WunderBlog Archive » Category 6™

Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.

Jet stream moved northwards 270 miles in 22 years; climate change to blame?

By: Dr. Jeff Masters, 4:11 PM GMT on June 05, 2008

Climate change is forcing the jet stream higher and closer to the pole in both the Northern and Southern Hemisphere, according research published this April in the journal Geophysical Research Letters. In their paper, "Historical trends in the jet streams", researchers Cristina Archer and Ken Caldeira of Stanford's Carnegie Institution of Washington analyzed data from 1979-2001, and found that the Northern Hemisphere jet stream moved northward at approximately 125 miles per decade (270 miles during the 22-year period of the study). The jet moved higher by 5-23 meters during this period, and the wind speeds decreased by about 1 mph. Archer and Caldeira's study confirms other research showing a poleward movement of the jet stream in recent decades (Fu et al., 2006; Hu and Fu, 2007). All of these changes are consistent with the behavior of the jet stream predicted by global warming theory. For example, Lorenz and DeWeaver (2007) found poleward shifts of the jet stream by 2100 in the forecasts of 15 climate models used to formulate the "official" word on climate, the 2007 Intergovernmental Panel for Climate Change (IPCC) report. However, the authors were careful not to say how much of this shift in the jet stream was due to natural causes versus human-caused climate change. It is unknown if the jet stream has natural decades-long changes in its path that could account for the observed poleward shift.


Figure 1. The jet stream is located where the strongest winds at the top of the troposphere are found (35,000-45,000 feet high, 200-300 mb in pressure).

Archer and Caldeira note that "These changes in jet stream latitude, altitude, and strength have likely affected, and perhaps will continue to affect, the formation and evolution of storms in the mid-latitudes and of hurricanes in the sub-tropical regions." They don't specify what these changes might be. There is very little research that has been done suggesting how changes in the jet stream might affect hurricane formation and strength. One effect we may begin to see in coming decades is a reduction and/or delay in the number of hurricanes that recurve northward out to sea. Recurvature occurs when a hurricane begins to "feel" the westerly winds of the jet stream. As the jet stream continues to move northward and weaken as the globe warms, we can expect that hurricanes moving though the Caribbean will be less likely to recurve, resulting in more hurricane strikes in Mexico and Central America. Unfortunately, the quality of the Atlantic hurricane database for non-U.S. landfalls is not very good, and it will be several decades before we will be able to tell if the number of hurricane landfalls in Mexico and Central America is increasing due to a poleward shift in the jet stream.

References
Fu, Q., C. M. Johanson, J. M. Wallace, and T. Reichler (2006), Enhanced mid-latitude tropospheric warming in satellite measurements, Science, 312, 1179, doi:10.1126/science.1125566.

Hu, Y., and Q. Fu (2007), Observed poleward expansion of the Hadley circulation since 1979, Atmos. Chem. Phys. Disc., 7, 9367.9384.

Lorenz, D. J., and E. T. DeWeaver (2007), Tropopause height and zonal wind response to global warming in the IPCC scenario integrations, J. Geophys. Res., 112, D10119, doi:10.1029/2006JD008087.

Jeff Masters

Climate Change

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

1490. TampaSpin 8:59 AM EDT on June 09, 2008
After the heating of the day over florida, that ULL should help alot of storms pop.

House i think just the general strong severe Thunderstorms. I doubt tornados will be around but, that can never be ruled out in Florida.
I posted a link to radar imagery earlier...can people see my posts or am I being ignored =[
The moisture from 91L is following the jet right up the to plains and midwest, we who live there don't need any more moisture, we are overflowing,

Action: | Ignore User
1492. weathermanwannabe 9:00 AM

Lol....That outlook was a bit painful to read through.....Just get to the point right?....


Yeah, GM wannabe.
The only thing that stays the same: Change

Working on the boat today - but will check during "sun breaks". Don't want that ULL to sneak up on me. LOL
1508. NEwxguy
GM, all,summer has arrived in the northeast!!!
I think that the few storms in climatologically speaking develop in June are usually in the western caribbean, there have been exceptions like tropical storm Ana, in 79. You all know that the eastern caribbean is hostile because the westerlies this time of the yearwill killed the waves coming from Africa. I don't think anything happening on out of the ordinary.
"A strong (996 mb) extra-tropical open ocean low way out in the northern mid-Atlantic near 40N/45W will spin away through the first half of the work week as it drifts slowly north. This strong low has a tight fetch of gale force NE wind that may allow a small/inconsistent long period ground swell to work its way to Florida into mid-week."

From local surf report-I wouldn't count on this, forget it...it's flat out there.
1511. newt3d
Hurricane season being a bust = good, right? Why is everybody talking about it so negatively?

That aside, it's way too early to tell. Also, it only takes one storm. Hurricane Andrew didn't form until August 22nd.
1512. Buhdog
Saw a funnel cloud yesterday in the Ft Myers area...it did not touch down the period of time I could see it....There was very little in rotation...

