Just like last year, the six-month hurricane season is off to a lightning-quick start.
Fortunately, a fast start does not necessarily mean a busy season.
Arthur, the first named storm of the season, was downgraded to a tropical depression Sunday, the season's first day, after making landfall at the Belize-Mexico border Saturday. It continued to produce heavy rains over parts of Central America and southeastern Mexico on Sunday afternoon.
Rain, heavy at times, could continue in the region for two or three days, but the system is forecast to stay over land, said Richard Knabb, a senior hurricane specialist with the National Hurricane Center in Miami. The center's computerized hurricane models were in near-unanimous agreement.
It's not unprecedented for tropical systems to form outside the season, which runs through Nov. 30, Knabb said. Between 1851 and 2006, 33 tropical storms formed during off-season months — December to May.
Last year began quickly, too.
First, benign Subtropical Storm Andrea bounced along the Atlantic coast in early May. About three weeks later, Tropical Storm Barry dropped several inches of rain when it made landfall in the Tampa Bay area June 2.
Historically, 79 tropical storms have formed during the month of June. Twenty-eight of those became hurricanes. Sixty-one tropical storms have formed in November, which logs the second-lowest number of storms during seasonal months. Thirty-nine of those have turned into hurricanes.
Compare that with peak season months like August and September. Over the same 155-year period, 344 tropical storms formed during August (with 217 becoming hurricanes) and 459 during September (with 319 becoming hurricanes).
The reason, for the most part, is water temperature. It's often plenty hot in June — the forecast for the Tampa Bay area today calls for temperatures in the low 90s — but it takes a month or two for gulf and Atlantic temperatures to rise to levels favorable to storm formation.
But there's no correlation between how early in the season the first storm strikes and the number, size or strength of storms during a season, Knabb said.
The National Oceanic and Atmospheric Administration this year predicted 12 to 16 named storms in the Atlantic region, including six to nine hurricanes and two to five major hurricanes (Category 3 or higher).