Let's talk about the weather! The Balcones Fault area of Texas is considered to have a humid subtropical climate (Cfa according to Koppen). The summers are hot and humid with the warm air coming from the Gulf of Mexico, and mild, fairly dry winters. Recently, the record high in Austin was 112 degrees Fahrenheit. Movement of the Polar and Pacific Jet streams encouraged the dry, warm weather putting this area and most of the Midwest in a drought.Though this area of Texas is prone to drought, heavy rains are not uncommon. Large storm systems, as well as hurricanes, move through the Gulf of Mexico towards these areas. While no longer hurricanes when they reach Austin, the storm systems begin slowing over the land and dump rain on the region.
| Flood in central Austin along Shoal Creek |
As warm air from the Gulf of Mexico comes in contact with the escarpment, it rises and can produce rainstorms due to the orographic cooling. The area is also located where the polar air mass and the easterlies converge, sometimes resulting in heavy rains. The rolling hills and steep slopes, along with thinly soil covered limestone bedrock, increase the rate of run-off. The Balcaones Escarpment between Austin and San Antonio is one of the three areas most susceptible to flash floods in the nation.
| Onion Creek flooding in 2010 |
Sources
http://www.tshaonline.org
http://en.wikipedia.org/wiki/Austin,_Texas#Geography
http://impactnews.com/articles/the-memorial-day-flood-of-1981
http://www.lib.utexas.edu/geo/balcones_escarpment/pages1-14.html
