Unusual Chantal Disorganized, but has 65 mph Winds

By: Dr. Jeff Masters , 8:06 PM GMT on July 09, 2013

Share this Blog
72
+

Unusual Tropical Storm Chantal has strengthened a bit more as it speeds west-northwestwards at 26 mph away from the the Lesser Antilles Islands. Sustained winds of 38 mph, gusting to 52 mph, were observed at Martinique at 10 am AST as the storm passed. However, an automated weather station at the airport measured sustained winds of 60 mph, gusting to 78 mph, according to an official with Meteo-France. The Associated Press reported that Chantal ripped the roofs off of several homes on neighboring Dominica. An Air Force hurricane hunter aircraft measured top winds at their 1,000' flight level of 89 mph at 12:55 pm AST. Top winds seen by the aircraft's SFMR instrument were about 65 mph, in a small area east of Chantal's center. The Hurricane Hunters have departed Chantal, and the next plane is due in the storm at 8 pm EDT. Chantal's winds are unusually high considering the storm's high central pressure of 1006 mb and disorganized appearance on satellite imagery. Chantal is fighting dry air associated with the Saharan Air Layer (SAL), as seen on water vapor satellite loops. This dry air is creating strong thunderstorm downdrafts that are robbing Chantal of moisture and energy. Visible satellite loops show the outflow boundaries of these thunderstorm downdrafts at the surface, spreading to the northwest of Chantal. Martinique Radar shows a large area of heavy rain that is not well-organized, lying mostly to the west of the Lesser Antilles Islands.


Figure 1. MODIS image of Chantal taken at approximately 1 pm EDT Tuesday, July 9, 2013. At the time, Chantal had top winds of 65 mph, but looked very disorganized, due to high wind shear and dry air. Dry air is creating strong thunderstorm downdrafts that are robbing Chantal of moisture and energy. Outflow boundaries from these downdrafts are spreading out to the northwest of Chantal, as seen on this satellite image. Image credit: NASA.

An small-scale easterly jet creating high shear in Chantal
Chantal is not very impressive on satellite images, with a modest amount of heavy thunderstorms that are not well-organized. Only a small amount of upper-level outflow is visible. The reason for Chantal's rather disorganized appearance can be found by looking at this morning's balloon sounding from Guadaloupe. This island was just northwest of the center of Chantal when the balloon was launched at 8 am EDT. The sounding showed typical easterly trade winds at the surface of 12 knots (14 mph.) However, the winds rose quickly aloft, with a jet of easterly winds of 35 - 53 knots between 800 - 600 mb (about 7,000 - 15,000'.) But, by the time the ballon hit 500 mb (18,000'), the winds had died down to 15 knots. A change of wind speed from 12 knots to 53 knots and back down to 15 knots from the surface to 500 mb is a tremendous amount of wind shear, which will make it very difficult for a tropical storm to keep the surface center aligned with the upper level center. The traditional measure of wind shear, the difference in wind between 200 mb and 850 mb, was 44 knots in this morning's Guadaloupe sounding, but was a much higher 56 knots from 200 mb to 700 mb. The powerful easterly wind jet was not apparent at any of the other balloon soundings this morning at adjacent islands (Barbados, Puerto Rico, Saint Martin), and demonstrates that there is a lot going on the atmosphere at small scales we cannot see which makes intensity forecasting of tropical cyclones very challenging. Thanks go to Jason Dunion of NOAA's Hurricane Research Division for pointing out this morning's interesting Guadaloupe sounding.

