123 
fxus64 kmrx 211845 
afdmrx 


Area forecast discussion 
National Weather Service Morristown Tennessee 
245 PM EDT Thursday Aug 21 2008 


Short term (tonight and friday)... 
high pressure over New England will extend southwest over the 
southern appalaichian region...while Kay begins a slow westward 
motion. Forecast soundings remain quite stable and dry through 
Friday...so no precipitation is expected. Some high clouds associated with 
blow off from Fay may move aross southern sections tonight and 
tomorrow. Downslope flow on frdiay should provide additional 
drying and warming...and leaned toward the warmer GFS MOS guidance 
again for highs on Friday. Winds will pick up a little more 
tomorrow as Fay gets a little closer...between 10-15 miles per hour in the 
southern sections of the County Warning Area Friday afternoon. 


Long term (friday night through thursday)... 
biggest question for extended forecast is when will remnants of 
Fay affect the forecast area. European model (ecmwf) and GFS models show Fays 
remnants to affect the eastern Tennessee Valley mainly Tuesday and 
Wednesday with possible heavy rainfall. Before that time moisture 
will gradually increase Friday night and Saturday. Then Saturday 
night through Sunday night showers may develop becoming more likely 
Monday night into Wednesday. As the storm moves west across the 
Florida Panhandle rain along the extreme northern edge could spread 
into the southern valley and SW NC Saturday night. Then Sunday 
through Monday with increased moisture from southerly flow and 
instability and an approaching front that is expected to be just 
north of the forecast area there will be slight chances of showers 
and possibly a thunderstorm. 


Model soundings continue to indicate a stable airmass Saturday but 
the sounding becomes increasingly moist Sunday and Monday. With 
abundant middle and high level moisture the airmass will only be 
slightly unstable. The models bring the weak cold front into the 
forecast area Tuesday with Fays remnants still over MS and Alabama and 
then keep it the front or near the forecast area through Thursday. 
Will keep chance probability of precipitation in through Thursday. Temperatures will be 
influenced by the increase of moisture but because of the dry ground 
should still see highs near 90 south Saturday through Monday. Lows 
will remain steady over the weekend in the upper 50s to lower 60s 
northeast where airmass will be drier to the middle 60s to near 70 
south. 


&& 


Preliminary point temps/pops... 
Chattanooga Airport, Tennessee 68 88 69 89 68 / 0 10 10 10 20 
Knoxville McGhee Tyson Airport, Tennessee 66 90 66 89 66 / 0 0 10 10 10 
Oak Ridge, Tennessee 65 90 66 90 66 / 0 0 10 10 10 
Tri Cities Airport, Tennessee 61 87 59 88 60 / 0 0 10 10 10 


&& 


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


$$ 


Dgs/dew point