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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Quoting potteryX:
Good Morning.
Post 494, its good to see that this is making "front page" news again. What will the reactions be ???
At 11n 61w, we have had a few gentle showers this morning. Temps yesterday 34c. This is very hot, for an island that is supposed to have its temp. regulated by the balmy sea breezes. Oh well.....


We have been hitting 30 pretty consistently up here also... its nice :)
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Good Morning.
Post 494, its good to see that this is making "front page" news again. What will the reactions be ???
At 11n 61w, we have had a few gentle showers this morning. Temps yesterday 34c. This is very hot, for an island that is supposed to have its temp. regulated by the balmy sea breezes. Oh well.....
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Blog Update
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: 26511
501. IKE
My hottest forecast day is Sunday....inland Florida panhandle...

Sunday
Mostly sunny in the morning then becoming partly cloudy. Northeast winds around 5 mph shifting to the east in the afternoon. Highs 91 to 94.
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Morning All.

Sticky Icky this morning in West Palm. First time I've felt that smack you in the face humidity this year, summer is here my friends.

Humidity: 83%
morning everyone, i'm suprised that the NHC didn't upgrade her to TS...but if i heard right...last night TWC said that if it did get named that it would have been the 1st north storm to ever develope this soon...now of course it's TWC saying this but if it did get named talk about everyone freakin over GW..but hey, who knows maybe this is something we really need to pay attention too for the next few years...since the last 3 have already started earlier each year...something to ponder...
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We are having a heavy rain again in Tampa this morning.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Oh Good Morning everyone.......BBL
Member Since: September 2, 2007 Posts: 178 Comments: 20439
NO Ana.....she started exposing herself about 2am last nite.....i knew there would be no way!
Member Since: September 2, 2007 Posts: 178 Comments: 20439
Oooops...

If TD1 was "Ana"
"she" would be blushing about now:


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This is interesting, there is a new report out that says climate change is killing 300,000 a year.

Link
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Cyclone Aila caused much more trouble than thought.


Cyclone strands millions in India and Bangladesh
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Good morning...
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Back to blob watching- Link
Member Since: July 31, 2006 Posts: 56 Comments: 8112
490. IKE
TD1 is stripping it's clothes....it'll be a naked swirl soon.

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74F this morning, 73F dewpoint
Heavy, moist, icky and sticky.

No Ana yet. That's alright, the TD is a bit north anyhow.
Will the real Ana be a more tropical latitudes girl? A real Ana Banana if you will.

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Baha,

Possibly another indicator of development close to home and more randon development in region 2 (north of 20N, west of 50W).
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485. IKE
From the Houston,TX. morning discussion....

"CLIMATE...
SOME OF OUR AREA COULD USE MORE RAIN. AFTER A RECORD BREAKING WET APRIL
(WETTEST ON RECORD AT IAH AND THIRD WETTEST ON RECORD AT HOU)...WE ARE
ABOUT TO HAVE A RECORD BREAKING DRY MAY. WITH NO RAIN THROUGH THE END
OF THE MONTH...IAH`S MAY TOTAL OF 0.38 INCHES WILL GO DOWN AS THE 7TH
DRIEST ON RECORD AND HOU`S MAY TOTAL OF 0.66 INCHES WILL GO DOWN AS
THE 8TH DRIEST ON RECORD. GLS HAS ONLY RECORDED 0.19 INCHES...BUT THIS
WILL NOT MAKE THE TOP 10 LIST FOR DRIEST MAYS ON RECORD (10TH PLACE
IS 0.12 INCHES)."
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Good morning all. Making my once a day check in STILL ON DIALUP!!!! Argh!!!!

Weather here is definitely into the afternoon thunderstorm pattern, and yesterday I snapped a couple pics w/ my cellphone showing a "passing storm". (If I can get to a faster connection, I'll upload a couple of them.) It never rained in the area from where I took the pics, but I got later reports that mentioned a massive downpour about 3 miles away on the north side of the island. That is one regular component of summer rain in the Bahamas; it is literally possible to stand 100 yards / 90 meters away from a storm cell and watch it go by - without getting wet!

I also notice that there is an area of interest to the east of us. If this develops, even into a depression, it will be the third system in two weeks to form near the Bahamas. Does this mean anything bad this season for the busiest hurricane area in the basin? I suppose it supports the idea of a potentially increased number of storms forming N of 20N and W of 50W, thereby potentially increasing the landfall threat. But we shall see what we shall see.

We have four May days left. I hope you have your hurricane preparations in order! For all the islanders out there, plywood is cheaper now than it will be 36 hours before the potential hurricane strike. . . LOL

Have a great day!
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483. IKE
Looks like Ana will have to wait....

BULLETIN
TROPICAL DEPRESSION ONE ADVISORY NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012009
500 AM AST FRI MAY 29 2009

...DEPRESSION HEADING FOR COLDER WATERS...

AT 500 AM AST...0900 UTC...THE CENTER OF TROPICAL DEPRESSION ONE WAS
LOCATED NEAR LATITUDE 38.9 NORTH...LONGITUDE 66.3 WEST OR ABOUT 260
MILES...420 KM...SOUTHEAST OF NANTUCKET MASSACHUSETTS AND ABOUT 420
MILES...670 KM...SOUTH-SOUTHWEST OF HALIFAX NOVA SCOTIA.

