Major Hurricane Irene live tracking

[WeatherNC]

What is interesting to me is that even with the continued pressure drop, FL winds and SFMR really do not support a 100 kt intensity. This is likely due to the expansion of the wind field during the ERC. Now I am not saying the NHC should drop the intensity, but that is what recon is showing at this time, unless I missed a set of obs.

Spot on AL, but given the slp, and radia, likely a decision that was warranted given impact to the N and current presentation.

[LakeEffectKing]

What is interesting to me is that even with the continued pressure drop, FL winds and SFMR really do not support a 100 kt intensity. This is likely due to the expansion of the wind field during the ERC. Now I am not saying the NHC should drop the intensity, but that is what recon is showing at this time, unless I missed a set of obs.

They did measure a 100kt FL wind...and I kind of agree with you...however, and I could very well be off base, but the media surely would mention the weakening from a cat 3 to a 2....and really, based on the overall hazard with this system, and potential, they may just "fudge" their objectivenss a little bit to keep people on alert....not to mention, this really could still tighten up a bit....but much like we waited for Ike to gather itself, it really ended up being a inner storm within a large cyclonic gyre in a semi-steady state.....and that is a possibility here as well with the expanded wind field.

000

URNT12 KNHC 252337

VORTEX DATA MESSAGE AL092011

A. 25/23:06:10Z

B. 27 deg 28 min N

077 deg 20 min W

C. 700 mb 2629 m

D. 76 kt

E. 114 deg 17 nm

F. 205 deg 87 kt

G. 126 deg 55 nm

H. 947 mb

I. 8 C / 3046 m

J. 16 C / 3045 m

K. 6 C / NA

L. OPEN S

M. C25

N. 12345 / 07

O. 0.02 / 1 nm

P. AF306 2109A IRENE OB 21

MAX FL WIND 100 KT NE QUAD 20:52:20Z

MAX OUTBOUND FL WIND 91 KT NW QUAD 23:12:10Z

[Thundersnow12]

[dan88]

They did measure a 100kt FL wind...and I kind of agree with you...however, and I could very well be off base, but the media surely would mention the weakening from a cat 3 to a 2....and really, based on the overall hazard with this system, and potential, they may just "fudge" their objectivenss a little bit to keep people on alert....not to mention, this really could still tighten up a bit....but much like we waited for Ike to gather itself, it really ended up being a inner storm within a large cyclonic gyre in a semi-steady state.....and that is a possibility here as well with the expanded wind field.

Earlier there was a 111kt flight level observation from the NOAA plane as well, but that's from 750mb where the surface ratio is less than the typically used estimate of 90% at 700mb, and was only accompanied by 87kt from the SFMR.

[blueheronNC]

They did measure a 100kt FL wind...and I kind of agree with you...however, and I could very well be off base, but the media surely would mention the weakening from a cat 3 to a 2....and really, based on the overall hazard with this system, and potential, they may just "fudge" their objectivenss a little bit to keep people on alert....not to mention, this really could still tighten up a bit....but much like we waited for Ike to gather itself, it really ended up being a inner storm within a large cyclonic gyre in a semi-steady state.....and that is a possibility here as well with the expanded wind field.

Classifying it as a Cat 2 can wait until the best track.

[gkrangers]

How much do sustained winds rely on smooth momentum in a hurricane? Irene has been going through structural changes all day, which I would imagine would make attaining higher wind speeds difficult.

I'd be shocked not to see winds pickup over the next few hours...as it appears the structure may be more sound, more fluid.

[janetjanet998]

What is interesting to me is that even with the continued pressure drop, FL winds and SFMR really do not support a 100 kt intensity. This is likely due to the expansion of the wind field during the ERC. Now I am not saying the NHC should drop the intensity, but that is what recon is showing at this time, unless I missed a set of obs.

plus the fact it was a large storm even before the ERC and getting even larger now..takes time to ramp up..on the flip side becuase of it's size it will likely take longer to ramp down too once it moves inland and/or north of the gulf stream off of NC Irene has cleared the higher ocean heat content and SST lower to about 28.5ish from here(actually a little east of the gulf stream attm) until the gulfstream more north(back to 30C there) looking better

[ALhurricane]

They did measure a 100kt FL wind...and I kind of agree with you...however, and I could very well be off base, but the media surely would mention the weakening from a cat 3 to a 2....and really, based on the overall hazard with this system, and potential, they may just "fudge" their objectivenss a little bit to keep people on alert....not to mention, this really could still tighten up a bit....but much like we waited for Ike to gather itself, it really ended up being a inner storm within a large cyclonic gyre in a semi-steady state.....and that is a possibility here as well with the expanded wind field.

