Hurricane season 2017

[Paddy]

Is this going to be as bad as the forecasts?
Should Floridians flee?


Terry

The forecasts cover a range of possible outcomes, and the  hurricane plus associated storm surge aren't due for a while yet. But yes, the safest course would be to flee, and the bare minimum would be to be ready to flee as soon as the evac order is given.

[GeoffBeacon]

Climate Change 2007: Working Group I: The Physical Science Basis said

Tropical Cyclones (Hurricanes and Typhoons)

Mid-latitude Storms
Model projections show fewer mid-latitude storms averaged over each hemisphere, associated with the poleward shift of the storm tracks that is particularly notable in the Southern Hemisphere, with lower central pressures for these poleward-shifted storms.

Is the prediction, "fewer mid-latitude storms", from 2007 still valid or have the changes in the jet stream due to Arctic warming changed the story?

[crandles]

http://www.nhc.noaa.gov/text/refresh/MIATCPAT1+shtml/052342.shtml

Pressure down to 916...which should correspond to sustained winds at around 225 mph! But official wind speed is still 185. Thoughts?

Highest sustained windspeed measured in Atlantic is 190mph with pressure of 899. There have been 5 with pressure below 900. Irma is equal second strongest for sustained windspeed but nowhere near top 11 for pressure/intensity. That rule of thumb seems wrong for intense hurricanes.

The question is how the windspeed was so high for the pressure not why the windspeed isn't higher.

[Sigmetnow]

NHC Atlantic Ops:
5 AM AST forecast and key messages for Hurricane #Irma.    Go to hurricanes.gov  for the latest forecast.
https://twitter.com/nhc_atlantic/status/905358608447221761

[Sigmetnow]

#IRMA made landfall on #Barbuda w/ winds of 160 knots. This ties IRMA with 1935 Labor Day #Hurricane in FL for strongest Atlantic landfall.
https://twitter.com/icyclone/status/905333341427187713

Brief video: Saint Martin in the eye just before 7a EDT  #HurricaneIrma #Irma
[IRMA] Saint Martin dans le mur de l'oeil subit les effets de l'ouragan IRMA #iram #ouragan #SaintMartin (Source : Rinsy Xieng)
https://twitter.com/RCI_GP/status/905381154970329088

[Sigmetnow]

Tweeted an hour ago:
#Irma now has the lowest pressure (914 mb) on record outside of the Gulf of Mexico or western Caribbean in the satellite era (since 1966) 😳
https://twitter.com/EricBlake12/status/905374525331841024

515AM Sunrise over cat 5 #Irma (185mph, 914mb) on IR and VIS bands from GOES-16
https://twitter.com/icyclone/status/905333341427187713
Satellite GIF at the link.

[Sigmetnow]

Seeing some serious consensus in overnight in an east FL, Carolina impact. Have not seen this consensus yet with #Irma. Have a plan.
https://twitter.com/EdValleeWx/status/905381941398171648

Some discussion last evening about how 18Z GFS was well east of ensemble track. No longer the case on 00Z run. Clear shift eastward.
https://twitter.com/GarySzatkowski/status/905392084861014016

[Sigmetnow]

Space Weather!

Major X9.3 solar flare! Any coronal mass ejection from this event may cause additional intense geomagnetic storming in the next 48 hrs!
https://twitter.com/severeweatherEU/status/905429600741847040

[Coronal Mass Ejection] produced by M5.5 solar flare on September 4, 2017 is heading toward Earth and is expected to arrive later today (September 6). A G3 - Strong geomagnetic storm watch is in effect for September 6 and 7

https://watchers.news/2017/09/06/x-class-solar-flare-september-6-2017-cme-produced-strongest-flare-of-solar-cycle-24/


I'm having trouble getting to the NWS Space Weather warnings -- the site may be overwhelmed.

