Although there has already been activity in the form of “Subtropical Storm Ana,” the Atlantic hurricane season officially begins today. There is presently no activity in the Atlantic, and none forecast for foreseeable future (which is only a few days). There are some weak systems in other parts of the world including Choi-Wan, a tropical storm decaying to a depression as it brushes the northern Philippines. So how does the year look? We’ll know in December 😛 but for what it’s worth here’s the forecast ..
So the question most people have at this point is what kind of season is coming, and that usually devolves to the number guessing game. It’s likely to be an “normal to above normal” season in terms of overall activity. Here is a link to the official NOAA forecast. In short, hurricane activity in the Atlantic is largely driven by two factors. The first big driver is the state of the El Nino/Southern Oscillation (ENSO) cycle, which drive the big currents in the atmosphere that both control their formation and intensity (through wind shear) and direction of movement. The ENSO state transitioned from La Nina to “Neutral” this spring, and is forecast to stay neutral through the end of the hurricane season, with the possibility of returning to La Nina conditions late in the year. Here is the forecast from the main NOAA model, the Climate Forecast System (CFS):
The second big driver is the heat content in the ocean, which provides the energy for storms. The Atlantic remains above – here is the latest anomaly map (the deviation from long term averages).
You can see that while there are a few cool spots, much of the Atlantic, Caribbean, and Gulf of Mexico remains above normal, so there will likely be plenty of energy for storms to draw from (don’t worry too much about the complex swirls off the US Northeast; that’s just the Gulf Stream, and it meanders so some areas will be hotter or cooler on any given day).
So, what does that all mean? As it turns out, the post I did back in March is still mostly on track (click to read). For the Georgia and SC Low Country coast, the probability of a severe landfall is below normal early and middle part of the season (back door storms and annoying, evacuation-inducing bypassers are always possible) due to the ENSO Neutral conditions. Later in the year the risk is higher – if La Nina returns, risks are above normal for October/November (about a 50/50 chance of that). The Caribbean may be busy early – we’ll have to watch.
But for now things are quiet, so enjoy the late spring and start of summer. Once again as a reminder, this is the time of year to revisit your hurricane plans, especially insurance. There is a “lock out” period for changes prior to a storm and if you wait until one is headed your way, it’s too late. Check out Ready.gov for checklists and advice.