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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Venezuela didn't want the hurricane hunter's to find Snowden.
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Quoting 1455. GTstormChaserCaleb:
Wait what air space restriction from who?

HOWEVER...AIR SPACE
RESTRICTIONS PREVENTED THE PLANE FROM SAMPLING THE AREA FARTHER
SOUTH.
Apparantly Atlantis.
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Such a shame for real that we still have these problems.
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Quoting 1446. MiamiHurricanes09:
Is that new? Never seen that happen before.


Last year HH wouldn't breach Mexico airspace one hair over that storm that ran in to Tampiqul(&^*) and came back to be renamed... was it Ernesto?
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1482. Patrap
San Juan
NEXRAD Radar

Base Reflectivity 0.50° Elevation
Range 248 NMI

Member Since: July 3, 2005 Posts: 426 Comments: 128654
1481. ncstorm
LOL..I thought Chantal was a hot mess but this blog beats her by a landslide..
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Quoting 1464. Dakster:
11pm Important note about track:

BASED ON AVAILABLE
AIRCRAFT DATA THE CENTER IS RELOCATED A BIT TO THE SOUTH RELATIVE
TO THE PREVIOUS TRACK...WHICH HAS A RESULTED IN SOUTHWARD AND
WESTWARD SHIFT OF THE FORECAST TRACK THROUGH 36 HOURS. A STRONG
SUBTROPICAL RIDGE GUIDING CHANTAL RAPIDLY WEST-NORTHWESTWARD IS
FORECAST TO WEAKEN AND SHIFT EASTWARD AS A PRONOUNCED WEAKNESS
DEVELOPS ALONG THE UNITED STATES EAST COAST AND EXTENDS SOUTHWARD
INTO FLORIDA. THIS SHOULD RESULT IN THE TRACK OF CHANTAL BENDING
NORTHWESTWARD AND THEN NORTHWARD AFTER 36 HOURS. THE OFFICIAL
TRACK FORECAST LEANS ON THE WEAKER GFS SOLUTION WHICH HAS A
SHALLOWER CYCLONE BEYOND 48 HOURS.




Defenitly, the models began there shift today( the first 36 hours) watch for the northen half after cuba to shift tommoro. Either way gota wait and see.
Member Since: July 21, 2010 Posts: 0 Comments: 1177
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Dont know what to say this could be a weak TS right now. 60mph is probably too generous but it would've have been great to get some feedback I dont understand the Airspace problem as they should have known about this before wasting their time. Does this mean no Recon till it is further west. What about future storms in that vicinity.
Member Since: May 25, 2012 Posts: 0 Comments: 2043
1477. bappit
Quoting 1452. washingtonian115:
Nope.Depending on air traffic restrictions can happen.

Snowden on a plane near there?
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Quoting 1431. stormpetrol:

11:00 PM AST Tue Jul 9
Location: 15.3°N 66.2°W
Moving: WNW at 28 mph
Min pressure: 1009 mb
Max sustained: 60 mph

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 INCH, kinda dumbfounded here, movement still WNW, ???

yeah I know even that it not the right cordinate

Quoting 1432. cchsweatherman:
The latest discussion for Chantal explained why they never entered the southern part of the storm; apparently there are air space restrictions, so they could not cross 15 N.


well ok let us all just scrap the 11pm update and forecast and movement because NHC has no clue where the LLCOC is and forecast is just screwed
Member Since: June 13, 2009 Posts: 2 Comments: 12151
Shameful! Total BS IMO.
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Thunderstorms warmed. Lights are dim, crowd is settled, and the fat lady is ready to appear from stage left.

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Quoting 1461. scottsvb:



That's a load of crap...they are not even near Venez


200 mile limit remember? But it is crap, Venezuela's been doing that for years. Even Cuba lets our recon in their airspace! (although not over land)

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Good evening everyone

I personally think that the HH's need to have a direct link to this blog. As they're flying through it they can see you guys saying "go south", "go east"..... just kidding, of course!

Very quiet over here, except a few good gusts of wind.

Lindy
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What if Chantal is another Fay?
the path 5-7 days out looks a little wonky she might make some sharp turns
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Quoting 1450. redwagon:


Radar close to the storm is the only way we're going to be able to figure this out.


Is there any radar within range? If anyone can post a link, thanks in advance
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Quoting 1461. scottsvb:



That's a load of crap...they are not even near Venez
Perhaps someone needs to consult the president we're paying for these missions out there.
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THE SATELLITE PRESENTATION OF CHANTAL BECAME LESS ORGANIZED DURING
THE LATE AFTERNOON AND EARLY EVENING...BUT THERE HAS BEEN A BURST
OF DEEP CONVECTION RECENTLY NEAR THE ESTIMATED CENTER. THE PLANE
HAS HAD DIFFICULTY FIXING A CENTER...WITH THE WIND FIELD RESEMBLING
AN OPEN WAVE RATHER THAN A CLOSED CIRCULATION. HOWEVER...AIR SPACE
RESTRICTIONS PREVENTED THE PLANE FROM SAMPLING THE AREA FARTHER
SOUTH...SO IT IS INCONCLUSIVE AS TO WHETHER A CLOSED CIRCULATION
STILL EXISTS.
AIRCRAFT DATA ALSO SUGGEST THAT SOME WEAKENING HAS
TAKEN PLACE...WITH PEAK 850 MB FLIGHT-LEVEL AND BIAS-CORRECTED SFMR
WINDS OF 50 AND 42 KT...RESPECTIVELY. THE INITIAL INTENSITY IS
LOWERED TO 50 KT FOR THIS ADVISORY...WHICH COULD BE GENEROUS.

