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fxus64 khun 192315 aaa 
afdhun 


Area forecast discussion...updated 
National Weather Service Huntsville Alabama 
615 PM CDT Sat Jul 19 2008 


Update...for 00z tafs/aviation discussion 
&& 


Aviation...continued hazy conditions...as a result of the stagnant 
air pattern...will lead to predom MVFR conditions...mainly for 
reduced visible...at the terminals through the period. 
&& 


Short term...tonight through Tuesday night...hazy and hot 
conditions will continue through the weekend with the ridge in 
place. Most of the area should experience daytime highs well into 
the 90s with some locations approaching 100. Increased temperatures 
slightly for Sunday and especially Monday when the maximum amount of 
heating/waa/subsidence will be in place. Moisture will be increasing 
both Sunday and Monday with southerly flow. With temperatures/dewpoints on 
Monday...will continue to monitor for possible heat advisory if 
trends continue to hold. 


Patchy fog is possible tonight and Sunday night with light 
winds...mostly clear conditions...and increased moisture over the 
region. 


The aforementioned shortwave trough is depicted by European model (ecmwf) as 
deepening into a bowling Ball low over the Great Lakes and Ohio 
River valley by Monday night into Tuesday. This will ride over the 
ridge and amplify the ridge to the northwest. This may lessen the 
heat somewhat with a wind direction change and perhaps a decrease in 
moisture. 


Given the amount of heating and also looking at bufr 
soundings...isolated afternoon/evening T-storms are possible and 
have included that for all of the short-term. However...Monday looks 
to be the prime day for these with the increased heating/moisture 
and steepened lapse rates. 


Long term...Wednesday through Saturday...the extended forecast 
looks better with northwest flow aloft and shortwaves proceeding southeast 
towards the Tennessee Valley. Cloud cover looks to increase somewhat with 
the weak shortwaves depicted by ECMWF/GFS. Timing looks suspect...as 
always...and have left the current chance pop grids in place. One 
thing that is not clear is whether one of the shortwaves actually 
pushes a weak front on Thursday and stalling across the area. If 
this occurs...there may be more precipitation possible. Of course given 
that this is day 6-7...confidence is low. Daytime temperatures will 
generally remain in the 90s with lows in the upper 60s to lower 
70s. 


On another intriguing note...both European model (ecmwf)/GFS are depicting a 
ts/hurricane over the western Gulf by Wednesday. This would be what 
these two models depict as the progression of the current tropical 
wave over the north central Caribbean Sea. 
&& 


Preliminary point temps/pops... 
Huntsville 68 96 72 97 71 / 10 20 10 20 10 
Shoals 68 97 71 97 70 / 10 20 10 20 10 
Cullman 67 95 71 95 70 / 10 20 10 20 10 
Fayetteville 67 94 71 96 68 / 10 20 10 20 10 
Albertville 67 95 72 96 70 / 10 10 10 20 10 
Fort Payne 63 95 69 97 67 / 10 10 10 20 10 
&& 


Hun watches/warnings/advisories... 
Alabama...an air quality alert is in effect for the Tennessee Valley for 
Morgan/Madison counties through Sunday. 
Tennessee...none. 
&& 


$$ 


Aviation: 09 
discussion: 77