atlantic Major Hurricane Joaquin

[lorenzo]

Great Tweet from Dr. Maue showing the various EPS members in GIF format from tonights 12z.

 

https://twitter.com/RyanMaue/status/649319199702167553

 

Decent write up here https://www.washingtonpost.com/blogs/capital-weather-gang/wp/2015/09/30/current-weather-pattern-is-notorious-for-mid-atlantic-hurricane-landfalls/

 

Also, this paper published after Sandy discussing the impact of the Greenland Block on steering is relevant.

 

http://onlinelibrary.wiley.com/doi/10.1002/joc.4018/abstract

 

ECM plus control and decent chunk of ENS catapult Joaquin out East.

 

But, when have we known the ECM and it's entire gang of ENS members to be wrong.

 

A decent model battle here..

 

 

[Sainsbo]

Big westward shift in the NHC advisory, now expecting a category 2 landfall over Chesapeake

[lorenzo]

http://www.nhc.noaa.gov/#JOAQUIN

 

Interesting discussion citing the standalone ECM, also the loading of extra recon for the 00z.

 

Liked the IR here also http://www.aviationweather.gov/satellite/plot?region=carib&type=ir

 

000

WTNT41 KNHC 302055

TCDAT1

 

HURRICANE JOAQUIN DISCUSSION NUMBER  12

NWS NATIONAL HURRICANE CENTER MIAMI FL       AL112015

500 PM EDT WED SEP 30 2015

 

There has been little change in the organization of Joaquin during

the past several hours.  While the hurricane continues to produce

cloud tops colder than -80C in the eyewall, the eye has not become

better defined since the last advisory.  Satellite intensity

estimates are 77 kt from both TAFB and SAB, so the advisory

intensity is now 75 kt.

 

The initial motion is 225/7.  The shortwave ridge causing this

motion is expected to weaken during the next 24-48 hours as a strong

deep-layer trough develops over the southeastern United States.

Thus, a generally southwestward motion is expected for the next 36

hours or so, followed by a turn toward the north as the trough

becomes the dominant steering mechanism.  There is an increased

disagreement between the GFS, UKMET, Canadian, and NAVGEM models

versus the ECMWF since the last advisory.  The ECMWF has continued

its forecast of showing a northeastward motion after 72 hours,

taking Joaquin just west of Bermuda and out to sea.  The other

models have all shifted their forecasts to the left and now

call for landfall in the Carolinas and the mid-Atlantic states,

followed by merger with the baroclinic trough.  Given the shift in

the non-ECMWF models, a major westward adjustment has been made to

the forecast track at 96 and 120 hours, bringing the center of

Joaquin near or over portions of the mid-Atlantic states.  Due to

the use of the ECMWF in the consensus models, the new track lies

near the various consensus models.  However, it lies well to the

east of the GFS and the other similar models.  The NOAA G-IV jet is

currently flying a synoptic surveillance mission, which, along with

special rawinsonde launches, hopefully will reduce the spread of the

guidance.

 

There is little change to the intensity forecast philosophy since

the last advisory.  Joaquin is expected to remain in an environment

of moderate northeasterly vertical shear for the next 24-36 hours,

possibly including strong winds seen at 400 mb in recent dropsondes

from the G-IV aircraft.  However, since it has been steadily

strengthening in such an environment, there is no obvious reason to

think it will stop doing so.  After 36 hours, the hurricane is

likely to move into an area of divergent southerly upper-level winds

associated with the eastern U. S. trough.  While there is

uncertainty as to how much shear should occur, it is expected that

additional intensification could occur through at least 48 hours.

Based on this, the intensity forecast calls for Joaquin to peak as a

major hurricane in 48-72 hours, and it is possible it could be

stronger than currently forecast.  After 72 hours, increasing shear,

cold air intrusion, and land interaction should cause weakening and

the start of extratropical transition.

 

 

KEY MESSAGES:

 

1.  Preparations to protect life and property within the warning

areas in the Bahamas should be rushed to completion.

