Hurricane KATIA

maquiladora · 29-08-2011 9:55am #1

This should become Tropical Storm Katia later today and is forecast to become a hurricane in the next few days.

000
WTNT22 KNHC 290841
TCMAT2

TROPICAL DEPRESSION TWELVE FORECAST/ADVISORY NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
0900 UTC MON AUG 29 2011

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

TROPICAL DEPRESSION CENTER LOCATED NEAR 9.4N 26.3W AT 29/0900Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT 13 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1009 MB
MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

Storms that get classified this far east usually recurve out to sea but there has been some exceptions. Worth keeping an eye on.

TheInquisitor · 29-08-2011 10:55am

This has much longer to build up that Irene and also because it has started off at such a southern point it has exceptionally warm seas from which to grow. If it stays south for long enough this one could be much more dangerous to the USA than Irene was!

maquiladora · 29-08-2011 12:00pm

TheInquisitor wrote: »

If it stays south for long enough this one could be much more dangerous to the USA than Irene was!

At the moment its not looking like it will stay south. Would need a stronger ridge or something else that the models aren't currently showing to be a threat to the US, but its a long way off so who knows.

06Z GFS recurves it as a major. Bermuda and Canada more at risk if something like this came off.

munsterlegend · 29-08-2011 12:26pm

As a matter of interest is this an above average Hurricane season so far? or in line with previous years?

snowstreams · 29-08-2011 2:42pm

munsterlegend wrote: »

As a matter of interest is this an above average Hurricane season so far? or in line with previous years?

Its above average due to the number of tropical storms that have been named. However Irene was the only hurricane so far, so that part of the statistics isnt above normal.

maquiladora · 29-08-2011 6:43pm

Today is the 6-year anniversary Hurricane Katrina's landfall near New Orleans. Katia is the name that was selected to replace Katrina. And during the next 12 hours, TD 12 is forecast to become Tropical Storm Katia.

maquiladora · 29-08-2011 8:05pm

12Z ECM is on the 'roids.

Has TD12/'Katia' moving much faster and also further south than on the 0Z and and ends the run leaving Katia as an absolute monster.

Potential threat to NE US/Canada/Bermuda on that run.

(Don't take any of this too seriously. The models were showing Irene as a Gulf of Mexico storm at one point.

)

eilejh · 30-08-2011 4:25am

Latest discussion
http://www.nhc.noaa.gov/text/refresh/MIATCDAT2+shtml/300240.shtml?
000
WTNT42 KNHC 300240
TCDAT2

TROPICAL DEPRESSION TWELVE DISCUSSION NUMBER 4
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
1100 PM AST MON AUG 29 2011

AT THE TIME OF THE SATELLITE FIXES AT 00Z...A LARGE CURVED
CONVECTIVE BAND WRAPPED ABOUT HALF WAY AROUND THE CIRCULATION...
WHICH RESULTED IN SATELLITE INTENSITY ESTIMATES OF T2.5/35 KT FROM
SAB AND T2.0/30 KT WITH A DATA-T NUMBER OF 2.5/35 KT FROM TAFB.
HOWEVER...SINCE THAT TIME THE CURVED BAND HAS DISSIPATED...AND THE
CONVECTIVE PATTERN HAS DEVOLVED INTO MORE OF A SHEAR PATTERN. A
SMALL BURST OF DEEP CONVECTION HAS DEVELOPED OVER AND JUST WEST OF
THE CENTER...BUT ONE THUNDERSTORM DOES NOT MAKE A TROPICAL STORM.
THEREFORE...THE INTENSITY IS BEING HELD AT 30 KT FOR THIS ADVISORY.

THE INITIAL MOTION IS NOW 290/13 KT BASED ON A BLEND OF VISIBLE AND
MICROWAVE SATELLITE FIXES. THE GLOBAL AND REGIONAL MODELS ARE IN
EXCELLENT AGREEMENT ON A GENERAL WEST-NORTHWESTWARD MOTION OVER THE
NEXT 5 DAYS...BUT THERE ARE SPEED DIFFERENCES IN THE MODELS. THE
GFDL...UKMET...CANADIAN AND ECMWF MOVE THE DEPRESSION THE
FASTEST...WHEREAS THE GFS...HWRF...AND NOGAPS ARE SLOWER.
HOWEVER...THE TREND IN THE MOST RECENT MODEL RUNS HAS BEEN TO
WEAKEN THE MID/UPPER-LEVEL LOW NEAR 30N55W AND LIFT IT OUT TO THE
NORTHEAST SOONER THAN IN PREVIOUS RUNS. THIS RESULTS IN LESS OF A
WEAKNESS IN THE SUBTROPICAL RIDGE...WHICH IS ALSO FORECAST TO
CHANGE ITS CURRENT NORTH-SOUTH CONFIGURATION TO AN EAST-WEST
ORIENTATION BY 72 HOURS. THIS CHANGE IN THE STEERING FLOW SHOULD
KEEP THE CYCLONE MOVING ON A WEST-NORTHWESTWARD TRACK FOR THE NEXT
4 DAYS...AND THEN SLOW DOWN AND POSSIBLY TURN MORE WESTWARD BY DAY
5 AS A NARROW RIDGE DEVELOPS TO THE NORTH AND WEST OF THE SYSTEM.
SINCE THE DEPRESSION IS BASICALLY ON TRACK...THE NEW NHC FORECAST
IS JUST AN UPDATE AND EXTENSION OF THE PREVIOUS ADVISORY TRACK.

