Tag Archives: extreme weather

Hurricane Matthew Slams the Southeastern US

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Hurricane Matthew, the 13th named storm of the Atlantic Hurricane Season, hammered the southeastern United States this weekend from Florida to Virginia.

Tearing up the coast as it trekked northward, Matthew made landfall near McClellanville, SC on Saturday as a category-1 hurricane with 75mph winds. It had reached category-5 status in the Caribbean – the first storm to do so since Hurricane Felix in 2007- but weakened as it moved toward the US.

Despite this downgrade, Matthew still packed a powerful punch. Its strong winds, flooding rains, and storm surge caused significant property damage and widespread power outages throughout the region. The death toll from this storm currently stands at 26 people from across five states and is expected to increase in the coming days.

With successive bands of heavy rain, Matthew also caused catastrophic inland flooding. In Fayetteville, NC – 100 miles from the coast – 14.82 inches of rain was reported. As a result, several rivers in the region rose to record or near-record levels and overflowed their banks, inundating communities.

All told, Matthew dumped 13.6 trillion gallons of water on Florida, Georgia, South Carolina, North Carolina, and Virginia before heading out to sea as a post-tropical storm. That is enough water to fill over 20 million Olympic-size swimming pools. The highest rainfall total, 17.49 inches, was reported near Savannah, GA.

The damage caused by Matthew is currently estimated at $6 billion.

Hurricane Matthew batters the south eastern US. Credit: NOAA/NASA

Hurricane Matthew batters the southeastern US. Credit: NOAA/NASA

Hurricane Hermine Batters Florida’s Gulf Coast

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Hurricane Hermine, the eighth named storm and fourth hurricane of the 2016 Atlantic Hurricane Season, made landfall in the Big Bend region of Florida early Friday morning. It slammed the Sunshine state’s west coast from Tampa to Tallahassee with heavy rain and winds measured up to 80 mph.

The category-1 hurricane generated a 9-foot storm surge in Cedar Key and dumped more than 22 inches of rain in parts of Pinellas County, flooding many communities. The storm also downed trees and knocked out power to over 250,000 people. Only one storm related death was reported.

Traveling across Florida, Hermine was downgraded to a tropical storm. It is now in the Atlantic moving north along the eastern seaboard. Impacts such as powerful winds, heavy rain, coastal flooding, and dangerous rip currents are expected to be felt from Georgia to Connecticut this holiday weekend.

Hermine was the first hurricane to make landfall in Florida in eleven years.

Hurricane Hermine makes landfall in Florida on September 2, 2016. Credit: NOAA

Hurricane Hermine makes landfall in Florida on September 2, 2016. Credit: NOAA

Historic Flooding in West Virginia

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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 West Virginia. Credit: ABC11

Flooding in Richwood, Nicholas County, West Virginia. Credit: J. Rose/ABC11

El Niño Comes to an End

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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.

Data: NOAA/CPC

ENSO records date back to 1950. Data: NOAA/CPC

Tropical Storm Colin Barrels into Florida

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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 at 12:20 ET June 6, 2016. Credit: NASA

Tropical Storm Colin over the Gulf of Mexico on June 6, 2016. Credit: NASA

Severe Weather Outbreak in Midwest brings Oklahoma an EF-4 Tornado

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Over the past few days, severe weather – including a series of tornadoes – has been roaring across the Midwest. These powerful storms have caused widespread damage and claimed the lives of at least two people.

According to the NWS, thirty-eight tornadoes have been confirmed so far across ten states. The strongest was rated EF-4, the second highest ranking on the Enhanced Fujita Scale.  With winds raging between 166 and 200 mph, it devastated the area around Katie, Oklahoma on Monday afternoon. This was the first EF-4 twister of 2016.

On Wednesday, another round of severe storms brought accumulating hail to Omaha, Nebraska. More than twelve inches piled up on the ground, requiring snowplows to clear the streets.

Year to date, this tornado season has been fairly quiet. But, as this latest outbreak shows, it only takes one storm to devastate a community. May is typically the most active month of the year for severe weather in the US.

Tornado touches down near Katie, Oklahoma. Credit: KJRH

An EF-4 tornado touches down near Katie, Oklahoma. Credit: KJRH

Historic Flooding in Houston

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Relentless rain unleashed catastrophic flooding across southeast Texas on Monday. Local officials say this was the worst flooding event the region has seen in years.

Rainfall totals across the Houston metro area varied, but some places saw nearly 17 inches in less than 24 hours. The NWS office in Houston reported 9.92 inches of rain at Houston Intercontinental Airport (IAH), making it that city’s second wettest day on record. On average, Houston typically gets 3.46 inches of rain for the entire month of April.

The intense rainfall caused bayous to swell out their banks and flood homes, businesses, and major roadways – effectively paralyzing large parts of this country’s 4th largest city. Rainfall rates reached as high as 3 to 4 inches per hour in some spots, which prompted the NWS to issue a flash flood emergency (the highest level of flood alert) for the area. Local officials say 5 people were killed and more than 100,000 people lost power as a result of the flood.

