Hurricane Helene - Cat. 3

[superfly]

Huge burst of convection this morning



QS shows a broad circulation with 40kts winds on the southern side.

[HURAKAN]

Tropical Weather Outlook

Statement as of 5:30 am EDT on September 12, 2006

For the North Atlantic...Caribbean Sea and the Gulf of Mexico...
The National Hurricane Center is issuing advisories on Hurricane
Florence...located about 810 miles southwest of Cape Race
newfoundand...and on Tropical Storm Gordon...located about 445
miles north-northeast of the Leeward Islands.

A broad area of low pressure associated with a tropical wave is
centered near the coast of Africa about 250 miles southeast of the
Cape Verde Islands. This system is showing signs of organization
and has the potential to become a tropical depression over the next
day or so as it moves westward over the far eastern tropical
Atlantic.

Elsewhere...tropical storm formation is not expected through
Wednesday.

Forecaster Franklin

[TheEuropean]

INVEST 94L now:



NRL with 25kts and 1008 mb.

[HURAKAN]

TD 8 is very close (in time, not distance!!!!)

[quandary]

Between the convection and the 40kt vectors, does Quikscat show enough of a closed low to merit an upgrade to TD or TS status soon? I'd like to see this get as strong as possible as fast as possible so to start curving out to sea.

[Thunder44]

Huge burst of convection this morning

QS shows a broad circulation with 40kts winds on the southern side.

The purple barb (40kt) is surround by alot of black barbs, which means it could possibly be rain contaminated as well.

[HURAKAN]

It much better than Debby looked in its whole life.

[HURAKAN]

SPECIAL FEATURE .....

A STRONG TROPICAL WAVE IS LOCATED JUST OFF THE COAST OF AFRICA
ALONG 17W/18W S OF 18N. A 1009 MB LOW PRES SYSTEM IS ALONG THE
WAVE NEAR 12N. THIS SYSTEM IS FAIRLY LARGE WITH ITS BROAD
CYCLONIC ROTATION COVERING AN AREA OF A FEW HUNDRED NM. SHOWER
ACTIVITY WAS GENERALLY ON THE DECREASE THIS EVENING...HOWEVER
SCATTERED MODERATE CONVECTION HAS FIRED OVER THE LAST FEW HOURS
TO THE W OF THE ANALYZED SFC LOW FROM 10N-14N BETWEEN 20W-22W.
THIS SYSTEM HAS THE POTENTIAL TO DEVELOP DURING THE NEXT DAY OR
TWO AS IT MOVES WESTWARD 10-15 KT.

[WindRunner]

So, the quikscat is now from about 0700Z, and there is a uncontaminated 40kt vector (a west one at that), and there are 4 50kt vectors and 1 55kt vector. Of course, you can't tell if anything 50kts or higher is contaminated because they display as black anyway. There is also a tiny area of winds appx. 4 barbs or so due SE of the CVI that could qualify as enough of an east wind to call it a circulation. I am almost certain that an upgrade will go straight to TS status, and that upgrade could occur at 11am.

[HURAKAN]

TD 8 is very close (in time, not distance!!!!)

Helene is very close (in time, not distance!!!)

[HURAKAN]

So, the quikscat is now from about 0700Z, and there is a uncontaminated 40kt vector (a west one at that), and there are 4 50kt vectors and 1 55kt vector. Of course, you can't tell if anything 50kts or higher is contaminated because they display as black anyway. There is also a tiny area of winds appx. 4 barbs or so due SE of the CVI that could qualify as enough of an east wind to call it a circulation. I am almost certain that an upgrade will go straight to TS status, and that upgrade could occur at 11am.

It will be very interesting to see the 8 AM TWD.

[Normandy]

This, not Gordon, looks to be our first major....

and it looks like it might not recurve very fast....check out WXMan57's graphics in the TS Gordon thread, it shows a strong ridge right over it and the western extent is near the eastern Caribbean Islands.


But for right now it does not look that well organized if that QS is correct....it shows the center of the circulation well N of the deepest convection.

[wxman57]

Even though it may track west for a while, the GFS still forecasts a sharp trof around 55-60W by the time 94L (Helene shortly) reaches that longitude. That would mean a track similar to Gordon's, perhaps even east of Gordon. Too far out to be very sure, though.

