545 
fxus64 kmeg 212124 
afdmeg 


Area forecast discussion 
National Weather Service Memphis Tennessee 
324 PM CST Sat Nov 21 2009 


Discussion...surface analysis this afternoon places an area of 
low pressure off the Louisiana coast while aloft an upper level 
low was located over East Texas. Skies have been mostly sunny with 
a gradual increase in clouds across north Mississippi this 
afternoon. Temperatures as of 3 PM CST are in the lower to middle 
60s across many locations. Rain chances tonight through Tuesday 
are the main challenges in this afternoon/S forecast package. 


Short term...(tonight through tuesday)...WRF/GFS short term 
models indicate weak surface/upper level low will continue to move 
east/northeast over the next 24 hours across Mississippi and 
Alabama. For the past few hours regional WSR-88D radar trends have 
shown an increase in returns over central/south Mississippi as 
isentropic ascent increases across the area. Metar observations have 
shown hourly rainfall amounts averaging around a hundredth at best 
thus far and agrees well thus far with light amounts advertised by short 
term model soundings. Rain chances will be limited to areas south 
of I-40 tonight and Sunday where best isentropic ascent /lift/ 
will be located. Any lingering rain Sunday will depart the middle 
south by late afternoon/early evening. 


Another cold front is expected to move through the lower 
Mississippi Valley Monday night into Tuesday morning. Raised probability of precipitation 
up to chance during this time frame...but expect overall rain 
amounts to be light. 


Long term...(tuesday night through saturday)...12z GFS/European model (ecmwf) in 
decent agreement with another upper level trough settling into the 
eastern United States by Thanksgiving into Friday. Rain free 
weather is expected during this period with near normal 
temperatures for November dropping to below normal values for 
late next week. 


Cjc 
&& 


Aviation... 
18z tafs 


At kmem...kmkl...and kjbr...VFR conditions are expected through 
18z Sunday with east winds. Ceilings will develop and slowly 
lower. -Ra may get close to kmem and kmkl after 11z...but think 
most -ra will stay south and east of these sites...so did not 
mention in tafs. MVFR ceilings may get close to kmem and kmkl 
after 16z...but chose to keep out of taf for now thinking these 
lower ceilings will move into these sites after 18z. 


At ktup...VFR conditions are expected through 06z...then 
deteriorating conditions can be expected...especially 06-15z as 
-ra moves into this site. MVFR conditions will develop 07-10z. IFR 
conditions are possible anytime after 09z...but did not mention in 
tafs at this time with low confidence of occurrence. 


Mbs 


&& 


Preliminary point temps/pops... 
mem 48 62 46 62 / 20 10 10 10 
mkl 44 60 45 60 / 10 30 20 10 
jbr 44 61 44 62 / 10 10 10 10 
tup 46 56 46 63 / 70 40 20 10 


&& 


Meg watches/warnings/advisories... 
Arkansas...none. 
MO...none. 
MS...none. 
Tennessee...none. 
&& 


$$