eastern pacific Major Hurricane Simon

[Somerset Squall]

Yet another tropical depression has formed in the Eastern Pacific, south of Manzanillo, Mexico. 19E has winds of 25kts. The depression consists of a partially exposed LLC, with some deep convection to the west of the centre. Moderate shear is affecting 19E, but is expected to ease in about 24hrs time, which should allow some strengthening. Just how much is uncertain as always; NHC are forecasting a peak of 55kts. If 19E stays away from the coast, I think it could become stronger. Rachel did the same and became the 10th consecutive named storm to become a hurricane. Will 19E become the 11th?

Track wise, a generally west to west-northwest track away from Mexico is predicted for the next few days. There is considerably more uncertainty after that due to model disagreement. 19E should reach it's peak in a few days then start to weaken as it encounters cooler waters west of Baja California.

I'm hoping this one defies forecasts and becomes a decent hurricane. The next name on the list is Simon, which is my name! The previous two incarnations of Simon in 1984 and 1990 peaked at strong tropical storm intensity, failing to make hurricane status.

Edited October 1, 2014 by Somerset Squall

[Somerset Squall]

19E has been upgraded to Tropical Storm Simon, with winds of 45kts. Simon appears to be developing a small inner core, with an area of persistant convection over it. Banding features flank the storm also. Simon has moved south of the initial track forecast. Aside from that, the track forecast is unchanged; a west-northwestward track followed by a turn to the north is still expected. Simon has another couple of days to strengthen over warm waters and low shear, and it is forecast to become a hurricane in this time. Based on the

apparent formation of a small inner core, rapid strengthening is a possibility.

[Somerset Squall]

Simon has strengthened steadily to 55kts. The storm has a central dense overcast, from which there have been hints of an eye. Strong banding features are wrapping into the western quadrant. Simon seems close to becoming a hurricane. Due to the small size of the inner core, there is still a chance of rapid intensification over the next day or so. Simon should continue to head just north of due west for the next day or so followed by a turn to the north. Thereafter, there is strong model disagreement, with some models turning Simon northeast into Baja California, and others dissipating Simon further west over water in several days time.

This image shows Simon moving very near Socorro Island:

[Somerset Squall]

Simon has strengthened overnight, and is now a 75kt category 1 hurricane. This is the 11th consecutive named storm to become a hurricane in the East Pacific this year, which shatters the previous record of 8 in 1992.

Simon isn't done with it's intensification it seems. The system has a very small eye emerging from the solid central dense overcast. Shear is virtually non-existant, outflow is excellent and waters are warm with high oceanic heat content. Therefore, NHC forecast a peak of 95kts, though there is a chance that Simon could become a major hurricane (100kt+ winds). Simon has about another 24hrs if it's going to do this.

[Vorticity0123]

Simon has strengthened overnight, and is now a 75kt category 1 hurricane. This is the 11th consecutive named storm to become a hurricane in the East Pacific this year, which shatters the previous record of 8 in 1992.

It is a very remarkable streak, impressive to say the least. Simon has also become the 14th hurricane in total (or 13 if one excludes Genevieve, which became a hurricane in the central Pacific). If Simon would end up to become a major hurricane (and yes, if it does so it has definitely been an overachiever   ), it would become the 9th major hurricane in this season (including Genevieve). This would mean this hurricane season is one major hurricane shy of equalizing the record of the most amount of major hurricanes to have ever formed in any Eastern Pacific hurricane season since 1949. It has to be noted that this is still speculation, though.

 

Meanwhile, Simon continues to steadily intensify, with conditions being extremely favorable for development, as noted by Somerset Squall. However,  in the latest discussion (as of 09:00 UTC) the NHC noted that: "the eye of Simon was open in the northwest quadrant", meaning that the inner core of the storm is not yet very well organized, decreasing the likehood of rapid intensification. This can also be seen in MIMIC TC imagery from CIMSS:

 

CIMSS MIMIC imagery of Simon in the last 24 hours. Note that the image auto-updates itself.

 

What can be seen is, as of 11:00 UTC, the inner core of Simon has become much better organized during the past few hours, with the eyewall (indicated by the red colours) attaining a more circular pattern. However, on the last few frames, it also becomes evident that the eyewall is weakly defined or nonexistent in the eastern and northeastern quadrants (shown by the absence of red colours in that area). As a result, rapid intensification might be delayed some or not occur at all, if this gap remains in place. Still, if the eyewall would be able to close off anytime in the next 24-36 hr, rapid intensification is a distinct possibility.

 

Sources:

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

http://tropic.ssec.wisc.edu/real-time/mimic-tc/2014_19E/webManager/mainpage.html

http://www.nhc.noaa.gov/text/refresh/MIATCDEP4+shtml/040856.shtml

Edited October 4, 2014 by Vorticity0123

[Vorticity0123]

So much of the slow intensification that was anticipated. An eye has become very well defined and a circular, albeit slightly ragged, eyewall has developed. This is illustrated in the Dvorak satellite loop below:

 

Dvorak satellite loop of Simon.

 

Also note the vigorous outflow to the north of the system, while some outflow is also evident on the western and southern portion of the system. 

 

Given the current satellite presentation, as well as the intensity estimate from the NHC, it seems imminent that Simon becomes the ninth major hurricane of the season. 

 

Source:

http://earth.nullschool.net/#current/wind/isobaric/700hPa/orthographic=-112.45,26.47,1024

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

[Somerset Squall]

Simon has continued to rapidly intensify, and is now a 95kt, cat 2 hurricane. The eye has become more distinct, and is surrounded by very cold cloud tops. Simon is expected to become a major hurricane later today then start weakening tomorrow.

[Somerset Squall]

Simon became a major hurricane last night. It peaked at 115kts, making it a category 4 on the SS scale. Simon is the eighth major hurricane of the season, and this ties the record for major hurricanes with 1983, 1992 and 1993.

Simon is now weakening, though it's still a major hurricane with winds of 100kts. A combination of an eyewall replacement cycle, increasing shear and passage over cooler waters have caused this weakening. Simon should continue weakening as it turns northeast towards Baja California. If Simon reaches Baja California intact, it should only be a weak tropical storm or a tropical depression. Nevertheless, a heavy rainfall event is expected for northwest Mexico and the southwest US through the week.

[Somerset Squall]

Simon has turned northeast towards Baja California. The storm has continued to weaken under strong shear, with winds currently at 45kts. A tropical storm watch has been issued for Baja, although Simon will be very weak as it reaches the coast.