Jim Spencer

Hundreds of area rainfall totals

September 13th, 2014 at 4:40 pm by under Weather

CLICK HERE to go to our rainfall page to see hundreds of local, up-to-the-minute LCRA hydromet rain totals. Here are rainfall totals from the COCORAHS reports, but these do not include much of the rain that fell during the day Saturday.

COCORAHS PRECIPITATION SUMMARY
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1124 AM CDT SAT SEP 13 2014

COCORAHS PRECIPITATION REPORTS
THESE REPORTS ARE CONSIDERED SUPPLEMENTAL AND UNOFFICIAL
VALUES ARE FOR THE PREVIOUS 24 HOURS ENDING AROUND 7 AM LOCAL TIME
:
:COCORAHS PRECIPITATION REPORTS FOR THE LOCAL AREA
:
:                                               SNOW   SNOW  WATER
:                                        PCPN   FALL  DEPTH  EQUIV
:
TX-TV-125 : MANOR 5.5 SSE            *   : 3.30 /  MM /   MM /   MM
TX-CML-53 : BOERNE 10.2 E            *   : 2.82 /  MM /   MM /   MM
TX-TV-59  : TANGLEWOOD FOREST 0.6 NE *   : 2.81 /  MM /   MM /   MM
TX-TV-205 : TANGLEWOOD FOREST 1.9 NNE*   : 2.70 /  MM /   MM /   MM
TX-HYS-28 : MANCHACA 2.1 ENE         *   : 2.67 / 0.0 /   MM /   MM
TX-HYS-55 : MOUNTAIN CITY 6.7 WNW    *   : 2.65 /  MM /   MM /   MM
TX-TV-113 : AUSTIN 7.3 SW            *   : 2.52 /  MM /   MM /   MM
TX-HYS-60 : DRIFTWOOD 5.0 S          *   : 2.48 /  MM /   MM /   MM
TX-TV-217 : TANGLEWOOD FOREST 2.7 E  *   : 2.45 /  MM /   MM /   MM
 (more...)

Nice rain totals from Friday’s cold front

September 12th, 2014 at 9:47 pm by under Weather

See a comprehensive list of LCRA rain gauge reports here.

9-12 rain totals


Front becoming stationary; rain chances increase

September 11th, 2014 at 8:36 pm by under Weather

The cold front that moved into Central Texas Thursday afternoon was pulling up stationary Thursday night, and isn’t expected to move completely through the area for another 24 hours. That will set the stage for periods of rain and some thunderstorms through Friday night, possibly lingering Saturday morning. Rainfall totals in excess of 2 inches will be possible in some spots.

9-11 RAIN NEXT 5 DAYS

Click for latest Composite Reflectivity radar image from the Austin/San Antonio, TX radar and current weather warnings
NWS graphic

September bird forecast

September 10th, 2014 at 3:44 pm by under Weather

What to watch for in September: Arrivals and departures

Here’s the Central Texas bird forecast for the month, courtesy of Travis Audubon. Learn more about Central Texas birds and bird-related events for all ages at travisaudubon.org or by calling 512-300-BIRD. Travis Audubon is on Twitter and Facebook. Follow us on Twitter @TravisAudubon and give us a like at www.facebook.com/travisaudubon.

Northern Shoveler photo by Stefan Berndtsson via Creative Commons

Northern Shoveler photo by Stefan Berndtsson via Creative Commons

Shoveler sightings
 

Northern Shovelers begin to trickle in during September (they are an early fall migrant returning from their summer grounds in the northern U.S. and Canada). By the end of the month, our lakes and ponds will be full of them, especially along the marshy edges. Watch for a dabbling duck (meaning it does not dive for its food). Shovelers have long and distinctive spoon- or shovel-shaped bills. This time of year the male birds will have blackish bills, brownish-black heads with light speckles, black backs and light brown flanks; the females have lighter bills and are grayish-brown with some dark feathers with light edges. By December the males will sport stunning green heads, white breasts and reddish flanks.