Forecast for Chantal
Chantal will have difficulty intensifying much more before hitting Hispaniola on Wednesday afternoon. In their 11 am EDT wind probability forecast, NHC gave Chantal a 29% chance of becoming a hurricane before hitting Hispaniola. Working against intensification will be the high wind shear from the strong mid-level easterly jet discussed above, plus the fast forward speed of the storm--tropical storms moving faster than 20 mph in the deep tropics usually have trouble intensifying. In addition, the Eastern Caribbean is an area where the trade winds accelerate, helping drive sinking air that discourages tropical storm intensification. Dry air will also slow down the intensification process. Interaction with the high mountains of Hispaniola and high wind shear may be able to destroy Chantal by Thursday. The 2 pm EDT Tuesday wind shear forecast from the SHIPS model calls for shear to rise to the high range, 20 - 35 knots, Tuesday night through Friday. On Saturday, when Chantal is expected to be in the Bahamas, moderate wind shear of 10 - 20 knots is predicted. If Chantal survives until Saturday, it will then have the opportunity to re-strengthen. The latest 12Z run of the European model (ECMWF) dissipates Chantal as it crosses Hispaniola. The 12Z run of the American GFS model has Chantal barely surviving.

Chantal's fast west-northwest forward speed of 26 mph will slow to 20 mph by Wednesday morning and then 10 mph by Thursday night, as the storm "feels" the presence of a trough of low pressure over the U.S. East Coast. This trough will steer Chantal to the northwest and then north-northwest across Hispaniola and into the Bahamas. The trough of low pressure pulling Chantal northwards is expected to lift out the the northeast over the weekend, leaving Chantal behind off the coast of Florida. High pressure will likely build in, potentially forcing Chantal westwards into the Florida or Southeast U.S. coast, with a possible Sunday landfall.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 336 - 286

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54Blog Index

I think Chantal could become a hurricane before hitting the hispaniola area. Between there & Cuba, not sure she will stay intact, however. Yet, depending on where reemergence is could determine if/when any reorganization takes place. -- If she somehow does the unimaginable & stays low or squeaks between hispaniola & Cuba with light damage to her winds, it could be another game altogether -- ...IF.
Member Since: Posts: Comments:
911 Operator ‏@911BUFF 2m
BREAKING NEWS - NATURAL GAS FLOWING INTO THE GULF OF MEXICO NEAR LOUISIANA. 4 BY 3 MILES WIDE SHEEN REPORTED. USCG RESPONDING & EVACUATING.
Member Since: Posts: Comments:
Quoting 325. Jedkins01:


They do so because models can suddenly shift back in the other direction.

I will say one thing, I won't be surprised if the models continue to shift left with time, as there hasn't been a single tropical wave or tropical low that has passed east of Florida. The trend for the Bermuda high has been to block the Atlantic Ocean.

However, really it could go either way, because east coast troughs have been quite robust for a long time now, so we'll see.


I would do the same thing, My comment was not a complaint, just an observation in their behavior.
Member Since: March 10, 2006 Posts: 0 Comments: 10242
Quoting 303. MiamiHurricanes09:
Stacy Stewart on the other hand is a pretty scary sounding dude. :P

https://www.youtube.com/watch?v=SnPcd1_EY1g
Do you have Robbie Berg?
Member Since: Posts: Comments:
Quoting 325. Jedkins01:


They do so because models can suddenly shift back in the other direction.

I will say one thing, I won't be surprised if the models continue to shift left with time, as there hasn't been a single tropical wave or tropical low that has passed east of Florida. The trend for the Bermuda high has been to block the Atlantic Ocean.

However, really it could go either way, because east coast troughs have been quite robust for a long time now, so we'll see.


True on all points. IF this survives, best chances of landfall are from ECFL up to GA/SC border. I simply do not see this skirting S into the Gulf.
Member Since: Posts: Comments:
Are those arc clouds? I don't recall a tropical storm with outflowing arc clouds before. Maybe they're not arc clouds but they look like them.

Jedkins there's a comment on my blog that mentions you ;) Levi's in there too.
Member Since: Posts: Comments:
Quoting 307. VirginIslandsVisitor:


Good afternoon, evening everyone

Well, the breezes are getting stronger and the clouds are darkening up.

Regarding the anticipated tide surge, the smaller fishing boats have been pulled up out of the water. None of the larger boats have been pulled but I saw a few of the fishermen looking a little worried about half an hour ago.

The cruise ship, Carnival Liberty, never came in this morning so must have been diverted to better weather.

Lindy







If you're BVI you should be fine from this one. Unless something changes, of course. Keep an ear to your local officials.
Member Since: Posts: Comments:
329. whitewabit (Mod)
Quoting 325. Jedkins01:


They do so because models can suddenly shift back in the other direction.

