Earth Posts Third Warmest August and Summer on Record

Our global temperature continued its upward trend last month. August 2017 marked not only the third warmest August on record but also closed out the planet’s third warmest June to August period, which is known as meteorological summer in the northern hemisphere.

According to the State of the Climate report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for August – over both land and sea surfaces – was 61.59°F, which is 1.49°F above the 20th-century average. Only August 2015 and 2016 were warmer.

This August also marked the 392nd consecutive month with a global temperature above its long-term norm. That means the last time any month posted a below average reading was December 1984.

The three-month period of June, July, and August was also unusually warm. NOAA reports that Earth’s average temperature for the season was 1.46°F above the 20th century average of 60.1°F. That makes it the third warmest such period on record, trailing only the 2016 and 2015 seasons.

While heat dominated most of the planet this summer, some places were particularly warm, including parts of Europe, the Middle East, and the western United States. For the contiguous US as a whole, it was our fifteenth warmest summer on record.

These soaring temperatures are largely attributed to the long-term trend of human-caused climate change. ENSO-neutral conditions prevailed in August, which means there was neither an El Niño nor a La Niña in the Pacific to influence global weather patterns.

Year to date, the first eight months of 2017 were the second warmest such period of any year on record. Global temperature records date back to 1880.

Credit: NOAA

Climate Week NYC 2017

Climate Week NYC begins on Monday.

This annual global summit takes place alongside the UN General Assembly and brings together leaders from a variety of sectors, including business, government, and civil society, to discuss climate change. Organized by The Climate Group since 2009, the goal of the conference and its affiliate events is to raise awareness and keeping climate action at the top of the global agenda. This year’s event will focus on the implementation of the Paris Climate Agreement and UN sustainable development goals.

Public events in support of the summit’s mission are scheduled all week around the city, from September 18-24. They range in style from panel discussions and seminars to concerts and exhibitions. For the full program of events, go to the Climate Week website.

Credit: The Climate Group

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 Irma Challenges Multiple Records

Hurricane Irma’s final chapters have yet to be written, but the storm has already earned its place in the history books.

According to NOAA, Irma’s winds peaked at 185 mph. That means it is tied as the second strongest hurricane ever recorded in the Atlantic Basin. It shares this dubious honor with the Labor Day /Florida Keys Hurricane of 1935, Hurricane Gilbert of 1988, and Hurricane Wilma of 2005. Only Hurricane Allen in 1980 was stronger with winds clocked at 190 mph. That said, Irma now ranks as the strongest storm on record in the Atlantic outside of the Carribean Sea and the Gulf of Mexico.

Irma’s winds remained at 185 mph for 37 hours. That is the longest any storm on the planet has maintained that level of intensity. The previous record of 24 hours was set by Super Typhoon Haiyan in the northwest Pacific in 2013. Furthermore, Irma remained a Category 5 hurricane for three consecutive days, the longest such measurement since the satellite era began in 1966.

Source: NHC

NYC Monthly Summary: August 2017

August was unusually mild in New York City this year. Of the month’s thirty-one days, nineteen posted below average readings, including an unseasonably cool 68°F on August 29. Furthermore, the month typically produces four days with readings in the 90s, but this year we only had one. In the end, the city’s mean temperature for the month was 74°F, which is 1.2°F below average.

In terms of precipitation, August was mostly dry. Overall, 3.34 inches was recorded in Central Park, marking the fourth month this year and second in a row to deliver below average rainfall. The city usually gets 4.44 inches of rain for the month.

August 2017 was unusually mild in NYC. Credit: The Weather Gamut

Harvey Sets New Rainfall Record for Continental US

Battering southeast Texas for days, Tropical Storm Harvey has produced more rainfall than any other single storm on record in the contiguous United States.

According to the NWS, 51.88 inches of rain was reported at a gauge near Mont Belvieu at Cedar Bayou, about 40 miles east of Houston. This crushes the previous record of 48 inches that was set by Tropical Storm Amelia which hit Medina, TX in 1978.

The record for the entire US, however, still stands. It was set in 1950 when Hurricane Hiki dropped 52 inches of rain on Hawaii.

Source: NWS

Harvey Unleashes Catastrophic Flooding in Houston

Days after making landfall as a category-4 hurricane, Harvey, now a tropical storm, is still battering southeast Texas. Relentless rain has unleashed catastrophic flooding across the region, including Houston – this country’s fourth largest city.

While this devastating event is still unfolding, rainfall totals in some areas have already exceeded two feet. Dayton, TX, northeast of Houston, has reported a staggering 39.72 inches of rain since Thursday. Houston Intercontinental Airport (IAH) has posted 25.66 inches of rain so far and reported its wettest calendar day on record on Sunday with 16.07 inches.

This intense rainfall is causing the many rivers, creeks, and bayous in the metro Houston area to overflow their banks and flood homes, businesses, and major roadways – effectively paralyzing the area. Rainfall rates reached as high as 3 inches per hour on Sunday in some areas, prompting the NWS to issue a flash flood emergency – the highest level of a flood alert.

No evacuation order was issued ahead of the storm in Houston and residents were told to shelter in place. Now, thousands of high water rescues are taking place via boat and helicopter to save people trapped in their homes. The situation has many people comparing it to scenes that played out in the aftermath of Hurricane Katrina in New Orleans. The mayor of Houston, Sylvester Turner, has opened the massive George R. Brown Convention Center to be used as a shelter. As of Monday, eight storm-related deaths have been reported. But sadly, local authorities expect this number to increase as the water continues to rise.

Southeast Texas is no stranger to flooding. However, officials in Houston say this event is the worst they have seen since Tropical Storm Allison in 2001. That storm dumped more than 35 inches of rain on the metro area over the course of five days and caused $5 billion worth of damage.

Harvey, wedged between two areas of high pressure, is expected to linger over the region for several more days and dump an additional 15 to 25 inches of rain. Forecasters at the NWS say the rainfall total for this storm could reach an unprecedented 50 inches in some spots.

Eighteen counties in Texas, according to Governor Greg Abbot, have been declared federal disaster areas because of this storm.

TS Harvey caused unprecedented flooding in Houston, TX. Credit: Aryan Midas

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

Solar Eclipse Cools NYC by Nearly 4°F

Monday marked the first time in decades that a total solar eclipse was visible in the continental US. The path of totality was about 70 miles wide and passed through 14 states, from Oregon to South Carolina. The rest of the country, however, saw varying degrees of a partial eclipse.

Partial Solar Eclipse 2017 seen from NYC. Credit: Melissa Fleming

Here in New York City, the magnitude was only about 72%. Nonetheless, this celestial event had a noticeable impact on the local temperature. Our weather station in mid-town Manhattan showed a drop of 3.7°F as the moon briefly obscured the afternoon sun.

The next solar eclipse that will be visible from the east coast will take place on April 8, 2024. So, hold on to those eclipse viewing glasses!

The solar eclipse peaked at 2:44 PM EDT in NYC. Credit: The Weather Gamut