Unusual Chantal Disorganized, but has 65 mph Winds

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

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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

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They do have south winds at 16.0W 70.8N

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Quoting 2167. Tazmanian:




can you plzs font Quote him many of us have him on ignore all so plzs dont feed the troll


Taz, you jumped all up in someone's business yesterday for someone saying not to quote you because of the same reason.

Now today, with the shoe on the other foot, you find it completely appropriate to tell someone else to not quote someone.

As much as you would love to be one; You are not a mod.

Stop with the blog police nonsense. It is very tiring to see you not following the 'rules' you hold other posters to...
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Quoting 2171. MisterPerfect:


2158. jeffreeysweetypie 12:13 PM GMT on July 10, 2013 +0
I called it 3 days ago right on the head. chantal will fall apart and not do much to florida post # 1344 and # 1780 last sunday ( rest my case )




i dont want too see is freaking commets and your not being funny at all the olny thing you are freaking doing is feeding a troll that many of us had too put on Ignore he was be so annyouing on sunday with his commets and he is still doing the same today that many of us had too put him on Ignore
Member Since: May 21, 2006 Posts: 5091 Comments: 115456
Chantal at her strongest according to the 6z GFDL



And the HWRF...A whopping 26kts...



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Here is the WU link to Port au Prince weather
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Quoting 2142. SouthernIllinois:

You gotta meet up with PensacolaDoug and have a drink sometime. You two would hit it off. I just know it!!! :-)

Natalie


LOL Nat, probably. I was just throwing it out there. This storm ha defied everything that the books said should happen with it.
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its more like Tropical wave CHANTAL!!
Member Since: March 12, 2013 Posts: 113 Comments: 106802
2178. pcola57
Quoting 2148. washingtonian115:
That wave off Africa is more interesting then Chantal and vorticity is starting to stack.I wonder when the NHC will high light it.Thats the real threat there.


Morning Washi..

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2177. LemieT
Quoting 2162. Levi32:
Good morning. Well, I knew Chantal was going to struggle, but losing every last cumulonimbus cloud for a few hours was a little over the top, even for my expectations lol. Chantal may be done for good at this rate.


You're right Levi, that loss of thunderstorms was pretty dramatic. Chantal has never had life easy, it's a wonder that she formed at all. I think the take away from here is that we need to keep our eyes open for the rest of the season. It wouldn't surprise me to see perhaps 2 more storms of greater organization and intensity, traverse a similar path to the Chantal later in the season.
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Ernesto did this when he was a storm...blew apart near Honduras. We thought he was done for (so did the NHC) but he quickly gathered together and became a Cat 2.
Chantal won't make a cat 2 but a recovery like Ernesto's is possible once it moves away from Cuba.
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What ever is left of chantal, Cuba will knock down. Maybe boaters in the Keys should avoid the water whent he depression comes ashore, all else...easy street. Thank you wind shear, good job. NEXT!!
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There is still a low level circulation, but it's pretty weak looking. It poped out of the convection earlier this morning, and is now covered by clouds from a burst of convection around 8:45UTC. Look at the Visible Satellite Image Loop from 7:15UTC to 8:45 UTC and you can make it out..



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Quoting 2162. Levi32:
Good morning. Well, I knew Chantal was going to struggle, but losing every last cumulonimbus cloud for a few hours was a little over the top, even for my expectations lol. Chantal may be done for good at this rate.
still be a rain storm!!
Member Since: March 12, 2013 Posts: 113 Comments: 106802
Quoting 2155. bdm2225:
Approaching hurricane strength, now maybe open tropical wave. Dying storm, now popping convection again. She can't decide what she wants to do and where she wants to go, but us here in Port-au-Prince would like to know ASAP! Any ideas?

