Category 4 Joaquin Pounds the Bahamas; a U.S. Landfall Unlikely - Jeff Masters

[malaise]

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=3136
<snip>
Dangerous Hurricane Joaquin has intensified to a Category 4 storm with 130 mph winds and a 936 mb pressure, making it the strongest Atlantic hurricane in five years. The last stronger storm was Hurricane Igor of 2010, which bottomed out at 924 mb on September 15, 2010. Joaquin is now the second major hurricane of 2015 in the Atlantic, joining Hurricane Danny, which peaked as a Category 3 storm with 115 mph winds on August 21. Joaquin's motion has slowed to a 5 mph westward crawl over the Central Bahamas, which are receiving an epic pounding from the mighty hurricane. David Adams of Reuters told me this afternoon that he has been calling down to the Bahamas, and no phones are being answered on Aklins Island--but Reuters' Nassau correspondent informed him that flooding was bad on Aklins Island and Long Island. The last hurricane hunter aircraft departed the storm after a 12:47 pm EDT eye fix, and new plane will be in the storm early this evening. The Hurricane Hunters found that Joaquin's eye had shrunk from 41 miles in diameter early this morning to 27 miles in diameter this afternoon. Shrinkage of the eye is common in intensifying major hurricanes, and eyewall replacement cycles that lead to temporary weakening of the storms typically occur when the eye diameter gets down to about 10 miles. Wind shear continued to be in the moderate range, 10 - 20 knots, on Thursday afternoon, and visible and infrared satellite loops showed that Joaquin was a moderate-sized hurricane with impressive organization, with a solid core of intense eyewall thunderstorms surrounding a clear eye. Upper level wind analyses from the University of Wisconsin show that the hurricane has maintained an impressive upper-level outflow channel to the southeast, and it appeared a new outflow channel was ready to open up to the northwest, which would support continued intensification. Ocean temperatures in the region remain a record-warm 30°C (86°F), but may start to cool due to Joaquin's slow motion. This cooling of the waters could well put the brakes on further intensification by Friday morning.


Two major Atlantic hurricanes during a strong El Niño: a first
Strong El Niño conditions currently exist in the Eastern Pacific, where ocean temperatures have warmed to 2.3°C above average in the region 5°N-5°S, 120°W-180°W (called the Niño 3.4 region). Major hurricanes are uncommon when ocean temperatures get this warm in the Eastern Pacific, and 2015 is the first strong El Niño year to experience two major Atlantic hurricanes since El Niño records began in 1950. The other four years that had strong El Niño conditions during the peak August-September-October portion of hurricane season have had only one major hurricane each. Those years were 1972, 1982, 1987, and 1997. Joaquin is now the second strongest Atlantic hurricane observed during strong El Niño conditions, behind only Hurricane Debby of 1982, which had 135 mph winds.