[Thatsmrhurricane]

I just noticed the same thing. CMC, GFS, and NOGAPS, curve 94 out to sea before 60W.

http://www.meteo.psu.edu/~gadomski/ewalltropatl.html

[HURAKAN]

Getting a more spiral look!!!

[senorpepr]

MET-8 MSI Image, courtesy to AFWA:

[Robjohn53]

This thing will be intresting to watch. Just have to see what it dose.

[weatherwindow]

just taking a look at the globals...it appears that the combination of the east coast troughing and the impacts of flo and gordon will have left the atlantic ridge in pretty sad shape.....earlier posts were alluding to a rebuilding, somewhat contiguous ridging in the latter half of september....there is no evidence of a tendency toward that result in any of the current model runs(out to 144hrs)...the current weakness from the east coast east to 60deg W, if anything, amplifies as the central atlantic ridging retreats further east and, as 94L develops and moves west, forces recurvature east and north of the islands.....IMO, as the cv season moves to its conclusion, only very low latitude sytems(forming S of 12degN) will have a reasonable probability of reaching the caribbean, gom or the east coast...as boca mentioned, barring an unforeseen change in the synoptics in the central/western atlantic, our focus will soon shift to the western caribbean for us landfall threats

....as far as an ultimate island/us threat, it may be instructive to contrast the model runs and synoptic setup of 94L with the tropical cylone products archive at the nhc site on hurricane georges 1998....note in particular, genesis at 9degN and the subsequent advisory discussions with a focus on the nhc evaluation of the subtropical ridge in place at that time....in general, the difference in ridge strength, continurity and placement is pretty stark and puts this year in perspective... for the uninitiated, georges was a late season long-track cv system which eventually landfell pr, hispaniola, cuba, the florida keys and ms during the last week of sept, 1998...what a difference in synoptics!..........rich

[HURAKAN]

805 AM EDT TWD:

A STRONG TROPICAL WAVE IS LOCATED OFF THE COAST OF AFRICA ALONG
20W/21W S OF 19N. A 1008 MB LOW PRES SYSTEM IS ALONG THE WAVE
NEAR 13N. THIS SYSTEM IS FAIRLY LARGE WITH ITS BROAD CYCLONIC
ROTATION COVERING AN AREA OF AT LEAST A FEW HUNDRED NM. SHOWER
ACTIVITY WAS GENERALLY ON THE DECREASE LAST EVENING...HOWEVER
SCATTERED MODERATE TO STRONG CONVECTION HAS FIRED AND EXPANDED
SIGNIFICANTLY OVER THE LAST SEVERAL HOURS TO THE SOUTH AND WEST
OF THE ANALYZED SFC LOW FROM 9N-15N BETWEEN 19W-25W. A QUIKSCAT
PASS NEAR 0700 UTC SHOWED GUSTY WINDS S OF THE LOW. IT WAS ALSO
HELPFUL IN LOCATING THE LOW CENTER WHICH WAS ADJUSTED TO THE NW
FROM THE 00 UTC MAP. THIS SYSTEM IS SHOWING SIGNS OF
ORGANIZATION AND HAS THE POTENTIAL TO BECOME A TROPICAL
DEPRESSION OVER THE NEXT DAY OR SO AS IT MOVES WESTWARD 10 TO 15
KT.

[Hyperstorm]

This system is well on its way to being classified Tropical Storm Helene later today. Satellite imagery reveals very deep thunderstorm activity developed (nocturnal maxima) near, but mostly south and west of a circulation center near 13N. From satellite, the system already seems to be at least a 2.0 in Dvorak intensity estimates. I don't know what is the maximum that is allowed on a first-time estimate, but wouldn't be surprised to see a 2.0 estimate this morning. If not, definitely a 1.5.

There is not much to impede this system to continue strengthening strongly over the next few days with light shear values, associated with a westward moving ULL in the central Atlantic. SAL is not looking like a problem for this one with the explosive convection this morning as proof.

The track looks to take a more WNW-NW course after about 4 days, due to that ULL in the central Atlantic remaining stationary or possibly drop southward by the time the system reaches the area. Still way too early to tell for sure, though and would caution residents in the Lesser Antilles to start monitoring its progress. Conditions appear to favor a dangerous and powerful hurricane in several days.

I remember mentioning 2001 earlier with some of the "season cancel" posts ongoing. This one is following that year and we're not even done with September yet. Proves that we can't raise the "end" flag before September as is very common for the Atlantic basin to have very late seasons.

Who said season cancel?