120 
fxus64 kcrp 212322 aaa 
afdcrp 


Area forecast discussion...updated 
National Weather Service Corpus Christi Texas 
522 PM CST Sat Nov 21 2009 


Discussion...updated for 00z aviation discussion. 


&& 


Aviation...VFR conditions are in place across the entire region 
except for the northeast corner where MVFR ceilings remain in the 
wake of the low pressure system departing to the east. For portions 
of the coastal plains where skies are clear along and east of a 
line from Tilden to Freer, moist low levels will lead to areas of 
LIFR/IFR ceilings/visibilities mainly after 05z. Over the northeast where 
MVFR ceilings linger this evening, cloud bases will slowly lower 
overnight to LIFR/IFR with LIFR/IFR visibilities developing there as 
well. VFR conditions will return to the entire area by roughly 17z 
Sunday morning. 


&& 


Previous discussion... /issued 315 PM CST Sat Nov 21 2009/ 


Short term (tonight through Sunday night)...clouds out to the 
northeast are finally starting to erode...and generally expect 
these to continue to scatter out but will monitor and make any 
last minute changes if needed. Main issue the next two days will 
be fog. With much drier air light winds and very wet grounds...fog 
will likely occur. Whether it be sufficiently dense over a large 
area is the main question...and for now will not issue any dense 
fog advisory yet as not totally confident in areal coverage... 
although kali and kvct will be prime suspects...the latter as long 
as the clouds do not linger. Have mentioned areas of fog with 
patchy dense fog for now...afternoon shift can adjust as needed. 
Once the fog clears...should see mainly sunny skies for most of 
the day...with clouds increasing slightly from the south during 
the afternoon over southern areas. Light winds and weak moisture 
advection (again with wet grounds and light winds) should bring 
fog back again on Sunday night. For temperatures...went on the low 
side or below guidance by a degree or two...especially out west 
where drier air resides. Highs for Sunday should be mainly in the 
70s...with perhaps 80f in Laredo. About a 5 to 7 degree warm up 
most locations on Sunday night/Monday morning...as moisture and 
onshore flow return. 


Long term (monday through saturday)...areas of fog will start the 
period Monday in a weak warm advection scenario and maybe slow to 
clear due to light boundary layer winds. Potent trough moving 
across the Central Plains will draw moisture and cloud northward 
across the County Warning Area Monday afternoon and night ahead of a cold front. Expect 
a slight chance of showers and thunderstorms Monday as instability and 
moisture increases with a chance of probability of precipitation Monday night and Tuesday as the 
front moves through. Light winds...saturdated soils and weak 
boundary layer moisture advection could lead to fog redeveloping 
again Monday night-Tuesday am. Front is still on track to move through 
around midday Tuesday. Dynamics are prognosticated to be weak and 850 mb winds 
westerly ahead of the front...thus will under cut the GFS MOS probability of precipitation 
and indicate only 40-50%. Convection may be more pronounced over 
the coastal waters and to our south as GFS/European model (ecmwf) hint at some jet 
dynamics/difluence aloft in those areas. Precipitation will end from north to 
south Tuesday night as the front moves into the northwest Gulf...with a strong 
offshore flow developing in its wake. Tranquil conditions will 
persist through the remainder of the week as a secondary surge of 
high pressure settles into south Texas. The GFS keeps US dry through 
the weekend while the European model (ecmwf) shows a more progressive southern jet. 
Kept the dry scenario for now...but future shifts may have to 
consider adding probability of precipitation. 


Marine (tonight through Sunday night)...offshore flow will 
continue to decrease...then become onshore late Sunday with a weak 
to moderate onshore flow Sunday night. Seas subsiding to 2 to 3 
feet by Sunday. 


&& 


Preliminary point temps/pops... 
Corpus Christi 50 73 56 76 63 / 0 0 10 20 30 
Victoria 45 71 50 76 60 / 0 0 0 10 30 
Laredo 51 80 57 78 62 / 0 0 0 20 30 
Alice 48 76 54 77 61 / 0 0 10 20 30 
Rockport 53 71 58 75 64 / 0 0 0 20 30 
Cotulla 46 74 52 76 60 / 0 0 0 20 30 
Kingsville 46 75 54 77 62 / 0 0 10 20 30 
Navy corpus 55 72 59 74 64 / 0 0 10 20 30 


&& 


Crp watches/warnings/advisories... 
Texas...none. 
GM...none. 


&& 


$$ 


Wc/87...short term 
jar/19...long term/aviation