Contact: Carmeyia Gillis
FOR IMMEDIATE RELEASE
301-763-8000, ext, 7163 Aug. 7, 2008
Strong Start Increases NOAA’s Confidence for Above-Normal Atlantic Hurricane Season
In the August update to the Atlantic hurricane season outlook, NOAA’s Climate Prediction Center has increased the likelihood of an above-normal hurricane season and has raised the total number of named storms and hurricanes that may form. Forecasters attribute this adjustment to atmospheric and oceanic conditions across the Atlantic Basin that favor storm development – combined with the strong early season activity.
NOAA now projects an 85 percent probability of an above-normal season – up from 65 percent in May. The updated outlook includes a 67 percent chance of 14 to 18 named storms, of which seven to 10 are expected to become hurricanes, including three to six major hurricanes of Category 3 strength or higher on the Saffir-Simpson Scale. These ranges encompass the entire season, which ends November 30, and include the five storms that have formed thus far.
In May, the outlook called for 12 to 16 named storms, including six to nine hurricanes and two to five major hurricanes. An average Atlantic hurricane season has 11 named storms, including six hurricanes and two major hurricanes.
“Leading indicators for an above-normal season during 2008 include the continuing multi-decadal signal – atmospheric and oceanic conditions that have spawned increased hurricane activity since 1995 – and the lingering effects of La Niña,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center. “Some of these conditions include reduced wind shear, weaker trade winds, an active West African monsoon system, the winds coming off of Africa and warmer-than-average water in the Atlantic Ocean.”
Another indicator favoring an above-normal hurricane season is a very active July, the third most active since 1886. Even so, there is still a 10 percent chance of a near normal season and a five percent chance of a below normal season.
NOAA’s hurricane outlook is a general guide to the expected level of hurricane activity for the entire season. NOAA does not make seasonal landfall predictions since hurricane landfalls are largely determined by the weather patterns in place as a hurricane approaches.
Five named storms have formed already this season. Tropical Storm Arthur affected the Yucatan Peninsula in late May and early June. Bertha was a major hurricane and the longest-lived July storm (July 3-20) on record. Tropical Storm Cristobal skirted the North Carolina coastline. Dolly made landfall as a Category 2 hurricane at South Padre Island, Texas on July 25. And on August 5, Tropical Storm Edouard struck the upper Texas coast.
“It is critical that everyone know the risk for your area, and have a plan to protect yourself, your family and your property, or to evacuate if requested by local emergency managers. Be prepared throughout the remainder of the hurricane season,” Bell said. “Even people who live inland should be prepared for severe weather and flooding from a tropical storm or a hurricane.”
The Atlantic hurricane season includes activity over the Atlantic Ocean, Caribbean Sea and Gulf of Mexico. The peak months of the season are August through October.
NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources. Visit http://www.noaa.gov
On the Web:
NOAA’s National Weather Service: http://www.weather.gov
NOAA’s Climate Prediction Center: http://www.cpc.ncep.noaa.gov
Updated 2008 Atlantic Hurricane Outlook:
http://www.cpc.ncep.noaa.gov/products/outlooks/hurricane
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What I’ve noticed is that NOAA is naming any cluster of thunder storms and calling it a ‘tropical’ storm even though it forms well above the tropics. for a time they used the term ‘sub-tropical’ now they just tack the next alphabetical name and give it a reason for alarm and the ratings pimp weather guys just thank them and go live to a shower in Texas.
BarryW (20:29:18) :
“I’ve wondered about the inhibiting effect of previous activity relative to later storms. If storm convection effectively sucks the energy out of the sea surface, could early storms … be used as predictors for late season storms?”
I don’t think they’re used as such, but a storm’s passage does leave cooler water in its wake. Both evaporation and mixing of the ocean column are culprits. In the short term, a storm that stalls will be forecasted to weaken due to SST cooling.
The empirical and analog forecasting Gray & associates use does take that into account indirectly – if the current season looks similar to a previous season, then expectations are that the two will be similar. So any suppression due to activity in the previous system is carried forward into the current season.
A story in Science News is loosely related to hurricanes, so I’ll post it here. It’s more related to incomplete climate models.
http://www.sciencenews.org/view/generic/id/35023/title/Forecast_Gullywashers says in part:
Their comment system doesn’t like me today, I tried to add:
My guess is that if the modelers fix that, they’ll increase the CO2 feedback factor since that was set to make the projections match the temperature rise over the last few decades. Or however it is that they set it. At any rate, the result may be a wash for recent temperatures, perhaps a bit of reduction in their projections forward.
I was looking at the hurricane center’s website yesterday, and not only was the Atlantic compleatly empty of cyclonic acction, there wasn’t even an area marked as likely to seed cyclonic acction. So far it seems to me that this has been a quiet hurricane season.
I’ev noticed here in Oz that low altitude snow is now called ‘soft hail’
Doug (22:46:30) :
“What I’ve noticed is that NOAA is naming any cluster of thunder storms and calling it a ‘tropical’ storm even though it forms well above the tropics. for a time they used the term ’sub-tropical’ now they just tack the next alphabetical name …”
The terms tropical, subtropical, and extratropical refer to a storm’s structure, not to any location along its track. Subtropical storms tend to start as a broad area of thunderstorms linked by a large low pressure area. The Weather Underground has a very good writeup at http://www.wunderground.com/hurricane/subtropical.asp . Subtropical storms can “grow up” into tropical storms, but they can be named before that.
Subtropical storms that eat up names and never become tropical storms are a bit awkward for the longterm tropical storm forecasts, since the count of named storms no longer matches the count of tropical storms, Gray and co. have groused about that a bit and claim that the NHC has been too quick and inconsistant about assigning names to subtropical storms.
Joe Bastardi, Accuweather’s hurricane capo, has long pointed out that total number of storms, while interesting in the abstract, is not the crucial figure for tropical cyclone impact, except, perhaps, for schools of fish; rather, it is the number and tracks of landfalling storms that is important.
Is this the year that at least one major hurricane affects the east coast from Hatteras north? Or how about four such storms in a month a la 1954, during the last maturing phase of the AMO? Imagine what the Gang would make of that? Hurricane Carol did to Providence, Rhode Island what Katrina did to New Orleans. The center of Hazel, in October, passed 80 miles west of New York City, but produced a sustained wind at the Battery of 115 mph, still the official record for the city.
Or how about Hurricane Donna in September of 1960, the only storm on record to produce hurricane conditions onshore in every state from Florida (both coasts) to Maine?
Deja vu? ‘We have all been there before.’
By the way, once again I have been cheated! Arthur huffed and puffed its way up to 39 mph for a couple of hours wasted the name. I wish I were an Andrew.
‘So far it seems to me that this has been a quiet hurricane season.’
But here comes the MJO, just in time for the heart of the season.