Major Hurricane Irma

[yoda]

Hurricane Irma Discussion Number  30
NWS National Hurricane Center Miami FL       AL112017
1100 AM AST Wed Sep 06 2017

The eye of Irma passed over Barbuda, St. Barthelemy, and St. Martin
this morning, and will be moving over portions of the British and
U.S. Virgin Islands shortly.  A NOAA National Ocean Service
observing site on Barbuda measured sustained winds of 103 kt with a
gust to 135 kt earlier this morning before the anemometer failed.
The station also reported a minimum pressure of 916.1 mb.  A minimum
pressure of 915.9 mb was reported on St. Barthelemy.  An Air Force
reconnaissance aircraft that performed a single pass through the eye
this morning reported SFMR winds of 152 kt in the northwestern
eyewall around 12Z.  Assuming there are stronger winds in the
northeastern eyewall, the initial intensity remains 160 kt for this
advisory.  Another Air Force aircraft is currently entering the
storm.

Irma is moving west-northwestward or 285/14 kt.  A strong high
pressure ridge extending from the central Atlantic westward is
expected to keep Irma moving west-northwestward during the next 2
to 3 days.  The track guidance is in good agreement during this
period and the NHC track is along the southern edge of the guidance
envelope in best agreement with the ECMWF and HFIP corrected
consensus model.  After that time, a shortwave trough moving
southward over the east-central United States is expected to erode
the western portion of the ridge.  As a result, Irma is forecast to
turn northwestward and northward, but there is still a fair amount
of uncertainty regarding the exact timing and location of
recurvature.  The NHC forecast has been shifted eastward to be in
better agreement with the latest model guidance, however it should
be noted that there are numerous GEFS and ECMWF ensemble members
that take Irma over and/or west of Florida.  The updated NHC track
is in best agreement with the latest ECMWF ensemble mean.  Users are
reminded that the average NHC track errors at days 4 and 5 are
about 175 and 225 statue miles, respectively.

Irma is forecast to remain within favorable atmospheric conditions
and over warm waters during the next 3 to 4 days.  Therefore, Irma
is likely to remain a very powerful hurricane during this time, and
the NHC intensity forecast is unchanged from the previous advisory
through day 4.  Since the 120-h forecast point is now offshore, the
intensity forecast at that time has been adjusted accordingly.

Now that Irma's eye is clearly visible in radar imagery from San
Juan, Tropical Cyclone Updates with hourly position estimates
will be issued starting at 1200 PM AST (1600 UTC).


KEY MESSAGES:

1. Irma is a potentially catastrophic category 5 hurricane and will
bring life-threatening wind, storm surge, and rainfall hazards to
portions of the northern Leeward Islands, including the Virgin
Islands and Puerto Rico today.

2. A hurricane warning is in effect for the northern coast of the
Dominican Republic, the southeastern Bahamas, the Turks and
Caicos, and portions of Haiti, with a hurricane watch in effect for
the central Bahamas and much of Cuba.  Irma is likely to bring
dangerous wind, storm surge, and rainfall to some of these areas
tonight through Friday.

3. Irma could directly affect the remainder of the Bahamas and Cuba
as an extremely dangerous major hurricane later this week. Residents
in these areas should monitor the progress of Irma and listen to
advice given by officials.

4. Direct impacts from wind, storm surge, and rainfall are possible
in the Florida Keys and portions of the Florida Peninsula beginning
later this week and this weekend.  However, given the forecast
uncertainty at these time ranges, it is too soon to specify the
location and magnitude of these impacts.


FORECAST POSITIONS AND MAX WINDS

INIT  06/1500Z 18.2N  64.0W  160 KT 185 MPH
 12H  07/0000Z 19.0N  66.2W  155 KT 180 MPH
 24H  07/1200Z 20.2N  69.0W  150 KT 175 MPH
 36H  08/0000Z 21.2N  71.7W  145 KT 165 MPH
 48H  08/1200Z 21.9N  74.2W  140 KT 160 MPH
 72H  09/1200Z 22.9N  78.1W  135 KT 155 MPH
 96H  10/1200Z 25.2N  80.0W  125 KT 145 MPH
120H  11/1200Z 29.0N  80.5W  110 KT 125 MPH

$$
Forecaster Brown

[OUGrad05]

7 minutes ago, jojo762 said:

Recon just measured 150kt SFMR in the SW eye wall.

That's pretty impressive

[jojo762]

2 minutes ago, OUGrad05 said:

That's pretty impressive

All four quads have had cat 5 SFMR winds for quite some time now. Pretty rare. 

[bdgwx]

I'm seeing at lot of 150+ kt bins at 15,000 ft. The eye is about 20 nm wide. 

[McQuackleton]

Latest NHC Forecast

[OUGrad05]

1 minute ago, jojo762 said:

All four quads have had cat 5 SFMR winds for quite some time now. Pretty rare. 

Yes very rare.  Windfield continues to slowly expand as well. 

[Hurricane Agnes]

1 minute ago, AcePuppy said:

Latest NHC Forecast

The cone did shift east from the 8 am version.

[RU4Real]

I haven't seen this mentioned yet, but based on recollection the 14 kt motion seems unusually fast for a storm of this caliber.

[jojo762]

~165kt FL winds in the northeast eye wall per Recon (190mph).

[jbcmh81]

4 minutes ago, jojo762 said:

~165kt FL winds in the northeast eye wall per Recon (190mph).

