QBO

[Guest]

Well, it seems that there has been an argumant across the WWW about the forecast I posted about the QBO?
This has been posted as a derogatory reply. Meaning, I am wrong!
This is an exerpt of NOAA's Hurricane Predictions for 2003:
"A secondary climate factor, anomalously easterly winds in the lower stratosphere, is expected to provide a slightly suppressing influence on overall Atlantic hurricane activity this season."
Ok, if this is so, the forecast in 1998 was an eastrly QBO also, but what happened?
We went into the season (June) with a gradual trend into a easterly QBO. Matter of fact, it became a rather strong easterly QBO. But, by August, there was a reverse in the trend.
By late August, through September, and into even November, we moved into a westerly QBO.
Oh, yeah the link! This has been widely used across the weather boards, and it doesn't seem that some have been reading it correctly.
http://www.cpc.ncep.noaa.gov/products/a ... /figt3.gif
If you look at 1995, it also was in a negative pattern, so with this said, the QBO is not as influental as some want to make it sound.
With a La Nina developing, and I'm more positive of this then even NOAA of La Nina developing, this will be one of the most influental enhancing parameters for this Hurricane Season!
What a easterly QBO can influence is, a stronger TUTT.

[weatherlover427]

Interesting info but what is a QBO? :o

[Steve]

Thanks Bob. Btw, I got to listen to the 5/14 show the other night. It was great as always.

Steve

[cycloneye]

Thank you Bob for posting the real truth of the QBO winds that some in the net haved been on the contrary of your forecast about that.I had some questions about that factor but you clarified those so again thank you.

[Guest]

A periodic alteration of easterly and westerly wind currents in the stratosphere, within about 12 degrees of the equator, with a period varying 24-30 months.
(courtesy of Glossary of Weather and Climate/Ira W. Greer/AMS)
In other words, it the flucuation of the wind currents near the equator that chnages every 24-30 months from easterly to westerly.
This year, some forecasters and enthusiasts have been saying that we will see a easterly QBO/ Quasi-Biennial Oscillation. But, due to what I've seen in recent years, we should continue to see a westerly influance of the QBO. There could be a brief period of easterly winds, but the over-all result will be a westerly phase, meaning additional favorable influance on tropical cyclogenesis.
At the moment, it is neutral, slightly easterly. If you look at the link above in the original post, you will see, the last strong easterly QBO we had was in 1998, and it shifted dramatically back to a westerly phase by the peak of the season.
The QBO is not a parameter that is widely understood, by me or let alone by forecasters. I do know one thing. The easterly QBO enhances the TUTT, and this can kill Tropical Systems.

[weatherlover427]

Thanks for the info, now I know.

[Steve]

Bob,

Lemme ask you a question. From the graphs in the link from your first post, 200mb Zonal Winds plot has an inverse correlation with the 500 mb chart anomoly. When the 200mb Zonal Winds were at their most negative standard deviation (1998), the 500mb temperature was at its highest.

Both are hedging back in their respective directions as 1998. But 1998 had the largest spikes in 20 years. The 30 and 50mb zonal winds are also spiking down@ -10.

So tell me in English what this means. I'm guessing it's something like the 200mb Zonal WInds and 30-50mb zoning winds when negative, that's from a westerly direction or does it have to do with the windspeed itself? And how high (in feet) is the 500mb temperature reading referring to, 10000 or so?

Thanks. Sorry for being ignorant on the technical atmospheric aspects. But to understand some of the stuff out there these days, I gotta know what it is that I'm reading.

Thanks for the explanation. You rule as always.

Steve(Old Metairie)

[vbhoutex]

Thanks Bob for posting that very educational information. It wasn't until recently that I even began to understand the QBO. Thanks to you I do now at least know what it is and understand more about it's influence on the tropics.

Keep up the great work you do and don't let the BA*^&rds get you down!!

[Guest]

I appericate this post as well because it explains the QBO.........I didnt know alot about it myself..........Thanks again Bob .

[The_Cycloman_PR]

Hello Bob!

Greetings from your puertorrican friend Cycloman. Thank's for your imput. I also believe QBO won't be as important as the other enhancing factors will be during this season. La nina is already in place, as I can see on the ENSO Anomaly page, and it's influence enhancing the Atlantic Basin hurricane activity this year may be stronger than a very weak easterly QBO as it's right now, even more...without El Nino's influence, the QBO and it's TUTT will have to work very hard to stop the tropical systems coming from Africa. Interesing season ahead!


Cycloman

[cycloneye]

Agree cycloman about the QBO winds not being a big factor to inhibit developments.I have a bad feeling about the caribbean region being visited by big canes comming from the CV area as the bermuda high wont let those CV systems go to fish to the north but time will tell if we in the caribbean will have canes in our vicinity but the important thing is to be prepared.

[Steve H.]

