280 
fxus64 kcrp 231154 
afdcrp 


Area forecast discussion 
National Weather Service Corpus Christi Texas 
554 am CST Monday Nov 23 2009 


Discussion...see aviation section. 


&& 


Aviation...areas of dense fog will lift by middle morning...leading 
to VFR conditions through the afternoon. Increasing moisture will 
result in ceilings developing and lowering to MVFR category through 
tonight. Patchy fog is also expected tonight however the broken 
stratus deck will inhibit radiational cooling and keep fog from 
becoming dense for most locations. Thus vsby's are expected to 
also remain generally MVFR to upper IFR categories. A cold front 
is expected to begin filtering into S Texas through the early morning 
hours with winds backing to the east and NE. Rain chances will also 
be on the increase into Tuesday morning...however tsra's are expected 
mainly after 12z Tuesday as well as the stronger north winds. 


&& 


Previous discussion... /issued 408 am CST Monday Nov 23 2009/ 


Short term (today through tuesday)...fog/low stratus is forming 
across S Texas per satellite imagery and observations. Am expecting 
this trend to continue toward sunrise with many areas experiencing 
dense fog this morning. The fog is expected to lift by middle morning. 
A southeast flow will increase to 10 to 20 miles per hour and usher in Gulf moisture 
through the day...leading to a slightly warmer day and increasing 
clouds. Rain chances will increase tonight mainly due to increasing low 
level convergence as upper level dynamics will be lacking. A cold 
front is forecasted to move into S Texas by early Tuesday morning...however 
models have been inconsistent with timing and strength. The NAM is 
slower and weaker while the GFS is faster with a stronger northerly wind 
in its wake. Have leaned toward the faster GFS solution and am showing 
winds backing to the NE between 06z-12z then strengthening through 
18z as high pressure builds across S Texas. There will also be the 
potential for fog ahead of the boundary tonight with the increasing 
convergence...dewpoints and light winds. Although clouds should 
inhibit radiational cooling...therefore am not expecting dense fog 
for tonight. The GFS shows increasing cape and decreasing cin ahead of 
the boundary and with the convergence and sufficient moisture...should 
produce scattered to num shra's/tsra's for Tuesday. The higher probability of precipitation shift S as 
the boundary moves S. Thunderstorms and rain potential decreases behind the front with the 
loss of cape with mainly residual shra's for a few hours behind the 
front. Given the lack of upper support with both the subtropical jet 
and polar jet far removed from S Texas...am not expecting any severe weather at 
this time. 


Marine...a weak to moderate onshore can be expected today ahead of a 
cold front that is expected to move across the coastal waters 
through early Tuesday morning. A strong offshore flow will develop in 
its wake with Small Craft Advisory conditions likely by Tuesday afternoon. Scattered to numerous 
showers and thunderstorms are expected ahead and along the cold 
front then decreasing behind the front. 


Long term (tuesday night through sunday)...a dry and cool airmass 
will prevail through Friday as a persistent surface ridge axis continues to 
build into the County Warning Area. Temperatures will remain below normal...especially the 
overnight lows due to the excellent radiational conditions. 
Moisture will begin moving into the County Warning Area by late Friday as the middle/upper ridge 
axis weakens and pushes east of the County Warning Area. Isentropic lift and 
increasing moisture advection over the weekend in advance of a 
deepening middle/upper trough axis across The Rockies will lead to the 
development of isolated precipitation. Will show a gradual warming trend 
beginning on Friday. However...the thickening cloud cover over the 
weekend will tend to hamper the overall warming trend. 


&& 


Preliminary point temps/pops... 
Corpus Christi 78 64 72 49 69 / 10 20 70 10 0 
Victoria 77 58 67 42 67 / 10 20 60 10 0 
Laredo 82 64 70 47 73 / 10 20 50 10 0 
Alice 79 61 71 47 71 / 10 20 60 10 0 
Rockport 74 66 73 50 68 / 10 20 70 10 0 
Cotulla 76 61 67 37 71 / 10 20 40 10 0 
Kingsville 79 64 72 47 70 / 10 20 70 10 0 
Navy corpus 75 67 74 55 68 / 10 30 70 10 0 


&& 


Crp watches/warnings/advisories... 
Texas...dense fog advisory until 9 am CST this morning for the following 
zones: Bee...Calhoun...Duval...Goliad...Jim Wells...La 
Salle...Live Oak...McMullen...Refugio...Victoria. 


GM...none. 


&& 


$$ 


Te/81...short term 
mb/80...long term