886 
fxus64 kcrp 040454 aac 
afdcrp 


Area forecast discussion...updated 
National Weather Service Corpus Christi Texas 
1154 PM CDT Thursday Jul 3 2008 


Aviation...maintain pretty much sea-breeze scenario forecast in the 
terminals with plentiful moisture...no cap and weak wind regime. 
Winds and ceilings will be somewhat persistence. Generally will see VFR 
conditions except in heavier storms where ceilings and/or visibilities could be 
at or below MVFR. For now...will not go any lower than MVFR conditions for 
the tempo groups...and these have been situations where tempo groups 
have worked out better than having categorical rain showers/thunderstorms and rain in the 
forecast taf. 


&& 


Previous discussion... /issued 904 PM CDT Thursday Jul 3 2008/ 


Update...except near the Rio Grande and Laredo...rain has ended 
this evening. Could see some isolated inland activity mainly near 
the coast overnight...otherwise convection expected to develop 
once again in the Gulf toward morning and get the diurnal 
convection again. Previous forecast has this OK for now so no 
changes after the first period. First period changes were mainly 
to lower/end rainfall chances and nudge temperatures down a degree or so 
(based on this morning's lows and current dew points). Other 
minor adjustments to other first period grids (mainly clouds). 


Previous discussion... /issued 657 PM CDT Thursday Jul 3 2008/ 


Aviation...not much convection expected ovrnite leading to 
generally VFR conditions. However...toward Friday morning am 
expecting scattered shra's/tsra's to spread westward across S Texas leading 
to IFR conditions briefly at times through Friday afternoon. 


Previous discussion... /issued 342 PM CDT Thursday Jul 3 2008/ 


Short-term (tonight through Friday night)...the GFS forecasts 
the upper trough axis to move over the County warning forecast area by early Friday...and 
become quasi-stationary...yet the NAM forecasts the trough to remain 
over the western Gulf...in response to the ridge to the west/northwest building 
more strongly over the County warning forecast area...and resulting in lower precipitable water values/ 
greater subsidence. Yet most of the GFS ensembles adds credence to 
the GFS deterministic solution. Concur with the GFS. Thus still expect 
copious moisture/instability and the quasi-stationary upper low to 
contribute to generally scattered convection drg the period...with the 
bulk of the activity over the waters drg the early morning hours 
and over the land drg the daytime hours. Expect the lack of a 
quasi-stationary synoptic/mesoscale boundary to preclude widespread 
heavy rain. Thus will not issue an flash flood advisory. Expect maximum temperatures in the 
upper 80s/lower 90s Friday. Expect maximum heat index values to remain 
below 105f Friday. 


Long-term (saturday through thursday)...remain fairly confident in 
overall wet pattern continuing through next week...however 
confidence is low regarding details of which days will be more or 
less active as models are not in good agreement regarding subtle 
movement in weak upper trough and movement of moisture. First 
off...have thrown the NAM solution out as its depiction of a sharp 
850 mb-700 mb trough across the Gulf waters west/ ridging and strong drying 
building into the coastal Bend from the north-northeast is a total outlier. On 
the other end of the spectrum...the European model (ecmwf) (00z run) retrogrades a 
sharpening middle-upper level trough quickly back into cen Texas over the 
weekend...opening the door for very deep tropical moisture to 
continue to move inland across S Texas (as seen in 80-90% 1000-500mb relative humidity 
fields). The GFS (deterministic and ensembles) show a weak and more 
broad upper trough remaining quasi-stationary near the coast or just 
inland...W/ moisture just slightly decreasing in the near term then 
increasing significantly by Tuesday with a tropical wave (currently 
around 70w) moving into S Texas and Mexico. The European model (ecmwf) also supports the 
secondary moisture surge...but has been a bit faster west/ its arrival. 


With all that in mind...will lean toward the compromise GFS solution 
which still suggests scattered diurnal probability of precipitation inland west/ isolated to scattered mainly 
morning convection over the waters. Best chance for rain will likely be 
the coastal plains areas between Highway 77 and Highway 16 unless 
the upper ridge to the northwest builds in enough to provide more 
subsidence/drying across inland cos. Tough to go more than scattered probability of precipitation 
next week given uncertainty west/ timing of weak wave and deep tropical 
moisture plume...but will at least show higher end scattered probability of precipitation to 
indicate increasing rain chances. If the GFS pans out probability of precipitation will end up 
in the likely Cat at least Tuesday and Wednesday west/ heavier rainfall and 
higher rain chances initially shifting to the coastline early during 
the event. 


Convection will continue to provide below normal temperatures through the 
period...although temperatures will warm some from recent readings during 
the middle periods of the forecast. Also...should point out that 
although scattered probability of precipitation are in the forecast daily...rainfall will 
generally last less than 2 hours and total washouts are generally 
not expected. If the tropical wave around middle next week verifies... 
that could change. 


&& 


Preliminary point temps/pops... 
Corpus Christi 74 88 75 90 74 / 20 50 30 50 20 
Victoria 71 90 73 91 73 / 20 40 30 40 10 
Laredo 76 94 76 95 77 / 40 40 40 40 20 
Alice 72 90 73 92 73 / 10 50 30 50 10 
Rockport 78 86 77 89 78 / 30 40 30 40 20 
Cotulla 72 91 73 93 73 / 30 40 40 40 20 
Kingsville 74 89 73 91 73 / 20 50 30 50 10 
Navy corpus 78 86 77 89 78 / 30 40 30 40 20 


&& 


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


&& 


$$ 




Gw/86...aviation