It was a great thrill to be asked back to The Weather Channel’s WUTV show tonight! As a personal weather station owner based in New York City, we discussed the heat wave that has been baking the Big Apple.
The show, which dives into the science behind different weather events, airs weeknights from 6 to 8 PM EST on The Weather Channel.
Weather Gamut writer, Melissa Fleming, talks with Mike Bettes on WUTV. July 26, 2016.
This summer has been marked by heavy rain and even flooding in many parts of the United States. Drought, however, continues to plague large sections of the country.
According to the latest report from the U.S. Drought Monitor, 41% of the nation is in some form of drought. Many areas in the south and northeast are listed as abnormally dry or experiencing moderate drought. But, it is the western states that have been particularly parched.
One of the hardest hit states is California, which is now in its fifth consecutive year of drought. In fact, 100% of the Golden State is currently experiencing some form of drought with 43% in extreme drought. These exceptionally dry conditions have provided the fuel for an early and explosive start to the region’s wildfire season.
Deprived of water, trees in California have not been able to produce the sap that helps protect them from insect infestations. This has left them vulnerable to attack by bark beetles, especially as the temperature warms. Together, the drought and these insatiable insects have increased the rate of tree mortality in the state over the past few years. According to a recent survey by the U.S. Forest Service, 66 million trees have died in the Sierra region of California since 2010. That is an increase of 26 million since the last count in October. Sadly, as the drought continues, more trees are expected to die, further elevating the risk wildfires.
The Drought Monitor is a weekly publication produced by a partnership of government agencies, including the National Drought Mitigation Center, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration.
41% of the US and 100% of California is in some form of drought. Credit: US Drought Monitor
Relentless rain unleashed catastrophic flooding across West Virginia late last week. Officials say it was the state’s worst flood disaster in more than a century.
According to the NWS, the Mountain State received about 25% of its average annual rainfall in just a few hours. In Greenbrier County, more than 10 inches of rain fell between Thursday and Friday. This massive amount of precipitation in such a short period of time overwhelmed rivers and streams throughout the area. In Kanawha County, which includes the state capital of Charleston, the Elkview River crested at 33.37 feet – its highest crest in more than 125 years of record keeping.
The raging torrents of floodwater damaged or destroyed thousands of homes and businesses, as well as infrastructure across the state. To date, twenty-three weather-related deaths have been reported and more than 10,000 customers are still without power.
This type of rainfall is considered a one in one thousand year event in West Virginia. That does not mean it can only happen once every thousand years. It is the recurrence interval, a statistical calculation that means an event has a one in one thousand chance (0.1%) of happening in any given year in a given location.
The cause of this devastating flooding was twofold and involved a combination of weather and topography. First, “training” thunderstorms developed along a boundary between cooler air to the northeast and warm, moist air to the southeast. This is a meteorological phenomenon where strong storms flow continuously over the same area for a relatively short period of time – like train cars traveling along a track – dumping excessive amounts of rain.
The second major player in this deadly deluge was the state’s mountainous topography. When substantial rain falls in hilly terrain, it runs downslope very quickly and causes flash flooding in valleys, where most people tend to live. Moving with tremendous force, this type of fast flowing water can pick up and destroy almost anything in its path.
The Governor of West Virginia, Earl Ray Tomblin, has declared a state of emergency in 44 of the state’s 55 counties as a result of the flooding. Additionally, President Obama declared a major disaster in three of the hardest hit counties – Kanawha, Greenbrier, and Nicholas – which allows federal funds to supplement state and local emergency efforts.
Flooding in Richwood, Nicholas County, West Virginia. Credit: J. Rose/ABC11
The latest El Niño event officially ended in early June. But now, according to NOAA, there is a 75% chance that La Niña conditions will develop by the close of this summer.
