Wind shear decline expected across the atlantic basin....

[windstorm99]

Good afternoon...

I just read Jeff Masters morning update and he makes note that in the coming days things could quite favorable as far as upper level winds are concerned across the atlantic basin which could make things interesting in july.

Here is part of his blog today.

Wind shear decline expected
The jet stream usually divides itself into two branches this time of year--a strong jet whose average position is near the U.S.-Canadian border (the polar jet), and a weaker branch whose average position is over the Gulf of Mexico (the subtropical jet). Both of these branches of the jet stream bring high upper level winds (and thus high wind shear) over the Atlantic Ocean. All of the computer models are forecasting that the subtropical jet will weaken substantially over the next ten days, bringing much lower than average wind shear to the tropical Atlantic. It is normal to see the subtropical jet weaken in the summer, but it usually happens a month later than this--in August. The expected early weakening of the subtropical jet should give us an above-average risk of a July tropical storm. I'll have a full analysis of the possibilities on Monday, when I post my bi-monthly 2-week outlook.

Entire blog here

[Eyewall]

cool
can't wait

[Tampa Bay Hurricane]

Uhhh ohh....
Wind shear decline...could that lead to storms???

[miamicanes177]

can someone post a link to the forecast wind shear?

[Frank2]

I'd take that with a grain of salt - first the comment "Wind shear decline expected..." that says it all...

and, if it were to happen instead of August, all the better, since that could mean that an increase in shear towards the height of the season...

aside from that, there are so many other variables (SAL, etc.,) that there is no way to know for sure...

Frank

[TheRingo]

I'd take that with a grain of salt - first the comment "Wind shear decline expected..." that says it all...

and, if it were to happen instead of August, all the better, since that could mean that an increase in shear towards the height of the season...

aside from that, there are so many other variables (SAL, etc.,) that there is no way to know for sure...

Frank

why? would the jet come back down in august? what makes you say that?

[Frank2]

Well, not sure, but, if the shear declines for a period then it's possible that it would increase once again, since weather patterns do oscillate that way...

Timing is everything when it comes to something like that, that's for sure...

There have been many seasons that had optimum conditions for development, but, happened at the "wrong" time of the season - we'll see...

[cpdaman]

i would assume that it would shift back as well....in october

[wxmann_91]

Well, given that we're heading toward the heart of the season, this shouldn't be a surprise.

In any case, this early in the year, instability is more important than how much shear there is...not saying either can be ignored of course.

[Andrew92]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Yikes, the amount of shear is decreasing IN JULY? Yes, it is quite possible that the shear could pick back up near the climatological peak of the season. But is it likely? We'll have to see, but I'm going to say no.

Why? Mainly because this year is high unlikely to be an El Nino year. I'm not discounting the fact that La Nina may go kaput this year, but recently neutral years have been just as active, if not more active, than La Ninas (check out 1995, 2003, and 2005 for great examples of this). Now if there was an El Nino forming, then I might say that shear could come in in August to quiet the hurricane season down.

Regardless of SSTs, La Nina/neutral, etc., I believe the setup is there for an active hurricane season, so be prepared everyone!

-Andrew92

[benny]

can someone post a link to the forecast wind shear?

http://www.cpc.ncep.noaa.gov/products/p ... hear_2.gif

Any color other than white in the bottom panels is shear less than 20 kt... which is an approximate upper threshold for most development

[TheRingo]

Well, not sure, but, if the shear declines for a period then it's possible that it would increase once again, since weather patterns do oscillate that way...

Timing is everything when it comes to something like that, that's for sure...

There have been many seasons that had optimum conditions for development, but, happened at the "wrong" time of the season - we'll see...

I understand weather patterns oscillates. But does wind shear oscillate in 30 day cycles? I would think the jet does a yearly oscillation. The question is when will the jet peak in it's northern migration?

Thanks

[caneman]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Yikes, the amount of shear is decreasing IN JULY? Yes, it is quite possible that the shear could pick back up near the climatological peak of the season. But is it likely? We'll have to see, but I'm going to say no.

