The end of a calendar year is a time to reflect on things which have happened during the previous 12 months; a big part of my life is weather, and weather phenomena lend themselves to compelling visual images. In December 2006 I posted an entry in which I embedded my choices for "weather images of the year," and then the spirit moved me to do it again in 2007 ... and in 2008 ... and now I guess this is the 4th annual!
[December 31 update: My end-of-the-decade entry is here.]
The first version contained just radar and satellite images, and although there are still plenty of them, it has evolved to include photographs and other graphics.
As I have noted the past couple of years, which I'll copy and paste here:
"The following is not meant to represent a complete list of every significant weather event everywhere or images thereof, but there's a lot of stuff which will bring back memories. What was most memorable for you?"
Since there are already a gazillion images included this year, I've limited the focus to the United States, with just a couple of exceptions.
Wherever you are, I hope 2010 is a great year for you, and a safe one weatherwise!
What is a "590 decameter 500 millibar height"? Well, to a meteorologist, that represents something that ya just don't see north of the border in mid-winter. Except that in January 2009, we did!
The weather pattern got crazy early in '09, with that exceptionally strong ridge of high pressure aloft and, downstream, an intense trough of low pressure.
Within the trough was a -52C temperature at the aforementioned level of 500 millibars. The significance of that? It's just about as low as it ever gets in this part of the world (I'm not as familiar with such data above, say, Antarctica).
What did all this mean for those of us living on the Earth's surface, not at 500 millibars (a few miles up)? Extreme warmth juxtaposed with extreme cold.
And it began setting the stage for what happened the following week: what Kentucky Governor Steve Beshear called "the biggest natural disaster that this state has ever experienced in modern history."
Scenes like this one in Arkansas were seen throughout that part of the country.
There was this remarkable overlap with the area that experienced extreme winds from the remnants of Hurricane Ike in 2008!
Just a couple of weeks after the ice storm, another very energetic system brought additional anomalous weather. Look at this set of rotating supercell thunderstorms lined up in Oklahoma on the afternoon of February 10; that's what's to be expected in May, not early February!
That evening, from a different supercell, the community of Lone Grove was hit by an EF4 tornado, the strongest on record in Oklahoma in February. Tragically, 8 people died. Fortunately, no other tornado this year has produced as many fatalities, and nationwide 2009 has been the least deadly year of the decade.
As an exceptionally strong surge of winds aloft at and below the upper-level jet stream altitude blasted northeastward the following day, February 11, it produced a slew of wind damage reports associated with severe thunderstorms in the eastern Ohio/Tennessee Valleys and central/southern Appalachians. That's very unusual for midwinter there. What's more, to the west of that there was also widespread damage from just the cyclone's wind, not thunderstorms. This included, incredibly, places such as Paducah which had experienced both the catastrophic ice storm a couple weeks prior and the wrath of Ike's winds!
After having popped its cork, the atmosphere settled down for awhile, until the final day of February and first day of March, when a potent southern snowstorm brought Jackson, Kentucky its largest one-day snowfall on record on the 28th and then this scene in my front yard near Atlanta on the 1st.
On April 14 I photographed this a couple neighborhoods away from mine. Okay, so I took the photograph, but is there anything notable about the weather situation which warrants inclusion in this year-in-review? Yes! That damage was produced by thunderstorms, but not the typical gusts blowing out along and ahead of the storms. The strong winds were from the east, behind the line of storms ... and this was with but one of a whole series of "wake lows" in the Southeast in mid-April.
Then the weather really got wiggy in May. On the 8th was something unlike anything I could remember seeing before in my career, what I called the "MCV-icane" (for info on what an MCV is as well as the derecho from which the MCV evolved, you can read the blog entry about the event I posted at the time). Based on this pressure graph and radar appearance including an eye, and the strong cyclonic winds associated with both, it sure seemed like a tropical storm or hurricane. But forming over southern Illinois?!
Then in mid-May, what's wrong with this picture(s)?
Mike Bettes was supposed to be chasing tornadoes with VORTEX2! But a big ridge of high pressure aloft squashed that. What's good for people in the Great Plains was not so good for tornado research.
And while Mike B. was lounging by a lake, Mike Seidel was by the Atlantic Ocean getting buffeted by a powerful nor'easter ... in Florida in May?! The system produced strong winds, high surf, and up to 2 feet of rain.
The upper-level retrograding (moving west instead of east) cutoff low (so named because they get cut off from the main jet stream flow) then begat what IMHO was a landfalling tropical storm on the Gulf Coast at Dauphin Island (it wasn't officially so but would have been the earliest in the season to make landfall in the U.S.)