El Niño and La Niña are opposite phases of a natural climate pattern known as the El Nino-Southern Oscillation or ENSO. A La Niña event is characterized by below average sea surface temperatures in the central and eastern equatorial Pacific. These cool waters influence the air temperature and affect the position of the jet stream.
In general, La Niña strengthens the polar jet and weakens the sub-tropical jet. This, in turn, affects weather patterns around the globe.
In the US, a La Niña event typically brings the southern states conditions that are warmer and dryer than normal. The northern tier, on the other hand, usually experiences below average temperatures with the northwest and Great Lakes region receiving above average precipitation. These impacts are most apparent during the fall and winter months.
La Niña also tends to reduce the wind shear over the tropical Atlantic. This provides favorable conditions for hurricane development.
The last La Niña event occurred in 2010-12.
Typical Winter La Nina jet stream pattern. Credit: NOAA
Wildfire season in the American West typically gets going in the latter part of summer, but this year it is off to an early and explosive start.
As of Wednesday, according to the National Interagency Fire Center, nineteen large wildfires – defined as greater than 100 acres of timber or 300 acres of grassland – are burning in eight states. These include Alaska, Arizona, California, Colorado, New Mexico, Utah, Washington, and Wyoming.
In Santa Barbara, CA, the Sherpa Fire has burned approximately 8,000 acres of land since it began last week. The Reservoir Fire and Fish Fire, both in LA County, have each scorched thousands of acres and forced more than 750 homes to be evacuated. In New Mexico, 24 homes have been destroyed by the Dog Head Fire, which has blackened almost 28 square miles of land near Albuquerque. And, in Arizona, the Cedar Fire has charred nearly 42 square miles of the Fort Apache Indian Reservation.
These huge fires are being fueled by years of drought and bark beetle infestations that have turned the region’s forests and brush areas into parched tinderboxes, making them susceptible to any type of spark. On top of that, a searing heat wave has now exacerbated the situation.
A massive area of high pressure, known as a heat dome, has been sitting over the region for days producing extremely hot and dry conditions. On Monday, according to the NWS, Las Vegas, NV saw the mercury climb to 115°F, Phoenix, AZ reached 118°F, and Palm Springs, CA hit a sweltering 122°F.
Although wildfires are part of the ecosystem in the western US, the early start, massive size, and widespread scope of the current fires are rather unusual. They also come on the heels of the 2015 wildfire season, which was the worst in US history with more than ten million acres burned.
Smoke billows over LA as wildfires burn in the nearby hills of Angeles National Forest. Credit: R. Chiu/AP
It’s official! The El Niño event of 2015-16 has ended.
According to NOAA, the sea surface temperatures in the so-called “Nino 3.4” region of the tropical Pacific have fallen below the El Niño threshold and ENSO-neutral conditions have returned. But, this El Niño episode will not soon be forgotten.
Developing in the spring of 2015, this El Niño was one of the three strongest on record, along with the 1997-98 and 1982-83 events. Transferring heat from the ocean to the atmosphere, it helped make 2015 this planet’s warmest year on record. Coming on top of human-caused global warming, the new record was heads and shoulders above the previous one.
Influencing weather around the world, El Niño is probably best known in the US for bringing heavy rain (and the mudslides that go with it) to southern California. This time, however, the little rain that did come was not enough to end the multi-year drought plaguing the Golden State.
With exceptionally warm sea surface temperatures, the eastern Pacific hurricane season was extremely active. Eighteen named storms developed and thirteen became hurricanes. Hurricane Patricia, with winds measured at 200 mph, was the strongest hurricane ever recorded in the western hemisphere.
By contrast, the 2015 Atlantic Hurricane season was below average. It produced eleven named storms and four hurricanes. This relatively quiet season was largely the result of wind shear in the Gulf of Mexico, generated by El Niño, which helped to hinder most tropical development in the Atlantic basin.
Now that El Niño has dissipated, NOAA expects a La Niña episode – characterized by cooler than average Pacific sea surface temperatures – to develop in the autumn.
