ATL: IRENE - Remnants - Discussion

[Nimbus]

So this is where we are obviously NHC sees a major hurricane headed dangerously close to Florida. "stronger ridge than modeled"


Hurricane Irene Discussion Number 7
Statement as of 5:00 am AST on August 22, 2011
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Irene has become much better organized during the past 6 hours
despite its interaction with the mountainous terrain of Puerto
Rico...and a ragged eye has become apparent in imagery from the FAA
terminal Doppler weather radar. Also...large patches of Doppler
velocity values as high as 75-82 kt at 1000-1500 ft and 85-91 kt
at 2000-3000 ft have been indicated northwest and northeast of the
center over water for the past 2 hours...which equates to at least
65-kt surface winds. Some Doppler velocities as high as 72 kt have
also been detected at 500-600 ft over water. As a result of these
data...Irene has been upgraded to the first hurricane of the 2011
Atlantic hurricane season.

Trending through all of the wobbles in the track over the past 6
hours yields an average motion of about 290/10 kt. Upper-air data
at 00z indicate 500 mb heights have not changed at Bermuda in the
past 24 hours...which suggests that the subtropical ridge to the
north of Irene remains quite strong. The ridge is expected to
change little for the next 48 hours or so...which would act to keep
Irene moving in a general west-northwestward direction off the
north coast of Puerto Rico this morning and just skirting the
northern coast of Hispaniola later today and on Tuesday. After
that...the global models diverge on the specifics of how large a
break or weakness in the subtropical ridge develops over Florida
and the southeastern U.S. At 72 hour and beyond...which will allow
Irene to move northwestward. The ECMWF...NOGAPS...and GFDN models
are the rightmost of the NHC model guidance suite and keep Irene
Well east of Florida...whereas the UKMET and the GFDL models are
the leftmost of the models and take Irene near the West Coast of
Florida. The GFS and the rest of the NHC model guidance is tightly
packed between these two extremes and take Irene through the
Bahamas and just off the Florida East Coast. What is noteworthy is
that all of the global and regional models agree that the outflow
of Irene will converge with westerly to northwesterly upper-level
mid-latitude flow over the mid-Atlantic states by 96 hours and
beyond. This upper-level mass confluence could maintain the mid- to
low-level ridge a little bit stronger and longer than what NOGAPS
and the ECMWF are forecasting...which would in turn keep Irene a
little closer to the Florida East Coast. As a result...the official
forecast track was only shifted slightly to the east of the
previous track and is near the consensus models tvcn and tvca.

It now appears that Irene will not interact with Hispaniola as much
or as long as previously expected. This will also result in more
strengthening than previously expected. Irene is forecast by all of
the models to have a very impressive outflow pattern throughout the
forecast period...including a large upper-level trough/low about
1200 nmi east of the cyclone acting as a mass sink. With Irene also
expected to be over SSTs near 30c after 48 hours...significant
strengthening could occur. However...the official intensity will
remain on the conservative side due to the uncertainty in how much
Irene will interact with the mountainous terrain of Hispaniola for
the next 24-36 hours. The official intensity forecast is a blend of
the SHIPS/lgem models and the HWRF/GFDL models. However...given the
impressive upper-level flow pattern expected across Irene...it
would not surprise ME if this cyclone became a major hurricane at
some time during its lifetime like the GFDL and HWRF models are
forecasting.

It is important not to focus on the exact forecast track...
especially at days 4 to 5...since the most recent 5-year average
errors at those forecast times are 200 and 250 miles...
respectively.

Forecast positions and Max winds


init 22/0900z 18.4n 66.4w 65 kt 75 mph
12h 22/1800z 18.9n 68.2w 70 kt 80 mph
24h 23/0600z 19.7n 70.5w 70 kt 80 mph...inland
36h 23/1800z 20.4n 72.4w 70 kt 80 mph...over water
48h 24/0600z 21.3n 74.1w 75 kt 85 mph
72h 25/0600z 24.0n 77.1w 80 kt 90 mph
96h 26/0600z 27.0n 79.5w 85 kt 100 mph
120h 27/0600z 30.9n 81.5w 95 kt 110 mph


$$

[dexterlabio]

Interesting to note that Irene became a hurricane even as it lingers in the northern part of Puerto Rico. I'm not from the US but I'm hoping that all folks along the SE coast are aware and prepared for this.

[GCANE]

Outflow is ideal, this is something I would typically see with one of the WPAC monsters.

Poleward-outflow-channel is running 60 to 70 knots.

I mentioned this late last week, and said a new TUTT would form around 20N 50W when Irene was south of PR.

I was wrong about Irene's location but the TUTT is very strong as seen on 200mb vorticity.

If the TUTT remains, Irene has an excellent chance to ramp to a major cane.

NHC is mentioning this as well in their latest discussion.

http://www.nhc.noaa.gov/text/refresh/MI ... 0859.shtml

Currently, the anticyclone is to the west, so intensification may be minimal until about 72W when Irene moves away from the Hispaniola coast.

