Season's first tropical depression forms

By: Dr. Jeff Masters , 3:43 PM GMT on May 28, 2009

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Nature is jumping the gun a bit this year, with the season's first tropical depression forming four days before the official start to hurricane season. The area of disturbed weather (91L) that we've been watching, about 250 miles east-northeast of Cape Hatteras, North Carolina, has developed enough heavy thunderstorm activity and spin to be classified as a tropical depression. QuikSCAT imagery from last night revealed a closed surface circulation, but top winds of only 20 - 25 mph. Satellite estimates (using a cloud pattern recognition method called the "Dvorak" technique) were saying this was a tropical depression this morning, though, so the NHC elected to upgrade the system.

The disturbance is over the relatively warm waters of the Gulf Stream (25°C) and has wind shear of 5 - 10 knots over it, and these conditions are marginally favorable for some slow development to occur until Friday, when the system will likely move over waters too cold to support intensification. TD One is not a threat to any land areas. I give the storm a 60% chance of becoming Tropical Storm Ana.


Figure 1. Latest satellite image of TD One.

Is the formation of TD One a harbinger of an active hurricane season?
Probably not. Early season storms occurring near the U.S. coast have not been shown to be correlated with an active main portion of hurricane season during August - October. However, the situation is different if we start getting June and July storms in the deep tropics between Africa and the Lesser Antilles Islands. This was the case last year, when the formation of Hurricane Bertha in the deep tropics in July presaged an active 2008 hurricane season. According to the Hurricane FAQ, "as shown in (Goldenberg 2000), if one looks only at the June-July Atlantic tropical storms and hurricanes occurring south of 22°N and east of 77°W (the eastern portion of the Main Development Region [MDR] for Atlantic hurricanes), there is a strong association with activity for the remainder of the year. According to the data from 1944-1999, total overall Atlantic activity for years that had a tropical storm or hurricane form in this region during June and July have been at least average and often times above average. So it could be said that a June/July storm in this region is pretty much a "sufficient" condition for a year to produce at least average activity."

Portlight.org offering relief to Florida flood victims
Tropical disturbance 90L dropped as much as two feet of rain over Northeastern Florida last week, causing severe flooding. In Volusia County, at least 1500 homes were damaged by the flooding, and many of these were in low-income housing projects where the residents did not have flood insurance. Portlight Strategies, Inc., is now working to assist in this area by providing durable medical equipment to the disabled, elderly, or injured that have lost equipment due to the flooding. Equipment will also be provided to local shelters and other organizations working with flood victims. To help out, visit the Portlight disaster relief blog..


Figure 2. Rainfall amounts over Florida for the two weeks ending on May 27, 2009. Images credit: NOAA.

Jeff Masters

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Reflector site for those at work, which now also includes Weather456, daily updates


TD 1

AOI #2
Member Since: October 1, 2007 Posts: 81 Comments: 26516
Quoting presslord:
Do y'all remember 'Stoopid' from last year? His response to Hebert Boxes was 'The Stoopid Circle'...he drew a huge circle encompassing all of the US East and Gulf coasts, Central America, and the Carribean...it was hilarious...

Someone else something funny to say regarding the cat box and the Hebert boxes...cannot remember what it was!
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Quoting Weather456:
Good Afternoon....

Tropical Depression set records


I looked.. umm what record?
Member Since: October 1, 2007 Posts: 81 Comments: 26516
I just complete a Tropical Update if anyone would like to view....

TampaSpins Tropical Update Link
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Its a Tropical Storm - it has to be.
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Quoting Barefootontherocks:
Good afternoon. Interesting watching the GOM today.



Do you mean Stoopid1? I don't think anyone's ever posted here under the handle just plain "stoopid."


Ya that's them.
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Good afternoon. Interesting watching the GOM today.

Quoting presslord:
Do y'all remember 'Stoopid' from last year? His response to Hebert Boxes was 'The Stoopid Circle'...he drew a huge circle encompassing all of the US East and Gulf coasts, Central America, and the Carribean...it was hilarious...


Do you mean Stoopid1? I don't think anyone's ever posted here under the handle just plain "stoopid." lol
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Good Afternoon....

Tropical Depression 1 sets records
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Member Since: October 1, 2007 Posts: 81 Comments: 26516
Quoting CaneWarning:


It certainly does look like smoke doesn't it? I don't know of any fires out there though.

Yeah theres still quite a few fires burning in SRQ county, pretty normal for this time of year. Nice squall line offshore might put it out, or fuel it with wind, clouds are getting darker and darker here...
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Quoting CaneWarning:
It's cool to see the graphics the NHC is using this year... No skinny black line.


You can turn it on or off. They did it last year too.
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Member Since: October 1, 2007 Posts: 81 Comments: 26516
It's cool to see the graphics the NHC is using this year... No skinny black line.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Funny how fast everything changes. We all went to bed thinking 91L was dead, the next day we have a tropical depression.
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no threat to land
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back to work for me back at break time at 315 later all
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Quoting presslord:
Do y'all remember 'Stoopid' from last year? His response to Hebert Boxes was 'The Stoopid Circle'...he drew a huge circle encompassing all of the US East and Gulf coasts, Central America, and the Carribean...it was hilarious...