 
Shovelers have an interesting feeding behavior with those enormous bills. According to Borealbirds.org, the ducks’ beaks are designed to sift through muddy water for vegetation and aquatic insects. Their bills have comb-like appendages along the edges, called lamellae, which filter food from the water. As the shoveler moves its head from side to side, water is drawn in at the tip of the bill, filtered through the lamellae to get the food, and then expelled. You often see rafts of these ducks with their necks outstretched, bills in the water, busily foraging.


Farewell to Green Herons


If you walk Lady Bird Lake you may notice that the number of Green Herons, our smallest heron, will diminish
as the month wears on. These stocky dark birds tend to winter in Mexico. They have some fun tricks for nabbing dinner. They often will sit perfectly still for long stretches awaiting a fish or a frog to spear with their beak, but they also have been known to use twigs or insects as bait for fish. It’s one of the world’s few tool-using bird species, according to the All About Birds website.

 
Monthly Meeting — Biodiversity in Texas: Connecting the Past, Present, and Future
6 p.m. Thursday, September 18, Hyde Park Christian Church, 610 E 45th St.

As naturalists, we see only a snapshot in ecological time. However, naturalists from the past give us a valuable perspective on how our local biodiversity has changed over time. In this presentation, Travis Audubon board member and Texas Parks and Wildlife Department naturalist Cullen Hanks will profile different species of birds and reptiles, exploring perspectives from the past, and what we know about them in the present. In the process, he will highlight some of the resources from the past that are available to naturalists in Texas. Cullen will also demonstrate the value of current tools for documenting your observations. By understanding our past and our present, we will be better prepared to detect patterns of change, and to advocate for biodiversity in the future.

Field Trips — Beginners welcome. Check the Travis Audubon website for details.

http://travisaudubon.org/get-outdoors/field-trips

A Swift Night Out! – Multiple Chimney Swift Roosts Across Austin
Friday, September 12, 7 to 8 p.m.

A Swift Night Out! – Multiple Chimney Swift Roosts Across Austin
Saturday, September 13, 7 to 8 p.m.

Jonestown Chimney Swift Roost
Saturday, September 13, 7:15 to 8:15 p.m.

Monthly Bird Count at Hornsby Bend
Saturday, September 13, 7 a.m. and 4 p.m.

A Swift Night Out! – Multiple Chimney Swift Roosts Across Austin
Sunday, September 14, 7 to 8 p.m.

Two-hour Tuesday! at St. Edwards Park, led by Ken Zaslow
Tuesday, September 16, 7:30 to 9:30 a.m.

Copperfield Nature Trail
Saturday September 20, 8 a.m. to 11 p.m.

Hornsby Bend Monthly Bird Walk
Saturday, September 20, 7:30 to 11 a.m.

Native Plant Walk with Diane Sherrill
Sunday, September 21, 8 a.m.

Super-Tuesday! at Commons Ford Ranch Park, led by Deb and Lee Wallace
Tuesday, September 23, 7 to 10:30 a.m.

Balcones Canyonlands/Water Quality Preserves – Part I
Friday, September 26, 7:30 to 10:30 a.m.

Commons Ford Monthly Bird Walk with Ed Fair
Saturday, September 27, 7 to 11:30 a.m.

Super Tuesday! at Palmetto State Park, led by Terry Banks
Tuesday, September 30, 6 a.m. to early afternoon

Compiled by Travis Audubon volunteers Jane Tillman and Raeanne Martinez


A one-in-a-million weather photo

September 9th, 2014 at 1:42 pm by under Weather

Weather photographer Brian Miner took one of the most beautiful photos we’ve seen in a long time last week. Details from Climate CentralIn it, the arc of the rainbow stretches across a verdant field behind a squall line in Kansas. Miner saw the rainbow after he had moved to the back of the lines of storms to avoid hail. He backed into a driveway for a barn, set up his camera, wrapping it in a rain poncho, and then sat under the hatch of his SUV, he told Climate Central. Serendipitously, at the moment Miner took the photo, lightning — which he said was everywhere in the area — shot out from the storm clouds, almost appearing to emanate from the rainbow itself. Truly awesome.

