2015 WPAC Season

[euro6208]

http://www.storm2k.org/phpbb2/viewtopic.php?f=76&t=117168

99W Thread for system in Eastern Micronesia.

[CrazyC83]

I think 40 tropical storms is not out of reach this year in the WPAC, and super typhoons in double digits as well. I see 1991, 1992 and 1997 as the main analog years.

[xtyphooncyclonex]

I see 2004, 1997 and 1965 as our analog years.

[euro6208]

http://www.storm2k.org/phpbb2/viewtopic.php?f=76&t=117156

Maysak...

2015 is now the only season since records began in 1945 to feature three typhoons during the first three months of the year (January, February, and March), and also the first season to have two major typhoons (Category 3 or stronger) during the first three months of the year. The other major typhoon of 2015 was Typhoon Higos, which topped out as a Category 3 storm with 120 mph winds in February. Maysak is the fourth named storm so far in 2015 in the Western Pacific, and only one other year since 1945 had more named storms by this point--1965, when there were five named storms by the end of March. The previous record for early season typhoons (during January, February, and March) was two, set in 2005, 1979, and 1955. Major typhoons of Category 3 or stronger intensity are rare before April, and only fifteen such storms have been observed between 1945 - 2014.

*Higos peaked as a category 4!

Storms and seasons going record after record this year!

[euro6208]

I think 40 tropical storms is not out of reach this year in the WPAC, and super typhoons in double digits as well. I see 1991, 1992 and 1997 as the main analog years.

I see 2004, 1997 and 1965 as our analog years.

At the rate we are going, 2015 is ahead of those years by a mile...

Going to be a long brutal year...

[cycloneye]

Dr Jeff Masters made a good discussion about how 2015 compares with past seasons in the first three months of the year.

A record early start to typhoon season
According to the Joint Typhoon Warning Center (JTWC) database, 2015 is now the only season since records began in 1945 to feature three typhoons during the first three months of the year (January, February, and March), and also the first season to have two major typhoons (Category 3 or stronger) during the first three months of the year. The other major typhoon of 2015 was Typhoon Higos, which topped out as a Category 3 storm with 120 mph winds in February. Maysak is the fourth named storm so far in 2015 in the Western Pacific, and only one other year since 1945 had more named storms by this point--1965, when there were five named storms by the end of March. The previous record for early season typhoons (during January, February, and March) was two, set in 2005, 1979, and 1955. Major typhoons of Category 3 or stronger intensity are rare before April, and only fifteen such storms have been observed between 1945 - 2014. Two of these were Category 5 super typhoons: Super Typhoon Ophelia of January 1958 with 160 mph winds, and Super Typhoon Mitag of March 2002, also with 160 mph winds.

The unusually early start to typhoon season is due, in part, to exceptionally warm waters in the typhoon breeding grounds just west of the International Date Line between 5 - 10° latitude, due to the weak El Niño event that is occurring. Water temperatures there are about 1 - 2°C (1.8 - 3.6°F) warmer than average. Also aiding typhoon formation this month was the strongest MJO event since record keeping began in 1974, which moved through the Western Pacific in mid-March. This MJO event generated an unusually strong band of west-to-east blowing surface winds near the Equator (a "westerly wind burst") that helped spin up Maysak and the storm that preceded it, Tropical Storm Bavi. This "westerly wind burst" will be strengthened by the counter-clockwise flow of air around Maysak, increasing the chances of El Niño lasting into the summer and potentially strengthening this fall. This process could potentially be aided by another tropical storm that the GFS models predicts will develop late this week from Invest 99W, in a location similar to where Maysak developed.

[cycloneye]

Philip Klotzbach @philklotzbach · 57m 57 minutes ago
The NW Pacific has already accumulated as much ACE in 2015 (36 units) as did the North Atlantic in all of 2013.

[euro6208]

Very interesting statistic on this season from NWS. These early season Majors like to visit Micronesia...

Here is a study of the frequency of Major Typhoons (115 mph/100kt) that have occurred in the WPAC since 1945 during the first 3 months of the year. In 70 years we have had 15, so we can expect 1 in every 4 to 5 years (statistically speaking). Of course, this year we already have had two...Higos and Maysak.

[euro6208]

Wow! Record season even more?

CMC and EURO developing Noul later this month...Really? We'll see...

[cycloneye]

WPAC is way ahead of average for April 5 as ACE units jumped after Maysak to 48.58.

[xtyphooncyclonex]

After STY Isa, what were the ACE values for WPAC? Are we ahead now in 2015?

