 Ask meteorologists to describe New Mexico's weather and they'll you it has a
semiarid, subtropical climate with abundant sunshine, gusty
winds, little
rainfall, and low humidity.
Ask farmers and ranchers to describe the weather,
and they tell you about droughts that parched range grasses and dryland crops,
hailstorms that flattened a promising year, rains that ruined cut alfalfa,
frosts that zapped fruit, winds that sandblasted vegetables, and cold snaps that
killed sheep and cattle. Their highest compliment about the weather is, "It
wasn't bad."
Whether you see it in scientific terms or watch its effects on a particular
crop, New Mexico's weather is variable and extreme. National Weather Service (NWS)
records show temperature extremes ranging from -50 to 122 degrees. In a single
day, temperature swings of 30 to 40 degrees are commonplace.
Though rain is scant, New Mexico has more than its share of severe weather,
including thunderstorms, flash floods, hail, lightning strikes, high
winds, and
tornadoes. Annual snowfall can vary from less than two inches to 20 of inches.
"For what many people see as a 'no weather' place, we seem to have quite a
bit," notes Keith Hayes, warning coordination meteorologist with the NWS in
Albuquerque. During one weekend this spring, Hayes tracked a
blizzard in
east-central New Mexico; a dust storm with 80-mile-per-hour winds in Deming; and
a severe weather system with thunderstorms, hail, and tornadoes in Eddy County.
The unpredictability of New Mexico's weather keeps forecasters guessing and
producers watching the skies, the weather updates, and the long-term outlooks.
Each year, farmers and ranchers do battle with the elements.
Sun: Measuring an enchanted acre of sunlight
Sunshine makes up the biggest weather commodity in New Mexico, fitting for a
state with the ancient Zia sun symbol on its flag. The flag's gold field
represents Spanish conquistadors' quest for the Seven Cities of Gold. While the
dreams of precious metal never panned out, the state is renowned for its golden
sunlight.Tourism promoters brag about the percentage of sunny days in the
Land of Enchantment, second only to Arizona, according to data from the Commerce
Department and National Oceanic and Atmospheric Administration.
Farmers measure the value of an acre of enchanted sunlight in more
down-to-earth terms. Soil temperature is key for optimum planting. Sunshine
promotes germination and strengthens tender seedlings.
Converted to heat units and degree days, sunshine affects crop maturity and
helps predict when insect populations will peak. Along with wind, sunshine
determines the potential evapotranspiration rate used to figure crop water needs
and schedule irrigation.
"Year-round sunshine is our biggest advantage," says Rhett Dodge, a 1996 NMSU
graduate who's spent time in cloudy Oregon and Canada and now works for
Aldershot of New Mexico, a wholesale nursery in Las Cruces.
While it's usually welcome, the enchanted sun can sometimes be too much of a
good thing.
The state's altitude increases ultraviolet radiation -- the so-called
"sunburn factor." Invisible UV rays increase by 4 percent for every 1,000 feet
above sea level.
Though they aren't a problem for most crops, UV rays can burn people in
minutes and scorch some tender plants.
Even on New Mexico's hottest days, plants, animals, and people get a break after
the sun goes down. Temperatures drop rapidly, thanks to the elevation and low
humidity. A major advantage of "dry heat" is less water vapor in the air to slow
down the nightly cooling process.
Wind: Driving windmills and weather
The opening verse of the state song, "O Fair New Mexico," paints a rosy picture
of the state's weather:
Under a sky of azure, where balmy breezes blow;
Kissed by the golden sunshine, is Nuevo Mejico.
Growing up, Parker experienced the drought of the 1950s and modified the song's
chorus: "O Fair New Mexico, it never rains, it never snows. The dadburn wind
just blows and blows."Wind blows because of differences in atmospheric
pressure, triggering air movement that equalizes the pressure.
On any day in eastern New Mexico, odds are the wind will be blowing. As an
extension of the Great Plains, the region lacks the buffering spine of central
mountains to deflect wind and storms. Meteorologists say that's why the High
Plains has more than its share of wind, hail, and severe weather.
Not surprisingly, six of the nation's 10 windiest cities are in the West.
Amarillo, Texas, adjacent to dust-storm-prone eastern New Mexico, gusted into
third place behind Blue Hill, Mass., and Dodge City, Kan.
Mountains, a source of "instant weather," attract fast-moving, upper-level
storms that bring high winds.
The number of windmills in New Mexico testifies to the wind's power to shape
our landscape and lives.
"Some of the windmills have been out there for three or four generations,"
says James Dean, a retired NMSU agricultural mechanics professor who teaches
classes on windmill maintenance.
Although it seems an ever-present force, New Mexico's wind is not always
reliable. "It's a very dependable source of power for lifting water . . . so
long as the wind blows," Dean jokes.
