Thursday, June 29, 2017

Winter Storm + Tropical Landfall on Mother's Day

Mother's Day 2015 was a strange one, meteorologically.
First, Tropical Storm Ana became the record earliest tropical or subtropical storm to make landfall on the U.S. Atlantic seaboard (neglecting a weird Groundhog Day 1952 Florida tropical storm), according to Stu Ostro, senior meteorologist at The Weather Channel.
Since it was still only early May, High Plains snowstorms were still within the realm of climatological possibility, and 2015 delivered with Winter Storm Venus dumping up to 2 feet of snow.
A landfalling tropical storm and a major winter storm simultaneously hitting on one early May weekend. Amazingly, this wasn't the first time this has happened -- but it's still rare enough to make our list.

Brutal Winter to Record-Warm May

Syracuse, New York - 2015 Temperatures Through Late June

Daily high and low temperatures (dark blue trace) in 2015 through June 24. Blue arrows highlight period of persistent winter cold. Red arrows highlight period of persistent spring warmth. The average daily temperature range is shown by the brown-shaded area.  (NWS-Binghamton)
We just mentioned the incredible New England snow. That same stubborn pattern contributed to the second coldest February on record dating to 1895 in nine Northeast states, including all of New England, New York, Pennsylvania and Ohio.
February 2015 wasn't just the record coldest February in Syracuse, New York. It was also their coldest single month dating to 1903. Their average temperature during the month, taking into account actual highs and lows, was 9 degrees.
By May, the pattern shifted, making record warmth the talk of the Northeast. New Hampshire, Massachusetts, Connecticut and Rhode Island each sweat through their record warmest May. Cities such as Concord, New Hampshire, and Rochester, New York, set record warm Mays. Syracuse just missed out on that lofty pedestal marking their third warmest May.

Strange Severe Slump

Map of all severe thunderstorm and tornado watches issued by the Storm Prediction Center from March 1-23, 2015. That's right, there were none.  (Storm Prediction Center)
This is a map of all the thunderstorm and tornado watches NOAA's Storm Prediction Center posted in the U.S. from March 1 to March 24. Notice it's blank? Yeah. That's weird.
"This has never happened in the record of SPC watches dating back to 1970," said Greg Carbin, Storm Prediction Center warning coordination meteorologist in a SPC. "We are in uncharted territory with respect to lack of severe weather."
March 2015 ended with only 10 tornadoes nationwide, the fewest in any March since 1969. Over the previous 20 years, 78 tornadoes have touched down in March. This followed a February with only three tornadoes.
A jet-stream pattern suppressing warm, moist Gulf of Mexico air from making it into the central and eastern U.S. helped to put a lid on severe weather from January 5 through March 23. The virtual absence of any severe thunderstorms deep into March was odd, to say the least.

2017 hurricane season follows year of extremes

The 2016 Hurricane Season is the longest hurricane season since 1951, making the 2016 season the 2nd longest on record. That's the conclusion drawn in a paper just published in Geophysical Research Letters.
Lead author Jennifer Collins, PhD, associate professor in the School of Geosciences at the University of South Florida in Tampa, FL, writes "Overall 2016 was notable for a series of extremes, some rarely and a few never before observed in the Atlantic basin, a potential harbinger of seasons to come in the face of ongoing global climate change."
"The 2016 North Atlantic Hurricane Season: A season of Extremes" examines 15 tropical storms, seven hurricanes and three intense hurricanes. The season was slightly above average when considering Accumulated Cyclone Energy (ACE), which the National Oceanic and Atmospheric Administration (NOAA) uses to measure cyclonic activity.
Hurricane Alex started the 2016 season in January, causing minor damage in the Azores. The season ended 318 days later in late November when Otto made landfall over southern Central America. Otto was record-breaking in location and intensity being a high-end Category 2 storm.
In October, Hurricane Matthew became a Category 5 at the southernmost latitude on record for the North Atlantic Ocean. It was the first Category 5 in almost a decade and ended the longest stretch without one since 1950. Matthew claimed more than 600 lives, mainly in Haiti, and caused $15 billion in damage.
Up until that point, conditions had been extremely dry. A dramatic change in relative humidity lead to the month generating more than 50% of the season's ACE. It's also the first October to have two Category 4 or stronger storms.

Increased risk of ozone loss over the United States in summer

A new study out of Harvard University reveals that the protective stratospheric ozone layer above the central United States is vulnerable to erosion during the summer months from ozone-depleting chemical reactions, exposing people, livestock and crops to the harmful effects of UV radiation.
Powerful storm systems common to the Great Plains inject water vapor that, with observed temperature variations, can trigger the same chemical reactions over the central United States that are the cause of ozone loss over the polar regions, according to a new paper published in the Proceedings of the National Academy of Sciences.
The paper, led by James G. Anderson, the Philip S. Weld Professor of Atmospheric Chemistry at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), found that stratospheric ozone concentrations over the United States in summer are vulnerable to both increases in water vapor and observed variations in temperature from storm systems over the Great Plains. Increased frequency and intensity of these storm systems, as well as longer-term decreases in stratospheric temperatures, are expected to accompany climate change.

The dust storm microbiome

Israel is subjected to sand and dust storms from several directions: northeast from the Sahara, northwest from Saudi Arabia and southwest from the desert regions of Syria. The airborne dust carried in these storms affects the health of people and ecosystems alike. New research at the Weizmann Institute of Science suggests that part of the effect might not be in the particles of dust but rather in bacteria that cling to them, traveling many kilometers in the air with the storms.
Some of these bacteria might be pathogenic -- harmful to us or the environment -- and a few of them also carry genes for antibiotic resistance. Others may induce ecosystem functions such as nitrogen fixation. Prof. Yinon Rudich and his research group, including postdoctoral fellow Dr. Daniela Gat and former research student Yinon Mazar, in Weizmann's Earth and Planetary Sciences Department investigated the genetics of the windborne bacteria arriving along with the dust.

Widespread snowmelt in West Antarctica during unusually warm summer

An area of West Antarctica more than twice the size of California partially melted in 2016 when warm winds forced by an especially strong El Nino blew over the continent, an international group of researchers has determined.
In the June 15 issue of the journal Nature Communications, they report that the warm spell persisted for more than two weeks in January 2016. Satellite data revealed a mix of melted snow and ice over most of the Ross Ice Shelf -- a thick platform of floating ice that channels about a third of the ice flowing from the West Antarctic Ice Sheet into the ocean.