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: 386 - 336

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

Quoting 383. Patrap:




The SW turn at the end of several of those runs is interesting.
Member Since: Posts: Comments:
to me Chantal is looking better....may see the wave behind it get a yellow circle soon
Member Since: Posts: Comments:
63 hrs. still recovering from getting torn up over Haiti and Cuba.

Member Since: Posts: Comments:


Member Since: Posts: Comments:
Quoting 366. WalkingInTheSun:
Wow, my last peek at Chantal suddenly makes her look like she could fizzle on us. Another swirly blogularity off the SE tip of Florida is catching my attention, however. What's the chance of it doing something -- possibly in the GOM side?
Btw, if it increases, could it "deflect" Chantal to a more southerly route?


That blogularity is an upper vortex trying to build to low-levels...perhaps becoming a subtropical or tropical cyclone.

During past days...CMC model suggested it would develop when it moved into the eastern Gulf of Mexico in the timeframe that is now 48 hours away. Didn't check on CMC model today....but if this developed into "Dorian" than Dorian's east side would instead try to deflect Chantal more northward if anything....
Member Since: Posts: Comments:
Quoting 376. Chicklit:
This is Chantal currently.


Convection has wane but look at the increase in size
Member Since: Posts: Comments:
Re-hi everyone. I've been gone all day and just read back a couple of pages, but didn't see a whole lot on what Chantal is doing, where she is or where they think she is going?
Member Since: Posts: Comments:
379. A4Guy
this does notlook like a cyclonic storm...looks like a mess...or an open wave!
Member Since: Posts: Comments:
Dorian starting to gather in 30 hours!! no way!!!
Member Since: Posts: Comments:
Quoting 330. MechEngMet:


If you're BVI you should be fine from this one. Unless something changes, of course. Keep an ear to your local officials.


Actually, no. USVI over here, St. Thomas. It's always the "unless something changes" that makes us pull the boats. No one in their right mind wants to have to do that in the dead of night. Better safe than sorry is what we say.

-L
Member Since: Posts: Comments:
This is Chantal currently.

Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting 366. WalkingInTheSun:
Wow, my last peek at Chantal suddenly makes her look like she could fizzle on us. Another swirly blogularity off the SE tip of Florida is catching my attention, however. What's the chance of it doing something -- possibly in the GOM side?


That is an ULL that has been working its way westward over the last couple of days towards Florida. No chance of development from it, no surface circulation present and it is too close to Florida to obtain one.
Member Since: Posts: Comments:
Quoting 366. WalkingInTheSun:
Wow, my last peek at Chantal suddenly makes her look like she could fizzle on us. Another swirly blogularity off the SE tip of Florida is catching my attention, however. What's the chance of it doing something -- possibly in the GOM side?


Blogularity?
Member Since: Posts: Comments:
Very Interesting about the weird shear that was discovered from a weather balloon release..
Member Since: Posts: Comments:
Speaking of T-storms,



Member Since: Posts: Comments:
Quoting 359. MiamiHurricanes09:
Not really. Pretty much the same as the 12z run 21 hours out:



It still take it over DR which is on right side of the models.
Member Since: Posts: Comments:
Quoting 311. GTstormChaserCaleb:
No wonder the Eastern Caribbean is called the "Dead Zone" convection starting to wane.



Bamm a wall and implosion Not looking like a TS at all and probably isnt if we had recon there now
Member Since: Posts: Comments:
Quoting 358. GTstormChaserCaleb:
30 hrs. looks like the system gets tangled up over Hispaniola.

Dorian starting to gather.
Member Since: August 14, 2010 Posts: 10 Comments: 17836
Quoting 354. Dakster:


I'll let you light the match...


It must have a heavier hydrocarbon in it than just methane or ethane(natural gas) if it is leaving a sheen. Otherwise it would just dissipate into the atmosphere
Member Since: Posts: Comments:
Wow, my last peek at Chantal suddenly makes her look like she could fizzle on us. Another swirly blogularity off the SE tip of Florida is catching my attention, however. What's the chance of it doing something -- possibly in the GOM side?
Btw, if it increases, could it "deflect" Chantal to a more southerly route?
Member Since: Posts: Comments:
365. whitewabit (Mod)
Oil Well Leaking in the Gulf
Member Since: Posts: Comments:
Quoting 359. MiamiHurricanes09:
Not really. Pretty much the same as the 12z run 21 hours out:



Short-term track is a bit to the right of the 12z.
Member Since: Posts: Comments:
Quoting 354. Dakster:


I'll let you light the match...


I'm sorry, but that is a funny line.
Member Since: July 17, 2009 Posts: 71 Comments: 27210
Quoting 347. RitaEvac: If it's natural gas and floating on the surface, then burn it

Natural gas floats on water? Maybe condensate or a bit of liquid hydrocarbons.
Member Since: Posts: Comments:
Quoting 357. Hurricanes305:


Yes and notice the upper low to it east that may ventilate it.


That's only going to help her if she can re-fire thunderstorms prior to the upper low cutting off over the SE US. Without a self-induced heat bubble on top of her, the col in the 200mb pattern won't help her much. She's going to have to do some work first.
Member Since: Posts: Comments:
From colorized infrared perspective...Chantal is one of the ugliest looking 65 mph tropical storm I've seen. It has intesnfied more than I predicted it would this morning...hmmmm....

