Hurricane Katia

[wxmeddler]

I agree 100% on TD 11 in the next 36 hours. Abosolutly favorable conditions. Not alot of dry air working in.NAM models are favorable as well as the EURO and GFS for the development in 36hrs.Most of all the wave is impressive.

Hate to bring down your blimp on your first post here but um... This system isn't even in the NAM's grid area, so how can you tell the NAM shows conditions favorable for development?

[dan88]

1. SHOWERS AND THUNDERSTORMS HAVE CONTINUED TO BECOME BETTER ORGANIZED

THIS EVENING IN ASSOCIATION WITH A LOW PRESSURE SYSTEM LOCATED

ABOUT 400 MILES SOUTH OF THE SOUTHERN CAPE VERDE ISLANDS.

ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR FURTHER DEVELOPMENT

OF THIS LARGE DISTURBANCE...AND A TROPICAL DEPRESSION COULD FORM

DURING THE NEXT DAY OR SO AS IT MOVES WESTWARD AT 10 T0 15 MPH.

THIS SYSTEM HAS A HIGH CHANCE...NEAR 100 PERCENT...OF BECOMING A

TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

[andyhb]

Excellent looking on the TPW.

[gil888]

The only good thing about TD 10 is that the deep southerly winds cut off any junky African air at all, plus warmed the heck out of the SSTs ahead of AL92. Maybe a MH east of the islands? Upper winds sure are good for a few days at least.

[Typhoon Tip]

Read somewhere today (forgot where), that former NHC Director Max Mayfield says this could be a legitimate threat to the East Coast in ten days.

I would be interested in his reasoning.

I tend to agree that this should be a substantial system to monitor. I couldn't comment on a 10 day threat - he may be entirely correct.

There are some products out there, some more experimental than others, that attempt to address Basin potentials, and all of them that I have seen are on the N side of the probability curve so to speak, particular from the middle CV track region and up off the EC.

[AppsRunner]

This is what he posted on facebook:

Henry Margusity Fan ClubWhat bothers me about the next hurricane, the Euro model shows it right next to NYC on 9/11 which would be a terrible terrible thing to happen.

Henry Margusity Fan Club We have the Euro model out past 300 hours in the pro site

That's not the Operational, that's the monthly control, which goes out to 360 hours. Either way, why even mention that? Hope he doesn't do that this winter.

Just for the record ..accuweather pro does have the ECM beyond 240 hours out. Matter of fact they have it monthly as well. They have all the MSLP maps etc showing where systems track etc. I believe he was just saying what the ECM was showing and that it would be a very bad thing to happen if it were to occur.

Well I could do that for free...

Anyways up to 100% probability, should be a TD within 36 hours. Still is fighting off a bit of shear with the best convergence well South East of the system, but other than that, not much is stopping this from developing.

[Typhoon Tip]

Deep convection erupting tonight -

[RobbTC]

Read somewhere today (forgot where), that former NHC Director Max Mayfield says this could be a legitimate threat to the East Coast in ten days.

http://www.duluthnewstribune.com/event/apArticle/id/D9PDEGLO2/

As the East Coast cleans up, it can't afford to get too comfortable. Off the coast of Africa is a batch of clouds that computer models say will probably threaten the East Coast 10 days from now, Mayfield said. The hurricane center gave it a 40 percent chance of becoming a named storm over the next two days.

"Folks on the East Coast are going to get very nervous again," Mayfield said.

[snowNH]

How does the pattern look down the road for this one?

[k***]

How does the pattern look down the road for this one?

unfortunately no one has discussed this in this thread

[Eyewall2005]

How does the pattern look down the road for this one?

As of now with this thing developing sooner rather then later the odds favor a recurve well east of the U.S. also the ridge to its north is alot weaker this time around then with irene.

[Amped]

How does the pattern look down the road for this one?

Nice troff but it's to far east and the flow is progressive. Irene foold me when the western ridge temporarily retrograded and Presto the crappy pattern was suddenly a good pattern.

[Hurriplane]

I thought there was post back in this thread that showed the ridge building back up to the north..

[phil882]

Some of my thoughts on Invest 92L... I'm not going to speculate beyond the next 24-48 hours, but we should see this become our next tropical system.

http://philstropicalweatherblog.wordpress.com/2011/08/28/irene-weakens-to-a-tropical-storm-as-it-undergoes-extra-tropical-transition-tropical-storm-jose-is-born-invest-92l-on-its-way-to-tropical-cyclone-status/

[wxmx]

It will be a tease, it looks like, but has a chance of being a bit more than that... Right now I'd say north of the islands and a recurve between the CONUS and Bermuda...