Weather photographer Brian Miner snapped this image in Kansas after a squall line blew through but while it was still producing lightning.
Click image to enlarge. Credit: Brian Miner


Western drought drops Lake Mead to lowest level since it was built

September 5th, 2014 at 1:30 pm by under Weather

On July 11, the day these photos were taken, the Lake Mead reservoir reached its lowest water level since the lake was first filled during the construction of the Hoover Dam in the 1930s, according to the Bureau of Reclamation. The lake’s elevation was 1,081.77 feet—147.23 feet below capacity and 133.99 feet below its last peak in 1998. Similar to how the rings in the cross-section of a tree trunk can tell a story about that tree’s past, the high points and low points of Lake Mead’s water history can be glimpsed from observing recent photos taken at the Hoover Dam.

The highest rust-colored ring on the concrete dam structure shown in the top photo marks the height of the water when the lake is near capacity (it’s never allowed to literally fill to the tip-top).  The top of the dark ring around the water intake towers at image left in the foreground indicates the height of the water level on December 21, 2012—the highest the lake has been this decade. At the time, water levels were down 95.4 feet from 1998 levels. The white “bathtub ring” seen on the rocky sides of the reservoir in the bottom photo shows the historical high water level in the reservoir. The ring is a coating of minerals, deposited on the rocks while they were covered by water.

The Lake Mead reservoir—the largest in the United States—stores Colorado River water for delivery to farms, homes, and businesses in southern Nevada, Arizona, southern California, and northern Mexico. According to the National Park Service website, about 96 percent of the water in Lake Mead is from melted snow that fell in Colorado, Utah, New Mexico, and Wyoming. Each year, these “Upper Basin” states are required to allow a minimum flow of Colorado River water to reach Lake Mead.

This year’s new low was hardly unexpected. Runoff in the Upper Colorado River Basin was 94 percent of average in 2014, but that flow wasn’t enough to make up for the previous two years’ shortfalls: runoff was only 47 percent of normal in 2013 and 45 percent in 2012, according to the Bureau of Reclamation.

The past two years are a continuation of a15-year dry spell in the U.S. Southwest that has led to more water going out of Lake Mead than coming in. The lake reached an all-time high of 1,215.76 feet in November 1998, but it has not approached that level since. The Bureau’s Boulder Canyon Operations Office projects the lake’s elevation to continue to drop through the fall, falling to approximately 1,080 feet in November of this year.

Fluctuations in regional climate and the resulting water level in Lake Mead are an expected part of its operation, but many scientists are concerned that the recent prolonged drought could be a sign that the region will confront significant water supply challenges as greenhouse gas concentrations continue to rise.

Projections of precipitation changes in the Colorado watershed are less certain than those for temperature changes in the Southwest, but rising temperature along with declining snowpack and streamflows may threaten the reliability of surface water supply across the Southwest, according to the 2014 National Climate Assessment.

The report also warns that the current drought could be just beginning. Southwest paleoclimate records show that severe mega-droughts at least 50 years long have occurred in the past several thousand years. Unlike those ancient droughts, however, similarly dry periods in the future are projected to be substantially hotter, and for major river basins such as the Colorado River Basin, drought is projected to become more frequent, intense, and longer lasting than in the historical record.


