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Major Hurricane Irene live tracking


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You devalued your point with this image... the main source region is the belt of stronger winds east of Florida....that inflow is playing a much more significant role than the dry continental air...although I'll concede the dry continental air may be playing a small factor

*EDIT* additionally, the mid-level flow (where that dry air actually is) is *NOT* being advected towards Irene.

Thanks, that's what I thought.

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2 words...dry air.

Hypothesis...the SE/TX drought is going to be what prevents Irene from reaching her full potential.

Soil moisture and WV maps below.

I gotta wonder if the inflow now around Irene is tapping into the dry air, enhanced by drought over the Southeast and Texas. That's impressive dry air on WV imagery, and I have to think this is going to be the biggest limiting factor to Irene the next 24-48 hours. In other words, similar to how Don was probably choked by dry air off Texas, Irene may be feeling a similar impact now and is moving too slowly to really avoid it. Just a thought.

The WV image represents the moisture (and subsidence) in the middle and upper levels of the troposphere...so I am not sure how it relates to the inflow of the system...wouldn't the inflow be in the lower levels?

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post-357-0-15500700-1314385480.jpg

Note the narrow thin cirrus banding "spokes" emanating on both east and west sides- this often means that the cyclone may be getting ready for an attempt to strengthen- at the very least we may halt the weakening.

Thanks, always wondered what those things meant.

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Follow the wind barbs...where is the source region for the inflow to Irene?

Starts on land in the SE, travels over the Gulf across FL and in. It's clearly taking in dry air. It doesn't mean it won't hold its own or even strengthen again. But in my own opinion, dry air is going to hamper it. It's not manufacturing dry air...there's not much SAL around. I'm reasonably confident it's taking in dry air off a VERY dry landmass.

A static image of any wind field can be somewhat deceiving if you don't take into account storm motion. The important thing with respect to the tropical cyclone is whether there is storm-relative flow that is able to advect air in from the environment.

That said, the boundary-layer inflow is much, much stronger within the TC vortex itself as opposed to on the outer periphery. In addition, the air in the environment is being advected azimuthally around the vortex much more than inwards. Also, the boundary-layer flow within the TC is modified fairly quickly by the enthalpy fluxes from the ocean. All of these points suggest that the boundary-layer inflow hundreds to thousands of km away has a negligible impact on the TC vortex itself.

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NOUS41 KWBC 261844

PNSWSH

Service Change Notice 11-31

National Weather Service Headquarters Washington DC

245 PM EDT Fri Aug 26 2011

To: Subscribers:

-Family of Services

-NOAA Weather Wire Service

-Emergency Managers Weather Information Network

-NOAAPort

Other NWS partners and employees

From: La Tanya Burton

NWS EMWIN Program Manager

Subject: Hurricane Irene Emergency Outage for to EMWIN

and LRIT users Effective 13:00 EST, Saturday,

August 27, 2011

Effective 1550Z on Saturday through 2145Z on Sunday (approximately noon EDT Saturday through 6 pm EDT Sunday) there will be no Low-Rate Information Transmission (LRIT) data available from GOES West satellite (GOES 11). Due to the hurricane threatening Wallops, VA, and antenna issues, control of GOES-11 will be passed to the Fairbanks, AK, Command and Data Acquisition facility which does not have the capability to transmit LRIT data.

For users of GOES Data Collection System (DCS) there may also be issues with GOES DCS data from GOES West going into LRIT as well, although DCS data should be available through DOMSAT, through the NWS Telecommunications Gateway and GTS, and from the Emergency Data Distribution Network in South Dakota.

There also will not be any Emergency Managers Weather Information Network (EMWIN) data on GOES-West. EMWIN users pointed at GOES-West should switch to the EMWIN byteblaster network to receive EMWIN data during this time. GOES-East will remain broadcasting; however, should that broadcast go down due to the hurricane, please switch to the byteblaster network.

If you have questions or concerns about this notice, contact:

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The WV image represents the moisture (and subsidence) in the middle and upper levels of the troposphere...so I am not sure how it relates to the inflow of the system...wouldn't the inflow be in the lower levels?

http://weather.rap.u...=-1&duration=10

Time sensitive. Back at the beginning of the loop you can see that there was clearly an impingment on the SW side of the storm off the coast of Florida. That eventually got drawn into the storm and not long after it broke up a bit before starting to regather now.

