Major Hurricane Irene live tracking

[am19psu]

The new data is the fact that Irene is likely undergoing rapid intensification, requiring them to increase the intensity forecast. They are NOT releasing a new track/cone that is any different from the one on the 21Z suite

I've been wrong about RI before, but I doubt it is undergoing RI with an open eyewall to the south.

[Ian]

Please also note a model thread on Irene:

[jburns]

Category 2 intensity with the eye still not discernible on satellite yet.

Strengthening rather rapidly while still being affected by the close proximity to Hispaniola. Looks like conditions trumped a glancing blow from the island for once. From here it should be off to the races.

[OSUmetstud]

I've been wrong about RI before, but I doubt it is undergoing RI with an open eyewall to the south.

If we use the 30 kt threshold...it's there.

[dan88]

Recon decided to do the next pass at 700mb, rather than at 850mb as they did with the previous pass.

[Typhoon Tip]

I've been wrong about RI before, but I doubt it is undergoing RI with an open eyewall to the south.

Agreed ...when I read that I wasn't blown away either. It could intensify at a slower rate and still be dangerous anyway but...

[am19psu]

If we use the 30 kt threshold...it's there.

Well, true, but going from 55 to 85 is a lot different than 70 to 100 with an open eyewall.

[wxsmwhrms]

Recon decided to do the next pass at 700mb, rather than at 850mb as they did with the previous pass.

Probably a wise safety decision given the strength and intensification. They don't like flying that low given the situation.

[HurricaneJosh]

I hope it isn't doing RI. We all know what happens when they spin up really, really fast five days before landfall. The idea gives me no pleasure.

[OSUmetstud]

Well, true, but going from 55 to 85 is a lot different than 70 to 100 with an open eyewall.

for sure...I think the 30 kt threshold is decent for weaker storms since the rate of intensification is governed by how strong the low is initially.

[OKpowdah]

They are issuing a full package due to the increase in category. I doubt they will make any significant changes to track - but it will be a complete update with all products.

...IRENE NOW A CATEGORY TWO HURRICANE... REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE THAT IRENE HAS STRENGTHENED...AND IS NOW A CATEGORY TWO HURRICANE WITH MAXIMUM SUSTAINED WINDS OF 100 MPH...155 KM/H. DETAILS WILL FOLLOW IN A SPECIAL ADVISORY TO BE ISSUED BY 815 PM AST...0015 UTC. SUMMARY OF 750 PM AST...2350 UTC...INFORMATION -------------------------------------------------- LOCATION...19.7N 68.7W ABOUT 200 MI...320 KM SE OF GRAND TURK ISLAND ABOUT 130 MI...210 KM E OF PUERTO PLATA DOMINICAN REPUBLIC MAXIMUM SUSTAINED WINDS...100 MPH...155 KM/H PRESENT MOVEMENT...WNW OR 295 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...981 MB...28.97 INCHES $ FORECASTER BRENNAN

Just because they're calling it a special advisory doesn't mean they're updating the full package. They don't update the track for intermediate advisories. I've never seen them update the track for any RI cases. I think it's just intensity.

[OSUmetstud]

I hope it isn't doing RI. We all know what happens when they spin up really, really fast five days before landfall. The idea gives me no pleasure.

come on now...it's a 24-30 nm eye Cat 2. ERC isn't even in the picture yet.

[OKpowdah]

The new data is the fact that Irene is likely undergoing rapid intensification, requiring them to increase the intensity forecast.

Irene is not undergoing RI. Recon just got in there, and found higher winds than they did this morning ... it's been steady intensification. Also, mainly look at min pressure for determining RI

[HurricaneJosh]

come on now...it's a 24-30 nm eye Cat 2. ERC isn't even in the picture yet.

Right. And I don't want to see RI now-- the cyclone will peak early and 5 ERCs later, it'll be just be mushy crap as it comes ashore.

[dan88]

New forecast has major at 24 hours, peak at 110kts shortly after

[HurricaneJosh]

New forecast has major at 24 hours, peak at 110kts shortly after

That's a big increase for the NHC, which tends to be conservative with changes.

[am19psu]

New forecast has major at 24 hours, peak at 110kts shortly after

FORECAST VALID 23/0600Z 20.1N  70.2W
MAX WIND  95 KT...GUSTS 115 KT.
64 KT... 40NE  10SE  10SW  30NW.
50 KT... 60NE  30SE  20SW  60NW.
34 KT...160NE  75SE  45SW 110NW.

