Ex-Hurricane Ophelia Batters Ireland

The remnants of Hurricane Ophelia, the 15th named storm of the 2017 Atlantic Hurricane season, slammed the Republic of Ireland on Monday. It was the strongest storm on record to hit that country.

Ophelia peaked as a category-3 hurricane near the Azores over the weekend, becoming the most intense storm ever observed that far north and east in the Atlantic Basin. Then, it rapidly transitioned to a post-tropical storm that was labeled Ex-Hurricane Ophelia by Met Éireann, Ireland’s national weather service. This means the storm was drawing energy from the difference in air masses rather than the heat and moisture of the ocean.

Despite this technical downgrade, Ophelia still packed a punch. The storm’s powerful winds, which averaged around 57mph, uprooted trees and downed power lines. It also produced significant storm surge flooding along the country’s west coast. Officials say at least three fatalities have been reported and more than 300,000 people are without power.

At Fastnet Rock, off the coast of County Cork, a wind gust of 119mph was reported. If confirmed, it will be the fastest wind gust ever recorded in Ireland.

On the eastern side of the storm, smoke and dust from the wildfires burning in Spain and Portugal were funneled northward over the UK. This caused the sun and sky to appear red in a large part of the region.

It is not unheard of for Europe to be hit by the remnants of a hurricane. However, the storms typically travel west across the Atlantic Ocean in the Trade Winds and then re-curve to the northeast if they do not make landfall in the US, Mexico, or the Caribbean. Ophelia, however, skipped the transatlantic voyage and moved northeast toward Europe after forming southwest of the Azores.

Scientists say the storm’s rapid intensification and unusual track are the result of warmer than normal sea surface temperatures at northern latitudes and a steering current known as the mid-latitude jet stream. This current of air flows from west to east and carried the storm toward Ireland.

As the climate changes and sea surface temperatures continue to warm, the area of the ocean that supports hurricane development will likely expand northward. This will make Europe even more vulnerable to post-tropical storms.

MODIS satellite image of Ex-Hurricane Ophelia over Ireland. Credit: NASA

Hurricane Irma Batters Entire State of Florida

Hurricane Irma, the 9th named storm of this Atlantic Hurricane season, made two landfalls in Florida on Sunday. First, its eye crossed Cudjoe Key, just east of Key West, as a category-4 hurricane. Then, a few hours later,  it came ashore at Marco Island on the state’s Gulf Coast as a category-3 storm.

Measuring about 425 miles in diameter, Irma was wider than the Florida peninsula and its effects were felt across the entire Sunshine state. Powerful winds, heavy rain, and storm surge flooding caused catastrophic property damage in the Keys and along both coasts.

In the west, Naples, FL experienced wind gusts up to 142mph – the strongest recorded during the storm. On the east coast, gusts were clocked up to 109mph in the Miami/Fort Lauderdale area, where three high-rise construction cranes collapsed in the strong winds. The storm surge in both Biscayne Bay and Naples was about four feet above normal tide levels.  In the hard hit Keys, according to FEMA, 25% of homes were completely destroyed and about 65% sustained serious damage.

Reports of toppled trees and downed power lines are widespread. The Department of Homeland Security says 15 million people lost power, making it one of the largest power outages in US history.

Moving north and shifting inland, Irma was downgraded to a tropical storm on Monday. Nevertheless, it continued to pack a powerful punch. Jacksonville, FL reported a record six-foot storm surge and the worst flooding it has seen since Hurricane Dora moved through the area in 1964.

Irma’s wrath was also felt in parts of Georgia and the Carolinas. Along the coast, storm surge flooding inundated communities from Savannah, GA to Charleston, SC. Further inland, the NWS issued its first ever tropical storm warning for the metro-Atlanta area.

Coming just sixteen days after Hurricane Harvey, Irma was the second category-4 storm to make landfall in the US this season. In 166 years of record keeping, never before have two Atlantic hurricanes of such intensity hit this country during the same year.

