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Major Hurricane Irene live tracking


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Re RI: I suspect the higher winds on the last pass has a lot more to do with the strong convection than actual deepening of the storm itself.

Question - Are you suggesting that after that burst of convection ceases such rapid development the winds will drop back down? Not so sure NHC would have bumped up so much if it was temporary - I may be misunderstanding what you are saying, though.

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Re RI: I suspect the higher winds on the last pass has a lot more to do with the strong convection than actual deepening of the storm itself.

Which are not perfectly separate issues, as a cyclone's intensity is expressed in terms of max winds, and those max winds are usually the result of core convection mixing the high-speed flow to the surface.

I'm not saying it's doing RI-- the whole conversation is silly-- but distinguishing between 1) a system's "representative" winds and 2) "localized, non-representative" winds is a big, messy topic.

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Which are not perfectly separate issues, as a cyclone's max winds are usually the result of core convection mixing the high-speed flow to the surface.

I'm not saying it's doing RI-- the whole conversation is silly-- but distinguishing between a system's "representative" winds and "localized, non-representative" winds is a big, messy topic.

RI is one of those things that we tend to catch mid-phase anyway. A couple hours from now or early tomorrow morning we could be looking back and saying, "Yeah, it is undergoing RI." Or maybe not.

Not something easily declared until it is well underway. Regardless, it is strengthening.

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While the impacts of the gulfstream dropsondes this afternoon are important, I'm actually more interested in the impact of the next several sets of Pacific Northwest soundings. The evolution of the northern stream flow will have just as much impact on the future track of Irene as the evolution of the subtropical ridge, and the important shortwaves are just beginning to move into the North American RAOB network. It I had my way, I'd want an aircraft dropping sondes over the eastern pacific to get a better grasp on the northern stream flow.

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Will be getting a 700mb pass of the NE quad next update, but got the center this time. Extrap pressure isn't there, but got the center location. Net gain looks to be about 8 minutes north (.133 lattitude), and 15 min West (.25 lattitude).

It is up to 19.85N now, which is getting very close to the northern most point of Hispaniola.

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While the impacts of the gulfstream dropsondes this afternoon are important, I'm actually more interested in the impact of the next several sets of Pacific Northwest soundings. The evolution of the northern stream flow will have just as much impact on the future track of Irene as the evolution of the subtropical ridge, and the important shortwaves are just beginning to move into the North American RAOB network. It I had my way, I'd want an aircraft dropping sondes over the eastern pacific to get a better grasp on the northern stream flow.

Excellent post! Strongly agree. The differences we've seen in the various model runs today have had to do in large part with the intensity of the two troughs that will be swinging across the northern tier later this week

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It looked like Wilma did before it bombed at sunset. I mean, not exactly but you get the picture. ;)

But as I said elsewhere I'm sort of a RI weenie. /Please don't delete my post.

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While the impacts of the gulfstream dropsondes this afternoon are important, I'm actually more interested in the impact of the next several sets of Pacific Northwest soundings. The evolution of the northern stream flow will have just as much impact on the future track of Irene as the evolution of the subtropical ridge, and the important shortwaves are just beginning to move into the North American RAOB network. It I had my way, I'd want an aircraft dropping sondes over the eastern pacific to get a better grasp on the northern stream flow.

Totally agree, and part of the global model differences can be tied to the differences regarding the northern stream westerlies along the EC with the day 3-4 wave.

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While the impacts of the gulfstream dropsondes this afternoon are important, I'm actually more interested in the impact of the next several sets of Pacific Northwest soundings. The evolution of the northern stream flow will have just as much impact on the future track of Irene as the evolution of the subtropical ridge, and the important shortwaves are just beginning to move into the North American RAOB network. It I had my way, I'd want an aircraft dropping sondes over the eastern pacific to get a better grasp on the northern stream flow.

When will the PAC NW soundings be reflected in the models-- which runs?

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1st vortex, 981 mb, max FL winds 107 kts.

Storm Name: Irene (flight in the North Atlantic basin)

Mission Number: 7

Observation Number: 08

A. Time of Center Fix: 23rd day of the month at 0:49:00Z

B. Center Fix Coordinates: 19°49'N 68°51'W (19.8167N 68.85W)

B. Center Fix Location: 115 miles (185 km) to the NE (36°) from Santo Domingo, Dominican Republic.

C. Minimum Height at Standard Level: 2,944m (9,659ft) at 700mb

D. Estimated (by SFMR or visually) Maximum Surface Wind: 71kts (~ 81.7mph)

E. Location of the Estimated Maximum Surface Wind: 92 nautical miles (106 statute miles) to the W (269°) of center fix

F. Maximum Flight Level Wind Inbound: From 329° at 60kts (From the NNW at ~ 69.0mph)

G. Location of Maximum Flight Level Wind Inbound: 15 nautical miles (17 statute miles) to the WSW/W (259°) of center fix

H. Minimum Sea Level Pressure: 981mb (28.97 inHg)

I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 11°C (52°F) at a pressure alt. of 3,047m (9,997ft)

J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 17°C (63°F) at a pressure alt. of 3,050m (10,007ft)

K. Dewpoint Temp & Sea Surface Temp (collected at same location as temp inside eye): Not Available

L. Eye Character: Not Available

M. Eye Shape: Not Available

N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature

N. Fix Level: 700mb

O. Navigation Fix Accuracy: 0.02 nautical miles

O. Meteorological Accuracy: 3 nautical miles

Remarks Section:

Maximum Flight Level Wind: 107kts (~ 123.1mph) in the northwest quadrant at 23:30:20Z

Maximum Flight Level Temp: 17°C (63°F) which was observed 7 nautical miles to the W (266°) from the flight level center

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When will the PAC NW soundings be reflected in the models-- which runs?