I need to check details on the synoptic forecast to see how strong Irene gets before approaching the FL coast.

NHC is saying the models will maintain the outflow channels.

However, land interaction with FL will be critical especially the development of boundary-layer inversions (aka convective caps).







HURRICANE IRENE DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
500 AM AST MON AUG 22 2011


IT NOW APPEARS THAT IRENE WILL NOT INTERACT WITH HISPANIOLA AS MUCH
OR AS LONG AS PREVIOUSLY EXPECTED. THIS WILL ALSO RESULT IN MORE
STRENGTHENING THAN PREVIOUSLY EXPECTED. IRENE IS FORECAST BY ALL OF
THE MODELS TO HAVE A VERY IMPRESSIVE OUTFLOW PATTERN THROUGHOUT THE
FORECAST PERIOD...INCLUDING A LARGE UPPER-LEVEL TROUGH/LOW ABOUT
1200 NMI EAST OF THE CYCLONE ACTING AS A MASS SINK. WITH IRENE ALSO
EXPECTED TO BE OVER SSTS NEAR 30C AFTER 48 HOURS...SIGNIFICANT
STRENGTHENING COULD OCCUR. HOWEVER...THE OFFICIAL INTENSITY WILL
REMAIN ON THE CONSERVATIVE SIDE DUE TO THE UNCERTAINTY IN HOW MUCH
IRENE WILL INTERACT WITH THE MOUNTAINOUS TERRAIN OF HISPANIOLA FOR
THE NEXT 24-36 HOURS. THE OFFICIAL INTENSITY FORECAST IS A BLEND OF
THE SHIPS/LGEM MODELS AND THE HWRF/GFDL MODELS. HOWEVER...GIVEN THE
IMPRESSIVE UPPER-LEVEL FLOW PATTERN EXPECTED ACROSS IRENE...IT
WOULD NOT SURPRISE ME IF THIS CYCLONE BECAME A MAJOR HURRICANE AT
SOME TIME DURING ITS LIFETIME LIKE THE GFDL AND HWRF MODELS ARE
FORECASTING.


FORECASTER STEWART

[Gustywind]

Looks like PR is bandly experiencing Irene . Our thoughts go to Cycloneye. Hope that you're ok amigo, we're with you Luis!

Update:

TCUAT4

HURRICANE IRENE TROPICAL CYCLONE UPDATE...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
550 AM AST MON AUG 22 2011

CORRECTED TIME IN DATE/STIME HEADER

PRELIMINARY REPORTS INDICATE THAT WIDESPREAD TREE AND POWERLINE
DAMAGE HAS OCCURRED ON PUERTO RICO...AND MORE THAN 800 THOUSAND
HOMES ARE WITHOUT POWER ON THE ISLAND.

ALSO...FAA DOPPLER WEATHER RADAR INDICATES WINDS TO NEAR MAJOR
HURRICANE STRENGTH ARE NOW OCCURRING IN THE HIGHER ELEVATIONS OF
THE INTERIOR MOUNTAINOUS REGIONS OF PUERTO RICO.
$$
FORECASTER STEWART

[ronjon]

I'll be very interested to see some VDM's from Recon when they get back in there. The motion seems more NW than W or WNW to me right now. Could just be a wobble, but a wobble here and a wobble there will have big implications for us here in Florida down the road.

SFT

Radar showing a West heading.

PR RADAR

[vacanechaser]

I'll be very interested to see some VDM's from Recon when they get back in there. The motion seems more NW than W or WNW to me right now. Could just be a wobble, but a wobble here and a wobble there will have big implications for us here in Florida down the road.

SFT

Radar showing a West heading.

PR RADAR

looks more like a 280 heading to me.. not due west..



Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[ColinDelia]

ALSO...FAA DOPPLER WEATHER RADAR INDICATES WINDS TO NEAR MAJOR
HURRICANE STRENGTH ARE NOW OCCURRING IN THE HIGHER ELEVATIONS OF
THE INTERIOR MOUNTAINOUS REGIONS OF PUERTO RICO.

NEAR MAJOR? Is that an error?

[northjaxpro]

where is everyone we gotta hurricane on our hands. I know its a little early but thought the diehards would be up early to see what progress the storm made since last night lol

Good morning! I'm on here about to get ready to head to work. But, yes, Irene will likely grow into a major hurricane it appears becuase it looks as if my hunch since Saturday is going to pan out in that the storm will just barely skirt the northern coast of Hispaniola. It will have very little interaction with that island and it is looking more probable now that Irene may completely miss Cuba has she heads northwest in about 48 hours into the weakness. It will be a very tense week all along the SE U.S. Coast as we are potentially looking at a potentially severe tropical cyclone impacting somewhere. Irene will be getting to close to where I am here in Jax and it will be close enough that we will see impacts from her. It is just a question as to the severity of the impacts that have me rather concerned at this time.

