Government scientists on Thursday reduced their forecast for the 2010 Atlantic-Caribbean hurricane season, but said they were still predicting a very active year of eight to 12 hurricanes.
The National Oceanic and Atmospheric Administration said it now expects 14 to 20 tropical storms, with eight
to 12 of those strengthening into hurricanes.
It forecast that four to six of them would become "major" hurricanes, which are ranked at Category 3 or above on the five-step Saffir-Simpson scale of intensity and have top winds of more than 110 miles per hour (177 km per hour).
The revision reflected the lower-than-expected number of storms that developed in June and July.
"We're still predicting a very active hurricane season and it's very important that people understand that," said Gerry Bell, the lead hurricane seasonal forecaster with NOAA's Climate Prediction Center.
The 2O10 season has seen three tropical storms so far, with only one reaching hurricane strength.
The season is just nearing its traditionally most active phase, which runs from mid-August through October. Hurricanes feed on warm water and the tropical Atlantic is warmest during that time.
LA NINA IMPACT
NOAA also announced today that, as predicted last spring, La Niña has formed rapidly in the tropical Pacific Ocean. This favors lower wind shear over the
Atlantic Basin, allowing storm clouds to grow and organize.
Other climate factors pointing to an active hurricane season are warmer-than-average water in the tropical Atlantic and Caribbean, and the tropical multi-decadal signal, which since 1995 has brought favorable ocean and atmospheric conditions in unison, leading to more active seasons.
"I'm not sure I'd say (it's) unusually strong," Bell said. "This is not a record type of event by any means but it's a La Nina that's already having impact."
The Atlantic is already in the midst of an active hurricane period that began in 1995 and could last another decade or two.
When La Nina forms during such a period, "that sets up just a perfect environment for these systems to form and strengthen," Bell said.
In its pre-season forecast, NOAA had said the 2010 season could rival the record-busting 2005 season that brought 28 storms, including Hurricane Katrina (left)that killed more than 1,500 people, flooded New Orleans and wreaked havoc on energy production in the Gulf of Mexico.
That seemed less likely now, but still "everything is in place for a very active year," Bell said.
Source:
Reuters,"NOAA trims hurricane outlook, still seen very active", accessed August 5, 2010
Last month was the warmest May on record, the U.S. National Oceanic and Atmospheric Administration said on Tuesday in its regular monthly analysis based on records that go back to 1880.
It was also the 303rd consecutive month that was hotter than the 20th century global average for that month, according to Deke Arndt, chief of the climate monitoring at NOAA's National Climatic Data Center.
"Since February 1985, every single month has been warmer than its 20th century average," Arndt said by telephone from Asheville, North Carolina.
The long-term warming trend, along with reports that Arctic sea ice covered less of the ocean and snow covered less ground around the world in May, is consistent with the science of climate change, Arndt said.
Many climate scientists believe that Earth's surface is warming, due in part to the emission of heat-trapping greenhouse gases, including carbon dioxide.
In addition to a record-hot May, high temperature surface records -- for warmth on the planet's land and oceans -- were set for the period of March through May and for January through May, the data center said in a statement.
Looking only at global average land surface temperatures, May and the March-to-May period were also the warmest on record.
Global ocean surface temperatures for both May and March-to-May were the second-hottest on record, behind 1998, according to the data center.
The combined global land and ocean surface temperature for May was 59.84 degrees F (15.46 C), which was 1.24 degrees F (0.69 degrees C) above the 20th century average of 58.6 degrees F (14.8 degrees C).
The global land surface temperature for May was 53.87 degrees F (12.15 degrees C), which is 1.87 degrees F (1.04 degrees C) above the 20th century average of 52 degrees F (11.1 degrees C) -- the warmest on record.
The May worldwide ocean temperature, the second warmest ever recorded after 1998, was 62.29 degrees F (16.82 C), compared to the 20th century average of 61.3 degrees F (16.3 degrees C).
Most of Earth's land areas saw extraordinary warm temperatures, with 
the hottest showing up in eastern North America, eastern Brazil, eastern Europe, southern Asia, eastern Russia, and equatorial Africa. China's Yunnan province had its warmest May since 1951 while many locations in Ontario, Canada had their warmest May on record.
It was unusually cool across western North America, northern Argentina, interior Asia and Western Europe. Germany had its coolest May since 1991, its 12th coolest May on record.
To review the actual NOAA report, keep reading here.
Source:
Reuters, "May 2010 was warmest on record: U.S. government data", accessed June 16, 2010
to 12 of those strengthening into hurricanes.
"We're still predicting a very active hurricane season and it's very important that people understand that," said Gerry Bell, the lead hurricane seasonal forecaster with NOAA's Climate Prediction Center.
Atlantic Basin, allowing storm clouds to grow and organize.
