107 
fxus64 kjan 211946 
afdjan 


Area forecast discussion 
National Weather Service Jackson MS 
246 PM CDT Thursday Aug 21 2008 


Short term...water vapor imagery this afternoon shows the upper low 
lifting north into the middle Mississippi Valley region. Tropical Storm 
Fay is also spinning over the northeast coast of Florida. Radar imagery 
shows showers and thunderstorms have developed over portions of the 
arklamiss region. This is expected to continue into the evening 
hours. Activity is expected to die down after sunset. With the 
upper low drifting to the north...the area will be losing any 
forcing mechanism. So as heating dies down activity should begin to 
die down as well. This will leave for a quiet night with less cloud 
cover over the area than we have seen in previous nights. The upper 
trough will continue to lift north for Friday and into Saturday. 
This will allow for decreasing rain chances over the County warning forecast area for the 
next couple of days. There will still be plenty of moisture 
lingering over the area...which will still allow for some scattered 
showers and thunderstorms to develop...mainly over the northwestern 
portions of the County warning forecast area in the afternoons and evenings. Overall through 
the next couple of days do not anticipate much of a risk for 
strong/severe storms. Can not rule out the possibility of one or 
two storms to become strong each afternoon...but the risk should not 
be high enough to mention in the afternoon severe weather potential statement. With such a moist 
airmass in place over the region there will continue to be the 
possibility for heavy rainfall with any thunderstorms that 
develop. 


High temperatures on Friday should be a little warmer than we have 
seen earlier this week. With the upper low lifting north a 
bit...there will be less cloud cover to keep temperatures down. This 
will especially be true over the eastern half of the County warning forecast area. 
Temperatures on Friday should be able to reach the lower 90s over 
most of the area. Low temperatures should typically be in the lower 
70s over the next couple of nights. For Saturday and Sunday the 
eastern half of the County warning forecast area should begin to see increased cloud cover 
and possibly showers and thunderstorms moving into the region as the 
outskirts of Fay reaches this area. This should limit temperatures 
from rising too much those afternoons...especially on Sunday. 
Overall have remained with gui through the next few days for 
temperatures. 


The big story for the forecast will be what happens with Tropical 
Storm Fay. The latest forecast track from the hurricane center 
brings Fay skirting across the Florida Panhandle coast and into 
southeastern Mississippi as a depression. Obviously if this track 
is shifted at all over the Gulf things could be a little different 
regarding the strength. But regardless...Fay could present a heavy 
rain potential for at least southeastern counties for the late 
weekend into early next week time frame. /14/ 


Long term...by Sunday morning there is considerable difference in 
the models with the position and strength of the center of Fay. Both 
GFS and European model (ecmwf) begin to pivot the remnants of Fay back to the east 
northeast from southern Mississippi on Monday. The European model (ecmwf) is faster 
and farther north over Alabama Tuesday than the GFS but...either 
scenario would result in drier air back over our County warning forecast area from the west 
by Wednesday. The main concern with Fay this morning for our area is 
the potential rainfall over our southeast. Considering the moist 
soils already over the area flash flood watches may be needed in the 
south by this weekend. /22/ 




&& 


Aviation...some scattered to broken middle to high ceilings was 
observed across the region. VFR conditions are expected to prevail 
through much of the day. Scattered showers and thunderstorms will 
again be possible for much of the region this afternoon and into the 
early evening hours...especially at sites located along and west of 
Interstate 55...kjan...kglh...and kgwo. Ceilings and visibilities 
will briefly be reduced to MVFR/IFR flight categories at sites where 
convection is observed. Some patchy fog will be possible at most 
locations on Friday morning...which could briefly lead to MVFR 
visibilities at most sites...except at hbg where some IFR ceilings 
and visibilities is expected after 09z. Any fog that develops in the 
morning...should dissipate by 14z...which will bring VFR conditions 
area wide. 




&& 


Preliminary point temps/pops... 
Jackson 70 91 71 88 / 23 34 30 56 
Meridian 70 90 70 86 / 21 18 34 62 
Vicksburg 71 91 71 89 / 23 44 24 51 
Hattiesburg 71 93 72 88 / 22 27 25 49 
Natchez 71 90 70 88 / 24 41 22 52 
Greenville 70 90 70 89 / 31 51 34 50 
Greenwood 70 90 70 89 / 31 44 40 50 


&& 


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


$$ 


14/17/22