Rio Grande Valley
The U.S. Drought Monitor has released its latest weekly update on drought conditions around the nation today (7/7/2011). As expected, none of the Rio Grande Valley is under the “D4-Exceptional” drought anymore. However, western Hidalgo County as well as all of Starr County are under a “D3-Extreme” drought, one step before “exceptional”. The rest of the Valley is under a “D2-Severe” drought. This means that the entire Valley is still considered to be under drought conditions. As I said in my previous blog post, most of the Valley is still well below rainfall averages for the year.
Mid-level ridging continues to dominate over the area, which is keeping the atmosphere stable in the Valley. Things should be dry for most of the Rio Grande Valley over the next 2 to 3 days, with a slight chance of a quick shower or two each day from the sea breeze. There is an upper-level low, visible at 300mb, that will be making its way toward the northwestern Gulf of Mexico by the start of the weekend, but models are keeping the system dry for the Valley until Sunday. Models show a weakness in the 700mb ridge on Saturday and Sunday, enough to provide a better chance at some showers or thunderstorms for Sunday and Monday with the influence of the upper-level low edging closer to southern/central Texas, though it is unclear right now about the quantity of precipitation (QPF) the Valley will receive, if any.
GFS forecasting model at 300mb:
Edinburg’s 3-day Forecast