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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Quoting 128. PalmBeachWeather:
Clapton joined him (Yardbirds) Jimmy Page was in the audience


What's this? I gotta get out more.
Member Since: October 18, 2005 Posts: 4 Comments: 3052
Hello Ike, Patrap. Looks Like there is a little excitement around here about some clouds and rain out in the ocean.
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Quoting 130. daddyjames:


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


That has been going on already for as long as Energy Traders have existed.
Member Since: September 23, 2005 Posts: 15 Comments: 11341
Quoting 121. Patrap:


Its making slow progress West by Sw seems today.



That's why I'm not a weather expert. They've been sayin' Wednesday, but I wouldn't listen! We do have a few popcorn jobs passing thru...
Member Since: October 18, 2005 Posts: 4 Comments: 3052
I just hope Chantal doesn't find a sweet spot anywhere down the line or try to thread the mona passage. I'd hate to see what she would be right now with even decent conditions.
Member Since: August 19, 2005 Posts: 5 Comments: 5458
Looks like Chantal is wanting to rev up a bit now. If she diverges even a little from the models, could place her into the GOM for another scary scenario - yikes!

Btw, "Chantal"? What about "Cheneynay" or "Chenoqui" or "Cleopatra"?
Of course, we are totally ignoring native Americans altogether by not calling it "Clenches-Her-Fist", "Craves-Your-Coastline", or "Crazy-Crow-Woman".
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Quoting 122. nrtiwlnvragn:
This Hurricane Season Energy Traders Have New Forecast Tool

Excerpt:

The Department of Energy has just released a nifty new tool energy-market watchers may find useful this hurricane season.

It contains real-time information on tropical storms from the National Hurricane Center overlaid on a map of major U.S. energy infrastructure sites, including oil and gas rigs in the Gulf of Mexico, oil import sites, oil refineries, power plants and other facilities.


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

Velocity Azimuth Display Wind Profile ° Elevation
Range 124 NMI

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Quoting 123. IKE:

No I didn't. Sorry I missed it.
Clapton joined him (Yardbirds) Jimmy Page was in the audience
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Afternoon all.

Utterly shocked and surprised actually, to find that we still have chatnal today. After the COC started outrunning the system last night due to westerlies and high speed I was almost certain that we would be a dissapating trend today.

Furthermore I expected the storm to be significantly farther north by now.

Chantal it seems, is not disappointing in the "Hard to track hard to forecast tricky dynamic storm" category, as we see today not only has it strengthened despite its bizzare central pressure and sat appearance, it is also much further west than expected, with model guidance now becoming even more uncertain after three days, if that were even possible.



One thing is for sure, chantal is a drama queen and will dance until the final curtain call. We haven't seen even half of this saga yet, so its going to get really interesting in the next few days.

The biggest concern I have right now is guidance. No real idea where exactly this is going to end up and we probably won't know that until it gets there. Hopefully some of the models can get a better grip over 36 hours but that remains to be seen; namely if the storm had a lower central pressure and was better organized this would probably improve the grasp the guidance models have over it, I imagine that high central pressure is playing a large role in confusing the guidance scenario we have now.
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Quoting IKE:


Chantal is now approaching PR's radar. It would have been good if the Punta Cana radar in Dom Rep was up and running.
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Quoting 119. Dakster:

Taz is that a pinhole eye I see?




LOL
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123. IKE

Quoting PalmBeachWeather:
IKE.Did you see Jeff Beck in concert on TV the other night? Great
No I didn't. Sorry I missed it.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
This Hurricane Season Energy Traders Have New Forecast Tool

Excerpt:

The Department of Energy has just released a nifty new tool energy-market watchers may find useful this hurricane season.

It contains real-time information on tropical storms from the National Hurricane Center overlaid on a map of major U.S. energy infrastructure sites, including oil and gas rigs in the Gulf of Mexico, oil import sites, oil refineries, power plants and other facilities.
Member Since: September 23, 2005 Posts: 15 Comments: 11341
Quoting 116. mikatnight:


I keep expecting that big blob associated with the ULL to circle over get everybody wet, but it just sort of hangs there...


Its making slow progress West by Sw seems today.

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I really like Janice Dean from Fox network.To bad she can't be on stations where she'll be more useful.She was also talking about not only Chantal but to keep an eye on the wave behind her.
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Taz is that a pinhole eye I see?
Member Since: March 10, 2006 Posts: 0 Comments: 10747
Quoting 108. IKE:

IKE.Did you see Jeff Beck in concert on TV the other night? Great
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Quoting 92. Tazmanian:
when is the 18z?