All that stuff moved northwest and evolved into this large swirl of clouds associated with the upper-level low. In May, such upper lows are supposed come to Arkansas by way of places such as Fort Collins, Colorado, not Fort Myers, Florida!
On June 4, another tropical cyclone wannabe with an eye-like feature actually became organized well inland over Georgia!
The next day -- June 5, 2009 -- Mr. Bettes and VORTEX2 hit the jackpot in rural southeastern Wyoming, with the whole life cycle of a photogenic tornado broadcast live on The Weather Channel. It occurred in unpopulated countryside, so the tornado could be enjoyed for its spectacular presence and advancement of the science rather than lamented for producing tragedy like so many twisters do.
Speaking of storm chasing, Wayne Meinhard does it from the sky. I love this photograph of lightning striking the Earth that he took in June from above in his airplane!
And, speaking of photographs taken from above, look at this cumulonimbus cloud and anvil photographed by astronauts on the International Space Station! The NASA website indicates that the photo was actually taken in 2008, but this July 2009 article helped get the image more attention.
Here's a classic radar image. But what's out of the ordinary about it -- why include it here? Because it was a supercell, racing quickly, and doing so toward the due south in western Kansas, in July. That's not something you see every day!
It was a function of the flow between a hot ridge of high pressure over the western U.S. and a cold trough to the east on that day, which in turn was representative of the pattern during July. Six states had their coolest July on record.
Things took a nasty turn in early August, when on the morning of the 4th torrential thunderstorms swallowed up Louisville, Kentucky and produced severe flash flooding.
Late August brought the "Station Fire," whose smoke cloud loomed beyond the skyline of downtown Los Angeles and whose flames had me on edge when they came very close to a close relative's home in La Crescenta, a northern suburb of L.A.
The fire didn't quite make it to her house; while it did reach some communities in Southern California, it would have been a far more widespread disaster if rather than breezes being relatively light there had been a strong Santa Ana wind to fan the flames.
On September 11, yet another tropical storm wannabe affected the U.S. This one was a hybrid with characteristics of both tropical and non-tropical systems. It brought strong winds to southern New Jersey as it made landfall while moving northwest from the Atlantic, an atypical direction.
That was an inauspicious sign that the pattern was getting weird again. The atmosphere got all clogged up across the U.S. during September, with slow-moving and retrograding cutoff lows, one of which actually did a 360 degree loop from Saskatchewan to South Dakota and back to Saskatchewan! The series of satellite images showing that is too long to embed within this entry, but you can see it here. Later in the month a record was set for the highest 500 millibar height so late in the season so far north in the U.S., as illustrated by this ridge which pushed the jet stream waaay north.
In the midst of this goofiness came a flood calamity, with a phenomenal amount of rain in the metro Atlanta area, as much as 20+ inches coming in a short period of time. My neighborhood was spared the brunt, but other TWC employees live in/near the white area on the map below.
Mike Seidel was a busy bee providing live coverage this fall, and on October 16 he was in the State College, PA area when its record was smashed for so heavy a snowfall so early in the season.
That was part of a very cold pattern, and autumn 2009 was characterized by a remarkable flip-flop in temperatures from October to November.
Amidst the November warmth came "Nor'Ida" as the non-tropical remnants of Hurricane Ida became a monstrous nor'easter slamming the Mid-Atlantic coast. Major coastal flooding hit the Norfolk, Virginia area, and Nor'Ida was one of the most severe and widespread beach erosion events in memory. Scenes like the one in this photograph from Fenwick Island, Delaware, as submitted to iWitness Weather on November 14, were commonplace all the way from North Carolina to New Jersey, and even Long Island had its sand scoured by battering waves on top of elevated water levels.
When it comes to actual hurricanes and tropical storms, though, and the wannabes noted in this entry notwithstanding, the United States and other countries were blessed by a relatively quiet and innocuous Atlantic hurricane season for both the total number of storms/hurricanes and landfalls.
In other parts of the world it wasn't so quiet. Here's one tropical cyclone whose images from late November we can both be in awe of and enjoy, given that the Super Typhoon -- Nida, not to be confused with Nor'Ida! -- was safely out at sea in the western Pacific.
Back in the U.S., yet another upper-level cutoff low (the "Year of the Cutoff"??) created this eye-catching "water vapor" satellite image in November. The cutoff's nature was unusual for November, and was an omen for what would happen as the final month of the year drew to a close.
That cutoff was upstream from the remnants of Ida, whose moisture infused a North Atlantic storm that brought extreme rainfall and flooding to the UK.
