Hurricane Irene

[earthlight]

Use this thread to discuss the system including current presentation, short term forecasts, discussions, observations, and potential future impacts down the road. Do not use this thread to talk about comparisons to nor'easters, discuss exact details of a 168 hour model run at KJFK, or to say "this will be the best tropical system since...". Thanks.

[earthlight]

Looks like you can see, to some degree, the northern eyewall here on both infrared and water vapor satellites within the main area of convection.

Also, recon data has found 106 kft flight level winds in the north/northwest quadrant.

[nycsnow]

85kt surface wind to I believe

[earthlight]

Posted this in the old thread too, but I like the idea of a sharper recurve given the mid level ridge and active pattern over the northern half of the CONUS. The system is going to have to go inland over the Carolinas to get near our area. If that occurs it stands very little chance of being a hurricane when it reaches this latitude. It's also as much of a steering/mid level ridge issue as it is a active troughing pattern over the northern 1/3 of the conus.

[earthlight]

There it is. Category 2 now in a statement just issued.

000

WTNT64 KNHC 222348

TCUAT4

HURRICANE IRENE TROPICAL CYCLONE UPDATE

NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011

750 PM AST MON AUG 22 2011

...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

[bluewave]

My early guess will be to use a compromise of the GFS and Euro tracks at any given point in time.

Still too far out in time to guess the exact longitude when crossing around 40N, but the

GFS and Euro are currently not far apart at all for this far out in time.It will be interesting

to compare the Euro and GFS tracks as we get inside 120 hrs of crossing around 40N.

[billgwx]

Posted this in the old thread too, but I like the idea of a sharper recurve given the mid level ridge and active pattern over the northern half of the CONUS. The system is going to have to go inland over the Carolinas to get near our area. If that occurs it stands very little chance of being a hurricane when it reaches this latitude. It's also as much of a steering/mid level ridge issue as it is a active troughing pattern over the northern 1/3 of the conus.

I'd say be careful if you are using the GFS to come to that conclusion, as it is notorious for being too quick to erode Western Atlantic ridging ahead of an impending storm. GEFS ensemble members are often even worse in this regard. Am also awaiting NE Pacific disturbances which could affect the track to enter the N American raob network so they can perhaps be better sampled.

[NorEaster27]

Lets keep in mind astro high tides are this weknd with the new moon on Monday, even an offshore track can present coastal flood problems aside from the potential for heavy rain.

[billgwx]

My early guess will be to use a compromise of the GFS and Euro tracks at any given point in time.

For "better" or "worse" (in quotes because one person's better is likely to be another's worse when it comes to tropical cyclones!) I tend to agree with this.

[hudsonvalley21]

EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

240 PM EDT MON AUG 22 2011

VALID 12Z THU AUG 25 2011 - 12Z MON AUG 29 2011

...HURRICANE IRENE THREATENING THE EAST COAST LATE THIS WEEK/THIS

WEEKEND...

GLOBAL GUIDANCE WITHIN THE MAIN BAND OF THE WESTERLIES IS IN GOOD

AGREEMENT...WITH A PROGRESSIVE FLOW ANTICIPATED OVER THE NORTHERN

TIER OF THE COUNTRY AND A BREAK IN THE SUBTROPICAL RIDGE NEAR THE

SOUTHEAST COAST. THE GUIDANCE MOST SIMILAR TO THE MOST RECENT

NATIONAL HURRICANE CENTER /NHC/ FORECAST FOR HURRICANE IRENE WAS

THE 00Z CANADIAN. AS IT IS THE LARGEST SYSTEM ON THE MAP

PRESSURE-WISE...THIS LED TO A COMPROMISE OF THE 00Z CANADIAN/00Z

GEFS MEAN/00Z ECMWF ENSEMBLE MEAN FOR THE MORNING PRESSURES TO

MAINTAIN CONSISTENCY WITH NHC...WITH SOME INPUT FROM THE 00Z

ECMWF/06Z GFS ACROSS THE NORTHERN PLAINS WHERE THEY WERE SLIGHTLY

BETTER SUPPORTED BY THE ENSEMBLE MEAN SOLUTIONS. IRENES PLACEMENT

ON THE PROGS ACCELERATED 12 HOURS QUICKER PER THE 17Z COORDINATION

CALL WITH NHC TO ACCOUNT FOR ACCELERATION SEEN WITHIN THE 12Z RUN

OF THE GFS.