THE EROSION OF CONVECTIVE BANDING FEATURES HAS LIKELY BEEN DUE A
NARROW INTRUSION OF DRY AIR COMING IN THE FROM THE NORTHEAST.
HOWEVER...ALL AVAILABLE DIAGNOSTIC AND MODEL FORECAST DATA INDICATE
THAT THE CYCLONE IS SURROUNDED BY VERY MOIST MID-LEVEL AIR WITH
HUMIDITY VALUES OF 70 PERCENT OR HIGHER...WHICH SHOULD ALLOW FOR
DEEP CONVECTION TO RECOVER LATER TONIGHT AND FOR THE SYSTEM TO
REACH TROPICAL STORM STATUS WITHIN THE NEXT 6-12 HOURS. MODERATE
NORTHEASTERLY SHEAR IS ALSO FORECAST TO AFFECT THE CYCLONE FOR THE
NEXT 24 HOURS OR SO...WHICH SHOULD INHIBIT ANY RAPID DEVELOPMENT.
AFTER THAT...HOWEVER...THE SHEAR IS EXPECTED TO SHARPLY DECREASE...
AND AN UPPER-LEVEL ANTICYCLONE IS FORECAST TO DEVELOP OVER THE
SURFACE CIRCULATION. THIS IMPROVEMENT IN THE VENTILATION PROCESS
SHOULD ALLOW FOR THE CYCLONE TO AT LEAST STEADILY INTENSIFY AND
BECOME A HURRICANE IN 48-72 HOURS AS SUGGESTED BY THE SHIPS...
LGEM...HWRF...AND GFDL MODELS.

FORECAST POSITIONS AND MAX WINDS

INIT 30/0300Z 11.0N 30.0W 30 KT 35 MPH
12H 30/1200Z 11.8N 32.0W 35 KT 40 MPH
24H 31/0000Z 12.8N 34.7W 45 KT 50 MPH
36H 31/1200Z 13.9N 37.8W 50 KT 60 MPH
48H 01/0000Z 14.8N 41.5W 60 KT 70 MPH
72H 02/0000Z 16.4N 47.5W 70 KT 80 MPH
96H 03/0000Z 18.3N 52.9W 80 KT 90 MPH
120H 04/0000Z 20.0N 57.0W 90 KT 105 MPH

$$
FORECASTER STEWART

maquiladora · 30-08-2011 9:31am

Yep, looks like a slight delay on the upgrade to TS status, should happen later. today

Intensity forecasts. GFDL seems too aggresive. 160mph and still rising at 132 hours.

maquiladora · 30-08-2011 9:54am

Katia is born.

Tropical Storm KATIA
...NEW TROPICAL STORM MOVING QUICKLY WEST-NORTHWESTWARD ACROSS THE TROPICAL ATLANTIC...

5:00 AM AST Tue Aug 30
Location: 11.8°N 31.7°W
Max sustained: 40 mph
Moving: WNW at 17 mph
Min pressure: 1006 mb

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM

TROPICAL STORM KATIA DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
500 AM AST TUE AUG 30 2011

THE CONVECTIVE PATTERN OF THE CYCLONE HAS IMPROVED OVERNIGHT...WITH
A LARGE AREA OF COLD CLOUD TOPS NOW SITUATED TO THE WEST AND
SOUTHWEST OF THE ESTIMATED CENTER LOCATION. THE 06Z DVORAK
INTENSITY ESTIMATES FROM TAFB AND SAB WERE BOTH 2.5/35 KT...AND ON
THIS BASIS THE CYCLONE IS UPGRADED TO A TROPICAL STORM. THE
STRUCTURE OF KATIA IS CONSISTENT WITH THE 15-20 KT OF
EAST-NORTHEASTERLY SHEAR OVER THE CYCLONE ANALYZED BY THE SHIPS
MODEL AND UW-CIMSS. THIS SHEAR SHOULD DECREASE IN THE NEXT 12 HOURS
OR SO...AND AFTER THAT TIME STEADY INTENSIFICATION SHOULD COMMENCE
AS THE CYCLONE MOVES OVER PROGRESSIVELY HIGHER OCEAN HEAT CONTENT.
MOST OF THE INTENSITY GUIDANCE HAS TRENDED UPWARD THIS CYCLE...AND
THE OFFICIAL FORECAST HAS AS WELL. KATIA IS EXPECTED TO BE NEAR
HURRICANE STRENGTH WITHIN 36 TO 48 HOURS WITH CONTINUED
STRENGTHENING TO NEAR MAJOR HURRICANE STATUS BY THE END OF THE
PERIOD. THE NHC FORECAST IS CLOSE TO THE MULTI-MODEL CONSENSUS THAT
INCLUDES THE HFIP INTENSITY AIDS.