 

2.  A significant adjustment to the forecast has been made this

afternoon, and this shows an increased threat to the mid-Atlantic

states and the Carolinas.  However, confidence in the details of the

forecast after 72 hours remains low, since we have one normally

excellent model that keeps Joaquin far away from the United States

east coast.   The range of possible outcomes is still large, and

includes the possibility of a major hurricane landfall in the

Carolinas.

 

3.  Every effort is being made to provide the forecast models with

as much data as possible.  The NOAA G-IV jet has begun a series of

missions in the storm environment, and the National Weather Service

is launching extra balloon soundings.

 

4.  Because landfall, if it occurs, is still more than three days

away, it is too early to talk about specific wind, rain, or surge

impacts from Joaquin in the United States.   Even if Joaquin stays

well out to sea, strong onshore winds will create minor to moderate

coastal flooding along the coasts of the mid-Atlantic and

northeastern states through the weekend.

 

5.  A hurricane watch for a portion of the U.S. coast could be

required as early as Thursday evening.

 

6.  Many areas of the eastern U.S. are currently experiencing heavy

rains and gusty winds associated with a frontal system.  This

inclement weather is expected to continue over the next few days,

which could complicate preparations for Joaquin should it head

toward the coast, and greatly exacerbate the impacts from the

hurricane.  Heavy rains are likely to continue over these areas

even if the center of Joaquin stays out to sea.

[summer blizzard]

Loving those key points. A red meat cane potentially hitting land.

[mountain shadow]

Incredible that the ECM is so different to the others.

Tomorrow mornings runs will be very interesting.

I'm siding with the ECM. It's to good to be that wrong.

[summer blizzard]

It looks like we are now a main sub-forum rather than hid so hopefully more thread activity.

Recon are en route.

I suspect they'll find pressure around 960mb.

[Singularity]

Vast improvement to the eye wall structure over the past few hours, but the eye itself remains largely obscured as hot towers keep on firing all around - a sign of a storm gaining intensity at a steady clip. Link to the microwave image sequence:

 

http://tropic.ssec.wisc.edu/real-time/mimic-tc/2015_11L/webManager/gifsBy12hr_05.gif

 

The storm does look to still be having to deal with some wind shear and dry air issues on the northwestern side, but that situation is slowly improving with time. It's a long old night coming for many parts of the Bahamas it has to be said.

 

 

This image just caught my eye - you can see all the hot towers overshooting the boundary layer, they look like pimples:

 

 

 

 

. . .

 

Meanwhile, it appears a tropical storm (or something very close to that) has formed just east of Minorca in the Mediterranean. I had long wondered how long it would be before I found myself writing such a thing! 

I just read this on wunderground in blog comments:

 

"Yes, there is a very rapid development typical of these systems, according to local WRF models it's likely to make landfall in Sardinia or Corsica tomorrow evening/night with winds around 100/120 km/h but the uncertainty is very high. Recent surface observations in Menorca reported sustained winds of 60/70 km/h and gusts above 100 km/h, the movement should be toward the east in the next hours."

 

If it really kicks off, it may merit its own thread? Sorry to keep tagging this on to the Joaquin discussion 

[summer blizzard]

Pinhole eye now visible.

Nhc have gone with 954mb, 105mph. Category 2.

Recon just found 949mb, 102kt (117mph).

Can't rule out a category 4 peak.

[Sainsbo]

Recon has just found FL winds of 130kts, looks like it might already be a catgory three.. Not good news.

 

 

 

Some ADT values here, though they aren't of much use in the Atlantic when we have regular recons

 

http://www.ssd.noaa.gov/PS/TROP/DATA/2015/adt/text/11L-list.txt

[Somerset Squall]

Well this is a surprise given the early forecasts had this system peaking at a mere 35kts! Winds are at 100kts currently (cat 3 major, second of the season,the first being Danny) and expected to peak at 120kts (cat 4). Certainly a bumpy ride for the Bahamas, and later on the Carolinas on the east coast. Model guidance is constantly shifting west as Joaquin continues moving towards the southwest moreso than expected, meaning the northward turn is probably going to happen too late to spare the east coast of the USA.

