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: 920 - 870

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

Muifa double eyewalls evident on radar: Link

(The linked image will be updated continuously.)
Member Since: August 16, 2007 Posts: 6 Comments: 12461
Quoting stormpetrol:


Think this track will pan out, personally I highly doubt it!


Me either. I think further west and not as sharp a turn.
Member Since: Posts: Comments:
Quoting BahaHurican:
Looks like they've dropped the first row of dropsondes [g-iv].


Indeed... now they're soon going to sample the area surrounding Emily.
Member Since: Posts: Comments:
Quoting angiest:


Don't trust the BAM's that far out. They are very simplistic and may not really know about the ridge.

oh yes they know about the ridge
Member Since: Posts: Comments:
Quoting msgambler:
Don't trust something that to this point has been almost spot on? How irresponsible!!!


Three key words in my post were "that," "far," and "out." In the short-term, they may be quite reliable, but based on the way those models work, they are probably overdoing the late term NW component.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting MiamiHurricanes09:
Yup. Lol.

Personally, John Morales of NBC 6 is the most knowledgeable and most calm out of everyone in south Florida. That's who I watch 99% of the time.


Gasp.... you don't watch Max?
Member Since: September 23, 2005 Posts: 14 Comments: 11163
Quoting whepton3:


that's west... everything moves in 90 degree increments... 90 east, 180 south, 270 west.

Bum dope. I move at 45°.
Member Since: Posts: Comments:
they moved the pages up to the top of the page? thank you!
Member Since: August 19, 2006 Posts: 13 Comments: 15288
Oh no! F5 key just broke! What a day and now I have to explain to the boss why in need a brand new computer! ;)
Member Since: Posts: Comments:


Think this track will pan out, personally I highly doubt it!
Member Since: April 29, 2007 Posts: 0 Comments: 7862
i thought the BAMM BAMS and BAMD were about right with Don and Arlene, i dont know about Bret and Cindy because i just didn't care about them they were fish storms, but imo i thought they were pretty darn accurate.
Member Since: July 25, 2011 Posts: 0 Comments: 453
1003.3 mb
(~ 29.63 inHg)


Is this the lowest pressure they have found?
Member Since: July 20, 2010 Posts: 0 Comments: 225
Looks like they've dropped the first row of dropsondes [g-iv].
Member Since: October 25, 2005 Posts: 19 Comments: 22101
Quoting MiamiHurricanes09:
Yup. Lol.

Personally, John Morales of NBC 6 is the most knowledgeable and most calm out of everyone in south Florida. That's who I watch 99% of the time.
Don't forget Local 10 , they have excellent coverage as well. Max Mayfield is there sometimes for "hurricane expert"
Member Since: July 20, 2010 Posts: 0 Comments: 225
Quoting midnightstorm:
Long time lurker, first time poster! Having seen
Katrina off the east coast of Florida before she
developed, raggedy, and un -certain, I never let
my guard down here in SE Louisiana!
Amen to that!!!!
Member Since: Posts: Comments:
Quoting Bluestorm5:
Hey, North Carolina need rains badly so this is good sign for people in Raleigh. I was wondering what's the chances of tropical storm force winds for Raleigh or is it 0% no matter what?


I think it was 5%.
Member Since: Posts: Comments:
The CMC shows Emily barely contacting the sw tip of Hispaniola, before running her into Eastern Cuba. Then the circulation reforms on the north coast of Cuba and continues wnw (over plenty of warm water) into the SE Gulf where it is caught by the weakness and sent into west central Florida.
Member Since: Posts: Comments:
Quoting angiest:


Don't trust the BAM's that far out. They are very simplistic and may not really know about the ridge.
Don't trust something that to this point has been almost spot on? How irresponsible!!!
Member Since: Posts: Comments:
Normally I don't even pay attention to the BAM models, but ironically they seem to the best grip on Emily. Because we are talking BAM I wouldn't follow their exact paths that's for sure LOL
Member Since: Posts: Comments:
Quoting WeafhermanNimmy:
Sorry!

Forecast gets more challenging on Sunday night through Tuesday as
tropical cyclone Emily will likely be approaching and then moving
parallel to the southeast coast. Track guidance keeps the system
offshore but brings the system within 200 miles or so of the
Carolina coast on Monday and Tuesday. There still is a good amount
of uncertainty with the track of Emily and even more uncertainty in
the intensity. If the system remains weak through the period expect
a track along the western envelope of guidance while a
stronger/deeper system should track further east.