A TIMELY AMSR-E PASS FROM 0326Z WAS HELPFUL IN LOCATING THE CENTER
ON THE EASTERN EDGE OF THE DEEP CONVECTION...WHICH WAS A BIT NORTH
OF PREVIOUS ESTIMATES. THE INITIAL MOTION ESTIMATE IS 290/15...AS
KATIA CONTINUES TO BE STEERED WEST-NORTHWESTWARD BY THE SUBTROPICAL
RIDGE TO ITS NORTH. THE MODEL GUIDANCE IS IN GOOD AGREEMENT ON A
CONTINUATION OF THIS GENERAL MOTION THROUGH THE PERIOD AS THE
MID-LEVEL RIDGE BUILDS WESTWARD TO THE NORTH OF THE CYCLONE. AT
DAYS 4 AND 5...THE WESTERN EDGE OF THE RIDGE BEGINS TO WEAKEN AS A
MID-LEVEL TROUGH AMPLIFIES OVER THE WESTERN ATLANTIC...WHICH SHOULD
RESULT IN SOME DECREASE IN FORWARD SPEED. THE TRACK GUIDANCE
REMAINS TIGHTLY CLUSTERED BUT THERE ARE SOME FORWARD SPEED
DIFFERENCES...WITH THE UKMET AND GFDL MODELS ON THE FAST SIDE OF
THE GUIDANCE AND THE GFS CONTINUING TO BE A SLOW OUTLIER. FOR THIS
CYCLE THE MODELS HAVE TRENDED FASTER DURING THE FIRST 72 HOURS...
AND SO HAS THE OFFICIAL FORECAST. OTHERWISE...THE NHC FORECAST IS
VERY CLOSE TO THE PREVIOUS ONE AND LIES NEAR OR A LITTLE TO THE
RIGHT OF THE TVCA MULTI-MODEL CONSENSUS THROUGH THE PERIOD.

FORECAST POSITIONS AND MAX WINDS

INIT 30/0900Z 11.8N 31.7W 35 KT 40 MPH
12H 30/1800Z 12.5N 33.7W 40 KT 45 MPH
24H 31/0600Z 13.5N 36.8W 50 KT 60 MPH
36H 31/1800Z 14.4N 40.2W 60 KT 70 MPH
48H 01/0600Z 15.3N 43.7W 70 KT 80 MPH
72H 02/0600Z 17.0N 49.5W 80 KT 90 MPH
96H 03/0600Z 18.5N 54.0W 90 KT 105 MPH
120H 04/0600Z 20.5N 58.0W 100 KT 115 MPH

munsterlegend · 30-08-2011 10:36am

Thanks Maquiladora for the updates.

Haven't really followed hurricane season before. Is it too early to say the likely path?

maquiladora · 30-08-2011 11:00am

munsterlegend wrote: »

Thanks Maquiladora for the updates.

Haven't really followed hurricane season before. Is it too early to say the likely path?

There is good model agreement on the track for the next 3 days or so, beyond that then it's a bit too early to say.

Iancar29 · 30-08-2011 1:07pm

I THink Katia will become the first Cat. 5 of the season!
SO much fuel ahead of it..

maquiladora · 30-08-2011 9:58pm

( Could a mod please update the thread title? Thanks)

...KATIA CONTINUES TO STRENGTHEN OVER THE EASTERN TROPICAL ATLANTIC...

5:00 PM AST Tue Aug 30
Location: 12.7°N 35.4°W
Max sustained: 60 mph
Moving: WNW at 20 mph
Min pressure: 997 mb

000
WTNT42 KNHC 302040
TCDAT2

TROPICAL STORM KATIA DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
500 PM AST TUE AUG 30 2011

KATIA CONTINUES TO LOOK MORE IMPRESSIVE ON SATELLITE IMAGES...WITH
INCREASING CENTRAL DEEP CONVECTION AND WELL-DEFINED BANDING
FEATURES. UPPER-LEVEL OUTFLOW IS BECOMING WELL ESTABLISHED TO THE
NORTH...WEST...AND SOUTH OF THE STORM. DVORAK INTENSITY ESTIMATES
HAVE INCREASED TO 45 KT AND 55 KT FROM SAB AND TAFB RESPECTIVELY...
AND THE ADVISORY INTENSITY IS SET AT 50 KT. KATIA WILL BE MOVING
OVER SEA SURFACE TEMPERATURES NEAR 28 DEG C AND IN A LOW SHEAR
ENVIRONMENT FOR THE NEXT FEW DAYS...SO STEADY STRENGTHENING APPEARS
TO BE LIKELY. THE OFFICIAL INTENSITY FORECAST IS A BLEND OF THE
STATISTICAL AND DYNAMICAL MODEL GUIDANCE.

THE INITIAL MOTION...285/17...IS ONLY A LITTLE FASTER THAN IN THE
PREVIOUS PACKAGE. THE TRACK FORECAST AND FORECAST PHILOSOPHY ARE
BASICALLY UNCHANGED. KATIA SHOULD CONTINUE TO MOVE
WEST-NORTHWESTWARD TO THE SOUTH OF THE SUBTROPICAL RIDGE FOR THE
NEXT SEVERAL DAYS. NEAR THE END OF THE FORECAST PERIOD...A WEAKNESS
IN THE RIDGE PRODUCED BY A TROUGH OVER THE WESTERN ATLANTIC IS
EXPECTED TO INDUCE A GRADUAL TURN TO THE RIGHT WITH A DECREASE IN
FORWARD SPEED. THE OFFICIAL TRACK FORECAST IS CLOSE TO THE
MULTI-MODEL CONSENSUS AND SOUTH OF THE LATEST ECMWF SOLUTION.

THE WIND RADII HAVE BEEN EXPANDED ON THE BASIS OF AN ASCAT PASS FROM
EARLIER TODAY.