I will say one thing, I won't be surprised if the models continue to shift left with time, as there hasn't been a single tropical wave or tropical low that has passed east of Florida. The trend for the Bermuda high has been to block the Atlantic Ocean.

However, really it could go either way, because east coast troughs have been quite robust for a long time now, so we'll see.


Models always seem to have trouble with weak storms ..
Member Since: Posts: Comments:
Quoting 309. Dakster:


I disagree. I am certain they do not know where Chantal will go.



the strength could range from a tropical wave to a cat 2 hurricane at it's final landfall
Member Since: Posts: Comments:
Quoting 317. BaltimoreBrian:


Surviving being a boy named Stacy would make you tough!
Lmaoo, very true.
Member Since: Posts: Comments:
Quoting 311. GTstormChaserCaleb:
No wonder the Eastern Caribbean is called the "Dead Zone" convection starting to wane.



The John Hope rule.
Member Since: Posts: Comments:
Quoting 175. Dakster:
Umm. The NHC may not buy the model shift just yet. They seem to move slowly and with an abundance of caution.


They do so because models can suddenly shift back in the other direction.

I will say one thing, I won't be surprised if the models continue to shift left with time, as there hasn't been a single tropical wave or tropical low that has passed east of Florida. The trend for the Bermuda high has been to block the Atlantic Ocean.

However, really it could go either way, because east coast troughs have been quite robust for a long time now, so we'll see.

Either way, Chantal is not a very impressive system, and even if it does impact Florida or elsewhere in the southeast, I don't think it will be much of a threat. Currently satellite suggests it could even open into a wave, not that it is, but that it could.
Member Since: Posts: Comments:
This:

Member Since: Posts: Comments:
Quoting 282. GTstormChaserCaleb:
Here Washi, Dr. Lixion Avila image


Man that Avila is something else. I personally prefer Stewart though
Member Since: Posts: Comments:
Looking at this bouy it would be difficult to determine a TS is approaching.


Member Since: Posts: Comments:
Quoting 315. interstatelover7166:
Levi, if I may ask, what is "col"?


Cut Off Low.
Member Since: Posts: Comments:
Quoting 312. RitaEvac:
Day 4 and 5 cone is not legit, if anything it's on the wrong dang side of Florida


Sure could be. I am afraid that this could be another Katrina in the making. Only this time with an oil blow out in the Gulf. This could spell certain doom. ;/

O_o
Member Since: March 10, 2006 Posts: 0 Comments: 10242
Quoting 302. Hurricanes305:


Exactly those models are over rating the trough as theyy usually do doubt that this High will let this storm go that far north. Without any tug west.
I won't rule out a track up the spine of the state like Fay or even up the West Coast of FL.
Member Since: Posts: Comments:
Quoting 311. GTstormChaserCaleb:
No wonder the Eastern Caribbean is called the "Dead Zone" convection starting to wane.



Has more to do with tradewinds killing the coc
Member Since: Posts: Comments:
Quoting 303. MiamiHurricanes09:
Stacy Stewart on the other hand is a pretty scary sounding dude. :P

https://www.youtube.com/watch?v=SnPcd1_EY1g


Surviving being a boy named Stacy would make you tough!
Member Since: Posts: Comments:
Mail Chuck.
Member Since: Posts: Comments:
Quoting 295. Levi32:


That would entirely depend on time over water, which right now is a big question. If the models are correct in shifting the track west, water time may be much reduced, resulting in a weak TS. If the runs from last night giving Chantal 48 hours over the gulf stream underneath a 200mb col came to pass, a hurricane wouldn't be out of the question.

It's honestly one of the most difficult things to forecast intensity for a storm post-Hispaniola. Too many things can happen near Hispaniola and Cuba. Speculating before her crossing is fraught with uncertainty.
Levi, if I may ask, what is "col"?
Member Since: Posts: Comments:
ZOOM here to see the ULL in the Fla Straits, click "fronts" to see the trough now.

