Tropical Depression Six arrives

By: Dr. Jeff Masters , 5:14 PM GMT on August 22, 2010

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Tropical Storm Tropical Depression Six is here, but it will not be a threat to land for at least the next five days. Tropical Depression Six is a classic "Cape Verdes"-type storm common during the peak part of hurricane season. Cape Verdes-type storms are so named because they form from tropical waves that come off the coast of Africa and pass near the Cape Verdes Islands just west of Africa. Cape Verdes hurricanes are the largest and most dangerous types of hurricane in the Atlantic, since they spend a long time over water have and have of opportunity to reach full maturity. Tropical Depression Six has a ways to go before it becomes a hurricane, as the storm is embedded in a strong easterly flow of wind courtesy of the African Monsoon that is generating a moderately high 15 - 20 knots of wind shear. There is also a tropical disturbance to the northeast of TD 6 that is sucking away some moisture and is interfering with the storm's circulation. Sea Surface Temperatures (SSTs) are a warm 28°C, and the storm is embedded in a moist environment, so wind shear is the primary inhibiting factor for development. The strong east winds imparting the shear are keeping any heavy thunderstorms from developing on the east side of the center of circulation, which is exposed to view in satellite imagery (Figure 1.)


Figure 1. Afternoon satellite image of Tropical Depression Six.

Forecast for Tropical Depression Six
A ridge of high pressure will force Tropical Depression Six to the west-northwest for the next five days, and the system should increase its forward speed from its current 10 mph to 15 mph by Monday night. A powerful trough of low pressure over the mid-Atlantic Ocean will begin to pull Tropical Depression Six more to the northwest late this week, and the storm should pass well to the northeast of the Lesser Antilles Islands. It remains to be seen, however, it this trough will be strong enough to fully recurve Tropical Depression Six out to sea. The GFS predicts that Tropical Depression Six may pass close to Bermuda about eight days from now, and it is also possible that Tropical Depression Six could eventually hit the U.S. East Coast 9 - 15 days from now. However, we have no skill in making these sort of ultra-long range forecasts, and the long-range fate of TD 6 is uncertain.

Elsewhere in the tropics
The ECMWF and NOGAPS models are predicting formation of a tropical depression off the coast of Africa 3 - 4 days from now.

Jeff Masters

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Quoting Thundercloud01221991:
Does anyone know why they are only forecasting a 5 mph increase in winds over 12 hours??? this has been intensifying faster then that over the past 12 hours and conditions will improve


Kimberlain's one of the more conservative forecasters. Although, his reasoning is probably shear related which is still undoubtedly affecting Danielle. Slow strengthening is a reasonable forecast, though this is probably a touch on the low side. Especially as Danielle could be 65mph already.

If it's only kept her in check so far, who knows what she'll do given the right opportunity. Looks like, at least for the next three days, shear'll be a bit of a roadblock.
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Does anyone know why they are only forecasting a 5 mph increase in winds over 12 hours??? this has been intensifying faster then that over the past 12 hours and conditions will improve
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2780. HadesGodWyvern (Mod)
METEO FRANCE update
====================

Tropical storm "DANIELLE", 1000 near 14.2N35.9W by 23 at 03 UTC,
moving northwest at 11 kt, expected severe tropical storm near
15.9N40.3W by 24 at 00 UTC then near 17.1N43.3W by 24 at 12 UTC.

New low expected 1010 near 11N18W by 23 at 12 UTC, then 1010 near
14N20W by 24 at 12 UTC.

Low expected 1008 near 20N16W by 23 at 12
UTC, expected over CAP TIMIRIS by 23 at 18 UTC, then merging with the last one.
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Morning.

Selected parts:


THE BURSTING PATTERN AND THE PLACEMENT OF THE
SURFACE CENTER SUGGESTS THAT DANIELLE CONTINUES TO UNDERGO EASTERLY
VERTICAL WIND SHEAR BUT POSSIBLY NOT AS MUCH BEFORE. DVORAK
INTENSITY ESTIMATES ARE 3.0 AND 4.0 FROM SAB AND TAFB...
RESPECTIVELY...AND 3-HOUR AVERAGE ADT VALUES ARE 3.4. USING A BLEND
OF THESE INTENSITY ESTIMATES...THE ADVISORY INTENSITY IS RAISED
CONSERVATIVELY TO 50 KT.

TRACK MODEL SOLUTIONS ARE FAIRLY
TIGHTLY CLUSTERED AND HAVE SHIFTED EASTWARD FROM THE PREVIOUS
PACKAGE. THE OFFICIAL NHC TRACK FORECAST IS ADJUSTED EASTWARD AND
IS CLOSE TO...BUT NOT AS FAR EAST AS...THE MULTI-MODEL CONSENSUS.