No weaker despite a bit poorer satellite appearance this morning.   She's a beast.  If she can avoid much land interaction, it's hard to see the steady weakening the NHC calls for.

[bluewave]

#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://mobile.twitter.com/EricBlake12/status/905374525331841024?p=v

 

#Irma has now had max winds of 180+ mph for past 24 hrs - an Atlantic hurricane record. Old record was Allen w/ 18 hours of 180+ mph winds

https://mobile.twitter.com/philklotzbach/status/905445230005989377?p=v

[LakeEffectKing]

3 minutes ago, jojo762 said:

~165kt FL winds in the northeast eye wall per Recon (190mph).

Actually down a bit from yesterday's NE FL winds....(I think some where near 190kts)

[lakeeffectkid383]

It looks to me like the eye is beginning to shrink just a bit and on satellite it looks like the total width of the storm is increasing. 

[pazzo83]

I think we'll see the next period of deepening once she hits the literal bath waters near the Bahamas.  SSTs around 90 f'ing degrees there.

[Blue Ridge]

5 minutes ago, pazzo83 said:

I think we'll see the next period of deepening once she hits the literal bath waters near the Bahamas.  SSTs around 90 f'ing degrees there.

Makes one wonder just how far she can go prior to potential Cuban disruption. Do we see 200 MPH?

[Upper Level LOL]

1 minute ago, pazzo83 said:

I think we'll see the next period of deepening once she hits the literal bath waters near the Bahamas.  SSTs around 90 f'ing degrees there.

Yeah I think this weekend is gonna be one of anxious clenching and satellite watching. Irma's going to explode ~50 miles from the Florida coast as we all watch to see when the turn begins

[NavarreDon]

airplus‏ @airplusnews

 

 

 

 

L'aéroport de Saint Martin dévasté après le passage d'Irma!

6:47 AM - 6 Sep 2017

 

       

 

 

 

 

 

 

 

[EasternLI]

[pazzo83]

jfc is that the inside of the airport in photos 1 & 3?

[NavarreDon]

1 minute ago, pazzo83 said:

jfc is that the inside of the airport in photos 1 & 3?

Best I can tell....yes!

[hooralph]

4 minutes ago, pazzo83 said:

jfc is that the inside of the airport in photos 1 & 3?

Yep. Been through there many times, on the way to Saint Barths.

Recovery for all three of those islands (including Anguilla) will be brutal, but especially SBH. The harbor was inundated and the airport can only take prop planes that come in from SXM or SJU.

[taylorsweather]

Amazing video of the bus rescue.  Shows the greatness in people when lives are at stake.

[bluewave]

 

[jojo762]

NE eye wall is very impressive. Unusually large area area of 130kt+ and 100kt+ winds

[loshjott]

2 minutes ago, Taylorsweather said:

Amazing video of the bus rescue.  Shows the greatness in people when lives are at stake.

Where was that taken?

[nwohweather]

I don't see anyway this thing weakens before FL without a hit on Cuba. That water is like jet fuel to her west with little shear and dry air to speak of.

IMO the NHC has to realize this thing is like Michael Jordan, it's going to do things nothing else has before

[jaxjagman]

4 minutes ago, loshjott said:

Where was that taken?

Apparently is was a hoax and not real,it was taking off

[NJwx85]

Posted this earlier, still looks to be the same. St. Thomas is going to take a direct hit unless a significant Northern shift occurs very soon. According to the radar, an island wide tornado warning has been issued for that island, although I cannot locate the text anywhere.

[gymengineer]

3 minutes ago, NJwx85 said:

Posted this earlier, still looks to be the same. St. Thomas is going to take a direct hit unless a significant Northern shift occurs very soon. According to the radar, an island wide tornado warning has been issued for that island, although I cannot locate the text anywhere.

Extreme Wind Warning
VIC020-030-061715-
/O.NEW.TJSJ.EW.W.0001.170906T1516Z-170906T1715Z/

BULLETIN - EAS ACTIVATION REQUESTED
Extreme Wind Warning
National Weather Service San Juan PR
1116 AM AST WED SEP 6 2017

The National Weather Service in San Juan has issued a

* Extreme Wind Warning for...
  Saint John in Virgin Islands...
  Saint Thomas in Virgin Islands...

* Until 115 PM AST

* At 1114 AM AST, National Weather Service Doppler radar indicated
  extreme winds, associated with the eyewall of Major Hurricane
  Irma, about to move over St John, moving west at 20 mph. This
  extreme winds will affect St John and St Thomas through 100 PM
  AST. This is an extremely dangerous and life-threatening situation!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Treat these imminent extreme winds as if a tornado
was approaching and move immediately to the safe room in your
shelter. Take action now to protect your life!

The safest place to be during a major landfalling hurricane is in a
reinforced interior room away from windows. Get under a table or
other piece of sturdy furniture. Use mattresses, blankets or pillows
to cover your head and body. Remain in place through the passage of
these life-threatening conditions.

[loshjott]

3 minutes ago, NJwx85 said:

Posted this earlier, still looks to be the same. St. Thomas is going to take a direct hit unless a significant Northern shift occurs very soon. According to the radar, an island wide tornado warning has been issued for that island, although I cannot locate the text anywhere.

I don't see that on the local NWS page: http://forecast.weather.gov/MapClick.php?lat=18.349&lon=-64.9304#.WbAVPnZ959M

 

EDIT: or see above for extreme wind warning.