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Remnants of Emily Part II: 295 Miles SSE Of Cape Hatteras, NC


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The UKM is close but no cigar...must not be building a 594 decameter ridge anymore.

I'm surprised a large contingent of weenies haven't latched onto the 12Z CMC run.

With that said, it will be interesting to see how the evolution of Emily prior to interacting with Hispañola compares with what the GFS and Euro are showing. If she doesn't get as well organized, will the trough be able to pick her up as well?

This forecast is tough cookies. I certainly can't wait to get more GIV data.

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Why is that?

A developed cyclone is literally a heat engine. It evaporates warm ocean water, and dumps the heat into the upper atmosphere. They exist to move heat from the tropics towards the poles. As the circulation approaches first land, and then high rugged mountains, the engine is disrupted. This is like pinching off the fuel line in a car. Winds approach the peaks, and are suddenly lifted, without having the opportunity to absorb any heat or moisture from the ocean. This sudden lift causes the moisture to be condensed out of the airmass and it falls as rain on the mountain (and later as mudslides or flash floods). The airmass now exists at a higher altitude devoid of moisture. (see orographic lifting). That same mechanism that causes the pacific NW to be so rainy, and the Great plains significantly drier, wreaks havoc on a developed cyclone.

A much less developed storm (open wave, weak disorganized circulation) doesn't have nearly as high cloud tops, or cold tops, or a defined circulation. It's convection doesn't rely on the circulation or the warm evaporating water/heat from the ocean. It's often fueled as t-storms in the afternoon in FL are - via surface convergence and instability. While its not "great" for it (going over mountains), it certainly isn't like pulling the plug.

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The thing that I find interesting is that Emily made it to the Caribbean Sea. Last year Tropical Storm Colin turned northwest before making it to the Caribbean. In fact, Danielle, Earl, Fiona, Igor, Julia and Lisa all made northwesterly or northerly turns before they reached the islands. Tropical Storms Alex and Gaston are the only two storms originating from Africa before September 20 that made it to the Caribbean. I understand 2010 and 2011 are two totally different seasons. However, I'm kinda wondering to myself if Emily is implying something concerning future African tropical waves this season.

2010 Season Animation

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The thing that I find interesting is that Emily made it to the Caribbean Sea. Last year Tropical Storm Colin turned northwest before making it to the Caribbean. In fact, Danielle, Earl, Fiona, Igor, Julia and Lisa all made northwesterly or northerly turns before they reached the islands. Tropical Storms Alex and Gaston are the only two storms originating from Africa before September 20 that made it to the Caribbean. I understand 2010 and 2011 are two totally different seasons. However, I'm kinda wondering to myself if Emily is implying something concerning future African tropical waves this season.

2010 Season Animation

That they will crash into Hispaniola and then recurve? I sure hope not.

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The thing that I find interesting is that Emily made it to the Caribbean Sea. Last year Tropical Storm Colin turned northwest before making it to the Caribbean. In fact, Danielle, Earl, Fiona, Igor, Julia and Lisa all made northwesterly or northerly turns before they reached the islands. Tropical Storms Alex and Gaston are the only two storms originating from Africa before September 20 that made it to the Caribbean. I understand 2010 and 2011 are two totally different seasons. However, I'm kinda wondering to myself if Emily is implying something concerning future African tropical waves this season.

2010 Season Animation

One big difference is sea surface temp anomalies. Last year we saw many African waves become cyclones early on as the higher SST anomalies were right off the W African Coast. This season those anomalous warm waters (around 1.5) exist E of the Caribbean Islands into the MDR and not off Africa. The placement of the Azores Ridge is different as well. The Euro seasonal continues to advertise a more W Bermuda High as well.

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One big difference is sea surface temp anomalies. Last year we saw many African waves become cyclones early on as the higher SST anomalies were right off the W African Coast. This season those anomalous warm waters exist E of the Caribbean Islands into the MDR (around 1.5) and not off Africa. The placement of the Azores Ridge is different as well. The Euro seasonal continues to advertise a more W Bermuda High as well.

Have I mentioned I've seen several ensemble runs indicating a neutral or even weakly positive NAO mid month?

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No offense, but then you haven't been doing this very long. And a lot of them that behave like this seem to be in the eastern Caribbean - there's a reason why it's called the Graveyard.

Still as I said earlier, it does look better on satellite than it did, and that is better than it looking worse. It seems like the models are hinting at a more favorable environment once it clears the islands, and to be honest it seems like systems do better after Hispaniola if they don't have really well developed inner core versus if they do.

