Getting Ready For The Tropical Season

May is here, which means hurricane season is just around the corner. The season “officially” runs from June 1 through the November 30, but early systems have formed in May before. The core of the season is August, September, and early October, when sea surface temperatures in the Atlantic basin peak.

Dr. William Gray at Colorado State University, who likes to forecast tropical activity (and has been doing it for 22 years), expects 13 named tropical storms in 2005, of which seven become hurricanes. Of those seven, three are forecast to be intense hurricanes. He notes he might raise these numbers up a tad if he can be sure El Nino conditions will not develop. His probabilities of at least one major hurricane landfall look like this: The entire U.S. coastline: 73%; the U.S. east coast including the Florida peninsula: 53%; the Gulf coast from Brownsville, Texas to the Florida panhandle: 41%.

We received a note from the National Hurricane Center that they will not be changing the format of their track graphics this season. There was some concern that the public was focusing too much on the center line of the forecast tracks, and not looking at the “margin of error” fans coming from those center lines. Several options were discussed, based on input from the public and EMA officials there will be no change this year.

Names for tropical storms in 2005: Arlene, Bret, Cindy, Dennis, Emily, Franklin, Gert, Harvey, Irene, Jose, Katrina, Lee, Maria, Nate, Ophelia, Philippe, Rita, Stan, Tammy, Vince, and Wilma. Hurricane names repeat every six years; this was the exact list used in 1999 (no hurricanes were strong enough in 1999 for the name to be retired).
Posted by  
on May 4, 2005, 6:12 am
I see where all four major hurricanes from last year have had their names retired, inlcuding our good buddy Ivan. They should chance his retired name to Ivan the Terrible.

Any chance, since Charley is retired, that Clyde will become the C storm to replace it? Then, we could have Bonnie and Clyde going at the same time. Just a thought, and a bad one at that...

Reply to this comment
Posted by  
on May 26, 2005, 10:47 am
I recognize that the Atlantic Basin gets the most attention because of the fact tropical systems typically move from east to west and threaten the East and Gulf coasts of the United States. But I am a little irritated that not more attention (in some cases none at all) is paid to the tropical cyclones of the Eastern Pacific. These systems, while not bringing strong winds and high waves to the western U.S. nonetheless can pose significant rainfall threats not only to the southwestern states of California, Arizona and New Mexico but also to the Central Plains. As a retired NWS meteorologist from Topeka, Ks. we had significant rainfall events (10 to 20 inches each) over Oklahoma and southeast Kansas from Hurricanes Tico, Paine, and Waldo in the 1980s. The typical scenario runs like this: A cold front moves south associated with a northern jet stream upper trough, then becomes stalled out in a northeast-southwest fashion over the Central Plains beneath a southwesterly sub-tropical upper flow. Precipitation initially occurs with the frontal system followed by more precipitation as upper level moisture is advected northeast over the frontal zone from an Eastern Pacific tropical cyclone, then as the cyclone recurves and moves northeast toward Mexico it tends to get sheared off with the potent remaining upper portion and its copious amounts of moisture move northeast over the stalled frontal system to produce the final - and most intense - blow. These events typically occur during later September or October when cold air is becoming more significant at the lower levels but the tropics are still warm with copious amounts of moisture -- the perfect combination to "squeeze the limits" out of the atmosphere. These events have been documented in a NWS Central Region Technical Attachment published in 1984 as I recall. On a sidenote it is interesting that the first tropical cyclone of the Eastern Pacific 2005 season (Adrian) has already had an impact on the Americas courtesy of its unusual northeast motion into El Salvador instead of the more usual motion toward the westnorthwest.

Larry

Reply to this comment