465 
fxus64 kmeg 070214 aaa 
afdmeg 


Area forecast discussion...updated 
National Weather Service Memphis Tennessee 
914 PM CDT Monday Oct 6 2008 


Update... 
showers and thunderstorms over central Arkansas continue to edge 
gradually toward the midsouth at midevening. These showers and 
thunderstorms were occurring ahead of an upper low over Kansas. 02z 
surface analysis showed middle to upper 60s dewpoints over the 
southwest half of Arkansas. Over the midsouth...including northeast 
Arkansas... the boundary layer was drier...with dewpoints in the 50s. 


A few peripheral showers have made it into Lawrence and Randolph 
counties at discussion time. Further eastward progress has been 
limited by the dry air. However...expect the low level moisture 
axis to shift gradually east overnight...with the slow eastward 
progress of the main upper level system. 


Have made minor updates to the forecast grids to account for the 
pre midnight showers over northeast Arkansas. Otherwise...no changes at 
this time. 


Pwb 


&& 


Previous discussion... /issued 348 PM CDT Monday Oct 6 2008/ 


Discussion... 


Currently...high pressure remains in control throughout the region 
as another beautiful afternoon is underway across the middle south. 
There is plenty of sunshine with temperatures in the lower to middle 
80s. 


Tonight through Wednesday night...the weather pattern becomes much 
more active this week as a major upper level trough over the 
Southern Plains moves toward the middle south tonight. Expect quiet 
weather to continue through the evening hours and then after 
midnight moisture and lift will rapidly increase across the western 
parts of the middle south in advance of the upper level trough. 
Showers and thunderstorms will develop across Arkansas overnight 
and move into eastern Arkansas after midnight...perhaps spreading 
into parts of west Tennessee and north Mississippi before sunrise. 


Will continue to follow the GFS model for this forecast package. 
It has been fairly consistent over the last few runs. On Tuesday 
the upper trough will move into western parts of the middle south 
during the day as the associated surface low tracks across central 
Missouri. The associated cold front will push across Arkansas 
during the day to near the Mississippi River by Tuesday evening. 
Due to the extensive lift and deep moisture that will be in place 
across the middle south expect widespread showers and thunderstorms 
to spread across the entire middle south during the day. At this 
time the severe threat appears minimal. Expect widespread clouds 
and precipitation to hamper surface based instability across the area. 
The best chance for some stronger storms continues to be across 
east central Arkansas and north Mississippi where some sbcapes may 
reach 1000 j/kg Tuesday afternoon into Tuesday evening. Heavy 
rainfall is also possible with precipitation h20 values near 2 inches. 


The cold front will continue to move across the middle south Tuesday 
night while the upper trough will begin to cut off and move into 
northern parts of the middle south by early Wednesday morning. Expect 
lingering showers and perhaps a few thunderstorms Wednesday 
across mainly the eastern half of the middle south with much cooler 
temperatures. Some places may no reach 70 degrees as the upper 
low moves through on Wednesday. After a few lingering showers 
Wednesday evening across eastern sections precipitation will come to an 
end as the upper low moves into the southeast U.S. 


Thursday through Saturday...weak high pressure will prevail across 
the region with rain free weather. Temperatures will climb back 
into the lower 80s by Friday and Saturday. 


Sunday and Monday...big question Marks this far out. Models are 
all over the place. The 12z GFS has backed way off on the huge 
upper low that was forecast to impact the area during this time 
frame. Now that feature is well of the northwest of the area by 
Monday morning with a front approaching the region. Meanwhile the 
European model (ecmwf) has a large ridge over the area. For now left a 20 probability of precipitation for 
Sunday and Sunday night and chance probability of precipitation for Monday. Confidence is 
very low for this part of the forecast. 


&& 


Preliminary point temps/pops... 
mem 67 77 63 72 / 50 90 80 40 
mkl 60 77 63 69 / 20 90 90 50 
jbr 62 73 59 71 / 70 90 70 30 
tup 61 79 65 73 / 20 90 90 50 


&& 


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


$$