The Unique Case of Chantal.... A Complex Look at a Complicated Storm.. Pluses & Minuses

Trying to understand Tropical Storm Chantal is like Trying to Reason with Hurricane Season. She is unique and she deserves a complex look at her very complicated situation.

I woke up this morning expecting to see nothing more than a cluster of clouds in the Caribbean lingering south of Haiti punching westward and a possible downgrade to Tropical Depression Status. She hasn't looked good once on satellite imagery over the last 36 hours ...and yet she is still there and being kept for now as a 45 mph Tropical Storm. Her rains and winds will impact Haiti and parts of Eastern Cuba in the short term...whether she remains a Tropical Storm or Depression or even as an Open Wave. I could be wrong, but I doubt the NHC will downgrade her to open wave without recon data. They often use satellite
imagery to determine a closed circulation but for consistency and to err on the side of caution for the other countries in the Caribbean they are often conservative in downgrading a system ...especially when the  models keep her as a viable storm with a cone that would take her over Florida. They can be stubborn at times... slow to upgrade a storm to depression status when it looks like a full fledged Tropical Storm and then as stubborn downgrading one that looks like a cluster of thunderstorms to an open wave. Every situation is different and Chantal is about as different as it gets.

Her pluses:
1) She is there against all odds and that in itself makes one worry. Historically storms that do not fall apart early on when they could have... have a tenacity to them that becomes a problem down the line. That "now you see me now you don't" doesn't play well when trying to ascertain if it is truly dead or about to blow up.
Andrew, Katrina, Betsy are all storms that played peak a boo... I might be dead...no I'm not with the forecasters until they pulled it together. Why did they pull it together? Conditions around them suddenly improved and somehow they dog paddled their way through rough water until the water calmed and then they were still there in the game and barely alive and able to compete.


Her minuses:
1) She is moving way too fast for any storm. A storm does best when it's cruising along at 15 to 18 mph. A storm going more than 20 mph is probably going too fast. A storm going close to 30 mph forward speed is acting more like a tropical derecho than a tropical storm. Good in the short term, but it can run out of steam. It hurts its ability to stack vertically in the atmosphere and maintain it's structural integrity.  Around midnight she was officially going 30 mph forward speed. Note... never once since she formed has any advisory been less than 25 mph forward speed. This factor alone is a bigger problem than the ever present shear and the ever present Saharan Dust she has encountered.

2) Shear is the big word going around and yet it is always down there and has been there for a while and shear did not kill her off and it's not the final nail in the coffin. Shear plus her fast forward speed is like that lesson in Drivers Ed when you were a kid. A car driving at 50 mph into a brick wall hits the wall with the force of ...etc, etc, etc..  A car traveling at 50 mph going straight into a large truck going 60 mph creates an impact of.. you do the math.. I'm an English major. But, you get the idea. It is a 1 - 2 punch. Why is she still there at all is the bigger question with regard to this negative. Note the shear is coming from the Pacific towards the Atlantic at this point which is in line with climo... she has also suffered shear on her NW side from the historically strong ULL to her NW now nearing Cuba.

3) Dry Air and the amount of Saharan  Dust she has carried with her since she was born just south of the SAL has been a continual monkey on her back..an African red colored dusty monkey at that. Storms born during SAL outbreaks rarely ever make it. And, yet she traveled across the Atlantic Ocean in what was basically a dry area and she sucked the tropical moisture of the ITZ along with her keeping her alive. If you look at what we playfully call the "juice loop" you will see yesterday she began to be cut off from that flow as her southern edge began to interplay with South America before she lifted a bit to the north. She was always stronger on her southern side because the strong High to her north which propelled her westward so fast was and is very dry.

Most telling loop here I can play is this one below. Note as she passes the islands her flow of moisture to the SW begins to dramatically cut off. She seems almost adrift trying to hold it together.



The following loop shows her almost exploding back to life...which is the call the doctors at the NHC will make after looking dead hours ago. Note... there is an imbalance of moisture here.. it's all on the West side of this loop...the Eastern Atlantic is dry...very dry...and that is because of the Saharan Dust that usually resides in the Eastern Atlantic at a time when storms are forming close in to land in the Gulf of Mexico and the Caribbean and the Bahamas. Chantal is really not supposed to be here yet... yet she is..



