Still watching for a potential early-season Atlantic subtropical storm

By: Dr. Jeff Masters , 7:10 PM GMT on May 16, 2009

Share this Blog
1
+

The latest 00Z and 12Z runs of the GFS, UKMET, NOGAPS, and ECMWF global dynamical computer models continue to indicate the possibility of an early season subtropical storm forming in the Gulf of Mexico 3 - 7 days from now. A modest area of low shear air is expected to open up between the polar jet stream to the north and the subtropical jet stream to the south, between Cuba and the northern Gulf of Mexico. The models have not been consistent with the timing or the size of this low shear area, and I wouldn't be surprised to see them back off again from this forecast with Sunday's set of runs. Nevertheless, I'll call once again for a 10% chance of development of a subtropical depression in the eastern Gulf of Mexico, 4 - 7 days from now. There isn't much of a disturbance at present to look at--there are some scattered showers between Cuba and Jamaica, but they are under a hefty 30 knots of wind shear. These showers should gradually increase in intensity and areal coverage over the next two days, and phase space diagrams from Florida State University indicate that an extratropical low may form near the western tip of Cuba 2 - 3 days from now. The storm may then gradually transition to a subtropical or tropical system later in the week, if the shear is low enough. Even if the shear is high and the storm remains extratropical, it could be a substantial rain-maker where it comes ashore. The models target the northern Gulf Coast between Louisiana and the Florida Panhandle as the most likely landfall location, but it is too early to place any confidence in this track.

There is also about a 10% chance a subtropical storm may form 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 a subtropical storm. 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 Sunday.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 387 - 337

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25Blog Index

Quoting Weather456:
While convection has gotten noticeable alot more spatial and stronger south of Cuba it is not self sustaining yet. It is being generated by cyclonic mid-upper level winds. But this seems to be the beginning.


You have a good eye....Time for this old man to "retire" for the evening...Yall have a nice one and happy hunting.....WW
Member Since: Posts: Comments:
Quoting KEEPEROFTHEGATE:
i think it would be better if there was a IQ requirement and spelling test


An IQ test...I love it.
Member Since: Posts: Comments:
Member Since: July 15, 2006 Posts: 169 Comments: 53307
Well looks like this is what the models are developing.

Member Since: Posts: Comments:
Quoting WeatherStudent:
WOW, WU should have some kind or some sort of age ristriction by-law before just anyone can gain access in to this blog and chat away with us.


Excuse Me?
Member Since: September 7, 2008 Posts: 17 Comments: 1604
Quoting WeatherStudent:
WOW, WU should have some kind or some sort of age ristriction by-law before just anyone can gain access in to this blog and chat away with us.
i think it would be better if there was a IQ requirement and spelling test
Member Since: July 15, 2006 Posts: 169 Comments: 53307
I wonder how the 2009 hurricane season will react to the Obama administration?
Member Since: Posts: Comments:
While convection has gotten noticeable alot more spatial and stronger south of Cuba it is not self sustaining yet. It is being generated by cyclonic mid-upper level winds. But this seems to be the beginning.
Member Since: Posts: Comments:
Quoting Ossqss:


HBD wannabe,

I have socks older than most of you :)


Thanks...Family went out of town for the weekend so I celebrated with the TV, some Sushi, and several Sam Adams.....It was a great Birthday......Lol
Member Since: Posts: Comments:
Drake?
Member Since: Posts: Comments:
Quoting WeatherStudent:
WOW, WU should have some kind or some sort of age ristriction by-law before just anyone can gain access in to this blog and chat away with us.


Look whos talking.
Member Since: Posts: Comments:
Quoting weathermanwannabe:
Nothing to hide here....Turned 48 yesterday...Now back to the weather....Lol


HBD wannabe,

I have socks older than most of you :)
Member Since: Posts: Comments:


925 mb vort
Member Since: July 15, 2006 Posts: 169 Comments: 53307
I'll be 15 in July.
Member Since: September 7, 2008 Posts: 17 Comments: 1604

GOM IR Loop
Member Since: Posts: Comments:
How old is StormW?
Member Since: Posts: Comments:
Quoting Patrap:
Im 343 in Dog Years.

Do the Math..LOL


Your 49
Member Since: September 7, 2008 Posts: 17 Comments: 1604
Nothing to hide here....Turned 48 yesterday...Now back to the weather....Lol
Member Since: Posts: Comments:
Quoting hurricaneseason2006:
W456,

I want to email WU about making your blog and StormW's blog a featured blog after someone mentioned it this morning. Your blog will be indispensable this season.

Second on that.
Member Since: Posts: Comments:
Quoting NorthxCakalaky:
Weather456 How old are you?


21 in July
Member Since: Posts: Comments:


here is another sst map
Member Since: July 15, 2006 Posts: 169 Comments: 53307
Im 343 in Dog Years.

Do the Math..LOL
Member Since: Posts: Comments:
Quoting Drakoen:


How old are you? I know no respectable adult would have the audacity to ask that.



18 sorry..
Member Since: Posts: Comments:
GOM 60 Hour Water Surface Temperature Forecast
Member Since: Posts: Comments:
Quoting NorthxCakalaky:
Weather456 How old are you?


How old are you? I know no respectable adult would have the audacity to ask that.
Member Since: Posts: Comments:
GOM 60 Hour Forecast (using WAM)
Member Since: Posts: Comments:
Member Since: July 15, 2006 Posts: 169 Comments: 53307
Weather456 How old are you?
Member Since: Posts: Comments:
We'll take what we can Beell.
Member Since: Posts: Comments:
SSTs (F)
Member Since: Posts: Comments:
Moisture should start to increase over the Caribbean over the next 24-36hrs. The moisture over the next few days will coincide with the upward phase of the MJO.
Member Since: Posts: Comments:
Plenty of moisture, fronts, and warmth around the Gulf and Northern Caribbean (for an early season storm)...Seems to me that shear will be the deciding factor over the next several days...
Member Since: Posts: Comments:
Just looked at my 7 day forecast!! Rain chances are looking awesome! YIPEE!!!!

Sun 60%

Mon 70%

Tue 60%

Wed 70%

Thur 60%

Fri 50%

Sat 40%
Member Since: Posts: Comments:
Member Since: July 15, 2006 Posts: 169 Comments: 53307
343. beell
Highest rainfall well off to the NE of a surface low. With some interaction with the cold front. As one might expect from a non-tropical system-or one in transition.

Valid 12Z Tuesday through 12Z Thursday



Link
Member Since: Posts: Comments:
GOM Obs - showing pressure tendencies


Member Since: Posts: Comments:
Quoting Drakoen:

Closer to a tropical cyclone than 2 hours ago.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting cg2916:

An animated one?


Choose the time you wish to view whether its 72,84,or 96 for stills.If you wish to view animated version hit LOOP on the right hand side.Scroll down to(Previous 12-hr Precipitation Rate). NOGAPS
Member Since: Posts: Comments:
Quoting IKE:
At 132 hours it's still south of Mobile. This could be a major flooding event for some.
from a dust bowl to a mud bowl
Member Since: July 15, 2006 Posts: 169 Comments: 53307
:(
Member Since: Posts: Comments:

Viewing: 387 - 337

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.