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: 1136 - 1086

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

1136. pottery
Quoting Pallis:
I realize that we are all connected by some kind of link and all, but is there another Guadalupe Island in the Caribbean, because the one in the Pacific is pretty far away from the affected zone in your topic. There is this ostentatious piece of land called Mexico in the way. Always looking for more geographical knowledge though, if you snuck one by me, or I cheated myself out of a piece of the globe.

Guadeloupe & Martinique are 2 French islands within the Caribbean island chain.
Member Since: Posts: Comments:
No, not Dennis. Panama City needs no more rain, we're soaked.
Member Since: Posts: Comments:
1134. Walshy
Would be something if the NHC could not find a center when there is hurricane warnings out...
Member Since: Posts: Comments:
Looks kind of blobby to me
Member Since: Posts: Comments:
Watching Chantal, I feel I'm being "toyed" with...wierd, exciting, and humbling all at the same time!
Member Since: Posts: Comments:
1131. Grothar
Quoting 1115. opal92nwf:


That is the greatest little animation.
Member Since: July 17, 2009 Posts: 71 Comments: 26151
Quoting 1120. opal92nwf:
Starting to imagine this could be like a Dennis track.
I think I do remember you saying that a couple blogs ago. Doesn't seem as farfetch'd now.
Member Since: June 30, 2013 Posts: 12 Comments: 8323
1129. Pallis
I realize that we are all connected by some kind of link and all, but is there another Guadalupe Island in the Caribbean, because the one in the Pacific is pretty far away from the affected zone in your topic. There is this ostentatious piece of land called Mexico in the way. Always looking for more geographical knowledge though, if you snuck one by me, or I cheated myself out of a piece of the globe.
Member Since: Posts: Comments:
Quoting 1123. canehater1:
The 11 PM Update from NHC will be interesting.....


Interesting indeed ....wouldn't be surprised if the long range forecast is back to TD status for days 4 and 5
Member Since: Posts: Comments:
Quoting 1102. Grothar:
It looks like one big wave trying to form

Member Since: Posts: Comments:
Quoting 1080. weathermanwannabe:
Having problems with my computer (sorry). If the Gentleman below (OZ) is in fact on the Island; he would be the first Blogger on here from Cuba.......Welcome. Please keep us posted on conditions there as you can over the next few days.


Hi Weather --- actually back several years ago we had an airman from Guatanmo. But it is also neat to see another member.
Member Since: Posts: Comments:
Charleston NWS Discussion:

MAIN FORECAST CHALLENGE THIS PERIOD IS WHAT HAPPENS TO TROPICAL
STORM CHANTAL. THE 12Z/09 GFS...ECMWF AND CANADIAN MODELS ARE IN
FAIRLY GOOD AGREEMENT TAKING THE SYSTEM FROM AROUND THE BAHAMAS
FRIDAY NIGHT TOWARD THE SC/GA COASTS SATURDAY...ALTHOUGH THEY ALL
DIFFER WITH RESPECT TO THE STRENGTH OF THE SYSTEM. THE CANADIAN HAS
PERSISTENTLY BEEN SHOWING A STRONGER SYSTEM MAKING LANDFALL ALONG
THE SC/GA COASTS SO IT MAY BE ON TO SOMETHING. HOWEVER...THERE IS
STILL QUITE A BIT OF UNCERTAINTY REGARDING HOW STRONG THE STORM WILL
BE AFTER HITTING HISPANIOLA AND THUS HOW DEEP OF ATMOSPHERIC FLOW IT
WILL BE STEERED BY. THE MORE NORTHERN TRACK TREND IS CERTAINLY
DISCONCERTING SO WE URGE EVERYONE ACROSS THE AREA TO PAY CLOSE
ATTENTION TO THIS SYSTEM THROUGH THE WEEKEND.

