Will Hurricane Irene Wreck The East Coast?

Update: just as we post this we see the following report from Reuters:

U.S. says Irene could be "big threat" to northeast


Powerful Hurricane Irene could pose a "big threat" to the densely populated northeast United States, including New York, as it swings up the eastern seaboard from Saturday on its current forecast track, the top U.S. government hurricane forecaster said on Wednesday.


National Hurricane Center Director Bill Read gave the warning as Irene, now a major Category 3 storm with winds of 115 miles per hour, roared through the Bahamas on a path that will take it to the U.S. East Coast by the weekend.


As it swept over the southeastern Bahamas, its winds tore off home roofs and knocked out power, authorities reported.


Some tourists fled Nassau and other resorts in the low-lying Atlantic archipelago, while others hunkered down in hotels, and cruise lines canceled their Bahamas stops for the next few days.


Forecasters see the first hurricane of the 2011 Atlantic season, turning north from Thursday to miss Florida and Georgia and clip North Carolina's Outer Banks region on Saturday afternoon. Irene is then seen taking a coast-hugging track up the U.S. mid-Atlantic and New England coastline.


States from the Carolinas northward were on alert and evacuations were already underway in some of North Carolina's most exposed Outer Banks barrier islands, such as Ocracoke.

Earlier today, Hurricane Irene was upgraded by the National Hurricane Center to category 3 as it passed above the Turks and Caicos, preemptively ending the holidays for quite a few Wall Streeters taking a well-deserved break from chasing levered beta. So admitting we know nothing about predicting the weather, we present the following update from Jeff Masters' Weather Underground blog.

First, here is his general update on the storm slowly approaching the Eastern Seaboard:

Powerful Category 3 Hurricane Irene stormed through the Turks and Caicos Islands overnight, bringing hurricane-force winds, torrential rains, and storm surge flooding. On Providenciales in the Turks and Caicos Islands, where half of the population of these islands live, winds reached a sustained 65 mph at a personal weather station at Pine Cay, and the pressure bottomed out at 989 mb. The eyewall of Irene missed the island, with the center of the storm passing about 60 miles to the southwest. The center of Irene passed about 60 miles to the northwest of Grand Inagua Island, and Category 1 hurricane conditions were probably experienced on that island. Damage in the Turks and Caicos is likely to be much less than the $50 - $200 million wrought by Category 4 Hurricane Ike of 2008, since Irene's eyewall missed populated islands.


Monday, Irene hit Puerto Rico as a tropical storm with 70 mph winds, but reached hurricane strength as it emerged into the Atlantic northwest of the capital of San Juan. One drowning death is being reported from the island, and the storm dumped up to 20 inches of rain in some areas. About 11% of the island was still without power this morning, and numerous roads were closed due to flooding and landslides. Irene did an estimated $17 million in damage to agriculture and $2 million to ports in Puerto Rico. Satellite estimates suggest that Irene has brought only 1 - 2 inches of rain to Haiti. With Irene now pulling away from Hispaniola, Haiti can expect only another 1 - 2 inches from the hurricane, and appears to have dodged a major bullet. Heavy rains of 3 - 6 inches were common across the Dominican Republic, where moderate flooding but no deaths occurred.

Figure 1. Morning satellite image of Irene. 


Track forecast for Irene


Continuing dropsonde missions by the NOAA jet have helped to significantly narrow the uncertainty in the 1 - 3 day forecasts from the computer models. Irene will track through the central Bahamas today, the northwestern Bahamas on Thursday, and approach the Outer Banks of North Carolina on Friday. However, the models still diverge considerably on their 4 - 5 days forecasts, and we don't know if Irene will plow up the mid-Atlantic coast into New Jersey, as the GFDL model is predicting, hit New England between Long Island, NY and Massachusetts, as the ECMWF, GFS, and HWRF models are predicting, or miss the U.S. and hit Canada, as the NOGAPS model is predicting.


Intensity forecast for Irene
Latest data from the Hurricane Hunters shows that Irene has paused in its intensification cycle. A gap has opened in the eyewall, and the central pressure has remained constant at 956 - 957 mb over the past few hours. However, the hurricane is embedded in a large envelope of moisture, and wind shear is expected to remain low to moderate, 5 - 20 knots, for the next three days. With water temperatures very warm, 28 - 30°C, these conditions should allow for intensification to a Category 4 storm sometime in the next two days. Satellite loops show that Irene is well-organized, with excellent upper-level outflow, and impressive spiral banding.

And here is the key update on what is coming to New York:

Irene's impact on the mid-Atlantic and New England 


The impact of Irene on the mid-Atlantic and New England is highly uncertain at this point, because we don't know if the core of the storm will miss the coast or not. In general, the heaviest rains will fall along a 100-mile swath just to the west of where the center tracks, and the worst wind and storm surge damage will occur to the east. If the core of Irene stays offshore, the mid-Atlantic and New England may escape with a few hundred million dollars in damage from flooding due to heavy rains and storm surge. If Irene hits Long Island or Southeast Massachusetts, the storm has the potential to be a $10 billion disaster. Irene is one of those rare storms that has the potential to make landfall in New England as a Category 2 or stronger hurricane. It is difficult for a major Category 3 or stronger hurricane crossing north of North Carolina to maintain that intensity, because wind shear rapidly increases and ocean temperatures plunge below the 26°C (79°F) level that can support a hurricane. We do expect wind shear to rapidly increase to a high 30 - 50 knots once Irene pushes north of Delaware, which should knock the storm down by at least 15 - 30 mph before it reaches New England. However, this year sea surface temperatures 1 - 3°F warmer than average extend along the East Coast from North Carolina to New York. Waters of at least 26°C extend all the way to Southern New Jersey, which will make it easier for Irene to maintain its strength much farther to the north than a hurricane usually can. During the month of July, ocean temperature off the mid-Atlantic coast (35°N - 40°N, 75°W - 70°W) averaged 2.6°F (1.45°C) above average, the second highest July ocean temperatures since record keeping began over a century ago (the record was 3.8°F above average, set in 2010.) These warm ocean temperatures will also make Irene a much wetter hurricane than is typical, since much more water vapor can evaporate into the air from record-warm ocean surfaces. The latest precipitation forecast from NOAA's Hydrological prediction center shows that Irene could dump over 8 inches of rain over coastal New England.

Well, if the expert says he has no idea what is going to happen we could keep our mouth shut, or pull a Dick Bove and claim that the storm will be hugely beneficial for the Tri-State area, knowing absolutely nothing about anything, while advising anyone dumb enough to listen that selling Kansas Torando insurance is the guaranteed to make one wealthy beyond their wildest dreams.