Irene's 1-in-100 year rains trigger deadly flooding

[phantom power]

Hurricane Irene is gone, but the huge hurricane's torrential rains have unleashed one of the Northeast's greatest flood disasters. Videos of rampaging rivers in Vermont, New York State, New Jersey, and surrounding states attest to the extreme nature of the great deluge Hurricane Irene brought. Numerous rivers and creeks throughout the Northeast crested above their highest flood stages on record over the past 24 hours. The previous records were mostly set during some of the great hurricanes of 50 - 60 years ago--Hazel of 1954, Connie and Diane of 1955, and Donna of 1960. Vermont, where 3 - 7 inches of rain fell in just twelve hours, was particularly hard-hit. Otter Creek in Rutland, Vermont crested at 17.21 feet, 3.81' above its previous record, and more than 9 feet above flood stage. In northern New Jersey and Southeast New York, where soils were already saturated from the region's wettest August on record even before Irene arrived, record flooding was the norm. According to imagery from metstat.com, Irene's rains were a 1-in-100 year event for portions of six states.


Here are a few of the rivers in the Northeast that set all-time flood height records over the past 24 hours, which I found using our wundermap with the USGS rivers layers turned on:

Mettawee River, Middle Granville, NY
Hoosic River, North Bennington, VT
Saxton River, Saxtons RIver, VT
Schoharie Creek, Gilboa, NY
Esopus Creek, Coldbrook, NY
Passaic River, Millington, NJ
Rockaway River, Boonton, NJ
Pompton River, Pompton Plains, NJ
Millstone RIver, Blackwells Mills, NJ
Assunpink Creek, Trenton, NJ

And here are the unofficial maximum 24-hour rainfall amounts each state received from Irene, as compiled by our weather historian, Christopher C. Burt:

North Carolina: 14.00" Bunyan
Virginia: 12.52" Ft. Eustis
Maryland: 12.96" Plum Point
Delaware: 8.50" Federalsburg
Pennsylvania: 8.00" Goldsboro
New Jersey: 10.20" Wayne
New York: 11.48" Tuxedo Park
Connecticut: 8.70" Burlington
Massachusetts: 9.10" Savoy
Vermont: 7.60" Walden
New Hampshire: 6.09" 5SE Sandwich
Rhode Island: 5.37" Warren
Maine: 6.11" Phillips

Newark, NJ broke its all-time 24-hour precip record with a total of 8.92" (8/27-28)--old record 7.84" on 8/27-28/1971. Also, New York City, Philadelphia, and Newark now have August 2011 as their rainiest month in recorded history. Overall damages from Irene could range from $5 billion to $10 billion, according to Kinetic Analysis, a risk assessment firm that specializes in natural disaster impact. This would put Irene between 13th and 24th place on the list of the most damaging hurricanes ever to hit the U.S. Irene is very likely to have its name retired. The multi-billion dollar price tag from Irene puts the year 2010 in first place for the greatest number of billion-dollar disasters in one year, ten. The previous record was nine such disasters, set in 2008.

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1908

[saras]

1. This also demonstrates the failure of the "Cat 1-6" system for measuring them.

Clearly, maximum wind speed is not sufficient criteria to make good decisions about the potential damage caused by a storm. Hopefully our current system of trying to replace the missing data with media hysteria can be replaced by fact-based warnings of likely consequences. It appears at first glance that people overprepared for wind and underprepared for flooding. The NOAA did a marvelous job providing good data, so it's not something that can't be done.

[phantom power]

2. There have been some proposals to better capture total storm energy and consequences.

One issue that ought to be addressed is that the large majority of all hurricane/TS damage is from rain or storm surge. Irene has turned out to be a textbook example.

[pscot]

3. Lucky it only happens

once every hundred years.

[rurallib]

5. we have had 2 of those once in a hundred year cycles

in the past 16 years.
Like a hundred bucks, a hundred years don't last nearly as long as they used to.

Actually, one was a once in 500 year cycle.
This is eastern Iowa. Now the western part of the state is getting another 'once in a hundred year' cycles. I think this is their 3rd in 20 years. I am losing track any more.

[obama14]

4. NJ was hit very hard.

Here is in NJ it was very bad. A lot of towns you couldn't get around unless you had a Jet Ski. Oddly it was the inland towns more then the Jersey Shore.

It will be in the billions of dollars in water damage.

[Pooka Fey]

6. Thanks for posting these tables, Phantom Power. n/t