High wind shear disrupts Emily as it approaches Hispaniola

By: Dr. Jeff Masters , 5:06 PM GMT on August 03, 2011

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In defiance to its forecast, Tropical Storm Emily continues to move due west this morning, and we wonder just how far west it will get before turning toward Hispaniola. Recent Hurricane Hunter missions have shown that Emily is still very poorly organized, and although the center of circulation is plainly obvious on satellite imagery, it's only because it is so displaced from the thunderstorm activity. Wind shear around the storm is just high enough, around 20 knots out of the west, to push the upper levels of circulation and thunderstorm activity to the east, exposing the surface low. In order for tropical cyclones to intensify (or, continue to exist at all), they need to be vertically stacked and standing straight up in the atmosphere. Right now, Emily is tilting to the east. This is bad news for the organization of the storm, and something that Emily will have to work hard at recovering from. In addition to the wind shear, dry air continues to wrap around the north and west of the storm. This isn't as critical as unfavorable wind shear, but it's not helping to create new thunderstorm activity. The strongest winds of 50 mph were found to the north and east of the center this morning, and Emily is not expected to intensify before making landfall in Hispaniola, which is forecast for tonight. The HWRF is forecasting the strongest precipitation to fall on the northeast side of the storm as is passes over Hispaniola. This is relatively good news for Haiti, but the country could still receive up to 5 inches of rain, and since the models have been trending the track west over the past couple of runs, it's something to watch closely. No matter the scenario, Emily is expected to produce heavy rains, flash flooding, and mudslides in Haiti and the Dominican Republic, which are all to common on the mountainous island.


Figure 1. Forecast precipitation accumulation from the HWRF high resolution model's 6Z (2am EDT) run. The color contour scale is in inches. The coastlines are a thin, red line. The Dominican Republic is expected to get the most rain out of Emily. You can view the HWRF model runs on Wundermap.

Forecast for Tropical Storm Emily
The future of Emily remains uncertain, and even the National Hurricane Center is using the "if" word when forecasting Emily's track after crossing Hispaniola. "If" it makes it north of Hispaniola. Over the past couple of runs, the models have been trending their forecast tracks back to the west, most likely because Emily has remained on a westward track longer than expected. This is expected—the longer Emily remains shallow and unorganized, the longer it will track west. It will need to build up taller in the atmosphere to be influenced by the steering winds that can push it north. Given its westward track, today's models are likely closer to reality than what we've seen in the past couple of days. This morning, the CMC, UKMET, and HWRF models send Emily on a northwest track to Florida. This is a change from the past couple of days for the HWRF, but the CMC and UKMET have consistently been the western boundary of model consensus. THE GFDL has also taken a huge swing to the west, and now suggests it will come very close to a southeast Florida landfall. The ECMWF and GFS continue to forecast that Emily will take a harder turn north through the Bahamas, not reaching the Florida coast.


Figure 2. Satellite image of Tropical Storm Emily at 11:15am EDT. The surface circulation is visible to the west of the strongest thunderstorm activity.

Consensus of the models falls between the HWRF/GFDL solution and the ECMWF/GFS solution, and the National Hurricane Center continues to use the consensus for the official track forecast, which calls for Emily to take a turn to the northwest and make landfall in Hispaniola this afternoon, after which continuing northwest until Saturday morning when it's between the island of Grand Bahama and West Palm Beach, Florida. At this point, they expect the storm to jog north and then northeast.

Emily's intensity forecast continues highly dependent on the track it takes. Assuming it can survive the wrath of Hispaniola, Emily will enter slightly more favorable environmental conditions to the north of the islands. This is what the Hurricane Center is forecasting, although they remain cautious. There is a very good chance that, if Emily does turn northwest today, it will not be able to reorganize after crossing Hispaniola. If it does maintain organization, Emily could reach hurricane strength as it moves northeast out to the open Atlantic. The other scenario at this point is that the storm keeps moving west, which will be detrimental to its orgnization. The models that track Emily into the far eastern Gulf of Mexico don't suggest any reintensification—the CMC fizzles the system below tropical storm strength quickly, probably because of the long track over Cuba it would have to take. In any case, Emily remains a threat most certainly to Hispaniola, and potentially to Florida.

I'm planning a quick update later this afternoon/evening for an update on new model runs, and potential Hispaniola landfall.

