Want to cook up a nice meteorological stew called “bombogenesis” (otherwise known as explosive growth of an extratropical cyclone)? Here’s the recipe:
Take a low pressure system mix in a big dollop of heat coming off the Gulf Stream. Now, move the developing storm into the North Atlantic where you’ve got relatively warm air to the southeast and frigid, polar air to the northwest. Stir…
The video above shows what you wind up with: Explosive growth of a cyclone in the North Atlantic. (Technically speaking, bombogenesis occurs when the central pressure of a storm drops 24 milibars in 24 hours or less, and that most definitely occurred here.)
SEE ALSO: ‘Weatherbomb’ Storm From 38,000 feet”
The video is based on infrared and water vapor data acquired by the Meteosat Second Generation on April 15 and 16. Called the “RGB Airmass” product, the data and the false-color scheme are designed to help meteorologists monitor the evolution of extratropical cyclones and jet streaks.
The cyclone in question develops toward the upper left corner of the frame, off the coast of Newfoundland in Canada. As the storm develops, it grows an eye-like feature.
Here’s another view, acquired by NASA’s Terra satellite on Thursday: Read More
Last week I shared a dramatic animation showing a massive sand storm sweeping across the Arabian Peninsula and across the sea to India and Pakistan.
Yesterday, the action shifted to the desert southwest of the United States: People from southern California to Utah experienced high winds and blowing dust — including the dust storm seen in the animation above. (To get your geographic bearings, click on the thumbnail at right.)
In terms of size, there was no comparison. Even so, winds gusting over 70 miles per hour and kicking up clouds of dust and sand caused mayhem on roads throughout the region. That included a 17-vehicle pileup on Interstate-80 in Tooele, Utah resulting in one fatality and at least 25 injuries. Read More
A green lightning bolt zapping a British habitation module on Mars?
Well, of course not. It’s actually a display of the aurora australis setting the winter sky on fire above the Halley Research Station in Antarctica.
The aurora australis is the Southern Hemisphere’s version of the aurora borealis. You can call them the “southern lights.”
The photo above is the second ‘postcard from Antarctica’ sent by Thomas Welsh, the station’s winter manager. I posted the first one on March 26. It includes photos, a summary of some of the research that’s done there, and a fascinating account of what it’s like to winter over on an Antarctic ice shelf, cut off from the rest of the world.
In his email to me this morning, Tom was short but sweet:
Here are some aurora photos, as promised. It was an incredible and very humbling display.
Humbling indeed: Read More
In its monthly update, the U.S. Climate Prediction Center today said the odds of El Niño continuing into Northern Hemisphere summer have increased to 70 percent.
This is up from 50 to 60 percent last month.
According to the report:
By the end of March 2015, weak El Niño conditions were reflected by above-average sea surface temperatures (SST) across the equatorial Pacific (Fig. 1), and by the expected tropical atmospheric response.
During an El Niño, trade winds ease, allowing warm surface waters in the tropical Pacific to move eastward, toward South America. This tends to alter weather patterns in far flung parts of the world.
You can see abnormally warm surface waters migrating eastward along the equator in the animation above. It starts on March 4 and moves forward in weekly increments to March 25. In the last frame, note that warm pool of water off the coast of South America.
El Niño brings areas of low pressure and increased rainfall to the west coasts of North and South America (including California), according to Columbia University’s Earth Institute. But that’s not all: Read More
| See update below|
The extent of Arctic sea ice in March hit a record low for the month in the satellite era, according to the latest update from the National Snow and Ice Data Center.
Back on February 25, a record low winter ice extent was set.
SEE ALSO: It’s Now Official: Arctic Sea Ice Sets a New Winter Low
The satellite image above, acquired on April 3, shows dark open water in the Fram Strait between Svalbard and Greenland. At this time of year there is typically more sea ice here.
It began relatively modestly as a few plumes of sand blowing out of the northwestern portion of the Arabian Peninsula. Within less than a day, it had transformed itself into a monster.
Or, more accurately, a gargantuan “haboob” — a sandstorm that ultimately swept down the entire peninsula and all the way across the Arabian Sea to Pakistan and India.
