Tropical Depression Seven forms

By: Dr. Jeff Masters , 2:25 PM GMT on August 14, 2011

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The latest in our unusual number of weak tropical cyclones this season, Tropical Depression Seven, has formed to the southeast of Bermuda. Unless you live in Bermuda, TD 7 is not going to be a concern. Radar out of Bermuda shows an area of rain on the northern side of TD 7 beginning to approach the island, and rain from the storm will likely affect the island tonight and on Monday. TD 7 is not well-organized, and has only limited heavy thunderstorms, as seen on visible satellite images. While wind shear is a low 5 - 10 knots, dry air surrounds TD 7, and is keeping the storm from intensifying. None of the computer models foresee that TD 7 will ever become more than a weak tropical storm.


Figure 1. Morning satellite image of TD 7.

92L
TD 7 isn't the only system Bermuda needs to watch, Invest 92L is a day behind it, and will follow a path very similar to TD 7's. The disturbance will pass close to Bermuda on Tuesday, bringing the island a second round of tropical rains. However, Invest 92L is very disorganized, as seen on recent visible satellite loops. Dry air and close proximity to TD 7 will likely keep 92L from showing significant development over the next two days, with NHC giving the system just a 30% chance of developing into a tropical depression by Tuesday morning.

Elsewhere in the tropics
The disturbance midway between the Lesser Antilles Islands and the coast of Africa we've been tracking over the past few days, Invest 93L, has fallen apart and is no longer a threat to develop. This system will need to be watched once it enters the Caribbean later this week, though. None of the reliable models for predicting tropical cyclone formation predict development of this system or any new disturbances over the coming week.

Jeff Masters

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1725. emguy
Quoting mrsalagranny:
Is that 93L?


Yes...
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1724. emguy
Quoting mrsalagranny:
Good morning everyone.Up and at it early this morning.Getting baby off to school>First day for Mobile.Anyways 93L, does anyone think it will be reborn today?Or is the dry air still hindering her convection? TIA


Dry air shouldn't be a factor for this one right now...There is dry air ahead of it, but the wave is embedded in a core of deep moisture. Not an issue at this time.
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Quoting BahaHurican:
Coming through!!!!

Is that 93L?
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good morning all characters looks like the windwds are finally going to get a dose of heavy rain 6-8 inches?
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1721. emguy
Quoting BahaHurican:
Coming through!!!!



Just a note...it is definately firing up and pulling in at the moment, but the general vorticity center would likely be SE of all the major convection. Lets just say somewhere around 13 N 56 W as a rough guess. It will require more time, but dry air is not an issue for this one. Good front running moisture of this one...we have seen this several times before. One of the most impressive storms was Ivan (2004), which had a solid dry air zone ahead of the system all the way at this point.
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Good morning everyone.Up and at it early this morning.Getting baby off to school>First day for Mobile.Anyways 93L, does anyone think it will be reborn today?Or is the dry air still hindering her convection? TIA
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Quoting ackee:
thanks for a response my link which is Allan Huffman weather model data is not working too off to work hav a good day


You have a good day too. :) Yeah that's the link I have that I can actually make heads or tails out of. We'll have to see if 93l will get itself going today. He liked DMAX looks like.
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Trudy just turned to the northeast.

http://www.weather.bm/IRsatelliteImage.asp

http://www.weather.bm/radarLarge.asp
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1717. ackee
Quoting AtHomeInTX:


Probably not. It's had no respect. Lol. Good morning all. Anyone know what the EURO showed last run? My links not working. It's ok. I'm not having withdrawals or anything. LOL.
thanks for a response my link which is Allan Huffman weather model data is not working too off to work hav a good day
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Morn'n back at 'cha!
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Quoting ackee:
DO u think the NHC will give it a yellow circle at 8am


Probably not. It's had no respect. Lol. Good morning all. Anyone know what the EURO showed last run? My links not working. It's ok. I'm not having withdrawals or anything. LOL.
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Good morning all who are up early and to those who read back.
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1713. ackee
Quoting BahaHurican:
Coming through!!!!

DO u think the NHC will give it a yellow circle at 8am
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1712. RTLSNK
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Coming through!!!!

Member Since: October 25, 2005 Posts: 19 Comments: 22322
Quoting Guysgal:



Gertrude is a female name whose origin is Old German. It means "sword bearer" and peaked in popularity around 1880s.
Trudy is the more common abbreviation seen these days.
Member Since: October 25, 2005 Posts: 19 Comments: 22322
1709. Guysgal
Quoting largeeyes:
Gert - short for Gertrude, a womans name. A really old womans name, but a womans name.

I still want to know who broke the satelite images.



