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 theFatherofNature:
Anyone know any good schools to go to to study atmospheric sciences(mainly hurricanes).

I'd like to know that too, I know Penn State has an online meteorology course, I'm taking it online over the summer. I think Florida has good meteorology colleges too but I think I'm assuming that because it get's hit by the most hurricanes. Hope I was helpful, Goodnight.
Member Since: March 29, 2008 Posts: 0 Comments: 2370
Doesn't look like we'll have Ana.
Member Since: November 24, 2005 Posts: 635 Comments: 26601
Wind shear has increased over the system to 10-20knots.
Member Since: October 28, 2006 Posts: 57 Comments: 30213
351. IKE
1:09 AM GMT on May 29, 2009
I think TD1 is heading for a graveyard....soon.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
350. Drakoen
1:08 AM GMT on May 29, 2009
01L looking pretty ragged.
Member Since: October 28, 2006 Posts: 57 Comments: 30213
349. IKE
1:08 AM GMT on May 29, 2009
Quoting Ossqss:


Ok, I will bite as usual, POD? I think I know its not the music group and may be prediction related, but, don't know for sure.

BTW,Skyepony, been doin some research on Sat- microwave cumulative impact on atmosphere. Not much out there, but very interesting :)


Plan-Of-Day....for Aircraft Reconnaissance Plan of the Day
Member Since: June 9, 2005 Posts: 23 Comments: 37858
348. Levi32
1:08 AM GMT on May 29, 2009
Looks like the whole convective mass is about to slide right off the plate. Wind shear is about to expose the LLC on the NW side, and the mid-level feature with associated thunderstorms will move off towards the east with the upper-level flow, and the LLC will continue NE in the low-level flow.

Visible Loop
Member Since: November 24, 2005 Posts: 635 Comments: 26601
347. CycloneOz
1:06 AM GMT on May 29, 2009
Quoting Skyepony:
OZ~ Frances was like 3 days.. Hope your testing that thing long enough... Plans for more than one feed at a time? We do get to watch you live too?



72-hours won't be possible with the station.

I anticipate a maximum of 50-hours battery life, maybe more if lucky. But you're right...a very slow moving system could throw a wrench in the deal.

More than one feed would require more than one remote station (sans weather station). It would also require more than one subscription to Abacast.com (big ticket item.)

Any additional feeds would require additional team members in charge of additional remote stations. A single remote station costs $2,000.

Finally, yes...you'll see me live from time to time in the shot on the streets below (station will be placed well above street-level.) I may have company! P...you out there boss! :)
Member Since: August 26, 2006 Posts: 10 Comments: 3622
346. Drakoen
1:05 AM GMT on May 29, 2009
CI# /Pressure/ Vmax
2.4 /1005.8mb/ 34.0kt


Final T# Adj T# Raw T#
(3hr avg)
2.4 2.9 3.2
Member Since: October 28, 2006 Posts: 57 Comments: 30213
345. Ossqss
1:00 AM GMT on May 29, 2009
Quoting Skyepony:
I guess there will be no POD today.


Ok, I will bite as usual, POD? I think I know its not the music group and may be prediction related, but, don't know for sure.

BTW,Skyepony, been doin some research on Sat- microwave cumulative impact on atmosphere. Not much out there, but very interesting :)
Member Since: June 12, 2005 Posts: 6 Comments: 8186
344. Skyepony (Mod)
12:58 AM GMT on May 29, 2009
Oss~ Quikscat should sail over in the hour. I haven't been slumming buoys today.

OZ~ Frances was like 3 days.. Hope your testing that thing long enough... Plans for more than one feed at a time? We do get to watch you live too?

Member Since: August 10, 2005 Posts: 162 Comments: 37822
343. GeoffreyWPB
12:58 AM GMT on May 29, 2009
https://my.sfwmd.gov/sfwmd/common/images/weather/plots/storm_91.gif
Member Since: September 10, 2007 Posts: 0 Comments: 11108
342. CycloneOz
12:53 AM GMT on May 29, 2009
Remote Hurricane Station shut-down imminent!

The next time it runs, it will be go-time.
Member Since: August 26, 2006 Posts: 10 Comments: 3622
341. Skyepony (Mod)
12:51 AM GMT on May 29, 2009
I guess there will be no POD today.
Member Since: August 10, 2005 Posts: 162 Comments: 37822
340. Patrap
12:47 AM GMT on May 29, 2009
Member Since: July 3, 2005 Posts: 423 Comments: 127814
339. charlesimages
12:46 AM GMT on May 29, 2009
Quoting GeoffreyWPB:
tick tick tick..will we have Ana in May or not???