She might be "exploding now" because she is in a small area where shear is less ... and she is also getting into warmer water.



4) The 4th and final thing I will bring up here is CLIMO. Historically speaking she is bucking not just the strong shear but the historical trends. She is not supposed to really be here...Cape Verde Waves do not make it across the ocean often in early July and form in the Central Atlantic and try to plow their way into the Caribbean. Cape Verde storms do best when they go up over the islands... or pull north through the Virgin Islands and then they take their aim at the US coastline or end up recurving out to sea. Both Chantal's presence on the maps and her path is not in line with CLIMO and CLIMO almost always wins.

I remember back when I was younger and I would argue out every possibility for every tropical wave out there with mentors and colleagues who knew much more than me about CLIMO and CLIMO is another word for that other ugly word REALITY. Arguing climo is like living in denial. It doesn't end well..  Sometimes.... there are exceptions.

Bertha in 1996 was what I often call "John Hope's Blue Dot in the Middle of the Ocean" as he stood there looking confident with his big blue map with dots on it where storms usually form and the symbol for storms popped up as "Bertha" he turned slowly...looked back sort of nervously like a deer in the headlights as there was a storm where it wasn't supposed to be. A lone blue dot had just become a named storm in sea of no dots. A sweet poignant memory of a very amazing man and the reality that sometimes...rarely...climo does not win the end game. But, those times are few and far between in the same way that forecasters like John are few and far between.

http://en.wikipedia.org/wiki/1996_Atlantic_hurricane_season



So...back to Chantal.

Basically she has 4 things going against her and the only real PLUS is that she is there on the map continually blowing up "one last time" before it looks like the NHC will write her off. Making waiting for the NHC Discussion like reading a book slowly chapter by chapter waiting to see how it will end..

The models for Chantal are sort of bullish. Perhaps they predicted this blow up that is going on this morning annoying forecasters who want to write the final advisory on Chantal. Perhaps they saw that she would stay weak and by staying weak she gets further west. We can only hope and pray she does not get all the way to the Yucatan where very HOT water waits for her and the wall of shear evaporates. If so the models would have been wrong about Chantal's path up the Gulfstream, but right about her survival chances.

Models have a historically hard time trying to correlate the data with the historically incorrectness of Chantal being there at all. And, it's been an odd weather pattern with historical amounts of rain from Florida to the Carolinas which never bodes well going into the heart of the hurricane season. So, give the models a break here and let the drama play out.





Moving past Chantal is the D storm which is waiting in the wings Stage Right to be enter and read his lines.



And the MJO jumped out over the Caribbean and landed in the Central Atlantic, which we have been talking about in private chats online and was expected to happen. The MJO can be a bit fickle sometimes, it's not always a simple east, east, east movement or presence on the map. And then..it goes poof. There have been discussions on Kelvin Waves and all sorts of anomalies in various tropical basins... there are more than Tropical Waves out there.



There is a wave out in the Eastern Atlantic sitting above the MJO red and white candy cane patten sitting in the Atlantic...where Saharan Dust has ruled so far.


See the wave...see the ULL near Florida and see Chantal sending up red flares for the NHC to see she is still alive..



BOBBISTORM'S BOTTOM LINE:

There is a cone and there are watches and warnings up for Chantal. If you are in the 4 and 5 day part of the cone go about your daily business...live, love and try to be happy...and check back often on the state of Chantal and the current information the NHC and the NWS is putting out. Only time will tell if they are right or they are wrong..

As for me... trying to decide whether to stay home today or take a ride in the country for lunch somewhere or to drive down to the beach and if it's the beach...which beach...

At 11 AM there will be a new advisory...new discussion and a new cone. Keep on top of it if you live in SOUTH Florida.  I'll be back with more discussion later...when ever I get to where ever I am going sort of like Chantal.

Besos Bobbi ;)
Jimmy Buffet Links to his tropical wisdom...

Only Time Will Tell: http://www.youtube.com/watch?v=2SKIIqLc2rk
Trying to Reason with Hurricane Season: http://www.youtube.com/watch?v=Xg-zwba7l5w
Hate to admit it, but I'm old enough to remember when the NHC was at UM..and what it used to look like... and still have wall maps from Neil Frank (I was young.............) and to have watched Jimmy singing his heart out at the FLICK near UM.  He's a great singer, a wise weatherman and he has great taste in loving places like Key West..