ATL: GABRIELLE - Remnants - Discussion

[TropicalAnalystwx13]

The stationary people were right. I can't believe it. A staller here is more likely to move north. However a staller here is not good for development because the graveyard will more likely crush it - especially in 2013. Circulation is 9/10th of the law so we'll see if it survives.

The EC is not a graveyard. One really needs to stop listening to the disproven John Hope Rule

Earlier in the thread I posted the 12 storms that formed in the last 10 years in the EC. That means we average 1.2 storms there a season

I agree with you, IMO the graveyard in the eastern Caribbean only happens on certain years and or certain times of the year, like you said many storms have formed here or have moved through this area without a problem.

And those storms would be the exception, not the rule. The East Caribbean is generally unkind to tropical cyclone year round. The narrow corridor of water between the Greater Antilles and Hispaniola allows for the circulations of developing systems to suck in dry air coming off the downslope of Hispaniola and off northern South America. In addition, the trade winds accelerate ahead of developing disturbances, south of Hispaniola, which reduces surface convergence and promotes sinking air.

[blp]

What I see happening here is that the LL disturbance north of Barbados will be approached by the new LL disturbance (part of TW) east of it and they will combine their energy and kick off the development. Once this happens (24 - 36 hours) then it will move to the WNW over PR and close to the SE Bahamas. There it will sit again and slowly drift while the pattern changes (trof lifts out and ridge builds in over it) after that the storm will start to intensify and pose a potential treat to Florida to South Carolina.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

I don't see anything at the lower levels or mid level associated with the blob further east. See the 850mb chart below. It might just have the effect to enhance the environment and create more instability for thunderstorm development to grow over the mid level center close to Barbados. If anything is going to get going the Barbados area is the most capable area to sustain development.

http://img707.imageshack.us/img707/6731/7qv.gif

[blp]

Looks to me like that ULL over Haiti is starting a dive toward the SW which would create a favorable situation for our low.

http://www.ssd.noaa.gov/goes/east/watl/wv-animated.gif

[cycloneye]

More low level convergence. Maybe a start??

[SFLcane]

I just dont see that favorable enviroment right now based on that WV loop posted above all i see is multiple ull's with sinking air impacting 97L.

Maps may not show it but i think moderate windshear is impacting the system.

[ScottNAtlanta]

More low level convergence. Maybe a start??

http://oi40.tinypic.com/29oibyf.jpg

Thats the most convergence I've seen over this system from the start.

[HurriGuy]

IMO...it would mildly shock me if this forms. It is too broad, it will take too long to really get some convection around a LLC and with its proximity to land and looking at the model trends, it will face an even greater slate of problems. But ....I'm just a watcher.haha

[NDG]

I agree with you, IMO the graveyard in the eastern Caribbean only happens on certain years and or certain times of the year, like you said many storms have formed here or have moved through this area without a problem.

And those storms would be the exception, not the rule. The East Caribbean is generally unkind to tropical cyclone year round. The narrow corridor of water between the Greater Antilles and Hispaniola allows for the circulations of developing systems to suck in dry air coming off the downslope of Hispaniola and off northern South America. In addition, the trade winds accelerate ahead of developing disturbances, south of Hispaniola, which reduces surface convergence and promotes sinking air.

Like I said that only happens on certain years or certain times of the year, and it all has to do with how strong the trade winds are this area of the Caribbean due to the combination of how strong the Bermuda ridge is and how low the pressures in NW Colombia are, some years stronger than others so thus the "graveyard" name applies, IMO.
2007 was a good example, I remember Felix and Dean formed east of the Lesser Antilles that were forecasted to move through the "graveyard" many people on this site & other sites calling for the weakening of them, many were even saying that it was going to suck dry air from S.A. that was going to weaken them, if anything they continued to strengthen as they tracked through the eastern Caribbean.
Felix in particular was barely a TD when it entered the eastern Caribbean and became a major hurricane as it tracked through the famous "graveyard".

[cycloneye]

Here is what the folks from the San Juan NWS think about this wave and the effects in PR.

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
1059 AM AST MON SEP 2 2013

.UPDATE...THE 02/12Z SOUNDING CAME IN REASONABLY WET AND THIS IS
UP SOMEWHAT FROM BOTH THE TWO PREVIOUS SOUNDINGS. ALSO LOW LEVEL
MOISTURE HAS INCREASED UP THROUGH 550 MB.

.DISCUSSION...SHOWERS ARE AT LEAST SCATTERED OVER THE ATLANTIC AND
OFFSHORE WATERS IMMEDIATELY EAST OF PUERTO RICO...WITH A FEW
SHOWERS APPROACHING THE NORTHERN U.S. VIRGIN ISLANDS. THE GFS ALSO
SEEMS TO HAVE A GOOD HANDLE OF THE LOW LEVEL CIRCULATION AROUND
THE TROPICAL WAVE...THE APEX OF WHICH HAS NOT YET ENTERED THE
CARIBBEAN...BUT IS QUITE CLOSE TO DOING SO. SCATTERED LIGHT
SHOWERS ARE SEEN IN THE OBSERVATIONS IN THE LESSER ANTILLES AND NO
WINDS ARE INDICATING TROUGH PASSAGE. BUOY 42060...OUTSIDE OF OUR
FORECAST AREA TO THE SOUTHEAST BUT STILL IN THE CARIBBEAN ALSO
NOTES FALLING PRESSURES...BUT LESS RAPIDLY THAN YESTERDAY. THIS
DOES NOT AUGUR WELL FOR THE VERY STRONG WAVE PREVIOUSLY
ANTICIPATED BY SOME OF THE MODELS AND HAVE BACKED OFF SOME OF THE
HIGHER QPFS FOR THAT TIME. WILL LIKELY STILL HAVE URBAN AND SMALL
STREAM FLOODING AND CANNOT RULE OUT AREAS OF FLASH FLOODING SHOULD
THUNDERSTORMS FORM IN LINEAR FASHION OVER PUERTO RICO. LESS RAIN
IS EXPECTED IN THE U.S. VIRGIN ISLANDS.

