Scientific Forecaster Discussion

NWS Discussion
			
				

Area forecast discussion...updated 
National Weather Service Jackson MS 
853 PM CDT Tuesday may 21 2013 


Update...focus for the rest of this evening and some of the 
overnight will be with strong and severe storms moving through a 
good portion of the forecast area. A large line of storms is just 
about to enter the northwest part of the County Warning Area and expectations are for this 
to steadily push east/southeast into the central portion of the County Warning Area before 
showing a decreasing trend. Driving this line is a compact upper 
disturbance which is over southern OK and a large composite cold 
pool (outflow boundary) which has cause quite a bit of wind damage 
over NE Texas/northwest la/SW Arkansas. Over the past hour or two...the outflow 
boundary has become better balanced with the convection and this 
should prove to support a damaging wind threat across the western 
half of the County Warning Area before it may run out of steam. Instability is not 
great (1500 j/kg mlcape)...but system dynamics look to support severe 
storms this evening and a portion of the overnight. As for 
timing...looks like the line could be within the Natchez trace 
corridor between 1130 PM and 130 am...then diminishing east of that 
after 1-2 am. 


As for hazards...damaging winds will be the primary focus with a 
small threat for small hail. The earlier threat for a few tornadoes 
has decreased due to 0-3km shear vectors oriented to the NE and the 
linear complex propagating to the E/se. A severe ts watch may be issued 
for a portion of the for some of the night period. /Cme/ 


&& 


Aviation...timing the restrictions with the storms will be the 
focus tonight. Outside that...VFR conditions look to prevail with 
some potential for a period of MVFR ceilings between 11-14z Wednesday 
morning. Not sure if there will be much precipitation development on Wednesday 
due to what impacts to the atmosphere happen from the storm complex 
tonight...thus will not mention precipitation risk for the afternoon 
timeframe. /Cme/ 


&& 


Preliminary point temps/pops... 
Jackson 69 85 61 90 / 79 48 9 6 
Meridian 65 85 60 90 / 41 43 22 5 
Vicksburg 70 86 59 89 / 100 43 5 5 
Hattiesburg 68 87 67 90 / 31 40 17 10 
Natchez 70 86 64 88 / 95 49 10 15 
Greenville 68 85 61 88 / 100 34 3 3 
Greenwood 69 84 58 87 / 100 43 4 5 


&& 


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


$$ 


Cme/