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East Pacific invest thread


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Posted
  • Location: The Netherlands
  • Location: The Netherlands

This thread could be used to discuss tropical cyclone development in the 2014 Eastern Pacific (EPAC) hurricane season in general and individual tropical systems (up to and including invest formation).

 

El Nino

 

An El Nino is forecast to emerge in the summer/autumn of 2014 (the CPC indicates a more than 50% chance of an El Nino developing in the summer of 2014). An El Nino results on average in slightly enhanced hurricane activity in the EPAC. This is most likely a result of enhanced sea surface temperatures (SSTS) in the basin1,2. The SST anomalies during an El Nino can be seen below:

 

Posted Image

Average SST anomalies during an El Nino event (courtesy: NOAA).

 

Furthermore, an El Nino also decreases the average wind shear values over the Eastern Pacific, which is favourable for tropical cyclone development.3

 

First tropical development in the EPAC possibly already underway

 

There are signs that we might see tropical development as early as next week. This would be about 5-10 days before the official start of the season at May 15.4

 

The first sign comes from the Climate Prediction Center. They state that5:

 

Quote

 

 

Although prior to the start of the east Pacific hurricane season, some threat exists for tropical cyclone development off the coast of Central America and southern Mexico during Week-2. Both the GFS and CFS model guidance indicate this but the threat is considered low so early in the year and this will be re-evaluated next week. 

 

Of note is that this statement came from Tuesday April 29. Therefore, with week 2 the week from May 5 onward is meant.

 

Secondly, the GFS model shows a possible tropical cyclone developing near 10N, 106W. The forecasted cyclone is still quite far out (about 4 days at least), and therefore, confidence in this cyclone is rather low. The forecasted track of the possible cyclone is indicated below:

 

Posted Image

GFS forecast track of a possible tropical cyclone emerging as of May 6. (Courtesy: Florida State University)

 

What can be noted on the image above as well is that the SSTS are very favourable for development (29-30*C). 

 

The UKMET and CMC have also picked up the possible cyclone, but they do currently  very little with the cyclone. Some significant shifts in the track and intensity of the low are to be expected.

 

Hopefully this is a possible start of an exciting hurricane season!

 

Sources:

1:http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hurr/enso.rxml

2:http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

3:http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensofaq.shtml#HURRICANES

4:http://en.wikipedia.org/wiki/2014_Pacific_hurricane_season

5: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/ghazards/

http://moe.met.fsu.edu/cyclonephase/gfs/fcst/archive/14050212/106.html

Edited by Somerset Squall
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Posted
  • Location: Taunton, Somerset
  • Weather Preferences: Snow, thunder, strong winds
  • Location: Taunton, Somerset

Now been declared invest 90E. NHC have issued a special tropical dusturbance statement, indicating a medium chance, 30%, of tropical depression formation in the next 48hrs. Certainly a good looking disturbance, still broad but it's organising well in the currently low shear. How long the shear will stay low is open to question however.

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Posted
  • Location: Taunton, Somerset
  • Weather Preferences: Snow, thunder, strong winds
  • Location: Taunton, Somerset

Development chances have now been raised to 50% by NHC. An early appearance of Amanda looks more and more likely.

 

This rainbow loop shows the gradual organisation of 90E, and also that the invest is a very large disturbance:

 

Posted Image

Edited by Somerset Squall
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Posted
  • Location: Taunton, Somerset
  • Weather Preferences: Snow, thunder, strong winds
  • Location: Taunton, Somerset

Shear has displaced convection well northeast of the ill defined LLC of 90E. 90E is bringing very heavy rains to Mexico and will continue to do so over the next day or so. Development chances have been reduced to 20% by NHC however, due to the shear and land interaction.

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Is there an MJO wave anytime soon? I recall that spurred activity down the line last year.

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Posted
  • Location: Taunton, Somerset
  • Weather Preferences: Snow, thunder, strong winds
  • Location: Taunton, Somerset

600-800% abv nrml rainfall psbl in parts of Mexico this week as tropical system comes ashore. http://wxmaps.org/pix/prec3.html 

 

Blimey, that's likely to cause some dangerous mudslides and flooding for sure!

