ATL: IRMA - Post-Tropical - Discussion

[sma10]

Here is my beef with climatology. It is a useful tool, but just that; a tool. It is not absolute. Just because something is rare in cimo terms, does not mean that it will be extremely unlikely for this storm. Every storm, its steering patterns, etc, must be taken as an individual unit, with climo one of many considerations.

Strictly following climatology, your namesake should have gone out to sea.

[sma10]

So far, I've found a total of 6 storms that were 14.0N or further north when at 30W that went on to hit the Conus (all but Gloria hit as major hurricanes):

1. The storm of 1893, already mentioned, that was the only one N of 15N at 30W.

2. Storm #2 of 1915 was at 14.1N at 30W and hit TX:

http://weather.unisys.com/hurricane/atl ... /track.gif


3. Storm #6 of 1938, which was at 14.7N, 30W, also hit the CONUS (big one that hit NE US):

http://weather.unisys.com/hurricane/atl ... /track.gif


4. Storm 4 of 1947, which was at 14.3N, 30W, and hit FL:

http://weather.unisys.com/hurricane/atl ... /track.gif


5. Gloria of 1985, which grazed NC and then hit the NE US, was at 14.7N, 30W:

http://weather.unisys.com/hurricane/atl ... /track.gif


6. Fran of 1996 was at 14.1N, 30W, and hit NC:

http://weather.unisys.com/hurricane/atl ... /track.gif

The most interesting takeaway from this data is how it resulted in a cornucopia of solutions. Take that, climatology!

[KWT]

To have it clear about the "out to sea" words,if what one model has pans out,Bermuda would be in the crosshairs.Is better to say it recurves from the U.S.

Yeah a Bermuda hit is certainly an option and wouldn't make it a total fish either.

Just need to remember that typically the system ends up west of where the models intitally forecast and the ridging *tends* to be underdone in these set-ups. Expect a longer track on its W/WSW tracking before it curves up.

[Aric Dunn]

I can think of one storm that baffled models and forecasters a like that dove sw .. though ike made it much farther than irma will before it bends to the SW..

The patterns that exists with this type of set up often lead to threats to the islands and the mainland.

Ike was supposed to recurve pretty quick after it started moving SW but instead it kept moving SW and hit cuba...
let try and keep our speculation down to 3 days at a time, please..

right now anywhere from the central islands to texas and the NE are in play.. but lets just focus on the islands first..

Yeah Ike was just like this in many ways, long tracking CV storm that bent WSW.

Worth remembering Ike also was nearly at 25N when it bent WSW.

Katrina also went way more WSW than any models were predicting when it began its dive.

A key thing to watch for is how far north it moves before the turn.. if it stays more westerly the wsw to sw motion might be farther south. meaning both ridges the one sterring it now and the much stronger one near the islands end up being stronger.

also if this becomes a major hurricane while moving wsw to sw around that second ridge then we run the risk of it pumping up that ridge and keeping more of a WSW to W motion longer. similar to the what the EURO is doing .. especially the euro yesterday that drove it through the greater antilies.

[sma10]

I can think of one storm that baffled models and forecasters a like that dove sw .. though ike made it much farther than irma will before it bends to the SW..

The patterns that exists with this type of set up often lead to threats to the islands and the mainland.

Ike was supposed to recurve pretty quick after it started moving SW but instead it kept moving SW and hit cuba...
let try and keep our speculation down to 3 days at a time, please..

right now anywhere from the central islands to texas and the NE are in play.. but lets just focus on the islands first..

Yeah Ike was just like this in many ways, long tracking CV storm that bent WSW.

Worth remembering Ike also was nearly at 25N when it bent WSW.

Katrina also went way more WSW than any models were predicting when it began its dive.

A key thing to watch for is how far north it moves before the turn.. if it stays more westerly the wsw to sw motion might be farther south. meaning both ridges the one sterring it now and the much stronger one near the islands end up being stronger.

also if this becomes a major hurricane while moving wsw to sw around that second ridge then we run the risk of it pumping up that ridge and keeping more of a WSW to W motion longer. similar to the what the EURO is doing .. especially the euro yesterday that drove it through the greater antilies.

Also, a key difference will be the ridge orientation after the dip. All the models agree on the dip ... but the Euro and UK feel the developing Atlantic ridge will be flatter, while the GFS shows an angled ridge which supports a much earlier northward component of motion.

[Aric Dunn]

by the way.. latest visible showing a proto eye developing.. the deep convection has waned as is part of the process and you can see the convection building and wraping around in all quads.

[cycloneye]

Loop.

http://rammb.cira.colostate.edu/ramsdis ... display=12

[RL3AO]

I'll put the peak intensity over/under at 126 knots. I'd be surprised if we don't get a cat 4 out of this in 7 to 10 days.

[Hurricane Andrew]

I'll put the peak intensity over/under at 126 knots. I'd be surprised if we don't get another cat 4 out of this in 7 to 10 days.

Wonderful...another one. And, although it is a mere possibility at this point, one that may decide to pay a visit to yours truly. Luckily, any US landfall is still 10-14+ days out...so plenty of time for the steering patterns to become more favorable for a recurve.