[Gray-Wolf]

I'm not ready to call a 'max' cat. on Joaquin quite yet!

 

I've been reading that the waters she's over are the warmest they have ever recorded at and that this is true down to 50m??

 

As she wibbles about in that area , before she moves off north, I reckon she will have enough time to become real strong ( cat 5?)?

[radiohead]

Well this is a surprise given the early forecasts had this system peaking at a mere 35kts! Winds are at 100kts currently (cat 3 major, second of the season,the first being Danny) and expected to peak at 120kts (cat 4). Certainly a bumpy ride for the Bahamas, and later on the Carolinas on the east coast. Model guidance is constantly shifting west as Joaquin continues moving towards the southwest moreso than expected, meaning the northward turn is probably going to happen too late to spare the east coast of the USA.

 

I would say that there has been an eastward shift in the model guidance from the GFS and UKMO. 0Z GEFS has suddenly shifted towards the ECM's solution too. It's too early to say but I think now the ECM will probably be right with it's track, out to sea, maybe clipping the Canadian coast when extratropical.

Edited October 1, 2015 by radiohead

[Yarmy]

Penn State WRF is closer to the Euro outcome:

 

http://hfip.psu.edu/realtime/AL2015/forecast_track.html

 

 

 

Going to be egg on the face of some major models at the end of this. 

[mountain shadow]

It's the current meandering of the system causing the headaches with nothing currently really steering it.

Fascinating inter model differences.

[Lauren]

Making landall in Virginia where they have a lot of low lying land would cause some awful flooding.

[radiohead]

Latest forecast track has shifted eastward.

 

[Singularity]

The average intensity of the convection and spatial extent combined is about as impressive as I can recall seeing in the Atlantic basin, yet the storm is far from photogenic and how often do you get a major hurricane that lacks a clear eye feature?

 

Looking like some kind of super-vigorous central dense overcast, it bears more resemblance to spinning top than a cyclone. It has the impressive pressure drop associated with an eye though, down 37 mb in the space of 18 hours which is something you'd be hard pressed to find with a non-tropical cyclone!

 

So clearly an eye exists, it's just that it's not, ahem, clear   

 

Without recon, the satellites can only see an 80 knot storm with a 977 mb central pressure... do'h!

 

 

The number of named storms this season has now reached 10, which is as high as most forecasts went this year, and the number of majors is now 2, as opposed to just the 1 that most organisations expected.

 

With wind shear falling away further today and into tomorrow, perhaps even becoming light, and such high SSTs coupled with an environment that can sustain powerful outflow channels to ventilate the storm, this storm does seem to have the best shot at becoming a category 5 that we've seen in many, many years. If it happened it would be the first in the Atlantic basin or Caribbean since 2007   

[summer blizzard]

Eyewall is open at the moment.

120mph, 948mb. Forecast to peak at cat 4.

UKMO capitulated to the Euro so hopes still rest with the GFS and GEM.

[Yarmy]

GFS 06z heading out to sea:

 

[Yarmy]

Huge eastward shift from the GFS. Barring any backtracks...

 

[Summer Sun]

The beebs pic tweeted at 11:34 has it heading towards NYC

 

[Singularity]

Now we just need to watch out to see if the storm tracks further south/southwest than what even ECM has been showing. That would start up a whole new ball game... still the outside chance I suspect but it will be crazy if the trough doesn't perform the task that the models are expecting it to.

 

Right now, the Bahamas are getting pummeled, especially for a hundred or so miles east of Long Island.

[mountain shadow]

Huge eastward shift from the GFS. Barring any backtracks...

 

This is why ECM is king.

[radiohead]

Deepened to 942mb now. It may be a little deeper. 06Z GFS had it around 955mb at this time.

[summer blizzard]

Recon has found 939mb, 134mph.

Probably category 4 and looking exceptional.