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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1070. wpb
bill gray

total year 15
hurricanes 9
major 5

issued today
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The Center is nearly one degree off the next forecast point, probably 50 miles or can make a lot difference in where a storm goes,tomorrow should be an interesting day with Emily.
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1067. nash28
Hey Press!

Hot enough for ya? Hitting 100 here today. Hotter than Lucifers rear end!
Member Since: July 11, 2005 Posts: 190 Comments: 16972
Quoting BahaHurican:
I have to say, EPac has been churning them out like pats of butter...

BTW, how's Muifa doing?

Like so:
Member Since: Posts: Comments:
1065. Mucinex
Quoting nrtiwlnvragn:


Walt Cronise (I think thats the spelling)?

Geez, haven't heard that name in a looong time.
I was think more Don Noe and his weather rock.

Personally, I trust the ghost of Weaver the WeatherBird.
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Quoting GHOSTY1:
alright who gave me a plus 1 for saying i was a really sensitive land mine cause i wasn't expecting that :P


Probably the same person who gave me a minus for being persnickity...LOL!
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That new cone is laughable.
Member Since: September 3, 2009 Posts: 0 Comments: 520
Quoting MississippiWx:


I haven't seen too much wobbling in track on visible. There may have been a slight jump to the north to get underneath convection, but the track is still basically due west.


Sorry I meant slowing down on those earlier center fixes.
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1061. SeaMule
this thing is a lot like Katrina....they kept saying what it would do....and it didn't. it tended west until it hit new orleans. the models have a biased towards turning.

I think the turn ain't a gonna happen till the GOM is clearly in her sights.....

we have a katrina on our hands.....it'll probably hook into Tampa Bay as a cat 4-5

imho
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As many have been observing for the last several days (knowing of the pending brush with Hispanola), we are still in a high degree of uncertainty until the Storm exits Haiti but notice the "smoother" track ride through the MONA passage and NHC keeps Her at TS status crossing Haiti. Not sure if this will pan out (no significant disruption of the very weak circulation) but what do I know. As far as South Florida/Bahamas, not time to put up the shutters yet but definitely a good time to stock up on some supplies and fill up your gas tanks as there will be a very small window to act on Friday if Emily survives the crossing intact and does intensify past TS.
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1059. ncstorm
Quoting stormpetrol:
A GRADUAL TURN TO THE
WEST-NORTHWEST AND NORTHWEST IS EXPECTED DURING THE NEXT DAY OR SO
.

Honestly, how many days now? I could be totally wrong, but Emily would have to turn NNW now just to encounter the mountains of Haiti alone.Man has become to dependent on machines, therefore not that he he doesn't have it in him, but common sense and old time forecasting sames to have taken a back seat( just my opinion)


this is another earl again..they kept saying that last year as well but it was northeast instead of northwest
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1058. GHOSTY1
this turn to the north and northeast is never coming they keep saying it but its not goin to happen, imo :)(really have no idea why i put a smiley but he's there and he wont leave)
Member Since: July 25, 2011 Posts: 0 Comments: 453
1057. BrandiQ
What I dont understand is that this forecast shows less land interaction but they still believe that it will stay a TS... does anyone know why?
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Although I was shocked about the track forecast not changing, the new discussion at least shows they are preparing to change the forecast significantly if necessary. They are just playing it safe. If the more westward motion continues overnight into tomorrow and the north turn does not materialize, I expect the official forecast to shift significantly left.
Member Since: August 21, 2008 Posts: 0 Comments: 7566
Quoting extreme236:
With all the wobbling Emily is doing one would think that a direction change is coming soon...maybe


I haven't seen too much wobbling in track on visible. There may have been a slight jump to the north to get underneath convection, but the track is still basically due west.
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Quoting Cotillion:


Certainly has an interesting eye. Has an annular check been run on it yet?

Looks like it's becoming Annular, as I said on the last page. This blog is moving too fast -_- I will likely drop off soon until later in the evening.
Member Since: July 29, 2006 Posts: 28 Comments: 1797
1053. angiest
Quoting AllStar17:
The cone is actually less in the United States than before. Confusing.


Six hours newer = smaller cone. They seem to have low confidence in the forecast at this point, but the size of the cone is deterministic and does not reflect the uncertainty in placing the TFP. It shows the average error that many hours from "now."
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Ok, the NHC acknowledges that Emily is continuing west...already west of their earlier tracks...yet still thinks she is going to suddenly make a hard right turn?? IMO, this is why some people wait so long to start their final preps for a storm. I say swallow the pride and move the tracks west if you can see that it's not following the original track.