FORECAST POSITIONS AND MAX WINDS

INIT 30/2100Z 12.7N 35.4W 50 KT 60 MPH
12H 31/0600Z 13.3N 37.9W 60 KT 70 MPH
24H 31/1800Z 14.1N 41.1W 65 KT 75 MPH
36H 01/0600Z 14.9N 44.4W 70 KT 80 MPH
48H 01/1800Z 15.7N 47.5W 80 KT 90 MPH
72H 02/1800Z 17.5N 52.5W 90 KT 105 MPH
96H 03/1800Z 19.5N 56.5W 100 KT 115 MPH
120H 04/1800Z 21.5N 60.5W 105 KT 120 MPH

$$
FORECASTER PASCH

eilejh · 31-08-2011 1:33am

Cone of Uncertainty

http://www.nhc.noaa.gov/refresh/graphics_at2+shtml/203913.shtml?5-daynl#contents

eilejh · 31-08-2011 5:28am

11 o'clock Discussion
http://www.nhc.noaa.gov/text/refresh/MIATCDAT2+shtml/310238.shtml

00
WTNT42 KNHC 310238
TCDAT2

TROPICAL STORM KATIA DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
1100 PM AST TUE AUG 30 2011

A SERIES OF MICROWAVE IMAGES DURING THE LATE AFTERNOON SHOWED
THAT THE CENTER OF KATIA WAS LOCATED NEAR THE NORTHWESTERN EDGE
OF A BAND OF DEEP CONVECTION. SINCE THAT TIME...ANOTHER BAND OF
CONVECTION HAS DEVELOPED TO THE SOUTH AND WEST OF THE CENTER AND IT
APPEARS THAT THE CYCLONE IS GRADUALLY BECOMING BETTER ORGANIZED.
HOWEVER...THE LATEST DVORAK INTENSITY ESTIMATES WERE UNCHANGED FROM
1800 UTC...AND THE INITIAL INTENSITY REMAINS 50 KT. KATIA IS
FORECAST TO BE IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY WARM
WATER AND VERY LOW SHEAR DURING THE NEXT SEVERAL DAYS. STEADY
STRENGTHENING IS THEREFORE EXPECTED AND THE OFFICIAL FORECAST SHOWS
KATIA BECOMING A HURRICANE IN ABOUT 24 HOURS...AND A MAJOR
HURRICANE IN 2-3 DAYS. THE NHC FORECAST IS A BLEND OF THE VARIOUS
INTENSITY AIDS THROUGH 72 HOURS...BUT IS CLOSER TO THE MORE
AGGRESSIVE HWRF/GFDL GUIDANCE AT 96 AND 120 HOURS.

KATIA IS MOVING BRISKLY WEST-NORTHWESTWARD OR 285/19 KT. KATIA
SHOULD CONTINUE ON A WEST-NORTHWEST HEADING TO THE SOUTH OF THE
SUBTROPICAL RIDGE FOR THE NEXT SEVERAL DAYS. LATE IN THE FORECAST
PERIOD...KATIA IS EXPECTED TO SLOW DOWN AND TURN TOWARD THE
NORTHWEST AS A TROUGH OVER THE WESTERN ATLANTIC INDUCES A WEAKNESS
IN THE RIDGE. THE UPDATED FORECAST IS VERY SIMILAR TO THE PREVIOUS
NHC TRACK THROUGH 72 HOURS...BUT IT HAS BEEN ADJUSTED TO THE RIGHT
AT DAYS 4 AND 5 TO BE IN BETTER AGREEMENT WITH THE GFS AND ECMWF
MODELS.

FORECAST POSITIONS AND MAX WINDS

INIT 31/0300Z 13.3N 37.5W 50 KT 60 MPH
12H 31/1200Z 14.0N 40.1W 60 KT 70 MPH
24H 01/0000Z 14.8N 43.4W 70 KT 80 MPH
36H 01/1200Z 15.5N 46.5W 80 KT 90 MPH
48H 02/0000Z 16.5N 49.3W 90 KT 105 MPH
72H 03/0000Z 18.5N 54.0W 100 KT 115 MPH
96H 04/0000Z 20.5N 57.5W 110 KT 125 MPH
120H 05/0000Z 23.0N 60.5W 110 KT 125 MPH

$$
FORECASTER BROWN

dexter647 · 31-08-2011 10:03am

Looks like we could have hurricane Katia later today..

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.

maquiladora · 31-08-2011 12:27pm

GFS ensembles for Katia. Nova Scotia/Newfoundland hit looking likely here. Bermuda will be watching closely too.

munsterlegend · 31-08-2011 12:41pm

maquiladora wrote: »

GFS ensembles for Katia. Nova Scotia/Newfoundland hit looking likely here. Bermuda will be watching closely too.

there is one line there which brings it very close to the east coast of america? is that highly unlikely?

200motels · 31-08-2011 12:51pm

Could anyone post a link for all the different models for the atlantic as I can't seem to find them on the net. Thanks

maquiladora · 31-08-2011 1:29pm

munsterlegend wrote: »

there is one line there which brings it very close to the east coast of america? is that highly unlikely?

With ensembles the thing to look for is the overall trend, so yes you can pretty much ignore those stray outliers.

maquiladora · 31-08-2011 1:30pm

200motels wrote: »

Could anyone post a link for all the different models for the atlantic as I can't seem to find them on the net. Thanks

http://raleighwx.americanwx.com/models.html

maquiladora · 31-08-2011 3:59pm

...KATIA LIKELY TO BECOME A HURRICANE LATER TODAY...

