A bit disconcerting.

[OuterBanker]

The following is just my own personal observations of local trends. I am not a meteorologist, just a weather nerd.

This summer is like no other I have experienced since I moved here in 1974. It has been the hottest summer I can ever remember, yet you have been able to swim the entire summer.

Let me explain, usually hot summers mean land breezes which take the warmer gulf stream waters out to sea and allow the much cooler Labrador current to up well to the surface. This means that while the air temps and sand are very hot the sea temp is too cool to swim in. One hot summer a few years ago you could not swim in the ocean the entire summer. Here on the northern Outer Banks (north of Oregon inlet) the waters get much cooler due to upwelling. Where an east wind will bring in 80 sst's and temps, a west wind will bring in 90 air temps and water temps in the high 50's to low 60's. Fry your feet and freeze your a** in other words. This has been a constant since I've lived here. Until this year.

So far this year I have not seen the sst drop below 70 in the hottest summer to date. Yes, upwelling has occurred, but the sst difference has only been a few degrees as against a more typical 10 to 15 degrees. The most obvious and logical answer is that the Labrador current is much warmer than normal, that the warmer gulf stream waters are deeper near the shore, or a combination of both. Which leads me to some questions and personal conclusions. It is my understanding through observations over the years that once hurricanes move pole ward after about 35N (think Cape Hatteras) that conditions change drastically. The aforementioned upwelling pretty much means that the hurricane loses the heat it needs and most transition to a more hybrid system. They become less symmetric and most importantly weaker which is why it is quite rare for a major hurricane to make landfall north of Cape Hatteras. Most exceptions (i.e. Hazel, Donna) were due to forward speed. This leads me to the following conclusions. I welcome the mets and experts to chime in and point out my misconceptions and errors.

1 - That the sea surface temperatures north of Cape Hatteras are warmer than normal. In addition it appears the warmer waters are deeper than normal which means upwelling would occur later than normal.

2 - That if areas north of Cape Hatteras were threatened (which would include the major metropolitan areas on the east coast) it could mean a stronger and more powerful hurricane.

I hope I'm wrong.

[Riptide]

Good call and discussion, this is something I have noticed as well living close to the ocean. It's not something that you can simply ignore or brush aside as a minor factor. I'm also wondering about next winter and the kind of baroclinically-enhanced systems impacting coastal areas. The warmer water often causes more extremes in all sitiuations in the atmosphere. So far there has been nothing to work with in the tropical Atlantic so mabye the East Coast will get a free ride this year. JB and many others could be right with the idea of a home brew year with systems (tropical cyclones) forming within 500 miles of the conus.

Since Irene, there has been less interest in mid-laditude hurricanes but it's just one minor event in a long history of high-impact events going to back to the colonial era. Higher sea surface temperatures will prevent less Irene-like(Hybrid) events from occuring, even though the cause of Irene's lack of organization was due to other factors such as wind shear and slow forward speed.

Another point of concern is that 4 out of 4 tropical systems this year have formed north of 20N, particularly Hurricane Chris which formed north of Bermuda.

[hurricanetrack]

Very intelligent obs there outerbanker. I am impressed. The only thing I can add is that I have read some thoughts from other pro mets about how this period of time resembles the 50s in a lot of ways and we all know the history of NC hurricanes in the 50s. We shall see... Excellent post though!

[Frank2]

High SST's are important, but mean nothing if the upper-air environment does not support a tropical system - once El Nino begins shear will become a big issue...

[CrazyC83]

Mid-latitude hurricanes are also completely different than tropical hurricanes. They tend to have a larger more asymmetric windfield and less defined cloud shield, yet can still be very strong and dangerous.