AT THIS TIME WE DO NOT EXPECT A WATCH TO BE ISSUED...BUT WILL
CONTINUE TO MONITOR PROGRESS AND DEVELOPMENT OF THE WAVE
OVERNIGHT.

[ROCK]

this is from HurricaneDave, sounds ominous:

It could move between pr and / dr. When this system enters the bahamas it will have moved toward the weakness in west atlantic/bahamas. Conditions will favor rapid intensification by day 5. Beyond that it is speculative on where this goes and how strong and ignore the blue lines.

HurricaneDave Discov Everyone in hispanola/pr/cuba and east coast should be mindful to closely watch this system given the seemingly favorable conditions and no apparent shortcoming of ingrediants to intensify this.

Who is HurricaneDave and what makes him an authority on tropical cyclones? Does he have a good track record of accuracy?

he frequently posts on wxrisks facebook. he did drop his seasonal numbers to 11/2/1 i think long before anyone but me did.

Hurricane Dave? really? if you are taken his advice then good luck. He is not a MET and half the time he is wrong.

[NDG]

I just dont see that favorable enviroment right now based on that WV loop posted above all i see is multiple ull's with sinking air impacting 97L.

Maps may not show it but i think moderate windshear is impacting the system.

The sounding from Barbados shows all the evidence you need to see that there is no windshear over 97L, dry air entraining into the system from the soroundings has been the big problem for 97L for the past 48 hrs or so.

[tailgater]

I been looking at the obs near 97L, I may have been mistaken when I said earlier that this invest is gone. Take a look at windfield, any llc would be SW of Barbados.

http://rammb.cira.colostate.edu/ramsdis ... display=12

The MLC north of Barbados makes it hard to see.

[NDG]

BTW, 12z GFS now shows a stronger vorticity with 97L to track towards in between P.R. and Hispaniola through the next 72 hrs.

[SFLcane]

I just dont see that favorable enviroment right now based on that WV loop posted above all i see is multiple ull's with sinking air impacting 97L.

Maps may not show it but i think moderate windshear is impacting the system.

The sounding from Barbados shows all the evidence you need to see that there is no windshear over 97L, dry air entraining into the system from the soroundings has been the big problem for 97L for the past 48 hrs or so.

Again thats just my take just think there is some light/moderate shear affecting it. Until it mixes out the dry air i see nothing developing. Bored of this season

[northjaxpro]

Yep, dry air at the mid levels is really hampering 97L right now.

[blp]

I been looking at the obs near 97L, I may have been mistaken when I said earlier that this invest is gone. Take a look at windfield, any llc would be SW of Barbados.

http://rammb.cira.colostate.edu/ramsdis ... display=12

The MLC north of Barbados makes it hard to see.

I actually think it is in a better position today than yesterday. Yesterday we had a very elongated system with very little mid level vorticity support. The system will be able to consolidate better today.

If you look at the 850mb level today it is still elongated but looks to be developing two pockets of stronger vorticity within the broad area. One pocket is off the coast of SA while the other is closer to our mid level area in Barbados. I think what is going to happen is that the pocket close to SA is going to break off and head west while the other pocket will consolidate with the mid level center around Barbados and that will be the dominant area because it has the mid level support. This is why the models had the two areas.

[blp]

More low level convergence. Maybe a start??

http://oi40.tinypic.com/29oibyf.jpg[/img]

Indeed, and two areas of strongest convergence supports my thinking of the two areas one off the SA coast and the other around Barbados. I think we are starting to see the two areas develop now.

[TheStormExpert]

Looking at the graphic below I see very little mid-level dry air. Could someone explain where the dry air is that they are seeing?

[vbhoutex]

this is from HurricaneDave, sounds ominous:

It could move between pr and / dr. When this system enters the bahamas it will have moved toward the weakness in west atlantic/bahamas. Conditions will favor rapid intensification by day 5. Beyond that it is speculative on where this goes and how strong and ignore the blue lines.

HurricaneDave Discov Everyone in hispanola/pr/cuba and east coast should be mindful to closely watch this system given the seemingly favorable conditions and no apparent shortcoming of ingrediants to intensify this.

Who is HurricaneDave and what makes him an authority on tropical cyclones? Does he have a good track record of accuracy?

he frequently posts on wxrisks facebook. he did drop his seasonal numbers to 11/2/1 i think long before anyone but me did.

And??? Just because he agrees with you and posts on DT's site makes him an authority? I have posted over there and on other sites. Does that make me an authority?

[Alyono]

:darrow: Looking at the graphic below I see very little mid-level dry air. Could someone explain where the dry air is that they are seeing?

You cannot see mid level dry air on WV. It mainly shows upper level WV

TPW products are a better bet