The death toll from this historic storm currently stands at forty-three, including five fatalities reported in Florida, three in Georgia, and one in South Carolina. The rest are from the Caribbean, where Irma hit multiple islands as a Category 5 storm late last week. Sadly, these numbers are expected to rise as search and rescue efforts continue. The entire region faces a long and expensive road to recovery ahead.

Hurricane Irma makes landfall in southern Florida as a Category-4 storm. Credit: NASA

Hurricane Harvey Hammers Texas

Hurricane Harvey, the eighth named storm of the 2017 Atlantic Hurricane Season, made landfall in Rockport, TX late Friday night. It was the strongest storm to hit the United States in twelve years.

Coming ashore with winds measured up to 130mph, Harvey was classified as a Category-4 hurricane on the Saffir-Simpson Scale. These powerful winds along with storm surge flooding and torrential rain caused catastrophic property damage across the Texas Coastal Bend region. It also downed trees and left hundreds of thousands of people without power. To date, according to local officials, only two storm-related deaths have been reported.

Moving inland, toward Houston, Harvey weakened to a Tropical Storm on Saturday afternoon. However, despite this downgrade in wind speed, its rain bands are still drawing moisture from the Gulf of Mexico and unleashing massive amounts of precipitation. Wedged between two areas of high pressure, the storm is essentially stalled over the region. Therefore, even more flooding rain is expected over the next several days.

Harvey was the first major hurricane – category 3 or higher – to make landfall in the Lone Star State since Hurricane Carla in September 1961.

Satellite imagery from NOAA shows Hurricane Harvey along the Texas Coast. Credit: NOAA

Weather Lingo: The Brown Ocean Effect

Tropical cyclones are fueled by warm ocean water and typically peter out over land. Sometimes, however, their lives are extended by something called the “brown ocean effect”.

This is a phenomenon where a storm derives energy from the evaporation of abundant soil moisture deposited by previous rainfall. Essentially, the saturated soil mimics the role of the ocean allowing a tropical cyclone to maintain its strength or even intensify after making landfall.

For the brown ocean effect to occur, according to a NASA funded study by Theresa Andersen and Marshall Shepherd of the University of Georgia, three criteria need to be met:

  • The soil needs to contain copious amounts of moisture.
  • Atmospheric conditions near the ground must have tropical characteristics with minimal variation in temperature.
  • Evaporation rates must be high enough to provide the storm with sufficient latent heat that it uses for fuel, at least 70 watts averaged per square meter.

Although this process supplies less energy than the ocean, it is enough to sustain a storm for a longer period than normal over land. It was first noticed in 2007 after Tropical Storm Erin made landfall in Texas and then intensified as it traveled inland. It formed an eye over Oklahoma and unleashed a massive amount of rainfall.

Storms that are impacted by the brown ocean effect maintain a warm-core and are known as Inland Tropical Cyclone Maintenance and Intensification events (TCMIs). While rare, they are most common in the US, China, and Australia.

Credit: NBC/TWC

Weather History: Ten Year Anniversary of NYC’s Strongest Tornado

Ten years ago today, an EF2 tornado roared through New York City. It was the strongest twister on record to hit the Big Apple.

NYC Tornado of 2007. Credit: NYT

With winds measured up to 135 mph, it left a trail of destruction nine miles long from Staten Island to Brooklyn with the hardest hit neighborhoods being Bay Ridge and Sunset Park. The storm toppled trees and knocked out power to more than 4,000 customers. It damaged hundreds of cars and dozens of homes, including five that had their roofs ripped off. The storm also dumped 1.91 inches of rain in just one hour, which caused flash floods and the temporary suspension of subway service during the morning commute.

Historically, tornadoes have been rare events in NYC. In recent years, however, they have been happening more frequently. Of the eleven twisters that have touched down in the city since 1950, seven have occurred since 2003.

