Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Nashville Tennessee
718 am CDT Sat Aug 23 2014
Update...for 12z tafs.
upper ridge prognosticated to retrograde next 24hrs while moisture stays
fairly deep. Additionally...weak surface boundary will remain in the
immediate area and that will allow isolated-scattered storms to develop. Best
chance will be in the csv vicinity as upper high moves west. Little
storm development expected later this evening/tonight but fog likely
to form...especially overnight.
Previous discussion... /issued 257 am CDT Sat Aug 23 2014/
small complex has now worked south of the Ohio River and down into
west central Kentucky at 0730z. Complex has been working along
eastern periphery of strong upper ridge. Cloud tops have warmed a
little last hour and expect this trend to continue. H-triple-r drives
this complex down along Kentucky border between 09z-10z time
frame and plays it out...with only isolated to scattered showers
down into the Nashville area between 10z-12z. As complex plays out
this morning look for clouds to linger a while across northern
middle Tennessee which will give temperatures a slower diurnal start.
Most of middle state will be on eastern side of upper ridge today as
surface front tries to backdoor into plateau during the afternoon
and evening with scattered thunderstorms developing. Similar
scenario tonight and Sunday into Monday as middle state will remain
on eastern periphery of upper ridge and frontal boundary will be
nearby. Thus will keep at least a 20-30 percent of showers and
thunderstorms on-going. So warm humid conditions will prevail for
the next several days with heat indices triple digits west of
Interstate 65 today and more widespread on Sunday and in far
western middle Tennessee on Monday. Believe middle state will remain
below heat advisory criteria as we go through the weekend with the
northwest corner having the highest. Models keep upper ridge in
place through about middle week then develops a trough through
Mississippi River valley with GFS being more aggressive and faster
with this. Also...possible tropical development off eastern U.S.
Latter part of work week.
heat advisory from noon today to 9 PM CDT this evening for