Analog Seasons
How do they base a season on analog seasons and how far do they go back? For example, I hear this season's analog season is 1995, 1998, and 2005. Some seasons prior to 1950 remind me of post 1950 season. For example, 1886 reminds me of 1985, 2004, and 2008, while 2005 reminds me of 1933.
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wxman57
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I assume you're talking about analog years for the hurricane season? If you check out a few of the Gray/Klotzbach predictions there are sections on what constitutes an analog. See page 22 of last December's 2010 outlook:
December 2009 Outlook for 2010:
http://hurricane.atmos.colostate.edu/Fo ... ec2009.pdf
So for the December outlook, the primary analog was years coming out of an El Nino. But for other outlooks as the season approaches, more analogs are added. Check out page 17 of the April Outlook:
April 2009 Outlook:
http://hurricane.atmos.colostate.edu/Fo ... pr2009.pdf
What we look for are similar climatological characteristics compared to past years. Some may include:
1. Current El Nino / La Nina situation and trends
2. Similar AMO (Atlantic Multidecadal Oscillation). Basically SSTs across the basin
3. Similar PDO (Pacific Decadal Oscillation). SSTs in the NE Pacific
4. Perhaps similar mean SLPA across the basin (Sea Level Pressure Anomalies)
That assumption is that if the current spring patterns can be identified as very similar to a year in the past, then we might expect development and tracks to be similar to that past season.
December 2009 Outlook for 2010:
http://hurricane.atmos.colostate.edu/Fo ... ec2009.pdf
So for the December outlook, the primary analog was years coming out of an El Nino. But for other outlooks as the season approaches, more analogs are added. Check out page 17 of the April Outlook:
April 2009 Outlook:
http://hurricane.atmos.colostate.edu/Fo ... pr2009.pdf
What we look for are similar climatological characteristics compared to past years. Some may include:
1. Current El Nino / La Nina situation and trends
2. Similar AMO (Atlantic Multidecadal Oscillation). Basically SSTs across the basin
3. Similar PDO (Pacific Decadal Oscillation). SSTs in the NE Pacific
4. Perhaps similar mean SLPA across the basin (Sea Level Pressure Anomalies)
That assumption is that if the current spring patterns can be identified as very similar to a year in the past, then we might expect development and tracks to be similar to that past season.
Yes, it was analog years for hurricane seasons. Thanks for the clear explanation!
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wxman57
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Right, Ed, analog doesn't mean carbon copy. No one is suggesting that we'll see 28 named storms in 2010 because 2005 may be an analog year.
Last year, the ECMWF predicted that pressures in the Basin would be 1-2 standard deviations above normal (stronger Bermuda High). This certainly came true. The higher pressures produced much stronger easterly trade winds, resulting in a variety of negative impacts (as far as development) such as stronger low-level shear, a significant increase in dry air moving off the west coast of Africa and more significant upwelling of water in the main development region, resulting in cooler SSTs in the MDR. I don't really think that El Nino was as big a factor as that stronger area of high pressure.
For 2010, the ECMWF is predicting lower than normal pressures across the Atlantic Basin. Already, we can see that SSTs in the MDR are significantly warmer than last year. Wind shear is down, and dry air is not as much of a factor. The Euro is predicting much higher than normal pressure in the East Pacific this season. That means sinking air there and more rising air in the Caribbean for 2010. El Nino will be on its way out, as well.
So most factors are currently pointing toward a significantly more active season in 2010. Storms may develop farther east and not be ripped apart by shear this year. As with the analog years, about half the storms may recurve safely out to sea east or northeast of the Caribbean. But the half that don't recurve early could cause major problems for the Caribbean, the southeast U.S. and the Gulf Coast.
I'm adding a few items to my hurricane kit this year. Got an Auvio 3.5" digital TV from Radio Shack that runs on 4 AA batteries vs. a rechargeable lithium-ion cell that needs AC power to recharge. Perhaps we can initiate a "stickied" thread on hurricane preparedness? I can post one of my presentations along with links to lots of good info and products.
Last year, the ECMWF predicted that pressures in the Basin would be 1-2 standard deviations above normal (stronger Bermuda High). This certainly came true. The higher pressures produced much stronger easterly trade winds, resulting in a variety of negative impacts (as far as development) such as stronger low-level shear, a significant increase in dry air moving off the west coast of Africa and more significant upwelling of water in the main development region, resulting in cooler SSTs in the MDR. I don't really think that El Nino was as big a factor as that stronger area of high pressure.
