Here Comes Ana
Even though hurricane season doesn’t begin until June 1, the disturbance above could become the first named tropical system of 2015 – Ana. Hurricane hunters will investigate this cloud mass Wednesday and determine if there is a closed circulation and whether the winds around the system meet the tropical storm threshold of 39 mph.
Computer projections indicate that the system will likely become Tropical Storm Ana Wednesday and meander around the South and North Carolina coasts for several days before being drifting out toward the Atlantic:
The above is the familiar “spaghetti plot” showing the forecasts from various computer models run whenever there is a tropical system. The various colored lines correspond to models that focus on various aspects of the atmosphere or climatology. The simplest model, called the XTRP is a simple extrapolation projecting the future location of the storm based on it’s current heading. Other models, like the AVNI are based on a dynamic computer model.
As far as intensity, the models are split as to whether Ana will reach tropical storm strength. But those that do, believe Ana will spend several days as a tropical storm but not reach hurricane intensity:
So, how unusual is it for there to be a pre-season storm and what does it mean for the remainder of the year? Before I researched this, I had the opinion that it was a rare event. But after actually digging into the numbers I was surprised at what I found.
In the decade of the 90s, there were three pre-season storms, in 1990, 1992 and 1993. In 1990, after Tropical Depression #1, sixteen named storms formed with 8 hurricanes, but only Tropical Storm Marco struck the U.S. From 2000-2009, pre-season storms occurred 4 times. However, even in the record-setting 2005 year, this was not the case. In each year that there were storms before June 1, the seasons were mostly active:
Year Pre-June 1 Storm Season Total Hurricanes
2003 Ana (4/21-24) 21 7
2007 Andrea (May 6-14) 17 7
2008 Arthur (May 31- June 2) 17 9
2009 TD 1 (May 26-30) 11 3
The most recent occurrence of an early season storm was 2012, when two preseason storms, Alberto and Beryl formed in May. That lead to a very active year with 19 storms and two memorable hurricanes – Isaac and Sandy.
The predicted El Nino is projected to lower the total number of storms that form in 2015, so it will be interesting to see what unfolds. Too often, the weather community and the public tend to focus on numbers, but everyone living along a coastal area should prepare for hurricane season. Remember, it only takes one destructive storm in a heavily-populated area to create a long-lasting memory.