WHETHER CHANTAL REMAINS A NAMED STORM OR NOT THERE WILL STILL BE
QUITE A BIT OF RAINFALL ACROSS THE AREA THROUGH THE WEEKEND AND
POSSIBLY INTO EARLY NEXT WEEK GIVEN THE DEEP TROPICAL MOISTURE
MOVING IN AHEAD OF AN APPROACHING/WEAKENING COLD FRONT WHICH WILL
STALL OUT OVER THE AREA. SEVERAL INCHES OF RAINFALL COULD OCCUR
THROUGH THE PERIOD...WITH EVEN MORE RAINFALL POSSIBLE IN ISOLATED
SPOTS AND ESPECIALLY IF CHANTAL MOVES DIRECTLY TOWARD THE AREA.

Member Since: September 22, 2005 Posts: 18 Comments: 2342
Quoting 1107. cchsweatherman:
May be in the extreme minority in stating this, but given the likely more southern location of the center with Tropical Storm Chantal, Chantal continuing to race off towards the west, and no signs down the road from Chantal of this flow abating soon, I'm finding highly doubtful that Tropical Storm Chantal will cross over Hispanola, but am expecting more and more that Chantal will cross over Cuba at some point, most likely across Central Cuba.


Yes! Check out my post # 1053.
Member Since: Posts: Comments:
The 11 PM Update from NHC will be interesting.....
Member Since: Posts: Comments:
1122. sar2401
Quoting 0z:
Hello, I am a Cuban meteorologist is my first comment on the blog of Jeff Masters, thanks Dr. Masters, I think Chantal did not reach Hispaniola, his career will live to the east of Cuba to go to the Bahamas, and I think also that touched southern Florida, the models will respond to what is making the move west, the trajectory will move west too, remember Hurricane Ivan the model s first pointed east of Cuba, then west and finally barely touch it .
Chantal can still surprise and Dorian watch next week, see you.

Welcome to the Blog. Cuban radar has been a big help to usin the US during hurricane season. Ivan was an amazing storm, but Chantal has to make an almost immeditate and unprecedented move WNW, and maintain that course precisely for almost 700 miles to go between the Yucatan and Cuba and have very little effect or onteraction with either land mass. I can see a cat 4-5 intense hurricane being able to pull that off, but I think Ivan was a once in a lifetime event. I hope Cuba does escape unscathed fomr Chantal, regardless of her ultimate outcome.
Member Since: Posts: Comments:
Quoting 1048. 0z:
Hello, I am a Cuban meteorologist is my first comment on the blog of Jeff Masters, thanks Dr. Masters, I think Chantal did not reach Hispaniola, his career will live to the east of Cuba to go to the Bahamas, and I think also that touched southern Florida, the models will respond to what is making the move west, the trajectory will move west too, remember Hurricane Ivan the model s first pointed east of Cuba, then west and finally barely touch it .
Chantal can still surprise and Dorian watch next week, see you.



terrible grammar, but your Cuban like me so I understand, Gracias !
Member Since: July 21, 2010 Posts: 0 Comments: 1163
Starting to imagine this could be like a Dennis track.
Member Since: Posts: Comments:
Folks in the Florida Keys need to be on close watch with this one; Haiti/Cuba are a half-step away from the chain and I would not let my guard down in the Keys just because the current track is keeping it to Your East.....Things could change quickly on Thursday.
Member Since: Posts: Comments:
Quoting 1048. 0z:
Hello, I am a Cuban meteorologist is my first comment on the blog of Jeff Masters, thanks Dr. Masters, I think Chantal did not reach Hispaniola, his career will live to the east of Cuba to go to the Bahamas, and I think also that touched southern Florida, the models will respond to what is making the move west, the trajectory will move west too, remember Hurricane Ivan the model s first pointed east of Cuba, then west and finally barely touch it .
Chantal can still surprise and Dorian watch next week, see you.
Yeah, I've seen storms throwing curveballs. We'll see. Welcome to WU!
Member Since: Posts: Comments:
Quoting 1107. cchsweatherman:
May be in the extreme minority in stating this, but given the likely more southern location of the center with Tropical Storm Chantal, Chantal continuing to race off towards the west, and no signs down the road from Chantal of this flow abating soon, I'm finding highly doubtful that Tropical Storm Chantal will cross over Hispanola, but am expecting more and more that Chantal will cross over Cuba at some point, most likely across Central Cuba.
That would increase the odds of bringing it into the Gulf.
Member Since: June 30, 2013 Posts: 12 Comments: 8323

