496 
fxus64 kjan 070217 aaa 
afdjan 


Area forecast discussion...updated 
National Weather Service Jackson MS 
917 PM CDT Monday Oct 6 2008 


Update...Gulf air mass surging through southeastern MS showing 2.1 inch 
precipitable waters  on 00z lix radiosonde observation and this juice working northward at 15-20kts through 
eastern and central MS. Models underestimating the quality of air by at 
least 0.5 inches currently. As a result...will boost probability of precipitation in eastern MS 
while keeping 40 percent over a wide area for the rest of tonight 
with tropical rain showers possible at any time. Minor changes to hourly temperatures 
as 70f dewpoints also lifting northward to keep overnight lows quite mild. 


Otherwise...frontal zone still on schedule to cross the County warning forecast area from 
about midday Tuesday through early Wednesday. Quantitative precipitation forecast amounts of 1-2 
inches should be common however sometime these October systems have a 
way of sneaking through as underperformers. Best risk for strong 
storms with wind gusts/hail Tuesday afternoon appears to be for northwestern 
third of County warning forecast area. We shall see./40/ 


Portions of previous discussion follows: the cold front is 
expected to reach the Mississippi River by Tuesday afternoon. The 
front is posed to move east out of the County warning forecast area by Wednesday morning 
with lingering precipitation leaving the area by Wednesday afternoon. 
Moisture has begun to advect into the forecast area today with precipitable waters  
increasing to around 1.5 inches by this evening. Showers and 
thunderstorms are expected to increase ahead of this front this 
afternoon...and spread east across the remainder of the forecast 
area tonight. Lapse rates will be rather marginal on Tuesday. But 
there will be decent flow over the County warning forecast area. As heating progresses in 
the afternoon there will be enough instability to possibly see a few 
strong storms develop. This will continue to be mentioned in the 
afternoon severe weather potential statement. Overall the best energy will lift to the northeast 
of the County warning forecast area so do not anticipate much more than a few strong 
storms. 


Drier and cooler air is expected to move into the area behind the 
front. By Wednesday evening the forecast should be dry through the 
end of the work week. Have pretty much remained close to mav gui for 
temperatures through the short term. Low temperatures tonight will 
be a little warmer with middle 60s expected as cloud cover and rain 
chances will be increasing. High temperatures on Tuesday will be a 
little cooler with the clouds and rain remaining. The area will 
start seeing cooler temperatures move in behind the front with lows 
falling to the middle 50s by Wednesday night and highs on Wednesday 
only reaching the upper 70s. /14/ 


&& 


Aviation...VFR conditions with areas of sky clear will give way as 
moisture continues to increase from the south overnight. A layer of 
stratus between 1200-2000ft is expected to develop from the south by 
08-10z and last through Tuesday. MVFR/IFR visibility can also be expected 
again tonight at most sites as dewpoints rise slowly with greatest 
chance for IFR conditions in the southeast again. More widespread 
coverage of showers and thunderstorms are expected by midday Tuesday 
through the evening ahead of a cold front that crosses the MS river 
in about 24 hours from 08/00-04z./40/ 


&& 


Preliminary point temps/pops... 
Jackson 66 81 61 75 / 40 80 67 15 
Meridian 65 79 58 77 / 38 82 84 20 
Vicksburg 67 82 60 78 / 53 74 50 8 
Hattiesburg 68 81 62 77 / 42 75 55 20 
Natchez 67 82 58 76 / 56 70 45 9 
Greenville 66 79 59 79 / 53 78 49 9 
Greenwood 64 80 60 75 / 32 83 66 15 


&& 


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


$$