000

URNT12 KNHC 252337

VORTEX DATA MESSAGE AL092011

A. 25/23:06:10Z

B. 27 deg 28 min N

077 deg 20 min W

C. 700 mb 2629 m

D. 76 kt

E. 114 deg 17 nm

F. 205 deg 87 kt

G. 126 deg 55 nm

H. 947 mb

I. 8 C / 3046 m

J. 16 C / 3045 m

K. 6 C / NA

L. OPEN S

M. C25

N. 12345 / 07

O. 0.02 / 1 nm

P. AF306 2109A IRENE OB 21

MAX FL WIND 100 KT NE QUAD 20:52:20Z

MAX OUTBOUND FL WIND 91 KT NW QUAD 23:12:10Z

I agree with you. It would definitely send the wrong message to downgrade right now given the satellite presentation. However given the wind field has become so broad, I too think we may me looking at a storm that may not be able to strengthen too much more.

[SN_Lover]

TWC is showing 32 foot waves from Irene. TWC also says that dry air is filtering in to the northwest quadrant of Irene from Jacksonville.

[k***]

plus the fact it was a large storm even before the ERC and getting even larger now..takes time to ramp up..on the flip side becuase of it's size it will likely take longer to ramp down too once it moves inland and/or north of the gulf stream off of NC Irene has cleared the higher ocean heat content and SST lower to about 28.5ish from here(actually a little east of the gulf stream) until the gulfstream(back to 30 there) looking better

I just cant look past that giant stable area/moat/whatever on the west side. It's game over if that inner eyewall is perturbed.

[phil882]

What is interesting to me is that even with the continued pressure drop, FL winds and SFMR really do not support a 100 kt intensity. This is likely due to the expansion of the wind field during the ERC. Now I am not saying the NHC should drop the intensity, but that is what recon is showing at this time, unless I missed a set of obs.

NOAA plane measured 110+ knot winds in one of its NE passes, so this is still a legit 3 given these winds. However, I agree with you, this storm is using the warm water to expand its winds further rather than increase its maximum sustained winds, although more recently in the last 3-4 hours it shows that its also trying to tighten up its core somewhat.

[yoda]

00z NAM through 24 looks faster then 18z using the h5 charts as comparison

[wxsmwhrms]

I just cant look past that giant stable area/moat/whatever on the west side. It's game over if that inner eyewall is perturbed.

The interesting thing about that is that the NW side of the CDO is the more impressive side as far as size and coldness of tops, even as beyond that the NW side looks eroded. The inner core definitely looks as impressive as it has in quite some time, fairly warm eye completely ringed by colder tops.

[ALhurricane]

NOAA plane measured 110+ knot winds in one of its NE passes, so this is still a legit 3 given these winds. However, I agree with you, this storm is using the warm water to expand its winds further rather than increase its maximum sustained winds, although more recently in the last 3-4 hours it shows that its also trying to tighten up its core somewhat.

I just found that myself. Thanks for pointing it out. Even with the 110 kt ob, the SFMR was only 73 kt. I think the highest SFMR I have seen recently is around 90 kt. Something is preventng the full transport of the FL winds to the sfc.

Again, I could have missed a higher reading, I am in the middle of a string of midnight shifts and the brain is not working at full capacity.

[wxsmwhrms]

Just to show that the subjective comments we have been making about the IR presentation have some objective support as well, ADT numbers have been going up again this evening:

UW - CIMSS ADVANCED DVORAK TECHNIQUE ADT-Version 8.1.3 Tropical Cyclone Intensity Algorithm ----- Current Analysis ----- Date : 26 AUG 2011 Time : 011500 UTC Lat : 27:32:52 N Lon : 77:15:32 W CI# /Pressure/ Vmax 5.7 / 945.5mb/107.2kt Final T# Adj T# Raw T# 5.7 5.7 5.7 Estimated radius of max. wind based on IR : 11 km Center Temp : -28.5C Cloud Region Temp : -66.3C Scene Type : EYE Positioning Method : SPIRAL ANALYSIS Ocean Basin : ATLANTIC Dvorak CI > MSLP Conversion Used : ATLANTIC Tno/CI Rules : Constraint Limits : NO LIMIT Weakening Flag : OFF Rapid Dissipation Flag : OFF C/K/Z MSLP Estimate Inputs : - Average 34 knot radii : 183km - Environmental MSLP : 1010mb Satellite Viewing Angle : 32.2 degrees ****************************************************

[dan88]

99kt NE quad, extrap, somewhat weird 937.2mb NE of the center, 942.1 closer to the center.