I'm going to say no.
Member Since: May 25, 2006 Posts: 347 Comments: 29278
338. Ossqss
12:46 AM GMT on May 29, 2009
Just jumpin in for a sec. I have been told our TD item has 5mph winds on the west side. Is that true?
Member Since: June 12, 2005 Posts: 6 Comments: 8186
337. StormJunkie
12:40 AM GMT on May 29, 2009
335. I doubt it...Looks like it is on the way to the bone yard now...
Member Since: August 17, 2005 Posts: 26 Comments: 16361
336. WPBHurricane05
12:40 AM GMT on May 29, 2009
The Central Pacific Hurricane Center changed its lead time for Hurricane/Tropical Storm watches and warnings. Link

A watch is now 48 hours.
A warning is now 36 hours.
Member Since: July 31, 2006 Posts: 56 Comments: 8112
335. GeoffreyWPB
12:39 AM GMT on May 29, 2009
tick tick tick..will we have Ana in May or not???

Member Since: September 10, 2007 Posts: 0 Comments: 11108
334. theFatherofNature
12:31 AM GMT on May 29, 2009
Thank you all for the lists of colleges. I'm trying to go somewhere in south florida
333. Patrap
12:26 AM GMT on May 29, 2009
LOL..

LSU can be lost in the Fray,cept during football season.

ESL By LSU Hurricane Page

Member Since: July 3, 2005 Posts: 423 Comments: 127814
332. StormJunkie
12:25 AM GMT on May 29, 2009
Thanks Pat, Can't believe I forgot LSU...
Member Since: August 17, 2005 Posts: 26 Comments: 16361
331. weatherbro
12:24 AM GMT on May 29, 2009
Looks like Central Florida is gonna get some relief out of this late season front.:) Which'll dissipate across the southern tip of the peninsula or The Bahama's/Cuba.

The main benefits will only be from Lake Okeechobee northward on Sunday. Looks like we won't see the storms return until next Wednesday/Thursday in what may be another late season cool front.
Member Since: May 26, 2007 Posts: 47 Comments: 1286
330. Patrap
12:24 AM GMT on May 29, 2009
LSU Has a complete atmospheric Studies curriculum as well.


ESL by LSU
Member Since: July 3, 2005 Posts: 423 Comments: 127814
329. ChrisDcane
12:20 AM GMT on May 29, 2009
soooooooooo we do have a low in the gulf. :) :/ :(:!
328. CycloneOz
12:19 AM GMT on May 29, 2009
Quoting GeoffreyWPB:
Oz..what will be different from your coverage of land falling storms than that of local media?


Broadcast media will not stick a camera and weather station in the storm and without interruption broadcast a storm in real-time.

Once we set up the remote station, you will have a window on the storm...uninterrupted and without human noise...(unless the microphone picks up sounds regular people are making in the hurricane....like screaming for help.)

Hour upon hour will pass, streaming at near frame capacity of 29.97 frames per second...all the while, the weather station data will provide you with all things data...including the most important thing...wind speed.

Sure...you could turn on your TV and watch talking heads wearing cheap blue slickers and swimming goggles talk about the impending doom of the storm as they're tossed about by 50 mph outer band winds right as they cut to commercial...or, you could tune into the XtremeHurricanes.com website manned by wunderground.com members and see for yourself how bad it is....minute to minute...hour by hour.
Member Since: August 26, 2006 Posts: 10 Comments: 3622
327. Orcasystems
12:14 AM GMT on May 29, 2009
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
326. GeoffreyWPB
12:10 AM GMT on May 29, 2009
Oz..what will be different from your coverage of land falling storms than that of local media?
Member Since: September 10, 2007 Posts: 0 Comments: 11108
325. StormJunkie
12:07 AM GMT on May 29, 2009
Eric Blake from the NHC is on the Barometer Bob show tonight.

They are discussing the forecast process.
Member Since: August 17, 2005 Posts: 26 Comments: 16361
324. CycloneOz
12:03 AM GMT on May 29, 2009
All testing of the remote hurricane weather station / live webcam is now completed! It will now be disassembled and configured on the CycloneOz Hurricane Van for deployment.

Right now, it's still running with about 1-hour left before disassembly.