For 2010, the ECMWF is predicting lower than normal pressures across the Atlantic Basin. Already, we can see that SSTs in the MDR are significantly warmer than last year. Wind shear is down, and dry air is not as much of a factor. The Euro is predicting much higher than normal pressure in the East Pacific this season. That means sinking air there and more rising air in the Caribbean for 2010. El Nino will be on its way out, as well.
So most factors are currently pointing toward a significantly more active season in 2010. Storms may develop farther east and not be ripped apart by shear this year. As with the analog years, about half the storms may recurve safely out to sea east or northeast of the Caribbean. But the half that don't recurve early could cause major problems for the Caribbean, the southeast U.S. and the Gulf Coast.
I'm adding a few items to my hurricane kit this year. Got an Auvio 3.5" digital TV from Radio Shack that runs on 4 AA batteries vs. a rechargeable lithium-ion cell that needs AC power to recharge. Perhaps we can initiate a "stickied" thread on hurricane preparedness? I can post one of my presentations along with links to lots of good info and products.
I have never seen a carbon copy. If such a thing happened, that would be a 1 in a billion chance! 
I do remember Charley and Frances of 1998. Charley dumped 18 inches in Del Rio, whole Frances was a huge rainmaker for Houston. Georges and Mitch were bad. Mitch would be the deadliest besides the 1780 Hurricane. Mitch was the most intense prior to Katrina. 2008 was memorable for us because of Ike.
1995-Active all the way!
1998-Started early, but went quiet and than active again.
2005-Active all the way! Need I say more.
2008-Active all the way!
I don't think we will see a repeat of 2005 this season. I think 1887 and 1933 were just as active as 2005.
I do remember Charley and Frances of 1998. Charley dumped 18 inches in Del Rio, whole Frances was a huge rainmaker for Houston. Georges and Mitch were bad. Mitch would be the deadliest besides the 1780 Hurricane. Mitch was the most intense prior to Katrina. 2008 was memorable for us because of Ike.1995-Active all the way!
1998-Started early, but went quiet and than active again.
2005-Active all the way! Need I say more.
2008-Active all the way!
I don't think we will see a repeat of 2005 this season. I think 1887 and 1933 were just as active as 2005.
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srainhoutx
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When you complete your "Hurricane Preparedness Presentation" for the Forum, we will "sticky" the Topic wxman57.wxman57 wrote:Right, Ed, analog doesn't mean carbon copy. No one is suggesting that we'll see 28 named storms in 2010 because 2005 may be an analog year.
Last year, the ECMWF predicted that pressures in the Basin would be 1-2 standard deviations above normal (stronger Bermuda High). This certainly came true. The higher pressures produced much stronger easterly trade winds, resulting in a variety of negative impacts (as far as development) such as stronger low-level shear, a significant increase in dry air moving off the west coast of Africa and more significant upwelling of water in the main development region, resulting in cooler SSTs in the MDR. I don't really think that El Nino was as big a factor as that stronger area of high pressure.
For 2010, the ECMWF is predicting lower than normal pressures across the Atlantic Basin. Already, we can see that SSTs in the MDR are significantly warmer than last year. Wind shear is down, and dry air is not as much of a factor. The Euro is predicting much higher than normal pressure in the East Pacific this season. That means sinking air there and more rising air in the Caribbean for 2010. El Nino will be on its way out, as well.
So most factors are currently pointing toward a significantly more active season in 2010. Storms may develop farther east and not be ripped apart by shear this year. As with the analog years, about half the storms may recurve safely out to sea east or northeast of the Caribbean. But the half that don't recurve early could cause major problems for the Caribbean, the southeast U.S. and the Gulf Coast.
I'm adding a few items to my hurricane kit this year. Got an Auvio 3.5" digital TV from Radio Shack that runs on 4 AA batteries vs. a rechargeable lithium-ion cell that needs AC power to recharge. Perhaps we can initiate a "stickied" thread on hurricane preparedness? I can post one of my presentations along with links to lots of good info and products.
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March 1st coming up ala 2K. I think we should open a prediction thread for prelim numbers and finalize it by May 1st....Steve what do you think....
I think we should. March would give us a good idea of how active the season would be.Paul wrote:March 1st coming up ala 2K. I think we should open a prediction thread for prelim numbers and finalize it by May 1st....Steve what do you think....