If a CME arrives at Earth, it can produce a geomagnetic storm, which, in turn, can cause anomalies and disruptions to the modern conveniences we have come to rely on. For example, fluctuating magnetic fields associated with these storms induce currents in long wires like power lines, potentially leading to wide-spread blackouts in extreme cases. On March 13, 1989, a powerful geomagnetic storm triggered a major power blackout in Canada that left 6 million people without electricity for 9 hours. According to the North American Electric Reliability Corporation (NERC), the flare disrupted electric power transmission from the Hydro Quebec generating station and even damaged some power transformers in New Jersey. Power outages due to space weather are rare events, but evidence suggests that significant effects could occur. Significant power outages may have cascading effects, causing loss of:

Water and wastewater distribution systems
Perishable foods and medications
Heating/air conditioning and electrical lighting systems
Computer systems, telephone systems, and communications systems (including disruptions in airline flights, satellite networks and GPS services)
Public transportation systems
Fuel distribution systems and fuel pipelines
All electrical systems that do not have back-up power

[Sigmetnow]

We are in an X9.3-flare folks! Largest of this #solar cycle! Massive #hamradio blackout. #GPS issues too on dayside of Earth (colors in map)
https://twitter.com/tamithaskov/status/905439724021485568

Images 2 and 3 are from the SPACE WEATHER PREDICTION CENTER page.
http://www.swpc.noaa.gov

[Sigmetnow]

NHC Update, 11am:
Irma now approaching Virgin Islands and Puerto Rico as a potentially catastrophic Category 5.
Florida track shifted east.
https://twitter.com/ericholthaus/status/905445387196129281

[Sigmetnow]

Many tiny islands have taken a direct hit from #Irma. Put together a map of the region with the storm's path highlighting nearby islands.
https://twitter.com/cyclonebiskit/status/905456139793567744

[Sigmetnow]

"limit" on intensity of hurricane windspeeds increases about 18 mph per degree C of SST warming

The limiting intensity of North Atlantic hurricanes scales at about 8 m/s per degree (C) of warming. http://myweb.fsu.edu/jelsner/PDF/Research/ElsnerStrazzoJaggerLaRowZhao2013.pdf

https://twitter.com/jbelsner/status/905405940631052289

[Sigmetnow]

Jaw-dropping GIF at the link.

Another day, another amazing/scary/beautiful #GOES16 VIS loop of #HurricaneIrma
https://twitter.com/danlindsey77/status/905444524142579712

[Sigmetnow]

Latest (12Z) GFS has shifted back west, toward Florida.
Expect further small fluctuations in Irma's forecast track. Meteorology is hard.
https://twitter.com/ericholthaus/status/905460894288764928

[Sigmetnow]

As #IrmaHurricane steadily moves WNW, storm will encounter some of warmest ocean water in tropics on Earth especially around S. Florida
https://twitter.com/ryanmaue/status/905459393852043264

[Archimid]

Well, I did all I could have done to prepare, except for trimming my front yard trees. Now is time to lock down the hatches and ride the storm. I expect wind of up to 85 MPH in my location. I think I'll be ok. I took some before pictures of areas I think vulnerable. Hopefully, I can get you some after pics.

[Sigmetnow]

Well, I did all I could have done to prepare, except for trimming my front yard trees. Now is time to lock down the hatches and ride the storm. I expect wind of up to 85 MPH in my location. I think I'll be ok. I took some before pictures of areas I think vulnerable. Hopefully, I can get you some after pics.

Sorry, Archimid.  Such bad post timing!

[Sigmetnow]

Even with track shifting east a bit we need to talk heavy rain among other impacts with #Irma - all the way into western North Carolina!
https://mobile.twitter.com/Ginger_Zee/status/905457002398273537


This is the long line for sandbags on Miami Beach. Stretches blocks and blocks. #HurricaneIrma @wsvn
https://twitter.com/brianentin/status/905439409952182273
Video at the link.

[Sigmetnow]

Astonishing video starting to come in of cat 5 Irma winds in Barbados
https://twitter.com/Read4Ks/status/905257372066750466

Happens to be from a tornado last year... ignore.

That makes a lot of sense.  Will delete!!!

But still: sorry, Archimid....

[Archimid]

Oh no, Sigmetnow. I thank you with all my heart for the job you have done on this thread. This has been my go to place for reliable info. Thanks to it, I started scheduled last minute preparations early and had plenty of time to tighten up the place.

