317 
fxus64 kbro 182043 
afdbro 


Area forecast discussion 
National Weather Service Brownsville Texas 
345 PM CDT Friday Jul 18 2008 


Discussion...the current kbro radar reflectivity shows an area of 
diurnally driven conv firing up south of Hidalgo County moving north 
along the Highway 281 corridor. The middle to upper level lows 
currently near the Texas coastline will steadily move west this weekend 
which will maintain some decent upper level divergence over the bro 
County Warning Area. In addition...daytime heating over the next several days will 
also help destabilize the atms in the afternoon and early evening 
hours helping generate more isolated conv through sun. As these middle and 
upper level lows shift further west...the 500 mb ridging will 
rebuild over the Lower Texas coastline late sun into Monday which will dry 
out and stabilize the atms. The current met temperatures are a little 
warmer versus the mav and these may be a bit overdone considering 
the expected isolated afternoon and early evening conv and cloud 
cover. Believe that the GFS mav is handling this a bit better so 
will go with the slightly cooler GFS temperatures. The mav/met and FWC visibility 
guidance all point towards no fog for the next several nights and 
this looks reasonable considering the lack of fog from the past 
several mornings. So will not mention any nighttime or morning fog 
at this time. In the longer range...the situation becomes very 
interesting for deep south Texas as NHC continues to closely monitor a 
strong tropical wave in the central Caribbean Sea for possible 
development. This feature continues to move quickly west at around 
20 miles per hour. This system will move into Central America and the Yucatan 
Peninsula late sun eventually emerging out into the SW Gulf on Monday. 
How much of an impact on weather conditions across deep south Texas will be 
highly dependant on the overall track of this feature next week. The 
GFS and European model (ecmwf) are in general agreement in an overall west-northwest motion of 
this feature into next week. Believe that regardless of the level of 
development with this feature...enough deeper tropical moisture will 
advect north to increase the conv chances in the 3 to 7 day range. Will 
include a mention of chance probability of precipitation here with a little lower temperatures due to 
the better cloud cover. Residents of deep south Texas should continue to 
monitor closely the progress of this system and stay tuned to the 
latest statements and forecasts from the National Hurricane 
Center. 
&& 


Aviation...VFR conditions will dominate the regional airports for 
the next 24 hours. Winds will be light from the southeast through 
Saturday. 
&& 


Marine...at 12 noon buoy020 reported south to southeast winds at 6 
to 8 kts and seas of 1.3 feet at 3 seconds. High pressure will 
continue to cause a weak flow over the western Gulf with light winds 
and very low swells through the weekend. An upper level low 
pressure system could cause some isolated showers or thunderstorms 
in the Gulf today and Saturday. However...a relatively dry and 
stable weather pattern will continue through the beginning of next 
week. 
&& 


Preliminary point temps/pops... 
Bayview/Port Isabel 77 92 78 91 / 10 20 10 20 
Brownsville 75 94 77 94 / 10 20 10 20 
Harlingen 74 95 75 95 / 10 20 10 20 
McAllen 75 97 76 97 / 10 20 10 20 
Rio Grande City 75 96 75 97 / 10 20 10 20 
South Padre Island 78 88 79 88 / 10 20 10 20 
&& 


Bro watches/warnings/advisories...none. 
&& 


$$ 


This product is also available on the web at: 
http://www.Weather.Gov/Brownsville 


Short term forecast products available on the web at: 
http://www.Weather.Gov/Brownsville/graphicast 


Synoptic/grids...60 
marine/aviation...65 
meso/fxc...Hart