Major Hurricane Katia

[Cookie]

Beautiful storm

[Paranoid]

Katia will probably also provide a significant boost to the ACE values so far. Irene's responsible for most of the energy accumulated, so Katia could quite easily double the current value by the time she dissipates (barring any unexpected obstacles).

[lfcdude]

http://www.stormpulse.com/

wow should be cat 4 by Sunday.. wonder how obama and co would talk about this if it hits usa.... biggest storm of the century? public? was that not just over a week ago?

On the forecast module.. what one do you think will be the most accurate? as i will be keeping an eye on this over the coming week.

[Iceberg]

Models are still in sandpit playing mode with Katia IMO.

They all failed to get the speed right, as she has been ploughing forward much faster than the models indicated a 2 days ago. This extra speed then almost definately means she hits an initial weakness in the ridge earlier. However this ridge is something of a dead end and she will then be steered west or be calmed.

After this time the latest favourite model(sand castle) is for a couple of extra tropical storms/hurricanes to develop one in the GOM which reinforces the Ridge above it and one near N.Carolina which for might help to weaken the ridge allowing Katia to move northwards quicker or it might collide with Katia which is what ECM shows.

All in All the models still have no realistic way of finishing the re-curve and entry through the first dead end weakness.

In apperance Katia is not that impressive for me, it has some good outflow, but is still not at Hurricane strength yet, whether it reaches CAT 4 or even 5 with as always be down to internal dynamics, something I am not sure about yet as we havent really seen the centre do what it can do.

The shot for Katia to strengthen is quite limited, as soon as it's forward speed slows down to a crawl it will rapidly use up the OHC and intensification will be difficult, from there on the SST's will not support a CAT 5 or high end CAT 4.

Edited August 31, 2011 by Iceberg

[Coast]

She just doesn't seem to make the really big ratings:

[Soaring Hawk]

BULLETIN

TROPICAL STORM KATIA ADVISORY NUMBER 9

NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011

500 AM AST WED AUG 31 2011

...KATIA GRADUALLY STRENGTHENING AS IT MOVES QUICKLY

WEST-NORTHWESTWARD...

SUMMARY OF 500 AM AST...0900 UTC...INFORMATION

----------------------------------------------

LOCATION...13.9N 39.1W

ABOUT 985 MI...1585 KM W OF THE SOUTHERNMOST CAPE VERDE ISLANDS

MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H

PRESENT MOVEMENT...WNW OR 285 DEGREES AT 21 MPH...33 KM/H

MINIMUM CENTRAL PRESSURE...994 MB...29.35 INCHES

WATCHES AND WARNINGS

--------------------

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

DISCUSSION AND 48-HOUR OUTLOOK

------------------------------

AT 500 AM AST...0900 UTC...THE CENTER OF TROPICAL STORM KATIA WAS

LOCATED NEAR LATITUDE 13.9 NORTH...LONGITUDE 39.1 WEST. KATIA IS

MOVING TOWARD THE WEST-NORTHWEST NEAR 21 MPH...33 KM/H...AND THIS

GENERAL MOTION IS EXPECTED TO CONTINUE WITH A GRADUAL DECREASE IN

FORWARD SPEED DURING THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 65 MPH...100 KM/H...

WITH HIGHER GUSTS. ADDITIONAL STRENGTHENING IS FORECAST DURING THE

NEXT 48 HOURS...AND KATIA COULD BECOME A HURRICANE LATER TODAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 85 MILES...140 KM

FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB...29.35 INCHES.

HAZARDS AFFECTING LAND

----------------------

NONE.

NEXT ADVISORY

-------------

NEXT COMPLETE ADVISORY...1100 AM AST.

$$

FORECASTER BEVEN

Interesting wait during the day to see if she makes hurricane status.