11:00 AM AST Wed Aug 31
Location: 14.2°N 40.8°W
Max sustained: 65 mph
Moving: WNW at 21 mph
Min pressure: 994 mb

000
WTNT42 KNHC 311435
TCDAT2

TROPICAL STORM KATIA DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
1100 AM AST WED AUG 31 2011

KATIA REMAINS A WELL-ORGANIZED TROPICAL CYCLONE WITH DISTINCT
BANDING FEATURES AND A DEVELOPING CENTRAL DENSE OVERCAST. DVORAK
CLASSIFICATIONS ARE T3.5 FROM BOTH AGENCIES AND THE CURRENT
INTENSITY IS HELD AT 55 KT. THE SYSTEM HAS A WELL-DEFINED
UPPER-LEVEL OUTFLOW PATTERN. AT THE MOMENT...IT DOES NOT APPEAR
THAT THE DRY AIR ADJACENT TO THE STORM IS BEING ENTRAINED INTO THE
CIRCULATION. THE SHIPS MODEL INDICATES THAT VERTICAL SHEAR WILL BE
WEAK FOR THE NEXT DAY OR TWO WHICH SHOULD FAVOR STRENGTHENING AT
LEAST FOR THE EARLIER PART OF THE FORECAST PERIOD. A LARGE
UPPER-LEVEL LOW TO THE NORTHWEST OF KATIA COULD PLAY A ROLE IN THE
INTENSITY OF THE TROPICAL CYCLONE IN THE LATTER PART OF THE
FORECAST PERIOD. AS NOTED EARLIER...SOME OF THE GLOBAL MODELS
SUGGEST THAT THIS LOW COULD PRODUCE INCREASING SOUTHWESTERLY SHEAR
IN 4 TO 5 DAYS WHICH WOULD INHIBIT INTENSIFICATION. THE OFFICIAL
INTENSITY FORECAST IS THE SAME AS THAT FROM THE PREVIOUS ADVISORY
AND IS SLIGHTLY ABOVE THE NUMERICAL CONSENSUS.

KATIA CONTINUES TO MOVE SWIFTLY TOWARD THE WEST-NORTHWEST OR 285/18
TO THE SOUTH OF A MID-TROPOSPHERIC SUBTROPICAL ANTICYCLONE. THE
DYNAMICAL GUIDANCE IS IN RATHER GOOD AGREEMENT ON A CONTINUATION OF
THIS WEST-NORTHWESTWARD TRACK FOR THE NEXT COUPLE OF DAYS WITH SOME
DECELERATION AS THE TROPICAL CYCLONE NEARS A WEAKNESS IN THE RIDGE.
IN THE LATTER PART OF THE FORECAST PERIOD...MOST OF THE GUIDANCE
SHOWS A TURN TOWARD THE NORTHWEST AS KATIA APPROACHES THE SOUTHWEST
SIDE OF THE SUBTROPICAL ANTICYCLONE. THE OFFICIAL TRACK FORECAST
FOR THIS ADVISORY PACKAGE IS AN UPDATE OF THE PREVIOUS ONE AND IS
CLOSE TO THE VARIOUS MODEL CONSENSUS TRACKS.

FORECAST POSITIONS AND MAX WINDS

INIT 31/1500Z 14.2N 40.8W 55 KT 65 MPH
12H 01/0000Z 14.7N 43.3W 65 KT 75 MPH
24H 01/1200Z 15.4N 46.3W 75 KT 85 MPH
36H 02/0000Z 16.2N 48.7W 85 KT 100 MPH
48H 02/1200Z 17.3N 51.0W 90 KT 105 MPH
72H 03/1200Z 19.5N 54.5W 95 KT 110 MPH
96H 04/1200Z 21.5N 57.5W 100 KT 115 MPH
120H 05/1200Z 23.5N 60.5W 105 KT 120 MPH

$$
FORECASTER PASCH

dsmythy · 31-08-2011 8:02pm

Looks like Lee could join the party in the Gulf some time soon to supplement Katia.

31-08-2011 8:22pm

Interesting that they named it Katia. Which is a form of Yekaterina, which sounds like Katrina.

irishgeo · 31-08-2011 8:37pm

Jake1 wrote: »

Interesting that they named it Katia. Which is a form of Yekaterina, which sounds like Katrina.

katia is the name picked to replace katrina on the hurricane list as katrina cant be used again.

Derfil · 31-08-2011 8:47pm

irishgeo wrote: »

katia is the name picked to replace katrina on the hurricane list as katrina cant be used again.

Once the reach notoriety and kill a certain number they're retired. Grim. :mad:

irishgeo · 31-08-2011 8:51pm

what could happen if katia runs into the area in yellow thats in the gulf or vice versa.

have 2 hurricanes/tropical storms ever collided?

maquiladora · 31-08-2011 8:52pm

12 ECM showing Katia and "Lee" in the Gulf of Mexico.

Interesting the 12Z ECM brings Katia a lot further west and south before recurving at the end of the run. Some other 12Z models have brought Katia further west too, might be the start of a new trend, have to wait and see.

31-08-2011 8:52pm

Yes, Im aware that they retire the names, my point was, and I should have made it clearer maybe, was that I thought it strange they picked a name so like Katrina, which killed over 1800. Just thought it a bit grim.

maquiladora · 31-08-2011 9:03pm

irishgeo wrote: »

what could happen if katia runs into the area in yellow thats in the gulf or vice versa.

have 2 hurricanes/tropical storms ever collided?

I think its very unlikely that Katia will end up heading for Gulf of Mexico. The area on that map in the Gulf where a new storm may be the forming (most models show it developing over the next few days). Because Katia is so far away from the Gulf, the future "Lee" storm will already have gone through its lifecycle and would have already made landfall by the time Katia got there, if Katia was going in that direction, nothing suggests it will.

