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A June 1 surprise: Tropical Storm Barry

By: Dr. Jeff Masters, 9:25 PM GMT on June 01, 2007

The hurricane season of 2007 officially began today, and we officially have our second surprising named storm of the season--Tropical Storm Barry. Barry is highly unusual in that it developed in the presence of strong wind shear--about 20-40 knots. I've never seen a tropical storm form under more than about 25 knots of wind shear. Satellite loops show a well-defined circulation to the west of Key West, and heavy thunderstorm activity popping up on the north side of the center. Barry is over the warm 82F waters of the Loop Current, and will gradually traverse over colder waters as it moves north and then north-northeast over the next day. The circulation of Barry is now visible on the Key West radar. Pulaski Shoal Light just to the northeast of Barry's center recorded sustatined winds of 35 mph, gusting to 40mph, at 2pm EDT today.

The Hurricane Hunters are still in Barry, and found that the pressure continues to drop--997 mb at 6:30pm EDT. The winds are also increasing, with the top winds at 77 mph at flight level of 1,500 feet at 5pm EDT. This corresponds to peak surface winds of about 60 mph. However, these winds are not representative of the storm, and likely occurred in the outflow from the strongest thunderstorm near the center. NHC is justified in bringing the intensity up to just 50 mph in their 8pm advisory.

I don't expect Barry will intensify to a hurricane, due to increasing wind shear and cooler waters underneath. Barry should mostly be a blessing for Florida, who can use the 3-6 inches of rain the storm is likely to bring. Some storm surge flooding may occur along the same stretch of coast affected by Tropical Storm Alberto last year. However, no damage was reported due to Alberto's storm surge, and Barry's should be roughly the same magnitude. Perhaps the greatest threat from Barry will be tornadoes that could form Saturday afternoon over Florida.

Another Hurricane Hunter aircraft is scheduled to investigate Barry at 8am EDT.

Figure 1. Total rainfall from the Tampa Bay radar.

A sign of things to come?
The hurricane season of 2007 is in second place for the earliest year that the second named storm occurred. The record is held by 1887, when the second named storm formed on May 17. Third place is held by 1934, when the second storm of the year formed on June 4. The second storm of 1934 was also the worst June hurricane on record. It hit Central America as a Category 1 hurricane, dropping up to 25 inches of rain on Honduras, triggering landslides that killed 3,000 people.

There is no relationship between high activity early in hurricane season and high activity during the main August-October peak of the season. For example, the 1934 hurricane season turned out to be an ordinary season with 11 named storms, 6 hurricanes, and no intense hurricanes.

June outlook
My outlook for the first two weeks of June was posted earlier today.

Radio play
National Public Radio's The Story program will be airing a long interview with me today about my flight into Hurricane Hugo in 1989. The show is carried on NPR stations in MI, WI, IL, IN, IA, MN, NC, NY, VA, and WI, and airs live today at 1pm or 8pm EDT. Check http://thestory.org/Stations for local stations and times. You can also listen live on the Internet at NPR station wunc.org in North Carolina. The host, Dick Gordon, is a very gifted interviewer, and it should be an interesting program. The MP3 of the interview is at http://thestory.org/archive/the_story_263_Hunting_Hurricanes.mp3.

Last night, I was guest on the Barometer Bob Show. You can listen to a podcast of my 50-minute spiel at http://www.barometerbobshow.com/podcast/.

Jeff Masters

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