692 
fxus64 kbmx 211109 
afdbmx 


Area forecast discussion 
National Weather Service Birmingham Alabama 
515 am CST Friday Nov 21 2008 


Update...updated for aviation discussion. 


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Short term...today and tonight. 


Dry cold front currently working its way through the state with 
breezy northerly winds and a few low level clouds. This will 
equate to plenty of cold air advection through the rest of the day 
and a ton of dry air settling across the state. We will really 
struggle with highs today...in fact...have lowered afternoon highs 
a degree of two from earlier forecast packages as newer guidance 
continues to trend down. As the winds relax through the evening 
hours...radiational cooling will take over under clear skies 
leaving US with possibly the coldest temperatures of the season thus far. 
Bundle up! 


17/klaws 




Long term...Saturday through Thursday. 


Cold dome of high pressure will slide off quickly to the east with 
southeast surface winds returning to area Saturday afternoon. This 
will allow temperatures to rebound nicely into middle to upper 50s 
after a cold start to the morning. Warming temperatures and low 
dewpoints will combine to produce low relative humidities Saturday 
afternoon and high fire danger. Fast moving short wave trough will 
pass to the north of Alabama Saturday night. The trough will not 
have any discernible impact on weather. A stronger short wave 
trough will dip into the upper Mississippi River valley region 
Sunday night. Deepening southerly flow on back side of East Coast 
ridge will allow for limited moisture return ahead of advancing 
cold front. GFS model has shown good run to run consistency with 
this system. Surface cold front will push through central Alabama 
Monday afternoon producing scattered showers. There may be enough 
instability across South Alabama for isolated thunderstorms...but 
left thunder out of forecast for now. This is a progressive system 
and rain will move out of area Monday evening. 


Mostly clear conditions Tuesday and Wednesday with temperatures 
near average. A low latitude strong Pacific system will move into 
the southwestern states by middle week. This system will cross The 
Rockies and into the Southern Plains states by end of the week. 
Models typically shift these systems to fast to the east...but did 
introduce small rain chances West Alabama Thursday night. 




58/rose 


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Aviation...12z taf discussion. 


Any leftover clouds are dissipating...leaving clear skies and a 
breezy northerly wind. Winds should gradually relax through the day 
and slowly shift towards the northeast. We should generally return 
to calm winds shortly after sunset. VFR conditions expected through 
the period. 


17/klaws 


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Fire weather... 


Low humidities in the wake of a cold front will create a high fire 
danger across the area for several hours on Saturday. 


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Bmx watches/warnings/advisories...Fire Weather Watch all zones 
Saturday 11 am to 5pm. 


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$$