Each year, two major meteorological organizations — the National Oceanic and Atmospheric Administration (NOAA) and the Colorado State University Hurricane Forecast Team — issue forecasts for the coming season.
Both are predicting an above-average season.
CSU issued its forecast last month; NOAA issued its forecast last Thursday.
In its 2013 Atlantic hurricane season outlook, NOAA is predicting a 70 percent chance that this season will produce between 13 and 20 named storms — with winds 39 mph or higher. Of those, seven to 11 are expected to develop into hurricanes — with winds 74 mph or higher — and of those, three to six are forecast to be major storms with winds 111 mph or higher.
CSU is predicting 18 named storms, nine hurricanes and four major storms.
The seasonal normal is 12 named storms, six hurricanes and three major hurricanes.
NOAA is basing its forecast on three salient factors that strongly control hurricane activity in the Atlantic combining.
• The continuation of a west African monsoon responsible for an ongoing area of high activity for the formation of Atlantic hurricanes. This climate pattern, it says, began in 1995.
• Warmer-than-average water temperatures in the tropical Atlantic and Caribbean.
• An El Nino that is not expected to develop. An active El Nino helps to suppress the formation of hurricanes.
NOAA stresses that its annual outlook is not a hurricane landfall prediction.
“With the devastation of Sandy fresh in our minds,” says Kathryn Sullivan, the acting administrator of NOAA, “everyone at NOAA is committed to providing life-saving forecasts in the face of these storms.”
Each year, the accuracy of the hurricane forecasts has improved, particularly about predicted paths. The National Hurricane Center routinely forecasts a five-day path a particular storm will take.
Figuring what intensity a storm will reach has proven much more difficult.
A dozen years ago, accompanying one of NOAA’s hurricane research planes to a visit to Corpus Christi, then director of the National Hurricane Center, Max Mayfield, said the capricious nature of a hurricane kept him up at night.
It’s a reasonable forecast that the same scenario haunts current NHC Director Richard Knabb.
Their greatest fear — a tropical storm developing close to shore in the Gulf of Mexico that strengthens so quickly that suddenly the NHC has a category 5 hurricane right offshore — no time to evacuate, little time even to issue warnings.
All the satellites, all the hurricane hunters, all the proverbial king’s horses and men would be powerless as a major hurricane slams ashore.
Predictions of a storm’s potential intensity has never kept up with the accuracy of path prediction.
This season could see the beginning of a breakthrough.
This year, NOAA plans to bring online a new supercomputer to run an upgraded Hurricane Weather Research and Forecasting computer program that provides “significantly enhanced depiction of the structure of a storm” which will improve intensity forecasts.
In addition, this year hurricane hunter aircraft will transmit radar data in real time, which NOAA says will improve intensity forecast accuracy by 10 to 15 percent.
“As we saw firsthand with Sandy,” Sullivan warns, “it’s important to remember that tropical and hurricane effects are not limited to the coastline. Strong winds, torrential rain, flooding and tornadoes often threaten inland areas far from where a storm first makes landfall.”
Her concern is mirrored by Joe Nimmich, the associate administrator for response and recovery for the Federal Emergency Management Association. “Preparedness today can make a big difference down the line, so update your family emergency plan and make sure your emergency kit is stocked.”
Proper preparations for the season is available at www.ready.gov/hurricanes and www.nhc.noaa.gov/prepare/.