Given a broad and modest upper level trough and a slightly
strengthening upper level jet over the northeast/middle Atlantic on
Monday...Emily should have her precipitation focused along and just
left of the track but still well offshore. Another player will be a
stalled cold front which should extend NE to SW along the eastern
Piedmont of Virginia and the Carolinas providing an good focus for
precipitation. The precipitation distribution across the eastern
Carolinas will be interesting as it is possible there will be a
minimum in precipitation along the coast in an area of short wave ridging
and lower precipitable water air between Emily and the approaching shortwave trough
from the northwest. For now will include low chance probability of precipitation for Monday
into Tuesday for much of central NC with best chance across the
southern/central coastal plain. High temperatures should continue to range
in the low and middle 90s.
Hey, North Carolina need rains badly so this is good sign for people in Raleigh. I was wondering what's the chances of tropical storm force winds for Raleigh or is it 0% no matter what?
Member Since: August 1, 2011 Posts: 28 Comments: 8009
896. Skyepony (Mod)
Member Since: Posts: Comments:
NHC track is essentially on top of the TVCN no reason to change track in the next update.
Member Since: Posts: Comments:
Product: Air Force Tropical RECCO Message (URNT11 KNHC)
Transmitted: 3rd day of the month at 20:27Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 306)
Storm Number: 05
Storm Name: Emily (flight in the North Atlantic basin)
Mission Number: 8
Observation Number: 12

Mandatory Data...

Observation Time: Wednesday, 20:24Z
Radar Capability: Yes
Aircraft Altitude: Below 10,000 meters
Coordinates: 17.4N 71.2W
Location: 109 miles (175 km) to the SE (137°) from Port-au-Prince, Haiti.
Turbulence: None
Conditions Along Flight Route: In the clear
Pressure Altitude: 1,520 meters
Flight Level Wind: From 40° at 26 knots (From the NE at ~ 29.9 mph)
- The above is a spot wind.
- Winds were obtained using doppler radar or inertial systems.
Flight Level Temperature: 18°C
Flight Level Dew Point: 7°C
Weather (within 30 nautical miles): Overcast / Undercast
850 mb Surface Altitude: 1,490 geopotential meters

Optional Data...

Estimated Surface Wind: From 60° at 35 knots (From the ENE at ~ 40.2 mph)
Member Since: April 29, 2007 Posts: 0 Comments: 7862
Quoting angiest:


Don't trust the BAM's that far out. They are very simplistic and may not really know about the ridge.



Dont the bamms always point to the GOM on every storm??
Member Since: August 19, 2006 Posts: 13 Comments: 15288
Quoting floodzonenc:
It is west :)  I am free to answer b/c I'm NOT hovering over the F5 key...  instead I will use mind control to get at least 4 of you to post it here on this very blog...  (commencing the mind control waves...)

;)



(trying to stop myself)......270 is west.....dammit!
Member Since: Posts: Comments:
im starting to believe im gonna to put money in that it will go into the gulf like the BAMM BAMS BAMD say, it seems that the arlene and don liked heading to the gulf so why wouldnt emily?
Member Since: July 25, 2011 Posts: 0 Comments: 453
Member Since: July 20, 2010 Posts: 0 Comments: 225
Quoting BahaHurican:
I am sooo relieved to find I am not the only one!!! I have basically abandoned 7 for wx anything.... on the basis of having to listen to this guy too much... Phil Ferro?
Yup. Lol.

Personally, John Morales of NBC 6 is the most knowledgeable and most calm out of everyone in south Florida. That's who I watch 99% of the time.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Long time lurker, first time poster! Having seen
Katrina off the east coast of Florida before she
developed, raggedy, and un -certain, I never let
my guard down here in SE Louisiana!
Member Since: Posts: Comments:
Quoting GHOSTY1:
So it looks like now the BAMM BAMD BAMS models all show Emily going into the GOM thats nice to know, i thought there was a high in the GOM supposed to prevent this but from these models is shows little to know opposition, am i looking at inaccurate models or old?


Don't trust the BAM's that far out. They are very simplistic and may not really know about the ridge.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting TropicalAnalystwx13:


No, most of ours broke a couple of days ago.

xD
LOL!!
Member Since: July 20, 2010 Posts: 0 Comments: 225
See how much it will change.


Member Since: Posts: Comments:
Quoting GHOSTY1:
So it looks like now the BAMM BAMD BAMS models all show Emily going into the GOM thats nice to know, i thought there was a high in the GOM supposed to prevent this but from these models is shows little to know opposition, am i looking at inaccurate models or old?
You are looking at the best of the best when it comes to modeling upper level dynamics.
Member Since: Posts: Comments:
Quoting hurricanejunky:


If I'm reading that map right, it looks like the weakness shifted west to over Florida...is that correct?


