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Bill Gray's latest hurricane season forecast

By: Dr. Jeff Masters, 3:15 PM GMT on May 31, 2006

The latest 2006 Atlantic hurricane season forecast from the forecast team at Colorado State University (CSU) was issued today. Phil Klotzbach and Dr. Bill Gray's forecast is unchanged from their earlier April 4 and December 6 forecasts, predicting 17 named storms (10 is average), nine hurricanes (six is average), and five intense hurricanes (2.3 is average). This is the highest level of activity they have forecast in their 23 years of making these predictions. They put the odds of a major (Category 3-4-5) hurricane crossing the U.S. coast at 82% (average for last century is 52%). The U.S. East Coast (including Florida) has a 69% chance of a major hurricane strike (31% is average), and the Gulf Coast, 38% (30% is average). In addition, there is an above-average risk of major hurricanes in the Caribbean.

The CSU team identified four years that had similar weather patterns in May compared to this year, and all four of these years had much above levels of hurricane activity: 2004 (six major hurricanes, three of which made landfall in the U.S.), 2001 (no hurricanes made landfall in the U.S., but there were two major hurricanes); 1996 (six major hurricanes, one of which hit the U.S.--Fran); and 1961 (seven major hurricanes, one of which hit the U.S.--Carla).

What the other hurricane forecasting groups are predicting for 2006:
NOAA forecast issued May 22, 2006:

13-16 named storms
8-10 hurricanes
4-6 intense hurricanes

Cuba's National Weather Institute prediction from May 2, 2006:

15 named storms
9 hurricanes

Tropical Storm Risk, Inc. May 5, 2006 forecast:

15 named storms
8 hurricanes

The CSU forecasters cite three main reasons to expect a very busy season:

1) Weaker trade winds than usual have led to anomalous warming of the tropical Atlantic since the early part of April. Sea surface temperatures remain much warmer than average, and are expected to be much warmer than average during the August-October peak of hurricane season.

2) No El Ni�o is expected to be present during August-October 2006. When the tropical Atlantic is warm, and no El Ni�o is present, Atlantic basin hurricane activity is greatly enhanced.

3) We continue to be in the positive phase of the Atlantic Multidecadal Oscillation (AMO), the decades-long cycle of natural hurricane activity.

The next forecast from the CSU group will be issued August 3.

Tomorrow--June 1--marks the beginning of hurricane season. I'll have a look at what we can expect for the month of June.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.