Why? Mainly because this year is high unlikely to be an El Nino year. I'm not discounting the fact that La Nina may go kaput this year, but recently neutral years have been just as active, if not more active, than La Ninas (check out 1995, 2003, and 2005 for great examples of this). Now if there was an El Nino forming, then I might say that shear could come in in August to quiet the hurricane season down.

Regardless of SSTs, La Nina/neutral, etc., I believe the setup is there for an active hurricane season, so be prepared everyone!

-Andrew92

Well stated!

[Cyclenall]

July is coming together. Most of the factors are coming together for a active July and the wet MJO phase is going to come right on time too. Moisture is pretty decent at this time too.

I'd take that with a grain of salt - first the comment "Wind shear decline expected..." that says it all...

Like with everything else in weather? There is nothing different here from everything else that involves forecasting...

and, if it were to happen instead of August, all the better, since that could mean that an increase in shear towards the height of the season...

Can you explain the logic of that? The sub-jet doesn't behave in a oscillating manner like other weather does except in long periods and seasons ( I believe this is the case anyways). It's like saying since the 2004 Atlantic hurricane season was active maybe the 2005 season won't be...

aside from that, there are so many other variables (SAL, etc.,) that there is no way to know for sure...

The wet MJO is going to make an appearance in the Atlantic right on time when this happens. I believe that is one of the reason's why nothing is happening in the Atlantic right now. I have another question though, what is it that "we don't know for sure"? The article didn't exactly, directly state there would be a increase in storms but there should be since conditions would become more favorable.

[miamicanes177]

If wind shear does decrease to levels that are usual for late August then forget climatology. We could some serious major hurricanes in July.

[Chris_in_Tampa]

At the bottom of this page:
http://www.ssd.noaa.gov/PS/TROP/genesis.html
Is the current shear compared to normal for different regions. It has other genesis products on that page that are very informative.

[Recurve]

[whoops, wrong quote -edited]

That's a very interesting page I haven't seen before. Thanks for the link.

I like that 35-40 shear east of the Antilles. Wouldn't mind if that stayed around. (I'm one of the "please don't develop" people...living too close to the water).

[southerngreen]

everybody talks about the weather, but no one ever DOES anything about it!

we all anticipate the birth of the first big storm of the year (or we wouldn't be on this page) either because we fear it & want to be "ready" or because we enjoy watching the complex ballet as it develops and the strength & beauty of it - so, like little kids on a long car trip, we get a little crazy waiting!
(some of us crazier than others)
we post our observations & see what others have noticed. we can all learn something. enjoy the learning process while we don't have to be gathering supplies, hanging onto our weather radio & wondering which way we need to run! they will come soon enough, and there will always be someone who wishes they had more time to prepare.

[robbielyn]

I am leary of an active hurricane season and I will tell you why. There has been nothing normal about the weather this year. I have noticed here in fl the increase of winds and lack of rain this season. I see dry air probably related to the increase dust off of africa as a strong impedement like last year. Now if the shear abates then awesome but what if we keep having tutts? we may have a few fish storms but maybe that will be all.
With these tutts we have had a lot of dry air in the southeast and the atlantic and gulf which again has impeded storm formation and caused the drought conditions. Oh well, I guess it's a wait and see game but our rainy season is just in it's infancy. It's a whole month behind and I don't remember having all these tutts like we have had the last two seasons, so maybe it won't be so bad for the us this year. Also, is it my imagination or is hearing about the frequency of india typhoons unusual? I just don't remember hearing about them on twc so much as i have this year. I am sure they happen over there but they sure have made the front page. Is it due to the quiet so far in our neck of the woods or has there been an increase this year of typhoons over there?

[Frank2]

Cyclenall,

Weather patterns do oscillate (even the jetstream in it's own way, since it behaves hose-like), that's a given, so, hopefully if there's a change to low-shear, then, it'll reverse itself soon enough...

Since we are in a current long-term pattern of deep troughs in the Pacific northwest and Atlantic northeast (lows in the 40s and 50s up there tonight), my guess that this change in the tropical Atlantic is going to be only short-lived...

Guess if I lived where you live I'd be more interested in seeing a few big hurricanes, too...