I admit, it is scary. I'm not sure what to expect, the eye will pass 60 miles to my North over the next 24 hours. My biggest vulnerability is created by my own trees. They held up during hurricanes Hugo and George, so I'm hoping they hold again.  My other worry are my windows. My house is made out of concrete but the windows are a weak point. The next 24 hours might be very long.

The next few weeks and months will probably suck. No power, no water and probably significant cleanup and rebuilding. But whatever. I'm ready. 

[Sigmetnow]

What Miami, Florida TV is showing:

Here is the latest forecast track on #Irma
https://mobile.twitter.com/PhilFerro7/status/905460865998213122

[Sigmetnow]

Oh no, Sigmetnow. I thank you with all my heart for the job you have done on this thread. This has been my go to place for reliable info. Thanks to it, I started scheduled last minute preparations early and had plenty of time to tighten up the place.

I admit, it is scary. I'm not sure what to expect, the eye will pass 60 miles to my North over the next 24 hours. My biggest vulnerability is created by my own trees. They held up during hurricanes Hugo and George, so I'm hoping they hold again.  My other worry are my windows. My house is made out of concrete but the windows are a weak point. The next 24 hours might be very long.

The next few weeks and months will probably suck. No power, no water and probably significant cleanup and rebuilding. But whatever. I'm ready. 

 I will be thinking of you!

I limit what I post elsewhere for people who have friends and relatives in Florida, to give them just the essentials -- what they or their friends need to know... without, I hope, scaring them too much. 

[oren]

Oh no, Sigmetnow. I thank you with all my heart for the job you have done on this thread. This has been my go to place for reliable info. Thanks to it, I started scheduled last minute preparations early and had plenty of time to tighten up the place.

I admit, it is scary. I'm not sure what to expect, the eye will pass 60 miles to my North over the next 24 hours. My biggest vulnerability is created by my own trees. They held up during hurricanes Hugo and George, so I'm hoping they hold again.  My other worry are my windows. My house is made out of concrete but the windows are a weak point. The next 24 hours might be very long.

The next few weeks and months will probably suck. No power, no water and probably significant cleanup and rebuilding. But whatever. I'm ready. 

Good luck Archimid! A concrete house is great. It will keep you safe, the rest are details.

[Archimid]

Don't hold back for me! That's why hang around here.    Nothing scarier than watching the Arctic disappear right in front my eyes, so post away. I really can't overstate the wonderful job you are doing.

[Sigmetnow]

Shocking: Power utility company in Puerto Rico estimates Island will be without electricity for "4 to 6 months."
http://www.miamiherald.com/news/weather/hurricane/article171465667.html

Here's hoping companies like Tesla can help out with solar + batteries, the faster the better!

[Neven]

I wish you and everybody on your island the best of luck, Archimid. And I hope your mango tree gets through okay as well!

Please, let us know how you are as soon as you can.

[Archimid]

Thanks for the good thoughts. The mango tree looks strong and healthy. He is young and flexible and with few leaves. Because I planted it during a drought I'm hoping he has deep roots. I think he'll be ok.

My first hope is that Irma takes a turn for the north and leave us be, but if it doesn't, I'm hoping to get some good pictures, maybe even video to share with you. My area is expecting winds of about 80 mph. Those are the fastest wind speeds I have ever experienced so I'm not sure what to expect.

[jai mitchell]

CNN reports that 6 hours after a direct hit to the tiny island of Barbuda no one has yet heard from them. . .

https://twitter.com/CNN/status/905478738820964352

[Pmt111500]

Stay safe, Archimid. 80Mph is about the strongest gust I've experienced, this made me lose footing and drop to all fours. That is no weather for any business outside, but we had to as it was military. The things army makes you do. Guessing your gusts will be around 100mph so people outside might fly off the streets if they're fool enough to try to walk outside. Our barracks windows held together ok but never I've heard such noise from windows before or after.

[wili]

Jai, that's strange, 'cause I swear I saw a report form NYT that said that the roof had come off of the police station at Berbuda, forcing the officers to take shelter in the fire station. There were other reports of damage, but not of massive deaths or anything.

But now I can't find reference to that at the NYT site. Hard to tell what's fake news anymore.


