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fxus64 kbmx 151140 
afdbmx 


Area forecast discussion 
National Weather Service Birmingham Alabama 
640 am CDT Monday Mar 15 2010 


Update... 


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Discussion... 


The big upper level low that plagued our area over the weekend is 
forecast to slowly fill and drift eastward over the next couple of 
days. There's still a few spots of drizzle or sprinkles associated 
with this feature around early this morning. But I think those 
should be gone by the time the sun comes up. The cloud will have a 
harder time leaving...however. 


Just when we get rid of one upper level system...another drops in 
from the northwest Tuesday night into Wednesday and Thursday. Here 
the forecast gets tricky again. Most models (including the NAM and 
gfs) bring only spotty precipitation and lower overall moisture levels. 
The European model (ecmwf)...however...takes a bullseye of moisture right over 
central Alabama. While the European model seems to be the 
outlier...I really am hesitant to totally discount it. If the Euro 
verifies...the Wednesday may end up being much like Saturday 
was...with fairly widespread showers dropping mainly light rain. 
All other signs point to less rain coverage (and less quantitative precipitation forecast as a 
result)...so will keep the probability of precipitation relatively low for now. 


That system exits the area by Friday...which should be our one 
decent shot at considerable sunshine this upcoming week. The fast 
upper flow brings the next shortwave trough in here late Saturday. 
The long range models are still hashing out the details on this 
system...but a cold frontal passage some time late Saturday or 
Sunday is probably. There doesn't seem to be enough time for 
return flow to become established enough to boost low level 
moisture to the Point of substantially increasing instability. So 
while I do think that synoptic level forcing will be enough to help 
a few thunderstorms develop...it does not appear the threat of 
strong or severe storms is anything beyond marginal at this point. 


/61/ 


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Aviation...12z taf discussion. 


A few isolated areas of drizzle across the northeast as the upper 
level low spinning off the East Coast slowly moves away from the 
area. Went ahead and removed vcsh as impacts from these showers will 
be minimal. Overcast skies will hover around MVFR ceilings this 
morning...before rising the afternoon to around 3500 to 4000 feet. 


Models tend to underestimate the staying power of low level cloud 
decks in northwesterly flow. Will maintain overcast to broken MVFR decks 
through the 6z period...before giving way to VFR conditions. 


16 


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Bmx watches/warnings/advisories... 
none. 


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$$