But Venezuela isn't even close to 15 N line? Was the area south of 15 N Venezuelan air space? Snowden mess must be worse than one would thought...
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Quoting 1455. GTstormChaserCaleb:
Wait what air space restriction from who?

HOWEVER...AIR SPACE
RESTRICTIONS PREVENTED THE PLANE FROM SAMPLING THE AREA FARTHER
SOUTH.


Aliens!
Member Since: Posts: Comments:
Quoting 1445. stormwatcherCI:
Check the co-ordinates from 8:00

Thats what i posted if I'm not wrong below 11 pm ones
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1465. Patrap
Gulf Of Mexico - Rainbow Loop

click image for Loop

Click fronts to see the Trof.


ZOOM by clicking on moving loop

Member Since: July 3, 2005 Posts: 426 Comments: 128654
1464. Dakster
11pm Important note about track:

BASED ON AVAILABLE
AIRCRAFT DATA THE CENTER IS RELOCATED A BIT TO THE SOUTH RELATIVE
TO THE PREVIOUS TRACK...WHICH HAS A RESULTED IN SOUTHWARD AND
WESTWARD SHIFT OF THE FORECAST TRACK THROUGH 36 HOURS. A STRONG
SUBTROPICAL RIDGE GUIDING CHANTAL RAPIDLY WEST-NORTHWESTWARD IS
FORECAST TO WEAKEN AND SHIFT EASTWARD AS A PRONOUNCED WEAKNESS
DEVELOPS ALONG THE UNITED STATES EAST COAST AND EXTENDS SOUTHWARD
INTO FLORIDA. THIS SHOULD RESULT IN THE TRACK OF CHANTAL BENDING
NORTHWESTWARD AND THEN NORTHWARD AFTER 36 HOURS. THE OFFICIAL
TRACK FORECAST LEANS ON THE WEAKER GFS SOLUTION WHICH HAS A
SHALLOWER CYCLONE BEYOND 48 HOURS.
Member Since: Posts: Comments:
ABSENT RELIABLE CENTER FIXES...THE SPEEDY INITIAL MOTION ESTIMATE...
285/25...OF CHANTAL IS QUITE UNCERTAIN. BASED ON AVAILABLE
AIRCRAFT DATA THE CENTER IS RELOCATED A BIT TO THE SOUTH RELATIVE
TO THE PREVIOUS TRACK...WHICH HAS A RESULTED IN SOUTHWARD AND
WESTWARD SHIFT OF THE FORECAST TRACK THROUGH 36 HOURS. A STRONG
SUBTROPICAL RIDGE GUIDING CHANTAL RAPIDLY WEST-NORTHWESTWARD IS
FORECAST TO WEAKEN AND SHIFT EASTWARD AS A PRONOUNCED WEAKNESS
DEVELOPS ALONG THE UNITED STATES EAST COAST AND EXTENDS SOUTHWARD
INTO FLORIDA. THIS SHOULD RESULT IN THE TRACK OF CHANTAL BENDING
NORTHWESTWARD AND THEN NORTHWARD AFTER 36 HOURS. THE OFFICIAL
TRACK FORECAST LEANS ON THE WEAKER GFS SOLUTION WHICH HAS A
SHALLOWER CYCLONE BEYOND 48 HOURS.

(Toot, Toot!)
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Quoting 1440. Stormchaser121:
LOL always seems to happen with every storm, never ceases to amaze me.
Member Since: Posts: Comments:
Quoting 1455. GTstormChaserCaleb:
Wait what air space restriction from who?

HOWEVER...AIR SPACE
RESTRICTIONS PREVENTED THE PLANE FROM SAMPLING THE AREA FARTHER
SOUTH.



That's a load of crap...they are not even near Venez
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Looks like we might loose Chantel by this time tomorow
Member Since: September 8, 2010 Posts: 0 Comments: 2209
Quoting 1447. Hurricane1956:
Very interesting from the 11:00Pm Discussion:
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.




the shorterm did some
Member Since: July 21, 2010 Posts: 0 Comments: 1177
Quoting 1447. Hurricane1956:
Very interesting from the 11:00Pm Discussion:
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.


That was from the 5 pm disco.
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Quoting 1432. cchsweatherman:
The latest discussion for Chantal explained why they never entered the southern part of the storm; apparently there are air space restrictions, so they could not cross 15 N.