To compensate, ranchers fill huge water storage tanks, rotate animals into
areas with water, and install solar-powered submersible pumps or gasoline-driven
pump jacks as backup power.
When the wind blows, it often picks up soil, sandblasting crops. The tattered
leaves of wind damage resemble the early stages of many diseases, leading
Natalie Goldberg, Extension plant pathologist, to ask about wind when she
receives plant specimens.
Though it's the bane of vegetables, wind can be a friend to fruit. Some
growers head off freezes by stirring up artificial gusts with giant propellers.
"For orchards in valleys, the wind machines keep cold air from settling," says
Esteban Herrera, Extension horticulturist. "This inverts the layers of cold and
warm air, protecting the trees in bloom."
Rain: Counting on the monsoon season
Wind is a powerful force in New Mexico, not only for pumping water but also for
shaping the weather. One somewhat predictable event in New Mexico's weather is
"monsoon season" in July and August, when most of the rain falls in summer
thunderstorms.Though it may seem a stretch to talk about a monsoon in the
desert, the term actually has more to do with wind than rain, Blood says.
"When you grow up, in school you learn about the monsoon season when they
have tremendous rains in India," he says. "But monsoon does not refer to rain
per se, but to the reversal of flow that brings an increase in moisture."
When the wind changes direction during monsoon season, it sets up a southerly
flow of moist air, which condenses over land and falls as rain. In New Mexico's
case, the monsoonal flow pulls up moist air from the Pacific Ocean and Gulf of
Mexico, triggering summer thunderstorms.
No matter how much rain a storm brings, it won't erase the ever-present
threat of a drought.
Though it's no laughing matter, the punch line to Extension farm management
specialist Jim Libbin's favorite weather joke makes the point: What did the New
Mexican say on the first dry day after 40 straight days of rain? "We're heading
into a drought."
This century, droughts have parched the state in the early 1900s, 1930s,
1950s, 1970s, and 1990s. For New Mexicans who have felt the effects of drought
firsthand, it's no comfort to hear that the last 200 years may have been the
wettest period in 1,500 years. Researchers with California State University drew
that conclusion after examining 2,000 years of tree ring evidence from New
Mexico.
Whatever the case, John Fowler, coordinator of NMSU's Range Improvement Task
Force, still remembers the best drought advice he heard from an old-timer nearly
20 years ago.
"He told me that unless you're born in the Southwest, you can't ranch here
because you don't understand the power of drought," Fowler recalls. "To survive,
New Mexico ranchers have to manage as if every year will be a drought. You bet
on drought, you use low to moderate stocking rates, and you have financial
reserves if you're in it for the long run."
Even after the rains come, it may take years for ranchers to recover
financially and to rehabilitate rangeland. In a drought, perennial grasses lose
ground to annuals, shrubs encroach, and noxious weeds gain a toehold, Fowler
says.
Just as important as how much rain comes is when and how it falls. Averaging
covers up many extremes. The first half of the year may be one of the driest
ever, only to be followed by record-setting rainfall in the last half. Several
inches can fall in a four-hour flash flood or dribble out in quarter-inch
showers throughout the month.
Farmers with surface water allotments generally prefer the predictability of
scheduling their irrigation.
Though it won't ever set records for total rainfall, New Mexico has the
highest number of lightning injuries and fatalities per capita.
The reason is that in wetter climates, rain drives people indoors, where
they're protected from lightning, says Hayes, the warning coordination
meteorologist.
"What happens here is that people feel a few raindrops, but they don't stop
the little league game or the round of golf or the hike along the top of the
ridge," he says. "That's why more people get hurt." Dry lightning storms, in
which rain evaporates without ever reaching the ground, can start devastating
range and forest fires.
Cold snaps: Surviving a roller coaster spring
One way to visualize New Mexico's weather is to slice the state into growing
zones based on the number of frost-free days and last frost dates. Divided this
way, the state has three diagonal bands that run from southwest to northeast.All of this neat mapping falls apart every spring in the face of notoriously
unpredictable cold snaps.
Storms during calving time take a toll on beef cattle herds, particularly if
they follow a drought that has weakened animals.
Bad weather also can harm newly imported stocker cattle before they have had
time to acclimate.
Roller coaster temperatures damage plants as well. Tricked by warm days,
trees come out of dormancy and start growing, only to be frozen back by a cold
snap. "It's so common, it's called Southwest injury," Goldberg says.
Except for agreeing that they don't like drought and hailstorms, it would be
hard to reach a consensus on the perfect weather. The same grower may even want
different conditions for each crop.
For farmers and ranchers, the struggle with the elements starts again each
season. Given the state's changeable weather, the only safe prediction is that
no two years will ever be the same in fair, sunny, windy, stormy New Mexico.
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