Wednesday, July 14, 2010

Tropical Update-What the heck is going on?

Needless to say, aside from the E PAC the tropics are rather quiet. So, I been analyzing a few different things and trying to figure out what is actually happening and occurring. Or maybe the more appropriate way of saying it is what is missing?

Well first off we already know that we are headed into La Nina territory for the most part. We also know that we have a + AMO and we also know that we have some very warm SSTS that are available..However the one thing we do not have, outside the pacific is any tropical waves that are developing into Tropical Cyclones. Things are quiet and this is a post to look at and explain what I am seeing as the problems at hand.

First off lets look at what is called the shear tendency map current for 03Z on the 14th.

wg8sht

Notice how shear is increasing over parts of the GOM, Southern Carribean and the Atlantic and also towards the coast of Africa? Whenever you have increasing shear you have potential problems with cyclone development. However…that’s not all that is going on.

To explain the next part we are going to look at several graphics. First off alot of these high season hurricane totals of 20 + storms were built on the premise of the Azores high pressure being weaker then it actually is.

Before we look at where this is set up lets look at how the basins in the atlantic are set up.

GE_subs

Notice where the subtropical Atlantic is,Now lets look at the tropical initialization of the 7-14 00z GFS and lets notice where that high pressure is..

00zgfs500mbHGHTPMSLtropical000

Now the first thing you notice is that it is located in the subtropical Atlantic. The second thing you notice is the strength which is 1032. The third thing you notice is the expanse in size. To get a better picture of the expanse in size..on the water vapor image it can be defined by the black color.

wv-l

Notice the expanse in size from west to east, east to west on to the SE coast and far south into the Carribean. This I feel is a major factor in what is keeping things suppressed in the Atlantic at this point in time. Another thing you notice in that image is all the dry air by the orange color, also called SAL.

So what you have is shear increasing, dry air, a stronger Azores high pressure area and a southern located ITCZ. Factor in  on top of that a record 30 year global ACE, a strong negative QBO and the picture becomes clearer as to why despite the MJO being in favorable location for some time (other then the short time in the COD) ..the results so far is only one named storm which was Alex.

Let me be perfectly clear..I am not saying that the season is going to bust etc but the calls of a season out doing 2005, and the extremely high calls of 20 + storms are in trouble!

Until these conditions let up..pretty much expect to see a quieter Atlantic and a more active E PAC.

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