924 
fxus64 klix 182003 
afdlix 


Area forecast discussion 
National Weather Service New Orleans la 
303 PM CDT Thursday Mar 18 2010 


Synopsis... 
high pressure centered over northeast Texas at early afternoon. 
Upper low over Georgia has a cold pocket of air extending westward 
back into southern Mississippi. The cold pocket has allowed the 
development of cold air stratocumulus across much of the area. 
This has limited the heating effect of the sun slightly...with 
temperatures mainly remaining in the lower and middle 60s. 35 
&& 


Short term... 
high pressure will move eastward over the next 48 hours with the 
cold front into East Texas by Saturday morning. Moisture will be 
slow to increase until then as return flow will be rather weak. 
Saturday...southerly flow a little better...and we get dew points 
into the middle to upper 50s. While this will be sufficient for 
precipitation Saturday night...model soundings are not very 
conducive for severe weather. Front moves through rapidly Saturday 
night. Continuing the small probability of precipitation for Saturday as in previous 
forecast...with likely probability of precipitation across the area on Saturday night. All 
precipitation should end by sunrise on Sunday. 


Overall...guidance temperatures in the short term are in the neighborhood 
of the previous forecast. Chilly tonight...about 5-10 degrees 
below normal...then close to normal for Friday until frontal 
passage Saturday night. Frontal passage will bring a rapid cooloff 
with a 20 degree drop in a few hours likely. Sunday highs will 
struggle to reach the upper 50s...and that will take sunshine. 35 
&& 


Long term... 
upper system moves east of the area Sunday night...with ridging 
controlling the weather until the next upper system rolls out of 
The Rockies Wednesday night. Medium range models still have some 
discrepancies as to the timing of that system...and for now...will 
keep mention of precipitation in for Thursday. If forecast surface 
pattern verifies...still a potential severe weather maker. Have 
backed off on the warming Monday and Tuesday from previous 
forecasts...but Wednesday and Thursday should be close to normal. 35 
&& 


Aviation... 
cold air advection induced high based cumulus deck at 5-6kft should 
erode with sunset for VFR ceiling and visibility unlimited conditions overnight. Some patchy 
radiational fog possible mainly at kmcb after 09z then VFR ceiling and visibility OK 
conditions for much of Friday as flow becomes slowly onshore 
oriented in response to approaching system for Saturday. 24/rr 
&& 


Marine... 
no particular concerns in the short-term as flow veers easterly to 
southeasterly through Friday then moderate onshore flow for Friday 
night into Saturday in advance of developing Spring storm in the 
High Plains. Associated cold front should move through the north 
Gulf waters Saturday night with dry air momentum Transfer and cold 
air advection likely to onset near gale or minimal gale conditions 
for a period of time Sunday. At this time...it seems certain for 
small craft conditions but gales may be limited to frequent gusts in 
the 34-40kt range. Seas expected to build to around 9 feet Sunday. 
As high pressure builds over north Gulf...winds and seas should 
settle to light levels for first half of next week. 24/rr 
&& 


Preliminary point temps/pops... 
mcb 40 71 47 70 / 0 0 10 30 
btr 43 72 48 73 / 0 0 10 30 
asd 41 72 48 70 / 0 0 10 20 
msy 48 71 52 72 / 0 0 10 20 
gpt 43 69 51 69 / 0 0 10 20 
pql 41 70 47 70 / 0 0 10 20 


&& 


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


$$