Disturbance 90L close to tropical depression strength; TD 2 may rise again

By: Dr. Jeff Masters , 2:02 PM GMT on August 14, 2009

Share this Blog
5
+

A strong tropical wave (90L), with a large circulation and a moderate amount of heavy thunderstorm activity, is a few hundred miles southwest of the Cape Verdes Islands, off the coast of Africa. This morning's QuikSCAT pass shows that 90L has a large circulation, but this circulation is not yet well-formed, as it is elongated along an east-west axis. Satellite imagery from the European METEOSAT satellite show that the heavy thunderstorms associated with 90L are gradually becoming better organized, with some spiral banding evident on the south side of the storm. Satellite intensity estimates from NOAA already put 90L at tropical depression strength with 30 mph winds, but the storm does not yet have a well enough formed circulation to be classified as a depression. Water vapor imagery shows that since 90L is forming several hundred miles south of the dry air of the Saharan Air Layer (SAL), the storm should not be affected by dry air and dust as much as Tropical Depression Two was. However, there is some dry air from the SAL being sucked into the circulation of 90L, and this is retarding its development.

Wind shear is moderate, about 10 - 15 knots, but is forecast to fall to the low range, 5 - 10 knots, later today. Shear is then forecast to remain low for the next five days. Sea Surface Temperatures are about 28°C, and will remain in the 27 - 28°C range the next five days. The combination of low wind shear and sufficiently warm SSTs should allow 90L to develop into a tropical depression by Saturday, and potentially reach hurricane strength by Wednesday. Most of our reliable models strengthen 90L into a hurricane by Wednesday, when the storm is expected to be near the northern Lesser Antilles Islands. One important outlier is the ECMWF model, which has 90L passing to the north of the islands, and eventually recurving out to sea east of Bermuda. The ECMWF was by far the most reliable model for forecasting hurricane tracks last year. However, all of our models are pretty unreliable going out 5 days in advance for systems that have yet to reach tropical depression strength. Once 90L becomes a tropical depression and develops a well-formed circulation, the models will have a better handle on forecasting where it will go.


Figure 1. The remnants of Tropical Depression Two (left side of image) and tropical wave 90L (right side of image).

Tropical Depression Two may come back
Tropical Depression Two died yesterday, but may rise again. Satellite loops of the remnants of the storm show that heavy thunderstorms are again attempting a comeback near the axis of what is now a tropical wave. However, dry air continues to interfere with the development of the thunderstorm activity, and moderately high wind shear of 15 - 20 knots is also inhibiting the process. Wind shear over the remnants of TD 2 is expected to remain in the moderate range, 10 - 20 knots, over the next four days. Sea Surface Temperatures (SSTs) are 27°C, but will warm to 28°C two days from now. There is plenty of dry, stable air from the Saharan Air Layer (SAL) to the north and west that will continue to cause the storm problems. The relatively cool SSTs and dry air mean that any re-development of the storm will be slow to occur. NHC has given the system a medium (30 - 50% chance) of becoming a tropical depression again by Sunday morning. Only one reliable model, the NOGAPS, is predicting regeneration of TD 2. The NOAA Hurricane Hunters are flying research missions into the remnants of TD 2 today and Saturday.

I'll have an update Saturday morning, or earlier, if significant developments occur.

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: 884 - 834

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 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114Blog Index

Quoting hurricane23:
Watch it hit somewere near Nicaragua...


I wouldn't be shocked... Every time they show the big one coming it seems to turn off and hit somewhere else or never form.
Member Since: Posts: Comments:
12Z UKMET now pretty similar to 12Z GFDL...further South!
Member Since: Posts: Comments:
The GFDL is the only model noteworthy of shifting a bit to the south. Even at that point the shortwave should create enough of a weakness to bring the system over the Greater Antilles
Member Since: Posts: Comments:
879. IKE
Quoting Patrap:
Ike ,check out the scale on the Bottom Image,Lotsa Flavor out there in that...








Looks like we'll get rain over the weekend.
Member Since: Posts: Comments:
Quoting reedzone:
Who is the culprit that is putting the virus on this blog? My computer on firefox keeps freezing on most of the times I go on here.. I want to know NOW!


I suggest you fill out a service ticket and get In Line,consider it FEMA ice waiting practice reedzone
Member Since: Posts: Comments:
Quoting KEHCharleston:
Yea.. weird. The floor is a mess. Looks like the wall blew OUT, not in. Yikes!


It can happen. I was down in Punta Gorda after Charley and saw that a few times.
Member Since: Posts: Comments:
Watch it hit somewere near Nicaragua...
Member Since: Posts: Comments:
Quoting largeeyes:
That picture looks photoshopped. Maybe it's the brightness of outside versus in, but somethings odd about it.

I agree. I've seen my share of photoshopped images.
Member Since: Posts: Comments:
Quoting P451:
12 Z Models...