ETA:
Yeah, there have been reports from the island...just look at comments to the post you linked to, which includes a link to this statement from the local official:

https://www.abconsulate.nyc/single-post/2017/09/06/Official-Statement-by-the-Hon-Gaston-Browne-Prime-Minister-of-Antigua-and-Barbuda-after-hurricane-Irma

With regard to Barbuda, preliminary reports indicate damage to rooves and to some buildings, but I have had no report of any fatalities. Barbuda too benefited from a high level of readiness, responsive to the urgings of the government and from the preparations that were made in advance, including the shelter constructed for that purpose.

New update from the scribbler:
https://robertscribbler.com/2017/09/06/models-show-irma-tracking-toward-88-degree-f-waters-before-setting-sights-on-florida-georgia-and-south-carolina/

And from cat6: https://www.wunderground.com/cat6/category-5-irma-hits-leeward-islands-peak-strength

[IMeretricious]

I hate to be such a cynic in a time like this, but that statement doesn't mention anywhere that contact has been reestablished with Barbuda since Irma passed over.

On twitter, people with family on the island are still searching for any word from Barbuda as of a few minutes ago.

[jai mitchell]

article published 30 minutes ago.

http://www.express.co.uk/news/weather/850811/Hurricane-Irma-path-track-models-update-Barbuda-contact-lost-damage-video

Hurricane Irma UPDATE: Barbuda diplomat says ALL CONTACT has been lost with island

HURRICANE IRMA has interrupted all communications between the Caribbean island of Barbuda with nearby islands after concerning reports recorded devastating consequences on local buildings.

Karen-Mae Hill, Antigua and Barbuda's High Commissioner,  told Sky News all contact with the island was lost shortly after midnight.

She said: "We have not been able to make any contact with Barbuda since about midnight UK time.

"The last report we had from our sister island was the police station was destroyed, the roof came off completely. Houses all around Codrington, the main settlement on Barbuda, have lost their roofs.

[morganism]

Does the churn from Irma cool or warm the ocean behind it? Am looking at Jose, and wondering if Irma is steering air and creating a backwash, to push Jose further west, rather than the modeled northerly track.

[jai mitchell]

modeled track for Katia is South and East

[oren]

Does the churn from Irma cool or warm the ocean behind it? Am looking at Jose, and wondering if Irma is steering air and creating a backwash, to push Jose further west, rather than the modeled northerly track.

Cyclones definitely cool the ocean as they traverse it, mostly from wind-driven evaporation and upwelling, but also from shading the ocean, and raining on the ocean surface. This makes it harder for other cyclones on the same path to achieve the same strength. Not sure how Irma is affecting the air currents and steering though.

[wili]

Thanks for that clarification, jai. I shudder to think...

oren, the problem these days is that gw has heated the water more deeply than before, so even as evaporation cools the surface, what upwells to take its place is often just about as hot.

[jai mitchell]

St. Martin video of storm from remotely operated camera. . .what planet is this???

https://twitter.com/MeteoExpress/status/905402131481493504

[logicmanPatrick]

I just popped in to say to Archimid : "My very best hopes, thoughts and wishes for your safety."

And to Sigmetnow - a name most apt at this time: "I join with others to express my gratitude for your efforts on the ASIF and particularly in this thread."

And thank you all.  The ASIF should be the first port of call for any self-respecting reporter who wants the pukka gen on climate, just as is PPruNe for aviation matters.

Edit - from PPruNe - Hurricane? THIS is a hurricane.

Here is a later TAF. No METAR since 0800 this morning. I have never seen winds like this in a weather message:

TNCM 061121Z 0612/0712 300120G140KT 1SM +RA BKN015 OVC030
FM061500 250/60G80KT 5SM -SHRA BKN025 BKN050
FM061900 18035G50 P6SM -SHRA SCT025 BKN060
FM070000 15020G30 P6SM FEW025 SCT060

From wikipedia: Terminal aerodrome forecast
Each line beginning with FM indicates a rapid change in the weather over a period of less than an hour.

