418 
fxus64 kjan 052000 
afdjan 


Area forecast discussion 
National Weather Service Jackson MS 
300 PM CDT Sat Jul 5 2008 


Discussion...tonight through Sunday night...convection continues to 
fire this afternoon and move east southeast across portions of the 
forecast area. Most of the activity is located across 
northwest...north central...and east central Mississippi where a 
moisture axis exists and convection is developing along it. Some of 
this activity will linger into the evening hours...especially across 
my northern zones where a good bit of convection continues firing 
upstream and is being aided by more than just diurnal heating. 
Elsewhere though...as temperatures begin to fall off after 
sunset...look for most of this activity to begin to slowly diminish. 


For tonight...a pretty good shortwave looks to dive into the region 
while a decent upper level jet...60-70 knots...positions itself to 
my west and lining the region up in its left front quadrant. With 
all of this in place...I don't think rainfall chances will 
necessarily fall off everywhere through the evening and overnight 
hours. With all the above in place...look for the disturbance to 
traverse the boundary currently over the area early Sunday morning. 
This will result in showers and thunderstorms again breaking out 
over mainly northern portions of the forecast area early Sunday 
morning. 


Convection should again be ongoing into the afternoon hours 
Sunday...with the better rain chances existing in the east where the 
boundary remains and the upper level disturbance will be exiting the 
area. Then by Sunday evening...look for convection to really begin 
to come to a halt as all of the dynamics and features shift off to 
the east. This on top of the loss of daytime heating. 


With the warm moist and unstable airmass remaining in place over the 
region...coupled with the presence of the upper level 
disturbance...boundary...and the upper jet energy...i'll go ahead 
and keep the mention of at least isolated strong to severe in the 
severe weather potential statement for tonight and into Sunday. However...given how things 
transpire overnight tonight with the disturbance moving across the 
region...it could really work over the airmass and limit activity 
and intensity Sunday afternoon. 


Monday through Friday... not a whole lot of changes in the models 
past Sunday as things begin to settle back down into the typical 
Summer time pattern. High pressure to the east builds into 
the area keeping hot/muggy conditions over the area with mainly 
isolated diurnal showers and thunderstorms expected. As a 
result...the previous long term discussion follows. /19/ 


Monday through Friday...westward extension of the Bermuda high will 
be in control of the weather over the arklamiss region as we go 
through the upcoming work week. Typical early July 
conditions...hot/muggy with isolated/ scattered diurnal thunderstorms...are 
expected. While middle/upper level flow will be very weak...prevailing 
low-level flow should be from the south...and this could promote 
greater chances for convection in spite of subsidence aloft. GFS 
ensemble MOS suggests mex guidance probability of precipitation are a little too low...but 
will refrain from raising probability of precipitation given that both the GFS and European model (ecmwf) 
indicate a strong presence of the subtropical ridge which could 
greatly limit storm organization potential and subsequent coverage. 
Temperatures will be a little above early July average...nothing 
exceptional. /Ec/ 


&& 


Aviation...clusters of showers and storms continue moving across 
the north and east portions of the forecast area. A very moist airmass is 
in place and this activity is expected to persist into early evening 
hours. There will likely be a break through a good chunk of the 
evening...but the evolving flow is supportive of storms to develop 
after say 08-09z and linger into much of Sun morning with new 
development during the day. 


For the most part...IFR/MVFR conditions can be expected in and 
around convection. Areas that get rain today and can clear a bit 
this evening...will likely see some MVFR visible restrictions after 
05-06z. More storm development is expected after 08-09z and timing 
that will be the focus toward the latter portion of the valid 
forecast. /Cme/ 


&& 


Preliminary point temps/pops... 
Jackson 71 92 71 91 / 43 26 14 17 
Meridian 69 89 69 90 / 58 37 31 28 
Vicksburg 71 94 73 93 / 31 18 7 12 
Hattiesburg 69 92 71 91 / 42 29 22 34 
Natchez 70 92 72 91 / 16 14 10 21 
Greenville 72 91 72 93 / 57 22 4 12 
Greenwood 71 89 73 92 / 63 28 10 12 


&& 


Jan watches/warnings/advisories... 
MS...none. 
La...none. 
Arkansas...none. 
&& 


$$ 


19/cme