283 
fxus64 kcrp 211046 
afdcrp 


Area forecast discussion 
National Weather Service Corpus Christi Texas 
446 am CST Sat Nov 21 2009 


Short term (today through sunday)...a 1007 mb surface low located 
just east of buoy 42019 will continue to move slowly east-northeastward through 
tonight. The attendant middle/upper closed low is moving through the 
eastern half of the state right now and will continue an eastward trek 
towards Louisiana today. Increasing subsidence and a drying trend will be 
the result as negative vorticity advection and ridging at all levels builds into the County Warning Area from 
the west. Dry and tranquil conditions will persist through the 
remainder of the weekend. Followed the guidance for the forecast highs 
each day. Leaned towards the cooler NAM MOS for the lows given the 
airmass origins and excellent radiational conditions expected. 


&& 


Aviation...the forecast problem today will be the extent of the low 
stratus over the eastern portions of south Texas. Low level moisture 
forecasts and forecast soundings indicate that IFR conditions will redevelop 
westward to around ali through 15z. After that time...ceilings 
should begin to rise to MVFR levels and then slowly erode from 
the west as drier air works into the region. MVFR conditions should 
primarily be limited to the northeast coastal Bend (vct area) 
after 18z. Most of these clouds will diminish by 00z this evening. 
VFR conditions will then be widespread during the evening. Patchy 
fog with MVFR visibilities will begin developing after 06z tonight and continue 
through 15z Sunday across inerior portions of south Texas. Even 
patchy IFR conditions will be possible between 09z and 13z across 
the ali-vct corridor. VFR conditions will then prevail once the fog 
Burns off. 


&& 


Marine...a continued weakening of the northwest winds will occur 
today as the 1007 surface low moves east-northeastward through the northwest and northern 
Gulf of Mexico. Seas will also weaken but will be slower to fall. Will 
issue an Small Craft Advisory for the nearshore waters through 12z and extend the 
Small Craft Advisory for the offshore waters through 20z today. Weak north winds tonight will 
transition to weak east winds by late Sunday as the weak surface ridge axis 
pushes east. 


&& 


Long term (sunday night through friday)...moisture will increase 
through Monday ahead of the next long wave trough and associated cold 
front. A weak embedded short wave in SW flow aloft is forecasted to move 
across S Texas on Monday providing weak upper support and the models 
show sufficient moisture advecting northward into the County Warning Area to produce 
isolate shra's. This continues through Monday night into Tuesday with tsra's 
chances increasing as the cold front moves into S Texas. Cape...Li...Omega 
all increase ahead of the frontal boundary...but the main upper energy 
remains well north of the region and the moisture remains fairly limited 
compared to this past event. Therefore am not expecting heavy rain nor 
severe tsra's. Have kept generally 30 percent on Tuesday with rain chances 
diminishing from north to S through Tuesday night. By Wednesday...precipitation should end 
as high pressure builds across the region and Ushers in much drier and 
cooler conditions. Near normal temperatures will prevail through the 
remainder of the week as high pressure remains in control. An upper 
low is forecasted to move across mex and approach Texas by Friday with a weak 
onshore flow developing and in turn begining a warming trend and 
increasing low level moisture. 


&& 






Preliminary point temps/pops... 
Corpus Christi 72 49 73 58 77 / 0 0 0 10 20 
Victoria 68 46 71 53 77 / 10 0 0 10 10 
Laredo 77 50 80 59 78 / 0 0 0 10 10 
Alice 74 47 76 55 78 / 0 0 0 10 20 
Rockport 71 52 72 59 76 / 0 0 0 10 20 
Cotulla 75 45 76 54 77 / 0 0 0 10 20 
Kingsville 73 47 75 57 78 / 0 0 0 10 20 
Navy corpus 71 54 72 61 75 / 0 0 0 10 20 


&& 


Crp watches/warnings/advisories... 
Texas...coastal Flood Advisory until noon CST today for the following 
zones: Aransas...Calhoun...Kleberg...Nueces...Refugio...San 
Patricio. 


GM...Small Craft Advisory until 2 PM CST this afternoon for the 
following zones: waters from Baffin Bay to Port Aransas 
from 20 to 60 nm...waters from Port Aransas to Matagorda 
Ship Channel from 20 to 60 nm. 


Small Craft Advisory until 6 am CST early this morning for the 
following zones: coastal waters from Baffin Bay to Port 
Aransas out 20 nm...coastal waters from Port Aransas to 
Matagorda Ship Channel out 20 nm. 


&& 


$$ 


Mb/80...short term 
te/81...long term