High wind shear disrupts Emily as it approaches Hispaniola

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

Share this Blog
26
+

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

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: 270 - 220

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 | 41Blog Index

270. 7544
look for a cone shift to west at 5pm imo maybe even a little south too
Member Since: Posts: Comments:
Quoting WarEagle8:
Glad to hear you are OK...what area are you in PR? I have vacationed in many areas of the beautiful island!

Near Corozal, but in Vega Alta. I'm surrounded in a beautiful forest and gorgeous scenery.
Member Since: Posts: Comments:
Vort has substantially increased.

Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
The NHC has Emily moving northwest immediatly. Do you really think that's plausible considering it's moving around 272˚ right now?

Considering that this system has followed the southern most track in the first NHC cone, it seems it could do the same this time. Weak system probably takes the Western part of that track. For that turn to happen , it should've started more WNW-NW now instead of a more W-WNW movement, and it hasn't. I expect a West shift in 5:00PM NHC Cone.
Member Since: Posts: Comments:
I see Emily as being influenced by blog conditions...which along with wind shear and dry air can greatly influence a tropical system. One contingent is rooting for a Texas landfall...one contingent is insisting on a GOM hit...and another contingent is sure of a South Florida impact. Emily is tearing herself apart trying to please all three. Maybe she coulda split into 2 storms, but I think 3 might be a little too much to ask.

Member Since: Posts: Comments:
Quoting Jedkins01:
Lucreto is just being a jerk, trying to start trouble. Don't feed his/her appetite for attention. That's what the main goal is for the immature and trouble makers. They just want to get negative attention and ruin other peoples day. Don't give in!


Member Since: July 6, 2010 Posts: 113 Comments: 32802
Quoting WeatherNerdPR:
Finally clearing up in my area...Seeing how my pool filled up, I got about 2-3 inches from Emily.



Glad you weathered it ok. I saw some of the pics from flooding. Not to nice looking at all.
Member Since: Posts: Comments:
Shear looks to be relaxing a bit around the center - may allow her to build convection... but shear is still quite strong just to the west so I doubt it stays gone for too long.
Member Since: Posts: Comments:
The US east coast not off the hook?.. this is giving me a headache

Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
The NHC has Emily moving northwest immediatly. Do you really think that's plausible considering it's moving around 272˚ right now?



They are hesitant to move the path because of the large swings the computer models have been having. I understand that, but come on! A slight westward is definitely warranted at this time.
Member Since: July 6, 2010 Posts: 113 Comments: 32802
Quoting WeatherNerdPR:
Emily putting her clothes back on:


LOL! Nevertheless, she is still dressed inappropriately and should not think of visiting Hispaniola in such attire.
Member Since: Posts: Comments:
2011 ACE
Arlene: 1.63
Bret: 2.95
Cindy: 1.84
Don: 1.50
Emily: 1.18(so far)
Total: 9.10(so far)
Member Since: Posts: Comments:
Quoting AWXWatcher:
GOES Latest water Vapor loop SEEMS to illustrate last minute restructuring. Any thoughts?

Link


Well shear is lifting, you can see it in the visible and also on CIMMS, if you click on past images, you can see wind shear go from 30 knots on top of Emily down to 20 knots. Can't wait to see an updated shear map, probably not for another hour or so.
Member Since: Posts: Comments:
/It's been forecast to turn north for days now.....
Female storms have a tendency to do what they like.
I'm cool with that, mind you!
Member Since: Posts: Comments:
Quoting WeatherNerdPR:
Finally clearing up in my area...Seeing how my pool filled up, I got about 2-3 inches from Emily.
Glad to hear you are OK...what area are you in PR? I have vacationed in many areas of the beautiful island!
Member Since: Posts: Comments:
Quoting Grothar:
GFDL




GFDL and HWRF are exited today for sure. Hopefully Emily doesn't end up being one of the "Shy, Silent Type".
Member Since: Posts: Comments:
Quoting PcolaDan:
Yep, winds definitely coming out of the.....no, wait, coming from the......or is that from.....never mind.



