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Re: 2011 Hurricane Season: Looking Ahead

Posted: Tue Apr 12, 2011 1:53 pm
by wxman57
The seasonal range ECMWF sea level pressure forecast is more revealing. Forecasting a lot higher pressures over the subtropical Atlantic than in 2010, indicating that the Bermuda High will be stronger and farther west in 2011.

Image

Re: 2011 Hurricane Season: Looking Ahead

Posted: Tue Apr 12, 2011 6:36 pm
by srainhoutx
Ed Mahmoud wrote:Can we get an SLP anomaly chart for JJA or JAS?

April 15th is not all that far away... ;)

Re: 2011 Hurricane Season: Looking Ahead

Posted: Wed Apr 13, 2011 7:35 am
by wxman57
Ed Mahmoud wrote:Can we get an SLP anomaly chart for JJA or JAS?
Ed,

The charts are issued once a month around the 20th-23rd with a valid time of the 15th. The new charts (MJJ) MAY be there by Friday the 22nd. They go out to 4 months, so they don't go out to the peak of the season yet. You can find the graphic I posted at the main Euro site:

http://www.ecmwf.int/

It's a bit hard to find. At the very top of that link, look under the "Products" header and select "Forecasts". Scroll down to the "Seasonal forecast" section and click "Forecast". A page with 2 bulleted links loads. Select the top link "Seasonal range forecast". On the next page, click on the map below "Spatial maps". Now you're nearly there.

In the left navigation frame, choose your parameter. You'll see "2m temperature", "mean sea level pressure", "rain" and "sea surface temperature". Click "mean sea level pressure". In the "Lead time" drop down menu choose 4 months. For the area, choose "South America". You're there! That was easy, wasn't it? There is some other good stuff there, too. Look around.

Re: 2011 Hurricane Season: Looking Ahead

Posted: Wed Apr 13, 2011 9:18 am
by wxman57
I'm here at your service, Ed. ;-)

Re: 2011 Hurricane Season: Looking Ahead

Posted: Thu Apr 14, 2011 10:23 am
by srainhoutx
Right on cue, or just a bit early, the Canadian is 'sniffing' out development in the Atlantic... :P

Re: 2011 Hurricane Season: Looking Ahead

Posted: Thu Apr 14, 2011 11:57 am
by srainhoutx
The GFS has been 'sniffing' disturbed weather across Central America for about a week now. That model develops a storm in the EPAC that crosses MX and into the BoC...more model fanatsy, but certainly a hint that we are nearing that time of year...

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Fri Apr 15, 2011 11:27 am
by Ptarmigan
NC State University 2011 Atlantic Tropical Cyclone Outlook
http://cfdl.meas.ncsu.edu/research/TCoutlook_2011.pdf

They use statistical models. Their prediction are:
13-16 named storms
7-9 hurricanes
3-5 major hurricanes

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Fri Apr 15, 2011 11:41 am
by wxman57
Nothing in the BoC on today's GFS.

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Sat Apr 16, 2011 7:52 am
by srainhoutx
The Euro, GFS, Canadian and the Nogaps suggest an easterly wave traversing across the Atlantic. It must be getting a bit closer to Tropical Season.

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Sat Apr 16, 2011 2:09 pm
by srainhoutx
The 12Z Euro suggests some spin with an area of disturbed weather near the Bahamas...
04162011 12Z Euro 12zeurotropical850mbVortSLP144.gif
04162011 12Z Euro 12zeurotropical500mbSLP144.gif

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Sat Apr 16, 2011 5:56 pm
by Ptarmigan
Is there a correlation between spring and summer and spring and August to October (Peak Season) El Nino? Apparently, there is. So, if we are in a La Nina, chances are it will warm to Neutral come summer and peak season.

Spring ENSO vs Summer ENSO
Two-tailed p value: < 0.001
Pearson's R statistic: 0.713
Degrees of Freedom (df): 139

Image


Spring ENSO vs. ASO ENSO
Two-tailed p value: < 0.001
Pearson's R statistic: 0.552
Degrees of Freedom (df): 138

Image

If the p-value is under 0.05, there is a significant correlation.

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Thu Apr 21, 2011 10:18 am
by srainhoutx
The first of the ECMWF Multi Model release to cover July/August/September mean sea level pressures suggests lower pressures across much of the Western part of the NALT Basin...

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Thu Apr 21, 2011 10:35 am
by srainhoutx
The precip data for the same timeframe suggests wetter than normal chances for MX/TX as well as the East Coast...

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Thu Apr 21, 2011 5:36 pm
by Ptarmigan
srainhoutx wrote:The precip data for the same timeframe suggests wetter than normal chances for MX/TX as well as the East Coast...
Let's hope so. :twisted:

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Fri Apr 22, 2011 7:29 am
by wxman57
srainhoutx wrote:The first of the ECMWF Multi Model release to cover July/August/September mean sea level pressures suggests lower pressures across much of the Western part of the NALT Basin...
Compare that forecast to last April's forecast for July-Sept. Look how much lower the pressure was forecast to be (and was) across the Atlantic. Current forecast indicates a stronger Bermuda High this year. Less named storms but less recurving well out to sea:
Image

Actually, I prefer this view. Here's August-October 2011. Lower pressures across the basin, but much higher than 2010:
Image

And here was the same forecast from last April:
Image

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Thu May 05, 2011 2:50 pm
by srainhoutx
A bit of ‘light reading’ for those so inclined. There is some good information regarding long range cyclogenesis modeling, improvements in HWRF and GFDL, future/current research project implantation and much more…

http://www.ofcm.gov/ihc11/linking_file_ihc11.htm

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Fri May 06, 2011 12:03 pm
by unome
ImpactWeather's updated hurricane forecast on YouTube: 14 / 8 / 4

http://www.youtube.com/user/impactweath ... D4HWWnL74U

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Fri May 06, 2011 2:15 pm
by Ptarmigan
unome wrote:Impact Weather's updated hurricane forecast on YouTube: 14 / 8 / 4

http://www.youtube.com/user/impactweath ... D4HWWnL74U
The analog years are 1989, 1996, 2000, 2001, and 2008.

1989, 2001, and 2008 were not good years for Texas.

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Fri May 06, 2011 2:48 pm
by srainhoutx
As many will remember, drought conditions were present in 2008 as well. While no one knows with any certainty where any storms will go, the signals suggest we will spend many an hour tracking the tropics this year. Only 25 days away until the start of the NALT Tropical Season 2011.

Re: 2011 N Atlantic Hurricane Season: Looking Ahead

Posted: Fri May 06, 2011 3:12 pm
by wxman57
Yes, 2008 does appear to be the very best analog for 2011. I expect our current drought to last through July, then watch out from the tropics! With any luck, we'll just get some rain from disturbances. However, I do suspect we'll be threatened (not necessarily hit) by a hurricane this season.