Weather

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Area forecast discussion 
National Weather Service Brownsville Texas 
130 PM CDT Thursday Aug 7 2008 


Discussion...with upstream 500 mb ridging dominating the large scale 
weather pattern aloft...and high pressure over the northwest Gulf of 
Mexico controlling local conditions...there should not be a lot of 
sensible weather variation in the short term and persistence will 
rule the forecast. 


The ridging pattern over the western U.S. Will eventually begin to 
flatten over the weekend however as short wave troughs moving west to east 
along the northern U.S. Border move through. The ridge will then 
tend to rebuild early next week. Meanwhile...high pressure will 
remain dominant in the northwest Gulf. The pressure over the Texas 
Panhandle will decrease late in the weekend as an 500 mb short wave trough 
moves through the ridge...inducing height and pressure falls down 
stream. Winds will pick up over the marine areas early next week as 
the pressure gradient tightens...but winds over the land areas will 
not be affected very much as lower pressure dips farther south and 
closer to deep south Texas...keeping the gradient loose. 


The Panhandle system will shift east Monday and Tuesday...with 
higher pressure then working its way back into north and West Texas 
from upstream. Convection over those sections of the state may be a 
little more active through the forecast as middle level energy moves 
overhead and triggers instability along moisture gradients. 


Atlantic tropical weather remains relatively inactive for the time 
being. 


In terms of the ongoing forecast...just freshened up the wind grids 
with new data and tweaked temperatures a degree or two here and there. No 
major changes were required. 
&& 


Previous discussion...issued at 900 am CDT Thursday Aug 7 2008...broad 1015 
mb high is established in the northwest Gulf this morning. Isolated 
light shower activity persists over the open Gulf to the east of the 
County warning forecast area. The latest sounding and observation indicate scattered to broken higher clouds 
across the area. The precipitable water is lower this morning than yesterday... 
when a less than definite line of sea breeze showers developed. 
There are no probability of precipitation in the current forecast for this afternoon...but 
will let this stand given the drier sounding. Afternoon sea breeze 
showers can be handled with short term forecasts. No changes needed 
to the forecast this morning. 


Tropical activity remains unremarkable for the moment. An upstream 
500 mb ridge over the western third of the country is bisected by the 
Continental Divide and will remain dominant in the short term... 
effectively blocking any large scale weather systems from affecting 
deep south Texas. 
&& 


Marine...at 1pm this afternoon...buoy 020 reported a southeast wind 
at 6 knots with seas of 2.5 feet. High pressure located over the 
northern Gulf of Mexico is keeping winds and seas light. The feature 
is expected to remain in place the rest of the week into the 
upcoming weekend. Therefore...winds and seas are expected to remain 
light through this time period. Some change is expected early next 
week as low pressure develops in the Central Plains. This will 
increase our winds to possibly near advisory criteria. A few light 
showers are possible during the next few nights. 
&& 


Aviation...a couple showers along the sea breeze could impact 
aviation concerns along the coast the next couple hours. Cloud cover 
should begin to thin out closer to sunset with the loss of daytime 
heating. VFR conditions are expected for most of the next 24 hours. 
&& 


Preliminary point temps/pops... 
Bayview 078 094 078 094 079 095 / 005 005 005 005 005 005 
Brownsville 077 095 077 095 078 096 / 005 005 005 005 005 005 
Falfurrias 074 098 076 099 075 097 / 005 005 005 005 005 005 
Harlingen 076 097 076 097 076 098 / 005 005 005 005 005 005 
Hebbronville 074 098 073 100 075 098 / 005 005 005 005 005 005 
McAllen 077 099 078 099 078 099 / 005 005 005 005 005 005 
Port Isabel 079 093 079 093 079 093 / 005 005 005 005 005 005 
Rio Grande City 078 102 077 101 075 102 / 005 005 005 005 005 005 
South Padre Island 080 091 080 091 079 092 / 005 005 005 005 005 005 
&& 


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


$$ 


54/57/64/Martinez 


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http://www.Weather.Gov/Brownsville