ATL : TROPICAL DEPRESSION ERIKA (06L)

[KWT]

What I will say is if this does stay weak (well no higher then low TS strength) before 50W then this could be one to watch possibly...we shall see there is supposed to be a weakness present that will lift up 94L but whether its enough to actually drag it as far north as progged who knows.

Remember the models don't handle systems without a defined circulation all that well sometimes even if its got a vort max to track, and also are poor with upper level features, both which may not be very well resolved in this case!

[Derek Ortt]

this looks to be in as bad of shape as does Danny! Convection is 150NM from the area of greatest vorticity

wont see development as long as this persists

[Derek Ortt]

What I will say is if this does stay weak (well no higher then low TS strength) before 50W then this could be one to watch possibly...we shall see there is supposed to be a weakness present that will lift up 94L but whether its enough to actually drag it as far north as progged who knows.

Remember the models don't handle systems without a defined circulation all that well sometimes even if its got a vort max to track, and also are poor with upper level features, both which may not be very well resolved in this case!

dynamical models do not need a center, unless there are moving nests. And then, it is FORTRAN not meteorological constraint

[cycloneye]

As Derek said,circulation is in the back end of convection as easterly shear is impacting it.

[KWT]

Oh I know Derek that why I mentioned the Vort max part as well...
When I mean circulation I also mean the way it handles the strength of it and how they can be too agressive in development.

[KWT]

this looks to be in as bad of shape as does Danny! Convection is 150NM from the area of greatest vorticity

wont see development as long as this persists

Also seems like the circulation is gaining latitude at a decent rate as well?
Could we see it try and re-locate itself towards the convection over time?

[cycloneye]

The 18 UTC surface analysis from TAFB adds a surface low (1009 mbs) to wave axis.

[StormTracker]

[cycloneye]

Finnally,we can follow more closely 94L as floater is up.

[RL3AO]

What is it about the current conditions this year causeing all these storms to recurve, not that I am complaining. Also does anyone think the storm still in Africa could do anything? thanks

Theres been constant troughs over the Eastern US/Canada.

Its also the reason for the northeast and midwest cooler summer.

[cycloneye]

ABNT20 KNHC 272338
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT THU AUG 27 2009

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

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM DANNY...LOCATED ABOUT 515 MILES SOUTH-SOUTHEAST OF CAPE
HATTERAS NORTH CAROLINA.

AN AREA OF DISTURBED WEATHER ASSOCIATED WITH A TROPICAL WAVE IS
LOCATED OVER THE FAR EASTERN ATLANTIC OCEAN ABOUT 450 MILES
SOUTHWEST OF THE CAPE VERDE ISLANDS. THIS SYSTEM CONTINUES TO SHOW
SIGNS OF ORGANIZATION...AND SLOW DEVELOPMENT IS POSSIBLE OVER THE
NEXT COUPLE OF DAYS AS IT MOVES WESTWARD AT 10 TO 15 MPH. THERE IS
A MEDIUM CHANCE...30 TO 50 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

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

$$
FORECASTER PASCH

[Blown Away]

The TPC has 94L moving just N of due W through 72 hours. No sign of recurve for at least 72 hours.

[KWT]

I have to agree with Derek right now this system doesn't look that impressive, sure its flaring a heap of convection but its lop-sided still, any circulation is going to have a tough time getting going in that sort of set-up.

Also BA, thats very interesting, the longer this one stays weak the less its going to feel those upper level weaknesses, somewhat like we saw with Ana FWIW.

[otowntiger]

Yep, and quite possibly like we saw with Ana, this one may not develop either. There's probably a reason that several models aren't doing much with it.

[KWT]

The easterly shear could well be one such reason, still I wouldn't want a system getting past 60W with the Bermuda high at least briefly strengthening, we shall see what happens in that respect, timing is going to be everything if this has a shot at making it across, recurve has to be about 80-90% likely based on the pattern progged, though of course the longer it stays weak in this situation the less the chance becomes IMO.

[cycloneye]

18z GFDL

More west than the 12z run.

ATTENTION...NATIONAL HURRICANE CENTER



NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR



TROPICAL DEPRESSION INVEST 94L



INITIAL TIME 18Z AUG 27



DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT

REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD

NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC

OFFICIAL FORECAST.





FORECAST STORM POSITION



HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)



0 10.9 27.0 270./14.0

6 11.5 28.8 289./19.1

12 11.8 30.6 277./17.3

18 10.1 31.6 213./19.4

24 11.3 32.1 337./12.3

30 11.9 34.4 286./23.1

36 12.4 35.9 286./15.6

42 12.7 37.4 282./14.9

48 13.1 38.7 289./13.2

54 13.9 39.9 301./14.1

60 14.3 41.3 287./14.4

66 14.7 42.7 287./13.5

72 15.3 43.9 296./13.1

78 15.6 45.1 283./11.9

84 16.0 46.0 295./ 9.7

90 16.6 46.6 312./ 8.4

96 17.1 47.7 296./11.7

102 17.3 48.6 284./ 9.1

108 17.3 49.6 270./ 9.0

114 17.7 50.2 297./ 7.0

120 17.9 51.2 285./ 9.7

126 18.2 52.1 290./ 8.8


12z last position=19.0N-45.2W
18z last position=18.2N-52.1W

[otowntiger]

this looks to be in as bad of shape as does Danny! Convection is 150NM from the area of greatest vorticity

wont see development as long as this persists

What is your prediction on this one Derek? What if anything do you expect of it? I realize you don't officially post predictions until it is classified as a TC, but just like to get your thoughts preliminarily.

[KWT]

Yep it is further west, still pretty far north though at 50W for it to be a real threat to the US unless a big high develops...remember between 144-192hrs there appears to be a big weakness around 60-70W which would probably lift out 94L a lot if it gets there around that time, probably enough for a total recurve if its there at that time.

[cycloneye]

Here is the animation of this 18z GFDL run.

http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation

[cycloneye]

18z HWRF continues to be pure fish.

http://moe.met.fsu.edu/cgi-bin/hwrftc2. ... =Animation