Somerset Squall

Haiyan has continued to weaken as it crosses the South China Sea (SCS). Winds are down to 100kts, cat 3 on the SS scale. The cause of the weakening is primarily down to cooler sea temps in the central and western parts of the SCS. Despite the weakening, Haiyan is still a major threat to Vietnam. Haiyan should make landfall as a cat 2 on the SS scale, but the angle of approach is the greatest concern. Haiyan is moving west-northwestwards but it forecast to turn northwest onto the coast of Vietnam. This motion brings the front right quadrant (northeast) onshore first, where the strongest winds and highest surge are. The shape of the coastline and the small area of the Gulf Of Tonkin is likely to worsen the storm surge as the storm approaches from the southeast. Despite Haiyan being weaker, it is still carrying the surge from when it was much stronger. This surge will likely bring dangerous flooding, especially when combined with the torrential rainfall.

I am unsure of the link really Styx, but the West Pacific tends to have above average seasons during El Nino whereas the Australian season tends to be below average as a whole during El Nino and conversely during La Nina the West Pacific tends to be below average and Australia above average, but as far as I am aware we are in Neutral at the moment? Neutral suggests an average Australian season, but anything could happen as we all know (Atlantic season 2013 being a prime example).

The third tropical cyclone of the 2013 season has formed, the first to form in the Arabian Sea (the other two, Mahasen and Phailin, formed in the Bay Of Bengal) this year. 03A is located a few hundred miles off the east coast of Somalia. Winds are currently at 35kts. The storm has some fairly deep convection over the LLCC, but with little or no banding. Shear is fairly low and waters are warm, so 03A could strengthen a little on the westward track over the next day or so prior to landfall. Dry air off Somalia could hinder development though, so 03A may not get a lot stronger than it is now.

Haiyan has continued to weaken and is now been downgraded from a super typhoon to a typhoon, with winds of 125kts (still cat 4). The typhoon is still pretty symmetrical, but the eye is rather ragged. Haiyan is moving into the South China Sea now. With warm waters and low shear expected over the next 12 hours, JTWC forecast Haiyan to briefly become a super typhoon again before shear increases and sea temps cool along the track towards Vietnam. Haiyan is still expected to be a fairly intense system as it landfalls Vietnam, despite it being a lot weaker than it's former self.

Haiyan has finally lost cat 5 status, but was a cat 5 for 48 hours, which is impressive. Winds are still not to be sniffed at however, at 135kts, high end cat 4.

It seems like they are actually quoting PAGASA's wind estimates, which, as per usual, are far too low.

Jeff Masters latest thoughts http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2573

Indeed, if the JTWC's gust estimate is correct, the wind gusts could be reaching 235mph now.

The remnant low of TD 30W has moved into the Gulf Of Thailand and appears to be reorganising. Convection is increasing near the currently ill defined LLCC. JTWC assess development chances as MEDIUM, due to the low shear and warm sea temps, but proximity to the Malay Peninsula, which could, at least temporarily, disrupt further development as the remnants cross it.

Landfall has occured on Eastern Samar according to PAGASA just now. Haiyan looks to remain a cat 5 well into the island group of the Philippines, as it is going to take a lot of land interaction to cause Haiyan to significantly decay.

Me neither. It's foolhardy it really is!

A beautiful but scary image: And I can't believe this thing has sustained winds of 170kts!! It's almost like Haiyan needs another category! And I strongly suspect the pressure is lower than 895mb!

Officially maybe, but I suspect unoffically many have in the West Pacific and most likely Cyclone Monica in 2006 in the Australian region. Do you mean worldwide or just this basin? Megi 2010 is another one, down to 885mb officially. But not 190mph surprisingly.This is why there should be recon in all basins IMO. For the sake of records if not anything else.

What are the others Sainsbo? I know of Camille, Allen, Gilbert I think?

WOW. JUST WOW. JTWC have upped the winds to 165kts this afternoon, which is the highest for any storm I've personally tracked. I never expected Haiyan to get quite this strong!

Still a 150kt cat 5 Super Typhoon this morning:

JTWC have upped the winds to 150kts in their latest advisory, which makes Haiyan the strongest tropical cyclone of the year worldwide by their estimates. JMA expect a peak of 895mb, which is the strongest since Super Typhoon Megi in 2010. How I wish recon operated in this basin! It's a damn shame that it doesn't, especially when the West Pacific basin is home to the most frequent and intense cyclones in the world.

Haiyan is now a category 5 Super Typhoon with winds of 140kts according to the last JTWC update. However, I think Haiyan could be stronger than this or getting stornger than this. I feel so sorry for those in the path of this fierce beast! Palau, the island south of Haiyan in the image, may be spared the strongest winds as the eye passes to the north, a very close shave indeed. The rains here are obviously of great concern at the current time. The Philippines look to be in the firing line from the most dangerous winds and rain however.

Haiyan has further intensified and is now a 130kt super typhoon (high end cat 4 on the SS scale). The eye has become even smaller and is only 6 nautical miles wide according to JTWC. Haiyan is expected to become the season's 4th cat 5 later today (and the world's 5th).

Shear has been higher than expected in the region of 30W today. The depression briefly became a tropical storm this afternoon according to JTWC, though JMA did not make the upgrade. JTWC have now downgraded 30W back to a tropical depression. Shear has left the rather ill defined LLC almost entirely exposed this evening, and winds have fallen to 25kts. Significant recovery looks unlikely before 30W moves inland tomorrow. Because the depression is not expected to strengthen much, it is unlikely to survive the trip over land into the North Indian Ocean as a tropical cyclone, but it could still regnerate in this basin later.

Haiyan is rapidly intensifying. An well defined eye has cleared out within the solid central dense overcast. Winds are now at 105kts (cat 3 SS scale) according to JTWC. The rapid strengthening is expected to continue, with Haiyan expected to become a 130kt super typhoon in the next 12 hours then cat 5 intensity prior to slamming into the Philippines. A serious scenario for sure.

Indeed Coast, winds are now up to 65kts, making Haiyan a cat 1 typhoon on the SS scale. The solid central dense overcast perisists, flanked by strong banding, and an eye feature is beginning to emerge. I expect some rapid strengthening this afternoon, as shear remains low and waters warm. Outflow is near radial and remains impressive, further supporting the idea of rapid intensification.

Convection has increased and become better organised in association with 30W this evening. Winds have increased to 30kts. 30W is emerging into the southern half of the South China Sea currently, where shear looks to be quite low, and waters warm. Therefore, 30W should soon become a tropical storm. JTWC expect 30W to peak just below typhoon strength before making landfall in southern Vietnam. 30W is expected to weaken to a tropical depression before emerging briefly into the Gulf Of Thailand, then cross the Malay Peninsula into the North Indian Ocean. 30W may not make it this far, but it'll be interesting to see if it does!

Haiyan has continued to strengthen, and winds are now at 55kts. Haiyan has developed a solid central dense overcast flanked by strong banding features. Shear remains low, waters warm and outflow excellent. Based on the structure of Haiyan, and the very favourable environment ahead, Haiyan is likely to enter a rapid intensification phase over the next day or so. JTWC expect a peak of 130kts, which looks likely. In fact, it wouldn't be surprising to see another cat 5 IMO. This looks like it is going to be devestating for the Philippines.

Interesting blog from Jeff Masters. Apparently this October was the most active on record for the number of typhoons in the West Pacific. And despite us now being in November, it shows no signs of slowing down.