596 
fxus64 kmob 220547 aaa 
afdmob 


Area forecast discussion...mesoscale update 
National Weather Service Mobile Alabama 
1145 PM CST Sat Nov 21 2009 


Aviation update...surface low pressure system will move east across 
the coast of southwest Alabama and northwest Florida. As the low 
tracks east...ceilings will remain at IFR/MVFR levels through Sunday. 
Visibilities reduced to IFR/MVFR levels in rain overnight...and due to fog 
on Sunday. /22 


Marine update...a low pressure area just off the southeast Louisiana 
coast will move east...crossing over the marine area by late 
tonight. Strong easterly winds over the marine area are expected to 
increase further...and then shift to the southwest late tonight. 
Sustained speeds of 20 to 25 knots with numerous gusts to near gale 
force will continue into early Sunday morning. Offshore wave heights 
will build to around 7 feet...with rough to very rough conditions on 
bays and coastal waterways.Offshore conditions will improve Sunday 
afternoon as the low pressure area moves further east...followed by 
diminishing winds subsiding seas. In the wake of a strong frontal 
passage late Tuesday...north to northwest winds are forecast to 
increase and seas will build Wednesday and Thursday. /22 


..previous discussion... 


Short term...(tonight through Monday night)occluded surface low 
about 100 miles south southeast of Lake Charles was tracking east to 
east North East and should remain just south of the Alabama coast 
through Sunday before weakening and drifting off to the north. Large 
envelope of mostly light to moderate rain north and northeast of the 
low will move across the area from this afternoon through the 
overnight. A few elevated...isolated thunderstorms possible later 
tonight as the low nears...more likely along the coast. Helicity 
values are quite high but will almost no cape...not expecting any 
strong storms unless the warm sector can manage to move onshore 
before the low passes. If this happens...some stronger storms 
possible mainly on the Panhandle coast late tonight. During the day 
Sunday the low will weaken as the upper support lifts out to the 
north and northeast and some light rain will linger over most of the 
area into the afternoon...possibly early evening over the northeast 
as the colder air aloft moves away. Will leave some clouds through 
the day Monday as low level cloudiness wraps around the departing 
surface low. High about normal for this time of year with slightly 
warmer overnight lows due to cloudiness. /11 


Long term...(tuesday through saturday)after what should be a sunny 
day Tuesday with temperatures in the low to middle 70s...another 
surface trough will move across the area Tuesday night. No rain in 
forecast at this time but will be a band of cloudiness moving east 
across the area Wednesday as high pressure rebuilds from the west. 
Upper low with this system is across the lower Great Lakes so the 
coldest air will be well north of the region but lows the last half 
of the week expected to be in the lower 40s to the upper 30s...new 
guidance was a bit lower but will wait a cycle before biting. /11 


&& 


Fire weather...rain across the area late afternoon into Sunday 
morning. Heaviest rain expected to be along coastal areas. Winds 
generally northeast to east...may see some southeasterly winds along 
the Panhandle coast late tonight. Somewhat drier air by Sunday 
afternoon with still drier air on Monday but not expecting red flag 
conditions behind this system. /11 


&& 


Preliminary point temps/pops... 
Mobile 55 67 50 68 / 80 30 10 10 
Pensacola 58 68 53 67 / 90 40 10 10 
Destin 61 70 58 68 / 90 40 10 10 
Evergreen 52 65 47 67 / 90 60 20 10 
Waynesboro 52 62 47 67 / 90 40 10 10 
Camden 52 61 47 65 / 80 60 20 10 
Crestview 55 70 50 70 / 90 50 20 10 


&& 


Mob watches/warnings/advisories... 
Alabama...none. 
Florida...none. 
MS...none. 
GM...none. 
&& 


$$