I would prepare for heavy rain showers. Hopefully, not for too long but long enough to cause some misery.
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Quoting 2167. Tazmanian:




can you plzs font Quote him many of us have him on ignore all so plzs dont feed the troll


2158. jeffreeysweetypie 12:13 PM GMT on July 10, 2013 +0
I called it 3 days ago right on the head. chantal will fall apart and not do much to florida post # 1344 and # 1780 last sunday ( rest my case )
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Forsooth, the Blahamab dost seem to portend the actions of Chantal in that it fizzles and lurches closer to Florida erratically.
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Quoting 2165. SouthernIllinois:

What about your Chuckshirt. Can Jeffrey have that? LOL


I love my chuck shirt. we all should get one!
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following NHC coordniates and present movement Chantal would move S of Jamaica or on Southern half

on another note I do see a spin on rgb and shortwave loops not too sure whether its mid level or ground anyway its near where convection is now building it appears to be moving W
Member Since: June 13, 2009 Posts: 2 Comments: 12719
Quoting 2160. MisterPerfect:


Congratulations! You get a single Apple Jack for your win. Enjoy :)




can you plzs dont Quote him many of us have him on ignore all so plzs dont feed the troll
Member Since: May 21, 2006 Posts: 5091 Comments: 115456
Tropical wave CHANTAL!!
Member Since: March 12, 2013 Posts: 113 Comments: 106802
She's going to have to slow down and take a right to keep on the 800 track.
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I am glad to see Chantal has spun herself into disorganization. We will welcome her depression of rain soon in Florida.
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2162. Levi32
Good morning. Well, I knew Chantal was going to struggle, but losing every last cumulonimbus cloud for a few hours was a little over the top, even for my expectations lol. Chantal may be done for good at this rate.
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I just want a straight forwards storm.I hate ones like Chantal,because after a while it feels like your playing mind games with a child.
Member Since: August 14, 2010 Posts: 10 Comments: 17836
Quoting 2158. jeffreeysweetypie:
I called it 3 days ago right on the head. chantal will fall apart and not do much to florida post # 1344 and # 1780 last sunday ( rest my case )


Congratulations! You get a single Apple Jack for your win. Enjoy :)
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Quoting 2156. SouthernIllinois:

Hey Doug. :)


G' morning. I'm only here for a sec. It's off to work for me!
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Quoting 2111. StormJunkie:


Sounds like that is the case all the way through the Carolinas too.

Oh, WTH...Now Firefox is telling me I misspelled Carolinas...
Obviously press has some pull @ firefox... lol
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2155. bdm2225
Approaching hurricane strength, now maybe open tropical wave. Dying storm, now popping convection again. She can't decide what she wants to do and where she wants to go, but us here in Port-au-Prince would like to know ASAP! Any ideas?
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Quoting 2134. weatherh98:


Methinks the "center" (if you can call it so) is a little off










As are most of us.
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Quoting 2145. Grothar:
This shows the weakness where the system could begin turning.




This one is more appropriate for a very weak system, IMO.

That one you posted is for pressure under 940mb...

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At least Emily if 11 spawned a bunch of storms

I don't think Chantal can pull that one off
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No rotation where the center is supposed to be
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Quoting 2141. Grothar:


Dost thou?


I mean

I'm sure I could find some Shakespeare around here somewhere

*looks frantically through Romeo and Juliet*

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That wave off Africa is more interesting then Chantal and vorticity is starting to stack.I wonder when the NHC will high light it.Thats the real threat there.
Member Since: August 14, 2010 Posts: 10 Comments: 17836
Finally getting some breakfast... whole wheat pancakes with dates and raisins, maple syrup, and, of course coffee...
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Don't be dissapointed folks........There will be plenty of viable hurricanes to track this season....... :)
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2145. Grothar
This shows the weakness where the system could begin turning.


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The center wouldn't reform under the convection would it? lol
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She still outflow dominant, the "center" is unrecognizable in the nhcs location, and this "storm" is an open wave
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2141. Grothar
Quoting 2134. weatherh98:


Methinks the "center" (if you can call it so) is a little off


Dost thou?
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Appears Chantal (or whatever's left) has moved, yet again, left of the NHC track. IF there is a center, it might not even hit Haiti..
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BULLETIN
TROPICAL STORM CHANTAL INTERMEDIATE ADVISORY NUMBER 10A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032013
800 AM EDT WED JUL 10 2013

...CHANTAL MOST LIKELY A TROPICAL WAVE...
...RECONNAISSANCE PLANE EN ROUTE TO VERIFY...
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Well I see everyone is here this morning... :-)
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2137. Relix
Emily's twin!
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Good morning, Press. And Ike. And StormJunkie (somehow just typing Junkie didn't seem quite the thing!).

While an open wave might bring a sigh of relief to some, the rain could still be copious, which Florida does NOT need at the moment. Georgia and SC don't need any more, either...
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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