Note: Tornado ratings moved from the Fujita Scale (F) to the Enhanced Fujita Scale (EF) in 2007.

Tropical Storm Emily Soaks Florida’s Gulf Coast

Tropical Storm Emily, the fifth named storm of the 2017 Atlantic Hurricane Season, made landfall at Anna Maria Island in Tampa Bay, FL on Monday morning. It slammed the Sunshine state’s west coast with heavy rain and winds measured up to 45 mph.

According to the NWS, Valrico, FL, a few miles east of Tampa, saw 8.19 inches of rain. Widespread flooding was reported across the region and Gov. Rick Scott declared a state of emergency for 31 counties.

Most land-falling tropical storms come with a few days warning, as they develop over the ocean before moving toward populated areas. Emily, however, sprung up very quickly. It formed as the result of an out-of season cold front stalling out over the extremely warm waters of the Gulf of Mexico near Florida’s west coast.

Moving across the Florida peninsula, away from the warm waters that fueled it, the storm weakened quickly and was downgraded to a tropical depression. It is forecast to travel northeast out into the Atlantic Ocean. No major impacts are expected along the Eastern Seaboard, but rip currents will be an issue for beachgoers over the next few days from Florida to the Carolinas.

TS Emily moves over central Florida. Credit: NOAA/NASA GOES

Tropical Storm Cindy Batters Gulf Coast

Tropical Storm Cindy, the third named storm of the 2017 Atlantic Hurricane Season, made landfall between Cameron, LA and Port Arthur, TX early Thursday morning. It battered the area with heavy rain and winds measured up to 40 mph.

With rainbands spreading out across the Gulf Coast, flash floods were reported from New Orleans, LA to Pensacola, FL. The storm also downed trees and knocked out power to more than 32,000 customers across six states.

Moving inland, the storm was soon downgraded to a tropical depression. However, it still spawned a destructive tornado in Fairfield, AL. The NWS has given the twister a preliminary rating of EF-2.

The remnants of Cindy are expected to travel northeast over the next several days, unleashing even more torrential rain as it moves along.

Tropical Storm Cindy in the Gulf of Mexico. Credit: NOAA/NWS

Powerful Thunderstorm Lashes NYC

A violent thunderstorm lashed the New York City area on Monday afternoon. Strong winds and heavy rain were seen across the region.

After days of hot and humid conditions, a cold front moved in from the west and triggered these powerful storms. According to the NWS, 1.35 inches of rain was measured in Central Park and wind gusts reached 34 mph. Flash floods and downed trees were reported in Manhattan and the Bronx.

Below is a short video of the soaking rain seen near Madison Square Park in Manhattan.

Severe Thunderstorms: Watches vs Warnings

A severe thunderstorm is forecast for the New York City area on Monday afternoon. In addition to lightning, it could bring strong winds, heavy rain, hail, and the possibility of a tornado. Simply put, this is the type of weather that can cause property damage and loss of life. Therefore, it is important to understand the difference between the various alerts issued by the National Weather Service. They include advisories, watches, and warnings.  All should be taken seriously.

  • Advisory: Issued when significant, but not necessarily hazardous, weather conditions are likely to occur. Residents should exercise caution.
  • Watch: Issued when dangerous weather conditions are possible over the next several hours.  They generally cover a large geographic area.  Residents should be prepared to take action.
  • Warning: Issued when dangerous weather is imminent or already occurring.  They cover a smaller, more specific geographic area.  Residents should take action immediately.

Names for the 2017 Atlantic Hurricane Season

Today is the first day of the Atlantic Hurricane Season. Although one named storm – TS Arlene – already formed this year, the season officially runs from June 1st to November 30.

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.

2017 Atlantic Storm Names

ArleneHarvey
Ophelia
BretIrmaPhilippe
Cindy
JoseRina
DonKatiaSean
Emily
LeeTammy
FranklinMariaVince
GertNateWhitney