[Ken711]

I'll put the peak intensity over/under at 126 knots. I'd be surprised if we don't get a cat 4 out of this in 7 to 10 days.

I agree. I'm thinking Matthew Cat 5 level.

[MGC]

Looks like Irma has excellent satellite presentation. If conditions are right this could be a significant tropical cyclone. Not liking the WSW tack in the central Atlantic, this could increase the threat to the islands and CONUS. The 1947 hurricane was the last to have an eye track directly over New Orleans. My Dad said it was pretty bad......MGC

[Michele B]

I'll put the peak intensity over/under at 126 knots. I'd be surprised if we don't get a cat 4 out of this in 7 to 10 days.

I agree. I'm thinking Matthew Cat 5 level.

You thinking "Matthew" for track, too, Ken??

[cycloneye]

Nice structure.

[Michele B]

So far, I've found a total of 6 storms that were 14.0N or further north when at 30W that went on to hit the Conus (all but Gloria hit as major hurricanes):

1. The storm of 1893, already mentioned, that was the only one N of 15N at 30W.

2. Storm #2 of 1915 was at 14.1N at 30W and hit TX:

http://weather.unisys.com/hurricane/atl ... /track.gif


3. Storm #6 of 1938, which was at 14.7N, 30W, also hit the CONUS (big one that hit NE US):

http://weather.unisys.com/hurricane/atl ... /track.gif


4. Storm 4 of 1947, which was at 14.3N, 30W, and hit FL:

http://weather.unisys.com/hurricane/atl ... /track.gif


5. Gloria of 1985, which grazed NC and then hit the NE US, was at 14.7N, 30W:

http://weather.unisys.com/hurricane/atl ... /track.gif


6. Fran of 1996 was at 14.1N, 30W, and hit NC:

http://weather.unisys.com/hurricane/atl ... /track.gif

The most interesting takeaway from this data is how it resulted in a cornucopia of solutions. Take that, climatology!

More proof we have a long way to go to understanding how and why these things move and develop the way they do!

[txwatcher91]

Looks good on satellite, most likely will become a hurricane within 24-36 hours as the SST's of 26C will be enough for a minimal cane along with the good UL environment. This one could easily become our first cat 5 of the year... question is where it goes long term. The "I" storms seem to have a tendency of being particularly nasty for whatever reason.

[gatorcane]

Looks like Irma has excellent satellite presentation. If conditions are right this could be a significant tropical cyclone. Not liking the WSW tack in the central Atlantic, this could increase the threat to the islands and CONUS. The 1947 hurricane was the last to have an eye track directly over New Orleans. My Dad said it was pretty bad......MGC

Yes, this one did have a WSW track in the MDR between Lesser Antilles and Africa. I was also thinking about this one as a possible analog but note it is more south in latitude than Irma already:

[tgenius]

Looks like Irma has excellent satellite presentation. If conditions are right this could be a significant tropical cyclone. Not liking the WSW tack in the central Atlantic, this could increase the threat to the islands and CONUS. The 1947 hurricane was the last to have an eye track directly over New Orleans. My Dad said it was pretty bad......MGC

Yes, this one did have a WSW track in the MDR between Lesser Antilles and Africa. I was also thinking about this one as a possible analog but note it is more south in latitude than Irma already:

I've always wondered how accurate those tracks are since we didn't have satellite at that point?

[beoumont]

Blinhart opined "I'm sorry to disagree with you, with what the models are showing, they are letting people know ahead of time that they need to be vigilant and not be caught by surprise."

"Cry Wolf Syndrome" is an important factor that the real hurricane forecasters, the ones that bear the weight of responsibility (NHC guys) are very cognisant of. They would never state, based on 12+ day computer progs that "all residents of the east coast" should pay close attention to future advisories of Hurricane Ziggy". Five days out they might start to do this; and the 5-day cone implies this strongly when portions of it reaches a coastline.

Forecasters with the weight of, or the feeling of responsibility, make it clear repeatedly, that anytime during the hurricane season, especially the heart of the season, that the public should be vigilant of every tropical entity.

When they, as the commercial weather guy has done, overly raise anxieties time after time, and the 12 day out "threat" does not materialize, the Cry Wolf Syndrome sets in. THEN when a hurricane warning is actually issued for a true threat, a higher % of the public does not take heed. One example being the people who drowned, or almost drowned during IKE, that stayed on those barrier islands east of Galveston.

When a true threat occurs, 3 days out or less, then it is responsible to state (as Neil Frank did), "There really is a wolf out there!"

Anyways, or course you have a right to disagree; that's what de bait is all about. And since your post, the GFS, that had Irma crossing the Florida Keys, has shifted eastward, then further eastward to near Bermuda. But, of course, as usually happens over time, the forecast track will shift back west again.

[KWT]

Wonderful structure cycloneye.

There is some drier air to the north of this system which may limit the convective ability of this storm over the next day but the structure is there for it to become a hurricane pretty quickly.

Anyway as expected, still rolling near due west.

[marionstorm]

Glad the models are showing it as a fish storm. Why do people think it could be a category 5 storm?