972 
fxus64 kcrp 131543 aaa 
afdcrp 


Area forecast discussion...updated 
National Weather Service Corpus Christi Texas 
1043 am CDT Monday Oct 13 2008 


Discussion...boundary layer and middle level dry air is prognosticated to 
come into the area later this afternoon...which should begin to 
inhibit rainfall potential. However...both NAM and GFS is showing 
a bit of 850mb moisture advection during the afternoon over the 
southeastern areas which will impact much of the southern counties 
of the County warning forecast area through part of the afternoon. Thus...maintained the 
30/40 probability of precipitation over the south but did lower them most other locations 
for this afternoon. Previous forecast does have the drier air move 
in tonight (evidenced by sky cover and pop forecast) so for now 
did not make any changes beyond the first period. 


&& 


Previous discussion... /issued 419 am CDT Monday Oct 13 2008/ 


Short term (today through tuesday)...00z Monday soundings showed a 
moist tropical airmass in place across S Texas west/ precipitable waters  in excess of 2 
inches over deep S Texas. This moisture has moved north...especially into 
areas west of I-37. Models indicate drying from east to west through the 
day today west/ decreasing precipitable waters ...but appears enough moisture and low 
level instability are in place to maintain scattered probability of precipitation favoring western 
areas where moisture axis exists. Given an improving but still 
warm 700 mb-500 mb layer will refrain from mentioning any thunderstorms today. The 
middle-upper level ridge over the region will weaken and split by Tuesday due 
to upper low across the cen rockies to the northwest and upper low to the southeast 
across the Gulf. This will lead to cooling of a very warm 700 mb-500 mb 
layer that has been in place across S Texas. Meanwhile...the Erly 
wave to the south will inject higher moisture into the area once 
again after a brief dry pocket late the afternoon and tonight. Although 
timing may be a bit off west/ the highest moisture arriving in the 
afternoon...much improved thermal profiles associated west/ aforementioned 
700 mb-500 mb cooling will likely lead to another round of scattered convection 
across the region west/ better chances of some deeper convection and 
thunderstorms as well. Mav probability of precipitation ranging from 20-40% favoring the east look 
fine for now on Tuesday...but big story will be even better rain chances 
the next few days as discussed below. 


Long term (tuesday night through sunday)...GFS/ECMWF are in general 
agreement depicting an upper trough over the central rockies/plains 
with strong high pressure centered in the vicinity of Georgia at the 
beginning of the period. While the models differ on low level wind 
fields, they are in much better agreement that abundant tropical 
moisture will be pushing into the forecast area with precipitable 
water values ranging from 2.0 to 2.3 inches Tuesday night through 
Thursday. The European model (ecmwf) has come into agreement with the GFS that a 
front approaching the region from the north on Wednesday will stall 
to our north and not be a factor. However, inverted troughs/easterly 
waves rounding the upper high over the southeast U.S. Will interact 
with the abundant moisture over south Texas for scattered to 
numerous showers/thunderstorms Wednesday and Thursday. For Friday, 
the European model (ecmwf) shows that an upper trough will sweep through eastern 
Texas and an associated surface cold front will push through south 
Texas. The GFS does not really show either of these features. Either 
way, residual but decreasing tropical moisture and daytime heating 
will keep slight chances of showers/thunderstorms in the forecast 
for Friday. Late Friday into Saturday, both models indicate high 
pressure aloft will build into central or eastern Texas with rapidly 
decreasing moisture amidst a low level northeast to east flow. Dry 
conditions will prevail Saturday/Sunday as surface high pressure 
passes to the east allowing an onshore flow to return. High 
temperatures look to remain above normal through the entire period, 
though abundant cloud cover may get US down to near or slightly 
below normal Thursday and Friday. 


&& 


Preliminary point temps/pops... 
Corpus Christi 87 73 86 74 86 / 30 10 40 30 60 
Victoria 88 70 86 71 86 / 20 10 40 30 60 
Laredo 92 74 93 75 88 / 30 20 20 20 40 
Alice 90 71 88 71 87 / 40 10 40 30 60 
Rockport 87 75 84 75 86 / 30 10 40 30 60 
Cotulla 89 71 91 71 87 / 30 20 20 30 40 
Kingsville 88 71 87 72 86 / 40 10 40 30 60 
Navy corpus 86 79 85 76 84 / 30 10 40 30 60 


&& 


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


&& 


$$ 


Gw/86...short term 
kr/97...long term