FORECAST VALID 23/1800Z 20.8N  72.5W
MAX WIND 105 KT...GUSTS 130 KT.
64 KT... 45NE  15SE  15SW  35NW.
50 KT... 70NE  40SE  30SW  60NW.
34 KT...160NE  75SE  55SW 120NW.

FORECAST VALID 24/0600Z 21.5N  74.0W
MAX WIND 110 KT...GUSTS 135 KT.
64 KT... 45NE  15SE  15SW  35NW.
50 KT... 70NE  40SE  30SW  60NW.
34 KT...160NE  75SE  55SW 130NW.

FORECAST VALID 24/1800Z 23.0N  75.5W
MAX WIND 110 KT...GUSTS 135 KT.
50 KT... 80NE  50SE  40SW  70NW.
34 KT...160NE  75SE  55SW 130NW.

FORECAST VALID 25/1800Z 26.0N  78.0W
MAX WIND 110 KT...GUSTS 135 KT.
50 KT... 90NE  60SE  40SW  70NW.
34 KT...160NE  90SE  60SW 140NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 175 NM
ON DAY 4 AND 225 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 26/1800Z 29.5N  79.0W
MAX WIND 105 KT...GUSTS 130 KT.

OUTLOOK VALID 27/1800Z 34.0N  79.0W...INLAND
MAX WIND  95 KT...GUSTS 115 KT.

Makes sense to me. If anything, I might go stronger Wednesday into Thursday when conditions are really ripe. Really depends when the eyewall forms completely and how long until the first ERC.

[OSUmetstud]

Right. And I don't want to see RI now-- the cyclone will peak early and 5 ERCs later, it'll be just be mushy crap as it comes ashore.

I think almost every major goes under RI at some point. You'll get your RI and deal with it.

[phil882]

I'm in Adam's camp too, I doubt RI is underway... The pressure really didn't drop that much from the last recon pass. I was pretty surprised to see the winds that high.

[wxsmwhrms]

Just because they're calling it a special advisory doesn't mean they're updating the full package. They don't update the track for intermediate advisories. I've never seen them update the track for any RI cases. I think it's just intensity.

Look, I work for the NWS at a tropical office, and I know what NHC is doing. A special advisory means that they are issuing an entire new set of products. Now, you are right that they will probably not change the track, but that's a choice, not an "automatic." By saying what you're saying, you're making it out like TWC is wrong. They're not. It is a new forecast, and if the forecaster wanted to change the track, he could. If this was a situation where landfall was more imminent and there was a reason for a change, they would update the track as well. That is the point.

[OKpowdah]

Look, I work for the NWS at a tropical office, and I know what NHC is doing. A special advisory means that they are issuing an entire new set of products. Now, you are right that they will probably not change the track, but that's a choice, not an "automatic." By saying what you're saying, you're making it out like TWC is wrong. They're not. It is a new forecast, and if the forecaster wanted to change the track, he could. If this was a situation where landfall was more imminent and there was a reason for a change, they would update the track as well. That is the point.

Oh well if TWC says it, then I'll bow before them of course

Anyway, they didn't update the track forecast.

[HurricaneJosh]

Look, I work for the NWS at a tropical office, and I know what NHC is doing. A special advisory means that they are issuing an entire new set of products. Now, you are right that they will probably not change the track, but that's a choice, not an "automatic." By saying what you're saying, you're making it out like TWC is wrong. They're not. It is a new forecast, and if the forecaster wanted to change the track, he could. If this was a situation where landfall was more imminent and there was a reason for a change, they would update the track as well. That is the point.

It's great to have clarification from a knowledgeable source like this-- thank you. Now we can put this issue-- and misconceptions-- to rest.

[Floydbuster]

Does anyone know where I can find the Dorvak graph, which shows the wind and pressure? Or, would someone post it for me?

Do the meteorologists here have any sort of feelings towards the Dorvak-- find it accurate at all?

http://www.ssd.noaa.gov/PS/TROP/CI-chart.html

[dan88]

Quite the nice burst of convection this evening

During the past hour or so the burst in convection which was focused to the north has really wrapped down over the center quite well.