CMC 144HR




GFDL 126HR




GFS 168HR




HWRF 126HR





Nice collective post
Member Since: Posts: Comments:
Ike ,check out the scale on the Bottom Image,Lotsa Flavor out there in that...






Member Since: Posts: Comments:
Quoting jeffs713:

I find it interesting how the computer desk and bedspread are in fairly organized shape, but the wall is missing.
Yea.. weird. The floor is a mess. Looks like the wall blew OUT, not in. Yikes!
Member Since: Posts: Comments:
Who is the culprit that is putting the virus on this blog? My computer on firefox keeps freezing on most of the times I go on here.. I want to know NOW!
Member Since: Posts: Comments:
How awesome! I have a lot of respect for those guys!
How is school? Or did you start the semester yet?


yeah i thought you would know him he was on the news for saying that shooting victim's life in Lafayette....and no i didn't start the semester yet i start on the 24th(hopefully) lol
Member Since: Posts: Comments:
The national hurricane center Atlantic basin storm probability looks like my son colored it.

I hope they all are fish storms. They are tearing down a high school piece by piece right now on my street. The debris field would destroy many a home insufficiently prepared.

Member Since: Posts: Comments:
Been hit one too many times to be exact. So yea, watching the tropics to see if I'm striking out on round 3. Lili did nothing but cause my orange tree to start growing in sideways. Rita and Ike gave me a that wonderful house on the water I wanted. Just a tad bit earlier than expected, didn't think we'd have one until retirement. lol
Member Since: Posts: Comments:
Wow, the models shifted south...
Member Since: Posts: Comments:
Quoting Patrap:


Hers a FREE tip...if your prepping your Home with Plywood,Plylox clips,Armor,Kevlar,..best to Get up da road and watch it on CNN.

Above is a Home post CHarley with all those Fancy smancy steps included.

I'll bail if I gotta Pat....just like to take a few precautions in case it help. Heck, hubby want to find GIANT bungee cords to secure the roof to the slab!
Member Since: Posts: Comments:
863. IKE
Quoting tornadofan:
How much longer until the 12z Euro?


Comes out at 2 pm CDST.
Member Since: Posts: Comments:
That picture looks photoshopped. Maybe it's the brightness of outside versus in, but somethings odd about it.
Member Since: Posts: Comments:
ex-TD2 is now in 5-10kts wind shear

Link
Member Since: Posts: Comments:
Quoting tornadofan:
How much longer until the 12z Euro?


Should be out at 2:55 PM EDT
Member Since: Posts: Comments:
90l doesnt look so good.. whats everyone gonna do if this one peters out??
Member Since: Posts: Comments:
Quoting louisianaboy444:
Delcambre is a great place! Lafayette here

Hey hannah! My dads a firefighter in Lafayette...hes a district chief to be exact

How awesome! I have a lot of respect for those guys!
How is school? Or did you start the semester yet?
Member Since: Posts: Comments:
856. slavp
Quoting LouisianaWoman:


Neighbor indeed! You're just a stones throw away.
LOL At my age, not sure how far I can throw one though!!! Lol
Member Since: Posts: Comments:
Quoting Patrap:


Hers a FREE tip...if your prepping your Home with Plywood,Plylox clips,Armor,Kevlar,..best to Get up da road and watch it on CNN.

Above is a Home post CHarley with all those Fancy smancy steps included.


It has always amazed me that you can have a wall blown out and still have everything nice and neat on that computer stand. I witness a lot of crazy post hurricane things like that (frances and jeanne).
Member Since: October 9, 2008 Posts: 0 Comments: 204
Aww, I want her room! She's got the best view in the house, Patrap!
Member Since: Posts: Comments:
You can tell we've been hit often.. Lots of Southern Louisianaians here keeping a close eye.. Great job keeping us informed guys!
Member Since: Posts: Comments:
Another Post Charley Image,..wanna check da Oil and maybe the Washer too Buddy?

Member Since: Posts: Comments:
Quoting IKE:


What model is that? Caribbean bound whatever it is?


UKMET
Member Since: Posts: Comments:
850. IKE
Quoting NEwxguy:


See you responded,ROFL


I'm hoping he'll finally get the message.

That will be my last response to him pertaining to that ?
Member Since: Posts: Comments:
Quoting CaicosRetiredSailor:
What models will be the first to incorporate the data from the reconnaissance flights below?


WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1000 AM EDT FRI 14 AUGUST 2009
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 15/1100Z TO 16/1100Z AUGUST 2009
TCPOD NUMBER.....09-078

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY: PSBL LOW LEVEL INVEST
FOR 16/1800Z NEAR 17.0N AND 55.0W ON THE REMNANTS
OF TD-02.
3. NOTE: 1- THE G-IV WILL FLY A RESEARCH MISSION AROUND
THE REMNANTS OF TD-02 TODAY DEPARTING TBPB 14/2000Z
.
2- BOTH NOAA43 AND G-IV WILL FLY RESEARCH MISSIONS
IN AND AROUND THE REMNANTS OT TD-02 DEPARTING TBPB
15/2000Z.


