ATL: IGOR - Ex Hurricane - Discussion

[Annie Oakley]

Beautiful images

[TheBurn]

[TheBurn]

[TreasureIslandFLGal]

this looks liek it has the potential to be a very large sized storm. hopefully it stays away from all land, including Bermuda.

[cycloneye]

5 PM Forecast Track. Forecast to become a major cane.

[RL3AO]

I suspect we'll be looking at our 3rd cat 4 of the season here next week.

[KWT]

Yeah I think this almost certainly will be another major hurricane, conditions look good for it down the line.

This looks like being a very long lasting system as well by the way, don't expect this one to be gone before the 20th September IMO...going to rake up some very big ACE...

[Migle]

Really nice looking system. Hopefully this continues to grow and racks up some numbers while staying away from land. 3 Majors in 3 weeks that all started at pretty much at the same place is interesting.

[abajan]

Yesterday at 5 pm, this is where Igor's center was forecast to be by 2 pm on Tuesday:




Today at 5 pm EDT, this is where its center is expected to be by 2 pm on Wednesday:



Were I living in the Leeward Islands, I would be a bit concerned, especially knowing that Igor is now forecast to become a large and major cane with maximum sustained winds of 105 knots (120 mph).

The preceding post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For Official Information please refer to the NHC and NWS products.

[KWT]

Yeah the track has shifted westwards, a similar thing happened with Earl as well and whilst there is a weakness there its not the clear cut out to sea type set-up IMO, instead all any weakness may do is lift this to the north and therefore clearly it got west of 60-65W it'd need very close watching indeed...

[blazess556]

There is absolutely no way igor is only a 45 mph ts. hes probably pushing 65-70.

[cycloneye]

There is absolutely no way igor is only a 45 mph ts. hes probably pushing 65-70.

Stacey Stewart talks about that at 5 PM discussion.

THE INITIAL INTENSITY HAS BEEN
CONSERVATIVELY INCREASED TO 40 KT...WHICH WILL BE TOO LOW IF THE
LOW-LEVEL CENTER IS ACTUALLY CLOSER TO THE DEEP CONVECTION.

[CrazyC83]

The question mark is if the center indeed is in the deep convection. It would help a lot if we had Recon out there.

[JTD]

Stacey Stewart is always known for his fascinating and in-depth discussions. He's at it again. I just want to point out 2 particular snippets from his 5 pm discussion that I found very interesting:

THE INITIAL MOTION IS 280/18. THERE IS NO CHANGE TO THE PREVIOUS
TRACK FORECAST OR REASONING. IGOR IS EXPECTED TO MOVE WESTWARD...
ACCOMPANIED BY A GRADUAL DECREASE IN FORWARD SPEED...FOR THE NEXT 96
HOURS AS THE CYCLONE MOVES ALONG THE SOUTHERN PERIPHERY OF A LARGE
AND STRONG SUBTROPICAL RIDGE SITUATED TO THE NORTH. BY DAY 5...A
BROAD LONGWAVE TROUGH IS FORECAST TO MOVE OFF THE U.S. EAST COAST
AND CREATE A WEAKNESS IN THE RIDGE TO THE NORTHEAST OF THE LESSER
ANTILLES. THIS SHOULD CAUSE THE STEERING FLOW TO WEAKEN AND ALLOW
WHAT IS EXPECTED TO BE A LARGE HURRICANE IGOR AT THAT TIME TO
GRADUALLY TURN WEST-NORTHWESTWARD. THE LATEST MODEL GUIDANCE IS
MORE TIGHTLY PACKED AROUND THE PREVIOUS NHC TRACK...ESPECIALLY AT
DAYS 4 AND 5. IN PARTICULAR...THE GFDL AND ECMWF SHOW LESS OF A
NORTHWARD TURN THAT MIGHT BE RELATED TO A FLATTER LONGWAVE TROUGH
IN THE LATEST GLOBAL RUNS. THE OFFICIAL FORECAST TRACK REQUIRES
LITTLE CHANGE AND IS AN EXTENSION OF THE PREVIOUS ADVISORY.

Note that he says gradually turn WNW. Not NW/NNW/NE. Interesting. Also note that there is a flatter longwave trough. That's something to pay attention to as has been mentioned by others on this board as well I believe.

Also, the intensity forecast from the NHC is startling. They rarely are this aggressive with tropical storms.

Another snippet from them:

THIS FAVORABLE UPPER-LEVEL ENVIRONMENT...IN
CONJUNCTION WITH SSTS INCREASING TO 29C BY THE END OF THE FORECAST
PERIOD...SHOULD RESULT IN STEADY INTENSIFICATION. IGOR IS EXPECTED
TO REACH HURRICANE STATUS BY SUNDAY AND MAJOR HURRICANE STATUS BY
DAYS 4 OR 5. THIS SCENARIO IS SUPPORTED BY THE SHIPS...LGEM...
HWRF...AND GFDL MODELS.



FORECAST POSITIONS AND MAX WINDS

INITIAL 10/2100Z 16.7N 33.3W 40 KT
12HR VT 11/0600Z 16.8N 35.4W 45 KT
24HR VT 11/1800Z 17.1N 38.4W 50 KT
36HR VT 12/0600Z 17.2N 41.0W 60 KT
48HR VT 12/1800Z 17.3N 43.4W 70 KT
72HR VT 13/1800Z 17.7N 47.8W 80 KT
96HR VT 14/1800Z 18.7N 51.6W 90 KT
120HR VT 15/1800Z 20.0N 55.0W 105 KT

Note just how much model support that there is towards making this a very strong hurricane. It's disturbing to have 3 category 4's in what 2/3 weeks in the basin, which Igor would be if it makes it to that status.

I would venture to say that this is definitely a threat to Bermuda now and perhaps points further west but the evidence is inconclusive on that. It doesn't look quite as clear-cut to me now as it did a few days ago that this would turn conclusively out to sea.

I highly recommend this fascinating discussion from the NHC and the link is here:
http://www.nhc.noaa.gov/text/refresh/MI ... 2044.shtml

[Aquawind]

Only one storm in recorded history has reached the U.S. from Igor's current location (within 1 deg radius). That was the August 1893 hurricane that hit Savannah, GA. No storm struck the Caribbean from so far north. Odds of Igor striking land are very low. Most recurve well east of Bermuda, too. So Igor will most likely pass northeast of the Caribbean. And very likely, Igor will recurve east of Bermuda. But I'm not ready to 100% rule out an East U.S. Coast threat. Just about 98%.

Nice.. I like those odds even though the 2% does happen..we be watching either way..

[CrazyC83]

Note just how much model support that there is towards making this a very strong hurricane. It's disturbing to have 3 category 4's in what 2/3 weeks in the basin.

You mean 4 of them if 92L lives up to its full potential?

[KWT]

I wouldn't be at all surprised to see this be as high as 50-55kts right now to be honest, I suspect the center is close to the center of the deep convection right now.

[wxman57]

NHC has the center on the very eastern edge of the circular area of convection, thus the lower wind. Looks to me like the center may be a little west of there now, but I don't think it's near the center of convection. But shear is relaxing, and the center should tuck underneath tomorrow.

[Aquawind]

That is some deep and persistant convection..conservative at 40kt alright..it is in no mans land so no big deal either way..

http://www.ssd.noaa.gov/goes/flt/t1/flash-bd.html

[cycloneye]

I agree with KWT.