Overview
June was a little on the warm side and a little on the dry side, in general. But dryland farmers in central and northeast Oregon rejoiced because of abundant rains, at a very opportune time. June rains often “make it or break it” for growers east of the Cascades, and after several years with dry periods at this time of year, the farmers and ranchers were especially grateful.
Table 1 is a summary of monthly
averages and totals at selected stations throughout the state. Table 2 lists
daily temperatures and precipitation for most of the locations listed in Table
1. In Table 3, monthly and
seasonal precipitation totals throughout the state are listed. Figure
1 shows
the percentage of seasonal precipitation statewide.
Basin Summary
Here is a summary of precipitation, water supply, and snow pack as of the end of the month, by river basin:
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| BASIN |
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| OWYHEE | 63 | 73 | 100 | 33 | 63 | -1.2 |
| MALHEUR | 115 | 96 | 102 | 36 | 37 | -0.3 |
| GRAND RONDE, POWDER, BURNT | 93 | 112 | 101 | 94 | 85 | -1.1 |
| UMATILLA, WALLA WALLA, WILLOW | 125 | 110 | 108 | 164 | 114 | 1.4 |
| UPPER JOHN DAY | 64 | 109 | 100 | 106 | 90 | 0.2 |
| UPPER DESCHUTES, CROOKED | 141 | 110 | 95 | 47 | 58 | 0.0 |
| LOWER DESCHUTES, HOOD RIVER | 129 | 98 | 91 | 88 | 75 | -0.8 |
| WILLAMETTE | 87 | 93 | 93 | 95 | 84 | -0.3 |
| ROGUE, UMPQUA | 67 | 99 | 94 | 94 | 82 | 0.2 |
| KLAMATH | 74 | 97 | 92 | 48 | 63 | -2.0 |
| LAKE COUNTY, GOOSE LAKE | 72 | 90 | 85 | 42 | 60 | -0.5 |
| HARNEY | 58 | 81 | 102 | 79 | 74 | -0.5 |
| NORTH COAST | 87 | 90 | n.a | 33 | 63 | -0.8 |
| SOUTH COAST | 77 | 95 | n.a | 36 | 37 | -2.1 |
Forecasts
The Climate Prediction Center’s (CPC) forecasts for July-September appear
below. Temperatures for all of Oregon are likely to be above normal. Precipitation
probabilities suggest an increased chance of below-normal precipitation. CPC
also says:
“
Most climate models … indicate continuation of near-neutral tropical
SSTs at least through the summer...after which the spread among model forecasts
increases. The majority of models favor positive SST anomalies in the Niño
3.4 region by the upcoming cold season...but the magnitude of the anomalies
are not enough to satisfy the criteria for an El Niño in many cases
and even the models with the largest anomalies are not forecasting a strong
El Niño.
“ The forecasts for July-Sept and Aug-Oct 2004 favor above normal temperatures over much of the west and southwest ... a region of abnormal dryness is likely during July-Sept over the Northwest U.S.from Washington and Oregon eastward and southeastward to include parts of the Great Basin and northern Rockies during July-Sept.”
Oregon Climate Service predicts near-normal temperatures and precipitation
for July. For the three-month period July-September we predict normal temperatures
and below-normal precipitation.
Drought in the West
May 30, 2004
Here in Oregon we’ve dodged a bullet the last several years. Unfortunately,
some of our neighbors have been hit hard.
The last seven years have seen mostly drier than average conditions in the
Western U.S., particularly the Southwest. The same climate shift that brought
lots of rain, snow, and enhanced salmon runs to the Northwest has done just
the opposite in Arizona, New Mexico, Utah, Wyoming, and parts of the remaining
western states. According to a recent NASA press release (see reference below),
“
Drought has gripped some parts of the West for as many as seven consecutive
years, causing one of the worst dry spells in decades. Soils are dry; reservoirs
are low. Farmers and golf course managers are vying for irrigation water, residents
face water rationing measures, and the politics of water "seniority" rights
is heating up between cities and between states.”
My friend Roger Pielke, Sr., the Colorado State Climatologist, said this about
drought:
“In modern times "there's more to drought than simple lack of precipitation," adds
Roger Pielke Sr., a state climatologist for Colorado and a professor of atmospheric
sciences at Colorado State University. "You have to consider human factors
like the amount of water being drained from rivers for crop irrigation and
drinking water. In absolute terms, the ongoing dry spell is not yet as severe
as the Dust
Bowl of the 1930s, but the impacts have been relatively severe because the
demands that people place on the water supply are so much greater now than
they were
back then."
In the 30s, water supply recipients were primarily agriculture and domestic users.
Nowadays, in addition to supporting many more users due to increasing population
in the West, water suppliers have to worry about some additional types of demand:
1. Recreation. Reservoirs are very popular recreation sites, and the public demands
full reservoirs for boating and other recreation pursuits. At the same time,
rivers are popular for recreation, and there is demand to keep them flowing throughout
the summer.
2. “In-stream” uses. Salmon and other aquatic species suffer when
water levels are low. There is increasing pressure to keep rivers, streams
and lakes full (and cool) to protect these species.
3. Industry. Water is an essential ingredient for most manufacturing processes.
One of the primary issues regarding water supply in the West involves the
supply-demand process. In many areas, demands for water far exceed supply.
