Two key factors influencing Anza-Borrego weather are elevation and exposure to
the Pacific weather patterns that move across southern California.
As storms move across the mountains that
surround Borrego Springs, the air is forced upward, where it cools, water
condenses, and precipitation falls as rain or snow. It very common to see
snow on the mountain peaks in Borrego during the late fall, winter, and early spring.
Having dropped most of their moisture in the mountains these weather patterns
are relatively dry by the time they blow over the lowlands of the desert, an
effect that is known as a rain shadow. Many of the large world's
desert are created by this same effect.
Elevations in Anza-Borrego Desert State Park range from near sea level, in
the eastern areas closest to the Salton Sea, to over 6200 feet in the mountains.
Within Anza-Borrego, very slight differences in temperature and average annual rainfall have created countless life zones, where the plants and animals
have adapted to the unique condition conditions found in that zone.
Data from the National Weather Service, show just how
different things can be in different parts of Anza-Borrego. The town of Borrego Springs, elevation 597 feet
is just 15 miles from the community of Ranchita, at an elevation of 4065 feet.
TOWN OF BORREGO SPRINGS, AT 597 FEET, IS KNOWN FOR IT'S
AND WARM WINTER WEATHER.
BUT WINTER SNOW
IS COMMON IN THE MOUNTAINS THAT SURROUND BORREGO SPRINGS.
These two locations in Anza-Borrego give a glimpse of the sharp differences
in climate between high and low elevations.
Historical Weather Information For Borrego Springs - Elevation 597
Borrego Average 6.18
inches per year
mean temp 72.7°
Historical Weather Information For Ranchita - Elevation 4056
Ranchita Average 33.66
inches per year
Average Monthly Mean Temp: 52.9°
Although desert flash floods can occur at any time of year they are most common in
Anza-Borrego during the late summer months when powerful thunderstorms can drop
large amounts of rain in a short period of time, sometimes at a rate of several
inches per hour. The soil is unable to absorb the water at the rate it is
falling so most of the water runs across the surface.
The lack of vegetative cover in the desert allows the water to gather momentum
and the washes or canyons where it accumulates can become raging torrents in a
very short period of time. The land does not need to be steep for flash floods
to occur, large gently sloping areas can also accumulate large amounts of water.
Desert flash floods can quickly cut through the earth in one place, dislodging
sand, rocks, boulders, and trees, and then depositing them many miles from their
Flash floods are particularly dangerous because it is very difficult to predict
exactly when and where they may take place. The longevity of the flood may be
very short but they can quickly create a raging river where a dry wash existed
only moments before.
Flash Flood Safety
These photos show what happened to a pickup in late July
2012 in the Fish Creek area when a flash flood struck. The owner of the
pickup and his son went out to hike to the wind caves. When the water
started flowing, there was no time to move the pickup, but dad and his son
were able to make it to higher ground and were not harmed. But
the pickup was pushed well over a mile down the wash before it came to rest.
This is what was left of it. -- Photos by Thomas Teske
The following are general flood safety
rules that could help in keeping you out of danger:
Keep an eye on the weather. If the weather is questionable don't go into
areas that are susceptible to flash flooding. The National Weather Service
will often issue flash flood advisories for widespread areas. Floods can occur
many miles from the rainfall so the only safe option is to stay out of areas
that are prone to flooding, particularly remote areas.
If you are caught unaware, move to higher ground immediately.
If you are driving, never try to drive through a flash flood. The force of
the water can be extreme. According to FEMA, many passenger cars will loose
control and stall in just six inches of water. A foot of water will float many
vehicles. Two feet of water will carry most vehicles away, including SUVs.
Never enter a flooded road or wash. The depth of the water can be deceiving.
Flash floods are the number one cause of weather related deaths in the United
States. The majority of people killed by flash floods in the United States are
killed in vehicles that are swept away by the force of the water.