I also agree with an earlier post...in that I don't understand why watches weren't issued for part of the ECFL (even if it's south of me...I'm on the Treasure Coast).
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Quoting AllStar17:
Doubts continue in the discussions.

AFTER THAT...THE OFFICIAL FORECAST STILL
ASSUMES THAT THE WESTERN ATLANTIC TROUGH WILL DEEPEN SUFFICIENTLY
TO TURN THE CYCLONE NORTHWESTWARD AND NORTHWARD. HOWEVER...IF THE
NORTHWARD TURN DOES NOT BEGIN SOON...THE THREAT TO THE SOUTHEASTERN
UNITED STATES WILL INCREASE.

Can someone please give a time for this trough? When is expected to be at its deepest and when is it expected to move out?
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1050. ncstorm
I took from the discussion that the threat would be to florida and northward if the turn happens later..hence the words southeastern united states..
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Quoting MiamiHurricanes09:
I was thinking Don Noe.


Some of us remember back farther..... when we can remember.
Member Since: September 23, 2005 Posts: 14 Comments: 11211
I assume ya'll read Avila's comments.... now that is a man not afraid to call a model a model...
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Quoting ChrisDcat5Storm:
...THE OFFICIAL FORECAST STILL
ASSUMES THAT THE WESTERN ATLANTIC TROUGH WILL DEEPEN SUFFICIENTLY
TO TURN THE CYCLONE NORTHWESTWARD AND NORTHWARD. HOWEVER...IF THE
NORTHWARD TURN DOES NOT BEGIN SOON...THE THREAT TO THE SOUTHEASTERN
UNITED STATES WILL INCREASE.

But, if it misses the trough the threat could also decrease if the storm moves WNW along the coast of, or over, Cuba (it would likely dissipate).
Member Since: July 29, 2006 Posts: 28 Comments: 1797
Quoting stormpetrol:
A GRADUAL TURN TO THE
WEST-NORTHWEST AND NORTHWEST IS EXPECTED DURING THE NEXT DAY OR SO.

Honestly, how many days now? I could be totally wrong, but Emily would have to turn NNW now just to encounter the mountains of Haiti alone.Man has become to dependent on machines, therefore not that he he doesn't have it in him, but common sense and old time forecasting sames to have taken a back seat( just my opinion)



man makes plans...and God laughs...
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1045. GHOSTY1
alright who gave me a plus 1 for saying i was a really sensitive land mine cause i wasn't expecting that :P
Member Since: July 25, 2011 Posts: 0 Comments: 453
Quoting reedzone:
Surprised watches weren't issued for South Florida.. Th Bahamas next to South Florida have watches.
more than likely watches will be issued for saouth florida tomorrow , but note if the westward motion continues you bet they will be issued its a 50/50 gamble right now
Member Since: July 14, 2009 Posts: 0 Comments: 3022
Quoting AllStar17:
Doubts continue in the discussions.

AFTER THAT...THE OFFICIAL FORECAST STILL
ASSUMES THAT THE WESTERN ATLANTIC TROUGH WILL DEEPEN SUFFICIENTLY
TO TURN THE CYCLONE NORTHWESTWARD AND NORTHWARD. HOWEVER...IF THE
NORTHWARD TURN DOES NOT BEGIN SOON...THE THREAT TO THE SOUTHEASTERN
UNITED STATES WILL INCREASE.
I just don't see Emily turning NW or N soon at all. I would think it'll go between Haiti/Cuba and through western side of The Bahamas. I think it'll shave Florida coastline, then make a brief landfall in South Carolina before curving out through SC/NC border and out.
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1042. nash28
Quoting AllStar17:
The cone is actually less in the United States than before. Confusing.


Per the discussion, the NHC is putting the weight behind the trough deepening enough to impart the turn away from the SE CONUS. Having said that, they are also correct in saying if Emily continues on this 280 degree heading much longer, the threat becomes more real for a possible landfalling system. If this verifies, you can bet the NHC will be on it and adjust accordingly.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
A GRADUAL TURN TO THE
WEST-NORTHWEST AND NORTHWEST IS EXPECTED DURING THE NEXT DAY OR SO.

