997 
fxus64 kcrp 160559 aaa 
afdcrp 


Area forecast discussion...updated 
National Weather Service Corpus Christi Texas 
1259 am CDT Thursday Oct 16 2008 


Discussion...see aviation discussion. 


&& 


Aviation...somewhat diffuse cold front currently located just 
north of vct to lrd will slowly move through the region. This will 
provide increasing rain showers activity...especially across coastal Bend 
remainder of the night with some thunderstorms possible...especially near the 
coast. This will also lead to a mix of IFR and lower end MVFR 
conditions for remainder of the night and lingering MVFR the first 
half of Thursday as moisture lingers behind the front. A weak 
disturbance could lead to additional scattered Post frontal precipitation 
through early Friday...but ceilings will likely raise above MVFR levels 
by this afternoon as some drier air near the surface slowly is advected into 
the region. 


&& 


Previous discussion... /issued 1053 PM CDT Wednesday Oct 15 2008/ 


Discussion...frontal boundary is a little ahead of schedule with 
the boundary located from south of a Victoria to Laredo line at 03z. 
00z crp sounding continues to show abundant moisture in place over 
south Texas in advance of this boundary with preciptable water 
values around 2.1 inches which is between 150 and 200 percent of 
normal. Low level moisture convergence will continue to be 
maximized along the frontal boundary overnight across the region. 
Another positive factor will be the upper level jet streak moving 
up from deep south Texas on the east side of the upper low that 
is moving northwest into southern coahuila. GFS/NAM show that 
upper level divergence will be increasing overnight on the nose 
of this jet streak moving into the forecast area. Will retain 
categorical probability of precipitation for the overnight period. If some of this 
activity trains over the same region for a few hours...locally 
heavy rain will be possible. Flash flood guidance values remain 
high over the forecast area so will not go with watch at this 
point. 


Tides came up to 2.3 feet mean sea level at bob Hall pier at high tide 
earlier this evening. Tides remain about a foot above expected 
levels while the bays are about 0.8 feet above expected. Will 
continue the statement regarding minor tidal overflow through 
tomorrow evening with high tide at Port Aransas at 701 PM. 
.Corrected high tide time for Port Aransas... 


Previous discussion... /issued 632 PM CDT Wednesday Oct 15 2008/ 


Discussion...see aviation discussion. 


Aviation...scattered to num shra's and isolate thunderstorms and rain will be the primary 
concern through tonight as a frontal boundary slowly drifts through S 
Texas. This will lead to brief MVFR/IFR conditions where rain showers are 
located. These conditions will continue through Thursday 
morning...however am expecting precipitation to become more stratiform 
-ra by afternoon with a ceiling above 3kft as a shallow dry airmass 
filters across S Texas from the north. 


Previous discussion... /issued 320 PM CDT Wednesday Oct 15 2008/ 


Short term...main focus this package is on precipitation out 
ahead of a cold front moving through south Texas in the short 
term. Numerous showers have broken out this afternoon over the 
coastal Bend and Victoria Crossroads as copious moisture interacts 
with weak dynamics. Expect this activity to continue through 
early evening...gradually shifting west as moisture fights through 
drier air. Activity will then regenerate overnight as the front 
approaches. Model forecasts bring the front through from early 
morning hours northwest to just after sunrise southeast. Drier air 
lags the front significantly...so more showery precipitation can be 
expected behind the front through the rest of the short term. 
Light winds will turn north behind the front. 


Coastal flood statement remains in effect as east fetch and 
astronomical high tides combine to raise levels. Effect should 
diminish somewhat after frontal passage Thursday as surface winds swing around. 


Aviation...conditions will deteriorate as the front 
approaches...with ceilings lowering to MVFR. Visibilities may also become 
MVFR in showers...with occasionally IFR ceilings. Winds to turn north 
after frontal passage...with ceilings remaining down. 


Long term (friday through wednesday)...cold front will be located 
well offshore Friday morning. Higher moisture pool axis (of around 
2" pws) will actually reside behind the front...or across the 
southeast half of the County Warning Area and marine zones. Models keying in on quantitative precipitation forecast 
along very weak 850 mb convergence axis along the coast Friday 
morning...but think this may be slightly overdone this far 
north...and as such think the MOS values for probability of precipitation Friday are 
slightly high. Undercut 12z MOS probability of precipitation by about 20%. Despite this 
thinking...cloud cover behind the front will be slightly slower to 
clear from south to north than previously thinking...but will clear 
Friday night and early Saturday morning as northwest flow aloft 
develops in response to ridging over West Texas. 


Should be a nice weekend...with winds returning onshore Sunday as 
high pressure moves east. Will see overnight lows slowly coming 
back up early next week as moisture slowly returns. 


Forecast middle week and just beyond day 7 uncertain now...as models 
have been having very difficult time with placement and strength of 
upper level low cutting off to the north or northwest and associated 
cold front through our area just beyond day 7. European model (ecmwf) has actually 
had poor run to run consistency...showing in the 00z run the upper 
level low cutting off over the southwest U.S. Midweek...and now 
showing in the 12z run over the upper Midwest. GFS has been 
indicating over the plains. See hpc's pmdepd for further information. 


&& 


Preliminary point temps/pops... 
Corpus Christi 79 66 81 64 82 / 80 60 30 10 10 
Victoria 75 62 81 56 82 / 60 40 20 10 0 
Laredo 76 66 81 64 84 / 50 30 10 10 10 
Alice 77 64 81 62 83 / 70 50 30 10 10 
Rockport 79 66 81 64 81 / 80 50 30 10 10 
Cotulla 76 63 82 58 84 / 40 30 10 10 0 
Kingsville 79 67 81 64 83 / 80 60 30 20 10 
Navy corpus 79 68 80 67 80 / 80 60 30 20 10 


&& 


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


&& 


$$ 


Mjg...aviation