Excellent analysis on steering curents by Jeff Masters 7/27

[wxmann_91]

That's the 384 hr GFS. Almost never verifies. Take it w/ a grain of salt

[johngaltfla]

Out of 6 months of hurricane season we truely have about 2 months of active tropical weather. Aug 1st thru Oct 15th. In the other months 1 or 2 storms here and there. This statement excludes the 2005 season. My 2 cents.

Yes, Boca, I do not disagree. But if we get just one Cat 3 the last week of November, my area is pancaked.

So I keep my vigilance up through early December....

This pattern shift is disturbing and watching the waters begin to crank up makes me wonder just what we will be enduring by Labor Day.

That is when I fear we will be dealing with another bevy of news crews standing on our local beaches again.

[Steve]

Main potential big-ticket item on that run was the energy coming into the west-central Panhandle of Florida.

As for the 384 GFS bringing back a trough in the east, I was wondering when it was going to return to form. I was thinking maybe the bias was corrected, but apparently it has not been (assuming there's no trough out there at the time or only something transient).

Steve

[Extremeweatherguy]

18z GFS no longer shows the east coast trough returning on day 16. Instead it now shows the bermuda high parked in the western Atlantic during that time...

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/fp1_384.shtml

[windstorm99]

Thanks extremeweatherguy...

I usually dont buy into long range forcast as the more you go out in time with a particular model the skill level begins to drop significantly.

[elvinp]

Here is the Discovery Channel article supporting the shift in the current climate pattern. The link was too long.

July 20, 2007 — The U.N.'s weather agency on Friday said a disruptive La Nina climate pattern was taking shape in the Pacific, raising the prospect of an active Atlantic hurricane season and strong monsoons in Asia. The World Meteorological Organization (WMO) said in a statement that the development of La Nina in the second half of 2007 was now "more likely than not" after an initial hesitation in the past two months. The combination of tropical wind patterns over the Pacific Ocean and cooler than normal sea temperatures off the Pacific seaboard of Latin America generally has an impact "of planetary scale," WMO scientist Rupa Kumar Kolli said "La Nina conditions are frequently associated with stronger monsoon rainfall and flooding in Asia and... higher frequency of hurricanes in the Atlantic," he told journalists. "Now things seem to be on track for the development of La Nina, but it is likely to be a weak La Nina event rather than a strong one."
However, the WMO highlighted other unusual climatic conditions in the Atlantic and Indian Ocean which could reinforce the disruption to local weather in the coming months. They included warmer than usual sea surface temperatures in the North Atlantic, an unusually warm sea current off the Atlantic coast of southern Africa, and similar warm conditions in the western Indian Ocean.

[meteorologyman]

I personally don't look out that far either, I just mention that the GFS predicted a low of 1008mb, which was the lowest it ever predicted this year, but since it was 16 days out I knew that, that was never going to happen

[Blown Away]

Doesn't the EC Trough become more persistent w/ La Nina conditions?

[Hybridstorm_November2001]

Not exactly my friend. Usually in a La Nina year you have more of a Mid-West/Great Lakes Trough, which steers storms up the East Coast as opposed to a Coastal Trough that deflects them out to sea.

[Hybridstorm_November2001]

Now if we get a strong enough, and fast enough developing La Nina, too shift the steering patterns before the peak of Hurricane Season passes is a whole other matter. We shall see we shall see, I guess.

[Frank2]

Still, a shift in the Bermuda high is not the only ingredient needed for an active season - this does not consider shear, whether caused by ULL's or other sources, lower SST's in the Eastern Atantic, troughs in the Eastern Atlantic (if the high is building in the Western Atlantic, it's bound to mean it's weakening in the Eastern Atlantic), SAL, etc., so, saying that the high is the only thing needed for an active season, is similar to saying that all a cake needs is sugar...

And, hard to believe, but, September is only 5 weeks away, so, time is passing...

[Sanibel]

Here in New York a retrograding Low has pushed heavy rain in from the SE off the Atlantic. Cool in the 60's with steady rain in late July. Fairly rare. This is probably the start of the pattern shift spoken of by Masters. The unseasonably deep trough will probably buckle and collapse allowing a more zonal flow with a receding jet into Canada. Then the Bermuda High will fill in and allow a more normal ITCZ wave train (possibly).

[Stormcenter]

Still, a shift in the Bermuda high is not the only ingredient needed for an active season - this does not consider shear, whether caused by ULL's or other sources, lower SST's in the Eastern Atantic, troughs in the Eastern Atlantic (if the high is building in the Western Atlantic, it's bound to mean it's weakening in the Eastern Atlantic), SAL, etc., so, saying that the high is the only thing needed for an active season, is similar to saying that all a cake needs is sugar...

And, hard to believe, but, September is only 5 weeks away, so, time is passing...

It can't pass quick enough. I'm looking forward to football season hopefully NO major
hurricanes.

[Hybridstorm_November2001]

Speaking of Jeff Masters, his must recent summation of the Pattern for the roughly next two weeks seem far more reasonable than his earlier proclamations:

"The long range GFS model shows that the steering pattern for the next two weeks will be much different than what we saw in 2006 and so far in 2007. We will no longer have a dominant trough of low pressure over the Eastern U.S. that will act recurve storms out to sea. Instead, an alternating series of weak ridges and weak troughs rippling along the jet stream is expected. No particular region of the Atlantic will be at higher risk of being hit with such a pattern."


Source:

http://www.wunderground.com/blog/JeffMa ... amp=200707


I also see no scientific reason why this would not be the case, with the current projected setup.

[Sanibel]

The first thing I think about after reading "which puts no particular place along the Atlantic coast at risk" is the GOM in October, since it hasn't had a good threat since that storm that hit Cuba 5 years ago or so. What was that Michelle?

[Andrew92]

The first thing I think about after reading "which puts no particular place along the Atlantic coast at risk" is the GOM in October, since it hasn't had a good threat since that storm that hit Cuba 5 years ago or so. What was that Michelle?

Yeah it was Michelle. But there was Wilma just two years ago as well!

-Andrew92

[cheezyWXguy]

The first thing I think about after reading "which puts no particular place along the Atlantic coast at risk" is the GOM in October, since it hasn't had a good threat since that storm that hit Cuba 5 years ago or so. What was that Michelle?

Yeah it was Michelle. But there was Wilma just two years ago as well!

-Andrew92

And Katrina, and Rita...and Ivan...lol. But there have been a lot of GOM threats in recent years, especially 2004 and 2005.

[Andrew92]

The first thing I think about after reading "which puts no particular place along the Atlantic coast at risk" is the GOM in October, since it hasn't had a good threat since that storm that hit Cuba 5 years ago or so. What was that Michelle?

Yeah it was Michelle. But there was Wilma just two years ago as well!

-Andrew92

And Katrina, and Rita...and Ivan...lol. But there have been a lot of GOM threats in recent years, especially 2004 and 2005.

He said just October though.

[cheezyWXguy]

He said just October though.

oops my bad

[boca]

Any ideas of when this trough in the east pattern will finally change?