That is already 1-2 hours old, I think.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
So it looks like now the BAMM BAMD BAMS models all show Emily going into the GOM thats nice to know, i thought there was a high in the GOM supposed to prevent this but from these models is shows little to know opposition, am i looking at inaccurate models or old?
Member Since: July 25, 2011 Posts: 0 Comments: 453
Quoting hurricanejunky:


If I'm reading that map right, it looks like the weakness shifted west to over Florida...is that correct?


Bahamas into E FL region.
Member Since: Posts: Comments:
Quoting iamajeepmom:


Oh noooo....I can't stand the voice of the HEAD weather dude (nasally like) ... will NOT be watching that channel :)
I am sooo relieved to find I am not the only one!!! I have basically abandoned 7 for wx anything.... on the basis of having to listen to this guy too much... Phil Ferro?
Member Since: October 25, 2005 Posts: 19 Comments: 22101

Quoting beell:
Most recent outbound (north) leg from the center fix of the Air Force recon flying along on a static pressure surface of around 842mb. A 42 meter height increase at the same pressure level from near the last center fix to the north of the center before turning west.

A distance of about 60nm. Pretty decent increase. If there is a weakness to the north of Emily at this level recon is not finding it.

Over a
Great observation beell
Member Since: Posts: Comments:
Quoting catastropheadjuster:


what's 270 degrees? I have forgotten is that west or wnw or nw? I am sorry for all the questions.

sheri

West.
Member Since: Posts: Comments:
Very slow as indicated.

Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Not yet, but if and when watches get issued for our area you best believe they'll send the entire News Team to every Wal-Mart, Publix, and Home Depot in all of south Florida.


thay used to have them on the cable system here in boca... but it has since been dropped. So disappointed I won't be able to watch team coverage of the hysteria.
Member Since: July 19, 2010 Posts: 0 Comments: 645
Quoting catastropheadjuster:


what's 270 degrees? I have forgotten is that west or wnw or nw? I am sorry for all the questions.

sheri



Of subject
Saraland, Alabama 104.9 degrees don't know what the heat index is. I know when it was 96 heat index was 113 degrees.

but at our shop the temp is 107.6 u walk out there and it takes ur breath a way. so hubby sent me in the office. Having a hard time breathing.

sheri
Member Since: Posts: Comments:
Sorry!

Forecast gets more challenging on Sunday night through Tuesday as
tropical cyclone Emily will likely be approaching and then moving
parallel to the southeast coast. Track guidance keeps the system
offshore but brings the system within 200 miles or so of the
Carolina coast on Monday and Tuesday. There still is a good amount
of uncertainty with the track of Emily and even more uncertainty in
the intensity. If the system remains weak through the period expect
a track along the western envelope of guidance while a
stronger/deeper system should track further east.


Given a broad and modest upper level trough and a slightly
strengthening upper level jet over the northeast/middle Atlantic on
Monday...Emily should have her precipitation focused along and just
left of the track but still well offshore. Another player will be a
stalled cold front which should extend NE to SW along the eastern
Piedmont of Virginia and the Carolinas providing an good focus for
precipitation. The precipitation distribution across the eastern
Carolinas will be interesting as it is possible there will be a
minimum in precipitation along the coast in an area of short wave ridging
and lower precipitable water air between Emily and the approaching shortwave trough
from the northwest. For now will include low chance probability of precipitation for Monday
into Tuesday for much of central NC with best chance across the
southern/central coastal plain. High temperatures should continue to range
in the low and middle 90s.
Member Since: Posts: Comments:
Quoting RescueAFR:

Can't wait to see if Channel 7 starts 24 hour coverage..


They are working on their alliteration...Enigmnatic Emily, Elusive Emily...
Member Since: Posts: Comments:
Quoting CaneHunter031472:
I looks on Visible that it is starting to move NW or is it a wobble?

nope still moving W maybe its part of the convection that you are seeing
Member Since: Posts: Comments:
Quoting catastropheadjuster:


what's 270 degrees? I have forgotten is that west or wnw or nw? I am sorry for all the questions.

sheri


Due west. Just think of a full 360 degree turn. What is a 90 degree angle? If you start at 0 degrees and go to 90 degrees (clock-wise), it's due East. Obviously 0 degrees is due North. 180 degrees is due South, while 270 degrees is due West.
Member Since: July 15, 2006 Posts: 17 Comments: 10247

Viewing: 920 - 870

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

Mostly Cloudy
75 °F
Mostly Cloudy