Area Forecast Discussion
Issued by NWS Nashville, TN
FXUS64 KOHX 231145
Area Forecast Discussion
National Weather Service Nashville TN
645 AM CDT SAT JUL 23 2016
FOR 12Z AVIATION DISCUSSION.
Scattered convection winding down along the Tennessee River at
08z. Looks like capping underway in RAP from southeast Missouri
across southern Illinois into southwest Indiana as 700 mbar temps
in excess of +12 degrees...with western Kentucky down through
western Tennessee on the edge of the lid. Air mass across Middle
Tennessee is juiced up pretty good with precipitable water around
2 inches which is a little shy of 2 standard deviations for July
based on 1948-2010 Nashville integrated surface to 300 mbar
precipitable water. MUCAPES climb to around 1500 joules per
kilogram in the afternoon heat today so expect to see some
scattered convection once again. Have backed off on the high
temps for today from what we had forecast yesterday for today but
heat indicies will still be above 100 west of plateau with a few
above 105 back along the Tennessee River this afternoon. So will
leave heat advisory going even though some areas may not
technically reach criteria impact will be similar. Will keep a
small pop for the evening then drop pops for the overnight hours.
On Sunday look for scattered convection once again developing with
temps up in the low 90`s west of the plateau. By Monday upper
ridge will have retrograded enough to allow for a frontal boundary
to begin approaching from the northwest and this will allow for
convection to increase across the area with thunderstorm chances
right on the through the work week continuing into the weekend as
surface front doesn`t make it through Middle Tennessee but stays
within proximity and air mass remains moist and warm while a
series of mid and upper level disturbances traverse the area. Max
temps next week should be closer to climatology but lows at night
will be averaging 5 to 7 degrees above normal. Normal high for
Nashville this time of the year is 89 with low of 68.
12Z TAF DISCUSSION.
Fog along the plateau this morning could lower the visibility down
to 1SM at times at Crossville through 14z before mixing out. MVFR
fog possible at Clarksville through 14z.
Am expecting scattered thunderstorms again today as air mass
remains moist but not much in the way of a trigger other than
afternoon heating. Will forecast vicinity thunderstorms basically
for the afternoon and early evening hours with some fog developing
overnight with ifr conditions possible at Crossville with mvfr at
Clarksville and Nashville. Areas that get rain today are more
likely to see fog in the late night.
Heat Advisory until 8 PM CDT this evening FOR Bedford-Cannon-