Maybe she intensified because of her acceleration in forward speed? (she went from 25 to 30 mph forward speed earlier today)....
Member Since: Posts: Comments:
Quoting 352. Hurricanes305:


much more stronger now!
Not really. Pretty much the same as the 12z run 21 hours out:

Member Since: Posts: Comments:
30 hrs. looks like the system gets tangled up over Hispaniola.

Member Since: Posts: Comments:
Quoting 353. Levi32:
There is one factor possibly in favor of Chantal redeveloping on the other side of the mountains. The inverse ridge axis digging in behind Chantal is forecasted by both the GFS and CMC to help angle the Caribbean low-mid level jet northward over Haiti and Cuba and into Chantal. The result is weak trade winds over the western Caribbean, and the moist flow from the Caribbean converges in the vicinity of Chantal. This could possibly help her maintain convection after being ripped by the mountains.

GFS 850mb winds at 63 hr:



Yes and notice the upper low to it east that may ventilate it.
Member Since: Posts: Comments:
Quoting 130. daddyjames:


So the inflated panic that occurs on this blog will now be out-matched by the inflated panic in the marketplace? Fantastic. ;)

Information prevents panic. Panic comes from uncertainty.
Member Since: Posts: Comments:
Quoting 341. Dakster:


Just what LA needs... This could totally annihilate the tourism and fishing industry in Louisiana.


Been there done that. This doesn't sound even close to BP. (yet)
Member Since: Posts: Comments:
Quoting 347. RitaEvac:
If it's natural gas and floating on the surface, then burn it


I'll let you light the match...
Member Since: March 10, 2006 Posts: 0 Comments: 10810
There is one factor possibly in favor of Chantal redeveloping on the other side of the mountains. The inverse ridge axis digging in behind Chantal is forecasted by both the GFS and CMC to help angle the Caribbean low-mid level jet northward over Haiti and Cuba and into Chantal. The result is weak trade winds over the western Caribbean, and the moist flow from the Caribbean converges in the vicinity of Chantal. This could possibly help her maintain convection after being ripped by the mountains.

GFS 850mb winds at 63 hr:

Member Since: Posts: Comments:
Quoting 337. GTstormChaserCaleb:
18z GFS out to 12 hrs.



much more stronger now!
Member Since: Posts: Comments:
Quoting 334. Dakster:


I would do the same thing, My comment was not a complaint, just an observation in their behavior.


I gotcha, I do the same sometimes.
Member Since: Posts: Comments:
The well in the Gulf is an old well they were capping off from what I've read. Hopefully they will regain control of it today.
Member Since: Posts: Comments:
Quoting 329. whitewabit:


Models always seem to have trouble with weak storms ..


Once a storm is strong, all the forecast is really would be timing and "everyone take cover". For weak storms you have to consider strengthening, dissipation, timing, and all sorts of nit-picky items. Not to put down a strong storm or anything with relation to the models.
Member Since: Posts: Comments:
chantal is dying
Member Since: Posts: Comments:
If it's natural gas and floating on the surface, then burn it
Member Since: July 14, 2008 Posts: 2 Comments: 9686
Quoting 308. weatherlover94:
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


Of course he said it could be a disaster. How do you think TWC makes $$$
Member Since: Posts: Comments:
NEW ORLEANS (AP) - The Coast Guard says natural gas is leaking from a well at a production platform in the Gulf of Mexico 74 miles southwest of Port Fourchon, La.

Chief Petty Officer Bobby Nash says the well is not spewing, but a rainbow sheen four miles wide and three-quarters of a mile long was spotted in an aerial survey Tuesday.

The platform owner was identified as Energy Resources Technology Gulf of Mexico LLC. The company could not immediately be reached for comment.

Link
Member Since: Posts: Comments:
Quoting 318. weatherh98:


Has more to do with tradewinds killing the coc


Trade winds is helping it with its strong wind in the northern side. It has more to do with collapsing convection creating downdrafts along with DMIN thus convection has waned but the storm is still gaining size and structure as it has slow down and allow convergence to lift and spread out thus increasing the cloud mass. We will see how DMAX treat it as it would provide and extra lift to get those cloud tops cold.
Member Since: Posts: Comments:
Quoting 329. whitewabit:


Models always seem to have trouble with weak storms ..


It makes sense because they have a very disorganized center or multiple centers which can lead to mathematical issues. This can lead to significant error.
Member Since: Posts: Comments:
Quoting 333. allancalderini:
Do you have Robbie Berg?
Nope, he didn't do a PSA.

All of the ones in English are here:

https://www.youtube.com/playlist?list=PL63A9138A2 047B1A4
Member Since: Posts: Comments:
Quoting 335. Luisport:
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.


Just what LA needs... This could totally annihilate the tourism and fishing industry in Louisiana.
Member Since: March 10, 2006 Posts: 0 Comments: 10810
Thanks everyone.
Member Since: August 14, 2010 Posts: 10 Comments: 17836
Models are being based on a circulation that doesn't really exist and it's a vort circulation more than anything....so it means throw all the models out. As long as it trucks along at a minimal 20mph the farther west in longitude she's gonna go, which will make the models keep playing catch up just following the storm.
Member Since: July 14, 2008 Posts: 2 Comments: 9686
Quoting 317. BaltimoreBrian:


Surviving being a boy named Stacy would make you tough!


"Yup!" "Boy named Sue" Country song.

Low 90's, nice lake breeze from the north, and 'severe clear' in NOLA. -Cocktail time!
Member Since: Posts: Comments:
18z GFS out to 12 hrs.

Member Since: Posts: Comments:
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:

Viewing: 386 - 336

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
39 °F
Overcast

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron