Tropical Depression Two forms from Invest 98L

By: Dr. Jeff Masters , 9:33 PM GMT on July 17, 2011

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Tropical Depression Two (TD2) formed from Invest 98L this afternoon. Hurricane Hunters flew into the suspect area and found a surface circulation north of the Bahamas, with maximum sustained winds of 35 mph. They also determined the system had become warm core—a characteristic that must be present in order to declare a tropical cyclone. Satellite imagery continues to show the system is becoming more organized with a stronger circulation. Wind shear is forecast to remain favorable for the system until Tuesday or Wednesday when higher shear will slide in from the north. Sea surface temperatures are warm enough to sustain a tropical storm.


Figure 1. Satellite imagery of Tropical Depression Two in the Atlantic, east of Florida. This graphic will update to the current satellite imagery.


Figure 2. Official 5-day forecast for Tropical Depression Two. This graphic will remain current.

Forecast for TD2

The models are coming into better agreement as TD2 has become more organized. In terms of dynamical forecast models, the HWRF and GFS both forecast TD2 to max out just above tropical storm strenth. HWRF intensifies TD2 to around 47 mph in the next 24 hours, whereas GFS is a bit slower to bring the system up to tropical storm status. Two statistical models, the DSHP (SHIPS model that includes land interaction) and the LGEM (Logistical Growth Equation Model) both intensify TD2 to a moderate tropical storm over the next 2-3 days.

There tends to be a lot of uncertainty involved with tropical cyclones that form under these circumstances, but our forecast remains in line with the National Hurricane Center and the reliable forecast models. TD2 will move slowly to the northeast in weak steering currents over the next few days before eventually becoming an extratropical storm. There is minimal chance that this system will cross over Florida into the Gulf of Mexico. Timing and path depend heavily on how intense the cyclone gets, as Jeff mentioned in his blog earlier today. A weaker storm will tend to stay south, whereas a stronger storm will grow taller in the atmosphere and winds at higher levels will influence it and steer it northeast.

None of the reliable models predict tropical cyclone development over the remainder of the Atlantic through July 23.

Angela

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Quoting FLdewey:
Now that's just creepy


What's creepy is ever since you mentioned it I keep seeing cashews too....
Member Since: August 13, 2007 Posts: 0 Comments: 655
It appears Mission 2 to Bret is in the air.
Member Since: June 29, 2009 Posts: 13 Comments: 5313
Quoting KoritheMan:


Uh, you do realize that's JFV... right?


And you do know what the term Guaricandilla means, right?
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Quoting hunkerdown:
I also don;t see any NE movement commencing in this loop either...


Neither do I. Straight south.
Member Since: June 29, 2009 Posts: 13 Comments: 5313
Quoting Patrap:
I also don;t see any NE movement commencing in this loop either...
Member Since: August 15, 2008 Posts: 0 Comments: 2515
OH WAIT! JULY 27!

that would make it the second storm of the month. That would also make it the THIRD of the year. That would also fit right in with my forecast of 3-5 storms June/July that I posted on my Facebook site. Now would you look at that. I forecasted 3 storms for July.

This is the official quote from my note back in June

July typically is more active than June and historically has seen 2-5 tropical storms in 7 out of the past 15 Hurricane Seasons. 2005 is most notable for spawning the worst July Hurricanes with Dennis and Emily. In fact, Hurricane Dennis is the only Major Hurricane to strike the United States in the month of July over the span of the last 15 years. I believe that this July will not be like 2004 when we didn’t have a storm at all. I just can’t see the current activity in the tropic as slowing down by July. My outlook on July would be 3 Storms, 2 Hurricanes and at least one of them being a Major Hurricane but possibly as many as two.
Member Since: July 22, 2010 Posts: 6 Comments: 752
Quoting ackee:
if bret continue to move south why is the NW Bahamas under a watch and not a warning
maybe his speed of a drift to 2mph?
Member Since: September 18, 2010 Posts: 0 Comments: 5234
The moisture from S. Florida looks like it's being siphoned off right into Bret.
Member Since: August 4, 2006 Posts: 0 Comments: 219
Quoting HurricaneHunterJoe:
Since the models missed on Bret forming, why so much emphasis on the model forecast track? With all the model input and the now closed low system, make them all that much more reliable?