Drought severe to exceptional across much of Central Texas

September 4th, 2014 at 3:55 pm by under Weather
Drought Monitor
DROUGHT INFORMATION STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1245 PM CDT THU SEP 4 2014

...DROUGHT CONDITIONS REMAIN THE SAME OVER THE PAST WEEK...
SYNOPSIS...
AFTER AN AUGUST THAT FEATURED SPORADIC RAINFALL...SEPTEMBER HAS SEEN
SPOTTY RAINFALL WITH THE MAJORITY OF RAIN FALLING ACROSS THE
SOUTHERN AND SOUTHEASTERN PORTIONS OF THE REGION. MOST
RIVERS...CREEKS AND STREAMS CONTINUED TO SHOW DECREASING FLOWS
ESPECIALLY IN LOCATIONS THAT HAVE MISSED THE RECENT RAINFALL. THE
MAJORITY OF SOUTH CENTRAL TEXAS WAS REPORTING BELOW AVERAGE STREAM
FLOWS WHILE THE EASTERN HALF REPORTED BELOW TO MUCH BELOW AVERAGE
FLOWS.  (more...)

Southwest may face ‘megadrought’ this century

August 28th, 2014 at 5:41 pm by under Weather

Megadrought risk

Due to global warming, scientists say, the chances of the southwestern United States experiencing a decade long drought is at least 50 percent, and the chances of a “megadrought” – one that lasts over 30 years – ranges from 20 to 50 percent over the next century.

The study by Cornell University, University of Arizona and U.S. Geological Survey researchers will be published in a forthcoming issue of the American Meteorological Society’s Journal of Climate.

“For the southwestern U.S., I’m not optimistic about avoiding real megadroughts,” said Toby Ault, Cornell assistant professor of earth and atmospheric sciences and lead author of the paper. “As we add greenhouse gases into the atmosphere – and we haven’t put the brakes on stopping this – we are weighting the dice for megadrought conditions.”

As of mid-August, most of California sits in a D4 “exceptional drought,” which is in the most severe category. Oregon, Arizona, New Mexico, Oklahoma and Texas also loiter between moderate and exceptional drought. Ault says climatologists don’t know whether the severe western and southwestern drought will continue, but he said, “With ongoing climate change, this is a glimpse of things to come. It’s a preview of our future.”

Ault said that the West and Southwest must look for mitigation strategies to cope with looming long-drought scenarios. “This will be worse than anything seen during the last 2,000 years and would pose unprecedented challenges to water resources in the region,” he said.

In computer models, while California, Arizona and New Mexico will likely face drought, the researchers show the chances for drought in parts of Washington, Montana and Idaho may decrease.

Beyond the United States, southern Africa, Australia and the Amazon basin are also vulnerable to the possibility of a megadrought. With increases in temperatures, drought severity will likely worsen, “implying that our results should be viewed as conservative,” the study reports.

“These results help us take the long view of future drought risk in the Southwest – and the picture is not pretty. We hope this opens up new discussions about how to best use and conserve the precious water that we have,” said Julia Cole, UA professor of geosciences and of atmospheric sciences.

The study, “Assessing the Risk of Persistent Drought Using Climate Model Simulations and Paleoclimate Data,” was also co-authored by Julia E. Cole, David M. Meko and Jonathan T. Overpeck of University of Arizona; and Gregory T. Pederson of the U.S. Geological Survey.

The National Science Foundation, National Center for Atmospheric Research, the U.S. Geological Survey and the National Oceanic and Atmospheric Administration funded the research.


Epic drought in West is literally moving mountains

August 26th, 2014 at 1:14 pm by under Weather

(Climate Central)

Climate change is driving the Greenland Ice Sheet to melt, which is contributing to sea level rise. But imagine that the same amount of water melting from Greenland each year is being lost in California and the rest of the West because of the epic drought there.

What happens? The land in the West begins to rise.

In fact, some parts of California’s mountains have been uplifted as much as 15 millimeters (about 0.6 inches) in the past 18 months because the massive amount of water lost in the drought is no longer weighing down the land, causing it to rise a bit like an uncoiled spring, a new study shows.