We can break it down and figure out at what levels, and exactly what it was, but I have a hard time believing there was no association between that phenemona and what happened shortly after to Irene.

EDIT: I guess what I'm asking is if it wasn't shear what else could it have been. Whatever it was got wrapped in from SW and into the storm and had an immediate and detrimental effect on the structure and intensity. Appears it may be cycling out now but at the same time, the SW is looking like it did early this am.

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http://weather.rap.u...=-1&duration=10

Time sensitive. Back at the beginning of the loop you can see that there was clearly an impingment on the SW side of the storm off the coast of Florida. That eventually got drawn into the storm and not long after it broke up a bit before starting to regather now.

We can break it down and figure out at what levels, and exactly what it was, but I have a hard time believing there was no association between that phenemona and what happened shortly after to Irene.

EDIT: I guess what I'm asking is if it wasn't shear what else could it have been. Whatever it was got wrapped in from SW and into the storm and had an immediate and detrimental effect on the structure and intensity. Appears it may be cycling out now but at the same time, the SW is looking like it did early this am.

It is shear. The outflow in the southwest quad was/is being overwhelmed by the southwesterly flow in the upper-levels. The shear isn't super-strong, but it's enough to keep this at near steady state. You can see the impact the shear is having on the inner-core structure on the latest microwave posted by wxmx on the previous page...the convection is suppressed upshear.

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It is shear. The outflow in the southwest quad was/is being overwhelmed by the southwesterly flow in the upper-levels. The shear isn't super-strong, but it's enough to keep this at near steady state. You can see the impact the shear is having on the inner-core structure on the latest microwave posted by wxmx on the previous page...the convection is suppressed upshear.

Whis is disrupting the structure of the hurricane...makes sense thanks. Seems to be pulsing some and there appears to maybe be another pulse coming in from the SW. Looking at the water vapor after your explanation it makes sense seeing the higher cloud tops displaced well NE of the center as all of this was taking place this morning.

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Looks like she is really falling apart.

Not really. "falling apart" is too strong a term- will be interested to see what the pressure is when the plane gets there.

BTW, wave heights 24ft and rising 40 SE of Charleston:

http://www.ndbc.noaa.gov/station_page.php?station=41004

Even if this weakens a bit more, the large size will make it similar to Ike- that was "only" a 2 when it made landfall, but the wave setup and surge were above what you would expect with that category, I suspect the same with Irene. I still think that it may steady off before landfall, but further strengthening seems to not be in the cards, but these things can surprise you sometimes.

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We will see if she tries to strengthen. Hopefully people are heeding the warnings, and if she comes in weaker than anticipated, which may happen, hopefully they will not ignore warnings when the real big one comes. Regardless, even if just a cat 2 or 1 at landfall, this is going to be quite bad.

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We will see if she tries to strengthen. Hopefully people are heeding the warnings, and if she comes in weaker than anticipated, which may happen, hopefully they will not ignore warnings when the real big one comes. Regardless, even if just a cat 2 or 1 at landfall, this is going to be quite bad.

That is what I am afraid of. The worst case scenario is the one always presented to the public, and 9 out of 10 times it doesn't happen. Sooner or later it's going to happen but people won't listen because they feel the weather folks are crying wolf again.

I think this will be a real fail for the models if this goes to a Cat 1. Not that it would not still do damage, but some mets, even on here, were saying it would be a strong Cat 3 when it hit NC.

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That is what I am afraid of. The worst case scenario is the one always presented to the public, and 9 out of 10 times it doesn't happen. Sooner or later it's going to happen but people won't listen because they feel the weather folks are crying wolf again.

I think this will be a real fail for the models if this goes to a Cat 1. Not that it would not still do damage, but some mets, even on here, were saying it would be a strong Cat 3 when it hit NC.