Edited August 31, 2011 by Soaring Hawk

[ChartViewer]

000

WTNT42 KNHC 310837

TCDAT2

TROPICAL STORM KATIA DISCUSSION NUMBER 9

NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011

500 AM AST WED AUG 31 2011

SATELLITE IMAGERY THIS MORNING INDICATES THAT KATIA IS GRADUALLY

BECOMING BETTER ORGANIZED. THE PRIMARY CONVECTIVE BAND HAS WRAPPED

FARTHER AROUND THE CENTER...AND THE CLOUD TOPS IN THE BAND HAVE

COOLED. SATELLITE INTENSITY ESTIMATES ARE 55 KT FROM SAB AND

TAFB...AND THAT IS THE INITIAL INTENSITY FOR THIS ADVISORY. THE

CIRRUS OUTFLOW IS FAIR TO GOOD IN ALL DIRECTIONS.

THE INITIAL MOTION IS 285/18. KATIA IS ON THE SOUTH SIDE OF A

DEEP-LAYER SUBTROPICAL RIDGE...WHILE WATER VAPOR IMAGERY SHOWS A

LARGE MID/UPPER-LEVEL LOW...A WEAKNESS IN THE RIDGE...CENTERED NEAR

30N54W AND MOVING WESTWARD. THE TRACK GUIDANCE IS IN VERY GOOD

AGREEMENT THAT KATIA SHOULD MOVE GENERALLY WEST-NORTHWARD FOR THE

NEXT 48 HR OR SO....THEN GRADUALLY TURN TOWARD THE NORTHWEST AT A

SLOWER FORWARD SPEED AS IT APPROACHES THE LOW OR ITS REMNANTS. THE

GUIDANCE ENVELOPE HAS SHIFTED A LITTLE TO THE SOUTH DURING THE

FIRST 36 HR...AND SHIFTED A LITTLE TO THE NORTH AFTER THAT TIME.

THE NEW FORECAST TRACK MAKES SIMILAR SMALL ADJUSTMENTS COMPARED TO

THE PREVIOUS FORECAST AND LIES NEAR THE VARIOUS CONSENSUS MODELS.

A COUPLE OF ISSUES HAVE APPEARED REGARDING THE INTENSITY FORECAST.

FIRST...WATER VAPOR IMAGERY AND MICROWAVE TOTAL PRECIPITABLE WATER

DATA SHOW DRY AIR NOT FAR TO THE NORTH AND EAST OF THE CORE OF

KATIA. THIS HAS NOT YET AFFECTED DEVELOPMENT...AND THE NEW

INTENSITY FORECAST KEEPS THE TREND OF THE PREVIOUS FORECAST FOR THE

FIRST 36 HR. HOWEVER...THERE IS A POSSIBILITY THAT INTENSIFICATION

COULD BE SLOWER THAN FORECAST IF THE DRY AIR REACHES THE CENTER.

SECOND...THE DYNAMICAL MODELS DISAGREE ON THE UPPER-LEVEL WINDS

NEAR KATIA FROM 72-120 HR. THE GFS...NOGAPS... AND CANADIAN MODELS

SHOW THE UPPER-LEVEL LOW TO THE NORTHWEST WEAKENING TO THE POINT

WHERE THE STORM REMAINS IN LIGHT VERTICAL WIND SHEAR CONDITIONS.

THE ECMWF AND UKMET KEEP A STRONG ENOUGH UPPER-LEVEL TROUGH FOR

KATIA TO EXPERIENCE SIGNIFICANT SOUTHWESTERLY SHEAR. THE FORECAST

INTENSITIES HAVE BEEN LOWERED SLIGHTLY AFTER 48 HR DUE TO THE

POSSIBILITY OF SHEAR DURING THAT TIME.

FORECAST POSITIONS AND MAX WINDS

INIT 31/0900Z 13.9N 39.1W 55 KT 65 MPH

12H 31/1800Z 14.3N 41.7W 65 KT 75 MPH

24H 01/0600Z 15.0N 44.9W 75 KT 85 MPH

36H 01/1800Z 15.8N 47.7W 85 KT 100 MPH

48H 02/0600Z 16.8N 50.2W 90 KT 105 MPH

72H 03/0600Z 19.0N 54.0W 95 KT 110 MPH

96H 04/0600Z 21.0N 57.0W 100 KT 115 MPH

120H 05/0600Z 23.0N 60.0W 105 KT 120 MPH

$$

FORECASTER BEVEN

Edited August 31, 2011 by ChartViewer

[onlyME]

My opinion is this has a real shot a cat 5 status. I truly hope it goes out to sea!

