ATL: KATIA - Post Tropical - Discussion

[LeeNess87]

Thanks to all for all your detailed responses to my newbie questions!! I have another question. I'm pretty bad at this. So there is a weakness/trough at 65W that might allow the storm to recurve? Are there pressure areas along the conus that would push Katia into this 65W area. I am sorry if this sounds ridiculous to some of you haha VERY new.

[Extratropical94]

Does anyone know what the current dvorak number for Katia is?

3.0/3.0 (45 knots) at 1745 UTC.

Advanced Dvorak numbers are at 3.3 and 3.4 (51 and 53 knots)

Edit: You can look 'em up here: http://www.ssd.noaa.gov/PS/TROP/tdpositions.html
And these ones are for the ADT: http://www.ssd.noaa.gov/PS/TROP/adt.html and http://tropic.ssec.wisc.edu/real-time/adt/adt.html

[BigA]

Beautiful developing storm. Looks to be moving between W and WNW at the moment.

Here's a little graphic I created of the storm with the forecast points and where I think the center is based on the recent microwave imagery of the developing eyewall.



Uploaded with ImageShack.us

[Aric Dunn]

One of the GFS ensembles take it westward toward Florida/GOM...

Plus, that darn XTRP hits us almost every time!

(yes, I know it isn't a model)

which is why it still needs to be watched.. still dont think the models have the timing quite right or the strength of that trough

[Jevo]

Current steering



Uploaded with ImageShack.us

[cycloneye]

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

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


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...12.7N 35.4W
ABOUT 750 MI...1210 KM W OF THE SOUTHERNMOST CAPE VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 20 MPH...32 KM/H
MINIMUM CENTRAL PRESSURE...997 MB...29.44 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 12.7 NORTH...LONGITUDE 35.4 WEST. KATIA IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 20 MPH...32 KM/H...AND THIS
GENERAL MOTION IS EXPECTED TO CONTINUE OVER THE NEXT 48 HOURS.

SATELLITE IMAGES INDICATE THAT THE MAXIMUM SUSTAINED WINDS HAVE
INCREASED TO NEAR 60 MPH...95 KM/H...WITH HIGHER GUSTS. CONTINUED
STRENGTHENING IS FORECAST...AND KATIA COULD BECOME A HURRICANE
TOMORROW.

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

ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB...29.44 INCHES.


HAZARDS AFFECTING LAND
----------------------
NONE.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1100 PM AST.

$$
FORECASTER PASCH






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

[KWT]

does look classic looking at the images at the moment, I suspect its going to be well on its way to being a major by the end of this week.

[AHS2011]

60 MPH storm with 997 MB as pressure.

[theweatherwatch]

Here are my current thoughts on Katia!

http://www.theweatherwatch.org/?p=89

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[cycloneye]

5 PM Track touches with the cone the extreme NE Leeward islands.



Saved image.

[Cryomaniac]

Very much getting a classic look.

The following is the opinion of Cryomaniac and is not based on any evidence, meteorological or otherwise, as such it shouldn't be used for any purpose.

It looks like it's south of the forecast track to me, which presumably means that it will go slightly further west. I think the track will be interesting to follow though.

[Lowpressure]

I am sometimes amazed by how much faith some posters place in long range models. Irene was originally forecast to be a South Florida hit, and it hit NC, a huge miss. Until is gets within 72 hours or it has environmental Gulf stream data, it is a cone, that is all. Those saying this is a fish already are just posting to get there number higher. I understand opinions and this is a discussion board. We always say "how did the model not learn" when some of us are just as bad.

[Jevo]

One of the GFS ensembles take it westward toward Florida/GOM...

Plus, that darn XTRP hits us almost every time!

(yes, I know it isn't a model)

which is why it still needs to be watched.. still dont think the models have the timing quite right or the strength of that trough

I agree Aric... and it high time Katia gets the coveted

[Jevo]

With the 5PM update... Use of the stamp has now been authorized

[meriland23]

Looking at the 5 day PP just updated on NHC, I compared it side by side to their previous estimate at their 11am PP. Seems they are favoring a slight westward movement around 63W.

[Time_Zone]

Does this thing have the potential to possibly reach Cat 5 strength for a short time? I know this is a ridiculous question given how early it is...but its been a long time since theres been a cat 5 out in the atlantic.

[Jevo]

18Z GFS should be ramping up here shortly..

Hey Aric where is that nifty site that you have that loops that NHC forecast cones

[Lowpressure]

Does this thing have the potential to possibly reach Cat 5 strength for a short time? I know this is a ridiculous question given how early it is...but its been a long time since theres been a cat 5 out in the atlantic.

I suppose it is possible. It is hard to predict a Cat 5. This year it seems as thought there is always at least one inhibiting factor involved so far. Katia looks to have almost ideal conditions for a few days. Poleward outflow would be first big indicator I would think. She will be strong, just how strong is the question.

[meriland23]

Does this thing have the potential to possibly reach Cat 5 strength for a short time? I know this is a ridiculous question given how early it is...but its been a long time since theres been a cat 5 out in the atlantic.

Without a doubt, Cape Verde hurricanes tend to be the most strong, this one has a unusual acceleration and strength with nothing much out there to degrade it.

[SouthFLTropics]

18Z GFS should be ramping up here shortly..

Hey Aric where is that nifty site that you have that loops that NHC forecast cones

I think this is what you're looking for...

http://www.nhc.noaa.gov/archive/2011/gr ... p_5W.shtml