As tropical storm BUD spins it’s way north in the Sea of Cortez it’s copious moisture is being drawn into the desert southwest by a large low-pressure trough originating in the Pacific northwest. The trough’s counter clockwise spin is drawing in BUD’s energy and up to 1.3″ precipitable water has been measured. When the disturbance moves into the San Juan later tonight and tomorrow we could see some good rains, lightning and flash flooding near the Durango burn areas. Might get ugly if all this activity works in syncronicity.
Some satellite photos and vorticity/ precipitation maps below.
A big world view of BUD in southern Sea of Cortez about noon MST with the low pressure trough drawing it’s moisture into the desert SW.
Precip map at 12Z today
Vorticity (measured instability of a vertical air mass), showing the low dropping down from the Pacific NW into southern Cal and the Great Basin today at 12Z. See BUD (yellow & red) at the bottom over southern Baja California.
just reporting in from a wet and windy southern baja. rains started about 3 am last night and the winds started in earnest this morning shortly after dawn and have been increasing thru the day – i think they are calling it steady 45-50 with gusts, seems about right.
hope you get some moisture out of this system – sounds like its on track for that.
here’s a couple of photos from this morning. this is what the ‘beaches’ are looking like
Could this be the beginning of the monsoon? Of course the onset of the monsoon is a dangerous time with lightning often preceding the rains. Let’s hope we get some nice female rains.
Do whatever you as Masters need to do to make it happen. Ellen and I will deploy our garden prayer flags.
Joe riding monsoon season in Grand Junction
National Weather Service forecaster Jeff Colton called for several more dry, hot days across Southwest Colorado. The soonest possibility for rain will be Wednesday. Summer monsoons typically begin mid-July but could begin sooner this summer, perhaps the last week of June, based on La Niña weather patterns, he said.
Almost every tract of land in the contiguous United States was warmer than normal in May, helping to break a Dust Bowl-era record.
The month’s average temperature 0f 65.4 degrees swept by the previous high mark of 64.7 degrees set in 1934. Temperatures were more than 5 degrees above normal, according to the National Oceanic and Atmospheric Administration, which published a May U.S. climate assessment Wednesday.
The 1934 record was impressive, enduring for decades even as the climate has warmed because of increasing greenhouse gases in the atmosphere. One of the main reasons May 1934 was so hot was because it was so dry, posting the least precipitation for the month on record. When the land surface is dry, it heats up faster.
A combination of drought and farming practices had left fields bare of vegetation in 1934, resulting in “an estimated 35 million acres of formerly cultivated land had been rendered useless for farming,” according to History.com.
The parched conditions were so severe that on May 11 “a massive dust storm two miles high traveled 2,000 miles to the East Coast, blotting out monuments such as the Statue of Liberty and the U.S. Capitol,” History.com wrote.
In May 2018, temperatures soared to record levels even without as much help from dry soils. Precipitation was a hair above normal averaged over the nation. Maryland, hit by major floods in Frederick and Ellicott City, had its wettest May on record. So did Florida. Asheville, N.C., posted 14.68 inches of rain, its wettest month in history.
Spring is a tough time for long range outlooks. The westerlies are retreating northward. and the subtropical moisture is still languishing way south in the lower latitudes. It makes sense that May-June is our driest time of the year. When the monsoon moisture will arrive is near impossible to predict at this point. Though as I have theorized before, low snowpack tends to lead to warmer early-summer temperatures which helps pull the moisture into the region earlier. Let’s hope so. This could be a bad fire season for the desert SW including southern Colorado where snowpack is going downhill fast. Upper Colorado Region Snow Pack Condition Map
The longer outlook is for a tilt of odds towards warm and wet for May, then warm and dry for May-June-July. Seasonal Outlooks.
La Nina is as good as dead, with the temperatures in the Nino 3.4 region exactly at “normal” (attached pic 1). Looking into next cold season, the highest odds are for El Nino (attached pic 2) which favors the Four Corners with winter precipitation.
This past winter snow total & SWE (snow/water equivalent) on Red Mountain Pass. was 191”/15.3” The winter of 2017-18 was the fourth worst season in 75 years of records…76-77, 53-54, 01-02 were worse. 1980-81 season data is temporarily missing so that year needs to be revisited because it was absolutely awful … and could change the above statement. rōbert
Jeff Derry, director of the Colorado-based Center for Snow and Avalanche Studies, digs a snow pit at the Swamp Angel monitoring site in the San Juan Mountains.
A menace lurks beneath the snow high up in the southern Rocky Mountains: Dust. Lots and lots of dust.
This dust speeds up spring water runoff, causing intense melting and streams to peak weeks earlier than usual — which wrecks havoc throughout the alpine ecosystem. Water managers and fire forecasters alike are sounding the alarm about the consequences of less water flowing in streams and reservoirs.