The answer to your second question is called the Fujiwhara effect!

http://en.wikipedia.org/wiki/Fujiwhara_effect

unitedrover · 31-08-2011 9:11pm

irishgeo wrote: »

have 2 hurricanes/tropical storms ever collided?

Ive no knowledge of storm formations but would they merge together to form a superstorm? sounds a bit like The Day After Tommorrow with this.

Hopefully someone can correct me on this

irishgeo · 31-08-2011 9:11pm

maquiladora wrote: »

I think its very unlikely that Katia will end up heading for Gulf of Mexico. The area on that map in the Gulf where a new storm may be the forming (most models show it developing over the next few days). Because Katia is so far away from the Gulf, the future "Lee" storm will already have gone through its lifecycle and would have already made landfall by the time Katia got there, if Katia was going in that direction, nothing suggests it will.

The answer to your second question is called the Fujiwhara effect!
http://en.wikipedia.org/wiki/Fujiwhara_effect

reading that is says hurricane iris was put off track by the fujiwhara effect and ended in the uk. is this the hurricane michael fish got so badly wrong?

maquiladora · 31-08-2011 9:24pm

irishgeo wrote: »

reading that is says hurricane iris was put off track by the fujiwhara effect and ended in the uk. is this the hurricane michael fish got so badly wrong?

Iris was 1995. The storm you are thinking of was in 1987.

http://en.wikipedia.org/wiki/1987_storm

maquiladora · 31-08-2011 9:43pm

...KATIA ALMOST A HURRICANE...

5:00 PM AST Wed Aug 31
Location: 14.6°N 42.6°W
Max sustained: 70 mph
Moving: WNW at 20 mph
Min pressure: 990 mb

000
WTNT42 KNHC 311435
TCDAT2

TROPICAL STORM KATIA DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
1100 AM AST WED AUG 31 2011

KATIA REMAINS A WELL-ORGANIZED TROPICAL CYCLONE WITH DISTINCT
BANDING FEATURES AND A DEVELOPING CENTRAL DENSE OVERCAST. DVORAK
CLASSIFICATIONS ARE T3.5 FROM BOTH AGENCIES AND THE CURRENT
INTENSITY IS HELD AT 55 KT. THE SYSTEM HAS A WELL-DEFINED
UPPER-LEVEL OUTFLOW PATTERN. AT THE MOMENT...IT DOES NOT APPEAR
THAT THE DRY AIR ADJACENT TO THE STORM IS BEING ENTRAINED INTO THE
CIRCULATION. THE SHIPS MODEL INDICATES THAT VERTICAL SHEAR WILL BE
WEAK FOR THE NEXT DAY OR TWO WHICH SHOULD FAVOR STRENGTHENING AT
LEAST FOR THE EARLIER PART OF THE FORECAST PERIOD. A LARGE
UPPER-LEVEL LOW TO THE NORTHWEST OF KATIA COULD PLAY A ROLE IN THE
INTENSITY OF THE TROPICAL CYCLONE IN THE LATTER PART OF THE
FORECAST PERIOD. AS NOTED EARLIER...SOME OF THE GLOBAL MODELS
SUGGEST THAT THIS LOW COULD PRODUCE INCREASING SOUTHWESTERLY SHEAR
IN 4 TO 5 DAYS WHICH WOULD INHIBIT INTENSIFICATION. THE OFFICIAL
INTENSITY FORECAST IS THE SAME AS THAT FROM THE PREVIOUS ADVISORY
AND IS SLIGHTLY ABOVE THE NUMERICAL CONSENSUS.

KATIA CONTINUES TO MOVE SWIFTLY TOWARD THE WEST-NORTHWEST OR 285/18
TO THE SOUTH OF A MID-TROPOSPHERIC SUBTROPICAL ANTICYCLONE. THE
DYNAMICAL GUIDANCE IS IN RATHER GOOD AGREEMENT ON A CONTINUATION OF
THIS WEST-NORTHWESTWARD TRACK FOR THE NEXT COUPLE OF DAYS WITH SOME
DECELERATION AS THE TROPICAL CYCLONE NEARS A WEAKNESS IN THE RIDGE.
IN THE LATTER PART OF THE FORECAST PERIOD...MOST OF THE GUIDANCE
SHOWS A TURN TOWARD THE NORTHWEST AS KATIA APPROACHES THE SOUTHWEST
SIDE OF THE SUBTROPICAL ANTICYCLONE. THE OFFICIAL TRACK FORECAST
FOR THIS ADVISORY PACKAGE IS AN UPDATE OF THE PREVIOUS ONE AND IS
CLOSE TO THE VARIOUS MODEL CONSENSUS TRACKS.

FORECAST POSITIONS AND MAX WINDS

INIT 31/1500Z 14.2N 40.8W 55 KT 65 MPH
12H 01/0000Z 14.7N 43.3W 65 KT 75 MPH
24H 01/1200Z 15.4N 46.3W 75 KT 85 MPH
36H 02/0000Z 16.2N 48.7W 85 KT 100 MPH
48H 02/1200Z 17.3N 51.0W 90 KT 105 MPH
72H 03/1200Z 19.5N 54.5W 95 KT 110 MPH
96H 04/1200Z 21.5N 57.5W 100 KT 115 MPH
120H 05/1200Z 23.5N 60.5W 105 KT 120 MPH

$$
FORECASTER PASCH

eilejh · 01-09-2011 1:39am

KATIA Discussion
http://www.storm2k.org/phpbb2/viewtopic.php?f=59&t=111658&st=0&sk=t&sd=a&start=620

