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An early season Atlantic named storm looking less likely

By: Dr. Jeff Masters, 2:46 PM GMT on May 15, 2009

The possibility of a May subtropical storm forming near Florida next week now appear dim, according to the latest suite of runs by the GFS, UKMET, NOGAPS, and ECMWF global dynamical computer models. Yesterday's runs indicated that a small area of low shear air might develop over Florida next week, between the polar jet stream to the north and the subtropical jet stream to the south. However, the latest set of runs are showing a much reduced area of low shear, too small for a subtropical storm to form. Perhaps a better chance for a subtropical storm to form is in the mid-Atlantic a few hundred miles east of Bermuda. There, a large upper-level cold low has cut off from the jet stream, and it may spin in place long enough over the next week to develop a warm core and be classified as Subtropical Storm Ana. It is unlikely that a subtropical storm forming that far out in the Atlantic this early in the year would pose a threat to any land areas, with the possible exception of Bermuda.

Climatology of early-season Atlantic tropical cyclones
Tropical storms are uncommon in the Atlantic before June 1, with only 26 named storms on record between 1851 - 2008. Five of these have made it to hurricane strength, and only one--Hurricane Able of 1951--made it to major hurricane status. Last year's Tropical Storm Arthur may be the deadliest May tropical cyclone on record. Though only a 40 mph tropical storm at landfall, Arthur killed five people in Belize and caused $78 million in damage. Three early-season storms have brought hurricane-force winds to land. The March 1908 hurricane swept through the northern Lesser Antilles Islands as a Category 1 or 2 hurricane, destroying at least 24 boats and causing damage to buildings on St. Bartholomew. Hurricane Able of 1951 brought sustained winds of 90 - 95 mph to the northern Bahama Islands, but caused little damage. Hurricane 2 of May 1908 hit North Carolina's Outer Banks as a Category 1 hurricane, but also caused little damage.

Figure 1. Tracking map for the earliest hurricane to make landfall, the March 1908 hurricane in the northern Lesser Antilles Islands.

List of all early season (formed in January - May) Atlantic named storms
May 31, 2008: Tropical Storm Arthur
May 6, 2007: Subtropical Storm Andrea
April 18, 2003: Tropical Storm Ana
April 21, 1992: Subtropical Storm 1
May 6, 1981: Tropical Storm Arlene
January 18, 1978: Subtropical Storm 1
May 21, 1976: Subtropical Storm 1
May 23, 1972: Subtropical Storm Alpha
May 17, 1970: Hurricane Alma (Category 1)
May 28, 1959: Tropical Storm Arlene
February 2, 1953: Tropical Storm Alice
May 25, 1952: Tropical Storm 1
May 15, 1951: Hurricane Able (Category 3)
May 22, 1948: Tropical Storm 1
May 19, 1940: Tropical Storm 1
May 27, 1934: Tropical Storm 1
May 14, 1933: Tropical Storm 1
May 5, 1932: Tropical Storm 1
May 13, 1916: Tropical Storm 1
May 24, 1908: Hurricane 2 (Category 1)
March 6, 1908: Hurricane 1 (Category 2)
May 27, 1890: Tropical Storm 1
May 16, 1889: Hurricane 1 (Category 1)
May 17, 1887: Tropical Storm 2
May 15, 1887: Tropical Storm 1
May 30, 1865: Tropical Storm 1

I'll have an update over the weekend if the models indicate a renewed tropical threat; otherwise, have a great weekend, and I'll be back on Monday.

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.

Reader Comments

1001. Drakoen
ECMWF 12z similar to the GFS 12z
1002. IKE
That ECMWF has landfall Saturday night.
1004. Drakoen
Quoting hurricane23:
Drak thought i'd pass along this newly developed site for florida a friend at FSU put together.Model data from the WRF/GFS/NAM are available. VIEW HEREAlso sst daily output.

Thanks. Looks pretty sweet.
1005. cg2916
Quoting reedzone:
Good afternoon everyone, models have become somewhat aggressive with our "possible" Ana. Most of them target the Panhandle of Florida (sorry IKE). NOGAPS takes it more west, heading to Texas if I was reading that correctly. Here's what I think, convection is organizing quite well under 30 knots of shear today, Invest 90L might show up either tonight or tomorrow if organization continues to happen. Nobodies mentioning about our cridder in the Atlantic. I like the spin, it looks like it might be cutting off, but convection is weak. I see a Subtropical Storm developing next week out of our Carribean disturbance. The water depth does matter but guys come on, think about past storms, a pure tropical storm is not out of the question! It's been said that storms have a mind of there own sometimes.

Hmm... why did I just think Katrina... referring to the surprise, not strength.
Coming out of lurking...

My pressure right now is 29.91 inches, yet I'm in
central Georgia. It is rising and we did have a nasty thunderstorm that went on for about an hour tho.
The 12Z ECMWF appears reasonable, considering the baroclnic enviroment the system is expected to develop.
Given that this front currently runs from Michigan to Western Texas/Mexico Border, it will most certainly impact anything, even marginally, brewing in the GOM and south.

Local forecasters here are calling for morning lows in a range from 25-30 in the mountains of NC/VA. For like 3mornings, there goes my crops.
1009. Drakoen
I like that site Adrian, especially the wind field and the rain imagery. You can tell the system is subtropical.
1010. cg2916
Link to 12Z ECMWF please?
Be back later. The models and observations have spoken and there seems to the consensus that some type of disturbance will exist GOM next week.

Check my 2009 Hurricane Season Outlook.
1012. cg2916
EMCWF looks kind of agressive.

clouds are shearing ene with continueing convective dev. cen fix iam using has been moved to 19.3n/78.0w
1014. IKE
The disturbance is organizing well being under 30 knots, I'm kind of impressed.