It has run now for over 36 consecutive hours...that is two complete day-time periods.

Even a slow moving TC will not escape capture!

Mahvelous!

When we deploy the system, I hope you all are satisfied with the window the XtremeHurricanes.com team will provide you upon a landfalling hurricane.
Member Since: August 26, 2006 Posts: 10 Comments: 3622
323. GeoffreyWPB
11:59 PM GMT on May 28, 2009

Atlantic Tropical Weather Discussion
--------------------------------------------------------------------------------
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU MAY 28 2009

...SPECIAL FEATURE...
TROPICAL DEPRESSION ONE IS CENTERED NEAR 37.7N 69.4W AT 28/2100
UTC OR ABOUT 265 NM SOUTH-SOUTHEAST OF PROVIDENCE RHODE ISLAND
AND ABOUT 490 NM SOUTHWEST OF HALIFAX NOVA SCOTIA MOVING NE AT
14 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM
SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SCATTERED
MODERATE CONVECTION IS WITHIN 90 NM OF THE CENTER IN THE E
SEMICIRCLE. PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. THE
DEPRESSION COULD BECOME A TROPICAL STORM TONIGHT OR FRIDAY...BUT
THEN IS EXPECTED TO WEAKEN OR DISSIPATE OVER COLDER WATERS BY
SATURDAY.
Member Since: September 10, 2007 Posts: 0 Comments: 11108
322. hurristat
11:56 PM GMT on May 28, 2009
Quoting Levi32:


They only issue intermediate advisories when land is threatened.


Thank you!
Member Since: October 15, 2008 Posts: 11 Comments: 2312
321. hurricanemaniac123
11:55 PM GMT on May 28, 2009
Quoting hurristat:
What is the chance that they will do an 8:00 update? At this point, it seems low, but I was wondering if they were going to issue one.


We'll just have to wait 'till 11pm. I'm guessing we will have TS Ana by then or maybe 5am tommorow.
Member Since: September 21, 2008 Posts: 9 Comments: 688
320. hurristat
11:55 PM GMT on May 28, 2009
Quoting jeffs713:


FSU would be my first suggestion, followed by Penn St, and CSU.


Would Cornell or MIT be good?
Member Since: October 15, 2008 Posts: 11 Comments: 2312
319. Levi32
11:55 PM GMT on May 28, 2009
Quoting hurristat:
What is the chance that they will do an 8:00 update? At this point, it seems low, but I was wondering if they were going to issue one.


They only issue intermediate advisories when land is threatened.
Member Since: November 24, 2005 Posts: 635 Comments: 26601
318. hurristat
11:54 PM GMT on May 28, 2009
What is the chance that they will do an 8:00 update? At this point, it seems low, but I was wondering if they were going to issue one.
Member Since: October 15, 2008 Posts: 11 Comments: 2312
317. Levi32
11:53 PM GMT on May 28, 2009
TD 1's center is starting to migrate out from under the center, and is now on the northwest side of the convection. Cloud tops are also warming. I think TD 1 has passed its peak.

Member Since: November 24, 2005 Posts: 635 Comments: 26601
316. AussieStorm
11:53 PM GMT on May 28, 2009
Enormous crater swallows car in Bellevue Hill, Sydney


Article from: The Daily Telegraph

By Amy Dale and David Barret

May 29, 2009 09:00am

RESIDENTS and motorists were stunned to discover a 25- metre crater that caused a landslide and swallowed two cars in Bellevue Hill in Sydney's east as they made their way to work this morning.
Link
Member Since: September 30, 2007 Posts: 9 Comments: 15935
315. DDR
11:51 PM GMT on May 28, 2009
Quoting Weather456:
DDR,

the activity across Africa is being caused by a variety of factors, but ITCZ instability and AEJ seems to the main caused. There does not seem to be wave-like feature at the moment but because the convection is being generated along the AEJ, I would not rule out the formation of one. The is a good amound of vorticity along West Africa but it maybe associated with a secondary circulation. Upper air observastions not showing much cyclonic turning, but any bulge in the low level moisture field over the Atlantic ocean over the next few days would signify one has/had emerge/emerged.

