eastern pacific Major Hurricane Amanda

[Somerset Squall]

The first tropical depression of the 2014 Eastern Pacific season has formed several hundred miles south-southwest of Manzanillo, Mexico, from invest 92E. 01E has a well defined LLCC, and convection has become persistant over this centre. 01E is being steered slowly west by a ridge over Mexico, but the influence is weak, therefore, motion is expected to be slow. Shear is low, and waters warm, so strengthening seems likely. Just how much strengthening is uncertain, but given the increasingly impressive structure of the depression and favourable environment, rapid strengthening is a possibility in the near term, as evidenced by the ships rapid intensification index indicating a 42% chance of a 25kt increase in intensity in the next 24hrs. 01E looks to have about 4 days in this favourable envrionment, so I think 01E does have a shot at becoming a hurricane unless shear increases prematurely.

Edited May 25, 2014 by Somerset Squall

[summer blizzard]

Finally, we're back.

[Somerset Squall]

01E continues to organise and has become Tropical Storm Amanda, with winds of 35kts. Convection continues to build over the LLCC, with banding features wrapping into the storm. Amanda is expected to become a hurricane in a few days time, but it could occur sooner as there is a chance of rapid intensification.

[Vorticity0123]

01E continues to organise and has become Tropical Storm Amanda, with winds of 35kts. Convection continues to build over the LLCC, with banding features wrapping into the storm. Amanda is expected to become a hurricane in a few days time, but it could occur sooner as there is a chance of rapid intensification.

 

Indeed, the first named storm of the 2014 Eastern Pacific Hurricane Season has taken shape. This is about 18 days before the average occurrence of the first tropical storm (10 June)¹.

 

When looking at visible satellite imagery (as of 21:00 UTC), it looks as if Amanda is steadily becoming better organized. In fact, a comma-shaped cloud system appears to have developed, with a well-defined band wrapping almost completely around the centre of the cyclone. This can be seen in the satellite loop below:

 

Visible satellite imagery loop of Amanda (Courtesy: NOAA)

 

Also of note is that the circulation of Amanda is very well-defined. However, despite the well-organized visible satellite appearance, DVORAK satellite imagery shows that the bands of Amanda are still fragmented, and deep convection is sparse. (as of 21:00 UTC).

 

DVORAK satellite image of Amanda (Courtesy: NOAA)

 

In addition to the fragmented banding, the NHC noted in their discussion (in the fifth advisory) that there might be some displacement of the low level centre compared to the mid-level centre (i.e. the centres are not perfectly stacked above each other). This could prevent Amanda from intensifying rapidly in the short term.

 

It will be interesting to see how Amanda will evolve over the next few days.

 

 

Sources:

¹:http://www.nhc.noaa.gov/climo/#bac

http://www.ssd.noaa.gov/PS/TROP/floaters/01E/imagery/bd0-lalo.gif

http://www.nhc.noaa.gov/text/refresh/MIATCDEP1+shtml/232032.shtml

http://tropic.ssec.wisc.edu/real-time/windmain.php?&basin=eastpac&sat=wg9∏=vor&zoom=&time=

Edited May 23, 2014 by Vorticity0123

[Somerset Squall]

Looking more and more impressive:

 

[summer blizzard]

Very good. Probably a hurricane now or near enough.

[Somerset Squall]

Amanda has rapidly strengthened overnight, with winds now at 55kts according to NHC. Amanda has developed a circular central dense overcast feature and is developing an eye. Amanda should become a hurricane later today, and then should continue to rapidly strengthen as shear remains very low and waters warm. NHC forecast a peak of 90kts, but Amanda could easily become stronger than this due to the tight inner core and the very favourable envrionment. Don't be surprised to see Amanda attain major hurricane status over the next day or so (100kt+ winds, cat 3 or above on SS scale).

 

Amanda is currently pushing slowly west-northwestwards, and this motion will continue for about another 24 hours. After this time, ridging is expected to strengthen east of Amanda, and a trough is expected to approach from the west. This should accelerate Amanda to the north, sending the cyclone over cooler waters and increasing shear, which should cause weakening beyond 48 hours.

 

The Eastern Pacific season is certainly in business

[Somerset Squall]

Amanda has become the season's first hurricane, with winds of 65kts. SHIPS rapid intensification index shows a 60% chance of a 40kt intensity gain in the next 24hrs. So it is clear that the current rapid intensification is probably not over.

[Sainsbo]

Amanda has finally been upgraded to a hurricane, with sustained winds of 75mph.

 

For a weak category one, she looks very impressive on satellite. CDO starting to build and good outflow, definitely agree with SS about rapid intensification likely.

 

Starting to look annular to me aswell? Could be the first of many to come.

 

Looks like I got beaten to it, ahha.

Edited May 24, 2014 by Sainsbo

[Vorticity0123]

Amanda seems to be increasing in organization after a brief lull during the past 12 hours or so. In fact, an eye has become visible within the cyclone. Even though it is still poorly defined (as of 21:50 UTC), this could be the start of another period of rapid intensification. This is also in line with RI (rapid intensification) index from SHIPS, as Somerset Squall noted.

 

Visible satellite image of Amanda (Courtesy: Naval Research Laboratry US)

 

Of note is that the NOAA is forecasting Amanda to become a major hurricane in about 36 hours. This would be a very early appearance of the first major hurricane in the Eastern Pacific. Climatologically, the first major hurricane in the Eastern Pacific forms at July 19¹. Therefore, if Amanda would become a major hurricane, it would be a very unusual occurrence.

 

 

Starting to look annular to me aswell? Could be the first of many to come.