At first glance the dust seems innocuous. How could something so simple undermine water infrastructure, stress wildlife and lengthen the wildfire season all at once?
For most of the winter, dust stays buried under blankets of snow. Then, as the days grow longer and the sun’s rays begin to melt the top layers, it begins to show. To see the dust before this happens, you need to dig a snow pit.
In the spring, Jeff Derry can often be found waist-deep in one of these pits, somewhere in the southern Rocky Mountains. Derry, the director of the Center for Snow and Avalanche Studies in Silverton, Colo., pays close attention to the amount of dust that winds up embedded in snow.
“I’ll be curious if you’re going to be able to see the dust event we had Feb. 18 and 19,” Derry said one day in April, shoveling snow over the edge of a half-formed pit. “It is very subtle.”
Derry uses a range of instruments to pull details from the pits, each fine-tuned to measure snow qualities such as temperature, density and reflectivity. But the best way to gauge the magnitude of a dust layer is with the human eye, Derry said.
White snow melts slower than snow covered in dust because of its high albedo, or reflectivity. It reflects radiation from the sun rather than absorb it.
Courtesy of the Center For Snow and Avalanche Studies
“It’s very qualitative in a sense,” he said. “You go out, you look for it, you dig, you see what you see.”
In Derry’s current cross-sectioned snowpack, about 7 inches down, is a beige-colored band of dust.
This tiny little strip of dust has the potential to upend how water is managed in the West. Eventually, Derry says, this snow will melt and empty into the Colorado River. Its watershed provides water for some 40 million people in the southwest.
When there’s no dust on the snow, it’s brilliantly white: On a sunny day, this kind of snow can be reflective enough to cause eye damage. Without dirt or dust, the snow melts off slow and steady — like the drumbeat of a drip from a faucet. Dust cases the snow gets darker and absorb more sunlight.
“It melts the snow faster than it would have otherwise,” Derry says. “And then it melts down to the next dust layer, and so on and so forth until all the dust layers have combined at the surface of the snowpack greatly reducing the [reflectivity].”
A thin, barely visible stripe of dust sits about 7 inches down in snowpack in Colorado’s San Juan mountains.
When these dust layers combine, the sun’s radiation quickens the pace of runoff, making it all that more difficult to capture and divvy up the precious water.
This quickened runoff makes managing water harder and upsets mountain ecosystems, causing earlier green up of vegetation. And when snow melts earlier, wildfires have more opportunity to spark and take hold.
Most of the dust that’s settling in places like the San Juan mountains comes from the desert southwest, from land disturbances like farming, oil and gas drilling, cattle grazing, recreation and residential development on the southern end of the Colorado Plateau.
“It’s kind of a slow crisis, a slow disaster,” said Rich Reynolds, an emeritus researcher with the U.S. Geological Survey in Denver. “It’s not like a hurricane. It’s not like an earthquake or a volcano.”
In the past 50 years, as the Sun Belt boomed, scientists recorded a dramatic rise in the amount of dust being deposited on snow — which forces fundamental changes in how spring runoff occurs. Reynolds says reversing this trend won’t be an easy task.
“There’s no one size fits all in terms of mitigation for these kinds of source areas,” he said. “Plus, these are large, large areas.”
In a 2010 study researcher, scientists found that in heavy dust years, the Colorado River’s flow on average peaked three weeks earlier than in years without heavy dust deposition.
The same study also found that earlier melting snow reduces the amount of water that runs to the Colorado River by about 5 percent. That’s more water lost than the entire state of Nevada uses from the river in a year.
“What we found looking at those two in this region, is that it was actually dust that controlled snowmelt timing and magnitude and sort of how fast snow ran out of the mountains, as opposed to temperature,” Skiles said. “We didn’t see any relationship to temperature at all.”
Warming temperatures are more likely to affect and diminish total snow accumulation, causing some snow to come down as rain. But when it comes to runoff, dust is the controlling factor. It’s the sun’s rays that force snow to melt, not outside air temperature.
While science is beginning to paint a clearer picture of how this phenomenon plays out, Skiles says that there’s plenty the field doesn’t know about dust.
“We still have some questions on what controls the actual dynamics of the dust events themselves,” she said. “We see dust in every year, but there’s a high variability between the amount of dust that’s deposited each year.”
Back in the San Juan mountains, Derry says he’s bracing for more dust events this spring. The mountain range has registered five dust events since October. Derry says the San Juans are ground zero for this problem. And because they’re a key part of an already overtaxed Colorado River system, he says everyone in the seven U.S. states and in Mexico that depend on the river should be concerned.
“We’re located at the headwaters of four major watersheds,” Derry says. “And our mountain systems are undergoing change at a fundamental level.”
Change that could make the West an increasingly dry — and dusty — place.
This story is part of a project covering the Colorado River, produced by KUNC and supported through a Walton Family Foundation grant.