Atlantic Invest Thread 2011

[Iceberg]

I am not sure on that re-curve yet, the globals that should be massively best placed to forecast any ridge extension and or east coast trough 5-6 days out have no real agreement either operationally or Ensemble. The re-curve will almost certaintly happen, but might yet place Florida or S/N Carolina into the cone.

[summer blizzard]

http://www.ssd.noaa.gov/goes/east/tatl/flash-rb.html

Two centres?

Or worse, 2 storms?

Edited July 31, 2011 by summer blizzard

[Somerset Squall]

I'm watching the tropical wave between 91L and the west coast of Africa too, looks impressive. May become a player, and dare I say it, Franklin?

[Cookie]

I'm watching the tropical wave between 91L and the west coast of Africa too, looks impressive. May become a player, and dare I say it, Franklin?

something to keep an eye on for sure!

[Iceberg]

Recon are just flying through that earlier feature. 091l is looking very good on visual excellent inflow, outflow and banding a def ts imo

[Iceberg]

there has been a significant shift eastwards with the latest GFS taking Emiy not a million miles from Miami, the globels seem to be taking the region stronger and stronger delaying the recurve, so any hurricane pretty much hits the entire Caribbean island chain.

[Somerset Squall]

Interesting that developing little feature to the west of 91L too, I wonder if it will develop any further and, if so, could it impact 91L at all?

[mezzacyclone]

Interesting that developing little feature to the west of 91L too, I wonder if it will develop any further and, if so, could it impact 91L at all?

does such a phenomena as a "binary tropical depression" exist?

Trying to decipher the following but need to do a lot of data trawling,,,?

After tracking across Puerto Rico, the forecast becomes a lot more hazy as a ridge of high pressure will break down as a strong upper-level trough of low pressure pushes off of the US East Coast. This could help and lift Emily northward and then northeastward away from the US Southeast coast. It is not that clear cut, however, as the GFS and European ensemble guidance are forecasting that a ridge of high pressure will build back in by late next week and if this happens would cause Emily to potentially turn back towards the US Southeast coast. Given that this is still 6 days or so away, the forecast uncertainty on where Emily may go is pretty high

[Iceberg]

Recon keep losing contact yes it's called a Fujisawa effect. Hope that was Spelt right sorry I am only phone ATM

Re the ridge yes its all down to the speed of Emily over the next 7 days

[Somerset Squall]

Yep, it's the Fujiwara Interaction, this phenomenon happened not long ago with Typhoon Ma-on and Tropical Storm Tokage in the West Pacific. The two disturbed areas are very close here, though 91L is far more dominant at present.

[jimbo36]

latest obs

A LARGE AND ELONGATED LOW PRESSURE SYSTEM IS LOCATED ABOUT 575

MILES EAST OF THE NORTHERN WINDWARD ISLANDS. ALTHOUGH THIS SYSTEM

HAS CHANGED LITTLE IN ORGANIZATION TODAY...ENVIRONMENTAL CONDITIONS

ARE EXPECTED TO REMAIN CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM

LATER TODAY OR ON MONDAY. THIS SYSTEM HAS A HIGH CHANCE...NEAR 100

PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS

AS IT MOVES WEST-NORTHWESTWARD NEAR 15 MPH. AN AIR FORCE RESERVE

UNIT RECONNAISSANCE AIRCRAFT IS EN ROUTE TO DETERMINE IF THIS BROAD

DISTURBANCE HAS DEVELOPED A WELL-DEFINED SURFACE CIRCULATION

CENTER. IF THE LOW BECOMES A TROPICAL CYCLONE LATER TODAY...

TROPICAL STORM WATCHES OR WARNINGS WOULD LIKELY BE REQUIRED FOR

PORTIONS OF THE NORTHERN WINDWARD ISLANDS AND THE LEEWARD ISLANDS.

INTERESTS IN THESE AREAS SHOULD CLOSELY MONITOR THE PROGRESS OF

THIS DEVELOPING SYSTEM.

