Current Radar or Satellite Image

Flhurricane.com - Central Florida Hurricane CenterHurricanes Without the Hype! Since 1995


Azores #96L fails to complete transition into a Sub-Tropical Storm. Elsewhere, weak low pressure in Caribbean may linger into next week.
Days since last H. Landfall - US: Any 45 (Nate) , Major: 62 (Maria) Florida - Any: 72 (Irma) Major: 72 (Irma)
None
COMMUNICATION
STORM DATA
CONTENT
FOLLOW US
ADS
Login to remove ads

 


Archives >> 2011 News Talkbacks

Jump to first unread post. Pages: 1 | 2 | (show all)
Random Chaos
Weather Analyst


Reged: Sat
Posts: 1023
Loc: Maryland 38.98N 76.50W
Re: Hurricane Irene Landfalls at Cape Lookout, NC [Re: danielw]
      #91994 - Sat Aug 27 2011 06:23 PM

From NHC 5pm discussion:

MORE SO THAN WITH MOST STORMS...THE WINDS WITH IRENE INCREASE
SHARPLY WITH HEIGHT ABOVE THE SURFACE. AS IRENE MOVES THROUGH
AREAS WITH HIGH-RISE STRUCTURES...THESE STRUCTURES WILL EXPERIENCE
WINDS SIGNIFICANTLY STRONGER THAN INDICATED BY THE ADVISORY
INTENSITY. WINDS AT THE 30-STORY LEVEL WILL LIKELY BE 20 PERCENT
HIGHER THAN AT THE SURFACE...AND WINDS 80-100 STORIES UP COULD BE
ABOUT 30 PERCENT HIGHER THAN AT THE SURFACE.


Post Extras: Print Post   Remind Me!   Notify Moderator  
MikeCAdministrator
Admin


Reged: Sun
Posts: 3888
Loc: Orlando, FL 28.49N 81.47W
Re: Hurricane Irene Landfalls at Cape Lookout, NC [Re: Random Chaos]
      #91995 - Sat Aug 27 2011 06:25 PM

And from just now



Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3502
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: Hurricane Irene Landfalls at Cape Lookout, NC [Re: MikeC]
      #91996 - Sat Aug 27 2011 06:52 PM

I'm estimating that at a 1 foot rise per hour. Or more.

Post Extras: Print Post   Remind Me!   Notify Moderator  
cieldumort
Moderator


Reged: Mon
Posts: 1635
Loc: Austin, Tx 30.40N 97.80W
Re: Hurricane Irene Landfalls at Cape Lookout, NC [Re: danielw]
      #91997 - Sat Aug 27 2011 07:09 PM

1 Ft every couple of minutes of storm surge currently (live stream, time sensitive)

(LINK)


Edit: Hurricanetrack has estimated a total of six feet over two hours

Edited by cieldumort (Sat Aug 27 2011 07:12 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Random Chaos
Weather Analyst


Reged: Sat
Posts: 1023
Loc: Maryland 38.98N 76.50W
Re: Hurricane Irene Landfalls at Cape Lookout, NC [Re: cieldumort]
      #91998 - Sat Aug 27 2011 07:18 PM

Currently they are near Nags Head. Exact location: http://www.hurricanetrack.com/map/


Chesapeake Bay near Sandy Point State Park (just north of Annapolis):


Edited by Random Chaos (Sat Aug 27 2011 07:36 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
WeatherNut
Weather Master


Reged: Wed
Posts: 412
Loc: Atlanta, GA 33.81N 84.34W
Re: Hurricane Irene Landfalls at Cape Lookout, NC [Re: Random Chaos]
      #91999 - Sat Aug 27 2011 08:01 PM

That 950 pressure reading has me concerned. I dont recall a Cat1 ever having a pressure reading that low. Is it possible that baroclinic influences have started to act on Irene? Also, wont a low pressure increase the surge?

--------------------
Born into Cleo (64)...been stuck on em ever since


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3502
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: Hurricane Irene Landfalls at Cape Lookout, NC [Re: WeatherNut]
      #92000 - Sat Aug 27 2011 08:15 PM Attachment (264 downloads)

I would think the low pressure would increase the surge. It has in other storms.

Using deltaP of 1013 minus mcp (current) 950 mb = 63/ 4= a possible surge height of 15.75 feet

(Formula has not been peer reviewed. But has been checked against many hurricanes from Category 1 up.
Formula was within a +/- 1 foot margin for Katina's high Water Marks~danielw)

This doesn't mean Irene will produce a 15.75 foot surge. It suggest Irene is capable of generating a surge to that limit.

Note: I have attached a jpeg of a spreadsheet that I developed a few years ago for calculating or estimating Storm Parameters, called HurriSheet. Some of the formulas are used by Meterologists the others are simple variations of their formulas. A+B=C/ D type formulas.~danielw

Edited by danielw (Sat Aug 27 2011 08:21 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
cieldumort
Moderator


Reged: Mon
Posts: 1635
Loc: Austin, Tx 30.40N 97.80W
Re: Hurricane Irene Landfalls at Cape Lookout, NC [Re: WeatherNut]
      #92001 - Sat Aug 27 2011 08:22 PM

Quote:

That 950 pressure reading has me concerned. I dont recall a Cat1 ever having a pressure reading that low. Is it possible that baroclinic influences have started to act on Irene? Also, wont a low pressure increase the surge?




While baroclinic influences have been underway, these are not the only, even primary, reason for Irene's relatively very low pressure. Recall that Ike as a Cat 2 also had very low pressure (also about 950mb, in fact). Extra large and powerful hurricanes do not always end up concentrating their force within the core, and such has been the case with Irene, in many ways much as it had been with Ike.

This lower pressure is helping result in higher-than-usual surge for the given Saffir-Simpson category. It is important to note that the Saffir-Simpson scale is a wind scale, only. The NHC has dropped suggesting any relation to surge, pressure, anything else, other than wind. However, if one wants to relate the current overall intensity of Irene to the old SS scale, 950mb would have lined up with Category 3.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)



Extra information
0 registered and 0 anonymous users are browsing this forum.

Moderator:  MikeC, Ed Dunham, danielw 

Print Topic

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled

Rating:
Topic views: 15869

Rate this topic

Jump to

Note: This is NOT an official page. It is run by weather hobbyists and should not be used as a replacement for official sources. 
CFHC's main servers are currently located at
Hostdime.com in Orlando, FL.
Image Server Network thanks to Mike Potts and Amazon Web Services. If you have static file hosting space that allows dns aliasing contact us to help out! Some Maps Provided by:
Great thanks to all who donated and everyone who uses the site as well. Site designed for 800x600+ resolution
When in doubt, take the word of the National Hurricane Center