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Atlantic Tropical Action 2014


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I think that this season is going to be more active than most other people anticipate, but that all the activity will be squeezed into a one-month period between mid-August and mid-September (before seasonal wavelengths amplify and the atmosphere responds to the weak Niño kicking in). The CV season will end by mid-September at the latest (prime time will be the last weak of August and the first weak of September). There will be no late season in the Caribbean in late September/October due to El Niño. So we will have little room for error in such a brief season. Everything needs to pick up and wind down on time, or else the season will be ruined. Really, even with the positive factors other people have mentioned, the best the U.S. can hope for is likely to be homegrown, frontal/baroclinic development around 30°-40°N off the East Coast or some homegrown action in the eastern Gulf. We could see another hurricane hitting the U.S., but the odds are against its occurrence (and I don't expect it), and a major hit is, to be frank, a wishcast this year.

 

The pickings should be much better in the EPAC and WPAC, especially with the ECMWF forecasting very low MLSPs in the EPAC by October (a classic set-up for big MX hits).

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Not sure why NHC is ignoring that easterly wave south of the CVs.  GFS has a TS in 36 h, and ECMWF sorta likes it too. 

 

Doesn't have much potential for longevity, but needs at least a lemon imo. 

Early, short-lived CV systems seem to face a higher bare in regard to sustenance of convection for a sufficient period of time. Middling systems farther W/closer to major land masses seem to be classified more readily than a better-organized system in the MDR. However, the GFS is usually too aggressive with early CV development, so I trust the ECMWF that nothing will materialize.

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Really surprised this wave has not been mentioned yet. Upper-level ridging is positioned in the East Atlantic, allowing for low wind shear. The wave has quite a bit of moisture with it despite an otherwise dry environment. Couple that with decent model support, and this should have the opportunity to become Bertha over the next 3 days.

 

Long-term prospects don't look good though; the wave/cyclone should interact with an upper-level trough in the central Atlantic in 4 days or so. Sea surface temperatures will be cooler too.

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Really surprised this wave has not been mentioned yet. Upper-level ridging is positioned in the East Atlantic, allowing for low wind shear. The wave has quite a bit of moisture with it despite an otherwise dry environment. Couple that with decent model support, and this should have the opportunity to become Bertha over the next 3 days.

 

Long-term prospects don't look good though; the wave/cyclone should interact with an upper-level trough in the central Atlantic in 4 days or so. Sea surface temperatures will be cooler too.

This is the same damned problem we've had the past several seasons--the sheared "graveyard" (predominant TUTT environment) in the central Atlantic between 40°-65°W just doesn't allow anything to survive. People focus on the stable air we've seen, but for CV development, shear has almost been as bad of a problem. The models posted earlier show lower shear in the MDR by late August than was present 2011-2013, but they show the lowest absolute shear in the Gulf/W Caribbean. My guess is that they're underdoing the shear in the MDR and that the TUTT will continue to play a big role this season, especially considering that everything (a relatively cooler Indian Ocean, a strong -PDO, and neutral-cool ENSO, etc.) was actually in favor of an active year last year, yet the shear was unusually high for a neutral-cool ENSO regime.

 

By the way, does anyone have a satellite link for the eastern MDR that updates frequently?

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This is the same damned problem we've had the past several seasons--the sheared "graveyard" (predominant TUTT environment) in the central Atlantic between 40°-65°W just doesn't allow anything to survive. People focus on the stable air we've seen, but for CV development, shear has almost been as bad of a problem. The models posted earlier show lower shear in the MDR by late August than was present 2011-2013, but they show the lowest absolute shear in the Gulf/W Caribbean. My guess is that they're underdoing the shear in the MDR and that the TUTT will continue to play a big role this season, especially considering that everything (a relatively cooler Indian Ocean, a strong -PDO, and neutral-cool ENSO, etc.) was actually in favor of an active year last year, yet the shear was unusually high for a neutral-cool ENSO regime.

 

By the way, does anyone have a satellite link for the eastern MDR that updates frequently?

I personally use this site: http://www.nrlmry.navy.mil/archdat/mediterranean/sahara/ir/

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By the way, does anyone have a satellite link for the eastern MDR that updates frequently?

 

You could always go with the tried and true NHC satellite page.

 

http://www.ssd.noaa.gov/goes/east/tatl/flash-avn.html

 

avn-animated.gif

 

----

 

The wave looks decently healthy tonight. The ECWMF has backed off on development, but the GFS still suggests this could become a TD/TS in the next 24-48 hours. Really the feature is still embedded in the ITCZ and it might take a bit more time for a closed circulation to evolve (though ITCZ breakdown of the vorticity strip into a discrete circular vortex) from the elongated monsoon trough.