I don't think so because I think(not 100 % sure) in satellite era there weren't any Category 5 fish storms and some models think that ULL or something else centered on 30 N and 52-53 W won't move and will produce significant southwesterly wind shear on Katia.

[mezzacyclone]

NHC moved the 5 day Conus roughly 100 mile NE as previous edge was right on St Martin & Barbuda shoreline?

[summer blizzard]

Some of you are being far too bullish.

Kalia is already gaining lattitude on a WNW and has infact sped up (suprised the core is holding actually). While shear should be fairly low until Katia slows and this is likely to put her further west than expected, it is very unlikely that she will be stronger than a weak category 4 given that she is in the open sea. In terms of eventual track there are a few models forecasting a hit on Nova Scotia which is possible although i suspect she will stay out to sea.

In summary, a pretty strong FISH. Not a threat to anybody except isolated islands.

[AderynCoch]

Katia's forecast track has moved northwards over the past 24 hours, making an impact on the Caribbean increasingly unlikely. Could well hit Bermuda though.

Category 5 is also a big stretch, but I don't see why Katia couldn't spend a while at Category 3 or 4 like Igor did.

[Iceberg]

Katia's track fate is very much in the hands of Invest 93L. The models by and large don't interact 93L and the hurricane it forms, into the trough that drags Katia at rocket speed NE back into the atlantic. Due to this the 12Z models such as the ECM drag Katia much further west on this run, ECM even has a SW movement into the Bahamas out in FI before another trough picks it up and weakens the ridge.

So IMO we are really no closer to figuring out what Katia does when she slows down.

Moving on to her current structure I am not very impressed to be honest, banding and outflow are excellent, but dry air is getting mixed in and she is not at Hurricane strength IMO. Still I am sure she will be soon.

[Iceberg]

Now finally it's Hurricane Katia.

convection is looking more solid now, but some evidence still on dry air. The models are still a mess beyond T144, this is the ECM that introduces yet another tropical storm/hurricane with a a fujiwara effect on Katia (as well as 93L in the GOM). This has the effect of weakening the ridge, strengthening the Jet and in part slowing Katia down. However there is no doubt that ECM is showing far too much energy up into the trough and I doubt that such a storm would exist and form so near to Katia and so quickly.

Essentially a lot of energy is out between the GOM and the NE coast and the models are having difficulty in guaging it's strengthen and direction with a new solution every run.

Edited September 1, 2011 by Iceberg

[Coast]

Still a lot of divergence between the models as to where Katia will go:

[Harry]

Now finally it's Hurricane Katia.

convection is looking more solid now, but some evidence still on dry air. The models are still a mess beyond T144, this is the ECM that introduces yet another tropical storm/hurricane with a a fujiwara effect on Katia (as well as 93L in the GOM). This has the effect of weakening the ridge, strengthening the Jet and in part slowing Katia down. However there is no doubt that ECM is showing far too much energy up into the trough and I doubt that such a storm would exist and form so near to Katia and so quickly.

Essentially a lot of energy is out between the GOM and the NE coast and the models are having difficulty in guaging it's strengthen and direction with a new solution every run.

Who is the little chap in the Gulf of Mexico?

Is that one of the forecast tracks for Katia?

[Paul Sherman]

Changing Thread Title for you guys

[Cookie]

Changing Thread Title for you guys

thanks

[ChartViewer]

000

WTNT42 KNHC 010837

TCDAT2

HURRICANE KATIA DISCUSSION NUMBER 13

NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011

500 AM AST THU SEP 01 2011

AN AMSR-E OVERPASS AT 0451 UTC RATHER UNEXPECTEDLY SHOWED A PARTLY

EXPOSED LOW-LEVEL CENTER WITH ONLY A FRAGMENT OF AN EYEWALL TO THE

NORTH AND NORTHEAST. ANALYSES FROM CIMSS AT THE UNIVERSITY OF

WISCONSIN SHOW ABOUT 10 KT OF SOUTHERLY VERTICAL WIND SHEAR...BUT

THAT BY ITSELF DOES NOT ADEQUATELY EXPLAIN THE OBSERVED STRUCTURE.