Hey Steve...lay off! Sounds like you know the answer to the question your asking Barometer Bob and waiting for the answer so you can attack I would rather have constructive discussion on this board rather than antagonism. You know the answer, you read the data. Draw your own conclusions

[Rainband]

Thanks for the explanation BOB!!! BTW you can post here alot more during cane season!!!! HINT HINT Just want to see you be an active poster thats all!!!

[Steve]

>>Hey Steve...lay off! Sounds like you know the answer to the question your asking Barometer Bob and waiting for the answer so you can attack I would rather have constructive discussion on this board rather than antagonism. You know the answer, you read the data. Draw your own conclusions

Pretty lame Steve H. I'll bet Barometer Bob and I go back as far as you and he do. It was a 100% legitimate question. I don't know if you think I'm a troll or something, but most of the mods - ticka included - can tell you otherwise. Why would I attack Barometer Bob? I know there are some web personality battles brewing right now, but I'm not involved in any of them and don't plan to be either.

I thought my quesitons were concise enough to not warrant a 'that's why you ordinary people shouldn't be looking at the data without consulting a professional meteorologist' calling down. What was I supposed to say, 'hey Bob, can you interpret those graphs?'

Unbelievable.

Steve

[Steve]

Waitaminute! Is this Steve H. from CHFC? You know me better than that. I see you aren't a mod, so I retract the statement about too many chiefs.

Honest to God, I was just looking for an explation from one of the pros or serious amateur mets on the site. I figured Bob might have the goods.

Steve

[Steve H.]

My bad Steve Thought you were being sarcastic and picking on Bob. My apologies. I should've read your whole post. Having a bad morning...guess I was the one looking for a fight. Again...sorry BTW, did you change your screen name? Didn't recognize you 'til I saw Old Metarie. I think I'll put my tail between my legs and crawl home now.

[Steve]

It's all cool. I ran across a couple of your old posts circa Lili/Isidore this morning. I love Bob, but I know where you're coming from since he took some hits on USWW and is embroiled with some of the regulars over there over his take on the QBO. I only use "Old Metaire" on USWW and when I go to Storm2k chat. I'm just Steve over here and at FLhurricane. No harm no foul whatsoever. I didn't realize it was even you until I saw those other posts and came back with my 'waitaminute.' No need to apologize whatsoever. Hope all is well btw.

Steve

[Steve H.]

OK, good...thanks Steve. Very busy here.....big proposal...lot of pressure...no excuse for me mouthing off. Should be a good season ahead Let's enjoy....now I can exhale

[Guest]

Ok, Steve here is your answer!
The QBO is represented in the 30-50MB chart, this is the wind direction. Positive is westerly, negative is easterly. Then you look at the 200MB zonal winds, this is where the vertical shear is located. Then the 500MB temp. When the vertical shear is strong, the temps rise from the surface, where you see the spike in the temps at 500MB.
Now go back to the chart, and look at it closely. The time of the peak is during the beginning of the year. the hash mark is June, the second half of the year. The peak occured before the season.
This graph is still old, and hasn't been updated, but it's a useful tool for deciding on a forecast for this season.
If you look again at the chart, you will see the rise in the 500MB temps, but the 30-50MB (QBO) is still almost neutral, or a weak easterly.
When you look further, the potential of a weak easterly, or neutral, or even a westerly QBO during the Atlantic Hurricane Season (June-November) is very common, being the potential of a Strong Easterly QBO is not. The Strong Easterly QBO is what kills Tropical Systems, not a weak easterly qbo.
Now, the levels of the 30MB= 50,000 to 60,000 feet
200MB=39,000 feet
500MB=17,500feet
So now, we have something to work with further. If the QBO affects the upper levels, then why does it interfere with tropical cyclonegenesis?
It's called shear, this we know. But, when the QBO is easterly and the lower levels are westerly(Trade Winds), the vertical shear is greater, thus not allowing for a substantiated convective pattern. Also, with warmer temps at 200MB, this doesn't allow for convection to develop, warming cloud tops!
So with warm cloud tops, and shear will we have a convective pattern? No!
But, again, this leads to the forecast of a westerly QBO DURING THE SEASON!!! Especially the months of August, September, and October!!
Now I give credit where credit is due. Hurricane Mike helped me with the MB Levels, being it's not an easy thing to remember.

Read this, and then let me know if you understand!
http://www.aoml.noaa.gov/hrd/Landsea/atlantic/
Difference between weak and strong easterly qbo:
http://www.aoml.noaa.gov/hrd/Landsea/au ... ure-3.html
I keep these type of links at hand, due to the forecasts I have posted over the past 3 years. This way, I can dig myself out of a hole, or bury myself with the dirt!

[Steve]

Thanks Bob. I'm looking forward to digging through those links after I get the kids off to bed. I'm weak on the technical processes which is the next step I need to work on in my own tropical development. Heh.

Thanks again.

Steve