I guess that's why his name was stoopid. LOL
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70. stillwaiting 4:54 PM GMT on May 28, 2009
Is that area east of the interstate a fire or???

It is a prescribed burn out at the Pinelands
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Do y'all remember 'Stoopid' from last year? His response to Hebert Boxes was 'The Stoopid Circle'...he drew a huge circle encompassing all of the US East and Gulf coasts, Central America, and the Carribean...it was hilarious...
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Quoting Levi32:


The same thing lol. For example, the furthest west yellow line on the edge of the map over Mexico is a trough.

As for the other line from NW Florida stretching SW, I'm not sure, could be an outflow boundary, but I'm not sure.


That would for sure represent the pre-frontal trough in front of the CF.
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Quoting beell:


Sounds good to me, thanks.
It does look like outflow anyway-imho.


Well it's not even a squall-line anymore because its dead, but you know the surface maps are only updated every 6 hours. The SSD loops do not always have accurate surface overlays either.
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Quoting Levi32:


The same thing lol. For example, the furthest west yellow line on the edge of the map over Mexico is a trough.


Sounds good to me, thanks.
It does look like outflow anyway-imho.
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Quoting beell:


That would make sense. What do they use to mark a trough?


The same thing lol. For example, the furthest west yellow line on the edge of the map over Mexico is a trough.

As for the other line from NW Florida stretching SW, I'm not sure, could be an outflow boundary, but I'm not sure.
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Quoting Levi32:


That dashed line represents a squall line, not a trough.


That would make sense. What do they use to mark a trough?

Also one painted in from the panhandle of FL to the SW and another stretching S from the cold front over the coast of eastern MX.
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no disrespect intended towards ya stormw we all are here to learn even those that already know
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Quoting beell:


Howdy, Skye,

SSD GOM loop has a surface trough added over this feature. Looks like plain old outflow from collapsing t-storms. Y/N?

(select "Fronts" checkbox)
Link



That dashed line represents a squall line, not a trough.
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Quoting Skyepony:
Marco~ it's not feeding on that gulf loop eddy anymore. In comment 1 notice how it's blowing up as the prefrontal boundry touches Cuba. Just give it a little heat.


Howdy, Skye,

SSD GOM loop has a surface trough added over this feature. Looks like plain old outflow from collapsing t-storms. Y/N?

(select "Fronts" checkbox)
Link

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the line coming of the GOM seems to be intensifing..
Member Since: October 5, 2007 Posts: 20 Comments: 4970
Quoting stillwaiting:
Is that area east of the interstate a fire or???


It certainly does look like smoke doesn't it? I don't know of any fires out there though.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Is that area east of the interstate a fire or???
Member Since: October 5, 2007 Posts: 20 Comments: 4970
Quoting StormW:


Just try to keep things short and simple when I can.


Yeah, things will be complicated soon enough.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting AggiemetinKaty:

While no one can say for sure what is going to happen, we can look at indicators and predict what will probably happen. Such indicators as lower SST's, neutral-El Nino conditions, and likely higher shear values in the MDR all indicate that this year will be an average to slightly below average hurricane season. With that said, all it takes is one!


LOL and does that really matter? Look at all TD1 had going against it and yet it formed. I certainly wouldn't bet against an average to above average season this year, below average seasons are a rarity these days!
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If this had been later in the year,I'd be a little concerned here in New England.
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RE: forecast accuracy.


I have searched high and low and cannot find the term, Surecast, anywhere in this site's info, so I guess we have to continue to use forecast :)

Terms used by meteorologists
Member Since: June 12, 2005 Posts: 6 Comments: 8188
Quoting 7544:
well at least we can say the first texas blob did make it to fla in less than 24 hours when we first saw it yestrday and last night will the second texas blob do the same and maybe hold its own the gfs run just out says yes


Yes, Florida may be in for more rain again.
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I am trying a will a thunderstorm my way so I can see my new weather station in action. Haven't seen much action since I got it up and running on Saturday. I think the highlight has been a 13mph gust. LOL. Can't really complain though, weather has been beautiful here since 90L exited.
Member Since: May 15, 2009 Posts: 0 Comments: 33
Quoting AussieStorm:
Goodnight all.... stay safe


Goodnight.
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60. 7544
well at least we can say the first texas blob did make it to fla in less than 24 hours when we first saw it yestrday and last night will the second texas blob do the same and maybe hold its own the gfs run just out says yes
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Skyee, you are right. Good point.
Member Since: May 15, 2009 Posts: 0 Comments: 33
Goodnight all.... stay safe
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Quoting BrandiQ:


Great more rain. I wouldnt mind just one day of full sunshine. Im tired of the flooding!


Maybe Cantori will be able to dock his rowboat right outside the hotel if we get a storm this year.
55. Skyepony (Mod)
Marco~ it's not feeding on that gulf loop eddy anymore. In comment 1 notice how it's blowing up as the prefrontal boundry touches Cuba. Just give it a little heat.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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