FOR IRENE AND THE EAST COAST...THE GUIDANCE HAS SHIFTED MORE TO

THE EAST WHICH COULD LEAD TO MORE TRENDING TO THE EAST/OFFSHORE IN

NHC FORECASTS LATER TODAY. ALTHOUGH INTERACTIONS WITH A COUPLE

SHORTWAVES MOVING THROUGH THE NORTHERN TIER OF THE COUNTRY

COMPLICATE THE FORECAST LATER IN THE MEDIUM RANGE PERIOD AS IRENE

PASSES NEAR NEW ENGLAND...IRENE SHOULD ROUND THE WESTERN PERIPHERY

OF THE SUBTROPICAL RIDGE ACROSS THE WESTERN SUBTROPICAL ATLANTIC

ALONG A PARABOLIC TRACK...WITH THE OUTER BANKS OF NORTH CAROLINA

AND CAPE COD MOST AT RISK AT THIS TIME. PER THE COORDINATED TRACK

WITH NHC AT 17Z...MODERATE TO HEAVY RAINS SHOULD INITIALLY FORM

ALONG A DEVELOPING COASTAL FRONT NEAR THE SOUTHEAST COAST WHICH

BECOMES REINFORCED BY A FRONT DROPPING IN FROM THE WESTERLIES.

HEAVY RAINS SHOULD SPREAD UP THE COAST OF THE MID-ATLANTIC AND NEW

ENGLAND STATES WITH TIME. THE CYCLONE IS THEN EXPECTED TO MOVE

ALONG THE COAST OF THE CAROLINAS OFFSHORE THE NORTHEAST JUST

INSIDE THE 40N/70W BENCHMARK SUNDAY. IF THE NHC TRACK SHIFTS

FARTHER TO THE RIGHT/EAST...THE THREAT FOR HEAVY RAINS ACROSS THE

SOUTHEAST/EAST COAST COULD LESSEN FURTHER. SEE THE LATEST

REASONING/TRACK FROM THE NHC REGARDING HURRICANE IRENE.

ROTH

[jm1220]

EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

240 PM EDT MON AUG 22 2011

VALID 12Z THU AUG 25 2011 - 12Z MON AUG 29 2011

...HURRICANE IRENE THREATENING THE EAST COAST LATE THIS WEEK/THIS

WEEKEND...

GLOBAL GUIDANCE WITHIN THE MAIN BAND OF THE WESTERLIES IS IN GOOD

AGREEMENT...WITH A PROGRESSIVE FLOW ANTICIPATED OVER THE NORTHERN

TIER OF THE COUNTRY AND A BREAK IN THE SUBTROPICAL RIDGE NEAR THE

SOUTHEAST COAST. THE GUIDANCE MOST SIMILAR TO THE MOST RECENT

NATIONAL HURRICANE CENTER /NHC/ FORECAST FOR HURRICANE IRENE WAS

THE 00Z CANADIAN. AS IT IS THE LARGEST SYSTEM ON THE MAP

PRESSURE-WISE...THIS LED TO A COMPROMISE OF THE 00Z CANADIAN/00Z

GEFS MEAN/00Z ECMWF ENSEMBLE MEAN FOR THE MORNING PRESSURES TO

MAINTAIN CONSISTENCY WITH NHC...WITH SOME INPUT FROM THE 00Z

ECMWF/06Z GFS ACROSS THE NORTHERN PLAINS WHERE THEY WERE SLIGHTLY

BETTER SUPPORTED BY THE ENSEMBLE MEAN SOLUTIONS. IRENES PLACEMENT

ON THE PROGS ACCELERATED 12 HOURS QUICKER PER THE 17Z COORDINATION

CALL WITH NHC TO ACCOUNT FOR ACCELERATION SEEN WITHIN THE 12Z RUN

OF THE GFS.