85kts by 120 days according to Kimberlain.
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2778. Walshy
Tropical Storm Danielle
Wind: 60 MPH Location: 14.8N 37.1W Movement: WNW



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SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...14.8N 37.1W
ABOUT 850 MI...1365 KM W OF THE SOUTHERNMOST CAPE VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/HR
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 14 MPH...22 KM/HR
MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES
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2775. HadesGodWyvern (Mod)
National Hurricane Center
Tropical Cyclone Advisory #7
TROPICAL CYCLONE FRANK (EP092010)
9:00 AM UTC August 23 2010
================================

SUBJECT: "FRANK" Maintains Its Strength

At 9:00 AM UTC, Tropical Storm Frank (998 hPa) located at 14.3N 97.5W or 90 NM south southwest of Puerto Escondido, Mexico has sustained winds of 50 knots with gusts of 60 knots. The cyclone is reported as moving west at 7 knots.

Gale Force Winds
================
50 NM from the center

Forecast and Intensity
=========================
24 HRS: 15.0N 100.0W - 65 knots (SVR Tropical Cyclone - SSHS 1)
48 HRS: 16.4N 102.8W - 70 knots (SVR Tropical Cyclone - SSHS 1)
72 HRS: 17.5N 105.5W - 70 knots (SVR Tropical Cyclone - SSHS 1)

Tropical Cyclone Warnings/Watches
====================================
A Tropical Storm Warning is in effect for Mexico from Puerto Escondido westward to Zihuatanejo

A Tropical Storm Watch is in effect for Mexico from west of Zihuatanejo to Punta san Telmo
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2774. xcool
bye all.
Member Since: September 26, 2009 Posts: 2 Comments: 15670
2773. xcool
errantlythought .she eyes for min the lost
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Quoting xcool:


Scratch that! That's a kelvin bar! DERP!

However, this does give a better clue to the COC. If the IR can be trusted to show the center from its expansion point, she's riding south of 14N. Or just at it.
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Quoting BreadandCircuses:


My bad, I typed in LSU on the "awesomebar" lol and it brought uplatest wv.jpg, evidently it is not updated if you do it that way, lol


Actually it updated just a few minutes before you removed it to the latest imagry, so I think their servers may have just not updated til' after I had posted.

Either that or I somehow had an 8 hour image cached on a machine I dont usually use for WXing.

Either way, weird XD
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2770. xcool
HadesGodWyvern .noway.?
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2769. HadesGodWyvern (Mod)
Low expected
1006 by 19N16W at 23/03 UTC, moving to south of CAP TIMIRIS in
daytime, filling 1009 at the end. Low expected deepening 1011 by
10N15W at 23/03 UTC, moving northwestward merging with the last
one.
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2768. xcool
Member Since: September 26, 2009 Posts: 2 Comments: 15670
2767. xcool
:)
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Quoting BreadandCircuses:


That's 8 hours old.

edit: Nevermind, then. Finally bloody cached correctly.
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Nite everyone.
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Quoting jason2010xxxx:
i do not like the look at this tropical low


That is much further South starting out.
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2760. smuldy
ya it does appear to be heading due west but amazingly the 2am steering map has the trough already at 30n in august maybe the early eastern recurve will happen and the models are correct lets see how fast the northern synoptic pattern heads west
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2758. xcool
jason2010xxxx lolol
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2756. Grothar
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2754. xcool
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2753. Grothar
Quoting TampaSpin:


Almost due West.......which the Steering graphics show it should be almost due West.


So I'm not dreaming?
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Quoting Grothar:
Does this look like a NW movement or WNW? I know it's late,but what am I missing ?



Almost due West.......which the Steering graphics show it should be almost due West.
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2750. xcool
byee rob
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2749. xcool
wnw move
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2747. Grothar
Does this look like a NW movement or WNW? I know it's late,but what am I missing ?

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2743. xcool



update
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2742. xcool

:0
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Gotta say as much as Jason gets picked on, he has a great taste for music, but his forecasting is still to be determined with Danielle.....LOL........nice job Jason.....Just kidding of course.
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2739. xcool
lmao
Member Since: September 26, 2009 Posts: 2 Comments: 15670
2738. xcool
model support to
Member Since: September 26, 2009 Posts: 2 Comments: 15670
Quoting jason2010xxxx:


Jason, ROFL, LOL. That music on that video sure beats the local on the 8s music on the weather channel. I think Danielle likes that rock music. Careful, play it too long, and she might strengthen too much, LOL!
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2735. xcool
TampaSpin 7lol
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Quoting Stormchaser2007:
Oh well. Not really worth arguing over.

Anyways, this wave will likely be our next invest.



That tropical wave, yep it looks good. Just entertaining thought here, maybe this could eventually become major hurricane earl eventually, that would be neat. As far as I remmeber, there has never been a major hurricane earl (cat. 3 or higher) before. The strongest earl I know was cat. 2 earl in 1998.

Earl is such a funny name for a powerful storm IMO.
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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.