[GCANE]

ADT was showing a RI starting about 6 hrs ago.

[Gustywind]

000
WTNT54 KNHC 220949
TCEAT4

HURRICANE IRENE TROPICAL CYCLONE POSITION ESTIMATE
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
600 AM AST MON AUG 22 2011

AT 600 AM AST...1000 UTC...THE CENTER OF HURRICANE
IRENE WAS ESTIMATED BY FAA DOPPLER WEATHER RADAR TO BE
NEAR LATITUDE 18.6 NORTH...LONGITUDE 66.6 WEST...OR ABOUT
40 MILES WEST-NORTHWEST OF SAN JUAN PUERTO RICO AND ABOUT
40 MILES EAST-NORTHEAST OF AGUADILLA PUERTO RICO.

SUMMARY OF 600 AM AST...1000 UTC...INFORMATION
--------------------------------------------------
LOCATION...18.6N 66.6W
ABOUT 40 MI...60 KM WNW OF SAN JUAN PUERTO RICO
ABOUT 40 MI...60 KM ENE OF AGUADILLA PUERTO RICO
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES

$$
FORECASTER STEWART

[Chacor]

ALSO...FAA DOPPLER WEATHER RADAR INDICATES WINDS TO NEAR MAJOR
HURRICANE STRENGTH ARE NOW OCCURRING IN THE HIGHER ELEVATIONS OF
THE INTERIOR MOUNTAINOUS REGIONS OF PUERTO RICO.

NEAR MAJOR? Is that an error?

Unlikely to be. Winds are generally stronger at higher elevations than at sea level.

[Emmett_Brown]

Hmm... looks like San Juan radar is not available at this time. Bummer, makes the eye more difficult to track, hope it comes up soon...

[fci]

ALSO...FAA DOPPLER WEATHER RADAR INDICATES WINDS TO NEAR MAJOR
HURRICANE STRENGTH ARE NOW OCCURRING IN THE HIGHER ELEVATIONS OF
THE INTERIOR MOUNTAINOUS REGIONS OF PUERTO RICO.

NEAR MAJOR? Is that an error?

There is a multiplier effect of winds at a higher elevation.

[GCANE]

MIMIC-TPW looks as good as UL outflow.

Infeed is well connected to the ITCZ with no dry-air intrusion.

TPW is in fact deepening around Irene's LLC, indicating the potential for strengthening.

If this pattern maintains itself as Irene gets close to the FL coast; new infeeds could develop from unstable-air over the Loop Current which would support strengthening.

[GCANE]

Irene will be hitting very high OHC water in about 72 hrs, equivalent to West Carib water.

[xironman]

Hmm... looks like San Juan radar is not available at this time. Bummer, makes the eye more difficult to track, hope it comes up soon...

You can use the FAA one

http://www.wunderground.com/radar/radblast.asp?ID=SJU&lat=0&lon=0&label=you&type=TR0&zoommode=pan&map.x=400&map.y=240&centerx=400&centery=240&prevzoom=zoom&num=10&delay=15&scale=1&showlabels=1&smooth=0&noclutter=0&showstorms=0&rainsnow=0&lightning=0

[summersquall]

Good morning all. Obviously very concerned with projected path and intensity - a cat 2 30 miles to my east.

Irene will be riding the warm gulfstream up the Florida peninsula on this track. The TVCN is even a little west
of the NHC path.

Local TV media is reporting accurately with very little hype. I sure hope we don't get a visit from Jim Cantore....have to go measure for plywood now.

Thoughts are with all those in Irene's path, today and in the coming days.

[GCANE]

Air going into the Bahamas looks decent with good moisture in the boundary-layer up to mid-level.

Expect for a little land interaction from Hispaniola, looks like there is nothing to slow Irene down.

In fact, need to watch if there will be any afternoon thunderstorms coming off Hispaniola which could act to further moisten mid-levels.

[CajunMama]

Just a reminder that if you post an image, especially a time sensitive image, please upload it before posting it. Refresh yourself with this thread....

Reminder About Posting Images

Thanks and now back to watching Irene!

[Chacor]

DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 700 AM AST...1100 UTC...DATA FROM THE SAN JUAN FAA DOPPLER
WEATHER RADAR INDICATE THAT THE CENTER OF HURRICANE IRENE WAS
LOCATED NORTH OF THE COAST OF PUERTO RICO NEAR LATITUDE 18.8
NORTH...LONGITUDE 66.8 WEST. IRENE IS MOVING TOWARD THE
WEST-NORTHWEST NEAR 14 MPH...22 KM/H. THIS GENERAL MOTION IS
EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF DAYS. ON THE FORECAST
TRACK THE CENTER OF IRENE WILL CONTINUE TO MOVE AWAY FROM THE NORTH
COAST OF PUERTO RICO THIS MORNING...AND APPROACH THE NORTHERN COAST
OF THE DOMINICAN REPUBLIC THIS AFTERNOON AND TONIGHT.