Gulf Of Mexico - Visible Loop

click image to run LOOP



Member Since: Posts: Comments:
Hi Everyone, The way this storm has been acting, I wouldn't be a bit surprise if it did what ever it wanted to.
Member Since: Posts: Comments:
Day 4 and 5 cone is not legit, if anything it's on the wrong dang side of Florida
Member Since: Posts: Comments:
No wonder the Eastern Caribbean is called the "Dead Zone" convection starting to wane.

Member Since: Posts: Comments:
Quoting 292. BaltimoreBrian:
Chucktown what do you think about Chantal's prospects after Hispaniola? Seems like she's heading your way.


Not too concerned at the moment. We can handle a 45-50 mph TS if the current track holds, but today is Tuesday, the NHC track ends Sunday. Still lots of uncertainties in between. I'd be a little more concerned if this was September and Chantal was just off the SE US coast. Probably going to be a pretty good easterly pinched gradient between the high trying to build in and Chantal. Anyway you slice it, very windy from Miami to Wilmington along with strong rip currents and some beach erosion likely.
Member Since: Posts: Comments:
Quoting 305. AllStar17:
The forecast for Chantal in the long range remains uncertain to say the least.


I disagree. I am certain they do not know where Chantal will go.
Member Since: March 10, 2006 Posts: 0 Comments: 10242
TWC Jim Cantore said if this storm bends back west towards Georgia and South Carolina no matter how weak or strong it is, as wet as it has already been.....a disaster in the making if it turns out that way
Member Since: Posts: Comments:
Quoting 165. PRweathercenter:



i just a wind gust of 39 mph in south east puerto rico, no rain, very breezy!


Good afternoon, evening everyone

Well, the breezes are getting stronger and the clouds are darkening up.

Regarding the anticipated tide surge, the smaller fishing boats have been pulled up out of the water. None of the larger boats have been pulled but I saw a few of the fishermen looking a little worried about half an hour ago.

The cruise ship, Carnival Liberty, never came in this morning so must have been diverted to better weather.

Lindy





Member Since: Posts: Comments:
Quoting 298. georgia325:

Excellent:( possible double whammy.


It would be one or the other, probably georgia
Member Since: Posts: Comments:
The forecast for Chantal in the long range remains uncertain to say the least.
Member Since: Posts: Comments:
Some computer models are forecasting 2 more cape-verde storms to follow after Chantal.

Looks like this year will be VERY active.

I still don't want to believe we could have up to 20 storms in the Atlantic again. However, it looks like that is becoming more and more probable.

Do you guys have any season forecasts?

I am guessing 18 - 24
Member Since: Posts: Comments:
Stacy Stewart on the other hand is a pretty scary sounding dude. :P

https://www.youtube.com/watch?v=SnPcd1_EY1g
Member Since: Posts: Comments:
Quoting 235. GTstormChaserCaleb:
Looks like the NHC is expecting another westward shift in the models.


Exactly those models are over rating the trough as theyy usually do doubt that this High will let this storm go that far north. Without any tug west.
Member Since: Posts: Comments:
Quoting 270. CaicosRetiredSailor:
Results for Provo, TCI (21.78N, 72.27W):

The approximate Closest Point of Approach (CPA) is located near 20.9N, 73.2W or about 84.3 miles (135.6 km) from your location. The estimated time of when the center of the storm will be at that location is in about 1 day, 15 hours and 40 minutes from now (Thursday, July 11 at 8:42AM AST).

the little shift west in the forecast pleases me


And the old saying still applies, you make one person happy and another sad. I'm not pleased to see the shift west especially if this track continues. I really don't want the system to hit DR or Haiti; but if it doesn't hit the mountains then the projection of 70 mph and dissipating to 40 mph won't happen either. Still a lot of time and distance to cover, projections will be updated again.
Member Since: Posts: Comments:
We have more to worry about the one that is behind her than we do of Chantal.



Link WV Loop EATL
Member Since: Posts: Comments:
For those that missed my newest blog post from last Masters' blog post, here's the link:

Bluestorm5's Blog on Chantal 7/9/13 15:00 EST
Member Since: Posts: Comments:
Quoting 285. BaltimoreBrian:


Chantal may come to Georgia on Sunday/Monday. You'll be just in time!