I said the same thing. To be honest though, I don't know if there really is a worst case scenario for NYC, there obviously are claims that storms made landfall there in the past but we have no clue if they were hurricanes or just severe nor'easters (given the time of year they probably were hurricanes), but we also dont know the reliability of wind measurements back then or where the storm truly made landfall...the bottom line is a hurricane of any strength tracking over or barely east of NYC is quite remote and the more I think about it the emergency managament officials probably had no choice since the calls need to be made so far in advance.

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I said the same thing. To be honest though, I don't know if there really is a worst case scenario for NYC, there obviously are claims that storms made landfall there in the past but we have no clue if they were hurricanes or just severe nor'easters (given the time of year they probably were hurricanes), but we also dont know the reliability of wind measurements back then or where the storm truly made landfall...the bottom line is a hurricane of any strength tracking over or barely east of NYC is quite remote and the more I think about it the emergency managament officials probably had no choice since the calls need to be made so far in advance.

Something like August 1893 has been reasonably analyzed though-- it wasn't that far in the past to be relegated to obscurity lol.

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From the discussion

THE AIRCRAFT DID NOT FIND ANY HIGHER WINDS AFTER THE RELEASE OF THE

PREVIOUS ADVISORY. IN FACT...DATA FROM NEAR THE CONCLUSION OF THE

FLIGHT SUPPORT A SLIGHT LOWER INITIAL INTENSITY. THE AIRCRAFT DID

REPORT HURRICANE-FORCE WINDS AT FLIGHT LEVEL AND SFMR WINDS OF

50-55 KT 135 N MI EAST OF THE CENTER...SHOWING THE LARGE SIZE OF

THE WIND FIELD. BUOY OBSERVATIONS AND DATA FROM AN EARLIER ASCAT

PASS SHOW THAT THE TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD ABOUT

225-250 N MI OVER THE EASTERN SEMICIRCLE. RECENT MICROWAVE DATA AND

OBSERVATIONS FROM THE AIRCRAFT INDICATE THAT THE INNER CORE HAS

ERODED. ALTHOUGH IRENE WILL BE MOVING OVER WARM WATER DURING THE

NEXT 12-18 HOURS...THE LACK OF AN INNER CORE WILL LIKELY PRECLUDE

ANY RESTRENGTHENING. ALTHOUGH NOT SHOWN IN THE OFFICIAL

FORECAST...IRENE COULD WEAKEN JUST BELOW HURRICANE STRENGTH BEFORE

REACHING SOUTHERN NEW ENGLAND. HOWEVER...IMPACTS FROM THIS LARGE

TROPICAL CYCLONE WILL NOT BE VERY DIFFERENT IF IT IS A STRONG

TROPICAL STORM OR LOW-END HURRICANE. IRENE HAS THE POTENTIAL TO

PRODUCE DAMAGING WINDS...STORM SURGE FLOODING...AND EXTREMELY HEAVY

RAINS ALMOST ANYWHERE FROM EASTERN NORTH CAROLINA NORTHWARD THROUGH

NEW ENGLAND.

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Didn't quite pass the center, but last observation has 4kt winds so it is roughly there . Got some east of north movement since recon has been in there last, 077 deg 29 min W to roughly 077 deg 19 min W.  Extrap thus far is 950.1mb

951 on the official ob. I was going to edit the subtitle, but someone is faster than me. Maybe we'll see one last diurnal strengthening cycle. Or not.

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Wind radii and 12 foot seas continue to grow somewhat:

21Z advisory:

ESTIMATED MINIMUM CENTRAL PRESSURE 951 MB

MAX SUSTAINED WINDS 85 KT WITH GUSTS TO 105 KT.

64 KT....... 80NE 80SE 50SW 50NW.

50 KT.......140NE 125SE 80SW 90NW.

34 KT.......250NE 225SE 140SW 175NW.

12 FT SEAS..350NE 350SE 200SW 200NW.

15Z advisory:

ESTIMATED MINIMUM CENTRAL PRESSURE 946 MB

MAX SUSTAINED WINDS 90 KT WITH GUSTS TO 110 KT.

64 KT....... 80NE 80SE 50SW 50NW.

50 KT.......125NE 105SE 75SW 75NW.

34 KT.......250NE 200SE 130SW 175NW.

12 FT SEAS..330NE 330SE 180SW 210NW.

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