Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Morristown Tennessee
issued by National Weather Service Nashville Tennessee
242 PM EDT Tuesday Sep 30 2014
Short term...(tonight through thursday)...with upper level ridging
influences in place supporting mostly clear skies and light to calm winds...
another good radiational night is in store for the Tennessee Valley region
with at least patchy fog development near and around bodies of water...
mainly during the 06z-15z time frame. May not be as widespread as
this morning though...with some scattered high level cloudiness expected
to ride over upper level ridging influences. Latest 12z guidance
suggesting morning forecast package overnight lows for tonight
still in line and will lean accordingly. Continuance of upper level
ridging influences Wednesday through Wednesday night will provide for mostly clear skies.
Highs on Wednesday will be in the upper 70s SW Virginia to middle 80s lower Tennessee
Valley region. Lows Wednesday night will range from the middle to upper 50s
SW Virginia to lower 60s lower Tennessee Valley region. Expect a gradual increase
in cloudiness as the day progresses on Thursday as a low pressure system
over S central Canada deepens with a cold front extending southward to a
surface low across the Southern Plains...which is expected to move slowly
eastward. This will continue to put the Tennessee Valley region in a warm air advection pattern
with highs across the area mainly in the low to middle 80s. System might
be a little slower moving in than previously anticipated...and have
tailored weather and expected probability of precipitation accordingly with lows generally spanning
Long term...(friday through tuesday)...looks like the brunt of shower
and scattered thunderstorm activity will occur on Friday as frontal system pushes
across the Tennessee Valley region with temperatures more in the line with
seasonable normal values. Maybe some evening convection across the
Tennessee Valley on Friday night...otherwise expect generally dry northwesterly flow
aloft with surface ridging influences from The Rockies building into
the middle state through the weekend. A weak system looks to approach the
Tennessee River valley on Monday bringing a chance of showers again to the area
with ridging influences again building into the valley by the middle
portion of next week. Temperatures will continue to trend toward seasonable
normal values from the weekend through the first part of next week.
Preliminary point temps/pops...
Chattanooga Airport, Tennessee 59 86 63 85 66 / 0 0 0 10 60
Knoxville McGhee Tyson Airport, Tennessee 57 83 60 85 64 / 0 0 0 10 60
Oak Ridge, Tennessee 56 84 60 84 64 / 0 0 0 10 60
Tri Cities Airport, Tennessee 50 82 52 83 58 / 0 0 0 10 30