[k***]

This should rack up some nice ACE for us.

[wxmx]

This should rack up some nice ACE for us.

It looks like a major in 3-4 days....should rake some good ACE points...my WAG is 45-50.

[Stebo]

TD 12 is born

TROPICAL DEPRESSION TWELVE DISCUSSION NUMBER 1

NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011

500 AM AST MON AUG 29 2011

THE AREA OF LOW PRESSURE IN THE FAR EASTERN ATLANTIC TO THE SOUTH OF

THE CAPE VERDE ISLANDS HAS GAINED SUFFICIENT CONVECTIVE

ORGANIZATION TO BE CLASSIFIED AS A TROPICAL DEPRESSION. A CURVED

CONVECTIVE BAND WRAPS AROUND THE WESTERN AND SOUTHERN SIDE OF THE

SYSTEM AND THE INITIAL INTENSITY IS SET TO 30 KT BASED ON THE 06Z

DVORAK CLASSIFICATION FROM TAFB. THE DEPRESSION IS CURRENTLY IN AN

EASTERLY SHEAR ENVIRONMENT SITUATED TO THE SOUTH OF AN UPPER-LEVEL

RIDGE OVER THE EASTERN ATLANTIC. SOME EASTERLY SHEAR IS EXPECTED TO

PERSIST...BUT OTHERWISE THE ENVIRONMENT SHOULD BE CONDUCIVE FOR

STRENGTHENING THROUGH THE PERIOD. THE OFFICIAL INTENSITY FORECAST

SHOWS SLOW STRENGTHENING IN GOOD AGREEMENT WITH THE SHIPS...GFDL...

AND HWRF MODELS THROUGH 48 HOURS. AFTER THAT TIME THE CYCLONE SHOULD

STRENGTHEN A LITTLE MORE QUICKLY AS IT MOVES OVER PROGRESSIVELY

HIGHER OCEAN HEAT CONTENT. AT DAYS 3 THROUGH 5 THE NHC FORECAST IS

CLOSEST TO BUT A LITTLE BELOW THE HWRF MODEL. THE SHIPS FORECAST

LATE IN THE PERIOD APPEARS TOO LOW DUE TO STRONG SOUTHERLY SHEAR

IMPARTED BY THE TROPICAL CYCLONE VORTEX IN THE GFS MODEL FIELDS...

WHICH IS DISPLACED TO THE SOUTH AND EAST OF THE OFFICIAL TRACK.

THE INITIAL MOTION ESTIMATE IS TOWARD THE WEST OR 270 DEGREES AT 13

KNOTS. THE DEPRESSION IS CURRENTLY SITUATED TO THE SOUTH OF THE

SUBTROPICAL RIDGE...BUT THE WESTERN EDGE OF THE RIDGE WILL WEAKEN

OVER THE NEXT DAY OR TWO AS A MID/UPPER-LEVEL LOW CUTS OFF AND

RETROGRADES ACROSS THE CENTRAL ATLANTIC. THIS WILL ALLOW THE

DEPRESSION TO TURN TOWARD THE WEST-NORTHWEST DURING THE NEXT DAY OR

SO. AFTER 48 HOURS...THE MID/UPPER-LEVEL-LOW WEAKENS AND THE RIDGE

RE-STRENGTHENS TO THE NORTHEAST OF THE CYCLONE...WHICH SHOULD

RESULT IN A CONTINUED WEST-NORTHWESTWARD MOTION THROUGH THE END OF

THE PERIOD. THE OFFICIAL NHC TRACK FORECAST IS SOUTH OF AND FASTER

THAN MOST OF THE GUIDANCE FOR THE FIRST 48 HOURS...AS MOST OF THE

DYNAMICAL MODELS SHOW A MORE POLEWARD AND SLOWER MOTION THAN IS

CURRENTLY OBSERVED. DURING THIS TIME THE NHC TRACK IS BETWEEN THE

DYNAMICAL MODEL CONSENSUS AND THE LBAR...WHICH TYPICALLY PERFORMS

WELL IN THE DEEP TROPICS. AT 72 HOURS AND BEYOND THE NHC FORECAST

IS CLOSE TO A BLEND OF THE HWRF...GFDL...AND ECMWF MODELS AND IS

MUCH FASTER THAN THE LATEST RUN OF THE GFS.