You ever see one of those funnels that come down and barely spin? They look like a dipping cloud until you see a small turn...Common in Florida.
Without being a Smart-Butt,,,,,but what would be a defination in most peoples eyes as a tropical season bust......just wondering.
1514. OUSHAWN
Haven't had a chance to really take a look at it closely but what is going on in the SW Caribbean and the blow up of activity down there...anything to it?
1490. TampaSpin 12:59 PM GMT on June 09, 2008 Hide this comment.
After the heating of the day over florida, that ULL should help alot of storms pop.


Agree with that. Coverage will be much greater today with decent upper level support. As soon as the sea breeze moves in it should be go time.
1518. vortfix
Twister damages 53 mobile homes in Lee

7:47 a.m.
The National Weather Service is sending a representative to assess the damage in North Fort Myers caused by yesterdays tornado.

Residents should expect more bad weather today, said Terry Pye, North Fort Myers fire chief.

Pye said power was quickly restored last night and companies were already out last night to help residents with cleanup.


Photobucket

Photobucket

Only here is the word "bust" used to describe the absence of devastating destruction, injury and death......
1520. beell
What's the word on the activity centered over the NE Yucatan?
1516. jphurricane2006 10:07 AM EDT on June 09, 2008

JP, last year many called last year a bust....those people should tell that to the people in Mexico.....no bust there.
after going to the beach this weekend with about 100,000 jelly's in the GOM...can anyone compare the GOM temps from now to the 04 season?? the temps are more late July & August...not June....talka bout a sauna...wouldn't take much for anything to fire up like it did last year off the coast of Texas
34A would cause little injury, but 46DDD could knock one out.........LMAO
1525. vortfix
MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
230 AM EDT MON JUN 09 2008


TRPCL WAVE CREST MOVES W THROUGH BAY OF CAMPECHE TODAY AND
TONIGHT S OF 23N HAS PLENTY OF MOISTURE AVAILABLE FOR CONVECTION
AND ENTERING A LESS ADVERSE UPPER LEVEL ENVIRONMENT WHICH COULD
NOW ENHANCE INTENSIFICATION...BUT WOULD BE MOSTLY OVER INLAND
MEXICO.
1526. Patrap
Wonder How Jeff Masters Hiking went?

I spect we may here from him Later today.
1512. Buhdog 1:57 PM GMT on June 09, 2008
Saw a funnel cloud yesterday in the Ft Myers area...it did not touch down the period of time I could see it....There was very little in rotation...


1518. vortfix 2:14 PM GMT on June 09, 2008
Twister damages 53 mobile homes in Lee

7:47 a.m.
The National Weather Service is sending a representative to assess the damage in North Fort Myers caused by yesterdays tornado.

Looks like these 2 posts are contridictory. (sp?)
this is crazy


when you all say that hurricane season is a bust and when its olny the 1st two weeks of june


dont make hurricane season mad at you it could come back right at you for saying it was a bust


this is crazy
1528. Tazmanian



Me thinks it was a joke Taz.
1520. beell 2:16


Is it a naked swirl?
Moisture coming to the GOM soon.
tks tampa...lord knows we need some moisture...sticky isn't even the word to use..
I would say that the poor people in Mexico would not agree that this season is a bust as they have already been affected by this hurricane season and they are receiving additional rain that they don't need. It looks like more is on the way and they are already flooded out.
So I guess it depends on where you are on whether this season is going to be a bust or not. I hope it's a bust at my house.
1526. Patrap 2:24 PM GMT on June 09, 2008
Wonder How Jeff Masters Hiking went?

I spect we may here from him Later today.



Hi Pat, did he say 1 or 2 weeks?
How can anyone say it's a bust already?? apparently none of you that think this live on the coast line or have NEVER been through a storm...the REAL season hasn't even stated yet..
1537. beell
1530.
Don't think it is all that yet. Been watching a bit of a shear zone that has been moving W for the last few days between Cuba and Jamaica.

Probably nothing-just looks "funny"
1538. Patrap
Bu
Probably nothing-just looks "funny"



Its got a lil' "twist" to it...hehe
1538. Patrap 2:49 PM GMT on June 09, 2008
Bu

huh?
1541. NEwxguy
what a swirl out in the north atlantic.

1542. guygee
1500. TampaSpin 1:25 PM GMT on June 09, 2008

I know some on here use firefox...which i know little about.....but, is there anything that updates the blog without having to refresh it all the time.

Hey Tampaspin...longtime Mosaic/Netscape/Mozilla/Firefox user here, going to switch to SeaMonkey soon. But I tried this out for IE6 auto refresh and it works great (Thanks to Chippy_Minton over at the MoneySavingExpert.com Forums).

1. Copy the VB code below into Notepad.

2. Save the file to your desktop named "IErefresh.vbs" (without the quotes)

3. Double-click on the IErefresh.vbs icon to run the script. A small window will pop up and prompt for the URL. The http:// part is optional. Since we are in paged view, I think it is important to enter the URL in this form:

www.wunderground.com/blog/JeffMasters/comment.html?entrynum=958&tstamp=200806#commenttop

I think that #commenttop part at the end keeps you from getting stuck on a page.

