western pacific Super Typhoon Halong

[Somerset Squall]

Tropical Depression 11W formed yesterday to the southeast of Guam, and has since strengthened into a 50kt tropical storm named Halong. Halong has deep convection over the LLCC, with banding features taking shape nicely in the southern quadrant. Halong is in an area of low shear and has well developed equatorward outflow, but poleward outflow is being surpressed by troughing to the north. This troughing is expected to lift out over the coming days, allowing Halong to further intensify, into a typhoon. Halong is expected to pass north of Guam in a northwesterly direction, before veering north as the storm reaches the western extent of the steering ridge to the north.

 

[Somerset Squall]

Halong has struggled over the last 24hrs with stunted poleward outflow and now moderate shear. Winds reached 55kts yesterday, but have now fallen back to 50kts. The LLCC has been exposed on occasion to the north of the deep convection. The environment is still expected to improve a little over the coming days, allowing some intensification. Halong is most definitely hampered by the extremely large TS Nakri to it's northwest however. Halong is a midget in comparison!

[Somerset Squall]

Halong looked a mess this morning as it got heavily sheared, but the storm has made a bit of a comeback this evening. Winds fell to 45kts, but are now back up to 50kts. Shear is still moderate to high, but the equatorward outflow is robust, which is allowing Halong to hold it's own. The shear is expected to ease a little but remain at moderate levels over the coming days as Halong swings to the north in TS Nakri's wake. With the strong equatorwrd outflow expected to persist, Halong should strengthen if shear reduces at all. This is forecast by JTWC, which expect Halong to eventually become a fairly robust typhoon.

 

[Somerset Squall]

Halong has overcome the shear and is intensifiying rapidly. Winds are up to 75kts according to the 9pm JTWC update, but satellite imagery indictes that Halong has continued to rapidly intensify since that time and is clearly now a lot stronger. An eye developed this afternoon, which has now cleared out. Sher has eased significantly over Halong as TS Nakri moves away, and the way things are going, we could see a very intense typhoon here once Halong has completed this round of rapid intensification.

 

Edited August 1, 2014 by Somerset Squall

[Somerset Squall]

Halong continues to rapidly intensify. Winds are up to 100kts in the latest JTWC advisory, though I expect them to be somewhat higher next advisory (around 9-10am).

[Sainsbo]

Winds of 115kts (~130mph) now, cat 4 on the SS Scale. Halong is expected to peak with sustained windspeeds of 130kts (~150mph), on the verge of Super Typhoon Status. Quite a difference to the predicted peak of a weak to moderate category 2 the JTWC were forecasting last night.

 

[Sainsbo]

And finally we have Super Typhoon Halong. Sustained windspeeds of 135kts (155mph), expected to peak at 140kts (160mph), making it Cat 5 on the SS scale. Convection is still increasing, and conditions are favourable for further intensification for another 24 hours or so.

Edited August 2, 2014 by Sainsbo

[Somerset Squall]

Wow that is some serious rapid intensification, and that also under moderate northerly shear! The outflow in an equatorward direction has really cancelled out the affects of the northerly shear. Now just 5kts away from becoming the season's first cat 5!

[Somerset Squall]

Halong has become the world's second cat 5 of 2014 (the other was Gillian in the South Indian Ocean in March), and the first cat 5 of the Western Pacific season. Winds are now at 140kts. Halong will continue west-northwestwards for about another 24hrs, and then is expected to push north-northwestwards as an approching trough breaks down the ridge to the north. Halong will be approaching Okinawa in about 4 days time. The super typhoon is expected to maintain cat 5 intensity for about 24hrs, with a slow weakening expected thereafter.

 

 

 

[knocker]

Neat

 

Just look at the eye of the monster. #Halong pic.twitter.com/rAjV9IN3Zt

[Somerset Squall]

Strong northerly shear has impinged once more on Halong as it moves northwards towards southwest Japan. The eye is cloud filled, and the convection is thinning to the north of the eye. Winds are down to 115kts, cat 4 on the SS scale. Further weakening is expected on approach to Japan, but the system could still be a typhoon at landfall.