 

The problem however is that as the system gains latitude, it will probably feel the impact of the stout low-level ridge to its north. What will likely rip the system apart is not a strong TUTT, but rather the rapid easterly low-level flow that is moving faster than the weaker easterly upper-level flow. This is the same mechanism that ripped apart Dorian (2013) as it pulled away from the monsoon trough. It also didn't help that the thermodynamic environment was marginal, and the net westerly VWS was easily able to advect the dry air into the core and squash any substantial convective activity. These same problems are present in the environment ahead of this disturbance.

 

That's really for beyond 48 hours. In the mean time, I agree with the consensus here that this is at least lemon worthy. 

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By the way, does anyone have a satellite link for the eastern MDR that updates frequently?

 

The wave looks decent for something in July. Hopefully this is a sign that things will kick up a bit starting early-mid August

 

Here are my favorite that most don't know about: 

http://tropic.ssec.wisc.edu/real-time/wavetrak/msg_hrd/vis_zoom_east/msghrd.html

http://wms.ssec.wisc.edu/

http://tropic.ssec.wisc.edu/real-time/wavetrak/msg_hrd/ir_zoom_east/msghrd.html

 

"Pouch guys" (My 2011 term) are back at it again BTW

 

http://www.met.nps.edu/~mtmontgo/storms2014.html

 

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Speaking of which:

 

GFS merges P03L and P04L together and makes something that may be worth watching...

SYNOPSIS 2014071900

P04L
13N, 12W
700 hPa

ECMWF:

GFS: Shifts from the north to south between 36 and 60 hours.  Hints at development soon thereafter, with P04L being the strongest pouch in the tropical Atlantic.

UKMET: Continues to tracks a bit more to the north than other models, eventually passing the STR axis, becoming stretched meridionally as it does so, and dissipating.  Note: UKMET depicts P03L to the west as stronger than P04L.

NAVGEM: Starts like GFS, with a merger of a northern and southern portion just west of Africa. (Yesterday, I tracked the southern portion as P03L being absorbed by P04L. Today, NAVGEM keeps another circulation intact farther west as P03L.)  NAVGEM then ends like UKMET, tracking P04L to the northwest and dissipating in the subtropical ridge.

 

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This is the same damned problem we've had the past several seasons--the sheared "graveyard" (predominant TUTT environment) in the central Atlantic between 40°-65°W just doesn't allow anything to survive. People focus on the stable air we've seen, but for CV development, shear has almost been as bad of a problem. The models posted earlier show lower shear in the MDR by late August than was present 2011-2013, but they show the lowest absolute shear in the Gulf/W Caribbean. My guess is that they're underdoing the shear in the MDR and that the TUTT will continue to play a big role this season, especially considering that everything (a relatively cooler Indian Ocean, a strong -PDO, and neutral-cool ENSO, etc.) was actually in favor of an active year last year, yet the shear was unusually high for a neutral-cool ENSO regime.

 

By the way, does anyone have a satellite link for the eastern MDR that updates frequently?

 

This is my favorite for the eastern MDR / Africa.

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Surprise...92L

Looks pretty good actually.

Unfortunately, it's going to get ripped apart by the fast low-level easterlies within the next day and a half and then degenerate into nothing by losing its low-level vorticity maximum. No reliable model shows a closed circulation by the time 92L enters the Lesser Antilles in three and a half days. The CMC does maintain an intact low that passes N of the Leeward Islands, but again, it's the CMC. For some reason, the early (12Z) intensity models, including the SHF5, are rather aggressive and show the system reaching hurricane intensity in five days…that seems dubious to me.

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Unfortunately, it's going to get ripped apart by the fast low-level easterlies within the next day and a half and then degenerate into nothing by losing its low-level vorticity maximum. No reliable model shows a closed circulation by the time 92L enters the Lesser Antilles in three and a half days. The CMC does maintain an intact low that passes N of the Leeward Islands, but again, it's the CMC. For some reason, the early (12Z) intensity models, including the SHF5, are rather aggressive and show the system reaching hurricane intensity in five days…that seems dubious to me.

Not only the easterlies, if it tries to gain any latitude, the subsidence will start to affect it.  You can see it in the satellite picture north of the system.

 

vis-animated.gif

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000
ABNT20 KNHC 211507
TWOAT

SPECIAL TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
1110 AM EDT MON JUL 21 2014

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Special outlook issued to update discussion of system in the
central tropical Atlantic.