Member Since: Posts: Comments:
Member Since: Posts: Comments:
Is recon going home? Looks like they're heading due N. Perhaps instrument issues, though I haven't seen anything in the data about it.

Hope she turns back for another pass or two, She was supposed to stay out there quite a while...
Member Since: Posts: Comments:
More model mayhem, I presume.

We have 2 scenarios:

1, says between Jamaica and Cuba, possibly still headed west, supported by 2 allegedly very good models.

2, The scenario most consistent with NHC, supported by 4 of the models says Hispaniola and then LF on the east coast.




I think those 3 to 5 tenth discrepancies in position, or 10 or 15 compass degree discrepancies in heading could add up to all the difference here. It doesn't matter what steering features are ahead of the storm if the timing is totally wrong when it gets there.
Member Since: January 25, 2012 Posts: 33 Comments: 1520
Lee and Nicole had like 4 centers or vorticies....could be thats what the deal with Chantal.
Member Since: Posts: Comments:
I think Chantal is beautiful.... she has defied all odds, and surprised us all and entertained us all. Anything can still happen in this environment, even slight shifts in speed and direction could change everything. I bet she still has some surprises for us...
Member Since: Posts: Comments:
looks like it's trying to get it's act together again...may get stronger over night
Member Since: Posts: Comments:
Quoting 1098. Hurricanes101:


center is farther south I would say

there have been no hints of even a windshift, I doubt the circulation would have deteriorated that fast

I would say the center is further south than what the nhc had it at
Yeah, center could shift or NHC just marked it wrong. We'll see what recon find after fully studying the storm.
Member Since: Posts: Comments:
Quoting 1078. Levi32:
Good evening.

Blog update:

Tropical Tidbit for Tuesday, July 9th, with Video

Thanks for the update.
Member Since: Posts: Comments:
May be in the extreme minority in stating this, but given the likely more southern location of the center with Tropical Storm Chantal, Chantal continuing to race off towards the west, and no signs down the road from Chantal of this flow abating soon, I'm finding highly doubtful that Tropical Storm Chantal will cross over Hispanola, but am expecting more and more that Chantal will cross over Cuba at some point, most likely across Central Cuba.
Member Since: Posts: Comments:
Quoting 1078. Levi32:
Good evening.

Blog update:

Tropical Tidbit for Tuesday, July 9th, with Video



Tks Levi!
Member Since: Posts: Comments:
Quoting 1101. CycloneOz:


Was not the center reported at 15.1N 65.1W?


BULLETIN
TROPICAL STORM CHANTAL INTERMEDIATE ADVISORY NUMBER 8A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032013
800 PM AST TUE JUL 09 2013

...CHANTAL HURRYING ACROSS THE EASTERN CARIBBEAN SEA...


SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...15.4N 64.9W
ABOUT 220 MI...360 KM SSE OF SAN JUAN PUERTO RICO
ABOUT 395 MI...635 KM ESE OF SANTO DOMINGO DOMINICAN REPUBLIC
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 26 MPH...43 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting 1048. 0z:
Hello, I am a Cuban meteorologist is my first comment on the blog of Jeff Masters, thanks Dr. Masters, I think Chantal did not reach Hispaniola, his career will live to the east of Cuba to go to the Bahamas, and I think also that touched southern Florida, the models will respond to what is making the move west, the trajectory will move west too, remember Hurricane Ivan the model s first pointed east of Cuba, then west and finally barely touch it .
Chantal can still surprise and Dorian watch next week, see you.