Take Los Angeles,
for example. This is a megalopolis in a semi-arid area whose water inputs (precipitation)
are far smaller than the demands. Thus, Los Angeles has had to import water
from other areas, some of them very far away. These include Northern California,
the
Colorado River and (in years past) Owens Valley and Mono Lake. But increasing
demands in other states have led to some reallocations of water. One likely
victim will be the farming community of Imperial Valley, one of California’s
most productive agricultural areas. For decades, farmers there have relied
on Colorado
River water for irrigation. But that may change for many growers in the face
of likely cutbacks in Imperial Valley water supplies later this year.
Fortunately, Oregon has received sufficient precipitation to enable most water
users to have sufficient supply. While March and April were quite warm and
dry and led to some water supply worries, May has had near-normal precipitation
statewide,
with well above-average in parts of eastern Oregon. For example, Pendleton
has received 1.71 inches of rain through May 28, compared with a normal of
1.08.
Several eastern Oregon locations have received more than 3 inches this month.
And since many eastern Oregon farms practice “dryland farming,” particularly
for wheat, rains in May are very welcome indeed!
Nonetheless, let me reiterate what I say to Oregonians every summer, whether
we’re in a drought or not: water is and will continue to be a precious
resource, Use it wisely, and conserve where possible. As my late mother was fond
of saying: “Waste not, want not.”
NASA press release: http://science.nasa.gov/headlines/y2004/21may_drought.htm?list656723
Drought Monitor: http://www.drought.unl.edu/dm/monitor.html
Blue Moon
Blue Moon, you saw me standing alone
Without a dream in my heart
Without a love of my own.
“Blue Moon,” by Lorenz Hart and Richard
Rodgers
“Blue Moons” don’t happen often, but we’re in for one
this month. By definition, Blue Moon is the second full moon in a calendar month.
Most months have only one full moon, but once in awhile (“once in a blue
moon”) a second one occurs. Since the lunar cycle is 29 days, but most
months have 30 or 31 days, so it is possible to have two full moons in a single
month. This occurs on average once every two and a half years.
July has already had one full moon (July 2nd), so the next one, on July 31st,
qualifies as a Blue Moon. Of course, the moon won’t really be BLUE. But
from time to time the moon has taken on very different colors, even blue.
In 1883, for example, Krakatoa, a volcano in Indonesia, exploded violently. The
sound was heard several thousand miles away. Ocean waves created by the blast
were detected in the English Channel. And ash rose to the upper levels of the
atmosphere. The moon turned blue.
Some of the ash particles were just the right size to scatter red light, while
allowing other colors, such as blue and green, to pass through. White light
from the moon emerged from the clouds as blue (and sometimes green). The blue
moons
lasted for years after the eruption. Some people reported lavender suns and "such
vivid red sunsets that fire engines were called out in New York, Poughkeepsie,
and New Haven to quench the apparent conflagration," according to vulcanologist
Scott Rowland at the University of Hawaii. NASA’s web site has an interesting
article describing this (that’s where I found Rowland’s quote):
http://science.nasa.gov/headlines/y2004/07jul_bluemoon.htm?list656723
Other volcanoes, though less significant than Krakatoa, have also turned the
moon blue. This includes the 1980 eruption of nearby Mt. St. Helens. The 1991
Pinatubo eruption was the most recent, and you may remember the colorful sunrises
and sunsets that lasted for many months.
A somewhat similar light scattering phenomenon occurs in association with
severe storms in the Midwest and Eastern U.S. This is the legendary “green sky,” which
causes great concern among many sky watchers – or, in some cases, excitement!
Not every green sky portends severe weather, and not every sever storm is preceded
by green sky, but the two happen often enough that folklore suggests “green
skies precede tornadoes.” This phenomenon is rather mysterious, but many
scientists believe that water vapor in the air causes enough light scattering
to remove all but the green.
More common though, is red sky (as in “red sky in morning, sailor take
warning”). This occurs most often near sunrise and sunset, as the sun shines
at an angle though the atmosphere. At these times, the sun’s path is very
long (think about looking almost horizontally through a swimming pool, versus
looking straight down; in the latter case, you’re looking through much
less water). Blue and green light are scattered more effectively by air molecules,
and during their long transit of the atmosphere they are removed, leaving only
the red. Thus, red sunrises and sunsets! And the same effect causes the moon
to appear red when it’s near the horizon. So if you see the moon rise in
the evening on July 31, you’ll be watching a “Red Blue Moon.”
Oregon Climate Service
George H. Taylor, Oregon State Climatologist
Wayne P. Gibson, Programmer/GIS mngr.
Mandy Matzke, Research Assistant/Manager of Data Services
Melanie Mitchell, Undergraduate Assistant
Wolf Read, Undergraduate Assistant
Emily Gibson, Student Assistant
Cadee Hale, Publications Assistant
Kelsey Kuykendall, Undergraduate Assistant
Sara Joos, Student Assistant
Oregon Climate Service, Strand 326,Phone: (541) 737-5705 Oregon State University Fax: (541) 737-5710 Corvallis, Oregon 97331 E-mail: oregon@coas.orst.edu Web: http://www.ocs.oregonstate.edu