Thanks
Quoting Weather456:


I'm looking into the area you asked but it does not look so


I see some nice showers to your east,the wind looks light in that general area.
Member Since: April 27, 2007 Posts: 14 Comments: 1699
314. WPBHurricane05
11:50 PM GMT on May 28, 2009
The 18UTC run of the GFS has my June tropical disturbance headed for Florida. Link
Member Since: July 31, 2006 Posts: 56 Comments: 8112
313. presslord
11:44 PM GMT on May 28, 2009
yup...it'd probably be a good idea to mention Michigan on this particular website....
Member Since: August 13, 2007 Posts: 0 Comments: 10484
312. all4hurricanes
11:43 PM GMT on May 28, 2009
Almost 50 past the hour we'll see if the weather channel has a new update.
Member Since: March 29, 2008 Posts: 0 Comments: 2370
311. StormJunkie
11:41 PM GMT on May 28, 2009
Quoting jeffs713:


FSU would be my first suggestion, followed by Penn St, and CSU.


Can't leave out University of Wisconsin - Madison, or Universtiy of Michigan...

Evening all
Member Since: August 17, 2005 Posts: 26 Comments: 16361
310. AussieStorm
11:37 PM GMT on May 28, 2009
Five dead, 13 wounded in earthquake in Honduras

Article from: Agence France-Presse

May 29, 2009


Powerful ... one of the lanes of the La Democracia bridge over the Ulua river had its central section collapse/ AFP

* 7.1-magnitude earthquake rocks Honduras
* Five dead, 13 injured
* Panicked residents forced onto streets

FIVE people died and 13 were injured when a powerful 7.1-magnitude earthquake rocked Honduras last night.

"We have a first report of five dead and 13 wounded," said Ana Rivera, spokeswoman of the Permanent Emergency Commission.

The quake - which sent panicked residents onto the streets in the middle of the night - damaged two bridges, 50 homes, 10 schools, two public buildings, two hotels, a factory and a church, according to first reports, Ms Rivera said.

A total of 17 aftershocks, all above magnitude four, had been recorded, she added.

The quake struck at 2.24am (6.24pm yesterday AEST) off the northern coast of Honduras, near the tourist resort of the Islas de la Bahia in the Caribbean, according to the US Geological Survey (USGS).

The main tremor deep below the Caribbean coast led to a 90-minute tsunami alert for Honduras and neighbouring Guatemala and Belize, which was later withdrawn.
Member Since: September 30, 2007 Posts: 9 Comments: 15935
309. WPBHurricane05
11:37 PM GMT on May 28, 2009
ADT estimates have 01L at 34 knots (39.1 mph)...barely a tropical storm.

If there is a nice burst of convection during the next hour or so we will probably have Ana at the 11pm advisory.
Member Since: July 31, 2006 Posts: 56 Comments: 8112
308. jeffs713
11:33 PM GMT on May 28, 2009
Quoting theFatherofNature:
Anyone know any good schools to go to to study atmospheric sciences(mainly hurricanes).


FSU would be my first suggestion, followed by Penn St, and CSU.
Member Since: August 3, 2008 Posts: 16 Comments: 5880
307. nrtiwlnvragn
11:25 PM GMT on May 28, 2009
Quoting PELLSPROG:
Is there such a thing as a recurvature or is it just a curve without a RE ? I am always confused when I hear that a storm is recurving.


recurvature—The change in direction of tropical cyclone movement from westward and poleward to eastward and poleward, under the influence of midlatitude westerlies.
Such recurvature of the path frequently occurs as storms move into midlatitudes and is a major concern in tropical cyclone forecasting.

Glossary of Meteorology
Member Since: September 23, 2005 Posts: 14 Comments: 11080
306. HaboobsRsweet
11:24 PM GMT on May 28, 2009
Quoting theFatherofNature:
Anyone know any good schools to go to to study atmospheric sciences(mainly hurricanes).

The best schools IMO are Penn State, Oklahoma, FSU, Colorado St. and NC State to name a few. For hurricanes, probably FSU and maybe Florida Tech since it is in Melbourne.
Member Since: May 20, 2009 Posts: 0 Comments: 1640
305. HaboobsRsweet
11:22 PM GMT on May 28, 2009
We had waterspouts reported this morning right ont he edge of the Gulf in Biloxi, MS today. The observer even augmented the obs and added them in. That blob as you call it was a beast this morning.
Member Since: May 20, 2009 Posts: 0 Comments: 1640
304. PELLSPROG
11:20 PM GMT on May 28, 2009
Is there such a thing as a recurvature or is it just a curve without a RE ? I am always confused when I hear that a storm is recurving.
Member Since: September 4, 2008 Posts: 0 Comments: 142

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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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