That is a good point.
Member Since: June 29, 2009 Posts: 13 Comments: 5313
SHIPS text from 0z analyzed mid-level dry air at 58%. That, in combination with the diurnal minimum are causing for convective activity to decrease and remain relatively unorganized.

700-500 MB RH 58 56 54 53 50 42 47 47 43 38 35 40 43

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Since the models missed on Bret forming, why so much emphasis on the model forecast track? With all the model input and the now closed low system, make them all that much more reliable?
Member Since: September 18, 2010 Posts: 0 Comments: 5234
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562. JRRP
Quoting Gearsts:
link?

mail
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Quoting wolftribe2009:


You have a link?


12Z at the bottom.
http://raleighwx.americanwx.com/models/ecmwf.html

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560. ackee
if bret continue to move south why is the NW Bahamas under a watch and not a warning
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Quoting AllStar17:
Bret continuing to move south.
further south would be mo better
Member Since: September 18, 2010 Posts: 0 Comments: 5234
If Bret moves S another 24hrs all bets are off for going out to sea and track guidance will have to shift significantly. Farther south he goes the less pull it will feel from the supposed short wave coming across up north.
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Quoting TomTaylor:


Just a quick word to you, Tom. I was maligned recently, and your handle came up, somehow. It wasn't mentioned by me.

For the record, I have no issues with you. I hope you have a nice night. :)

Member Since: Posts: Comments:
520 CybrTeddy "Actually, Atlantis stays at Kennedy Space Center so it would be easier in a sense to have Atlantis land there. Its Endeavour that goes to California."

The name of a Shuttle shouldn't have made a difference. All were built in California, and all were launched from Florida.

As for Patrap pointing out NASA's requirement that they be decommissioned&refurbished in Florida, ain't gonna touch that: 'd torque off too many nice folks. Plus this ain't the place to get into a detailed argument about NASA's management vs NASA's mission.
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Bret continuing to move south.
Member Since: June 29, 2009 Posts: 13 Comments: 5313
Quoting JRRP:

yes
12z euro


You have a link?
Member Since: July 22, 2010 Posts: 6 Comments: 752
Bret has drifted south and slightly west in the last 2 hours imo, also pulling in some moisture from Southern Florida.
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lol does anyone have a funny feeling that we are going to have to spank Cindy for being bad very soon? We could spank her enough and maybe she will veer off over the Atlantic Waters! (Course that is IF it is Cindy. It could be Don or *gulps* Emily)
Member Since: July 22, 2010 Posts: 6 Comments: 752
Quoting BahaHurican:
Lol... agree on the next storm... haven't gone to look @ the actual model runs, but pple keep showing the 240 hr something [ECWMF?] with a huge storm in the GOM and no info on how it got there.... something that big had to have gone through the Car or Bahamas / FL... lo

Been doing that all evening... likely going to check out a Bahama Mama and be a Bahama Breeze for a while... lol



Baha - the strom in the GOMex came from the wave that just left Africa. In the 12Z Euro (and lesser strength in 0Z Euro run).
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Quoting cyclonekid:


Take it with a grain of salt for two reasons.

1. It's the GFS.
2. It's 384 hours out, which is really hard to predict.


True BUT

1: The GFS was showing that 144 hours ago (on Monday)

2: GFS isn't the only model showing it (ECMWF is too)

I hope things change cause that just would not be good.
Member Since: July 22, 2010 Posts: 6 Comments: 752
Quoting GeoffreyWPB:
Looks like the movement to the north/northeast may be starting.


