ATL: ISAAC - Post-Tropical - Discussion

[northjaxpro]

Good morning everyone,

Well, our system has generated a nice ball of convection near the center of circulation and now we have liftoff of TD #9. Folks, get plenty of coffee out of the cabinet as we will have many long days and nights tracking this large and potentially very formidable tropical cyclone. I just looked over the latest information from NHC, and my goodness they are really expecting TD 9 to intensify into a potent Cat 2 tropical cyclone on a track which will take the center just south of Hispaniola and making the turn midway between Jamaica and Hispaniola. This track would indeed favor intensification and it is certainly very possible. Now, this track certainly may change and again, the precise track will make all the difference you can imagine with this cyclone.

Keep in mind, this is a very large system and it has such an expansive circulation that even if land interaction with Hispaniola and Cuba occurs, its size will help the system in recovering. It will be where the inner core tracks. The inner core certainly would get disrupted if it entangles with the high terrain of Hispaniola and Eastern Cuba, but the large moisture envelope this system possesses would help this system to re-organize should this scenario occur. But, if the track of the center south of Hispaniola verifies, we may be looking at a system which will be very eerily similar in a projected track to that of Hurricane Cleo in 1964. Check out the analog of Cleo.

So, the talk about the dreaded history of "I" storms certainly will reach a fever pitch in the days to come. Unfortunately, if the dynamical models are correct and the envionmental conditions stay conducive which is forecast, we have potential major problems coming for the Caribbean and by the weekend, the Florida peninsula and the Bahamas as a digging shortwave over the Southeast U.S. this weekend will pull the cyclone poleward. In the next few days, my thoughts and prayers to all our friends and neighbors in the Caribbean as this developing cyclone barrels through that region.

I am sure they are putting their preparations into action. Then, by Friday and into the weekend, everyone from the extreme Eastern GOM, the entire Florida peninsula, the Bahamas and the Southeast U.S. will really have to be vigilant. The odds are unfortunately becoming increasingly probable that this soon to be named "Issac" will be impacting these areas late this weekend. ________________________________

My posts in this forum are NOT official forecast. They are just the opinion of this poster. For official information, please refer to the NHC and NWS products

[KWT]

Cleo's track certainly is a good looking analog for the first part of the track, I don't think TD9 will curve up so sharply through Cuba, I think it'll be a touch further west and a more gentle curve up through say central Cuba, just into the Gulf.

Frankly this is a tough call however, such small differences in track will lead to a massive change in strength down the line.

[Blown Away]

If TD9 goes skirts or goes just north of Hispaniola it could be scary. JMHO only!

[Gustywind]

21/0545 UTC 15.1N 50.3W T1.5/1.5 94L
20/2345 UTC 15.2N 48.7W T1.0/1.0 94L

[Cyclenall]

Wow, the NHC is being very bullish on TD9. It is one of the most aggressive intensity forecasts in a very long time for the Atlantic, rare to get up to 95 knots by the 4th day which means if there was no land interaction, the day 5 point would be over major status. This was unexpected because not even the latest Euro run shows that type of strengthening for the next 120 hours but I think they were influenced by that run.

Comparing first advisories and dates, Hurricane Irene of last year formed one day before Nine did and did not have this high of an intensity prediction. Hurricane Ernesto of 2006 formed 3 days after today and also did not even come close to initiation strength forecasts (60 knots instead of 95 knots). The upper level regime must become pretty darn amazing here coupled with the highest heat content in the basin.

[KWT]

IMO cyclenall its actually too agressive, but the convection at the moment is pretty impressive and it does look good.

Somwhere is going to get walloped, at the moment I think Haiti may well get a big hit even if it does manage to remain offshore.

[Gustywind]

Tropical Depression #9 Forms To The East Of The Lesser Antilles; Tropical Storm Watches & Warnings Issued For Puerto Rico, The Virgin Islands & The Leeward Islands
Tuesday, August 21, 2012 5:26 am

by Rob Lightbown
http://www.crownweather.com/?page_id=4557
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

Tropical Depression #9:
Invest 94L fired enough deep convection during the overnight hours to be considered a tropical depression, therefore, the National Hurricane Center has upgraded Invest 94L to Tropical Depression #9. TD 9 seems to be tracking a little south of due west at a forward speed of 18 to 19 mph. This system is currently located to the south of a west-southwest to east-northeast oriented high pressure system and this should keep TD 9 on a general westward track for the rest of this week. This track will bring TD 9 directly over the island of Dominica on Wednesday afternoon as a 50 to 60 mph tropical storm.

Once in the Caribbean, the track of TD 9/Isaac will be influenced by that high pressure ridge. Most of the forecast guidance show a track across the northern Caribbean, however, I think this may be too far of a north track, especially considering the depression’s current slightly south of due west track. Even the latest GFS model, which takes this system across central Cuba and then rakes all of Florida’s east coast before landfalling in eastern Georgia, seems a little too far north.