I am well aware of the climatological desert of the eastern Caribbean. The famous John Hope rule applies here and with various factors of TUTT as well has the Venezuelan heat flow into the area climatologically speaking. That being said I still think that it is one of the more impressive visual presentation I've seen from a developing tropical system in this region. The Outflow is great, the CDO is going well with new bursts measuring to -75°C on IR. Given any other area of the Atlantic tropics one would assume it might be a borderline hurricane. I'm just baffled by the fact that there is so much convergence to produce the necessary lift for all of these thunderstorms in the mid-levels that there is a very weak westerly flow on the southern side on the surface, so much so that it might even be considered a open wave if it decreased even by 10 kts. I realize I have been only following the tropics for a few years but I do not ever remember such a impressive satellite presentation with a crappy surface presentation.

Edit: Don was sheared and its surface circulation disconnected the vast majority of the time. Emily's LLC is sitting directly under the main convection plumes, yet just looking at the surface (or near surface) you would think it wouldn't be.

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I was going to save this for a storm that got North of 30º that had a shadow of a doubt on the certainty of a fish storm, the 25º water to Northern New Jersey, but I can't restrain my joy.

Yeah, Water temperatures are roasting this year. It is pretty impressive.

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I was going to save this for a storm that got North of 30º that had a shadow of a doubt on the certainty of a fish storm, the 25º water to Northern New Jersey, but I can't restrain my joy.

20.jpg

The Potomac is near 90 around here. If we could get one up the channel right we could be in business. I'm hoping for an Isabel redux but stronger.

/sorry, shouldnt have gone there but I can't help myself sometimes.

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The Potomac is near 90 around here. If we could get one up the channel right we could be in business. I'm hoping for an Isabel redux but stronger.

/sorry, shouldnt have gone there but I can't help myself sometimes.

That's alright. Josh has been scoping out Matagorda Bay for a Carla 50th reunion/reduex come September...;)

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That's alright. Josh has been scoping out Matagorda Bay for a Carla 50th reunion/reduex come September...;)

Ummm, that's so not cool. Can you tell Josh to go scope out some other place for September? Ain't this the 20th anniversary of 1991's Hurricane Bob? Maybe he can go scope out a few bays up there in that region.

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I mentioned this is a few days back, but despite the 5pm NHC track showing a track that looks to be heading up the Eastern Seaboard, there is little to no chance that Emily will be able to go up the coast. The mid-level ridge steering the system does not stretch far enough north to allow such a far northerly track, mainly because the-NAO has displaced an upper level ridge over Greenland, which in turn has displaced the upper level westerlies further south over the West Atlantic, forcing the ridge to be squashed. This is why the models are becoming more adamant that Emily will sharply re-curve in the day 5-6 period as a new weakness opens up due to a weak upper level trough.

2wltv6p.png

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A developed cyclone is literally a heat engine. It evaporates warm ocean water, and dumps the heat into the upper atmosphere. They exist to move heat from the tropics towards the poles. As the circulation approaches first land, and then high rugged mountains, the engine is disrupted. This is like pinching off the fuel line in a car. Winds approach the peaks, and are suddenly lifted, without having the opportunity to absorb any heat or moisture from the ocean. This sudden lift causes the moisture to be condensed out of the airmass and it falls as rain on the mountain (and later as mudslides or flash floods). The airmass now exists at a higher altitude devoid of moisture. (see orographic lifting). That same mechanism that causes the pacific NW to be so rainy, and the Great plains significantly drier, wreaks havoc on a developed cyclone.

A much less developed storm (open wave, weak disorganized circulation) doesn't have nearly as high cloud tops, or cold tops, or a defined circulation. It's convection doesn't rely on the circulation or the warm evaporating water/heat from the ocean. It's often fueled as t-storms in the afternoon in FL are - via surface convergence and instability. While its not "great" for it (going over mountains), it certainly isn't like pulling the plug.

Nice explanation. Thanks.

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We might be getting ready to see a bit of a bought of intensification over the next several hours...and here's why.

First off, as Phil pointed out, radar is finally showing some signs of curved banding developing near or with Emily's center of circulation:

post-525-0-15975700-1312323357.gif

In addition, it appears as though Emily slowing down has allowed the upper level anti-cyclone to move back over top of the system. This is allowing for weak easterly winds aloft as opposed to northerly or westerly winds that would cause wind shear due to the fast low level easterly flow. This may allow convection to wrap all the way around Emily's western semi-circle, assuming dry air can stay out:

post-525-0-65166100-1312323552.gif

Outflow is well developed also, especially in the northern quadrants.

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