will dry out by mid
afternoon and early evening, remaining dry through the first half
of Friday. 00z GFS/Euro guidance are not in agreement for Friday,
with the GFS wet and the Euro almost completely dry. A warm front
will be slowly pushing northeast through the mid state, providing
the focus for rain and storms to develop. With increasing
instability along and west of the front, Storm Prediction Center has included the
northwestern third of our County Warning Area in a marginal risk for severe
weather. There is a signal, now in the GFS and ECMWF, that a
complex of storms will race south into our area Saturday morning.
Storm Prediction Center has mention of a potential mesoscale convective system and has included northern and
eastern portions of our County Warning Area in a marginal risk...still
highlighting quite a bit of uncertainty in regard to convective
development and evolution. Otherwise, scattered storms during the
afternoon will taper off after sunset. Rain and storms will be
maximized Sunday afternoon and especially Monday afternoon/evening
as a longwave trough pushes across the Ohio/Tennessee valleys. We will be
on the mend Tuesday and finally have a dry day Wednesday.
Temperatures will be near or slightly above normal over the next
seven days, with heat indices nearing 100 on Saturday and Sunday.
High pressure looks to settle into the region mid to late week,
keeping rain chances to a minimum.
12z taf discussion.
Showers and an occasional thunderstorm will continue to move
through the mid-state this morning with only brief reductions to
MVFR visible and ceilings anticipated. By the late morning hours
conditions should improve though MVFR ceilings may linger into the
afternoon. Southwesterly wind gusts of 20 to 25 kts will taper
toward sunset, with decreasing cloud cover overnight.