KATIA Models thread
http://www.storm2k.org/phpbb2/viewtopic.php?f=59&t=111659&start=620

93L (Future LEE)
Discussion
http://www.storm2k.org/phpbb2/viewtopic.php?f=59&t=111727&st=0&sk=t&sd=a&start=80

93L Models thread
http://www.storm2k.org/phpbb2/viewtopic.php?f=59&t=111729&start=160

eilejh · 01-09-2011 1:44am

NATIONAL HURRICANE CENTER
TROPICAL STORM KATIA PUBLIC ADVISORY
8:00 Discussion

000
WTNT32 KNHC 312038
TCPAT2

BULLETIN
TROPICAL STORM KATIA ADVISORY NUMBER 11
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
500 PM AST WED AUG 31 2011

...KATIA ALMOST A HURRICANE...

SUMMARY OF 500 PM AST...2100 UTC...INFORMATION

LOCATION...14.6N 42.6W
ABOUT 1285 MI...2070 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 20 MPH...32 KM/H
MINIMUM CENTRAL PRESSURE...990 MB...29.23 INCHES

WATCHES AND WARNINGS

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

DISCUSSION AND 48-HOUR OUTLOOK

AT 500 PM AST...2100 UTC...THE CENTER OF TROPICAL STORM KATIA WAS
LOCATED NEAR LATITUDE 14.6 NORTH...LONGITUDE 42.6 WEST. KATIA IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 20 MPH...32 KM/H...AND THIS
MOTION WITH A GRADUAL SLOWING OF FORWARD SPEED IS EXPECTED OVER THE
NEXT 48 HOURS.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 70 MPH...110
KM/H...WITH HIGHER GUSTS. ADDITIONAL STRENGTHENING IS FORECAST
DURING THE NEXT 48 HOURS...AND KATIA IS LIKELY TO BECOME A
HURRICANE TONIGHT.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 125 MILES...205 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB...29.23 INCHES.

eilejh · 01-09-2011 1:48am

http://www.ssd.noaa.gov/goes/flt/t2/flash-vis.html

http://www.ssd.noaa.gov/goes/flt/t2/flash-rgb.html

http://www.ssd.noaa.gov/goes/flt/t2/flash-rb.html

eilejh · 01-09-2011 1:50am

Satellite Images
http://www.ssd.noaa.gov/PS/TROP/trop-atl.html

Katia is beautiful....looks like an embryo wrapping up.

eilejh · 01-09-2011 3:55am

Hurricane KATIA RSS Feed icon Storm Archive
...KATIA BECOMES THE SECOND HURRICANE OF THE SEASON...
11:00 PM AST Wed Aug 31
Location: 15.0°N 44.4°W
Max sustained: 75 mph
Moving: WNW at 20 mph
Min pressure: 987 mb
Public
Advisory
#12

dermiek · 01-09-2011 4:22am

From NOAA:

...Katia Becomes Second Hurricane of Atlantic Season... Published: Wed, 31 Aug 2011 22:59:58 EDT Katia has strengthened and is now a hurricane —the second one of the 2011 Atlantic season. At 11:00 p.m. EDT, the center of Hurricane Katia was located near latitude 15.0 north, longitude 44.4 west, or about 1,165 miles east of the Leeward Islands. Katia is moving toward the west-northwest near 20 mph and this motion, with a gradual slowing of forward speed, is expected over the next 48 hours. Maximum sustained winds have increased to near 75 mph, with higher gusts. Katia is a Category One hurricane on the Saffir-Simpson hurricane wind scale. Additional strengthening is forecast during the next 48 hours and Katia could become a major hurricane by the weekend.

http://www.weather.gov/

pauldry · 01-09-2011 10:43am

unitedrover wrote: »

Ive no knowledge of storm formations but would they merge together to form a superstorm? sounds a bit like The Day After Tommorrow with this.

Hopefully someone can correct me on this

A lot of Low Pressure systems combine together in mid Atlantic and only form secondary lows usually nothing major

maquiladora · 01-09-2011 12:29pm

...KATIA CHANGES LITTLE IN STRENGTH DURING THE PAST SEVERAL HOURS...

5:00 AM AST Thu Sep 1
Location: 15.2°N 45.9°W
Max sustained: 75 mph
Moving: W at 20 mph
Min pressure: 987 mb

200motels · 01-09-2011 1:25pm

Is this hurricane just going to blow itself out and wander around the Atlantic or will it hit land as a hurricane.

maquiladora · 01-09-2011 2:01pm

200motels wrote: »

Is this hurricane just going to blow itself out and wander around the Atlantic or will it hit land as a hurricane.

It will almost certainly miss the Lesser Antilles to the northwest but beyond that is too early to know for sure because the models become too unreliable at that range. Most storms in the past that were in Katia's position ended up recurving back out to sea, so based on that the chances are it will do the same, but it's just too early to say for sure.

TheInquisitor · 01-09-2011 2:28pm

The only thing in its favour right now is its tracking directly west at the moment. In fact lots of the models are now disagreeing with each other now. Some suggesting it curves up and out into the Atlantic others now starting to think it might touch Florida. But again thats days away and everything can change.