Excellent:( possible double whammy.
Member Since: Posts: Comments:
Interesting to note what NHC says about the forecast cone
"THE GUIDANCE ENVELOPE SHIFTED WESTWARD IN THE LAST
RUN AND CONSEQUENTLY...THE OFFICIAL FORECAST WAS ADJUSTED IN THAT
DIRECTION
...BUT NOT AS FAR AS THE MODEL CONSENSUS. IF THIS WESTWARD
MODEL TREND CONTINUES IN THE NEXT CYCLE...I WILL NOT BE SURPRISED
IF ANOTHER WESTWARD SHIFT WILL BE REQUIRED."
Member Since: June 13, 2009 Posts: 2 Comments: 11940
I am having my doubts that Chantal survives the mountains. It's a wait and see game.
Member Since: Posts: Comments:
Quoting 268. BaltimoreBrian:


Assuming option 2, about how strong do you think Chantal would get?


That would entirely depend on time over water, which right now is a big question. If the models are correct in shifting the track west, water time may be much reduced, resulting in a weak TS. If the runs from last night giving Chantal 48 hours over the gulf stream underneath a 200mb col came to pass, a hurricane wouldn't be out of the question.

It's honestly one of the most difficult things to forecast intensity for a storm post-Hispaniola. Too many things can happen near Hispaniola and Cuba. Speculating before her crossing is fraught with uncertainty.
Member Since: November 24, 2005 Posts: 635 Comments: 26646
NHC HH Flight TEAL 71 goes wheels up @ 7:00PM CDT
Member Since: Posts: Comments:
Quoting 274. BaltimoreBrian:
However, Chantal is so small and has such a high central pressure that I think it is more likely than not that Hispaniola kills her.

Chantal will then become a remnant of her former self somewhere off the east coast of Florida.
...no one is quite sure where...
fitting end for a CV storm in the 2nd week of July!
Member Since: Posts: Comments:
Chucktown what do you think about Chantal's prospects after Hispaniola? Seems like she's heading your way.

Barbamz please check out my blog for articles list.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting 269. Dakster:
He's not young. Here is his bio. Received a degree in 1973. A very decorated forecaster too.

http://www.nhc.noaa.gov/staff/avila_2012.pdf

Link



LOL, nice link, I still think Max is the GOAT
Member Since: Posts: Comments:
Hi everybody. I see not much change in the 5:00 advisory intensity wise...still lots of questions left to be answered
Member Since: Posts: Comments:
Quoting 251. WhereIsTheStorm:


Great looking storm, lousy path. I'm assuming the people in this area are ready for what's coming.


Agreed. The sad thing is that each forecast update since it first started has increased its future strength. The last update expected it to weaken significantly down to a cat 2 storm before hitting land. Now it is forecast to hit land as a cat 3 storm. I have a feeling it may reach a cat 5 peak sometime tomorrow and hit land as a lower end cat 4 instead. Hopefully I'm wrong though and I hope people are prepared!
Member Since: Posts: Comments:
Quoting 249. washingtonian115:
What does Alivia look like?
Don't know if you speak Spanish, but here's one of the videos he's featured in during this years hurricane preparation week.

https://www.youtube.com/watch?v=jjcjEsi5tgI
Member Since: Posts: Comments:
Quoting 265. nrtiwlnvragn:


Link


Thanks, really nice. Quote from that interview (especially for WU, lol):

We've had an infusion of new blood in the hurricane specialist unit during the past few years. Do you see in them a little bit of what you went through?

Avila: Oh yes. Some of them are really excited just like me. They think they know how to forecast and come in very "pompous". But everyone will learn, or have already learned, that it's not that simple. When I finished fresh from school, I thought I was going to solve all of the problems, be able to predict intensity, be able to do everything. But as soon as you put your name on that forecast, you become very humble. And that's good. I am glad people are coming with a lot of enthusiasm, and they bring new ideas and new techniques.
Member Since: Posts: Comments:

Viewing: 336 - 286

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
67 °F
Overcast