ENSO records date back to 1950. Data: NOAA/CPC
Tropical Storm Colin, the third named storm of the 2016 Atlantic Hurricane Season, made landfall in the Big Bend region of Florida on Monday. It slammed the northern part of the Sunshine state with heavy rain and sustained winds measured up to 50 mph.
According to the NWS, more than 10 inches of rain fell in the Tallahassee area and Gainesville posted its second wettest June day on record with 5.65 inches of rain reported. All this precipitation in such a short period of time caused widespread flash flooding. Storm surge flooding was also an issue for communities along the state’s Gulf Coast.
The storm, according to FEMA officials, downed trees and knocked out power to more than 45,000 people between Tampa Bay and Jacksonville.
Traveling across Florida, the storm transitioned to a “post-tropical” cyclone on Tuesday as it moved up the east coast and out to sea.
Colin was the first named storm to hit the Sunshine state since Andrea in 2013. It was also the earliest “C” storm on record to form in the Atlantic Basin.
Tropical Storm Colin over the Gulf of Mexico on June 6, 2016. Credit: NASA
Today is the first day of the Atlantic Hurricane Season. Although two named storms – Alex and Bonnie – have already formed this year, the season officially runs from June 1st to November 30th.
Since 1950, each tropical storm or hurricane to form in the Atlantic has had a unique name. They come from a set of six rotating lists produced by the World Meteorological Organization. A name is retired only when a storm was particularly noteworthy – causing a large number of fatalities or an extraordinary amount of damage. Some retired Atlantic Basin names include: Andrew, Katrina, and Sandy.
The names for this year’s storms are listed below.
| Alex | Hermine | Otto |
| Bonnie | Ian | Paula |
| Colin | Julia | Richard |
| Danielle | Karl | Shary |
| Earl | Lisa | Tobias |
| Fiona | Matthew | Virginie |
| Gaston | Nicole | Walter |
Bonnie, the second named pre-season storm of 2016, made landfall on Sunday just east of Charleston, South Carolina on the Isle of Palms.
According to the NWS, Bonnie was categorized as a tropical storm on Saturday with winds as high as 45mph. But by the time it came ashore, its winds had fallen below 39mph – the threshold for a tropical storm – and was downgraded to a tropical depression. Despite this reduced status, the storm still brought heavy rain, flash flooding, and dangerous rip currents to the area.
Rainfall totals, according to the Charleston NWS office, reached as high as ten inches in some spots. Flash flooding in Jasper County even caused sections of Interstate 95 – one of America’s busiest highways – to close.
Remnants of Bonnie are expected to linger over the southeastern US for the next several days, bringing even more rain to the region.
The Atlantic Hurricane Season official begins on June 1st.
Bonnie makes landfall as a tropical depression near Charleston, SC. Credit: NASA
The number of hurricanes that develop in any given year varies, and this year, NOAA’s Climate Prediction Center is forecasting a “near normal” season in the Atlantic.
Tropical cyclones, known as hurricanes in the United States, develop around the globe at different times of the year. In this country, we are most affected by the Atlantic hurricane season, which impacts the North Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. It runs from June 1 through November 30.
Overall, NOAA predicts a 70% likelihood of ten to sixteen named storms forming this season, of which four to eight could become hurricanes, including one to four major hurricanes. A major hurricane is one that is rated category 3 or higher.
The numbers for this season’s outlook include Hurricane Alex, the unusual storm that developed in the eastern Atlantic in mid-January.
One of the main drivers behind this season’s average to slightly above average forecast is the diminishing presence of El Niño and the likely development of La Niña in the autumn. El Niño conditions tend to suppress tropical activity in the Atlantic while La Niña conditions do the opposite.
After three consecutive below average hurricane seasons in the Atlantic, a normal season will likely feel very active. But regardless of the number of storms that actually form, it is important to remember that it only takes one landfalling system in your community to make it a memorable season.
Source: NOAA