Hurricane Irma

[knocker]

21 minutes ago, Iceberg said:

Purely of interest as the path will change but the ec moves the upper trough away more quickly Hence less interaction with Irma and therefore a position further west and south. 

This looks like a direct Nassau hit to me a sub 920 cat 5. 

 

Yes indeed and much depends on how this highly amplified pattern pans out. As you say at T144 the trough is on the move NE where the blocking ridge resides, Another ridge quickly becomes the order of the day and all of this conspires to keep Irma on a very dangerous track. Fortunately there is plenty of time for some major changes.

Edited September 2, 2017 by knocker

[Iceberg]

Yes lots of time for changes in nearly all the variables. It's difficult to see any of the changes giving a realistic chance for Irma to escape landfall somewhere which is worrying. I see little evidence that the trough will hang around long enough and deeply enough to pick Irma up and throw her towards Newfoundland. 

Gfs is always overly deep with troughs in the 200+ timeframe even for us !

i know a few folks might wonder how we can talk about cat 5 etc. Normally I wouldn't dream of forecasting a cat 5 7 days out. However every single model run from gfs and ec recently has pressure sub 920mb in the last 20 years there hasn't been a sub 920 that wasn't a cat 5. TBH anything below 925mb could assumed to be a cat 5 given Irmas likely size. But certainly less than 920mb. 

[summer blizzard]

Despite you all getting giddy this morning i think it has to be remembered that we are still ten days from landfall and one only has to remember Joaquin 15 to recall how until a few days out we were sure of a hit. 

I retain my prior belief..

10% chance of a hit in Florida/Cuba

45% out to sea/Newfoundland at best

45% Hatteras (a few hundred miles either side)

..

I will note that from our own model watching i suspect that the GFS will in reality have a slower and more amplified pattern so back the trough west a bit and make it a bit more negatively tilted. In that context a hit onto the south east facing coast like the Euro actually seems a stronger possibility. 

Anecdotally the Carolina's are also strongly overdue.

Edited September 2, 2017 by summer blizzard

[knocker]

 

[Iceberg]

I get your point sb. It's just difficult to see the trough picking her up early enough to get the recurve. 

Gfs 06z is very similar to the 00z and has a cat 4/5 hit on New Jersey. With surge maximum funnelling into ny city so more flooded metro stations. 

Personally I think it will be south of that point though. 

Currently Irma is entering the slightly warmer ssts and should start to expand a bit. The cdo is showing signs of this and t numbers are back on the increase again. 

[Zephyr]

Slight SW movement maybe? And they eye starting to clear back out

[summer blizzard]

5 minutes ago, Iceberg said:

I get your point sb. It's just difficult to see the trough picking her up early enough to get the recurve. 

Gfs 06z is very similar to the 00z and has a cat 4/5 hit on New Jersey. With surge maximum funnelling into ny city so more flooded metro stations. 

Personally I think it will be south of that point though. 

Currently Irma is entering the slightly warmer ssts and should start to expand a bit. The cdo is showing signs of this and t numbers are back on the increase again. 

Indeed, if we are going from current modelling then even on the Euro it's more like 80/20 on the ensembles (GEFS has a 100% hit rate). I'm generally suspicious at this range though and climatology is strongly in favour of a recurve so i give it a lot of credense, not least since we know that shortwaves don't get picked up until close range and we still don't know for certain whether we are dealing with a cut-off low (in which case i go back to my thinking that the actually pattern will be more amplified and further west) - something that strongly suggests a near Hatteras landfall or whether we are dealing with the main jet in which case there's still every chance we get a sharp turn (Irene being a case in point even if did eventually make a proper landfall).

Fantastic structure this morning. This is how Joaquin looked, how Matthew looked as it approached Haiti and how Earl looked in the hours before it's Belize landfall last year (another 24 hours and they'd have seen a major). It's the classic rugby ball with an eye kind of like that signals an absolute monster coming. 

 

Thinking out loud it may be that the drier surrounding environment it is in combined with low shear and a developed system has aloud Irma to compact itself a bit. 

[Ross Andrew Hemphill]

Quite concerned for my relatives that live in New Jersey. Some of them lost everything from Sandy a few years back and I couldn't imagine how it would feel losing everything once again... 

[summer blizzard]

When one accounts for a slower and more negatively tilted trough (movement more likely between NW/N than NE) it's easy to see that a hit on that south east coast is heavily favoured unless we develop a shortwave. 

[Iceberg]

Raw t numbers are soaring, up to 5.8 given that a 6.0 is a cat 4. 

I certainly agree that anybody in the lighter green zone needs to start thinking about actions they will take. 

[summer blizzard]

Glorious..

First recon in at 7pm tomorrow evening. 

Six hourly missions starting Monday 6pm.

[Iceberg]

Irma is struggling for moisture still. Dry air is wrapping around the hurricane and more so on the southern side. This all had the effect of reducing inflow and starving the hurricane. 

Ita difficult to see it gaining much more until the dry air lifts out in front of it. 

This is all in line with the global s which were resistant to much strengthening at this point. 

[Gray-Wolf]

Irma going through another EWRC and some commentators are now seeing more 'annular' structures meaning Irma may well be more resilient to dry air/ low sst's having better 'staying power' in a way?

A long way to go until we can be sure where She's bound and what strength/size She has attained by then.

I know we have been through a quiet spell in the Atlantic Basin recently but the Pacific side has been seeing huge typhhons and really astonishingly rapid development. Now conditions aloft appear more favourable for development in our basin should we expect to be seeing faster forming, bigger Storms?

[Iceberg]

Gfs 12z very similar to the last few runs. Still saying sub 900mb

[The PIT]

Latest Bulletin here http://www.nhc.noaa.gov/text/refresh/MIATCDAT1+shtml/020850.shtml?

SST's are described as luke warm and with the dry air around it's going to have to wait until it gets into warmer waters but then shear goes up.

[Iceberg]

Gfs ends with a carbon copy. Delaware new jerseyish hit as a cat 5 possibly high end 4

[AderynCoch]

The GFS is bonkers. 897mb over the Gulf Stream east of Florida before clipping the Outer Banks at 917mb. That would surely be a record for so far north.

[alexisj9]

7 minutes ago, AderynCoch said:

The GFS is bonkers. 897mb over the Gulf Stream east of Florida before clipping the Outer Banks at 917mb. That would surely be a record for so far north.

Lets just hope the gfs is doing its normal over the top stuff with this.

[Iceberg]

The dry air is lifting at the moment and Irma is growing again. Looking better and t numbers responding. And so the cycle continues. 

[summer blizzard]

Still Euro vs the rest in the short term. Euro has Irma further south than most, taking it through the islands.

[knocker]

[Iceberg]

Euro is a pain for the islands. Including San Juan 

very similar to the last run a touch further south 

Edited September 2, 2017 by Iceberg

[summer blizzard]

Euro is fish food. 

[Iceberg]

Yes a remnant of trough times it perfectly. Picks the speed up prior Bahamas and then drags it north. 

A think the timing has little support tbh. It interesting run. 

[knocker]

Yes it has the trough down eastern North America  splitting at T144 which creates a cut off upper low in the north east which displaces the the blocking ridge.to the north. At the same time it phases with Irma creating a channel for the latter to curve north particularly as the ridge to the west amplifies to some extent. This is still a long way from a done deal.

Edited September 2, 2017 by knocker