[Somerset Squall]

Halong has weakened further whilst heading north. Winds are down to 95kts, cat 2 on the SS scale. Shear continues to impinge on Halong. Further weakening is expected in the near term, but interestingly, JTWC forecast some re-intensification before landfall in Japan due to improved outflow into the mid-lattitude westerlies. Japan should see a landfalling typhoon of still significant strength in a few days time.

 

 

 

[Vorticity0123]

Japan should see a landfalling typhoon of still significant strength in a few days time.

 

Halong definitely remains a significant threat to Japan, espically rain-wise, even though the system has weakened somewhat. This is evident by weakened convection to the northwest of the system, also resulting in an open eyewall. Dvorak satellite imagery (as of 21:00 UTC) shows this:

 

Dvorak satellite imagery of Halong (Courtesy: NOAA)

 

Something that I find quite remarkable with Halong is the forecast uncertainty during its lifetime. During the first few days, the JTWC forecasted the system to move slowly toward the west-northwest and then to the north, while slowly intensifying to a category 2/3 storm (SSHS scale). However, Halong suddenly weakened due to shear, and it also appeared to move more to the west than anticipated. Thereafter, the rapid intensification into a category 5 storm was not forecast, as slow strengthening was anicipated (though it has to be said that such episodes are difficult to predict). Finally, Halong was anticipated to make landfall in the extreme western part of Japan, but that track forecast has been shifted significantly eastward. 

 

Note that the text written above is purely based on personal assessments, associated with jTWC forecast track history of Halong.

 

The current prognostic reasoning reflects this uncertainty:

 

 

 

BEYOND TAU 72, MODEL GUIDANCE HAS INCREASED SIGNIFICANTLY IN

VARIABILITY, LEADING TO A SHIFT TO THE CONSENSUS OF AVAILABLE MODEL

GUIDANCE. NVGM AND JENS HAVE SHIFTED WELL TO THE WEST FROM THE

PREVIOUS MODEL RUNS, AND BASED ON THE MODEL FIELDS, NVGM HAS TWO

STRS BUILDING ON THE EAST AND WESTERN PERIPHERIES LEADING TO A

PERIOD OF QUASI-STATIONARY MOTION BEYOND TAU 72. THIS FORECAST IS IN

BETTER ALIGNMENT WITH AVNO, BUT DOES NOT INCREASE TRACK SPEEDS AS

QUICKLY IN THE LATER TAUS AS AVNO SUGGESTS. LANDFALL WITH JAPAN IS

CURRENTLY ESTIMATED TO OCCUR BY TAU 96. 

 

 

Sources:

http://www.usno.navy.mil/JTWC/

http://www.ssd.noaa.gov/PS/TROP/floaters/11W/11W_floater.html

http://www.nrlmry.navy.mil/coamps-web/web/tc?&spg=&sid=11W&ddtg=2014080106

[Somerset Squall]

Halong has certainly been a difficult one to predict, at one point it looked like it was going to perhaps dissipate. Then it rapidly intensified in less than ideal levels of shear. Certainly an interesting one to watch, if not a forecasting nightmare!

 

Winds are down to 80kts according to JTWC. They still anticipate some slight re-intensification before landfall however.

[Somerset Squall]

Halong has re-strengthened to 90kts, cat 2 on the SS scale. Halong seems to be going through a rather lengthy eyewall replacement cycle, as concentric eyewalls have been evident for much of the day. Halong is crawling northwards towards Japan. It is forecast to roughly maintain it's intensity up until landfall east of Iwakuni, Japan.

[Somerset Squall]

Halong is nearing landfall at minimal typhoon intensity. The very long lived typhoon's life is nearly at an end as land interaction with Japan will severely weaken the system before it then begins extratropical transition. Japan is in for a pretty rough spell of weather from hereonin however.

Edited August 9, 2014 by Somerset Squall

[Buriedundersnow]

 Japan is in for a pretty rough spell of weather from hereonin however.

 

 

your not kidding.

 

BBC Weather â€@bbcweather 10m

Typhoon #HALONG: 528mm of rain in Funato during Saturday. Emergency weather warnings in force for Mie prefecture.

 

not far off 21 inches.

[Buriedundersnow]

Met Office Storms â€@metofficestorms 16m

Rain mounting up in southern Japan from Typhoon #Halong. Torigatayama has recorded 589 mm (23.2") in the last 24 hours.

[Nouska]

A collage of Halong and buddies on a wide angle view of the Pacific.