Honestly, how many days now? I could be totally wrong, but Emily would have to turn NNW now just to encounter the mountains of Haiti alone.Man has become to dependent on machines, therefore not that he he doesn't have it in him, but common sense and old time forecasting sames to have taken a back seat( just my opinion)
Member Since: Posts: Comments:
1040. HadesGodWyvern (Mod)
RSMC Miami National Hurricane Center
Tropical Cyclone Advisory #15
SEVERE TROPICAL CYCLONE EUGENE (EP052011)
2:00 PM PDT August 3 2011
=====================================

SUBJECT: EUGENE Reaches Category Four Major Hurricane

At 18:00 PM UTC, Hurricane Eugene (942 hPa) located at 16.0N 115.4W or 520 NM southwest of southern tip of Baja California, Mexico has sustained winds of 120 knots with gusts of 145 knots. The cyclone is reported as moving west northwest at 12 knots.

Dvorak Intensity: T6.0

Hurricane Force Winds
======================
40 NM from the center

Gale Force Winds
================
135 NM from the center

Forecast and Intensity
======================
24 HRS: 17.4N 119.5W - 95 knots (Severe Tropical Cyclone/CAT 2)
48 HRS: 18.7N 124.2W - 60 knots (Tropical Cyclone)
72 HRS: 20.0N 128.5W - 40 knots (Tropical Cyclone)
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Cone shifted East slightly but the movement is still steadily west at 14mph. I thought if anything they would have left the cone untouched as the turn isn't happening yet.
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Quoting beell:


Ok. Thanks again. Liked the other flight plan better.
: -)


That was tomorrows
Member Since: September 23, 2005 Posts: 14 Comments: 11211
Regardless of the LLC, here comes the rain DR.

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With all the wobbling Emily is doing one would think that a direction change is coming soon...maybe
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1034. Skyepony (Mod)
Quoting Cotillion:


Certainly has an interesting eye. Has an annular check been run on it yet?



## ANNULAR HURRICANE INDEX (AHI) EP052011 EUGENE 08/03/11 12 UTC ##
## STORM NOT ANNULAR, SCREENING STEP FAILED, NPASS=6 NFAIL=1 ##
## AHI= 0 (AHI OF 100 IS BEST FIT TO ANN. STRUC., 1 IS MARGINAL, 0 IS NOT ANNULAR) ##
Member Since: August 10, 2005 Posts: 173 Comments: 38148
1033. GHOSTY1
Quoting Bluestorm5:
it was actually predicted to max out as Category 1.


i thought the wundeground was only predicting a minimal hurricane and when i gone and saw he strong he got i was shocked
Member Since: July 25, 2011 Posts: 0 Comments: 453
Quoting winter123:
Is Eugene trying to become annular? If that's the case, it will be going for a long time, even way out into cooler waters.

Edit: Should probably post this.
"An annular hurricane, also known as a truck tire or doughnut hurricane,[1] is a tropical cyclone in the Atlantic or Eastern Pacific Oceans that features a large, symmetric eye surrounded by a thick ring of intense convection. This type of storm is not prone to the fluctuations in intensity associated with eyewall replacement cycles, unlike typical intense tropical cyclones. Annular hurricanes also tend to persist, even when encountering environmental conditions which easily dissipate most other hurricanes." -Wikipedia
I have to say, EPac has been churning them out like pats of butter...

BTW, how's Muifa doing?

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Quoting GHOSTY1:
my bad hurricanejunky i just lost my cool again, you can probably tell i have a short fuse so if i go off be ready cause i do it quite a bit and i get over it. Sorry :P (more like a landmine, a really sensitive land mine)


No problem, I have my moments too!
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Link

Dvorak. You can clearly see upper and lower level flow. Lower level traveling north. Emily churning what looks to be due W.
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The NHC has been using some hesitant language in their forecasts with Emily.
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Rut Roh! Ch. 5 here in W. Palm is employing the tag team weatherman concept.... a sure sign that they're ready to get nuts here.... talking about possible watches going up for us tonight.
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These systems can and do do weird things! What would
the cone of uncertainty, and the donut of destruction
look like if she stays under the islands, and stays west? I hate this time of year, but I love watching
them grow and move!
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1026. ncstorm
Quoting AllStar17:
The cone is actually less in the United States than before. Confusing.


I know right..wouldnt you think after that discussion they would show the track error in the cone?
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1025. snotly
Well at least its not this Emily!

If it happened this year it would be quite an event, but in 2005 just one of the 'average' storms.

Link
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Quoting reedzone:
Surprised watches weren't issued for South Florida.. Th Bahamas next to South Florida have watches.


its all in the timing...48 hours for a watch to be posted
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Ouch when they start using the word ASSUME...
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Quoting nrtiwlnvragn:


Walt Cronise (I think thats the spelling)?
I was thinking Don Noe.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
That track change looks most conducive for Emily to intensify. About as good as it gets for a storm in this position.
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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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