Lol, Dan!!
Member Since: Posts: Comments:
Lucreto is just being a jerk, trying to start trouble. Don't feed his/her appetite for attention. That's what the main goal is for the immature and trouble makers. They just want to get negative attention and ruin other peoples day. Don't give in!
Member Since: Posts: Comments:
Oh boy, is it time for me to take a picture without my shirt on yet.

:|
----

Anyways, one can clearly see the location of the trough on the 200 mb. vorticity map from CIMSS.

Member Since: July 6, 2010 Posts: 113 Comments: 32802
Time: 17:50:00Z
Coordinates: 17.7167N 69.3833W
Acft. Static Air Press: 843.2 mb (~ 24.90 inHg)
Acft. Geopotential Hgt: 1,569 meters (~ 5,148 feet)
Extrap. Sfc. Press: 1009.6 mb (~ 29.81 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 144° at 32 knots (From the SE at ~ 36.8 mph)
Air Temp: 18.1°C (~ 64.6°F)
Dew Pt: 8.2°C (~ 46.8°F)
Peak (10s) Flt. Lvl. Wind: 33 knots (~ 37.9 mph)
SFMR Peak (10s) Sfc. Wind: 40 knots* (~ 46.0 mph*)
SFMR Rain Rate: 0 mm/hr* (~ 0 in/hr*)
(*) Denotes suspect data
Member Since: July 14, 2009 Posts: 0 Comments: 3029
Soooooo
did the navigator nod off

Member Since: Posts: Comments:
Looks like she is trying to stay alive, i agree with most that the trach wills shift more to the left(West).

Could she be creating her own enviroment?
Member Since: Posts: Comments:
Quoting djboca:
Right now, Emily is tilting to the east. This is bad news, and something that Emily will have to work hard at recovering from.

Bad news? Are you seriously "championing" a storm that may cause death and destruction? Can you PLEASE keep your comments limited to facts and restrict your opinions to weather predictions while avoiding "scare tactics" (ie: worst summer, worst this, worst that) and "cheering" for storms?

This type of blogging by an intelligent and respected scientist is getting to be as bad as our national politicians' behavior.

Good Grief!!!!
Quoting quante:
2:00 p.m. NHC advisory not very bullish on Emily's future. Still moving west though, but forecast to turn NW this evening.

It's been forecast to turn north for days now.....
Female storms have a tendency to do what they like.
I'm cool with that, mind you!
Member Since: Posts: Comments:
240. 7544
i found this funny tho from the nhc

...EMILY STILL MOVING WESTWARD...APPEARS TO BE LESS ORGANIZED..... sounds like their are surpise she still moving west too lol
Member Since: Posts: Comments:
Time: 17:50:00Z
Coordinates: 17.7167N 69.3833W
Acft. Static Air Press: 843.2 mb (~ 24.90 inHg)
Acft. Geopotential Hgt: 1,569 meters (~ 5,148 feet)
Extrap. Sfc. Press: 1009.6 mb (~ 29.81 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 144° at 32 knots (From the SE at ~ 36.8 mph)
Air Temp: 18.1°C (~ 64.6°F)
Dew Pt: 8.2°C (~ 46.8°F)
Peak (10s) Flt. Lvl. Wind: 33 knots (~ 37.9 mph)
SFMR Peak (10s) Sfc. Wind: 40 knots* (~ 46.0 mph*)
SFMR Rain Rate: 0 mm/hr* (~ 0 in/hr*)
(*) Denotes suspect data
Member Since: July 14, 2009 Posts: 0 Comments: 3029
Member Since: Posts: Comments:
Quoting patrikdude2:
Yeah, but this would mean rapid intensification around the Bahamas waters, this is unlikely in my opinion but this system has been too unpredictable ,lol. We will wait and see what it does.
Yea, I've never seen a tropical system this weird before.
Member Since: Posts: Comments:
The NHC has Emily moving northwest immediatly. Do you really think that's plausible considering it's moving around 272˚ right now?

Member Since: Posts: Comments:
GOES Latest water Vapor loop SEEMS to illustrate last minute restructuring. Any thoughts?

