168 
fxus64 kmrx 181859 
afdmrx 


Area forecast discussion 
National Weather Service Morristown Tennessee 
259 PM EDT Friday Jul 18 2008 


Short term (tonight and saturday)... 
there will be little change in the overall pattern in the next 24 
hours...so will basically follow persistence. MOS guidance 
indicates some fog around the area tonight...however the model 
dewpoints are running too high this afternoon...so their depiction 
of fog may be overdone as well. A strong midlevel capping 
inversion will again prevent deep convection from developing 
tomorrow afternoon. 850 mb temperatures and 1000-850 mb thickness 
increase tomorrow...so expect highs a few degrees higher than 
today. But MOS has been running a bit warm...so leaned toward the 
slightly cooler met guidance. 


Long term...(saturday night through friday)... 
high pressure ridge at the surface and aloft continues Saturday 
night and weak low pressure off the coast of the Carolinas will be 
far enough away for dry conditions across the forecast area 
Saturday night. Sunday Ridge starts to shift southwest and weak 
shortwave energy moves into Tennessee Valley from the northwest ahead of surface 
low and nearly stationary cold front moving across the southern 
Great Lakes. Heating and instability enough to set off isolated 
showers and thunderstorms during the middle afternoon to early 
evening. Monday there should be a better chance all day as front 
moves into Ohio Valley and shortwave energy spreads out ahead of 
front. For the rest of the week models generally keep front across 
or just south of forecast area so have chance showers and 
thunderstorms through Friday. GFS keeps ridge stronger over 
forecast area Monday and Tuesday and front farther north but European model (ecmwf) 
brings short wave energy and front into Tennessee by Tuesday with drier 
air across the NE section briefly Wednesday. Followed the preffered 
European model (ecmwf). Temperatures will be near 90 to lower 90s Sunday through 
Tuesday and then cooler with more clouds and rain chances as upper 
trough moves into NE part of the country. 


&& 


Preliminary point temps/pops... 
Chattanooga Airport, Tennessee 67 94 68 91 69 / 0 0 10 20 20 
Knoxville McGhee Tyson Airport, Tennessee 65 92 66 91 69 / 0 0 10 20 20 
Oak Ridge, Tennessee 64 92 67 90 69 / 0 0 10 20 20 
Tri Cities Airport, Tennessee 57 91 59 90 63 / 0 0 10 20 20 


&& 


Mrx watches/warnings/advisories... 
NC...none. 
Tennessee...none. 
Virginia...none. 
&& 


$$ 


Dgs/dew point