331 
fxus64 klix 190945 
afdlix 


Area forecast discussion 
National Weather Service New Orleans la 
445 am CDT Friday Mar 19 2010 


Synopsis...large area of high pressure remains over the 
southeastern states this morning. Clear skies with near calm winds 
over the region have allowed temperatures to dip into the lower 
40s at some locations with 50s over areas south of Lake 
Pontchartrain and at some locations along the Gulf Coast. A few 
areas have developed patchy fog...as dewpoint depressions are 
generally less than 5 degrees. 


Short term... 
this large area of high pressure will move east over the next 48 
hours...with southeast to south winds returning some moisture into 
the region starting tonight. The next weather maker is cranking up 
as a strong area of low pressure and the associated cold front 
move from the Southern Plains states toward Louisiana and 
Mississippi by Saturday morning. Winds will pick up over the 
region by Saturday and continue into Saturday night. Although the 
flow will be mostly southeasterly...moisture will be slow to 
increase until Saturday night. By Saturday night dew points push 
into the middle to upper 50s and the best chance for strong weather 
occurs about 03z to 12z Sunday morning. The overnight period will 
see considerable convection with strong directional and speed 
sheer prognosticated in the wind profiles. Timing this fast-moving front 
will be critical for strong storm development. In the models it 
appears that the better winds/dynamics generally right with the 
front. At the same time...the moisture advection appears to be 
stunted ahead of the system and therefore could be the limiting 
factor for widespread severe convection. There should be enough 
juice for isolated strong storms with winds...and possibly some 
hail...the likely hazards. 


Will make few changes in the temperatures. Models cranking mostly 40s 
tonight after daytime highs in the 60s and 70s. By Saturday 
night...the temperature regime will change with the passage of the 
cold front. Strong...gusty winds will push cold air in and 
temperatures should drop rapidly behind the front. Lows over 
southwest Mississippi will be in the upper 30s and lows will be in 
the 40s over southeastern Louisiana. Ahead of the boundary over 
coastal Mississippi and parts of the South Shore...lows will be in 
the 50s. Sunday's highs will be in the 50s and 60s...as windy 
conditions continue. 


Long term...upper system shifts towards the East Coast Sunday 
night. A ridge of high pressure will develop over the region 
bringing fair conditions before the next upper system rolls out of 
The Rockies Wednesday night. Forecast pattern still suggest that 
strong convection could develop late next week. 


Aviation...overall things remain quiet and at 08z all tafs sites 
were still in VFR. That said there is still the possibility of MVFR 
visbies developing b/T 10z and 13z. Once the sun some out any light 
br/fog out there will quickly burn off. For the rest of the day look 
for VFR conditions to rule the day. As we head into the night and 
mainly overnight hours visbies could become a problem as moisture 
tries to slowly return. /Cab/ 


&& 


Marine...high pressure over the area will slowly work east across 
the northern Gulf today. In addition a surface low will begin to develop in 
western Texas. This will cause onshore to recommence later today. Moderate 
onshore flow will begin to develop overnight Friday and more so 
Saturday in advance of a strong cold front. This cold front will 
move through Saturday evn and on the back side of this front winds 
will quickly veer around to the west-northwest and quickly ramp up. Strong surface 
pressure rises and very strong cold air advection will lead to strong winds with 
and seas rapidly increasing to at least high end scy conditions 
beginning around midnight Sun morning. Frequent gale force gusts 
look possible bordering likely early Sun morning. A gale watch may 
be needed later today for the overnight hours Sat and into the day 
sun. As we move into sun...a tight pressure gradient and persistent 
cold air advection will continue to lead to scy conditions through the day sun and 
even overnight sun. Late Monday morning/midday winds should start to 
relax as high pressure builds back into the Gulf. /Cab/ 


&& 


Preliminary point temps/pops... 
mcb 71 47 70 39 / 0 10 20 80 
btr 72 48 73 42 / 0 10 30 80 
asd 72 48 70 44 / 0 10 20 80 
msy 71 52 72 46 / 0 10 20 70 
gpt 69 51 69 46 / 0 10 20 70 
pql 70 47 70 53 / 0 10 10 70 


&& 


Lix watches/warnings/advisories... 
la...none. 
GM...none. 
MS...none. 
GM...none. 
&& 


$$