December had back-to-back-to-back major storms, starting with one on the 8th and 9th which first produced a harsh blizzard in the Plains. It also resulted in a bulls-eye of heavy snow accumulations in Madison, Wisconsin and a big "snowfall gradient" in the Milwaukee area; a record low pressure in Grand Rapids, Michigan and strong winds all across the Great Lakes region, which brought back memories of another November storm, the one in 1975 which sunk the Edmund Fitzgerald; a line of intense thunderstorms moving across Lake Erie and western NY/PA despite temperatures as low as the upper 30s; and for those interested in technical talk, a 500 millibar height fall in 12 hours of 30 decameters / 300 meters, which ties the greatest I can remember offhand in my career (the other being on November 15, 1989, the day of the Huntsville F4 tornado).
Then on the 10th a lake-effect snowband, which appeared to be infused with moisture from two other streams, extended all the way to Maine!
On December 18, a low pressure system cranked up over the Gulf of Mexico. Unlike all those tropical storm wannabes this one didn't have "convection" surrounding the center -- what you see below is a circular area of mainly just shallow low clouds -- but nevertheless this was another striking "eye" appearance on imagery!
The system would go on to become a whopper snowstorm in the Mid-Atlantic region and thereabouts. I don't know how to embed this Java loop within this blog and do so within the column width limit, but click on this link and check out the super rapid scan visible satellite loop of the storm when the center was east of the Outer Banks on the 19th!
Finally, as the month wore on, the "Arctic Oscillation" (AO) went off the chart -- literally! This apparently included a record negative value for December.
Click on the image below for the full-sized montage of the storm, showing that it culminated in a humongous cutoff low (this is what I was referring to when I said the one in November turned out to be an omen for what was to come in late December).
IMAGE(S) OF THE YEAR
I couldn't pick just one. Like last year with the size of Hurricane Ike's wind field, this year my choice for images that I found to be most stunning are those which existed not during or after the event, but rather beforehand. And while not as visually striking as some of the others, these two are ones which from a meteorologist's perspective represented surreal, OMG moments. Yet they were also very real, as although just computer model forecasts, they were highly plausible ones that were expected to verify. They showed an extreme set of ingredients coming together, loaded with potential that forecasters were confident would be realized.
This depiction below of the predicted wind field (colors show velocities, purple/red being strongest) in advance of Nor'Ida shows tandem low pressure centers (which I've labeled with "L"). The role of the one farther out at sea is that it helped to extend the fetch of winds produced by the difference in barometric pressure between the lows and a sprawling high pressure system to the north.
For wave growth and beach erosion in a situation like this, the keys are the strength of the wind, the length of the fetch, and the duration. What this case lacked in velocity (winds were strong but not especially so by ocean storm standards) it compensated for in the distance of the fetch and in its duration. This forecast map shows the wind blowing across hundreds of miles and aimed directly onshore, and other model output showed that it would persist through multiple high tide cycles, which is what happened and produced the epic erosion event and the Tidewater flooding.
And last but not least ...
I remember staring in amazement and horror in late January at the models' forecast for precipitation amounts. I failed to save the actual images I was seeing at the time, but this plot from the archive displays the exact same data on a map. What was alarming about the 1-3" of precipitation being forecast was the expected temperature profile in the atmosphere to go along with it: above-freezing air streaming in on top of a very shallow layer of well below-freezing air, the recipe for a severe ice storm. The only uncertainty was in regard to freezing rain (the bad stuff) vs. sleet (not so bad), but all signs pointed to a preponderance of the former.
This enabled plenty of advance warning by meteorologists, but there was nothing that could be done to prevent the freezing rain from accumulating on trees and power lines and bringing them down. 1-3" of "liquid equivalent" is a heckuva lot of precipitation to fall primarily as freezing rain.
Per this report there were still large piles of debris remaining in early November, and smoke filled the air as they were burned.
Photo credits for those other than the ones taken by me/TWC: Associated Press (ice storm and Station Fire); MSalvio (erosion); Wayne Meinhard / ConvectionConnection.net (aerial lightning); Image Science & Analysis Laboratory, NASA Johnson Space Center (cumulonimbus cloud & anvil from the ISS)
Source of other weather images: TWC; NOAA; GRLevelX; Wright-Weather; Penn State University; Illinois State Water Survey; NRL Monterey; UCAR; NASA/GSFC, MODIS Rapid Response; NASA Earth Science Office; University of Washington; University of Wisconsin-Madison
Be prepared, make sure your family is ready to weather the storm.