Seasonal forecasts for the Atlantic, Caribbean and Dominican Republic hurricane season 2012

The 2012 hurricane season for the Atlantic Ocean, Gulf of Mexico and Caribbean

The 2012 Atlantic hurricane season should be relatively tame with a total of 12 named storms and seven hurricanes

Forecasts of hurricane activity are issued before each hurricane season by noted hurricane experts Philip J. Klotzbach, William M. Gray, and their associates at Colorado State University; and separately by NOAA forecasters. CSU’s December 2011 discussion was notable in that the forecasting team announced it would no longer attempt quantitative forecasting nearly six months out, noting …forecasts of the last 20 years have not shown real-time forecast skill. They will, however, release a quantitative forecast for 2012 in April.

Three hurricanes are expected to be « major » with sustained winds of at least 111 miles per hour, with Category 3 or greater status on the Saffir-Simpson intensity scale, Weather Services International (WSI) said in its early pre-season forecast.

The Atlantic hurricane season officially starts on June 1 and ends November 30 and 2011 saw a total of 19 named or tropical storms of which seven became hurricanes, including three major hurricanes.

Irene was the lone hurricane to hit the United States in 2011, but it was first one to do so since Hurricane Ike struck southeast Texas in 2008. Irene was also the most significant tropical cyclone to strike the Northeast since Hurricane Bob in 1991, according to U.S. government forecasters.

In its forecast on Tuesday, WSI chief meteorologist Todd Crawford said the North Atlantic Ocean had cooled to levels unobserved in a decade, fueling hopes for a relatively mild 2012 storm season.

Crawford was also quoted as saying most forecast models suggest an end to the cyclical La Nina weather phenomenon, which fosters hurricane formation.

Crawford stopped short of making any specific predictions about possible hurricane landfalls in 2012, saying there were no strong signals about any threats to the U.S. coastline so far. But he said the energy-rich U.S. Gulf of Mexico and Florida may see some increase in storms. For 2012, our landfall model depicts close-to-normal probabilities of landfall along the U.S. coastline, slightly elevated chances in the Gulf and Florida and slightly reduced chances along the East Coast, he said.

The team predicted:

• A 45 percent chance of an above-average THC and no El Niño development, raising hurricane activity to about 140 percent of the average season, with 12-15 named storms, seven to nine hurricanes, and three to four major hurricanes.
• A 30 percent chance of an above-average THC and a “significant” El Niño, reducing hurricane activity to about 75 percent of the average hurricane season — eight to 11, three to five, and one to two.
• A 15 percent chance of an “unusually strong” THC and no El Niño, bringing activity nearly double the average — 14 to 17, nine to 11, and four to five.
• A 10 percent chance of a weak THC and a a significant El Niño, bringing activity at 40 percent of the average season, or five to seven named storms, two to three hurricanes, and zero to one major hurricane.

Pre-season forecasts

On December 7, 2011, Tropical Storm Risk (TSR), a public consortium that compromises experts on insurance, risk management and seasonal climate forecasting at University College London, issued an extended-range forecast predicting an above-average hurricane season. In its report, TSR noted that tropical cyclone activity could be about 49% above the 1950-2010 average, with 14.1 (±4.2) tropical storms, 6.7 (±3.0) hurricanes, and 3.3 (±1.6) major hurricanes anticipated, and a cumulative ACE index of 117 (±58). On December 21, 2011, Weather Services International (WSI) issued an extended-range forecast predicting a near average hurricane season. In its forecast, WSI noted that a cooler North Atlantic Oscillation not seen in a decade, combined with weakening La Niña, would result in a near average season with 12 named storms, 7 hurricanes, and 3 major hurricanes. They also predicted a near average probability of a hurricane landfall on the USA coastline, with a slightly elevated chance on the Gulf Coast and a slightly reduced chance along the East Coast.

2012 storm names

The following names will be used for named storms that form in the North Atlantic in 2011 :

Alberto, Beryl, Chris, Debby, Ernesto, Florence, Gordon, Helene, Isaac, Joyce, Kirk, Leslie, Michael, Nadine, Oscar, Patty, Rafael, Sandy, Tony, Valerie, William

Predictions

Named Storms : 12

Named Hurricanes : 7

Named Storm Days : 85

Hurricane Days : 40

Intense Hurricanes : 3

Net Tropical Cyclone Activity : 165

Landfall Probabilities for 2012

For the 2012 season, Klotzbach and Gray expect an active season overall, but with normal intensity for the Atlantic and a normal impact rating on the U.S. coast. In terms of numbers, they forecast 11 named storms, six hurricanes and two intense hurricanes and a more active recent average of 15 named storms, eight hurricanes and four intense hurricanes.

An average Atlantic hurricane season has 12 named storms, 6 hurricanes, and 2 major hurricanes.

Probabilities of the affected territories

These are finally probabilities that certain territories will be affected by an intense hurricane in 2012:

• A 58% chance that at least one major hurricane will make landfall on the U.S. coastline in 2012. The long-term average probability is 52%.
• For the U.S. East Coast, including the Florida Peninsula, the probability of a major hurricane making landfall is 49% (the long-term average is 31%).
• For the Gulf Coast from the Florida Panhandle west to Brownsville, the probability is 48% (the long-term average is 30%).
• The team predicts the probability of a major hurricane making landfall in the Caribbean as 62% (average for the last century is 42%).

Weather

Dominican Republic
& Puerto Rico