Could be making a clockwise loop, you may be right and why I am seeing a westward component.
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Bret is burying and burying itself deeper and deeper south
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Quoting JRRP:

yes
12z euro
link?
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Quoting GeoffreyWPB:

I don't see a competing circulation in that pic.
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Quoting GeoffreyWPB:


384 hours out!!! I can't remember what I had for breakfast!


I know it's 384 hours out, but it's also the time of year where CV storms start to fire up. I'm not saying it's gonna happen LOL
Member Since: October 8, 2008 Posts: 14 Comments: 4553
541. JRRP
Quoting sunlinepr:
African strong wave... Does models develop it??

yes
12z euro
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I see we have Bret and a very active blog today. Bret doesn't look too impressive in all honesty. Minimal convection coverage, and its not very intense convection, either. The circulation, wind speeds, and convection are obviously there, so don't get me wrong, it is a tropical storm. I'm just saying it is a very weak one at that. Vertical wind shear is very low, and divergence is decent, but it is near the SE periphery of a deep layer ridge which is limiting convection and upper divergence NW of the storm. It's also still along the front, which will inhibit it from becoming too intense and probably wont reach hurricane strength.

Maybe it will, who knows, after all, Bret was kinda of a sneaky storm. A few bloggers, and most of the models, pointed out the potential at some point, but I don't think anyone was really expecting a named system out of this.

Either way, it shouldn't pose a significant threat to land according to the models, which all take it out to the NE.


Over in the WPAC, Ma-On is still heading toward Japan. Quite apparent that the system is not nearly as strong as it was forecasted to be, which is great news for Japan. Looks like it should still slide along the southern coastline, though, and do to its large size and slow movement, it will still be a big concern for Japan.
Member Since: August 24, 2010 Posts: 19 Comments: 4358
Quoting HurricaneHunterJoe:
sure looks like it. i wonder if the mid and LLC will decouple with the LLC going sw/w and the mid circ going ne as forecast by models


Quoting GeoffreyWPB:
Looks like the movement to the north/northeast may be starting.


lots of conflicting reports tonight :)
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Quoting BahaHurican:
wolf, not liking the sound of that. Having a storm headed right at us is not good. Especially since some of our worst here in Nassau have been late July - early Aug major storms...


I live about an hour north of the Panhandle area of the Gulf Coast so I understand. Any storm like that gets into the eastern gulf and I start getting anxious.
Member Since: July 22, 2010 Posts: 6 Comments: 752
Quoting stormpetrol:
IMO Bret is alot more organized than he might appear on Satelite, wouldn't surprise me if he became the first hurricane of the 2011 season.
Based on the sat and dat I'm looking at I concur that Bret's having no problems in the low levels. What happens in the future we watch and wait.
.
.
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Quoting CybrTeddy:
Thunderstorms from SFL are being drawn into Bret's circulation.


Quoting Hurrykane:
Bret pulling in some dry air



hmmmmmm which one is it?
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I'm here, still dont see how it goes off NE out to sea
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Looks like the movement to the north/northeast may be starting.
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Quoting ProgressivePulse:
Seeing a slight westward component last few frames.

Link
sure looks like it. i wonder if the mid and LLC will decouple with the LLC going sw/w and the mid circ going ne as forecast by models
Member Since: September 18, 2010 Posts: 0 Comments: 5234
Bret will be blooming in the morning!
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Quoting KoritheMan:


How is the GFS unreliable?


I'm thinking he means the long range GFS...
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529. ackee
THE central atlantic does have a lot of dry air so any CV system that does try to devlop will have hard time
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Quoting cyclonekid:


Take it with a grain of salt for two reasons.

1. It's the GFS.
2. It's 384 hours out, which is really hard to predict.


How is the GFS unreliable?
Member Since: March 7, 2007 Posts: 587 Comments: 20879
Thunderstorms from SFL are being drawn into Bret's circulation.
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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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