The gulf is the interesting development at the moment. It seems to be near stationary and only moving very slowly northward. Winds are expected to become favorable for development later today and in those warm waters storms can grow very quickly!

maquiladora · 01-09-2011 3:54pm

11:00 AM AST Thu Sep 1
Location: 15.5°N 47.5°W
Max sustained: 75 mph
Moving: W at 18 mph
Min pressure: 987 mb

000
WTNT42 KNHC 011450
TCDAT2

HURRICANE KATIA DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
1100 AM AST THU SEP 01 2011

KATIA HAS CHANGED LITTLE IN STRUCTURE DURING THE LAST SEVERAL HOURS.
BASED ON MICROWAVE DATA...THE LOW-LEVEL CENTER IS LOCATED NEAR THE
WESTERN PERIPHERY OF THE CORE CONVECTION. A CURVED BAND STILL
EXISTS OVER THE SOUTHERN SEMICIRCLE OF THE STORM...BUT CLOUD TOPS
HAVE BEEN WARMING IN THIS BAND DURING THE PAST FEW HOURS. THE
INITIAL WIND SPEED REMAINS AT 65 KT FOR THIS ADVISORY...IN
AGREEMENT WITH THE LATEST SATELLITE CLASSIFICATIONS.

SOUTHWESTERLY SHEAR OF ABOUT 15 KT...AS ANALYZED BY UW-CIMSS...IS
CURRENTLY AFFECTING KATIA. THIS SHEAR IS ASSOCIATED WITH AN
UPPER-LEVEL LOW LOCATED TO THE NORTHWEST OF THE HURRICANE. THE
UPPER LOW IS EXPECTED TO CONTINUE TO IMPOSE MODERATE SHEAR OVER
KATIA FOR ANOTHER 24 TO 36 HOURS. IN ADDITION...SOME DRY AIR
APPEARS TO BE ENTRAINING INTO THE CIRCULATION OF KATIA AND
THIS...IN COMBINATION WITH THE AFOREMENTIONED SHEAR...COULD INHIBIT
SIGNIFICANT DEVELOPMENT IN THE SHORT-TERM. BEYOND 36 HOURS...THE
GLOBAL MODELS SHOW THE UPPER LOW LIFTING OUT...CREATING A MORE
FAVORABLE UPPER-LEVEL WIND PATTERN. THEREFORE...STEADY
STRENGTHENING IS FORECAST IN THE LONGER RANGE. THE OFFICIAL
FORECAST IS LOWERED SLIGHTLY FROM THE PREVIOUS ONE IN THE
SHORT-TERM...BUT STILL BRINGS KATIA TO A MAJOR HURRICANE IN A FEW
DAYS.

KATIA IS MOVING WESTWARD AT 16 KT TO THE SOUTH OF A SUBTROPICAL
HIGH. THE HURRICANE IS EXPECTED TO SLOW DOWN AND TURN TO THE
WEST-NORTHWEST DURING THE NEXT 12-24 HOURS AS IT APPROACHES A
WEAKNESS IN THE RIDGE. THE MODEL GUIDANCE BECOMES VERY DIVERGENT IN
4 TO 5 DAYS WITH THE UKMET...NOGAPS...AND GFDL MODELS ON THE SOUTH
SIDE OF THE ENVELOPE AND THE GFS...ECMWF...AND HWRF MODELS ON THE
NORTH SIDE. THIS SPREAD APPEARS TO BE ASSOCIATED WITH THE STRENGTH
OF A TROUGH MOVING OVER THE NORTHEASTERN UNITED STATES AND THE
POSITION OF THE SUBTROPICAL HIGH. THE OFFICIAL TRACK FORECAST IS
ONLY NUDGED A LITTLE TO THE LEFT...IN PART BECAUSE OF THE INITIAL
MOTION AND POSITION...AND IS VERY NEAR THE MULTI-MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INIT 01/1500Z 15.5N 47.5W 65 KT 75 MPH
12H 02/0000Z 16.1N 49.5W 70 KT 80 MPH
24H 02/1200Z 17.0N 51.7W 75 KT 85 MPH
36H 03/0000Z 18.0N 53.4W 85 KT 100 MPH
48H 03/1200Z 19.0N 55.0W 95 KT 110 MPH
72H 04/1200Z 20.8N 58.0W 100 KT 115 MPH
96H 05/1200Z 22.3N 61.0W 105 KT 120 MPH
120H 06/1200Z 23.8N 64.0W 105 KT 120 MPH

$$
FORECASTER CANGIALOSI/ZELINSKY

Su Campu · 01-09-2011 6:41pm

If I were in Bermuda I'd be watching things very carefully. The GFS earlier had an almost direct hit. It certainly looks like any hit would be more likely to be on the storm's bad side as it's more and more likely to pass to the west of the country. It's been throwing up surprises for even the NHC, though, so it's all to play for.

unitedrover · 01-09-2011 6:56pm

It would be tough living in them islands during hurricane season. Most of them places are very poor too.

maquiladora · 01-09-2011 7:35pm

Interesting difference between the GFS and some of the other models.

And the updated 12Z :

GFS more west but still the furthest north after a few days.

Wertz · 01-09-2011 7:36pm

TheInquisitor wrote: »

The gulf is the interesting development at the moment. It seems to be near stationary and only moving very slowly northward. Winds are expected to become favorable for development later today and in those warm waters storms can grow very quickly!

That'll be a monster if it starts spinning and doesn't get up speed....so much moisture and inflow from W GoM on the water vapour images. Could basically make landfall anywhere.

http://www.goes.noaa.gov/HURRLOOPS/gulfwv.html

I know this is the katia thread but if/when this forms it'll be making landfall before katia I reckon...

[edit] Also a large area of spin evident a few hundred miles ESE of cape Haterras, not sure if it's tropical...

Hurricane KATIA

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