015400 2803N 07710W 7516 02133 9580 +171 //// 128095 099 074 017 01
015430 2802N 07712W 7515 02107 9548 +176 +177 122093 095 077 025 00
015500 2801N 07713W 7499 02092 9513 +176 +178 116088 095 081 033 00
015530 2759N 07715W 7498 02066 9473 +184 //// 117069 080 084 021 05
015600 2757N 07716W 7524 02017 9433 +191 //// 121051 055 058 003 05
015630 2756N 07718W 7527 02001 9391 +197 //// 127035 039 036 002 01
015700 2754N 07719W 7529 01990 9372 +198 //// 130022 026 024 000 01
015730 2752N 07720W 7538 01981 9406 +203 +182 107018 020 019 000 03
015800 2750N 07721W 7535 01979 9423 +201 +176 102004 005 018 000 03
015830 2748N 07721W 7516 02002 9421 +203 +164 267004 007 019 000 00

[dan88]

955mb/91kt surface wind drop in the NE quad

[blazess556]

942 mb in eye from dropsonde.

[phil882]

942 mb in eye from dropsonde.

The eyewall on radar continues to become better defined... I'd say its a better indicator of organization than enhanced IR at this point, although the IR presentation continues to improve as well.

The problem is we have FL winds of 90-95 knots nearly 100 miles away from the circulation center. What the storm has been doing is broadening its entire wind field rather than intensifying the winds closer to the core. However, there is some evidence that is changing, because the latest NOAA plane measured 100 knot winds very close to the center in the last pass (10 or so miles away)... 2-3 hours ago the 100 knot winds were located a good 40 miles form the center. The core is redeveloping per this data.

[DAWGNKITTEN]

http://radar.weather.gov/radar.php?product=N0Z&rid=mlb&loop=yes

Just wondering if anyone else thinks this looks stationary...or have I been looking at it too long?

[LakeEffectKing]

The eyewall on radar continues to become better defined... I'd say its a better indicator of organization than enhanced IR at this point, although the IR presentation continues to improve as well.

The problem is we have FL winds of 90-95 knots nearly 100 miles away from the circulation center. What the storm has been doing is broadening its entire wind field rather than intensifying the winds closer to the core. However, there is some evidence that is changing, because the latest NOAA plane measured 100 knot winds very close to the center in the last pass (10 or so miles away)... 2-3 hours ago the 100 knot winds were located a good 40 miles form the center. The core is redeveloping per this data.

Yeah, the last image of IR would make one think this is going to really get going and become a "punchole" eye and generally in that state, you have a minimum of a high cat 3/low cat 4.....but those outer winds just don't sit well with rapid intensification....The eye appears quite small from what I'd have gathered it would look like just a couple hours ago....so maybe the winds are in fact contracting....

[CUmet]

The interesting thing about that is that the NW side of the CDO is the more impressive side as far as size and coldness of tops, even as beyond that the NW side looks eroded. The inner core definitely looks as impressive as it has in quite some time, fairly warm eye completely ringed by colder tops.

This is probably a response to the shear. The earlier microwave pass indicated the strongest convection in the NE quad, and as the updraft travels counterclockwise around the center, the coldest cloud tops appear on the northwest quad. However, on radar it appears that the eye has closed and has become much more symmetrical over the past 6 hours, indicative of either decreasing shear or an increase in the vortex's resilience to it.

[hm8]

What would be worse for the NE in the long run though....a larger wind field but weaker maximum intensity, or a smaller but more intense storm?

[dan88]

New eye still opened SW.

000

URNT12 KWBC 260216

VORTEX DATA MESSAGE

A. 26/0158Z

B. 27 DEG 49 MIN N

77 DEG 21 MIN W

C. NA

D. 82 KT

E. 031 DEG 13 NM

F. 128 DEG 99 KT

G. 035 DEG 18 NM

H. 942 MB

I. 17 C/2445 M

J. 21 C/2440 M

K. 16 C/NA

L. OPEN SW

M. C 25

N. 12345/NA

O. 1/1 NM

P. NOAA2 2309A IRENE OB 36 AL092011

MAX FL WIND 111KT NE QUAD 2125Z

[andyhb]

What would be worse for the NE in the long run though....a larger wind field but weaker maximum intensity, or a smaller but more intense storm?

Larger storm would probably give you more storm surge.

[wxsmwhrms]

This is probably a response to the shear. The earlier microwave pass indicated the strongest convection in the NE quad, and as the updraft travels counterclockwise around the center, the coldest cloud tops appear on the northwest quad. However, on radar it appears that the eye has closed and has become much more symmetrical over the past 6 hours, indicative of either decreasing shear or an increase in the vortex's resilience to it.

Makes sense. Sure is looking impressive on IR now. Down 8 mb since last advisory...

[bobbutts]

drastic improvement in radar presentation in the last 1.5 hr

she's looking good even on KAMX

9:14

10:42

[Thunder Road]

Larger storm would probably give you more storm surge.

That's what I was thinking. The bigger problem right now is surge, most homes can handle 85 mph winds with just shingles/windows gone

[Thunder Road]

Anyway 11 pm advisory keeps it at 100 kt, drops pressure to 942 mb.

[phil882]

Looking great on IR as well now.