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Posted
  • Location: Taunton, Somerset
  • Weather Preferences: Snow, thunder, strong winds
  • Location: Taunton, Somerset

The East Pacific season has officially started as of today, but there are currently no disturbed areas to discuss after the dissipation of invest 90E.

 

From NHC:

 

TROPICAL WEATHER OUTLOOKNWS NATIONAL HURRICANE CENTER MIAMI FL1100 AM PDT THU MAY 15 2014For the eastern North Pacific...east of 140 degrees west longitude:Tropical cyclone formation is not expected during the next fivedays.Today marks the first day of the eastern North Pacific hurricaneseason, which will run until November 30.  Long-term averages forthe number of named storms, hurricanes, and major hurricanes are15, 8, and 4, respectively.The list of names for 2014 is as follows:Name           Pronunciation    Name            Pronunciation-------------------------------------------------------------Amanda         uh-MAN-duh       Marie           muh-REEBoris          bor-EES          Norbert         NOR-bertCristina       kris-TEE-nuh     Odile           oh-DEALDouglas        DUG-luss         Polo            POH-lohElida          ELL-ee-dah       Rachel          RAY-chullFausto         FOW-sto          Simon           SY-muhnGenevieve      jeh-nuh-VEEV     Trudy           TROO-deeHernan         her-NAHN         Vance           vanssIselle         ee-SELL          Winnie          WIN-eeJulio          HOO-lee-o        Xavier          ZAY-vee-urKarina         kur-REE-nuh      Yolanda         yo-LAHN-daLowell         LO-uhl           Zeke            zeekThis product, the Tropical Weather Outlook, briefly describessignificant areas of disturbed weather and their potential fortropical cyclone formation during the next five days.  Theissuance times of this product are 5 AM, 11 AM, 5 PM, and 11 PM PDT.After the change to standard time in November, the issuance timesare 4 AM, 10 AM, 4 PM, and 10 PM PST.A Special Tropical Weather Outlook will be issued to provideupdates, as necessary, in between the regularly scheduledTropical Weather Outlooks.  Special Tropical Weather Outlooks willbe issued under the same WMO and AWIPS headers as the regularTropical Weather Outlooks.A standard package of products, consisting of the Tropical CyclonePublic Advisory, the Forecast/Advisory, the Tropical CycloneDiscussion, and the Wind Speed Probabilities, is issued everysix hours for all ongoing tropical cyclones.  In addition, aSpecial Advisory package may be issued at any time to advise ofsignificant unexpected changes or to modify watches or warnings.The Tropical Cyclone Update is a brief statement to inform ofsignificant changes in a tropical cyclone or to post or cancelwatches or warnings.  It is used in lieu of or to precede theissuance of a Special Advisory.  The Tropical Cyclone Updates, whichcan be issued at any time, can be found under WMO header WTPZ61-65KNHC, and under AWIPS header MIATCUEP1-5.All National Hurricane Center text and graphical products areavailable on the web at http://www.hurricanes.gov. You can alsointeract with NHC on Facebook at https://www.facebook.com/NWSNHC.Notifications are available on Twitter when select NationalHurricane Center products are issued.  Information about our eastPacific Twitter feed is available athttp://www.hurricanes.gov/twitter.php.$$Forecaster Brown
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Posted
  • Location: The Netherlands
  • Location: The Netherlands

GFS 06z suggests TS development early next week. (Amanda) pic.twitter.com/6b2uGLnfkp

 

The NHC has also picked up the system:

 

 

 

1. An area of disturbed weather has formed several hundred miles south

of Acapulco Mexico. Environmental conditions could become a little

more conducive for development during the next few days while the

system moves westward to west-northwestward.

* Formation chance through 48 hours...low...10 percent

* Formation chance through 5 days...low...20 percent

 

Currently, a very weak circulation seems to exist within the invest, but it is poorly defined at best. Furthermore, convection is still scattered, indicating that this system will have a long way to go before it will be declared a tropical cyclone.