What? where you make that up from? lol they can go anywhere into the carribean but can't violate certain countries airspace without permission...ex Cuba, Venez...
Member Since: Posts: Comments:
Wait what air space restriction from who?

HOWEVER...AIR SPACE
RESTRICTIONS PREVENTED THE PLANE FROM SAMPLING THE AREA FARTHER
SOUTH.
Member Since: Posts: Comments:
Quoting 1431. stormpetrol:

11:00 PM AST Tue Jul 9
Location: 15.3°N 66.2°W
Moving: WNW at 28 mph
Min pressure: 1009 mb
Max sustained: 60 mph

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 INCH, kinda dumbfounded here, movement still WNW, ???
LOCATION...15.4N 64.9W 8PM
11:00 PM AST Tue Jul 9
Location: 15.3°N 66.2°W


Looks west to me.
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1453. Patrap


http://www.ssd.noaa.gov/goes/east/gmex/flash-rb.h tml
Member Since: July 3, 2005 Posts: 426 Comments: 128654
Quoting 1446. MiamiHurricanes09:
Is that new? Never seen that happen before.
Nope.Depending on air traffic restrictions can happen.
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Quoting 1434. Hurricane12:
Let's hope DMAX works in Chantal's favor, or whatever is left of it, for that matter.


True I feel bamboozled , dazed & confused with what is going on I need a break from this storm for all I know it is causing a lot of pain to the Blog and the NHC.
Member Since: May 25, 2012 Posts: 0 Comments: 2043
Quoting 1438. Patrap:
Miami
NEXRAD Radar

Velocity Azimuth Display Wind Profile ° Elevation
Range 124 NMI



Radar close to the storm is the only way we're going to be able to figure this out.
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Chantal's circulation is pretty messed up, it looks like there's, two?

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Quoting 1424. scottsvb:
Chantal is on schedule.. a jog due west this evening, midlevel trough is causing sinking air on her NW side. Pressure is at 1009 that I posted 20 min ago but winds are a unreliable 60mph...more like 40-45mph. HH's left for the evening.

I agree I can not find any 60MPH winds.... But I also thing it moves to the west due to nontropical whatever Chantal.... I think the west movement because of strength.....
just my 2 cents worth and may not be worth that much....

Taco :o)
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Very interesting from the 11:00Pm Discussion:
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: Posts: Comments:
Quoting 1432. cchsweatherman:
The latest discussion for Chantal explained why they never entered the southern part of the storm; apparently there are air space restrictions, so they could not cross 15 N.
Is that new? Never seen that happen before.
Member Since: Posts: Comments:
Quoting 1431. stormpetrol:

11:00 PM AST Tue Jul 9
Location: 15.3°N 66.2°W
Moving: WNW at 28 mph
Min pressure: 1009 mb
Max sustained: 60 mph

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 INCH, kinda dumbfounded here, movement still WNW, ???
Check the co-ordinates from 8:00
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lol Recon had enough of looking Recon is almost home
Member Since: June 13, 2009 Posts: 2 Comments: 12151
Chantal has changed in appearance drastically in the last two hours. She may be weak in appearance still but yesterday HH took quite awhile in finding center and highest winds and many predicted she was a goner. Same could happen tonight if HH can get it together. As one of the most unique TS of all time, surely she's not going to just up and die on us. She's got some tricks left up her sleeves.
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SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...15.3N 66.2W
ABOUT 215 MI...345 KM S OF SAN JUAN PUERTO RICO
ABOUT 330 MI...530 KM SE OF SANTO DOMINGO DOMINICAN REPUBLIC
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 28 MPH...44 KM/H
MINIMUM CENTRAL PRESSURE...1009 MB...29.80 INCHES


That's some creative geometry to get 285 degrees heading out of what was in fact a net southerly motion...beats me how that works...
Member Since: January 25, 2012 Posts: 33 Comments: 1520
Interesting to read in the forecast discussion that the reason the new flare-up of convection was not sampled by the recon is because of airspace restrictions
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Member Since: September 2, 2011 Posts: 0 Comments: 1148
MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH...95 KM/H...WITH HIGHER
GUSTS. THESE WINDS ARE CONFINED TO A SMALL AREA TO THE EAST OF
THE CENTER.
LITTLE CHANGE IN STRENGTH IS EXPECTED BEFORE CHANTAL
REACHES HISPANIOLA...BUT WEAKENING IS FORECAST AFTER THAT TIME.

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1438. Patrap
Miami
NEXRAD Radar

Velocity Azimuth Display Wind Profile ° Elevation
Range 124 NMI

Member Since: July 3, 2005 Posts: 426 Comments: 128654


Did the ULL off of Florida "erode" all of the dry air surrounding it?
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I think the Recon instruments are malfunctioning we should just get some rest right now I am utterly speechless.
Member Since: May 25, 2012 Posts: 0 Comments: 2043

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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.