FOR IRENE AND THE EAST COAST...THE GUIDANCE HAS SHIFTED MORE TO

THE EAST WHICH COULD LEAD TO MORE TRENDING TO THE EAST/OFFSHORE IN

NHC FORECASTS LATER TODAY. ALTHOUGH INTERACTIONS WITH A COUPLE

SHORTWAVES MOVING THROUGH THE NORTHERN TIER OF THE COUNTRY

COMPLICATE THE FORECAST LATER IN THE MEDIUM RANGE PERIOD AS IRENE

PASSES NEAR NEW ENGLAND...IRENE SHOULD ROUND THE WESTERN PERIPHERY

OF THE SUBTROPICAL RIDGE ACROSS THE WESTERN SUBTROPICAL ATLANTIC

ALONG A PARABOLIC TRACK...WITH THE OUTER BANKS OF NORTH CAROLINA

AND CAPE COD MOST AT RISK AT THIS TIME. PER THE COORDINATED TRACK

WITH NHC AT 17Z...MODERATE TO HEAVY RAINS SHOULD INITIALLY FORM

ALONG A DEVELOPING COASTAL FRONT NEAR THE SOUTHEAST COAST WHICH

BECOMES REINFORCED BY A FRONT DROPPING IN FROM THE WESTERLIES.

HEAVY RAINS SHOULD SPREAD UP THE COAST OF THE MID-ATLANTIC AND NEW

ENGLAND STATES WITH TIME. THE CYCLONE IS THEN EXPECTED TO MOVE

ALONG THE COAST OF THE CAROLINAS OFFSHORE THE NORTHEAST JUST

INSIDE THE 40N/70W BENCHMARK SUNDAY. IF THE NHC TRACK SHIFTS

FARTHER TO THE RIGHT/EAST...THE THREAT FOR HEAVY RAINS ACROSS THE

SOUTHEAST/EAST COAST COULD LESSEN FURTHER. SEE THE LATEST

REASONING/TRACK FROM THE NHC REGARDING HURRICANE IRENE.

ROTH

Wow, they went east pretty far, just about hugging the 12z GFS with a coastal brush for the most part, and well east of NHC which slams it just about into Myrtle Beach. I'm not convinced it pulls an Earl, which initially was further NE than Irene is now and made a sharp recurve. It's hard for me to see it recurving like that, and its initially further west position makes it hard for me to believe we don't have some kind of direct impacts, especially near the coast. There could be a nice pre-storm rain event again due to the interaction with the trough and any associated front moving in. The 3rd trough would really have to dig in and progress east in a hurry. It certainly doesn't seem like a "worst case scenario" kind of a storm though, which is one moving due north or slightly NNE into western Long Island or NJ. For that to happen, the high would have to be further north and blocking an escape out to sea, or a trough would have to dig in fast and try a phase.

Even without a massive blow in this area though, just the rain and high 30-50 mph winds or so could result in a lot of downed trees due to the wet ground, more flooding damage, and beach erosion/coastal flooding from the astronomically occurring tides.

[A-L-E-X]

We could easily get our 20" of rain this month, even if the storm center went 100-150 miles to the east-- the western side is the rainier one, as prior experience has shown

Man, I've hearing everything from a scraper track, to a Bertha (1996) track to one over PA LOL

[A-L-E-X]

Posted this in the old thread too, but I like the idea of a sharper recurve given the mid level ridge and active pattern over the northern half of the CONUS. The system is going to have to go inland over the Carolinas to get near our area. If that occurs it stands very little chance of being a hurricane when it reaches this latitude. It's also as much of a steering/mid level ridge issue as it is a active troughing pattern over the northern 1/3 of the conus.

We would need a Bertha (1996) type of track, and I've seem some mets say that might happen.... basically a major near Wilmington, NC and then it tracked right over JFK as a 65 mph tropical storm and we had hurricane force gusts to around 80 mph..... still a very big deal for us. The heaviest rains were over the Poconos because of that track.

[patrick05]

excellent image from SSMI-S tonight... SW of the eyewall still open though

[Allsnow]

heres the 18z indiv ens tot qpf runs

Only one member is wide right for qpf.........

[A-L-E-X]

18z GEFS mean looks like a nice track for us.

http://icons-ecast.w...09_ensmodel.gif

That kind of coastal hugger track would probably be a low end Cat 1 right in my back yard.

[bkviking]

Just seems like that period of 1938 to 1960 is so difficult to repeat here on LI. Year after year since 1985s Gloria we see threats generate to only curve out to sea. Oddly enough, we are compensated for inhibited tropical strikes with a profundity of KU snowstorms. Regardless I am not stating I know Irene will bypass us; however, the day to day increment in right-curve is disconcerting to the tropical lover. Does a pattern in motion tend to stay in motion apply to 26 years of non-hurricane impacts here?

[billgwx]

18z GEFS mean looks like a nice track for us.

http://icons-ecast.w...09_ensmodel.gif

That kind of coastal hugger track would probably be a low end Cat 1 right in my back yard.