Angela

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1003mb again on the sonde. Dropped in the eye.

000
UZNT13 KNHC 032015
XXAA 53208 99169 70705 04460 99003 27613 11502 00026 27612 11002
92716 23607 16507 85455 19856 08510 88999 77999
31313 09608 81954
61616 AF306 0805A EMILY OB 10
62626 EYE SPL 1687N07047W 1956 MBL WND 14004 AEV 20802 DLM WND 12
005 002843 WL150 11003 083 REL 1687N07047W 195437 SPG 1687N07047W
195622 =
XXBB 53208 99169 70705 04460 00003 27613 11864 20808 22850 19856
33843 19061
21212 00003 11502 11927 17007 22902 11004 33858 08509 44843 08512
31313 09608 81954
61616 AF306 0805A EMILY OB 10
62626 EYE SPL 1687N07047W 1956 MBL WND 14004 AEV 20802 DLM WND 12
005 002843 WL150 11003 083 REL 1687N07047W 195437 SPG 1687N07047W
195622 =
;
Member Since: Posts: Comments:
Quoting angiest:
Light Blue is XTRP, Dark Blue is TVCN, Brown is OFCL.

Meaning Emily has taken a more westerly course since this morning's coordinates.
Member Since: December 1, 2006 Posts: 2 Comments: 3623
Family in DR said the metro (subway/train) is closed down today, banks and other businesses are closed. To me thats a little too much for a tropical storm but i do understand the dangers that come from their terrible drainage system.
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In a past hour, TS Emily had moved 7 miles it look like from recon.
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Quoting Grothar:


I've been posting images since last night and no one has commented. They just don't care. :)



Grothar,Just wanted to let cha know you have people lurking in the back ground and we enjoy the images. Just I try not to talk to much cause especially lately I have asked a few questions and they NEVER get answered. the other day Tig did answer some of them. But I am glad to see alot of the regulars are back. When I first got back on some names didn't reconize. Glad to see Kman to.
What's ur take on Emily?
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Quoting hurricanejunky:
Emily moving well south of forecast points...
Click Here, turn on Trop Pts and follow the COC.
Look at the low level cloud motion in between the se tip of hispaniola and jamaica. It's moving to the south... hmmm lol
Member Since: December 1, 2006 Posts: 2 Comments: 3623
Quoting patrikdude2:




I see it now, I got it. Thanks to both of you :)


Anytime..
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Quoting PcolaDan:


Right above all the text links there is another link called "Graphics Archive"
Thanks !
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Time: 19:52:30Z
Coordinates: 16.75N 70.5W
Acft. Static Air Press: 842.9 mb (~ 24.89 inHg)
Acft. Geopotential Hgt: 1,539 meters (~ 5,049 feet)
Extrap. Sfc. Press: 1003.8 mb (~ 29.64 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 272° at 5 knots (From the W at ~ 5.8 mph)
Air Temp: 21.0°C (~ 69.8°F)
Dew Pt: 7.8°C (~ 46.0°F)
Peak (10s) Flt. Lvl. Wind: 5 knots (~ 5.8 mph)
SFMR Peak (10s) Sfc. Wind: 18 knots* (~ 20.7 mph*)
SFMR Rain Rate: 2 mm/hr* (~ 0.08 in/hr*)
(*) Denotes suspect data


I suspect this might be the lastest center fix, just a tad SW of the last fix.
Member Since: April 29, 2007 Posts: 0 Comments: 7922
Quoting BahaHurican:
Nah... the teacher was actually an American... lol


Can't have it all, I guess... hehe
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Light Blue is XTRP, Dark Blue is TVCN, Brown is OFCL.

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Emily moving well south of forecast points...
Click Here, turn on Trop Pts and follow the COC.
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Quoting FLWeatherFreak91:
A slowing storm can indicate that its initiating a turn, but to me, Emily looks to still be imbedded in ESE winds.