FORECAST POSITIONS AND MAX WINDS

INIT 29/0900Z 9.4N 26.3W 30 KT 35 MPH

12H 29/1800Z 9.8N 28.3W 35 KT 40 MPH

24H 30/0600Z 10.7N 30.9W 40 KT 45 MPH

36H 30/1800Z 11.9N 33.5W 45 KT 50 MPH

48H 31/0600Z 13.1N 36.3W 50 KT 60 MPH

72H 01/0600Z 15.0N 42.5W 65 KT 75 MPH

96H 02/0600Z 16.5N 48.0W 75 KT 85 MPH

120H 03/0600Z 18.0N 52.0W 85 KT 100 MPH

$$

FORECASTER BRENNAN

[Srain]

06Z

[GaWx]

I'm going 90% chance of recurve east of the US based on combo of longterm climo, which says that about 83% of any storms that first become a TD east of 50W miss the continental US, and the strong model consensus for a recurve/virtually no Bermuda high, which is in total contrast to what the GFS started showing on 8/15 for Irene. (Also, keep in mind that the model consensus was too far west when it first showed US hits.) Whereas the lower latitude argues for a lower chance for recurve vs. if it were higher, the far east formation along with forecast for rather quick development argue for high chance for recurve. If this were to stay weaker than forecast and/or if it were to move WSW while in the E ATL, I could see that 10% chance of no recurve increasing a good bit.

[Ed Lizard]

Day 10 Euro and GFS both absolutely scream fish. But it should be a beautiful satellite presentation fish, and if you can't get a storm that follows Irene's track but with 40 knots more wind, the next best thing is seriously hot satellite pawn.

[IsentropicLift]

The 00z GFS ensembles had a whole variety of possible outcomes, several of which included hits.

[MarkSC]

I'm not at all convinced of fish. The models have this moving WNW now when it is actually moving W. Also, it is undergoing strong easterly sheer, which should prevent it from strengthening in the short term so should allow a more W movement. Finally, the CMC brings it to the east coast, and the Euro has been pretty inconsistent with the long range trough position and the strength and position of a cutoff low that will affect Katia's path. Yes, it is more likely than not to fish, as all CV storms are, but I still say it is less likely than the average CV storm.

[wxsmwhrms]

I agree with those that say right now the models favor a fish, which is the obvious most likely solution. But I will say that as one would expect, the models are waffling tremendously with the strength and location of the troughing out at Day 10. The 00Z EC looks nothing like yesterday's 12Z. So there's still a lot of time to watch this, and of course to see how it develops and moves in the shorter term. Just looking at climo on systems developing at this low a latitude and this far east, a good benchmark seems to be 25N, 60W. Since 1950, 16 systems in August/September that started within 300 nm of where NHC has the TD this morning went on to become major hurricanes. Of the 7 that went SW of 25N 60W, 5 hit the CONUS, 1 hit Nova Scotia, and 1 hit Newfoundland. All of the 9 that went NE of 25N 60W were fish. (Of course, this assumes that this TD goes on to become a major as the models seem to imply.)

[IsentropicLift]

The 06z GEFS ensemble looks like Earl, its just one run, but it makes the case that this could be a close call

[IsentropicLift]

And interestingly enough, if you fast forward 48 hours, there is a strong case for an "Irene" type threat. It appears that a slower paced models favor a track towards the SE coast

[Floydbuster]

Odd that once it becomes a hurricane, and if it becomes a major one, the season will be 12/2/2. Jeez...

[am19psu]

And interestingly enough, if you fast forward 48 hours, there is a strong case for an "Irene" type threat. It appears that a slower paced models favor a track towards the SE coast

I wouldn't recommend using the GFS ensembles for any tropical cyclone forecasts. It uses the "old" GFS radiation scheme and has poor resolution. It'll be better next year after the FY12 upgrades get implemented. If you have access to the Euro ensemble, it is a much better MR forecast tool for TCs.

[Juliancolton]

Hurricane Irene --> TD 10 --> Tropical Storm Jose --> "K" storm. Sound familiar?

Simple observation, not comparing Katia to Katrina by any means, etc...

[IsentropicLift]

I really wish you'd go back to the NYC forum and would stop posting 300 hr GFS ensembles.

I really wish you would stay out of the NYC subforum, nevertheless, I was simply stating that the GEFS ensembles appear to favor lower pressures near the SE coast around the 10-14 day range. I'm not taking it too seriously, just attempting to make a case as to why this might not be a fish, even though the odds are for a fish.