18 Oct Notes from the TX State Climatologist
I recently heard John Nielsen-Gammon, the State of Texas's climatologist, speak about the science behind the current drought in Texas and what we can expect in the future. His presentation, loosely, was titled, "Texas Drought: Why You Should Get Used to It."
In the past six months, Texas has received six inches of rain, compared to a 110 year historical average of 18 inches. This is our worst drought on record, with the closest competitor in 1956. The 1980s and 1990s were unusually wet decades, averaging far more precipitation than historical weather and tree ring records show. This year has set the record for the worst nine month cumulative dryness of any single year on record. The last time we had a "major precipitation system in Texas was Sept. 27, 2010, but parts of East Texas were already slipping into the drought. By March 2011, the drought had started statewide. By August, the coloration of the U.S. Drought Monitor drought chart no longer did justice to showing the severity of Texas’s 2011 drought.
Gammon said the current drought is somewhat of a natural cycle, and is somewhat of a correction in relation to wetter than usual decades. He added the current drought appears to be markedly exacerbated by global warming.
By Oct. 10, 2011, things began improving slightly. However most of the state is at less than 50 percent of the norm for a 12 month precipitation accumulation period. In addition to the drought, the heat in 2011 has been exceptional. Texas temperatures are running neck and neck with Oklahoma’s as to who will have the hottest summer on record for the U.S., 2011.
Looking to the future, a confluence of climatological, meteorological, and hydrological factors all implies that future droughts will be HOTTER. Current ocean temperatures and La Niña strengthen the possibility of future droughts being even hotter. Climate models say we’re looking at a weak to moderate La Niña for the rest of this year, meaning below normal rainfall, above normal temperatures. Global studies indicate that rainfall should increase everywhere except Texas in the next 20 years. The evidence seems to be expanding that the worst possible conditions (a cold tropical pacific and a warm Atlantic Ocean) are increasing. However, and as always in climate science: It’s not clear which factors are going to win.
"It is not yet fully understood the value of trees and vegetation in helping to manage evaporation, hydrological systems, and high heat. It is believed that less moisture in the system means more intense heat," said Gammon.
His closing point: "If you want a better forecast, check back in five years."
In John's opinion, this is the time for water planning.
Takeaways
This is the time for water planning.
What if we have 4 more years of 70-80% below normal precipitation?
Time to change our response to drought. Some ideas:
> Take actions according to months of the year
> Take actions according to whether we’re in an El Nino or La Nina
More Info
Office of the State Climatologist: http://atmo.tamu.edu/osc/
John’s blog: http://blog.chron.com/climateabyss/
This article edited by Karie Meltzer of AustinPost.org.
No Comments