Edited July 31, 2011 by jimbo36

[Guest]

The first major hurricane? are they a little late in developing this year?

[Cookie]

The first major hurricane? are they a little late in developing this year?

nope we're bang on track this year, nothing unusall with this year at all thus far!

[Cookie]

Bit messy out thier tonight, not looking as good as it was!

[mezzacyclone]

No clear circulation etc. so still 91L tropical wave whereas yesterday many anticipated a TD at least and possibly TS by days end today (Sun 31st jul)?

10:15 UTC today

and almost 12 hrs later the "messy" picture:

Fluid dynamic physics or a storm in a teacup? lol

laters storm followers

[Paranoid]

Is it possible that mass of convection to the west is interfering with 91L's development?

[Somerset Squall]

91L is rather messy tonight, with more than one possible centre, none of which that well defined. Keeping the NHC on their toes with the latest TWO still indicating a near 100% risk of TC formation in the next 48hrs. I have never seen a system at a near 100% chance of TC formation for so long. It's taking it's sweet time.

[Somerset Squall]

Is it possible that mass of convection to the west is interfering with 91L's development?

It almost looks like they are trying to merge. That definitely would interfere with development.

[summer blizzard]

Is it possible that mass of convection to the west is interfering with 91L's development?

I would summise that yes, that has been the case.

Recent radar suggests that the two storms are now merging with one centre at the west of the storm.

With this kind of outflow already and the shear size, Emily is going to be a true monster.

[Paranoid]

I'd say the mass to the west looks in better shape than 91L at the moment. It seems to be tracking directly west at the moment, i assume it will turn to the NW at some point as the models have suggested?

[summer blizzard]

It almost looks like they are trying to merge. That definitely would interfere with development.

I think that it is actually worse when they are next to each other, once they merge completely it will be like poring petrol on a bomfire.

I'd say the mass to the west looks in better shape than 91L at the moment. It seems to be tracking directly west at the moment, i assume it will turn to the NW at some point as the models have suggested?

NHC say the track is WNW however with the mass to the west absorbing 91L, the models may jump west.

[Somerset Squall]

I think that it is actually worse when they are next to each other, once they merge completely it will be like poring petrol on a bomfire.

The merger will disrupt development in the near term but after it's complete then yes, we are probably looking at a very large and potentially dangerous system.

[Iceberg]

Morning All.

Overnight we have lost the secondary feature to the west of Invest 91L, which was certaintly stopping the southern portion of circulation from 91L from tightening up.

A quick look at the 00Z initisations shows quite a bit of disagreement as to where the centre is and going from the atest NHC and satilite pictures none of them are accurate.

The 00Z initialisation of HWRF looks to be the best to be and has a south Florida hit again pretty close to Miami, the GFS re-curves it a little more and it should prevent landfall.

ECMWF has a very similar track to HWRF into Florida, but does not initialise it very well and never develops the system.

The path however has not been very consistant so everything is subject to a great deal of change.

Good convection seems to be around a centre(bit reluctant to say it's the centre or is an LLCC as this system seems to generate multiple vortices at will, which is certaintly slowly down initial development).

Recon should be in around lunchtime again, hopefully with more reliable equipment !.

Finally Dvorak has increased to T2.0 which is the highest it has been so far.

01/0545 UTC 14.4N 55.6W T2.0/2.0 91L

31/2345 UTC 14.3N 53.8W T1.5/1.5 91L

31/1745 UTC 13.1N 56.8W T1.5/1.5 91L

31/1145 UTC 13.2N 51.2W T1.0/1.0 91L

31/0545 UTC 12.8N 50.1W T1.0/1.0 91L

30/2345 UTC 12.6N 48.8W T1.0/1.0 91L

30/1745 UTC 12.8N 47.4W T1.0/1.0 91L

[Iceberg]

It seems to be concentrating around 15 56, with good outflow and certainly upper circulation. I've been wrong a few times but I think this is it now.

[Iceberg]

Surface winds of 30-35 kts are being recorded by recon currently in there, but no closed circulation yet or central low pressure, however recon might be struggling to find it.