No le tema de hablar en espanol...mas personas que Ud. cree van a entederle (y las otras pueden usar google translate). Cuidese con Chantal porque parece que ella va a pasar por su isla, y bienvenidos al blog!
Member Since: Posts: Comments:
1102. Grothar
It looks like one big wave trying to form

Member Since: July 17, 2009 Posts: 71 Comments: 26151
Quoting 1093. Bluestorm5:


NHC marked the center at 15.4 N. They've gone south and north of that so far. Either there's no center, small center, or center is farther south.


Was not the center reported at 15.1N 65.1W?
Member Since: Posts: Comments:
Enjoy the golf and the gals ....pressure is on the up and up!
Member Since: Posts: Comments:
Quoting 1054. gulfbreeze:
What affect will the ULL have on Chantal?


It is creating the weakness in the ridge off the coast of FL that Chantal will be moving towards....The big issue is whether the ridge will build back in forcing the storm towards Fl or GA......It boils down to the timing.
Member Since: Posts: Comments:
Quoting 1093. Bluestorm5:


NHC marked the center at 15.4 N. They've gone south and north of that so far. Either there's no center, small center, or center is farther south.


center is farther south I would say

there have been no hints of even a windshift, I doubt the circulation would have deteriorated that fast

I would say the center is further south than what the nhc had it at
Member Since: Posts: Comments:
South of initialization should see the ensemble members and the mean adjust to that in the next run could be more left.

Member Since: June 30, 2013 Posts: 12 Comments: 8323
1096. JLPR2
So no vortex message for the moment...

Maybe Chantal ditched her LLC?
Member Since: September 4, 2007 Posts: 7 Comments: 8698
Thanks Levi for the update
Member Since: Posts: Comments:
1094. Grothar
Quoting 1082. presslord:


Stop it


too late.
Member Since: July 17, 2009 Posts: 71 Comments: 26151
Quoting 1085. Hurricanes101:


they have been investigating the northern part this whole time, they havent gone further south yet


NHC marked the center at 15.4 N. They've gone south and north of that so far. Either there's no center, small center, or center is farther south.
Member Since: Posts: Comments:
Standby...

The 07/09/2013 Daily Update of the GOES East Infrared Hurricane Sector Animation is uploading to YouTube.

It will be ready momentarily...
Member Since: Posts: Comments:
Quoting 1088. redwagon:


God alone knows what DMAX will bring.



...and Grothar. or are they one in the same?
Member Since: Posts: Comments:
SPC was kind of all over the place today with their tornado probabilities..

Member Since: Posts: Comments:
1089. Grothar
It looks like Chantal had a convective burst about 30 minutes ago.

Member Since: July 17, 2009 Posts: 71 Comments: 26151
Quoting 1066. will40:


i agree i think she knows exactly what she is doing


God alone knows what DMAX will bring.
Member Since: Posts: Comments:


LARGER VIEW SFC MAP

There will be no effect, imo, from the CONUS mid-latitude trough - see "disipating" over Kansas, and also see the tongue of GoM high pressure extending more southwesterly. The only weakness that remains is the ULL and it's retrograding more southwesterly with 1020mb ridge building back in behind it. I expect a continuing more westerly shift in track forecasts. Chantal, if she can hold it together (and I think she will), should cross over eastern-to-central Cuba, imo.

I'ma be quiet now and let some of the smarter folks explain it to us. Honestly, among many of my weaknesses, troughing and how it affects track is my weakest. No matter, hurt, even if it's flooding only, is straight ahead for some folks, somewhere soon.
Member Since: July 9, 2006 Posts: 184 Comments: 29610
Quoting 1067. all4hurricanes:
What did Recon find in Chantal?


Member Since: Posts: Comments:

Viewing: 1136 - 1086

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

Mostly Cloudy
72 °F
Mostly Cloudy