Hurricane Helene,Analysis,Sat Pics,Models Thread

[Meso]

As far as I know it was a joke... :S

[Thunder44]

I believe that is why he said negatively tilted as it would have the opposite effect

No, it would really bring the storm closer to the coast. Classic scenerio negtive-tilted trough would always mean an a storm coming up the coast in the winter time. It's what the 6z GFS does.

[wxman57]

http://www.sfwmd.gov/org/omd/ops/weather/plots/storm_08.gif

Hrm... Not drawing any conclusion from this,just showing the facts.. New model runs at 12z ... lots have shifted west,all the bams and the lbar,not very reliable.. just saying what they did. Just to clear up that I`m not going on about any EC threat.

Careful what you're looking at on that model plot. Those west-shifting "models" are mostly from climatology "models". There hasn't been any perceptible shift in 12Z dynamic models. All are tightly clustered on recurvature between 57W-58W. NOGAPS continues to indicate recurvature a little more to the west, btween 59-60W:

[BreinLa]

Why is the titled called Hurricane Helene. When did that happen?

[wxman57]

Why is the titled called Hurricane Helene. When did that happen?

New model data has the heading "Hurricane Helene". That's a sure sign the NHC is upgrading Helene to a hurricane on the next advisory.

[storms in NC]

http://manati.orbit.nesdis.noaa.gov/sto ... _at_2.html

[cycloneye]

Also Bre,the dvorak T number is 4.0 meaning is a hurricane at the advisory comming up in a few minutes.

[BreinLa]

I just thought we waited for the adevisory before we changed the title and I didn't see it in the last advisory.

[trugunz]

after 48 hours they spread out

[WeatherTracker]

latest model tracks...the GFDL seems like the most accurate track.

[WeatherTracker]

can anyone see an eye? there looks like there are 2 holes but I cannot tell which is the center.

[wjs3]

Also Bre,the dvorak T number is 4.0 meaning is a hurricane at the advisory comming up in a few minutes.

Hi, Cycloneye:

Just want to point out that a T number is no guarantee of an upgrade. In fact there was Dvorak estimate of 4.0 at 5 AM--from the discussion:

EVEN THOUGH DVORAK T-NUMBERS REMAIN AT 4.0
USING AN EMBEDDED CENTER PATTERN...CORRESPONDING TO AN INTENSITY OF
65 KT...THE PERCOLATING BEHAVIOR OF THE CONVECTION LEADS ME TO
LEAVE THE ADVISORY INTENSITY AT 60 KT FOR NOW


Best!

[Brent]

For the record, NRL has it at 65 kt and 987 mb.

[WeatherTracker]

For the record, NRL has it at 65 kt and 987 mb.

can you provide a link please?

[WmE]

For the record, NRL has it at 65 kt and 987 mb.

can you provide a link please?

http://www.nrlmry.navy.mil/tc-bin/tc_home2.cgi

[WeatherTracker]

For the record, NRL has it at 65 kt and 987 mb.

can you provide a link please?

http://www.nrlmry.navy.mil/tc-bin/tc_home2.cgi

thank you, I think they will upgrade helene at 11

[WmE]

For the record, NRL has it at 65 kt and 987 mb.

can you provide a link please?

http://www.nrlmry.navy.mil/tc-bin/tc_home2.cgi

thank you, I think they will upgrade helene at 11

No problem!

[WeatherTracker]

adviosry is coming out later than usual.....

[WeatherTracker]

Hurricane Helene Discussion Number 17

Statement as of 11:00 am EDT on September 16, 2006



geostationary satellite imagery indicates increasing organization of
Helene with robust banding convection on the north and west
quadrants...and a ragged eye attempting to form as seen in the
visible imagery. Moreover...SSMI and AMSU passes show a nearly
complete eyewall. Based upon consensus of Dvorak estimates...the
system is upgraded to a 65 kt hurricane. While a Saharan air-layer
is seen to the north and west of Helene in CIMSS imagery...total
precipitable water analyses from CIRA suggest that the dry air
remains at least a couple hundred miles from the center of the
system. Continued slow intensification is suggested over the next
three days due to 27.5 c SSTs...light/moderate vertical shear...and
a moist environment. At days 4 and 5...the SSTs warm up...but
shear increases may mitigate further intensification. A plateauing
of the intensity is called for around 72 hrs with slight weakening
thereafter. The intensity forecast is a blend of the SHIPS...FSU
super-ensemble...and GFDL models...which is slightly weaker than
previously predicted at the long-leads.
Current motion estimate is 305/12. Helene is on the southwest side
of a deep-layer ridge and is headed toward a break in the ridge...
which is partially being produced by Hurricane Gordon. All
reliable guidance is in close agreement with a continued movement
along this heading through 72 hr. At days 4 and 5...there is a
significant model divergence with the UK...GFDL...ECMWF being
faster and off to the north and the GFS and GFS ensemble slower and
off to the south. These differences are being driven by the
amplitude of the short-wave trough that will be pushing off of the
US East Coast at that time. The NOGAPS and consensus models are in
between these possibilities. The track forecast is close to the
consensus models and slightly slower and to the right of the
previous prediction.

A G-IV aircraft research mission is currently enroute to Sample
Helene's environment as part of noaa's salex Experiment.
Forecast positions and Max winds

initial 16/1500z 18.8n 45.6w 65 kt
12hr VT 17/0000z 19.5n 46.9w 70 kt
24hr VT 17/1200z 20.4n 48.3w 75 kt
36hr VT 18/0000z 21.1n 49.4w 80 kt
48hr VT 18/1200z 21.9n 50.6w 85 kt
72hr VT 19/1200z 23.5n 53.5w 90 kt
96hr VT 20/1200z 25.5n 56.5w 85 kt
120hr VT 21/1200z 28.5n 58.0w 80 kt

[Evil Jeremy]

steve lions says its a hurricane.