May 2017: A Month of Weather Extremes in NYC

May was a month of weather extremes is New York City this year. Highs ranged from a cool 53°F to a record warm 92°F. May also produced the city’s first heat wave of the year. However, with 24 out of 31 days posting below average readings, the chill won out in the end. The city’s mean temperature for the month was 61.1°F, which is 1.3°F below average.

In terms of precipitation, May was unusually wet. In all, 6.38 inches of rain were measured in Central Park. Of this impressive total, 3.02 inches (47% of the monthly total) fell in just a few hours on May 5, setting a new rainfall record for the date. Another 1.61 inches came down during an unseasonable nor’easter on May 13. On average, the Big Apple gets 4.19 inches of rain for the entire month of May.

Credit: The Weather Gamut

The Active Atlantic Hurricane Season of 2016 Comes to a Close

The 2016 Atlantic Hurricane Season officially ends today.  Not only was it above average, as predicted, it was the basin’s most active season since 2012.

According to NOAA, there were fifteen named storms this season. Of these, seven developed into hurricanes and three – Gaston, Nicole, and Matthew – were major hurricanes with ratings of category 3 or higher on the Saffir-Simpson Scale. An average season produces twelve named storms, six hurricanes, and three major hurricanes.

This season’s Accumulated Cyclone Energy (ACE), which measures the intensity and duration of storms, was also above normal. On average, a season will post an ACE of 104 in the Atlantic. This year, according to hurricane researchers at Colorado State University, it was 134.

Officially running from June 1 to November 30, the 2016 season got off to an unusually early start. Hurricane Alex developed in January and made landfall in the Azores. It was the first Atlantic hurricane to occur in January since Hurricane Alice in 1955.

Of the season’s 15 named storms, five made landfall in the US –  Bonnie, Colin, Julia,  Hermine, and Matthew. Hermine was the first hurricane to make landfall in Florida in 11 years, ending the Sunshine State’s so called “hurricane drought”. The biggest headliner of the season, however, was Hurricane Matthew.

Matthew was the first storm to reach category-5 strength in the Atlantic in nine years. It weakened as it moved northward parallel to the US coast, but unleashed powerful winds and a damaging storm surge in Florida, Georgia, and South Carolina. The storm officially made landfall in South Carolina as a Category-1 hurricane, but its rain bands reached well inland and caused catastrophic river flooding in both North and South Carolina. In Fayetteville, NC – 100 miles from the coast – 14.82 inches of rain was reported.

This active hurricane season was largely the result of above average sea surface temperatures in the Atlantic and ENSO neutral to cool La Niña conditions in the Pacific. With warm water to fuel storms coupled with reduced wind shear across the Gulf of Mexico, tropical development in the Atlantic basin was essentially unhindered.

Despite this busy season, the US has luckily not been hit by a major hurricane since Wilma in 2005. With records dating back to 1851, it is the longest such stretch on NOAA’s books.

Source: NOAA

Source: NOAA

Drought Update: Autumn 2016

This autumn has been marked by heavy rain and catastrophic flooding in some 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, 49% of the nation is dealing with drought. While this number represents a slight improvement for parts of the west, both the southeast and northeast have been drying out.

Currently, 57% of the southeastern US is in some form of drought and 21% is suffering from conditions of extreme drought. These parched conditions, which have been building for months, are now fueling wildfires across the region. According to the US Forest Service, 59 of the 61 active large wildfires burning in this country are in the southeast.

Another hard hit area is the northeast, where 19% of the region is in severe or extreme drought. Water restrictions are in place in parts of Massachusetts and communities in New Jersey are asking residents to conserve water voluntarily.

On the other side of the country, California – now in its fifth year of drought – received some much-needed rainfall recently. However, most of it fell only in the northern counties. Overall, 88% of the Golden State remains in some form of drought with 21% in exceptional drought, the worst possible category.

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.

Credit: US Drought Monitor

Credit: US Drought Monitor

Hurricane Matthew Slams the Southeastern US

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

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

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

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

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

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

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