 

It seems to me that Amanda is not (yet) an Annular cyclone, as banding features are still present around the storm. Still, it remains an impressive start of the 2014 EPAC hurricane season! 

 

Sources:

http://www.nrlmry.navy.mil/TC.html

http://en.wikipedia.org/wiki/Annular_tropical_cyclone

http://www.nhc.noaa.gov/text/refresh/MIATCDEP1+shtml/242033.shtml

¹http://www.nhc.noaa.gov/climo/

Edited May 24, 2014 by Vorticity0123

[Sainsbo]

 

It seems to me that Amanda is not (yet) an Annular cyclone, as banding features are still present around the storm. Still, it remains an impressive start of the 2014 EPAC hurricane season! 

 

Ahh, my mistake. Thanks for clearing that up.

[Somerset Squall]

Sporting a pinhole eye now, Amanda should be a major hurricane very soon:

 

 

 

[knocker]

Intense Hurricane Amanda has continued to rapidly intensify. T>7.0 Intensity 125 knots+ Still 12-24 hours to peak

 

pic.twitter.com/U0NaXL1LZz

[Somerset Squall]

Amanda has bombed overnight. Winds are now at 120kts, cat 4 on the SS scale, making Amanda the season's first major hurricane. Amanda is the second earliest major hurricane on record, only behind Major Hurricane Bud of 2012. However, Amanda is stronger than Bud (Bud's peak was 100kts), so Amanda is the strongest storm for so early in the season on record. It is not yet the strongest May hurricane; that title is still held by Major Hurricane Adolph in 2001 (125kts), but Amanda does have a real shot at beating this as Amanda could strengthen further through the rest of today. Amanda has a ring of very deep convection surrounding a small, clear, well defined eye presently, and is not showing any sings of weakening yet.

 

Edited May 25, 2014 by Somerset Squall

[Somerset Squall]

Satellite loop of Amanda:

 

Edited May 25, 2014 by Somerset Squall

[Vorticity0123]

What an impressive start of the 2014 EPAC hurricane season this is! The cyclone is already stronger than the strongest Eastern Pacific hurricane in 2013 (which was Raymond, which peaked at 105 kt).

 

Amanda currently looks very well organized, though the convection is somewhat thin on the southwestern quadrant of the system (See the satellite image from Somerset Squall above). Furthermore, the eyewall seems to be somewhat elongated north-south, as can be seen in the MIMIC imagery below:

 

MIMIC-TC satellite imagery loop of Amanda (Courtesy: CIMSS)

 

However, what can also be deduced from the MIMIC loop is that very low brightness temperatures (the dark red colours on the image; indicative of a strong eyewall) now completely encompass Amanda (as of 10:23 UTC). This is indicative of a well-organized major hurricane, and shows that the cyclone is possibly still in the process of intensifying.

 

The continued intensification is also reflected in CIMSS satellite trends:

 

CIMSS ADT satellite intensity estimates trend (Courtesy: CIMSS).

 

Also note the very rapid intensification period between 00 and 06 UTC, May 24 2014 (an increase of about 30 kt in 6 hours). 

 

Finally, to show this quick deepening period mentioned above, a beautiful satellite loop of Amanda showing the rapid development of the eye:

 

IR satellite loop of Amanda (Courtesy: Wunderground)

 

Sources:

http://en.wikipedia.org/wiki/2013_Pacific_hurricane_season

http://tropic.ssec.wisc.edu/real-time/mimic-tc/2014_01E/

http://tropic.ssec.wisc.edu/

http://icons.wunderground.com/data/wximagenew/k/KEEPEROFTHEGATE/3904.gif

Edited May 25, 2014 by Vorticity0123

[knocker]

TCHP

[Cookie]

Stunning hurricane she's a beauty

[Sainsbo]

Max sustained winds of 155mph (135kts) now, just shy of a Category 5, which makes it the strongest May hurricane on record.

 

Pressure at 932mb.

 

Beautiful to look at.

 

[Somerset Squall]

Wow, what a debut the first usage of the name Amanda is turning out to be. Amanda has taken Adolph's place as the strongest May hurricane on record as Sainsbo has stated. I'd love Amanda just to make that 5kt jump and become a cat 5, if she is to do it, it will need to be in the next 6 hrs really.

Amanda has slowed even further and is crawling northwards at 2kts. This is already causing upwelling of colder water to the ocean surface according to NHC, which will serve to weaken Amanda soon. Shear rises further north, which will eventually bring about this amazing hurricane's demise.

[knocker]

Hurricane Amanda has triangular shaped eye as dry air entrains from west ... eyewall replacement cycle signal

 

pic.twitter.com/d696iyHUh0

 

Sea Surface Temps of 28.5°C + clearly sufficient for near Category 5 strength of Hurricane Amanda

 

pic.twitter.com/woLvWXI0nz

[Somerset Squall]

Amanda has weakened slightly, to 130kts, still a strong cat 4. The eye has become a little cloud filled, and cloud tops have warmed in the central dense overcast. An eyewall replacement cycle looks like it could begin soon. If this does occur, Amanda could weaken fairly briskly as dry air manages to intrude further into the core of Amanda.

[summer blizzard]

Beauty.

[Somerset Squall]

Shear has continued to affect Amanda today. The hurricane is still a cat 4 on the SS scale, but winds have reduced to 115kts. The eye is intermittently visible on satellite imagery. Amanda will continue to weaken over the next few days as shear continues to rise and waters cool along track.

[Somerset Squall]

After looking rather lopsided the afternoon and the eye disappearing from view, Amanda has made a comeback this evening, with a more symmetrical central dense overcast and a visible eye once more. However, winds continue to fall, and Amanda is now a 105kt cat 3. Weakening will continue as Amanda moves slowly northwards.