I have never seen the sea surface temperature anomaly map look like the one below. It is the NHC’s Reynolds method anomaly map which is updated once per week. This map gives an excellent representation of what is going on with SSTs across the Atlantic Basin and looking at today’s edition, it is alarming. Such an enormous area, from Africa all the way to the western Caribbean, is at or above 1 degree Celsius above normal. That alone is enough to warrant serious concern for the upcoming hurricane season. However, the fact that a growing area of 2 degrees Celsius is now manifesting itself raises the stakes even higher. While it is true that sea surface temps alone do not cause intense hurricanes, seeing them this warm makes me wonder what will happen once the upper level winds relax and we do in fact get a hurricane to develop? Even the Gulf of Mexico, which was running well below normal until recently, is now mostly cleaned out of those cold anomalies. This has huge implications for the efforts to thwart the oil leak crisis in the Gulf- the last thing they need is a hurricane to come plowing through.
So what is causing this incredible warm up in the Atlantic? I have discussed this earlier in the year but will address it again. Basically, lower than normal pressures in the sub-tropical Atlantic are causing the trade winds to be weaker and are thus not blowing across the deep tropics as strong, resulting in less evaporation and cooling. That is the simple explanation. Now it seems like it is feeding back on itself as the warm ocean leads to more heat and moisture and thus lower air pressure. Climate models suggest that this pattern will remain in place for the duration of the season ahead- but none of them have predicted this much warming that I can recall. I hate to sound like Mr. Doom and Gloom here but I am serious, I have never seen anomalies this warm across such a large area of the Atlantic- not even during the 2005 season.
With only a few weeks left until the season begins, the Herculean effort in the Gulf to stop the leaking oil becomes that much more important. I do not want to think about what could happen if a hurricane, let alone a major hurricane, were threaten those efforts. I do not know much about how oil and the ocean interact with each other except only that oil is lighter than water. I wonder if a hurricane would act as the ultimate dispersement agent and break up the slick enough to render it far less problematic? The heavy rain, aggitated sea state and strong wind could do a lot to break down the slick and spread it out over a much larger area- resulting in less concentration in a single region. I suppose though that it is a matter of picking your poison. Unless the oil just goes away, there is no good outcome. However, with the clock ticking towards the start of the hurricane season, it is something that needs to be considered and I would assume that the powers that be who are involved with the efforts are well aware of this added urgency.
I will post another update here on Wednesday with a look at long range computer models as well as some thoughts about our June 1 broadcast as we open the 2010 hurricane season. …..I will post his update later this morning.