THE DEPRESSION IS MOVING TOWARD THE EAST-NORTHEAST NEAR 15 MPH...24
KM/HR...AND AN INCREASE IN FORWARD SPEED IS EXPECTED DURING THE
NEXT 24 TO 36 HOURS. THE DEPRESSION IS NOT EXPECTED TO THREATEN
ANY LAND AREAS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER
GUSTS. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 24
HOURS. THE DEPRESSION IS EXPECTED TO BECOME EXTRATROPICAL IN THE
NEXT 24 HOURS AS IT MOVES OVER COLDER WATERS AND IS EXPECTED TO
WEAKEN OR DISSIPATE BY SATURDAY.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.

...SUMMARY OF 500 AM AST INFORMATION...
LOCATION...38.9N 66.3W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...EAST-NORTHEAST OR 70 DEGREES AT 15 MPH
MINIMUM CENTRAL PRESSURE...1006 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 AM AST.

$$
FORECASTER BRENNAN/BROWN

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Good Morning

Tropical Depression One/Brazilian Floods Continue
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I'm surprised NHC didn't upgrade TD 1 to Ana. I give it a 30-50% chance of still becoming TS Ana.
Member Since: September 21, 2008 Posts: 9 Comments: 688
i like this td#1
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No Ana makes me :(
if it didn't form over night it isn't forming at all
Member Since: March 29, 2008 Posts: 0 Comments: 2353
advisory is out and there is no Ana so goodnight everyone

also thanks for answering about my earthquake question everyone the reason I asked was because someone I know was saying there was another earthquake in the Atlantic and well that got out of control by a bunch of other people (you know how rumours fly >_> )

So then I had a bunch of people saying that there was a tsunami in the Atlantic and that's when I typed up my question here LOL anyways it turns out the tsunami warning was indeed sent after a region near North Honduras went active but that warning was later retracted.

PS: actually I have some family who lives in Tampa and they felt an earthquake that occurred in the GOM 3 years ago (shook their house knicknacks but I do know that shaking does not occur often near Florida and isn't like those in locations on the ring of fire)
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More like work - tree jumped out in front of this dude's truck - TD1 related??? Earthquake?
At 2AM, what else could it be?

Brazil dam break

Today's POD
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474. Vortfix

Pulling an all nighter here, watching & waiting for that.

LOL
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What happened? I thought the NHC issued their last special advisory on the invest last night. haha. Its a cute little storm
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Lex: If there were Earthquakes near FL, they were so weak as to not be noticable.
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Quoting Hurricane4Lex:
Off topic but has anyone heard of any earthquakes near Florida or Puerto Rico or in the Atlantic region???


Believe it or not, Puerto Rico gets earthquakes almost daily.

The last one I remember around Florida was the strong one (6.0?) west of Tampa in the GOM a year or 3 ago.

In FL we'll mostly feel the ones north of us (carolinas etc) or the caribbean ones.

A week or so ago I found that Alaska had a bunch, the California, then Washington (3) then Pennsylvania (3 or 4 around Harrisburg), Ohio, Texas, Virginia, and New York. All of these within a 2 week period. Surprising?

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Quoting stillwaiting:
might even be Ana in the 2, IMO..


Stillwaiting it will never make it to Ana...its nearly a naked swirl now as the LLC is not under the convection...NO WAY Ana .....
Member Since: September 2, 2007 Posts: 178 Comments: 20439
td 1 has flared up

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might even be Ana in the 2, IMO..
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TD1 is looking like it'll be Ana by the 5am,there's also a area of disturbed weather ENE of the bahamas its in a area that has shear values around only 10kt..this area needs to be watched for development IMO...
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466. Rodek
Quoting Hurricane4Lex:
Off topic but has anyone heard of any earthquakes near Florida or Puerto Rico or in the Atlantic region???



This link should help you.

http://earthquake.usgs.gov/eqcenter/

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465. Rodek
jeffs713,

Thank you for answering my questions.



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Quoting Hurricane4Lex:
Off topic but has anyone heard of any earthquakes near Florida or Puerto Rico or in the Atlantic region???


Yep look like it.....
Member Since: September 2, 2007 Posts: 178 Comments: 20439
I just remembered... on a funktop satellite loop, look for pinks. If you see green, that is a *very* cold cloud top.

Hurricanes aren't as much about altitudes or cloudtop temps, but more organization and a warm core over warm (and deep) SSTs, with little shear.
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Quoting Rodek:
Hurricane force wind speed aside, in order for a storm to strengthen into a hurricane, how cold would the cloud tops need to be? How high do they get?

Hot Towers within a strengthening storm will easily hit 50-60k in altitude. The temps you are generally looking for (going off memory I haven't used in a year) is -60 to -80C. Correct me if I'm wrong on that last part.
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Hey everyone...

Just finished tearing down the Remote Hurricane Weather Station.

I'm configuring the van now for travel to a TC.

It really is a great feeling to see that all my planning and preparation are being rewarded.

Hey P-man...we are being scouted this year...no pressure.
Member Since: August 26, 2006 Posts: 10 Comments: 3620
460. Rodek
Hurricane force wind speed aside, in order for a storm to strengthen into a hurricane, how cold would the cloud tops need to be? How high do they get?
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459. BtnTx
Great to hear you tonight StormJunkie on BarometerBob. What A great project PortLight Is!
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Off topic but has anyone heard of any earthquakes near Florida or Puerto Rico or in the Atlantic region???
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Quoting stillwaiting:
I see no talk tonight of "GOM blobs"...


Good evening everyone......Stillwaitning nothing to talk about if nothing is there.....LOL
Member Since: September 2, 2007 Posts: 178 Comments: 20439
456. beell
Thanks, Oss. Even better!
Member Since: September 11, 2007 Posts: 141 Comments: 16258
I see no talk tonight of "GOM blobs"...
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puny little thing,lol...it won't even wake up the fish....
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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.