 

Posted Image

 

Source:

http://www.ssd.noaa.gov/PS/TROP/floaters/IN1/IN1_floater.html

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Posted
  • Location: Taunton, Somerset
  • Weather Preferences: Snow, thunder, strong winds
  • Location: Taunton, Somerset

The system has now been tagged invest 91E. The system is showing signs of slow organisation, but as Vorticity has said, it has a little way to go yet. However, conditions do look favourable. NHC have upped the chances for TC development to 40% in the next 48 hours and 60% in the next 5 days.

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Posted
  • Location: Taunton, Somerset
  • Weather Preferences: Snow, thunder, strong winds
  • Location: Taunton, Somerset

91E is still producing some vigorous convection but still lacks a well defined centre. NHC have dropped development chances to 20%, but state that development chances will increase if the centre reforms further east nearer the largest convective mass. Overall, still a very disorganised invest.

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Posted
  • Location: Tiree
  • Location: Tiree

91E 

 

All but gone

 

An elongated trough of low pressure located several hundred miles
south of the southern tip of the Baja California peninsula is
moving little. Associated shower activity has decreased
significantly this morning, and development of this system is
unlikely due to unfavorable environmental conditions.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...near 0 percent

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Posted
  • Location: Taunton, Somerset
  • Weather Preferences: Snow, thunder, strong winds
  • Location: Taunton, Somerset

Invest 92E has formed several hundred miles south-southwest of Manzanillo, Mexico. Convection is steadily increasing near a developing area of low pressure. Shear looks low and waters warm, so further development is possible. NHC say there is a 30% chance of 92E becoming the season's first tropical depression in the next 48hrs and a 50% chance in the next 5 days.

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Posted
  • Location: Taunton, Somerset
  • Weather Preferences: Snow, thunder, strong winds
  • Location: Taunton, Somerset

92E is becoming much better organised. Convection is blossoming over an increasingly well defined LLC. NHC are now assessing the chances of TC formation in the next 48hrs as 60%.

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Euro now indicating that the monsoonal gyre should produce another system in around a weeks time. Should be closer to the coast as well.

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Posted
  • Location: The Netherlands
  • Location: The Netherlands

Euro now indicating that the monsoonal gyre should produce another system in around a weeks time. Should be closer to the coast as well.

 

The NHC has also picked up the area you mentioned, giving it a 50% chance of developing into a tropical cyclone in the next 5 days:

 

 

 

1. An area of disturbed weather has formed several hundred miles south

of southeastern Mexico. This activity is currently poorly organized,

but environmental conditions should become conducive for gradual

development of this system during the next few days as it drifts

northward.

* Formation chance through 48 hours...low...near 10 percent

* Formation chance through 5 days...medium...50 percent

 

The GFS is also showing some development of the low pressure area, as it drifts northward toward the Mexican coast.

 

Posted Image

GFS MSLP T96 (06Z)

 

The low can be seen as the sub-1000 hPa low just to the south of eastern Mexico.

 

Sources:

http://www.nhc.noaa.gov/gtwo_epac.shtml

http://moe.met.fsu.edu/tcgengifs/

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Posted
  • Location: The Netherlands
  • Location: The Netherlands

The situation in the Eastern pacific is quickly becoming more interesting. The low pressure area mentioned above is taking shape to the south of the southeastern Mexican coast, and this AOI (area of interest) might also herald the beginning of the 2014 Atlantic hurricane season. How will this low evolve, and in which way might this low contribute to the formation of a tropical cyclone in the Atlantic? I'll try to find answers in the post given below.

 

Current situation

 

The area of interest (now been classified as 93E by NOAA) is currently not looking very well-organized (as of 22:00 UTC). Strong northerly shear is present over the system, as can be seen by the fact that any convective burst is sheared southward instantly. The shear has been preventing quick consolidation so far. This can be seen in the visible loop below:

 

Posted Image

Satellite image loop of 93E (Courtesy: NOAA)

 

Furthermore, the low level clouds do show some cyclonic curvature. This might be the beginning of a LLCC (low level circulation centre).