Updated: Shower activity associated with a small area of low
pressure located about midway between the Cape Verde Islands and the
Lesser Antilles has increased a little during the past few hours.
Although this activity remains limited, it continues to show signs
of organization. Satellite data also indicate that a closed
circulation could be forming and that the system is producing a
small area of winds near tropical storm force. A tropical depression
could develop during the next couple of days while the system moves
westward to west-northwestward at 15 to 20 mph. After that time
however, environmental conditions are expected to become less
conducive for development. Interests in the Lesser Antilles should
monitor the progress of this system.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...50 percent.

 

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The 12Z GFS shows the favorable anticyclonic flow at 200 mb breaking down in the next few days as a TUTT to the NE of 92L undercuts the developing outflow channel and thereby imparts unfavorable northerly shear over the system while the low-level easterlies remain steady or strengthen. Plus, due to the TUTT, the low-level winds should back more to the ENE, allowing the stable air N of the circulation to get more entrained into the rest of 92L, thereby suppressing convection. Given the stable air nearby, the current improvement in organization should end later tonight and then reverse dramatically by tomorrow. 92L simply lacks the time and environment to develop sustained convection and thus warrant a TD/TS classification. A classification today would be premature and lead to some premature TS Watches for the islands, when in fact 92L will be destroyed by the time it gets there.

 

 

This is the same damned problem we've had the past several seasons--the sheared "graveyard" (predominant TUTT environment) in the central Atlantic between 40°-65°W just doesn't allow anything to survive. People focus on the stable air we've seen, but for CV development, shear has almost been as bad of a problem. The models posted earlier show lower shear in the MDR by late August than was present 2011-2013, but they show the lowest absolute shear in the Gulf/W Caribbean. My guess is that they're underdoing the shear in the MDR and that the TUTT will continue to play a big role this season, especially considering that everything (a relatively cooler Indian Ocean, a strong -PDO, and neutral-cool ENSO, etc.) was actually in favor of an active year last year, yet the shear was unusually high for a neutral-cool ENSO regime.

 

By the way, does anyone have a satellite link for the eastern MDR that updates frequently?

The TUTT pattern evolving on the GFS looks eerily reminiscent of that seen in the past several seasons, with one low after another dropping down between 40°-65°W and creating westerly shear. I hate to be repetitive, but I would take those forecasts for reduced shear with a HUGE grain of salt, especially considering that they're not consistent with other models' projections. I'm really skeptical that the CV season will amount to much. In fact, with so much shear, I'm even beginning to doubt that the rest of the basin will see much activity, at least south of 30° N.

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We have a cherry

 

000
ABNT20 KNHC 211724
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT MON JUL 21 2014

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Shower activity associated with a small area of low pressure located
about 1250 miles east of the Lesser Antilles has continued to
increase and show signs of organization during the past few hours.
Satellite data indicate that the circulation has become better
defined and the system is producing a small area of winds near
tropical storm force. Only a small increase in organization of the
shower activity would result in the formation of a tropical
depression as the system moves westward to west-northwestward at 15
to 20 mph during the next day or two.  After that time, however,
environmental conditions are expected to become less conducive for
development or strengthening. Interests in the Lesser Antilles
should monitor the progress of this system.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...70 percent

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Ascat from a few hours ago shows a small patch of 30+kts and west winds, but it's an incomplete scan of the circulation and it looks like it still needed a little work. Shear is very low, but environment is rather dry and thermodynamics are just so so, it's still alive just by the virtue that is feeding from the ITCZ's moisture. Even so, environment looks more favorable than not for further development next 24 hours.

 

Invest around 11N 43W

post-29-0-26484000-1405966156_thumb.gif

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Latest tropical guidance is rather optimistic on this becoming at least a high end TS.

I wouldn't believe it for a second. There have been cases when the statistical guidance has brought disturbances just like this all the way up to 120 knots, just to have the wave fizzle.

Once this splits from the ITCZ and loses most of its thermodynamic support, it should fall apart quickly.

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I wouldn't believe it for a second. There have been cases when the statistical guidance has brought disturbances just like this all the way up to 120 knots, just to have the wave fizzle.

Once this splits from the ITCZ and loses most of its thermodynamic support, it should fall apart quickly.

I agree that it has a limited window for development but it looks to be organizing rather quickly today and if it can obtain a stronger intensity early on it might be able to hang on longer.

 

The dry air, at least for now appears to be staying away to the north.

 

wv-animated.gif

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