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

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

June 2017: A Temperature Roller Coaster in NYC

June 2017 felt like a temperature roller coaster in New York City. Highs ranged from an unseasonably cool 58°F to a balmy 94°F. June also brought the city its second heat wave of the year. In the end, however, the cold and warmth balanced each other out. The city’s mean temperature for the month was 72°F, which is only .06°F above average.

 

In terms of precipitation, the city was wetter than normal. Overall, 4.76 inches of rain was measured in Central Park. Of this total, 84% fell during three separate heavy rain events that each produced over an inch of rain. On average, the Big Apple gets 4.41 inches of rain for the entire month of June.

Credit: The Weather Gamut

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.

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

Unseasonable Nor’easter Soaks NYC

An unseasonable nor’easter soaked the northeastern US this Mother’s Day weekend. Heavy rain and gusty winds were reported across the region.

Here in New York City, 1.61 inches of rain fell in Central Park. This impressive total was only a few one-hundredths on an inch shy of the daily record of 1.66 inches that was set in 1971.

This storm also marked the second consecutive wet weekend for the Big Apple. Last Friday, a record-shattering 3.02 inches of rain came down in just a few hours. Between these two storms, the city has already received more precipitation than it typically sees for the entire month of May.

With an area of low pressure intensifying as it traveled north along the Atlantic coast, this storm was a textbook nor’easter. While this type of storm is more common during the fall and winter months, they can develop any time of the year.

Satellite view of the unseasonable May nor’easter. Credit: NOAA