Greenland/Canada high and hurricane season

[MiamiensisWx]

I have noticed that we have had an interesting pattern in late April and through this month. We are seeing more of a lack of western Atlantic ridging than we did earlier this year (such as in March), while the eastern Atlantic is seeing more of an establishment of the Azores High, unlike earlier this year. Ridging is also repeatedly attempting to settle over the Rockies and into the Great Plains area, resulting in weaker western Atlantic ridging, more dominant troughiness, and - most interestingly - more later cold fronts swinging through the U.S. and into the southeastern, central, south-central, and northeastern parts of the country. At the same time, we are also seeing a negative NAO setup now, with a dominant trouginess (eastern U.S. coast and western Atlantic) and Greenland/Canada high (or Greenland Block) scenario, typical in many negative NAO patterns which result in more eastern U.S. troughiness. Current patterns suggest this may persist and continue. I have noticed this weaker ridging over Florida. Earlier this year, we had western Atlantic strong upper-level ridging repeatedly attempting to set up. At that time, there was still a negative NAO, but the pattern was different than now overall. Now, however, we are seeing weaker and less persistent ridging, especially at the upper and lower levels. Also, current ridging over Florida has become less Atlantic in origin than earlier, resulting in more favorable conditions for more moisture and western thunderstorms over the Everglades and southeast Florida due to seabreeze convergence as a result of weaker ridging, rather than wet conditions resulting from easterly flow around a strong Atlantic middle to upper-level high. La Nina is gone, but there are other interesting patterns at work. I am interested to see if all these current factors and general pattern persists into the season. If so, such a pattern may result in the following...

-Active Cape Verde season due to favorable upper-level support from a more dominant Azores High in the eastern and central Atlantic
-A larger number of fish storms, and the storms that do approach from the east that threaten the U.S. eastern coast may target North Carolina more than southern Florida due to low-level and upper-level steering patterns and troughiness/weak ridging patterns; this would mean that Florida's greatest threat for a hit(s) might come later in the season from the southwest from the western Caribbean (e.g., another Irene, Wilma, or close brush like Michelle from 2001); we may see a Floyd or Gloria-type or Isabel-type threat to the eastern U.S. coast, especially north of Florida and possibly to New England, if the pattern(s) hold
-A greater threat to the far western Gulf (Texas and Mexico) and western Caribbean due to ridging extending south-southeast over the western and west-central Gulf of Mexico, forcing storms westward; in these type of patterns, an active Bay of Campeche season might be in store if current patterns hold, resulting in threats to Mexico and more Texas threats

I know that it is WAY too early to say what the setup will be later on and if this will last; I am just outlining a possible setup. Does anyone agree? What are your thoughts? Any thoughts?

[terstorm1012]

I noticed that Newfoundland Wheel just sittin' up there and spinnin' away its merry self too man...

Though I think it's too early to speculate. If the pattern persists into late June, then I will raise a bit of concern.

[MiamiensisWx]

Besides the negative NAO, does anyone know why or have any thoughts why we are in this pattern I mentioned above?

[MiamiensisWx]

Any thoughts from any professional mets here?

[gatorcane]

unlike earlier this year. Ridging is also repeatedly attempting to settle over the Rockies and into the Great Plains area, resulting in weaker western Atlantic ridging, more dominant troughiness, and - most interestingly - more later cold fronts swinging through the U.S. and into the southeastern, central, south-central, and northeastern parts of the country

in 2004 strong cold fronts came down into August - allowing Charley. Then in September the pattern completely reversed with deep ridging in the western Atlantic allowing Frances and Jeanne. These fluctuations are currently entirely impossible to predict at this point.

[MiamiensisWx]

That's not what I mean, boca_chris. I meant that we are seeing more and cooler fronts coming through the U.S. in general later (like in May rather than April).

[gatorcane]

In 2004, I remember fronts approaching Florida into June - increasing the instability across the peninsula for summer-time pops.

Yet May and September were dominated by a monster Bermuda High. There
will be breaks in the pattern - it is all TIMING.

[MiamiensisWx]

I know; it is still too early to tell. However, the current pattern is different in several respects than anything we had throughout 2004.

[CHRISTY]

Guys its still just to early to know.I will say on may 22 we will have a much better idea of what might be shaping up!i think there is a 50/50 chance we will switch into a positive NAO by mid july or august.again we just dont know what's gonna happen.but think about it florida has multiple hurricane strikes in 2004 and 2005 i really dont think we can escape 06 without a hit!I feel florida is under this similar pattern like back in the 1950's and 1940's were florida got hit very often.

[terstorm1012]

CVW, this site may help you with your question : http://theweatherprediction.com/blocking/

[MiamiensisWx]

Thanks!

[CHRISTY]

THIS A GRAPHIC OF HURRICANES THAT STRUCK SOUTHEAST FLORIDA DURING NEUTRAL YEARS...



THIS IS A GRAPHIC OF HURRICANES THAT HIT SOUTHWEST FLORIDA DURING NEUTRAL YEARS...

[MiamiensisWx]

Any more thoughts?

[terstorm1012]

What I'm thinking, CVW, is the block will persist through the next week to week and a half. Beyond that I'm not sure, but I haven't gone and plumbed through the available data yet.

The above is not a forecast. It just seems to be the trend as of late.

[MiamiensisWx]

I think it may persist for at least a while more, too.

[MiamiensisWx]

The negative NAO blocking Canada/Greenland ridging is VERY evident in the setup and model guidance as well.

[Scorpion]

Its May. Last year had much more troughs. Things will change by August, just like they changed from March to this month.

[MiamiensisWx]

Nope. Many hurricane outlooks are against this.

Proof? Links, please.

[MiamiensisWx]

Its May. Last year had much more troughs. Things will change by August, just like they changed from March to this month.

True, it could, and I know it is WAY too early to tell; I am merely discussing the current pattern setup and what might play out if it persists.

[Scorpion]

You were harping on a strong Bermuda High in March. Point is, things will continue to change. The troughiness is not abnormal at all. There is not supposed to be an established Bermuda High this time of the year.