18z
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Quoting 104. Patrap:
The ULL has entered the Florida Straits

Western Atlantic - Visible Loop

ZOOM is active


I keep expecting that big blob associated with the ULL to circle over get everybody wet, but it just sort of hangs there...
Member Since: October 18, 2005 Posts: 4 Comments: 3052
If she can keep the breathing going as she has today and keep the Western quad moist, we "should" see a system more becoming of a 65mph TS tomorrow morning.

Member Since: August 19, 2005 Posts: 5 Comments: 5458
Quoting 112. whitewabit:


commenting in upper case is RUDE ..

this needs to stop !

I reported him.
Member Since: June 14, 2013 Posts: 2 Comments: 2002
Quoting 108. IKE:




well well well look oh came out of hiding



hi ike
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112. whitewabit (Mod)
Quoting 102. jeffreeysweetypie:
STOP IT ALREADY


commenting in upper case is RUDE ..

this needs to stop !
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Quoting 74. SecretStormNerd:


It would seem youre trolling. Unless you like making the same comment 60 times in one day? All of the models have said Florida for days. I'm sorry this makes you sad. Get over it.


He's been doing that for a couple of days now. Just 'Iggy-Poof' and things get better.

In your previous post you said you were getting ready with some storm preps. Being in FL that's the correct thing to do. If not needed for this storm then certainly the next.

Yes, "Florida for days..." Pay attention to your local mets. and other officials. This blog is a great place to visit for both information and misinformation. Once you can tell one from the other then it becomes a better place.

Welcome to the wunderground romper-room.
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108. IKE

Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting 100. Camille33:
Lets remind people that Chantal is a very small system and these systems can intensify fast given the right set of circumstances present.
Might want to reconsider saying "very small system" as it is currently in the process of expanding in areal coverage.
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Quoting 89. jeffreeysweetypie:
dude yesterday the track was north of P.R. today its going all along P.R. AND THE DOMINICAN cant see it staying together going over all that land now plus its a pathetic weak storm to begin with


Yes, Hispaniola may chew her up and spit her out. And the models are going to jump about a bit as it is all dependent upon timing of the ULL, the upper ridge building back in, and where and what shape Chantal may be. So,nothing to be critical about that.

And, Mr. Observent, if the avat is any indicator - SSN is far from being a dude.
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The ULL has entered the Florida Straits

Western Atlantic - Visible Loop

ZOOM is active
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Quoting 100. Camille33:
Lets remind people that Chantal is a very small system and these systems can intensify fast given the right set of circumstances present.

And moving rapidly at 29mph with shear and dry air aren't those circumstances.
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Lets remind people that Chantal is a very small system and these systems can intensify fast given the right set of circumstances present.
Member Since: July 2, 2013 Posts: 0 Comments: 1523
COC is apparent in this Satellite image.
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Ok let's see what happens in the next runs...

But the idea of seeing Chantal just south and not delivering anything... then seeing that fish on the GFS is very frustrating.

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Quoting 91. SecretStormNerd:


Thankfully I live on the outer edge of Greenacres as it is not the place to be :-) Why do these storms always hit us on a weekend? lol
I have always wondered that myself......Boynton Beach Blvd...Just west of Jog
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First time Chantal has been able to fire convection in all quadrants. Likely the result of the good convergence/divergence she's had today.

Member Since: August 19, 2005 Posts: 5 Comments: 5458
FQNT52 LFPW 092006
Weather bulletin on METAREA 2,
METEO-FRANCE Toulouse, Tuesday 9 July 2013 at 2215 UTC.

Tropical wave extending from 16N 19W to 08N 20W drifting west.

Tropical wave extending from 11N 32W 05N 33W, moving west 15-20 kt.
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when is the 18z?
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Quoting 82. PalmBeachWeather:
Green Acres is the place to be...Farm livin' is the life for me....Boynton here


Thankfully I live on the outer edge of Greenacres as it is not the place to be :-) Why do these storms always hit us on a weekend? lol
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if the BAMS model should hold through...Chantal is gonna have to pay some tolls......
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Quoting 71. CaribBoy:
12Z GFS .... no Dorian in the MDR, it shows a fish.

It sent it right into the same strong ridge that is in the Atlantic right now. I doubt that would actually happen.
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Quoting 79. TropicalAnalystwx13:

If by developing an eye you mean developing a dry spot from recently-collapsed thunderstorms, then yes, I guess it is developing an "eye".

If you mean the clear spot at the center of a tropical cyclone with deep thunderstorm activity surrounding it, then you would be incorrect.

Amen.
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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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