Major Hurricane Irene live tracking

[Chicago Storm]

Previous vortex message...new pass shortly.

Pressure of 950mb, an open eyewall, and max FL winds of 93kts in the NE quad.

New pass, NW/SE...

Pressure holding at 950mb and the eye wall is still open to the south.

URNT12 KNHC 251936

VORTEX DATA MESSAGE AL092011

A. 25/19:17:10Z

B. 26 deg 41 min N

077 deg 15 min W

C. 700 mb 2676 m

D. 70 kt

E. 305 deg 38 nm

F. 052 deg 73 kt

G. 307 deg 55 nm

H. 950 mb

I. 10 C / 3056 m

J. 17 C / 3045 m

K. 5 C / NA

L. Open S

M. C30

N. 12345 / 7

O. 0.02 / 1 nm

P. AF306 2109A IRENE OB 11

MAX FL WIND 92 KT NE QUAD 18:11:10Z

MAX OUTBOUND FL WIND 99 KT SE QUAD 19:26:30Z

Clouds below in center, sfc cntr not visible

Max SWS outbound 74kts 19:28:30Z SE Quad

[IsentropicLift]

Over the past 3-4 hours there has been a big burst of deep convection that first flarred up on the NE side and has now wrapped around the western side of the circulation. It's looking much more healthy overall.

[dan88]

Down to just open south, last remaining part of the eye to close (see microwave image for earlier where it has 25% to go.

Recon shows the much improved structure, but winds have yet to respond, below is the most recent leg of the recon, from center to SE quad. Note that from the center, there is no sign of an inner eyewall max, but on either side of the new eyewall max, there is only a gradual change in winds. This is a sign that Irene now has the structure needed to intensify, but the winds are lagging this increase in organization. From now, if Irene can take advantage of it's structure, there should be a sharp increase in winds in the new eyewall, and the smoothness up until the wind max should be replaced by a sharp gradient around the wind max to slower winds outside of the eyewall.

191700 2641N 07715W 6957 02729 9504 +155 +061 007003 007 028 001 00 
191730 2640N 07713W 6969 02709 9502 +155 +063 239007 008 021 001 00  Rough location of center
191800 2639N 07711W 6961 02718 9502 +152 +066 229015 017 025 001 00
191830 2638N 07710W 6967 02712 9504 +151 +066 229022 024 031 003 00
191900 2637N 07708W 6962 02723 9506 +153 +068 228027 029 030 000 03 Gradual increase in winds, but no eyewall inner max
191930 2636N 07706W 6970 02716 9508 +154 +069 222043 046 035 000 00
192000 2636N 07704W 6969 02724 9509 +161 +070 221052 056 046 002 03
192030 2635N 07702W 6963 02742 9532 +151 +071 224061 062 052 001 03
192100 2633N 07702W 6962 02754 9544 +150 +071 227061 061 /// /// 03
192130 2632N 07702W 6969 02753 9556 +146 +072 236071 075 /// /// 03
192200 2631N 07701W 6967 02768 9571 +144 +071 236076 077 059 001 03
192230 2629N 07700W 6969 02782 9606 +125 +070 235080 082 /// /// 03 
192300 2628N 07659W 6969 02797 9622 +126 +068 234082 083 072 001 03
192330 2627N 07657W 6969 02813 9624 +140 +066 232082 083 072 003 00
192400 2625N 07656W 6963 02835 9639 +142 +066 230088 089 074 001 03
192430 2624N 07655W 6969 02839 9659 +134 +066 230090 091 070 000 03
192500 2623N 07653W 6962 02861 9680 +129 +066 231092 093 068 000 03
192530 2622N 07652W 6967 02865 9696 +125 +066 231094 096 069 001 03
192600 2620N 07651W 6970 02872 9706 +125 +066 232097 097 068 001 00
192630 2619N 07649W 6972 02879 9721 +123 +066 232098 099 067 003 00  Peak winds, surrounded by similar strength winds
192700 2618N 07648W 6967 02895 9739 +115 +065 232097 098 069 004 00
192730 2617N 07647W 6967 02903 9754 +110 +065 231097 098 071 003 00
192800 2616N 07645W 6972 02907 9769 +105 +064 232096 097 074 005 00
192830 2614N 07644W 6970 02918 9776 +109 +062 232094 095 074 005 00
192900 2613N 07643W 6966 02933 9789 +106 +061 232093 093 073 004 00
192930 2612N 07641W 6966 02943 9796 +110 +059 231095 096 074 003 00
193000 2611N 07640W 6968 02946 9806 +107 +058 228095 096 072 001 00
193030 2610N 07639W 6964 02959 9808 +112 +058 227093 094 070 004 00
193100 2608N 07638W 6967 02959 9813 +114 +057 227092 094 069 000 03
193130 2607N 07636W 6969 02967 9824 +111 +058 229092 094 067 001 03
193200 2606N 07635W 6968 02976 9835 +110 +058 228090 091 067 004 03
193230 2605N 07634W 6967 02979 9848 +103 +057 225087 088 067 005 00
193300 2604N 07632W 6969 02988 9877 +084 +056 224087 088 065 009 00
193330 2603N 07631W 6960 03002 9874 +091 +054 223087 088 064 013 00
193400 2601N 07630W 6961 03001 9876 +093 +052 228085 087 065 009 00
193430 2600N 07629W 6970 02999 9876 +099 +051 228083 084 064 007 00
193500 2559N 07627W 6967 03007 9882 +100 +050 227084 086 063 007 00  

[Eskimo Joe]

Water Vapor loop says it all. Overall increase in diameter of the storm, cooling cloud tops and more symmetrical appearance near the core. Definite signs of strengthening.

http://www.ssd.noaa.gov/goes/flt/t2/flash-wv.html

[Chicago Storm]

Pressure has been slowly falling during the time recon has been out...

Latest VDM showing 947mb pressure, with the southern portion of the eyewall still open.

The other mission out there had 111kt FL wind a bit earlier.

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

[Maximum lawman]

Pressure has been slowly falling during the time recon has been out...

Latest VDM showing 947mb pressure, with the southern portion of the eye wall still open.

The other mission out there had 111kt FL wind a bit earlier.

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

When was this fix? It's a little confusing around here.

[dan88]

6:11pm Microwave shows the eyewall closing, though most recent vortex is still saying that the eyewall is open South. Winds have yet to respond, but pressure estimate down to 946mb on the advisory. Latest IR showed part of the eye was exposed for a bit, but now getting warming of the full eye, along with cooling of the Western eyewall and with a new cell in the Northern eyewall

[Chicago Storm]

When was this fix? It's a little confusing around here.

7:06PM EDT.

[Ed Lizard]

Mt. Holly/Philadelphia had an interesting point about the upper level jet possibly putting Irene in an entrance region and delaying weakening more than would be expected based on land interactions and cooler SSTs.

[LakeEffectKing]

IR is giving us hints to the size of the new eye:

[bobbutts]

IR is giving us hints to the size of the new eye:

Nice progress in 30 minutes

[Bobby]

Here she goes boys....Looking better every minute.

[phil882]

I agree that this storm is strengthening... we have a 6-12 hour window for this storm to become better organized and intensify until the inner eyewall starts to collapse... the problem is the EWRC will begin when the shear is expected to increase so we will likely experience a more significant drop in the max winds after this initial peak in the next 6-12 hours.

[Riptide]

I agree that this storm is strengthening... we have a 6-12 hour window for this storm to become better organized and intensify until the inner eyewall starts to collapse... the problem is the EWRC will begin when the shear is expected to increase so we will likely experience a more significant drop in the max winds after this initial peak in the next 6-12 hours.

It's widely accepted that EWRCs do not follow periodic cycles and are largely unpredictable, wouldn't count on that as a saving grace...

[SACRUS]

I agree that this storm is strengthening... we have a 6-12 hour window for this storm to become better organized and intensify until the inner eyewall starts to collapse... the problem is the EWRC will begin when the shear is expected to increase so we will likely experience a more significant drop in the max winds after this initial peak in the next 6-12 hours.

Yes and 6 - 12 hours over some good fuel as well.

[HKY_WX]

The eye looks pretty much symmetrical and rounded on grl3 long range from Melbourne. I think we're just seeing some high clouds over the eye on IR. Once those deteriorate the eye should clear out. I would wager the morning visible will look incredible.

[WeatherNC]

I agree that this storm is strengthening... we have a 6-12 hour window for this storm to become better organized and intensify until the inner eyewall starts to collapse... the problem is the EWRC will begin when the shear is expected to increase so we will likely experience a more significant drop in the max winds after this initial peak in the next 6-12 hours.

I agree for the most part, however, OF looks great in all quadrants and the CDO is under very low shear currently. Yes the RI probs are low, but we are already talking abut a storm in the mid 940's, so >20mb drop seems unlikely. That window should be extended imo, 12-24 hrs, and depending on how big the eventual inner max becomes, will go a long way in hammering out the intensity prior to landfall. Some of the guidance, namely the GFS and EC, has been consistent in strengthening this storm north of 30. Irene is now inside the shelf, and for one of the first times in recent memory, clear of terrain influence, and weakening shear.

[Shawn]

The eye looks pretty much symmetrical and rounded on grl3 long range from Melbourne. I think we're just seeing some high clouds over the eye on IR. Once those deteriorate the eye should clear out. I would wager the morning visible will look incredible.

GRLEVEL2 , 8/25/11 - 8:56PM EST:

[wxsmwhrms]

Mt. Holly/Philadelphia had an interesting point about the upper level jet possibly putting Irene in an entrance region and delaying weakening more than would be expected based on land interactions and cooler SSTs.

Yeah, the models have been showing that for a few days now. That is probably one of the reasons why the models keep the pressures as low as they do N of NC. I haven't looked at it in detail today, but there is also some chance that latent heat release associated with the hurricane is helping strengthen the jet downstream, at least in the model, resulting in a kind of feedback effect. How all this plays out in the real atmosphere remains to be seen, of course.

[Scott747]

Yes and 6 - 12 hours over some good fuel as well.

It was plenty of fuel till Carolina -

[CUmet]

I agree that this storm is strengthening... we have a 6-12 hour window for this storm to become better organized and intensify until the inner eyewall starts to collapse... the problem is the EWRC will begin when the shear is expected to increase so we will likely experience a more significant drop in the max winds after this initial peak in the next 6-12 hours.

I'm not expecting the shear to have a significant impact until Friday evening, when the 200 mb flow in the southwest quad shifts to southwesterly and increases in magnitude. There appears to be a window between Friday evening-Saturday morning where some weakening is likely. Afterwards, although the SHIPS-diagnosed shear off the GFS increases in magnitude, the outflow channel greatly increases in magnitude, acting to offset this. Another factor to consider is the Gulf Stream, which may also counteract the shear.

[phil882]

It's widely accepted that EWRCs do not follow periodic cycles and are largely unpredictable, wouldn't count on that as a saving grace...

Of course... but I am basing this on the current presentation which already shows a developing moat, along with the expected increase in southwesterly shear before landfall. I'm working on a blog update and should have my thoughts in more detail in the next hour.

[LakeEffectKing]

IR says CLOSED OFF!!

[dan88]

extra 943.7mb from 750mb, 80kt W quad, 100kt E quad. Worth noting that the gradient between the eyewall and outside on both sides was steeper than before in the West quad at least (haven't seen E quad yet much past max, but it is a sharper gradient from calm to max then earlier. )Heavy convection in the East eyewall, up to 44mm/hr rainfall rates.<br>

[wxsmwhrms]

IR says CLOSED OFF!! 

Wow, that IR presentation became pretty darn impressive very quickly. Very cold tops N/NW of eye.

[LakeEffectKing]

I promise not to post every frame of the IR, but the improvement in the last hour warrants it, IMO...

[dan88]

Haven't seen a center drop yet for the last pass, but there was a west eyewall drop, spashed with 60kt winds and a pressure of 950mb, so pressure is likely dropping from the 946 estimate by the last recon pass.

[wxsmwhrms]

I promise not to post every frame of the IR, but the improvement in the last hour warrants it, IMO...

KMLB radar is showing 35 dBZ returns in the NW eyewall. Pretty impressive considering we're talking 200+ miles away, and other bands are between the radar and the eye.

[dan88]

Doesn't look like there is a center drop unfortunately, but there was an east eyewall drop of 950mb with 70kt winds at the surface, so it is almost surely down from the 946mb estimate with the last pass. Ended up with 101kt on the east wall, but still not a sharp gradient East of the East eyewall max (holds near the max for a ways past the max).<br>

[ALhurricane]

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.