[xtyphooncyclonex]

Answered my own question.

El Niño years YTD ACE thru April

(1980 onwards)

1982 32.2725
1983 0
1986 12.7575
1987 8.6725
1991 11.675
1994 8.69
1997 46.5625
2002 32.74
2004 44.735
2006 0
2009 0
2015 48.58

[euro6208]

Update on April 6th...

5 Tropical Storms / 3 Typhoons / 2 Major Typhoons in this record season.

*Ignore TS 5 as it is Haishen...


1 Typhoon-1 MEKKHALA 13-18 JAN 70 1
2 Typhoon-3 HIGOS 07-11 FEB 105 3
3 Tropical Storm BAVI 11-18 MAR 50 -
4 Super Typhoon-5 MAYSAK 27 MAR-05 APR 140 5
5 Tropical Storm HAISHEN 03-06 APR 45 - Active
6 Tropical Storm FIVE 03-04 APR 45 -

[euro6208]

GFS is joining in now developing possible Noul and Dolphin...

[xtyphooncyclonex]

I'm gonna issue another forecast.

April 2015 Unofficial Typhoon Season Forecast*

EXPLANATION
The 2015 WPAC typhoon season is extremely likely to be above-average in activity. As of now, there have been 3 typhoons, together with 2 more weak TS which contributed to an unusual amount of ACE, which is the highest to-date (before May) since records began in 1970. However, activity is expected to be less over the far western part of the basin, and is to be concentrated on the eastern parts east of 130ºE. Storm formation is expected to be closer to the equator, and farther East than normal. This is due to the different placement of the West Pac High and increased cloudiness near the IDL. Conditions over the East parts will be more favorable, having lower wind shear and warmer SSTs as a result of a recurring El Niño, which is expected to intensify later in the season.

ACTIVITY NUMBERS
31 tropical storms
21 STRONG typhoons
13 VERY STRONG or higher

465 ACE (hyperactive)

Official Classification of Typhoon Intensity
In Knots
<33 kts : TD
34-47 : Tropical storm
48-63 : Severe tropical storm
64-84 : Strong typhoon
85-104 : Very strong typhoon
105> : Violent typhoon

Unofficial Classification of ACE
In Units
<200 : Inactive
200-230 : Very Weak
230-265 : Weak
265-280 : Below average
280-320 : Average
320-335 : Above average
335-370 : Active
370-400 : Very Active
400 > : Hyperactive

*The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the JMA products.

[euro6208]

I can't even begin to describe how favorable this season looks...

Definitely active but hoping everyone is prepared...The islands in Micronesia as always should bear the brunt of this season enhanced nino...

[xtyphooncyclonex]

Comparing this season to the seasons since 2002... first category 5

Off: Record was in 1958, the season had it with Typhoon Ophelia during the latter half of January

Month is the whole number

Decimal is
First week - 0
First week (out of 5) - 0.2
Second week - .25
Second week (out of 5) - 0.4
Third week or half - .5
Third week (out of 5) - 0.6
Fourth week or latter half - .75
Fourth week (out of 5) - 0.8
(extra fifth week - .9)
Last day - .99

2015 had it with Typhoon Maysak during the last day of March (3.99)
2014 had it with Typhoon Halong during the first week of August (8.2)
2013 had it with Typhoon Francisco during the latter half of October (10.8)
(or if JT did not downgrade, Typhoon Usagi during the latter half of September.. still )
2012 had it with Typhoon Sanba during the middle of September (9.5)
2011 had it with Typhoon Songda during the latter half of May (5.8)
2010 had it with Typhoon Megi during the middle of October, and was the only cat 5 of the season (10.5)
2009 had it with Typhoon Choi-wan during the middle of September (9.5)
2008 had it with Typhoon Jangmi during the last week of September (9.9)
2007 had it with Typhoon Sepat during the middle of August (8.5)
2006 had it with Typhoon Saomai during the second week of August (8.4)
2005 had it with Typhoon Haitang during the middle of July (7.5)
2004 had it with Typhoon Nida during the middle of May (5.5)
2003 had it with Typhoon Maemi during the second week of September (9.4)
2002 had it with Typhoon Mitag during the first day of March (3)

On average, it would be during the middle of July

[xtyphooncyclonex]

El Niño Years ACE Comparison

(1970 onwards)

[euro6208]

El Niño Years ACE Comparison

(1970 onwards)

So 2015 is ahead of every el nino years

On Maue's site, it's listed as 48.58 for this year now...

[euro6208]

Models have backed off in developing Noul...

The calm before the storms?