Gertrude is a female name whose origin is Old German. It means "sword bearer" and peaked in popularity around 1880s.
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1708. ackee
Quoting emguy:


300+ hours is a long way out though...especially when models are having a tough time resolving imminent development or shorter term trends. A lot can change in that timeframe. I am personally troubled with overall model performance this year. I'm thinking these "nina neutral" years are an issue for the models based on this and some other past years I have seen. Just got to refer to the climo trends when all else fails!
agree really dont trust any of the model when it comes to long trem devlopment this has really been bad after 4 days stop paying attention to the models
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Looks like x93L is about to hit some wonderful dry sinking air. If it stays an open wave it will just crash into CA like the EURO was showing. It needs to get going now.

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Morning all. So it looks like the 70 mph somebody mentioned wasn't off base at all.

And geez, it must have been quiet overnight... still on the same page...
Member Since: October 25, 2005 Posts: 19 Comments: 22322
BULLETIN
TROPICAL STORM GERT ADVISORY NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072011
500 AM AST MON AUG 15 2011

...GERT STRENGTHENS...EXPECTED TO PASS NEAR BERMUDA LATER
TODAY...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...31.3N 63.4W
ABOUT 105 MI...175 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...N OR 355 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


000
WTNT42 KNHC 150847
TCDAT2

TROPICAL STORM GERT DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072011
500 AM AST MON AUG 15 2011

GERT HAS STRENGTHENED OVERNIGHT. AN 0543 UTC AMSR-E PASS AND
DOPPLER RADAR DATA FROM BERMUDA INDICATE THAT GERT HAS A FAIRLY
WELL-DEVELOPED INNER CORE AND A SPIRAL BAND THAT WRAPS ABOUT
THREE-QUARTERS OF THE WAY AROUND THE CENTER. IN ADDITION...
SATELLITE IMAGES INDICATE THAT BANDING FEATURES HAVE BECOME MORE
ESTABLISHED DURING THE PAST SEVERAL HOURS. THE INITIAL WIND SPEED
IS INCREASED TO 50 KT...WHICH IS SLIGHTLY HIGHER THAN THE DVORAK
CLASSIFICATIONS FROM TAFB AND SAB. THERE IS STILL SOME NORTHERLY
SHEAR IMPACTING THE CYCLONE...AS SEEN IN THE UW-CIMSS SATELLITE
ANALYSIS AND THE SOUTHWARD TILT WITH HEIGHT OF THE CIRCULATION
CENTER IN THE AMSR-E IMAGERY. AN AIR FORCE RESERVE RECONNAISSANCE
AIRCRAFT WILL BE INVESTIGATING GERT LATER THIS MORNING AND WILL
PROVIDE A BETTER ASSESSMENT OF ITS INTENSITY.

THE TROPICAL STORM APPEARS TO HAVE TURNED TO THE NORTH DURING THE
PAST 6 HOURS...AND THE LATEST INITIAL MOTION ESTIMATE IS 355/12.
GERT IS FORECAST TO TURN NORTH-NORTHEASTWARD AND THEN NORTHEASTWARD
AND GAIN FORWARD SPEED DURING THE NEXT FEW DAYS AS IT BECOMES
EMBEDDED IN THE STRONGER FLOW TO THE EAST OF A DEEP-LAYER TROUGH
MOVING OFFSHORE OF THE UNITED STATES EAST COAST. THE OFFICIAL
FORECAST IS ESSENTIALLY AN UPDATE OF THE PREVIOUS ONE AND IS NEAR
THE MULTI-MODEL CONSENSUS.

SOME ADDITIONAL INTENSIFICATION OF GERT APPEARS LIKELY DURING THE
NEXT 24 HOURS AS IT REMAINS OVER RELATIVELY WARM WATER AND BENEATH
AN UPPER-LEVEL ANTICYCLONE. AFTER 24 HOURS...GERT IS FORECAST TO
MOVE OVER WATERS COOLER THAN 26C...WHICH SHOULD INDUCE SOME
WEAKENING. IN 2 TO 3 DAYS THE STORM IS FORECAST TO MOVE INTO AN
ENVIRONMENT OF STRONG SOUTHWESTERLY SHEAR AND WATERS COOLER THAN
20C...WHICH SHOULD RESULT IN EXTRATROPICAL TRANSITION DURING THAT
TIME PERIOD. THE GLOBAL MODELS ARE IN AGREEMENT THAT A FRONT WILL
ABSORB GERT IN 3 TO 4 DAYS.

INTERESTS IN BERMUDA ARE REMINDED NOT TO FOCUS ON THE EXACT FORECAST
TRACK OF GERT...AS ONLY A SLIGHT DEVIATION TO THE LEFT DURING THE
NEXT 6 TO 12 HOURS COULD BRING STRONG WINDS CLOSE TO...OR OVER...THE
ISLAND.