I was also noticing the same thing... winds on the north side of Cuba and just north of the Windward Passage are E-ESE. And in the Santo Domingo sounding, it was showing E winds at steering levels as well.
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Grothar: I knew I kept this for a reason!

http://www.hulu.com/watch/256933/the-view-viewtub e-the-psychic-twins
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Afternoon all...just wondering if a stall is in the cards? We'll see...
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Time: 19:52:00Z
Coordinates: 16.7333N 70.5167W
Acft. Static Air Press: 843.2 mb (~ 24.90 inHg)
Acft. Geopotential Hgt: 1,533 meters (~ 5,030 feet)
Extrap. Sfc. Press: 1003.9 mb (~ 29.65 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 286° at 4 knots (From the WNW at ~ 4.6 mph)
Air Temp: 20.7°C (~ 69.3°F)
Dew Pt: 7.8°C (~ 46.0°F)
Peak (10s) Flt. Lvl. Wind: 4 knots (~ 4.6 mph)
SFMR Peak (10s) Sfc. Wind: 18 knots (~ 20.7 mph)
SFMR Rain Rate: 0 mm/hr (~ 0 in/hr)
Member Since: April 29, 2007 Posts: 0 Comments: 7922
Quoting Cotillion:


And then he'd tell you to say 'apologise' after. ;)
Nah... the teacher was actually an American... lol
Member Since: October 25, 2005 Posts: 19 Comments: 22293
Floater loop showing a pop near the center,the ne convection more robust, and the se convection as well though a question as to whether circulation will fully draw it in. Also curious is the little 'thumb' of what would be lower level cloud moving into the center. Not convection per se, but better than clear open air. Does this all spell some beginning of success for this persistance to get together?
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787 It matters to many.
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cv wave looks like the real deal invest coming
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Time: 19:51:30Z
Coordinates: 16.7167N 70.5333W
Acft. Static Air Press: 843.2 mb (~ 24.90 inHg)
Acft. Geopotential Hgt: 1,533 meters (~ 5,030 feet)
Extrap. Sfc. Press: 1004.0 mb (~ 29.65 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 304° at 3 knots (From the WNW/NW at ~ 3.4 mph)
Air Temp: 20.6°C (~ 69.1°F)
Dew Pt: 7.8°C (~ 46.0°F)
Peak (10s) Flt. Lvl. Wind: 3 knots (~ 3.4 mph)
SFMR Peak (10s) Sfc. Wind: 17 knots (~ 19.5 mph)
SFMR Rain Rate: 0 mm/hr (~ 0 in/hr)
Member Since: April 29, 2007 Posts: 0 Comments: 7922
Weakening flag OFF for the last hour in the NOAA/SSD analysis: http://www.ssd.noaa.gov/PS/TROP/DATA/2011/adt/tex t/05L-list.txt
Member Since: August 16, 2007 Posts: 6 Comments: 12461
Quoting MiamiHurricanes09:
Oops, lol. You have to click on the cyclone you want, and at the top of the page it'll say "graphic archive".
Quoting ProgressivePulse:


Click the graphics archive button in the top header




I see it now, I got it. Thanks to both of you :)
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Quoting Grothar:


That's because you're nice, Baha!
But also because I've actually been looking... lol

Member Since: October 25, 2005 Posts: 19 Comments: 22293
Quoting Seflhurricane:
Still moving west just slowed down , may be an indication of a WNW turn ???
A slowing storm can indicate that its initiating a turn, but to me, Emily looks to still be imbedded in ESE winds.
Member Since: December 1, 2006 Posts: 2 Comments: 3623
Quoting BahaHurican:
So then the question is, not either, but both. Is it just the Bahamas, or FL too? Makes it clear what you really mean...

[I need to go find an old English teacher of mine and APOLOGIZE.... always used to tell us "say what you mean; pple can't read your mind". Now I appreciate how frustrated she must have felt.... lol]

Ah.... did find it unusual for them to stage from here... but, they dropped the 'sonde OVER Nassau???? [looks around] Wait... what's that whizzing sound I he-


lol



And then he'd tell you to say 'apologise' after. ;)
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Quoting Drakoen:



Just keeping everyone informed. I would give about the same percent as well.


Looks very good.

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Quoting KEEPEROFTHEGATE:
05L/TS/E
MARK
17.00N/70.33W
I will give her this...she is a persistant lil bugger!
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Still moving west just slowed down , may be an indication of a WNW turn ???
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Quoting starbuck02:
Where are the HH?


Flying north from the center. About to fly over Santo Domingo.
Member Since: December 1, 2006 Posts: 2 Comments: 3623
Quoting Stormridr911:


But, it is possible to have a Bahamian event without an ECFL event.
So then the question is, not either, but both. Is it just the Bahamas, or FL too? Makes it clear what you really mean...