 

Another important factor is that vorticity analysis (a measure of the amount of curvature in a cyclone) shows that 93E is somewhat elongated in a WNW-ESE direction. This can be seen in CIMSS 850 hPa vorticity analysis below:

 

Posted Image

CIMSS 850 hPa vorticity analysis. 93E is located near 10N, 93W (as of 22:00 UTC)

 

Finally, an ASCAT-pass of 16:30 UTC, which captured the western part of 93E showed cyclonic winds near the centre of the cyclone, giving credence to the possibility that a LLCC may be forming. The ASCAT-analysis is given below:

 

Posted Image

KNMI ASCAT pass of 93E. The possible centre of 93E is located just to the east of the ASCAT pass.

 

The NHC currently has assessed development chances at 40% in the next 24 hours, and 70% within the next 5 days.

 

Forecasts of 93E

 

Most of the models forecast 93E to move north-northwestward toward the Mexican coast. However, spread between the models is still very high, and this might be the result of a forecasted slow motion of 93E. This spread is shown in the model analysis from UCAR:

 

Posted Image

Model forecasts of 93E (as of 18 UTC, 31-03-2014)

 

The ECMWF is showing 93E moving northward at a very gentle pace, and intensify into a moderate tropical storm in about 5 days:

 

Posted Image

ECMWF MSLP T120 (12 UTC run)

 

And now the interesting part comes. The ECMWF forecasts the system to make landfall in Mexico, and dissipate in that area. However, the remaining energy then reaches the Bay of Campeche. This would then result in the formation of an Atlantic tropical cyclone:

 

Posted Image

ECMWF MSLP T216 (12 UTC run)

 

The GFS, on the other hand, is much quicker with 93E, and brings it inland in about 84 hours. As a result, the remains of the cyclone reach the Bay of Campeche much more quickly, and this yields a much quicker Atlantic TC formation:

 

Posted Image

GFS MSLP T120 (12 UTC run)

 
In the extended period, the GFS intensifies the Atlantic low more than the ECMWF does/
 

Note that the formation of a possible Atlantic tropical cyclone is still way out, and it is therefore very likely that the model will flip-flow with this idea. Still, there is a general consensus that some kind of activity in the Atlantic will be possible (though with very large timing differences).

 

The situation does show some resemblance to the cyclones Arthur-Alma in 2008, in which the genesis of Atlantic tropical cyclone Arthur was aided by Eastern Pacific tropical cyclone Alma.

 

It is a very interesting situation, definitely worth watching during the next few days!

 

Sources:

http://www.ssd.noaa.gov/PS/TROP/floaters/93E/93E_floater.html

http://tropic.ssec.wisc.edu/real-time/windmain.php?&basin=atlantic&sat=wg8∏=vor&zoom=&time=

http://www.knmi.nl/scatterometer/ascat_osi_12_prod/ascat_app.cgi?cmd=showimageℑ=20140531_16_12.gif&clicklat=13&clicklon=-91&day=0&flag=yes&ascending=no

http://www.ral.ucar.edu/guidance/realtime/plots/northeastpacific/2014/ep932014/

http://moe.met.fsu.edu/tcgengifs/

http://en.wikipedia.org/wiki/2008_Atlantic_hurricane_season

Edited by Vorticity0123
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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Cherry, 90%. Looks like a clear cyclonic turn to me, probably already a TD.

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Posted
  • Location: falkirk, scotland, 16.505m, 54.151ft above sea level
  • Weather Preferences: dry sunny average summers and really cold snowy winters
  • Location: falkirk, scotland, 16.505m, 54.151ft above sea level

tropical depression 2E has formed in the eastern pacific just off the coast of Mexico moving slowly north with high potential for flooding in parts of Mexico and Gautamala

 

http://www.weather.com/news/weather-hurricanes/tropical-depression-two-e-mexico-20140530

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Posted
  • Location: Tiree
  • Location: Tiree

94E

 

A broad low pressure area located a couple hundred miles southwest
of Acapulco, Mexico, continues to produce a large area of
disorganized showers and thunderstorms. Environmental conditions
appear conducive for gradual development, and a tropical depression
will likely form during the next few days while the low moves
generally northwestward at 5 to 10 mph.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...high...80 percent.

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