-------------------

CRS


They will have till about 10:00 PM EST tonight to get any data into the 00Z GFS model run. You can check http://www.nco.ncep.noaa.gov/pmb/nwprod/realtime/gfs/t00z/index.shtml under dropw to see the count, or select the summary and it will also be displayed.
Member Since: Posts: Comments:
Ike, just hung up the phone with ex-wife. She can see the runway at Keesler AFB. She said all morning they have been bringing planes out of hangers. She said she didn't know what was going on but figured they were going to do some training flights, as usual. Not sure if that's the case but I know I was there Wed. to she the kids and only had one plane on tarmat.
Member Since: Posts: Comments:
Quoting IKE:


90L is THREE-THOUSAND MILES away from south Florida.

No one on here can answer your question.



See you responded,ROFL
Member Since: Posts: Comments:
Delcambre is a great place! Lafayette here

Hey hannah! My dads a firefighter in Lafayette...hes a district chief to be exact
Member Since: Posts: Comments:
Quoting IKE:


LOL...he's asked the same question a hundred times.

cued up for ya!


Thanks Budster... It sounds much better than when I try to sing it
Member Since: Posts: Comments:
Quoting Patrap:


Hers a FREE tip...if your prepping your Home with Plywood,Plylox clips,Armor,Kevlar,..best to Get up da road and watch it on CNN.

Above is a Home post CHarley with all those Fancy smancy steps included.

I find it interesting how the computer desk and bedspread are in fairly organized shape, but the wall is missing.
Member Since: Posts: Comments:
Quoting slavp:
Well Howdy neighbor!!! Erath here!!! LOL


Neighbor indeed! You're just a stones throw away.
Member Since: Posts: Comments:


Hers a FREE tip...if your prepping your Home with Plywood,Plylox clips,Armor,Kevlar,..best to Get up da road and watch it on CNN.

Above is a Home post CHarley with all those Fancy smancy steps included.
Member Since: Posts: Comments:
839. IKE
Quoting Drakoen:
NEW TROPICAL STORM FORECAST TO DEVELOP AFTER 12 HOURS
FORECAST POSITION AT T+ 12 : 11.3N 28.9W

VERIFYING TIME POSITION STRENGTH TENDENCY
-------------- -------- -------- --------
00UTC 15.08.2009 11.3N 28.9W WEAK
12UTC 15.08.2009 11.8N 33.1W WEAK LITTLE CHANGE
00UTC 16.08.2009 11.3N 36.6W WEAK LITTLE CHANGE
12UTC 16.08.2009 11.7N 39.7W WEAK INTENSIFYING SLIGHTLY
00UTC 17.08.2009 12.8N 43.5W MODERATE INTENSIFYING SLIGHTLY
12UTC 17.08.2009 13.4N 47.0W MODERATE INTENSIFYING SLIGHTLY
00UTC 18.08.2009 14.2N 50.4W MODERATE LITTLE CHANGE
12UTC 18.08.2009 14.8N 54.2W MODERATE LITTLE CHANGE
00UTC 19.08.2009 15.8N 57.7W STRONG INTENSIFYING SLIGHTLY
12UTC 19.08.2009 16.0N 61.0W STRONG LITTLE CHANGE
00UTC 20.08.2009 16.6N 64.4W STRONG INTENSIFYING SLIGHTLY
12UTC 20.08.2009 17.4N 67.9W STRONG LITTLE CHANGE


What model is that? Caribbean bound whatever it is?
Member Since: Posts: Comments:
Dry air now has Ex TD2 almost totally surrounded and being a small system it is having a hard time insulating itself. This is causing the convection to weaken every time it flares up. Compared to this morning there is now more dry air to the S and SE of it not to mention the very dry conditions to the W.

This does not bode well for a recovery effort IMO

WV image
Member Since: August 19, 2006 Posts: 0 Comments: 15842
Quoting LouisianaWoman:
I chatted with you a bit last night, LB. I'm from Delcambre, the town that is technically smaller than your hometown of Crowley. ;)

Delcambre is a great place! Lafayette here
Member Since: Posts: Comments:
836. IKE
Quoting PanhandleChuck:


Come on IKE, I figure that it's about 2800 miles away. Surely we can predict where it's gonna hit now. LOL


LOL...he's asked the same question a hundred times.

cued up for ya!
Member Since: Posts: Comments:
Quoting alaina1085:


My kid hit the enter button before I was done lol. Anywho, we like to see whats going on and go outside like idiots.


We do the same thing until you get that one heavy squall and say that is enough. Luckily the house I'm in now has some clear shutters. Hopefully won't have to use them.
Member Since: October 9, 2008 Posts: 0 Comments: 204
former td2 looks more impressive this afternoon imo
Member Since: Posts: Comments:

Viewing: 884 - 834

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 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114Blog 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.

Local Weather

Overcast
56 °F
Overcast