[Solak]

830 PM AST MON AUG 22 2011 THE HURRICANE HUNTER AIRCRAFT FOUND A 850-MB FLIGHT LEVEL WIND MAXIMUM OF 106 KT ON ITS FIRST PASS THROUGH THE CENTER OF IRENE. BASED ON THIS...THE INITIAL INTENSITY IS ADJUSTED UPWARD TO 85 KT. OVER THE PAST COUPLE OF HOURS THE SATELLITE PRESENTATION OF THE HURRICANE HAS CONTINUED TO IMPROVE...ALTHOUGH NO EYE IS VISIBLE YET IN GEOSTATIONARY IMAGERY. HOWEVER...AN EYE HAS BECOME APPARENT ON THE SAN JUAN DOPPLER RADAR AND WAS ALSO SEEN IN A 2230 UTC SSMIS PASS. THE CENTRAL PRESSURE HAS FALLEN TO 981 MB BASED ON A DROPSONDE OBSERVATION OF 982 MB WITH 10 KT OF WIND AT THE SURFACE. GIVEN THAT THE ENVIRONMENT APPEARS CONDUCIVE FOR ADDITIONAL STRENGTHENING...THE INTENSITY FORECAST HAS BEEN ADJUSTED UPWARD BY 15 KT THROUGH 36 HOURS WITH A SMALLER UPWARD ADJUSTMENT AT 48 AND 72 HOURS. ONLY SLIGHT WEAKENING IS INDICATED AT DAYS 4 AND 5. THE NEW FORECAST NOW SHOWS IRENE BECOMING A MAJOR HURRICANE ON TUESDAY AS IT MOVES THROUGH THE SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS. THE WIND RADII HAVE BEEN EXPANDED BASED ON AIRCRAFT DATA AND THE NEW INTENSITY FORECAST. NO CHANGES HAVE BEEN MADE TO THE TRACK FORECAST ON THIS SPECIAL ADVISORY.

[am19psu]

Does anyone know where I can find the Dorvak graph, which shows the wind and pressure? Or, would someone post it for me?

Do the meteorologists here have any sort of feelings towards the Dorvak-- find it accurate at all?

Not sure what you are asking for in your first question... do you mean just what T4.5 relates to for pressure and wind? You can find that here.

Dvorak was the best way to estimate hurricane/typhoon/tropical cyclone wind speeds before the advent of microwave imagery. I suspect within the next 5 years, we'll have superior techniques to estimate intensity utilizing more modern technology (e.g. CIMSS SATCON)

[dan88]

Looks like we are getting a 700mb due West to East pass this time around as recon approaches the center along 19.8N.

[WishingForWarmWeather]

Not sure what you are asking for in your first question... do you mean just what T4.5 relates to for pressure and wind? You can find that here.

Dvorak was the best way to estimate hurricane/typhoon/tropical cyclone wind speeds before the advent of microwave imagery. I suspect within the next 5 years, we'll have superior techniques to estimate intensity utilizing more modern technology (e.g. CIMSS SATCON)

I just wanted to know where I could find it-- for some reason when I googled it wouldn't give me anything.

And after that, I was just curious if anyone else thought it was an important tool to use. I always look at the Dorvak numbers. Obviously not as a bible or anything, but I think it is always pretty relative to the actual numbers, and sometimes seems to sense things that my naked eye cannot see.

I also agree, about having much more superior techniques. Perhaps even earlier than 5 years.

I often wonder why the very knowledgeable group of meterologists on this site do not all have a giant meeting and 1) put together their own hurricane model-- everyone always has criticisms here on the current ones, and I just think with the amount of intelligence on this thread that an elite model could be developed and 2) develop a way to improve upon the cimss satcon/dorvak/etc techniques of estimating intensity. There is so just so much talent on this board that I just think many things could be accomplished with everyone in one room. Or maybe they'd just argue the whole time-- ya know, whatever.

[Kmlwx]

I just wanted to know where I could find it-- for some reason when I googled it wouldn't give me anything.

And after that, I was just curious if anyone else thought it was an important tool to use. I always look at the Dorvak numbers. Obviously not as a bible or anything, but I think it is always pretty relative to the actual numbers, and sometimes seems to sense things that my naked eye cannot see.

I also agree, about having much more superior techniques. Perhaps even earlier than 5 years.

I often wonder why the very knowledgeable group of meterologists on this site do not all have a giant meeting and 1) put together their own hurricane model-- everyone always has criticisms here on the current ones, and I just think with the amount of intelligence on this thread that an elite model could be developed and 2) develop a way to improve upon the cimss satcon/dorvak/etc techniques of estimating intensity. There is so just so much talent on this board that I just think many things could be accomplished with everyone in one room. Or maybe they'd just argue the whole time-- ya know, whatever.

You were probably searching for "Dorvak" when it is Dvorak. Might have gotten you some better results

Slightly OT but it is not always as simple as having a conference and developing a model. There is way more than that in developing new techniques and technologies. Not all of the mets on this forum are well versed in the computer technology (some are, though) that is required for this.

[thewxmann]

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.