IT MAY BE THAT DRY AIR PREVIOUSLY SEEN NEAR THE STORM HAS WORKED ITS

WAY INTO THE CORE AS HINTED AT IN AMSR-E TOTAL PRECIPITABLE WATER

DATA. SATELLITE INTENSITY ESTIMATES ARE 77 KT FROM TAFB AND 65 KT

FROM SAB...AND THE INITIAL INTENSITY REMAINS 65 KT FOR THIS

ADVISORY.

THE INITIAL MOTION IS SLIGHTLY TO THE LEFT OF THE PREVIOUS

ADVISORY...280/17. KATIA IS ON THE SOUTH SIDE OF A DEEP-LAYER

RIDGE OVER THE CENTRAL ATLANTIC. WATER VAPOR IMAGERY SHOWS A

MID/UPPER-LEVEL LOW NEAR 29N55W WITH A TROUGH EXTENDING TO 15N60W...

AND A SECOND MID/UPPER-LEVEL LOW NEAR 34N71W. THESE FEATURES HAVE

CREATED A SIZABLE WEAKNESS IN THE SUBTROPICAL RIDGE OVER THE

WESTERN ATLANTIC...AND THE DYNAMICAL MODELS FORECAST KATIA TO MOVE

GENERALLY WEST-NORTHWESTWARD INTO THE WEAKNESS. THERE IS SOME

SPREAD IN THE GUIDANCE...ESPECIALLY BY 120 HOURS. THE GFDL...

UKMET...CANADIAN...AND NOGAPS MODELS ARE ON THE LEFT SIDE OF THE

GUIDANCE ENVELOPE...WHILE THE GFS AND ECMWF ARE ON THE RIGHT SIDE.

THE NEW FORECAST TRACK IS ALONG THE LEFT SIDE OF THE GUIDANCE

ENVELOPE FOR THE FIRST 24 HOURS BASED ON THE CURRENT MOTION...THEN

THEREAFTER LIES IN THE CENTER OF THE ENVELOPE NEAR THE VARIOUS

CONSENSUS MODELS. THE NEW TRACK IS A LITTLE TO THE WEST OF THE

PREVIOUS TRACK.

IT IS UNCLEAR WHETHER THE CURRENT CONVECTIVE TREND IS TEMPORARY OR A

SIGN OF ARRESTED DEVELOPMENT. THE EARLY PART OF THE INTENSITY

FORECAST IS BASED ON THE FORMER POSSIBILITY AND SHOWS A SLOW

STRENGTHENING FOR THE FIRST 24-36 HR. AFTER THAT TIME...THERE

REMAINS SOME UNCERTAINTY REGARDING THE UPPER-LEVEL WINDS NEAR

KATIA. THE GFS...NOGAPS...AND CANADIAN MODELS SHOW A VERY

FAVORABLE PATTERN...WHILE THE UKMET AND ECMWF FORECAST SOME

SOUTHWESTERLY SHEAR. DUE TO THE UNCERTAINTY...THE LATER PART OF

THE INTENSITY FORECAST IS THE SAME AS IN THE PREVIOUS ADVISORY.

HOWEVER...THE GFDL AND GFDN MODELS BOTH FORECAST KATIA TO INTENSIFY

TO STRONGER THAN 120 KT...WHICH IS A POSSIBILITY IF THE MORE

FAVORABLE UPPER-LEVEL WINDS OCCUR.