4. Next, the program will prompt for the number of seconds for the interval of the auto-refresh. The default is 60 seconds. Be careful because if you auto-refresh while you are typing a comment you might lose your comment (not sure of what happens then).

5. The script automatically brings up IE for you and auto-refreshes. Works just fine.

6. Alternately, check out:
http://urlrefresh.harrybailey.com/


Note: The code I meant to post looked fine in the preview, and tested out, but when I posted it to the blog it got mangled. Please look ahead to post #1563 in this blog for the link to the original code that can be copied into Notepad.
1543. Buhdog
1527. TEXASYANKEE43 2:26 PM GMT on June 09, 2008
1512. Buhdog 1:57 PM GMT on June 09, 2008
Saw a funnel cloud yesterday in the Ft Myers area...it did not touch down the period of time I could see it....There was very little in rotation...


1518. vortfix 2:14 PM GMT on June 09, 2008
Twister damages 53 mobile homes in Lee

7:47 a.m.
The National Weather Service is sending a representative to assess the damage in North Fort Myers caused by yesterdays tornado.

Looks like these 2 posts are contridictory. (sp?)


Wow!! I can't believe it must have already done damage to the mobile homes and gone back to funnel cloud stage...I had not seen the news yet. How do these things find Mobile parks so easily?
1542. guygee 11:00 AM EDT on June 09, 2008

A little too complicated for us "older" men; I prefer to hit the refresh button so I know where I last left off when I had to take a bathroom break, which, is pretty frequently these days..........Lol
"How can anyone say it's a bust already?? apparently none of you that think this live on the coast line or have NEVER been through a storm...the REAL season hasn't even stated yet."

How can anyone not grasp that the guy was just joking?

Is two weeks into the future about the limit presently in predicting upper level wind patterns?
How do these things find Mobile parks so easily?

Mobile homes are tornado magnets!
1547. NEwxguy
the building here at work is down,can you say preventive maintenance before there is a heatwave??
1547. NEwxguy 3:10 PM GMT on June 09, 2008
the building here at work is down,can you say preventive maintenance before there is a heatwave??


You talkin' 'bout the ac?
1549. guygee
Re: 1544. weathermanwannabe

LOL, weathermanwannabe, I'm rollin' down that second half of the century now too!

Pretty easy really, copy, paste, save, double-click...but personally I'm with you, I manually refresh...that is probably why I often end up talking to people that left 20 minutes ago, lol.
Post 1528 - thank you for being the voice of reason, Taz.
1549. guygee 11:12 AM EDT on June 09, 2008..LOL
1553. NEwxguy
1548. TEXASYANKEE43 3:12 PM GMT on June 09, 2008
1547. NEwxguy 3:10 PM GMT on June 09, 2008
the building here at work is down,can you say preventive maintenance before there is a heatwave??


You talkin' 'bout the ac?

Yeh,its 87 deg inside our office
mobile homes are just easily distroyed and unsafe. An EF0 can do reprehensible damage to a mobile home but that same EF0 hits a neighborhood and you wont even see a shingle out of place.
1555. NEwxguy
lol,just realized I didn't say building a/c,the building is still standing
Yeh,its 87 deg inside our office

I know what you mean. Our doors are open.

87.1 °F / 30 °C
Mostly Cloudy
Humidity: 62%
Dew Point: 72 °F / 22 °C
1554. earthlydragonfly 3:15 PM GMT on June 09, 2008
mobile homes are just easily distroyed and unsafe. An EF0 can do reprehensible damage to a mobile home but that same EF0 hits a neighborhood and you wont even see a shingle out of place.


This is true but some mobile homes are well constructed. My grandma has lived in the same mobile home in the middle of an open field (where all the wind can hit it full force) for about 13 years. It went through Katrina (she lives about 45 min's north of New Orleans), Rita, Lili, and other hurricanes, and even a tornado that knocked numerous trees down around it. Still standing strong. Never lost a shingle, or siding for that matter. The skirting blew off, but that happens when the wind gets over 40mph. It's a single wide 16 X 80.

It's just a simple free standing mobile home. The only anchorage it has, besides it's tie downs, is the two car carport attached on one end. Now the carport has seen some damage in it's time, but that's about it.
Tornados hunt down trailer parks. It's their job! j/k
ULL


Invest 92E


Powerful Atlantic Storm
CCHS - Is that first image you posted a wave that needs to be watched?

I noticed it this morning on the still image of the NHC site, but when I tried to load the loop on my computer it didnt work. I think it has something to do with our system restrictions here at work and the whole JAVA thing.
New blog
1563. guygee
Re:1542. guygee 3:00 PM GMT on June 09, 2008

Sorry All, especially TampaSpin, when I previewed the script I copied and tested it and it worked just fine, but when it posted it got corrupted somehow. I reposted an image of the script but that is barely readable.

If you scroll down this link you will find the original post from Chippy_Minton with the code that you can just copy into Notepad.
that there
Powerful Atlantic Storm
must be a powerful
cat 78 atleast...