SEE ALSO: Deadly Snowboob Envelops Ontario
From April 1 through April 6, the sand moved across an area that by my estimation totaled about 2.4 million square miles. By comparison, the contiguous United States measure 2.9 million square miles.
You can watch the progress of the sandstorm in the animation above consisting of images acquired by the Suomi NPP satellite. (The acquisition dates for each image are listed in the lower right corner. Also, the first and last images in the animation pause longer than the others.) For an image showing the haboob’s relatively humble beginnings in the northwestern part of Saudi Arabia, click on the thumbnail at right. I’ve circled the area in question.
As it grew and gained force, the sandstorm caused quite a bit of mayhem. As described by the Cooperative Institute for Meteorological Satellite Studies:
The blowing sand reduced surface visibility to near zero at some locations, disrupting ground transportation, air traffic, and also closing schools. Visibility was reduced to 0.1 mile for several hours at Dubai International Airport . . . which is one of the world’s busiest in terms of volume of flights.
The news out of California this past Wednesday was so grim that it once again grabbed headlines away from another region that is suffering too.
Following Wednesday’s news that snowpack in California’s Sierra Nevada range is virtually gone, today the U.S. Natural Resources Conservation Service announced that snowpack in the Cascades of Oregon and Washington is also at record lows.
You can watch it pretty much vanish year to year in the animation above. I created it using three images acquired by NASA’s Aqua and Terra satellites. The sequence starts on March 30, 2013, moves to April 7, 2014, and concludes with an image acquired this past March 26th.
The main culprit here has not been primarily a lack of precipitation, which was only a little lower than normal in Oregon. As has been the case in California (which experienced low precipitation this winter but not record low), and elsewhere in the western United States as well, snowpack in the Cascades has taken a really big hit from exceedingly warm temperatures.
Micronesia’s Caroline Islands have been taking a beating today from Category 5 Super Typhoon Maysak.
As of 2 p.m. today EDT (morning on Wednesday in Micronesia), the Joint Typhoon Warning Center pegged Maysak’s strongest sustained winds at 160 miles per hour, with gusts to 195 mph.
This makes Maysak “one of only three Category 5 storms ever observed in the Northwestern Pacific prior to April,” according to Jeff Masters of Weather Underground.
Also, Maysak’s development has caused two records to fall, Masters says: Read More
On March 18th, I posted a story about the other big drought story you need to pay attention to — not the one in California, which has been garnering most of the headlines but the one that has been afflicting the Colorado River Basin.
Since then, I’ve been keeping an eye on how our snowpack has been doing. And now, at the end of the month, I’m sorry to report that it’s not doing well at all.
The main culprit: High temperatures — outrageously so in some areas — have been causing premature melting of high mountain snows and early runoff.
I made the animation above to illustrate what’s happening. It consists of two pairs of images from NASA’s Terra and Aqua satellites. The view stretches from the eastern front of the Rocky Mountains on the right to the Utah-Nevada border on the left. (Also included are snippets of Wyoming to the north and New Mexico and Arizona to the south.)
I’ve chosen both natural and false color images to illustrate what has happened. In both pairs, the first image was acquired on March 5th, and the second on March 30. In the false color images, the reddish tones are indicative of snow.
In both cases, the shrinkage of the West’s snowpack is stunning. And just for the record, our eyes are not fooling us.
Some of the biggest declines have occurred in Colorado’s San Juan mountains, in the southwestern corner of the state. Here’s the data illustrating what has happened there: Read More
Yesterday, I posted a story about the Halley Research Station on Antarctica’s Brunt Ice Shelf. I titled it a “Winter Postcard from Antarctica,” and it included photos and comments about life at the station from Tom Welsh, the wintertime manager there.
Well, I was so busy putting that post together that I missed the big news yesterday about Antarctic ice shelves in general: They are thinning faster than previously thought.
This is a big deal because these ice shelves act like dams that impound giant glaciers behind them, slowing their movement to the sea. So as these ice shelves erode, it allows the glaciers to flow more quickly, releasing more ice into the sea and thereby raising sea level.
The new findings have been reported widely elsewhere, including this excellent overview by Andrew Freedman at Mashable. So I won’t go into them in great detail here.
But I thought I’d share a quick summary as well as some imagery that can help explain what’s going on. Read More