[Sigmetnow]

#Irma has now maintained 185 mph winds for 24 hours - no Atlantic or eastern Pacific #hurricane has ever stayed this strong for so long.
https://twitter.com/ericblake12/status/905503972382912512


Really good news: The eye of Irma is already moving north of Puerto Rico -- meaning the worst of the winds should remain safely offshore.
https://twitter.com/ericholthaus/status/905516608604565504

The #radar this afternoon of #Irma is absolutely textbook as it moves poleward of #PuertoRico's latitude. Eyewall should miss island.
https://twitter.com/pppapin/status/905515465988071426
Radar GIF at the link.

[Archimid]

Those are great news indeed. I'm already without power, but to be honest it lasted more than I thought it would. There are already 30-40 mph outside. Mango tree looking good.

[Sigmetnow]

.@Space_Station cameras captured another dramatic view of #HurricaneIrma as it made landfall in the Caribbean today:

https://twitter.com/nasa/status/905513994341015553
Video at the link.

[morganism]

As of 4PM, Jose and Katia have strengthened into Hurricanes. @NHC_Atlantic's next advisories will be issued at 5PM

edit:

http://www.nhc.noaa.gov/cyclones/

 @philklotzbach

The Atlantic now has 3 hurricanes active at the same time: #Irma, #Jose and #Katia. The last time this occurred was September 16-17, 2010.

[Sigmetnow]

First contact has been made on the tiny Island of #Barbuda
https://twitter.com/eustormmap/status/905532695991681024

[AbruptSLR]

Scribbler adds color commentary to many of the issues already addressed in this thread:

Title: "Models Show Irma Tracking Toward 88 Degree (F) Waters Before Setting Sights on Florida, Georgia and South Carolina"

https://robertscribbler.com/2017/09/06/models-show-irma-tracking-toward-88-degree-f-waters-before-setting-sights-on-florida-georgia-and-south-carolina/

Extract: "As of yesterday and today, Irma was the strongest storm ever to form in the Central Atlantic. Fueled by record atmospheric and ocean heat and related high atmospheric moisture content, the storm plowed into the Leeward Islands of Barbuda, St. Martin and Anguilla as a top-strength Category 5 monster hurricane."

[Sigmetnow]

Hard to believe we've been able to generate loops like this 3 days in a row. Center of powerful #Irma just north of Puerto Rico. #GOES16
https://twitter.com/nasa_sport/status/905539907938082816
GIF at the link.

[Sigmetnow]

Houston:

LISTEN: Updates on Addicks & Barker Reservoirs from @JeffLindner1 and @hcfcd
https://t.co/fW0O9GEbPR?amp=1

https://twitter.com/DisasterPIO/status/905453122700619778

[Sigmetnow]

Image:  5 pm update from the NHC.

Irma tightens aim on South Florida east coast
http://amp.miamiherald.com/news/weather/hurricane/article171611132.html

IRMA is currently 500 miles wide.
Florida is 100 miles wide.

[Sigmetnow]

The good news: the models have come into agreement. The bad news: the models have come into agreement. 
NHC forecasts a Category 4 landfall near Miami.

Eric Holthaus:
Agreement like this boosts forecaster confidence. What's more, every single sub-model of GFS (21) & ECMWF (51) show a US mainland landfall.

What's not guaranteed at this stage is the specifics of the U.S. mainland landfall. Could be South Florida, could be Carolinas. Cat 2-5 psbl

In the worst-case scenario, Irma would hit the Miami area as a Cat 5, then ride up the east coast of Florida into the Carolinas as a Cat 3+

That's nearly what the official NHC forecast calls for right now. (Though with Miami-area landfall at Cat 4.)

The worst-case Irma scenario would be a nearly unimaginable catastrophe -- the worst natural disaster in U.S. history, and could cost $300B+

https://twitter.com/ericholthaus/status/905552049223368704

[Archimid]

The local media reports that 42% of the island is without power. Some branches are already falling from my trees.

[Sigmetnow]

Sept 6th PM Barbuda Ham Radio Out, Satellite Phone Service Destroyed per PM
Facebook live video:  https://t.co/ObF4ZdF30G  They are letting people speak to the camera.

https://mobile.twitter.com/northlandfox/status/905552986021261312
Photos at the link.