FORECAST POSITIONS AND MAX WINDS

INIT 15/0900Z 31.3N 63.4W 50 KT 60 MPH
12H 15/1800Z 33.5N 62.9W 55 KT 65 MPH
24H 16/0600Z 36.8N 60.8W 60 KT 70 MPH
36H 16/1800Z 40.3N 57.2W 55 KT 65 MPH
48H 17/0600Z 43.0N 51.5W 50 KT 60 MPH
72H 18/0600Z 48.0N 36.5W 40 KT 45 MPH...POST-TROP/EXTRATROP
96H 19/0600Z...DISSIPATED

$$
FORECASTER CANGIALOSI/BRENNAN
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Quoting bappit:

Mid-latitude cyclones are often just as intense as tropical cyclones and are often much larger. They occur more frequently. They occur at all times of the year, over land and water. They are more effective.

But I am repeating myself.

Right, but as you just said, these are mid-latitude cyclones. They transport heat over the mid-latitudes. Hardly over the tropics. Tropical cyclones are the best and most efficient way to remove heat from the tropics towards the poles.
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1703. emguy
Quoting reedzone:
The GFS "ghost" storm may not be too crazy.. EURO shows the same exact thing!


300+ hours is a long way out though...especially when models are having a tough time resolving imminent development or shorter term trends. A lot can change in that timeframe. I am personally troubled with overall model performance this year. I'm thinking these "nina neutral" years are an issue for the models based on this and some other past years I have seen. Just got to refer to the climo trends when all else fails!
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Quoting reedzone:
The GFS "ghost" storm may not be too crazy.. EURO shows the same exact thing!

It almost looks as big as Tip!
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The GFS "ghost" storm may not be too crazy.. EURO shows the same exact thing!
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i think its time to invest_DEACTIVATE_al922011.ren
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1699. emguy
Quoting Vincent4989:

looks better than Gertrude.


It's not better organized than Gert, but it has started to pull itself together now. Typically not a fan of fast moving waves, but this one is different. As of yesterday, the wave was basically embedded in a very elongated trough extension that came se toward the wave from 92L. A.) Gert just ate 92 L and B.) this wave has now moved far enough along that it has broke free of that trough extension and begun to turn over onto itself. In addition, looking at the tradewinds in the eastern carribean, they look like they are slowing down. This might just start to get very interesting folks...
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92L down to 10% its being eaten by the blob
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Quoting emguy:


It is the wave previously know of as 93L...It's makin a comeback...or at least trying too.

looks better than Gertrude.
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Remnants of 93L, though probably too disorganized to be called a wave.
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1695. emguy
Quoting Vincent4989:
There's some really interesting wave near the Leeward Islands. Where did that come from?


It is the wave previously know of as 93L...It's makin a comeback...or at least trying too.
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There's some really interesting wave near the Leeward Islands. Where did that come from?
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1693. emguy
Quoting HurricaneHunterJoe:
Is everyone in reflective mode?


Not in reflective mode...but in reflective mood...Gert is the story of discussion, but for me over here in Port Charlotte...yesterday was 7th anniv. of Charley.

Anyhew, recalling it and reading the Hurricane Post Summary from the National Hurricane Center, it did not get any street cred in the Tropical Weather Outlook until it's passage in the leewards, where the pressure suddenly dropped 4 millibars, then they started giving more attention.

Anyhow, I mention it because we got a wave tracking toward the leewards that is not getting any street cred right now. Watch this one folks. The strong trough that brought Charley to Florida in 2004 will not be there, but a weakness will be in place next weekend and I think the eastern 2/3 of the Gulf should keep this wave in mind. Just my 2 cents...

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TS.Gert's_6amGMT_ATCF : Starting 14August_6amGMT and ending 15August_6amGMT

The 4 short line-segments represent TS.Gert's path and
the longest line-segment is the straightline projection.

TropicalStormGert's travel-speed was 16.2mph(26k/h) on a heading of 353degrees(N)
Using straightline projection of the travel-speed&heading derived from the ATCF coordinates spanning the 6hours between 12amGMT then 6amGMT :
TS.Gert was headed toward passage over Villagedale,NovaScotia 2days4hours from now

Copy&paste 28.0n62.2w-28.1n62.9w, 28.1n62.9w-28.6n63.1w, 28.6n63.1w-29.5n63.2w, 29.5n63.2w-30.9n63.4w, bda, 29.5n63.2w-43.51n65.54w, yhz, 22.3n58.0w, 22.8n59.0w, 24.0n59.8w, 25.7n59.7w, 28.0n59.3w into the GreatCircleMapper for more info

The previous mappings (for 15August_12amGMT)
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Gert - short for Gertrude, a womans name. A really old womans name, but a womans name.

