ATL: IGOR - Ex Hurricane - Discussion

[Ivanhater]

After Igor, the 00Z gfs is suggesting a pattern change with consistent ridging off the East coast.

[South Texas Storms]

so when should activity start to move from the cape verde storms to the caribbean? after igor, or towards the end of the month?

[hurricaneCW]

The difference between the Euro and the gfs is that the Euro indicates a change in the pattern with more ridging faster than the gfs shows. Then again, both of the models could be showing off their biases with the troughiness of the gfs and the stronger ridging of the Euro.

[canes101]

After Igor, the 00Z gfs is suggesting a pattern change with consistent ridging off the East coast.

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[img]http://raleighwx.easternuswx.com/models/gfs/00zgfs500mbHGHTPMSLtropical384.gif[/img]

So what does that mean Ivanhater?

[Ivanhater]

The Euro was showing this pattern change as well, just earlier.

Pretty much, anything after Igor has a shot of continuing west without a trough waiting to pick it up. The ridge consistently holds off the east coast and not breaking down. This change has been expected for a while, but now starting to come into the picture starting the 2nd half of September.

[Wx_Warrior]

That's Sept. 26 too...getting close to Oct....

[hurricaneCW]

Well the question will be, will the pattern change actually occur? How will Igor be affected by it? Will the change happen before, during, or after Igor? Even if Igor recurves, future Cape Verde systems probably won't if the ridging is correct.

According to the gfs, the Cape Verde systems will continue to be alive and well all the way to late September so if the pattern change occurs and we have a Cape Verde system, then you can bet it's coming all the way to the U.S. or very close to it.

[Ivanhater]

That's Sept. 26 too...getting close to Oct....

The pattern change occurs well before the end of the run I posted, it occurs right after Igor. The Euro suggests during Igor. This is a La Nina season, October will probably look a lot like September out there...

[canes101]

Thank you for the explanation Ivanhater. It is much appreciated

[stormhunter7]

http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
330 PM EDT THU SEP 09 2010


THE NEW 12Z GFS DEVELOPS A SOMEWHAT
RETROGRESSIVE LOOK TO IT DAYS 6-7 AS IT AMPLIFIES A STRONG SYS
NEAR 45N/145W. IN THIS REGARD...IT IS CONSISTENT WITH ITS 00Z/09
RUN AND FINDS SUPPORT EVEN FROM THE OTHERWISE ERRATIC CANADIAN
MODEL.

A PATTERN CHANGE IN THE WIND? PERHAPS. A DEVELOPING DOMINANT
NEGATIVE HEIGHT ANOMALY NEAR 45M/145W SUPPORTS A WRN NOAM RIDGE
AND TROF ALONG 80W. THE NEW 12Z ECMWF IS TRENDING TOWARDS THE
CORRESPONDING GFS WITH THE DETAILS OF THE ERN PACIFIC TROF DAYS
6-7. THAT BEING SAID..THE NEW ECMWF HAS MUDDIED THE WATERS FARTHER
E...KEEPING MUCH HIGHER HEIGHTS OVER THE E COAST STATES DAYS 5-7.
IT SEEMS TO BE GOING TO THE OPPOSITE EXTREME OF THE 00Z GFS. IT IS
IN OPPOSITION TO TELECONNECTIONS ON THE ERN PACIFIC TROF. FOR NOW
WE REJECT THE NEW ECMWF OVER THE ERN CONUS DAYS 5-7. WE FAVOR OF
KEEPING SOME KIND OF BROAD NOT TOO DEEP TROF OVER THE NERN CONUS
DAYS 5-7.

[abajan]

That's Sept. 26 too...getting close to Oct....

The pattern change occurs well before the end of the run I posted, it occurs right after Igor. The Euro suggests during Igor. This is a La Nina season, October will probably look a lot like September out there...

Yep. Today may be the peak climatologically speaking but the real activity may well occur later this month or even in early October.

[O Town]

Looking like development is coming right along. Nice outflow this morning.

[KWT]

Igor looking like a TS again now, I'd go upto 40kts now, whilst the circulation is a little on the eastern side of the system it still looks pretty good and no doubt its convection is strong right now.

Looks like all systems go for Igor, see no reason why it can't be a major down the line...

ps, it has a *huge* circulation gyre, this could be a large hurricane, maybe even very large if it undergoes enough EWRC down the line.

[Macrocane]

Looking a the latest visible the center is under the convection on the eastern side as KWT said but under the convection, I see no reason to keep it as a TD on the next advisory.

[HURAKAN]

very strong vorticity

[HURAKAN]

strong convection developing over the center

[cycloneye]

12z Best Track

AL, 11, 2010091012, , BEST, 0, 163N, 303W, 35, 1004, TS

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 010.invest

Back to Tropical Storm.

[Wx_Warrior]

JB's talks have been most about Igor. Glad it's back to TS. He was about to blow a gasket! LOL

[HURAKAN]

Latest

[HURAKAN]

latest visible