# 4617
There are environmental and climatological factors that we know influence hurricane development – sometimes dampening formation and sometimes exacerbating it.
Right now, the ingredients for an active hurricane season appear to be either in place, or on the horizon. While conditions could change, right now:
Sea surface temperatures are at historic levels, the El Nino in the Pacific - which curtailed hurricane formation last year - is on its way out, and a La Nina – which is conducive for Atlantic tropical cyclone genesis appears likely to set in over the next couple of months.
Every year (since the mid-1980s) the Colorado State University hurricane forecast team, under the direction of Dr. William Gray, has issued hurricane season outlooks. These outlooks begin in the winter, and are updated every couple of months.
Today, CSU’s team has increased its predictions over the `above-average’ season they were calling for in April. Last week NOAA their own forecast, also calling for a very active season (see NOAA 2010 Atlantic Hurricane Outlook).
Colorado State University Hurricane Forecast Team Increases Prediction, Calls for Very Active 2010 Hurricane Season
FORT COLLINS - The Colorado State University hurricane forecast team today increased its predictions and is now calling for a very active 2010 season in the Atlantic basin with 18 named storms predicted. The forecast was based on much warmer-than-normal tropical Atlantic sea surface temperatures and cooling tropical Pacific conditions that will likely transition into a weak La Nina by mid-season.
Of the 18 storms, the team now anticipates 10 hurricanes forming in the Atlantic basin between June 1 and Nov. 30. Five are expected to develop into major hurricanes (Saffir/Simpson category 3-4-5) with sustained winds of 111 mph or greater.
The scientists increased their forecast from April's prediction of 15 named storms, eight hurricanes and four major hurricanes. Long-term (1950-2000) averages are 9.6 named storms, 5.9 hurricanes and 2.3 major hurricanes per year.
“We have increased our forecast from early April, due to a combination of a transition from El Nino to current neutral conditions and the continuation of unusually warm tropical Atlantic sea surface temperatures,” said William Gray, who is in his 27th year of forecasting at Colorado State. “We anticipate a well above-average probability of United States and Caribbean major hurricane landfall.”
The team also updated its U.S. landfall probabilities, which are calculated based on historical landfall statistics and then adjusted by the latest seasonal forecast.
"The probability of a major hurricane making landfall along the U.S. coastline is 76 percent compared with the last-century average of 52 percent," said lead forecaster Phil Klotzbach. “We expect that the current trend from El Nino to neutral conditions will persist and that weak La Nina conditions will develop by the most active portion of this year’s hurricane season (August-October).
The team will issue a final seasonal forecast update on Wednesday, August 4.
CSU RESEARCH TEAM
EXTENDED RANGE ATLANTIC BASIN HURRICANE FORECAST FOR 2010
-Released June 2, 2010-
Tropical Cyclone Parameters Extended Range
(1950-2000 Climatology Averages Forecast for 2010
in parentheses)
Named Storms (9.6)* 18
Named Storm Days (49.1) 90
Hurricanes (5.9) 10
Hurricane Days (24.5) 40
Intense Hurricanes (2.3) 5
Intense Hurricane Days (5.0) 13
Accumulated Cyclone Energy (96) 185
Net Tropical Cyclone
Activity (100%) 195
* Numbers in ( ) represent average year totals based on 1950-2000 data.