I still want to know who broke the satelite images.
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Quoting HurricaneHunterJoe:
if Gert is tracking 345 degrees, she may get very close to Bermuda.

Gert doesn't sound like a woman name though. Storm names are alternated with gender. The last one was Franklin. Do thou also think that Gert doesn't sound like a woman name?
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Is everyone in reflective mode?
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she trying to get an eyewall going,pretty weak on the west side though
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if Gert is tracking 345 degrees, she may get very close to Bermuda.
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Who broke the satelite images?
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1684. Mucinex
Quoting HadesGodWyvern:


NOAA news for the which named were officially retired in 2005

Oh! Thank You, Thank You!
Member Since: May 23, 2011 Posts: 0 Comments: 254
Quoting Tazmanian:
has any one noted that the ITCZ is really poping with t-storms tonight even no nothing march will come out of them
My guess is, this is the upswing in the MJO we are witnessing. We've been expecting it.
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1682. HadesGodWyvern (Mod)
1672. Mucinex 5:40 AM GMT on August 15, 2011
Anybody have a reliable link to proof that TS Alpha was not retired. I'm 100% sure it wasn't. But, I also can't seem to find reliable proof to back that up. Money is on the line.:)

Also, WU has all the greek-named storm maps from 2005 hitting Africa and Spain.


NOAA news for the which named were officially retired in 2005
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Thanks for the links sunlinepr :)
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ROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
1100 PM PDT SUN AUG 14 2011

FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE..

1. SHOWER AND THUNDERSTORM ACTIVITY HAS INCREASED NEAR THE CENTER OF A
LOW PRESSURE SYSTEM LOCATED ABOUT 1500 MILES WEST-SOUTHWEST OF THE
SOUTHERN TIP OF BAJA CALIFORNIA. UPPER-LEVEL WINDS ARE EXPECTED TO
BECOME MORE CONDUCIVE FOR ADDITIONAL DEVELOPMENT...AND A TROPICAL
DEPRESSION COULD FORM DURING THE NEXT DAY OR TWO. THIS SYSTEM HAS
A HIGH CHANCE...80 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS AS IT MOVES WESTWARD AT AROUND 10 MPH.
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Quoting GTcooliebai:
That's ok, I still think that is pretty substantial shift kind of like how big earthquakes shift landmasses & tilt the earth's axis.


Correcting my data, by satellite observations, it is expanding S 5.5 Km per year since 1980...

(90 to 100 km during the 17-year period)

Link

Gnite all..
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1678. Tygor
Quoting NCHurricane2009:


This forecast IS NOT GOOD...drought will generally continue....


Driest I've ever lived through, although I'm a Texas newbie of only about 7 years. 10-day outlook is a whole lotta 103 degrees, 0% chance of rain blah blah blah. We are just thankful for the 2" we've gotten this summer.
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BULLETIN
TROPICAL STORM GERT INTERMEDIATE ADVISORY NUMBER 5A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072011
200 AM AST MON AUG 15 2011

...OUTER BANDS OF GERT APPROACHING BERMUDA...


SUMMARY OF 200 AM AST...0600 UTC...INFORMATION
----------------------------------------------
LOCATION...30.8N 63.4W
ABOUT 130 MI...210 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...NNW OR 345 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES
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Quoting sunlinepr:


Sorry for my english, I should have said that the dessert is Expanding south, not moving...
It would be interesting gathering recorded and actual data to pronosticate what will effect it would have interacting with the ITCZ...
That's ok, I still think that is pretty substantial shift kind of like how big earthquakes shift landmasses & tilt the earth's axis.
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1675. Mucinex
000
ABNT20 KNHC 150533
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT MON AUG 15 2011

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM GERT...LOCATED ABOUT 130 MILES SOUTHEAST OF BERMUDA.

SHOWER AND THUNDERSTORM ACTIVITY HAS DIMINISHED IN ASSOCIATION WITH
A BROAD AREA OF LOW PRESSURE LOCATED ABOUT 550 MILES NORTH-
NORTHEAST OF THE NORTHERN LEEWARD ISLANDS. ENVIRONMENTAL CONDITIONS
ARE EXPECTED TO REMAIN ONLY MARGINALLY CONDUCIVE FOR DEVELOPMENT OF
THIS SYSTEM OVER THE NEXT COUPLE OF DAYS DUE TO PROXIMITY TO
TROPICAL STORM GERT. THIS SYSTEM HAS A LOW CHANCE...10 PERCENT...
OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES
NORTH-NORTHWESTWARD AT 15 TO 20 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BRENNAN
Member Since: May 23, 2011 Posts: 0 Comments: 254

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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.