FORECAST POSITIONS AND MAX WINDS

INIT 01/0900Z 15.2N 45.9W 65 KT 75 MPH

12H 01/1800Z 15.7N 48.1W 70 KT 80 MPH

24H 02/0600Z 16.5N 50.5W 80 KT 90 MPH

36H 02/1800Z 17.6N 52.4W 90 KT 105 MPH

48H 03/0600Z 18.6N 54.1W 95 KT 110 MPH

72H 04/0600Z 20.5N 57.0W 100 KT 115 MPH

96H 05/0600Z 22.0N 60.0W 105 KT 120 MPH

120H 06/0600Z 23.5N 63.0W 105 KT 120 MPH

$$

FORECASTER BEVEN

[yamkin]

Katia from the International Space Station - August 31, 2011

http://www.youtube.com/watch?v=7Eoa19pRHiQ&feature=uploademail

[Paranoid]

Just noticed that the latest GFDL run brings Katia up to 135kt at T-84, which would put it just into Cat 5 status. While at the moment i'm a bit more skeptical about Katia's chances of reaching Cat 5, this latest run seems to be part of a trend which has been slowly increasing Katia's peak intensity. As such, i don't think Katia reaching the moderate - upper end of Cat 4 should be ruled out. This depends really on how Katia deals with the dry air and moderate shear in it's current environment.

Edited September 1, 2011 by Paranoid

[Iceberg]

Katia looks to be suffering tonight and is only just hanging on to Hurricane status IMO, the main culprit is SW shear, The centre is just in the main CDO.

I still have my doubts that Katia will be anything higher than a CAT 3 and maybe not even a CAT 3 unless a better environment shows itself.

The track is still not decided, this is the ECM at 180 ? (I think) that places Katia out west, it then manages to engage the trough and so gets sweeped NE, However the models have been weakening these troughs, strengthening the ridges and moving Katia further and further west before getting picked up, this is now pretty much last chance saloon for the non US hit re-curve. Any more west at day 5-6 and the re-curve will hit similar places to Irene.

[Iceberg]

Another significant shift west on the models as the models fail again put the energy into the trough, This now allows GFS to get in touching distance of a US Hit very similar to Irene.ECM is equally is not quite as far west but still very close to the Coast.

Despite the models direction, Katia looks to have another 5-8 days as a hurricane so plenty of time for conditions to get variably better and worse.

Looking at her atm, she is probably a hurricane, the CDO has expanded as the shear looks to have lessened.

[knocker]

An assessment of the formation of Katia from NASA with some interesting images.

http://www.nasa.gov/mission_pages/hurricanes/archives/2011/h2011_Katia.html

[Coast]

Another significant shift west on the models as the models fail again put the energy into the trough, This now allows GFS to get in touching distance of a US Hit very similar to Irene.ECM is equally is not quite as far west but still very close to the Coast.

Oil production being shut down in anticipation:

Tropical Depression Katia Stalls South of Louisiana, Likely to Strengthen

A tropical depression in the Gulf of Mexico that has shut almost 6 percent of the region’s oil production stalled south of Louisiana, according to the National Hurricane Center. The system is “nearly stationary” about 240 miles (385 kilometers) southwest of the Mississippi River mouth, the Miami- based center said in an advisory issued before 2 a.m. East Coast time today. The depression could become a tropical storm later today before reaching Louisiana over the weekend. “A slow northwestward drift is expected to start later today followed by a turn to the north tonight or Saturday,” the center said. “Gradual strengthening is forecast during the next 48 hours.”

Companies including Anadarko Petroleum Corp., BP Plc, Exxon Mobil Corp. and Noble Corp have evacuated workers from Gulf rigs and platforms. About 5.7 percent of Gulf oil production and 2.4 percent of natural gas output has been shut by the storm, according to the Bureau of Ocean Energy Management, Regulation and Enforcement. The Gulf accounts for 27 percent of U.S. oil output and 6.5 percent of natural gas production.

“There’s nothing really to move this system out of the Gulf,” Jill Hasling, president of the Weather Research Center in Houston, said in a telephone interview. “It looks like this thing is just going to sit there, with storm-force winds blowing, for days.”

State of Emergency

Louisiana Governor Bobby Jindal declared a state of emergency, saying the storm threatens to pour “extremely heavy, prolonged” rain over the state and cause flash flooding and high tides. Ten to 15 inches (25 to 38 centimeters) of rain is expected to fall over southern Louisiana, Mississippi and Alabama through Sept. 4, according to the hurricane center. As much as 20 inches may accumulate in some isolated areas, the center said. The National Weather Service issued a tropical storm warning for the coast of the northern Gulf of Mexico, from Pascagoula, Mississippi, to Sabine Pass, Texas.