That's what I would think. TS Doria from 1971 is another pretty good analog. There is one worst case analog out there we really don't want to see.

[A-L-E-X]

That's what I would think. TS Doria from 1971 is another pretty good analog. There is one worst case analog out there we really don't want to see.

Yeah, it looks like a mish-mash of Doria/Belle/Bertha/Floyd on that plot lol. Just curious, which is the worst case analog you're thinking of? 1938?

[billgwx]

Yeah, it looks like a mish-mash of Doria/Belle/Bertha/Floyd on that plot lol. Just curious, which is the worst case analog you're thinking of? 1938?

I'll give one clue...it pre-dates the HURDAT database.

[donsutherland1]

I'll give one clue...it pre-dates the HURDAT database.

1821?

[billgwx]

1821?

You're too good at this game Don! We sure don't want to see anything like that, especially in NYC.

[NorEaster27]

1821?

me thinks so:

http://en.wikipedia.org/wiki/1821_Norfolk_and_Long_Island_hurricane

[SBUWX23]

1821?

wait, I thought hurricanes didnt happen back then

[donsutherland1]

We sure don't want to see anything like that, especially in NYC.

I completely agree, Bill.

[CT Rain]

One note about Doria... even though it was a 45knot TS when it crossed Long Island... it still produced the 6th greatest power outage in CT and W Mass on record. Given that the initial landfall in NC was a 60knot TS... I imagine this kind of track could produce more significant damage if the storm is as strong as some say it gets.

Though the pattern doesn't look ideal for a classic SNE/Long Island hurricane there is such a small sample size especially in the modern record that it's hard to rule out this kind of synoptic setup getting something up here.

1821 is an interesting (and scary) analog.

[A-L-E-X]

You're too good at this game Don! We sure don't want to see anything like that, especially in NYC.

I thought you might be thinking of 1893 LOL

BTW did we ever get some kind of consensus on how strong 1821 was up here? I know Josh is saying it couldn't have been stronger than a Cat 1 with the track it was on.

[A-L-E-X]

me thinks so:

http://en.wikipedia....sland_hurricane

How would a storm with that kind of track be a major up here though? And if it wasn't I wonder what caused that huge surge? Maybe it was that strong at one point and moving so rapidly that the surge stayed very high even though the storm weakened? And maybe it happened at high tide also.

[NorthNJwx]

One note about Doria... even though it was a 45knot TS when it crossed Long Island... it still produced the 6th greatest power outage in CT and W Mass on record. Given that the initial landfall in NC was a 60knot TS... I imagine this kind of track could produce more significant damage if the storm is as strong as some say it gets.

Though the pattern doesn't look ideal for a classic SNE/Long Island hurricane there is such a small sample size especially in the modern record that it's hard to rule out this kind of synoptic setup getting something up here.

1821 is an interesting (and scary) analog.

Interesting to hear that about Doria, which was way before my time. I could definitely see a 45-kt TS producing widespread tree damage along and E of the track in this part of the country, with the combination of fully-leafed, large trees and heavy rains to weaken the root systems. Floyd caused tree damage in my area, ~25 miles NNW of the city in a ~50-55-kt TS tracking over eastern LI. 14" of rain and gusts in the 40s can do that.

As for 1821: while it's an event I think most here would agree is way beyond something we'd want to "wish" for, I think it's just about the most fascinating weather event in the history of the Tri-State. It's the strongest hurricane (I have no idea if there's a consensus on its strength over NYC, but I'll say Cat 1-2 as a guess) to directly impact the heart of the city in recorded history. It must have been an unbelievable storm to watch.

[RutgersWx92]

How would a storm with that kind of track be a major up here though? And if it wasn't I wonder what caused that huge surge? Maybe it was that strong at one point and moving so rapidly that the surge stayed very high even though the storm weakened? And maybe it happened at high tide also.

This is wiki, so take it with a grain of salt, but this is what it says. Also note that this occurred at low tide apparently.

Modern researchers estimate it was a Category 3 or Category 4 hurricane upon striking New Jersey, one of the few hurricanes to hit the state.^[7][8] Moving ashore at very low tide,^[2] it paralleled the state's coastline just inland, and after exiting into Lower New York Bay the hurricane made landfall on New York City at around 1930 UTC on September 3; this makes it the only major hurricane to directly hit the city.^[1]