Link
Member Since: Posts: Comments:
Quoting lucreto:


You are absolutely right, about the land friction effect, winds also further drop due to various exposures (forested, and urban)

This pdf will be the last thing I say on the subject because it appears I have rubbed some people the wrong way.


Link


A report on the damage to manufactured homes does not mean that the ONLY significant damage was to manufactured homes. *bzzt* Thanks for playing.
Member Since: Posts: Comments:
Finally clearing up in my area...Seeing how my pool filled up, I got about 2-3 inches from Emily.
Member Since: Posts: Comments:
Quoting WeatherNerdPR:
Emily putting her clothes back on:
LOL !!
Member Since: Posts: Comments:
2:00 p.m. NHC advisory not very bullish on Emily's future. Still moving west though, but forecast to turn NW this evening.
Member Since: Posts: Comments:
Quoting reedzone:
You see good storms like Gustav (2008), Ernesto (2006), and Jeanne (2004) get ripped apart by going over Haiti.. However weak storms like Fay (2008)survive hard trips.. I got my eye on Emily, especially if she shoots the gap, not much weakening there, unless shear continues on but there are signs that shear is weakening, according to the CIMMS map, wind shear is lifting out.


I don't see Emily shooting the gap, I see Emily making landfall in and crossing over Cuba.
Member Since: Posts: Comments:
Yep, winds definitely coming out of the.....no, wait, coming from the......or is that from.....never mind.

Member Since: Posts: Comments:
Recon approaching Emily.

For those who would like to follow along...

Link
Member Since: Posts: Comments:
so, even the NHC says "IF"???

ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM

TROPICAL STORM EMILY DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052011
1100 AM AST WED AUG 03 2011

SATELLITE IMAGES INDICATE THAT EMILY HAS NOT BECOME ANY BETTER
ORGANIZED SINCE THE RECONNAISSANCE PLANE DEPARTED EARLIER THIS
MORNING. IN FACT...THE LOW-LEVEL CENTER HAS BECOME EXPOSED AND IS
LOCATED TO THE WEST OF THE CONVECTION DUE TO WIND SHEAR. THE LOW
LEVEL CIRCULATION IS ALSO LESS DEFINED THAN YESTERDAY. THE LAST
WINDS REPORTED BY THE RECONNAISSANCE PLANE WHILE EXITING THE
CYCLONE SUPPORT AN INITIAL INTENSITY OF 45 KNOTS...BUT THESE WINDS
ARE CONFINED TO THE NORTH AND EAST OF THE CENTER. GIVEN THE CURRENT
SHEAR PATTERN NO CHANGE IN INTENSITY IS EXPECTED BEFORE THE CENTER
MOVES OVER WESTERN HISPANIOLA TONIGHT. THEREAFTER...WEAKENING IS
ANTICIPATED WHILE THE CIRCULATION INTERACTS WITH THE HIGH TERRAIN
OF HISPANIOLA AND EASTERN CUBA. IF THE CYCLONE SURVIVES THE NEXT
DAY OR TWO...UPPER LEVEL WINDS ARE EXPECTED TO BE A LITTLE MORE
FAVORABLE FOR SOME STRENGTHENING AS EMILY MOVES NORTHWESTWARD
ACROSS THE BAHAMAS.


Thanks Angela, good remark you made...
Member Since: Posts: Comments:
225. Skyepony (Mod)
Emily is trying to fire from the center & cover up her circulation. I think she'll go just left of the next forecast point around the tip of DR that juts out to the south making landfall on Haiti.
Member Since: Posts: Comments:
Quoting Bluestorm5:
and 125 MPH winds offshore of North Carolina (where I live)? Wow... this is too extreme IMO.
Yeah, but this would mean rapid intensification around the Bahamas waters, this is unlikely in my opinion but this system has been too unpredictable ,lol. We will wait and see what it does.
Member Since: Posts: Comments:

Viewing: 270 - 220

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 | 41Blog 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
29 °F
Overcast

JeffMasters's Recent Photos

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