The system has a 30 percent chance of becoming a Category 3 major hurricane that would disrupt oil and gas output, according to Meteorologist Matt Rogers at Commodity Weather Group in Bethesda, Maryland. An estimated 15 percent of natural gas production and 5.4 percent of oil production in the Gulf may be shut for the next five to 30 days, according to Kinetic Analysis Corp., a Silver Spring, Maryland-based company that predicts the effects of disasters.

Platform Evacuations

BP said it will remove all workers from Gulf platforms by today. The London-based company on Sept. 1 began moving more than 500 non-essential workers from some platforms in the Southern Green Canyon area, according to a message on the company’s hurricane hot line. Diamond Offshore Drilling Inc. was evacuating 200 people from the jack-up rig Ocean Titan and two other Gulf rigs “out of an abundance of caution,” according to Les Van Dyke, director of investor relations for the Houston-based company. Anadarko, based in The Woodlands, Texas, said it was shutting all eight of its Gulf facilities and Hague-based Royal Dutch Shell Plc is evacuating workers from most of its Gulf operations and shutting in some production. Exxon Mobil, based in Irving, Texas, was evacuating 140 workers from Gulf platforms and shutting in 11,000 barrels a day of liquids production, as well as 60 million cubic feet of natural gas production. Switzerland-based Noble Corp. evacuated about 300 workers from three of five active rigs in the Gulf.

Houston-based ConocoPhillips evacuated all workers and shut in production from the Magnolia platform, which averaged daily output of 5,000 barrels of oil equivalent last year. Enbridge Inc. Garden Banks Gas Pipeline LLC and Stingray Pipeline Co. removed workers from natural gas platforms ahead of the storm. El Paso Corp. (EP)’s Southern Natural Gas Co. evacuated workers from two supply points, reducing gas production by about 43 million cubic feet a day.

Joe Bastardi, chief meteorologist for New York-based WeatherBell Analytics, compared the Gulf system to 1985’s Hurricane Juan, which spent five days over the water. Juan caused $1.5 billion in damage in Louisiana, the hurricane center said. The Terrebonne and South Lafourche levee districts in Louisiana have closed floodgates ahead of the storm, Jindal said in an e-mailed statement. The state Department of Wildlife and Fisheries is securing equipment and preparing response teams, he said.

‘On Alert’

“We’re closely monitoring the weather in the Gulf and our agencies are on alert and stand ready to assist coastal parishes if the system strengthens,” Jindal said. “We know from experience that it’s best to prepare for the worst and hope for the best.” In the Atlantic, Katia continued to move over the open water at tropical storm strength about 830 miles east of the northern Leeward Islands, the NHC said in an advisory at about 11 p.m. New York time yesterday. The storm’s maximum sustained winds fell to 70 miles per hour, down from 75 mph earlier, the center said. “Katia is forecast to regain hurricane strength during the next day or so,” the center said. “Swells generated by Katia will be affecting the Lesser Antilles by late Friday.” Katia was previously a Category 1 storm on the five-step Saffir-Simpson scale. It is the 11th named storm of the Atlantic hurricane season that runs from June through November.

Puerto Rico Path

The hurricane center’s forecast path shows Katia north of Puerto Rico by Sept. 6. Katia is forecast to turn north and out to sea eventually. A shift westward could bring it to land in easternCanada, AccuWeather Inc. said. Canada’s Atlantic region, a major gasoline supplier for the Northeast, exported 469,704 cubic meters, equivalent to 2.96 million barrels, of the fuel in May. The center is also monitoring a low-pressure system about 500 miles south of Halifax, Nova Scotia. The system is expected to begin moving northeastward at 10 to 15 mph and has a 40 percent chance of becoming a tropical cyclone in the next two days, according to the center’s weather outlook.

http://www.bloomberg...ical-storm.html

[Iceberg]

Katia definately back to Hurricane strength again and should be acknowledged as such by the NHC in the next advisory at 4.00pm.

GFS 06Z now skirts the N.Carolina banks and Rhode Island with Katia, but the westward shift is continuing.