0Z tonite will catch the leading portion of the jet streak. While it sounds unimportant, the overall strength of this jet streak will have major implications on amplification of the wave as it propagates eastward as well as the strength of the low level cold air advection...while will directly influence the upper level wind fields along the EC as well as the strength of the upper ridge.

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Excellent post! Strongly agree. The differences we've seen in the various model runs today have had to do in large part with the intensity of the two troughs that will be swinging across the northern tier later this week

TWC was just mentioning the same thing that you did. There is a small swirl over North Dakota that may not be included in the initialization of the models and also the upstream shortwave coming in to the Washington state coast that will probably have an effect of Irene in some way. I agree with you that some additional soundings would be a good idea to the northwest and out over the Pacific just off Seattle and Portland to sample that area.

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0Z tonite will catch the leading portion of the jet streak. While it sounds unimportant, the overall strength of this jet streak will have major implications on amplification of the wave as it propagates eastward as well as the strength of the low level cold air advection...while will directly influence the upper level wind fields along the EC as well as the strength of the upper ridge.

Cool-- and the 00Z runs will also reflect all of the G-IV data, if I understand correctly. So those runs should be interesting, to say the least!

P.S. It doesn't sound "unimportant" to me...

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When will the PAC NW soundings be reflected in the models-- which runs?

The Pac NW soundings are included in every 00z/12z run, since they are regularly scheduled releases. The key is the shortwaves that are key to pulling the system north are just now reaching the west coast after being in the data void pacific ocean. In the winter, you will often see significant changes in the modeling of east coast winter storms once the significant shortwaves move into the RAOB network. Who knows, maybe the models are handling the shortwaves well already, but if there are significant changes to happen, this is when they will be (during the next 24 hours of model runs).

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Wonder what happened to the eye, they didn't report anything about it this time through.

I. 11 C / 3047 m

J. 17 C / 3050 m

K. NA / NA

L. NA

M. NA

N. 12345 / 7

O. 0.02 / 3 nm

Could the flow over the DR be delaying the complete development of the eye wall? Looks like on satellite that a partial northern eyewall is there. The full outflow over the SW area is not complete yet. I believe when it moves away from Hispaniola it will complete itself and really deepen and intensify. Those 10K peaks could be holding it back some.

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Which are not perfectly separate issues, as a cyclone's intensity is expressed in terms of max winds, and those max winds are usually the result of core convection mixing the high-speed flow to the surface.

I'm not saying it's doing RI-- the whole conversation is silly-- but distinguishing between 1) a system's "representative" winds and 2) "localized, non-representative" winds is a big, messy topic.

Yep, it is.

I'm not saying intensification and convection aren't related - but there are instances where where a hurricane's winds might increase significantly because of stronger convection bringing stronger gusts closer to the surface, but the central pressure of the storm itself isn't really doing RI. That may be what's happening right now, but who knows-- we'll see in a few hours whether this is legit.

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The Pac NW soundings are included in every 00z/12z run, since they are regularly scheduled releases. The key is the shortwaves that are key to pulling the system north are just now reaching the west coast after being in the data void pacific ocean. In the winter, you will often see significant changes in the modeling of east coast winter storms once the significant shortwaves move into the RAOB network. Who knows, maybe the models are handling the shortwaves well already, but if there are significant changes to happen, this is when they will be (during the next 24 hours of model runs).

Thanks for explaining it. So the 00Z runs should begin to reflect some of this and perhaps give us hints? What are you expecting to happen-- rightward shifts or...?

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Thanks for explaining it. So the 00Z runs should begin to reflect some of this and perhaps give us hints? What are you expecting to happen-- rightward shifts or...?

If I had that kind of intuition, I'd be in a different line of work ;) In all seriousness, I have no idea what impact they will have.

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Thanks for explaining it. So the 00Z runs should begin to reflect some of this and perhaps give us hints? What are you expecting to happen-- rightward shifts or...?

I think these 00z runs should give us a good idea potentially because of the gulfstream data and the incoming jetstreak as ampsu said

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Updated vortex:

L. Eye Character: Closed Wall

M. Eye Shape & Diameter: Circular with a diameter of 30 nautical miles (35 statute miles)

and flight level winds of 107 kt

Josh, you would know about the new data ingest occurring at 0z/12z if you ever followed winter storms, but you dont :P

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