297 
fxus64 kcrp 030548 
afdcrp 


Area forecast discussion 
National Weather Service Corpus Christi Texas 
1148 PM CST Tuesday Dec 2 2008 


Discussion...see aviation discussion below. 


&& 


Aviation...increase of boundary moisture and subsequent increase 
of low level jet to 45 knots and stratus will allow intermittent periods of 
MVFR ceilings from 09z to 13z for terminals east of Highway 77 to the 
coastline. Otherwise...south winds of 8 to 15 knots will dominate 
overnight. With increase of low level jet and nocturnal diurnal slackening 
of surface winds low level wind shear will be present through 16z. 
VFR conditions will prevail after 15z with breezy to windy south 
winds with southwesterly winds immediately above the surface ahead of the 
upper trough and surface front that is forecast to move into the Rio 
Grande plains before 03z (wednesday evening). 




&& 


Previous discussion... /issued 943 PM CST Tuesday Dec 2 2008/ 


Discussion...increase of low level jet and boundary layer moisture expected 
to continue during the overnight hours. Low level jet is expected to 
increase at 40 to 50 knots east of Highway 281 overnight with 
increasing stratus and maritime winds during the overnight hours. 
Have increased cloud cover mainly for areas east of Highway 77 and 
offshore waters with short term models showing rapidly increasing 
boundary layer moisture through the nocturnal hours. Satellite 
imagery shows increasing stratus deck from Bay of Campeche up 
northward into East Texas. Mostly cloudy skies are anticipated 
during the early daylight hours...but partial clearing and afternoon 
temperatures warming to well above normal with southwesterly winds expected above 
the surface. Will update zones to reflect these changes. 


Previous discussion... /issued 754 PM CST Tuesday Dec 2 2008/ 


Discussion...aviation update...low cloud satellite enhancement 
shows region of low clouds forming over the Gulf waters east of 
Rockport. Updated vct taf to show MVFR ceilings developing after 
midnight and continuing until mid-morning. Expect these ceilings 
to be east of a Kingsville-Beeville line. 


Previous discussion... /issued 551 PM CST Tuesday Dec 2 2008/ 


Discussion...see aviation section. 


Aviation...VFR conditions will continue through Wednesday. Low level 
flow will strengthen over the coastal plains tonight as an area of low 
pressure deepens over the southern High Plains in advance of an upper 
level disturbance moving southeast out of the central rockies. Models 
indicated the southerly low level jet will intensify overnight to 
45-50 knots around 1500-2000 feet. Could see isolated pockets of 
stratocu providing MVFR ceilings overnight as this low level jet 
sets up. But most of the models show axis of moisture return to be 
just east of the coastal Bend. Did not show MVFR ceilings in the 
tafs for ali/crp/vct. Did place a mention of low level wind shear 
for the overnight hours to a few hours after sunrise for ali/crp. 
Gusty southerly winds will continue during the day before subsiding 
late in the afternoon as a cold front moves into central Texas. 


Previous discussion... /issued 257 PM CST Tuesday Dec 2 2008/ 


Short term (tonight through Wednesday night)...winds have increased 
today in response to a deepening low pressure system to our west. 
As a result...low level moisture is beginning its return to south 
Texas. With increased moisture and onshore flow in place...low 
temperatures tonight are expected to be significantly higher than 
previous nights...with temperatures ranging from the upper 50s to low 
60s. Breezy conditions are expected Wednesday afternoon ahead of 
an approaching cold front. These south winds ahead of the front 
will lead to above normal temperatures...with afternoon highs in the low 
to middle 80s expected. The front is expected to push through the 
region late Wednesday night. Believe most of the precipitation will stay 
to the north of the area. For now...am only showing slight chance 
probability of precipitation for the extreme northeast counties and then offshore where 
the best instability is prognosticated to be. 


Marine (tonight through Wednesday night)...as the pressure 
gradient continues to increase over the Gulf waters in response to 
a deepening low pressure system to our west...Small Craft Advisory conditions are 
expected to develop by early evening. Winds should remain near Small Craft Advisory 
criteria through the period. 


Long term (thursday through tuesday)...the models are in close 
agreement with the main synoptic pattern through the weekend. A ridge 
axis anchored to our west will intensify through the weekend as several 
S/waves round the base of a persistent eastern United States trough 
axis. Cooler temperatures will prevail on Thursday and Friday as a sprawling 1030+ 
mb surface ridge axis stretching across the southern and Central Plains noses 
into south Texas. The trend in the models has been to develop a weaker 
coastal trough axis each run for Friday. While overrunning is still 
expected...it appears that light precipitation will be mostly confined to the 
coastal counties and the waters on Friday. The overrunning pattern will 
begin breaking down on Friday night and will end totally on Saturday. 
The cloud cover should break up on Saturday to allow temperatures to warm up 
by 10-20 degrees over friday's highs. A continued warmup is expected 
through Monday as return flow gradually increases. The main forecast 
problem of the models is their handling of the closed low along the 
California coast. Most of the guidance is progressive with this 
feature while the GFS maintains this system more as a cut-off low. 
Even with the other guidance...they still differ on the timing. As 
a result...will lean towards the much slower solution of the GFS. Will thus 
continue a moderate return flow into Tuesday while the other models 
depict a frontal boundary approaching the County Warning Area. Will maintain the above 
normal temperatures and mostly cloudy conditions through Tuesday. 


&& 


Preliminary point temps/pops... 
Corpus Christi 58 83 52 64 49 / 10 10 10 10 10 
Victoria 56 80 45 61 38 / 10 10 20 10 10 
Laredo 55 86 50 67 47 / 0 0 0 0 10 
Alice 54 84 49 65 46 / 0 10 10 0 10 
Rockport 63 79 53 62 47 / 10 10 20 10 10 
Cotulla 53 81 46 66 40 / 0 0 0 0 10 
Kingsville 57 84 52 65 47 / 10 10 10 10 10 
Navy corpus 65 79 55 63 54 / 10 10 10 10 10 


&& 


Crp watches/warnings/advisories... 
Texas...none. 
GM...Small Craft Advisory until 6 PM CST Wednesday for the following 
zones: bays and waterways from Baffin Bay to Port Aransas... 
coastal waters Baffin Bay to Port Aransas out 20 nm... 
coastal waters Port Aransas to Matagorda Ship Channel out 
20 nm...waters Baffin Bay to Port Aransas 20 to 60 nm... 
waters Port Aransas to Matagorda Ship Channel 20 to 60 nm. 


&& 


$$ 


SC/70...short term 
wc/87...long term 

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