[I need to go find an old English teacher of mine and APOLOGIZE.... always used to tell us "say what you mean; pple can't read your mind". Now I appreciate how frustrated she must have felt.... lol]

Quoting nrtiwlnvragn:


They left from Tampa, that was just the first dropsonde location.
Ah.... did find it unusual for them to stage from here... but, they dropped the 'sonde OVER Nassau???? [looks around] Wait... what's that whizzing sound I he-


lol

Member Since: October 25, 2005 Posts: 19 Comments: 22293
05L/TS/E
MARK
17.00N/70.33W
Member Since: July 15, 2006 Posts: 173 Comments: 54234
Quoting MiamiHurricanes09:
Emily is moving very slowly. Pressure just about the same.

195300 1647N 07029W 8433 01531 0038 +207 +078 285004 004 019 000 03


Yup, it looks like recon confirms a slower forward movement. Very slow, in fact.

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Quoting patrikdude2:
Thank you! but I still can't find the old forecast "CONE" graphic. I see all the archived text but not the forecast cone graphic. o_O


Right above all the text links there is another link called "Graphics Archive"
Member Since: August 22, 2008 Posts: 12 Comments: 6010
Where are the HH?
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Quoting ncstorm:
does the psychic twins prediction come to anyone's mind about the east coast storm?


No, but their yellow blouses ring a bell. Anyone keep a video of that?
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Quoting patrikdude2:
Thank you! but I still can't find the old forecast "CONE" graphic. I see all the archived text but not the forecast cone graphic. o_O


Click the graphics archive button in the top header
Member Since: Posts: Comments:
Quoting patrikdude2:
Thank you! but I still can't find the old forecast "CONE" graphic. I see all the archived text but not the forecast cone graphic. o_O
Oops, lol. You have to click on the cyclone you want, and at the top of the page it'll say "graphic archive".
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1003.8 mb
(~ 29.64 inHg)
Member Since: Posts: Comments:
Emily is moving very slowly. Pressure just about the same.

195300 1647N 07029W 8433 01531 0038 +207 +078 285004 004 019 000 03
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Advisory archive.
Thank you! but I still can't find the old forecast "CONE" graphic. I see all the archived text but not the forecast cone graphic. o_O
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Quoting yonzabam:


Drak, I know you know your stuff big time, but there's always a wave coming off Africa.

There was one a couple of days ago that was being called 'Franklin' on here. What happened to it?

Not saying that you shouldn't flag up waves coming off Africa. The one reason I don't put Jason on ignore is that he keeps us well informed about these waves with his images (thanks, Jason).

No idea what percentage of waves coming off Africa that are flagged up on here actually develop into tropical storms, but I'd intuitively put it at about 15%.

What would you put it at?


I read somewhere that about 100 waves a year come off Africa. I don't remember what century that was though. So your figure is about right, maybe even a little less.
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Quoting ChrisDcat5Storm:



can i get a link to ur latest video plzzz


See my blog entry from this morning for the video
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Quoting Levi32:
The elongated trough southwest of Emily may actually help to preserve her low-level circulation as she passes south of Hispaniola (not over it). Since her main inflow is from the south, it isn't as much of an issue that the mountains of Hispaniola are blocking low-level inflow from the north. Sometimes this can starve storms, weak ones and hurricanes alike.



can i get a link to ur latest video plzzz
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Getting close center I think will be just a tad SW of the last fix
Member Since: April 29, 2007 Posts: 0 Comments: 7922
Quoting Levi32:
Emily appears to be slowing down within the last couple of hours. This could signal that her turn to the northwest may be coming soon.
I was just noticing that. The westward motion of the lower level clouds ahead of Emily has slowed in the past few frames of vis sat too.
Member Since: December 1, 2006 Posts: 2 Comments: 3623
The elongated trough southwest of Emily may actually help to preserve her low-level circulation as she passes south of Hispaniola (not over it). Since her main inflow is from the south, it isn't as much of an issue that the mountains of Hispaniola are blocking low-level inflow from the north. Sometimes this can starve storms, weak ones and hurricanes alike.
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Emily appears to be slowing down within the last couple of hours. This could signal that her turn to the northwest may be coming soon.
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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.