The primary driver behind this extreme rain event was also main reason why the eastern US has been unseasonably warm and dry recently. The omega block that sat over the country for the past few days basically set up a large ridge of high pressure in the east and blocked an upper-level low from moving past the Four Corners region. Essentially stuck in place, the upper-level low funneled in massive amounts of moisture from the Gulf of Mexico. That moisture was then forced to rise and cool when it interacted with the stationary front in the area. The result was an extended period of thunderstorms and intense rainfall.

Southeast Texas is no stranger to flooding. In fact, this was the fourth major flood to hit the area in the past twelve months. The previous three took place in May, June and October of 2015. But, officials in Houston say Monday’s event was the largest flood the area has seen since Tropical Storm Allison in 2001. That storm dumped more than 35 inches of rain on the Houston metro area over the course of five days and caused $5 billion worth of damage.

The Governor of Texas, Greg Abbot, has declared 9 counties to be disaster areas as a result of Monday’s storm.  More rain, unfortunately, is forecast for the region this week.

View of flooding in downtown Houston, TX. Credit: KHOU

View of flooding in downtown Houston, TX.  Credit: KHOU

Hurricane Alex: A Rare January Storm in the Atlantic

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January, a winter month in the northern hemisphere, is a time when we are usually talking about snowstorms. Nevertheless, Hurricane Alex, the first named storm of the 2016 Atlantic Hurricane season has officially formed.

According to the National Hurricane Center, Alex is the first Atlantic hurricane to form in January since 1938. With sustained winds of 85 mph, it is the second strongest January hurricane on record. Hurricane Alice, which formed at the end December 1954 and lasted through early January 1955, had winds that peaked at 90 mph.

Alex transitioned from a sub-tropical storm – a storm that has both tropical and non-tropical characteristics – into a fully tropical system on Wednesday and then strengthened into a category-one hurricane on Thursday morning.  This type of rapid intensification is usually associated with the storm moving over very warm ocean waters. In this case, however, the sea surface temperatures in the area were above average, but just barely warm enough to support tropical development. So, according to NOAA, Alex likely got an extra boost from an unstable atmosphere. The wide temperature spread between the warm surface air and a pocket of unusually cold air aloft encouraged convection and helped strengthen the warm core of this off-season storm.

Alex is currently located 490 miles south of the Azores and moving north-northeast at about 20 mph. It is expected to bring strong winds, heavy rain, and storm surge flooding to that archipelago over the next 24 hours.

The Atlantic hurricane season traditionally runs from June 1 to November 30th.

Hurricane Alex's forecast track. Credit: NOAA/NHC

The forecast track for Hurricane Alex. Credit: NOAA/NHC

From Drought to Flood: Weather Whiplash in Texas

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Bouncing between the extremes of drought and flood, the weather whiplash in Texas continued this weekend. For the second time this year, torrential rain caused widespread flooding across the Lone Star State.

The city of Corsicana, south of Dallas, saw more than 18 inches of rain between Friday and Saturday. Flash floods caused extensive damage and even derailed a Union Pacific freight train. In Houston, where they received 8 inches of rain on Saturday and Sunday, bayous swelled out of their banks and flooded roadways. Local officials say Buffalo Bayou near the downtown area rose 20 feet in just 12 hours.

The cause of this prolonged rain event involved the interaction of a few key atmospheric players. First, an area of high pressure over the east coast – with a clockwise circulation – pushed tropical moisture across the Gulf of Mexico and into Texas. Then, there was a strong upper level low – with a counter clockwise circulation – over the southwest and a cold front moving southeast. These added lift to the atmosphere. When the warm saturated air was forced to rise, it cooled. Since cool air holds less moisture than warm air, the moisture was wrung out of the atmosphere in the form of intense rain. Then, on the heels of all that, remnants of Hurricane Patricia from the Pacific Ocean traveled across Mexico and into Texas. It brought even more tropical moisture into the mix.

Ironically, much of Texas was in a drought just last week. It was considered a “flash drought” as it developed very quickly this summer after intense rains and catastrophic flooding in May brought the previous drought to an abrupt end. From drought to flood to drought and back to flood, Texas certainly has had a wild ride with weather this year.

Credit: NBC Train derailed by flood waters near Dallas, TX

Freight train derailed by flood waters near Corsicana, TX. Credit: NBC News

Drought Update: Autumn 2015

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This autumn season has been marked by a number of intense rain and flooding events across the US, from South Carolina to California.  Drought, however, continues to plague large sections of this country.

According to the latest report from the US Drought monitor, 58.96% of the nation is in some form of drought. Many areas in the mid-west and the northeast are listed as abnormally dry or experiencing moderate drought. But, it is the western and southern states that have been particularly dry.

In California, despite some unusually heavy rain recently, the long-term drought continues. In fact, 99.86% of the state is experiencing conditions of moderate drought or worse, with 46% in exceptional drought – the worst possible category. These extremely parched conditions have helped fuel an explosive wildfire season across the Golden State.

As discussed in an earlier post, the multi-year drought in Texas came to an abrupt end this past spring with intense rainfall and catastrophic flooding across the region. Over the summer, however, drought conditions returned. Developing fairly quickly, this is known as a flash drought. As of this week, 65.25% of the massive Lone Star State is in some form of drought and 21.40% is in extreme drought. That is serious weather whiplash!

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.

USDrought_102015

Credit: US Drought Monitor.