Death Valley, Calif.
Credit: QQ Li/flickr

For the first time, scientists are now able to measure how much surface and groundwater is lost during droughts by measuring how much the land rises as it dries. Those are the conclusions of the new study published Aug. 21 in the journal Science by researchers at the Scripps Institution of Oceanography at the the University of California-San Diego.

The drought that is devastating California and much of the West has dried the region so much that 240 gigatons worth of surface and groundwater have been lost, roughly the equivalent to a 3.9-inch layer of water over the entire West, or the annual loss of mass from the Greenland Ice Sheet, according to the study.

While some of California’s mountains have risen by about 0.6 inches since early 2013, the West overall has risen by an average of about 0.157 inches.

“Groundwater is a load on the Earth’s crust,” said Klaus Jacob, a seismologist at Columbia University’s Lamont-Doherty Earth Observatory in Palisades, N.Y., who is unaffiliated with the study. “A load compresses the crust elastically, hence it subsides. When you take that load away (by the drought) the crust decompresses and the surface rises. From the amount of rising, one can estimate the amount of the water deficit.”

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The drought-related uplifting was discovered when researchers were analyzing data from GPS stations within the National Science Foundation’s Plate Boundary Observatory. One researcher noticed that all of the GPS stations moved upward since 2003, coinciding with the timing of the current drought.

But most of the movement occurred since last year as the West’s drought has become more and more extreme, said Duncan Agnew, a professor at the Institute of Geophysics and Planetary Physics at the Scripps Institution of Oceanography at UC-San Diego, and a study co-author.

“The implications of this have yet to play out,” Agnew said. “What we’ve shown is that there is a measurement technique we can use to get a total water loss — water loss in places where we have no direct measurements.”

Low levels on Lake Mead, a major source of water in California.
Credit: Raquel Baranow/flickr

He said such uplifting likely occurs in every drought, but it has never been observed before because scientists did not have the tools to detect the uplifting until now.

“That’s why this study is interesting,” Agnew said. “We can use this set of tools, which were installed for a different purpose in order to monitor water changes.”

He said the uplifting likely has no significant effect on earthquake potential in California and elsewhere even though loss of ground and surface water has added stress to major faults in the region.

“The total amount of stress that’s been added in the last 18 months from drought is the same amount of stress that’s added every week because of plate techtonics,” he said.

Jacob said the study shows that the changes in the elevation of the landscape and the stress on faults are so small the effect will be extremely minor.

But, Jacob said, the significance of the study is that it shows a new way for scientists to estimate total water loss during times of drought, which would be more difficult to estimate without being able to detect how much the land is being uplifted in dry years.


Drought forecast to improve or end by December

August 21st, 2014 at 4:11 pm by under Weather

There is good news today from the Climate Prediction Center about the future of our drought. The U.S. Seasonal Drought Outlook for the period August 21 through November 30 indicates and end to drought conditions for much of Central Texas, with drought improvement elsewhere.

This can be attributed to several factors (discussion below), including the expectation of a developing El Niño pattern in the Pacific Ocean, which often increases rainfall across Texas in the fall and winter.

8-21 Seasonal drought outlook

Discussion for the Seasonal Drought Outlook

Tools used in the U.S. Seasonal Drought Outlook (SDO) included the official Climate Prediction Center (CPC) temperature and precipitation outlooks for September 2014 and September-November 2014, various short- and medium-range forecasts and models such as the forecast 5-day and 7-day precipitation totals from the Weather Prediction Center (WPC), the 6-10 day and 8-14 day CPC forecasts, the NAEFS precipitation outlooks, the soil moisture tools based on the Constructed Analog on Soil Moisture (CAS), dynamical models (CFSv2, NMME, IRI, and IMME), the 384-hour total precipitation forecasts from several runs of the GFS, the four-month Palmer drought termination and amelioration probabilities, climatology, and initial conditions. An El Niño Watch is currently in effect, with the August 18 ENSO update indicating about a 65% chance of El Niño during the fall and early winter.

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