Scientific Forecaster Discussion
fxus64 kohx 221140
Area forecast discussion
National Weather Service Nashville Tennessee
640 am CDT Fri Sep 22 2017
for 12z aviation discussion.
(today thru sun)
With no frontal passages expected through Sunday, the upper levels
will govern our weather. Today, an upper ridge will stretch from Texas
NE across the Great Lakes region. A very weak northeasterly ul flow
will prevail but heights will be elevated with a 00z tendency toward
weak subsidence in the lower levels. Therefore, will not include any
pops for today.
The lower dewpoint depressions will back off a bit over the next 2
overnights and thus, no fog inclusion in the grids.
On Saturday, the upper ridge will shift its focus northward and
begin to elongate W-E. More of an easterly flow will set up with an
easterly wave centered over the Gulf Coast. "Maria" will be located
over the western Atlantic, a couple hundred miles east of the
Bahamas, and will steal much of the moisture as she moves northward.
We do see some weak pva over the mid state Sat aft so will include
low chances of showers and tstms. We should see a westward drift
with any storms that do develop.
On Sunday, the pattern changes little from Saturday. Mid/upper level
temps may cool a degree or two. Hence, low pops again.
For the near term temps, near 90 for the next 2 days. On Sunday,
heights lower just enough to knock our highs down into the upper
80s. Overnight lows will be primarily in the upper 60s.
(mon thru thu)
Expect dry conditions thru the first half of next work week as sfc
and upper level ridging influences continue. No anticipated impacts
from Hurricane Maria at this time to the mid state region.
Eventually, ridging influences will break down with a sfc frontal
passage occuring late Wed night into Thu. A slight chance of light
shwrs/tstms near the Land Between The Lakes region is expected on
Wed night. A slight chance of light showers and thunderstorms will
be in store for the entire mid state on Thu.
As for temps, they will remain seasonably mild until Thu afternoon.
Highs will be in the mid to upper 80s, lower 80s Cumberland Plateau
region. Overnight lows will be in the mid 60s, lower 60s Cumberland
Plateau region. Sfc frontal passage late Wed night into early Thu
will result in afternoon high temps much closer to seasonably normal
values on Thu afternoon.
12z taf discussion.
Ckv/bna/mqy/csv...with obs continuing to be sporadic at mqy, will
continue mention of amend not schedule to end of mqy taf. Otherwise, at
terminals, IFR/MVFR fog induced vsbys should persist generally
thru 22/14z. Ridging influences sfc/aloft should prevail thru
23/12z with the development of sct cumulus fields after 22/14z. MVFR to
IFR fog induced vsbys should return to terminals 23/04z-23/12z.