Scientific Forecaster Discussion
fxus64 kohx 151725
Area forecast discussion
National Weather Service Nashville Tennessee
1225 PM CDT Mon Jul 15 2019
for 18z aviation discussion.
This forecast period again largely revolves around dealings
of decaying tropical system Barry. The center is currently across
southwest Arkansas...and a northward track is expected to continue
today, with a turn northeast on Tue. Tue night, associated upper
low opens and its then upper trough axis will move across the mid-
state Wed into early Thu.
This will keep our weather unsettled into at least late week. As
for today...areas west of I-65 are likely to see most widespread
pcpn as remnants pushes up through Arkansas. Parameters are marginal
most of the area but are elevated enough for a few strong storms
across the west today. Similar parameters exist of Tue as well,
although instability is a bit higher than today, meaning scattered
showers/storms roll on and are expected to be a bit more numerous.
Parameters are more enhanced on Wed as well, which is when the
bulk of what remains of Barry is expected to affect the mid-state.
Early in the day, with ml/ul trough approaching, both shear and
instability ramp up a good bit, and moisture remains very deep.
While the threat of severe storms seems low end, precipitable
water values go above 2, giving US potential for some very heavy
rain. There appears to be a weak surface/ll boundary pushing through
as well. This boundary seems to be moving but there is at least a
small threat of flash flooding into Wed night.
Upper trough is east of US on Thu, with ridging building in
behind. GFS however continues to be much wetter than the Euro,
really Fri and right on through the weekend. GFS even brings
down a bonafide front on Mon, which again the Euro has a much
more washed out version of. Seems compromise of smaller pops
warranted at times late in the period...especially east of I-65.
18z taf discussion.
Light shower activity across middle Tennessee as a result of Barry
will continue to bring minimal impacts to all taf sites through
tonight. Ckv has best chance of seeing more persistant shower
activity, with possible -tsra this afternoon as a heavy band of
convection noted across northwest Alabama tracks northward, but
west of bna and mqy. Otherwise expect VFR through the forecast
period, with stronger south-southwesterly winds and more shower