So, I’m leaning closer to the European model guidance track which takes TD 9/Isaac right across the islands of Guadeloupe and Dominica late Wednesday and then just south of Puerto Rico on Thursday. From there, the European model guidance forecasts that this system will miss Hispaniola and then track very close to the north coast of Jamaica on Sunday.

Beyond Sunday, the European model guidance forecasts a track that takes Isaac-to-be across western Cuba next Tuesday and then northward towards western Florida and the Florida Panhandle by next Thursday as possibly a hurricane.

So, all residents and vacationers in the Leeward Islands, Virgin Islands and Puerto Rico should prepare for tropical storm conditions. Those of you further west across Jamaica, the Cayman Islands and Cuba should closely monitor the progress of TD 9/Isaac. It is looking more and more likely that this system will be a hurricane when it tracks very close to Jamaica on Sunday.

Finally, all residents and vacationers across the Florida Peninsula and the Florida Panhandle need to keep very close tabs on the forecast track of this system. Go over your hurricane preparedness kits today and make sure you know what to do should Isaac come knocking on Florida’s door later next week.

I am monitoring Tropical Depression #9 very closely and will continue to update you on the latest.

[lilybeth]

Wow, I had out of town visitors this weekend and check this morning in to find all this activity. Very surprised to see the forecast track have it at Cat 2! It worries me for all in the possible path...but I have to say I'm especially concerned with Haiti. They are still reeling in many areas.

Can I ask a question to some of our seasoned members? IF (big IF), the storm does follow that exact path, and hit the exact intensity levels. What could our friends in Haiti experience? Anyone take a guess based on my parameters?

And I am not trying to be an alarmist. I know this is so far out and so many factors can come in to play - the storm could never even get named, the track could recurve, etc etc. But saying it does follow - how would one expect Haiti to fare? (I worry due to the fact they are still struggling after the earthquake)

Thank you for any and all responses. I respect everyone here so very much and hope this is an acceptable question (even if it is just a hypothetical one at this point).

Thanks again.

[TheBurn]

10:00 UTC RGB // Natural Color
TD9 followed closely by 96L

[Blown Away]

Map of all classified systems within 65 miles of TD#9's current position. Some heavy hitters for Florida. Note, not many affected SFL following TD#9's current projected path, they went west.

[summersquall]

First visible..


I don't wish this on anyone. Large systems are more susceptible to poleward forces which could influence the track and result in a more central path?

[Gustywind]

000
AXNT20 KNHC 210601
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE AUG 21 2012

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0515 UTC.

...SPECIAL FEATURES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 20N47W 17N49W TO
A 1009 MB LOW PRESSURE THAT IS ALONG THE WAVE NEAR 15N49W.
CONVECTIVE PRECIPITATION...SCATTERED STRONG FROM 10N TO 13N
BETWEEN 46W AND 52W ALONG THE SOUTHERN SIDE OF THE SYSTEM...
SCATTERED MODERATE TO ISOLATED STRONG ALONG THE NORTHERN SIDE
OF THE SYSTEM FROM 13N TO 18N BETWEEN 46W AND 52W. BROKEN TO
OVERCAST MULTILAYERED CLOUDS AND OTHER POSSIBLE RAINSHOWERS
COVER THE ATLANTIC OCEAN ELSEWHERE FROM 10N TO 20N BETWEEN 38W
AND 56W. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WESTWARD 20 TO
25 MPH. IT IS POSSIBLE THAT THIS LARGE DISTURBANCE MAY REACH
THE LESSER ANTILLES BY WEDNESDAY...AND RESIDENTS IN THAT AREA
SHOULD MONITOR CLOSELY THE PROGRESS OF THIS SYSTEM SINCE
TROPICAL STORM WATCHES MAY BE REQUIRED SOON FOR SOME OF
THOSE ISLANDS.

[CalmBeforeStorm]

First visible..


I don't wish this on anyone. Large systems are more susceptible to poleward forces which could influence the track and result in a more central path?

Are there really any doubts that this is already Issac?

[perk]

TD#9 appears to be tracking wsw,or is it just me.

[TheBurn]

06:45 EDT WV_Enhanced
Early season trough clearly defined and diggin' in through the SE CONUS.

[Blown Away]

JB thinks the potential is very high!

[GCANE]

Continuing to fire a few overshooting tops.

http://www.nrlmry.navy.mil/tc-bin/tc_ho ... D=1km_zoom

[tolakram]

Morning Visible

[tolakram]

Live loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... umframes=5

RBTOP Loop, convection pulsing.

[psyclone]

Well the atmospheric volcano has finally blown its top and 94l finally has some meat on its rather large frame. looks amazing in the visible pic with the outflow fanning out and overshooting tops poking through. simultaneously scary and beautiful.