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fxus64 khun 240008 
afdhun 


Area forecast discussion 
National Weather Service Huntsville Alabama 
708 PM CDT Wednesday Jul 23 2008 


Update...cold front looks to be along the Alabama/Tennessee border at 7 PM. Skies 
have cleared out/precipitation moved south of the County Warning Area...as drier/more 
stable air begins to move into the County Warning Area. Will update zones to 
remove mention of precipitation and evening wording. Could see some patchy 
fog overnight but with north winds around 5 miles per hour and lower dewpoints 
prognosticated to move across the Tennessee Valley...not expecting widespread/dense 
fog...so will not mention in zones for now. 


Already sent updated grids and will send zones out by 730 PM. 


&& 


Aviation...MVFR conditions may be possible for patchy fog 
between 10z and 14z...otherwise expect VFR conditions for the 
remainder of the taf forecast. 


&& 


Previous discussion... /issued 355 PM CDT Wednesday Jul 23 2008/ 


Mesoscale update... 
several clusters of pulse thunderstorms continue across the hun County warning forecast area 
this afternoon. The good news is that air temperatures are nowhere near what 
they were yesterday /mid-upper 80s vs. Middle-upper 90s/ so low-level 
instability has not been sufficient for the microburst/wind damage 
seen more often yesterday. In terms of radar...enhanced elevated 
cores have been quite fleeting and have been preceded by a jump in 
the NASA-lma flash rates...and only 1-2 storms have displayed any 
interesting velocity signatures. The storms are now congealing into 
a line along and west of the hsv metropolitan area...and this likely 
reflects the surface cold front since dewpoints in middle Tennessee drop quickly 
into the low-middle 60s. 


Storms thus far have not been displaying any trends upward or 
downward...so scattered Special Weather Statement-criteria storms seem likely to continue 
for the next hour or two. 


Discussion...issued 310 PM CDT Wednesday Jul 23 2008... 
analysis wise...a cold front as of 3 PM extended from along the 
MO/Arkansas border to south of Nashville to western Virginia. Earlier pre- 
frontal stratus development south of the front definitely put a 
damper on high temperatures across the Tennessee Valley compared to 
the past few days. Temperatures thus far ranged from 86 at feet Payne to 88 
at Vinemont. Despite the cooler temperatures...lift provided by the 
approach of the cold front...existing instability and plenty of 
moisture has allowed more showers and T-storms to re-develop across 
the area. Some of the storms have been severe with the primary 
threat damaging winds. 


A bigger scale view at 500mb noted upper ridging extending northward 
from West Texas to the northern plains...with a deep low moving over 
southern Quebec. Hurricane Dolly as of this writing was making 
landfall over South Padre Island of deep south Texas. A quick look 
at short and long term guidance suggests that moisture associated 
with Dolly will have no direct affect on the weather locally. 
However...some the moisture from its remains drifting into the 
westerlies could reach this area in a week or so. 


For this evening...a cold front is set to make a move across the 
Tennessee Valley...with more showers and T-storms for the very short 
term into the evening. Scattered convection this evening will end 
from north to south as the cold front moves southward. Clouds also 
should decrease with mostly clear to partly cloudy skies by Thursday 
morning. 


Thursday should be a dry and more comfortable day...with high temperatures 
in near seasonable/average readings around 90. Will continue the dry 
trend for Thursday night by removing isolated convection mention. 
However showers and T-storms return on Friday as a southern flow 
returns with more moisture and instability. Followed the wetter GFS 
solution here...with the NAM and its MOS guidance Friday afternoon 
staying dry. 


More of a Summer type pattern returns for the weekend into the 
middle of next week. Present heat...moisture and available lift 
together will be sufficient to keep some chances for showers and 
T-storms in the forecast. High/low temperatures will average around 
to a tad above seasonable norms. 


&& 


Hun watches/warnings/advisories... 
Alabama...none. 
Tennessee...none. 
&& 


$$ 


Sunset