Bermuda High Watch

[Blown Away]

Seems there is a good chance the ingredients for an active 2010 Hurricane season are going to be in place, dissipated El Nino, warm MDR, lower pressure, etc. I would like to know if there is a way to get some subtle hints this spring on how strong/weak the BH will be during the hurricane season? I assume the warmer MDR now is a result of a weaker BH during this winter, thus weaker trade winds to upwell the cooler waters?? It's been a very, very cold winter for SFL standards, coldest I can remember!

[TreasureIslandFLGal]

It appears that the Bermuda High is already setting in place further south this year than last, and currently a bit weaker than normal.

The consequence is that storms that follow the periphery of the High as they come across the Atlantic are more likely to reach the caribbean and lower US than simply make a beeline for the northern east coast or out to sea. They will likely be more "southern trackers".

However, if the Bermuda High is rather weak, there is a chance that a storm that intensifies quickly off Africa will shoot north in between the predicted stronger Azores high and the Bermuda high, so not affect anything but potentially Bermuda.

But if the storm takes time to ramp up, or develops further west, it will not track further north than where it meets that Bermuda High that is already sitting in lower latitudes than normal. Any storm will have to dance along that before it reaches its weaker edges and can then curve north, following the High's periphery. Depending on how strong the high is at the time of the curve and where exactly "the edge" of it is sitting (strength and position fluctuates a bit throughout the season) off the SE US coast, that will make the difference as to where landfalling storms will go.

The season of the low parade of storms that tracked one after the other south of Hispanola and Cuba and into the gulf, (2004 I believe?) comes to mind. That too had a low latitude Bermuda High scenario that allowed that sort of low traviling storm parade to get set up. If such a Bermuda High establishes itself again, and is close to the US coast, then everything goes into the gulf or the Yucatan. If it positions further from the US coast, then storms tend to head into the Carolinas or stay offshore and recurve after threatening them. If the High is in between those two scenarios...then it's look out Florida!

The best news is that the high, at least now, is expected to not be very strong, which could allow for more of those recurves without affecting land. But the closer to peak and 3/4 into hurricane season we get, the more likely that the Bermuda High would be in its stronger phase vs. its beginning season weaker status that it is showing now.

I think that this helps explain the high threat numbers for this season regarding landfalls.

[gatorcane]

What the Bermuda High is doing now does gives no indication of what it is going to do during the height of the hurricane season. Furthermore it's the ephemeral positioning that is most important as all it takes is a tropical system to form at the right position at the right time with the High in the right position for it to make landfall -- even if the Bermuda High is not semi-permanent.

[KWT]

Yeah and the best example you can look at has to be 2004, the trough remained solid down the east coast till Mid August (indeed it gave charley more of a classic October track) then just as things hotted up it all shifted for about a month and in that time we obviously had Frances, Ivan and Jeanne all make landfall in Flordia.

[cycloneye]

I found on the net this very interesting game about the highs and lows in terms of the positions,then you track a hurricane to see where it would go depending on what positions you put the highs and lows.Follow the instructions and you will see how neat it is.

http://www.nhc.noaa.gov/HAW2/english/kids/movncane.swf

[Annie Oakley]

How fun Cycloneye! Thanks for finding that.

[Stephanie]

That was fun! Thanks Luis.

[gatorcane]

Thanks cycloneye, the link is pretty cool. I tried several different scenarios with the positioning of the Highs and the Lows. The only thing I have to say is that it does not take into account the fact that the Highs and Lows will likely change positions and strength throughout the duration of the path which would influence the path of the tropical system. Instead it assumes the Highs and Lows are static. Still, it does demonstrate how Highs and Lows influence the path of tropical systems in the Atlantic.

[Blown Away]

I think this helps those including myself understand how JB called for lower pressures in the Atlantic and farther west tracking hurricanes. Is there any early season indicators to let us know if that BH will be setting up farther west?

“We’ll have to see how much ridging develops across the mid-latitude Atlantic,” Klotzbach says. “If the Bermuda High moves westward, you will see storms track more west.”

Atlantic Ocean Tripole

Another feature that may influence tropical cyclone formation this season is the emergence of the Atlantic Ocean Tripole – a tiered temperature pattern characterized by a warm North Atlantic, cool Central Atlantic and warm tropical North Atlantic.

The staggered structure of the ocean temperatures – warm to cool to warm – favors more tropical cyclone development in the Atlantic basin breeding grounds, increasing the likelihood of more storms tracking into the southwest Atlantic, Caribbean and Gulf of Mexico, according to Accuweather meteorologist Joe Bastardi.

“This temperature pattern, the Atlantic Ocean Tripole, results in lower pressures in the tropical development region and higher pressures in the Central Atlantic – from Bermuda to the Azores – which tends to drive storms farther west,” Bastardi explains. “We’re also seeing the end of El Niño and the onset of La Niña conditions, something I’ve been predicting since February. Unfortunately, the pattern resembles what we saw going into the 1998 and 2005 seasons.”

I pulled this out of Kirk Myers, Columnist with Examiner.com, Article.

Here is the link:

http://www.examiner.com/x-32936-Seminol ... Nino-fades