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Another off season tropical depression has formed, this time about 400 miles east-northeast of Chuuk. 02W has winds of 25kts according to JTWC. The depression has some modest convection over the LLCC, with some curved banding features wrapping in. 02W is forecast to strengthen, as shear is low to moderate, waters warm (for now) and outflow good. JTWC expect a peak of 60kts before shear rises and waters cool along track.

The track forecast is uncertain and fairly complex. Currently, motion is slow due to competing steering influences, between a ridge to the northeast and another to the northwest. The northeastern ridge is currently favoured to win out, allowing an eventual acceleration in speed northwestwards. Thereafter, there is disagreement in the models, with some forecasting a recurve northeast, and others forecasting a westward turn. JTWC favours the recurve scenario in a few days time.

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The track forecast is uncertain and fairly complex. Currently, motion is slow due to competing steering influences, between a ridge to the northeast and another to the northwest. The northeastern ridge is currently favoured to win out, allowing an eventual acceleration in speed northwestwards. Thereafter, there is disagreement in the models, with some forecasting a recurve northeast, and others forecasting a westward turn. JTWC favours the recurve scenario in a few days time.

attachicon.gifwp0215.gif

 

What a dfference a day can make regarding forecast track. The JTWC has made a major shift in their forecast track, now indicating a northwestward motion. For comparison, the two forecast tracks are given below:

 

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Yesterday's forecast track from JTWC

 

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Today's forecast track from JTWC

 

The 5-day position has been shifted by almost 15 degrees longitude, which equals about 4500 km! Such large shifts in forecast track are rarely seen.

 

If one takes a look at the GFS ensemble spread, one can easily understand the amount of difficulity the JTWC has had so far with this system:

 

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GFS ensemble forecast tracks for Higos (20 runs), from the 00Z 08-02 run.

 

With such huge spread, I am happy not to be a hurricane forecaster :D

 

 

Sources:

http://www.movable-type.co.uk/scripts/latlong.html

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

http://rammb.cira.colostate.edu/products/tc_realtime/storm.asp?storm_identifier=WP022015

http://ruc.noaa.gov/tracks/

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Indeed Vorticity, a forecasting nightmare!

One thing is clear however, Higos is strengthening. Winds are up to 55kts according to JTWC. Convection has significantly deepened over the LLCC and strong banding features continue to wrap in. JTWC expect Higos to briefly become a typhoon before shear begins to weaken the storm.

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Higos has become a 65kt typhoon according to JTWC, the second off season typhoon of the year. Higos has a solid central dense overcast with multiple banding features wrapping into the circulation. Higos has also not started moving northwestwards yet, meaning it has a little more time over warm water and under relatively low shear. JTWC now expect a peak if 85kts (cat 2 on the SS Scale), which is impressive for a system in February.

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Higos has continued to strengthen quickly. Winds are at 85kts according to JTWC, a cat 2 on the SS scale. JMA have also upgraded Higos to a typhoon using the 10-min sustained wind estimate.

Interestingly, this makes Higos the earliest second typhoon on record.

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Wow! The next JTWC advisory should be interesting! Higos has developed a clear eye overnight, and is definitely looking the best it has ever done so far!

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Wow! The next JTWC advisory should be interesting! Higos has developed a clear eye overnight, and is definitely looking the best it has ever done so far!

 

Impressive, Higos has been defying the odds thus far! The JTWC have upped the intensity of Higos to 105 knots (1 minute mean), making the cyclone a major hurricane on the SSHS scale. Their forecast now calls for the cyclone to become a category 4 hurricane (120 kt), which is quite unusual for cyclones so early in the season. Below is a Dvorak satellite image loop of Higos, nicely showing the formation of the eye of the cyclone:

 

 

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Dvorak satellite loop of Higos. Click on the image to activate the loop.

 

The last few frames show that the cyclone is becoming slightly more ragged, as its eye becomes slightly becomes slightly less defined. This could indicate that Higos has peaked in intensity.

 

CIMSS MIMIC imagery also beautifully shows the formation of the eyewall of Higos:

 

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CIMSS MIMIC imagery loop of Higos. Click on the image to activate it.

 

The image is slightly fragmented, most likely caused by satellite issues.

It has to be said, though, that the eyewall of Higos does seem to be very well organized in the image so far.

 

After the next 12 hours, Higos is forecast to weaken rapidly while recurving to the northeast due to increasing shear and dry air entrainment, eventually dissipating in the mid-latitude westerlies.

 

Interestingly, this makes Higos the earliest second typhoon on record.

 

That is indeed quite interesting, especially since the South Pacific and the Australian basin are very calm regarding tropical cyclone activity so far.

 

Sources:

http://www.ssd.noaa.gov/PS/TROP/floaters/02W/02W_floater.html

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

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

 

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Unless I am mistaken, I think Higos may be the second strongest February typhoon on record going by 1-min JTWC estimates. If it does reach 120kt, it will be tied with Typhoon Nancy of 1970 for strongest, obviously any stronger and it will take the record. A rare beast for February!

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It is quite amazing really, and fortunate Higos has kept clear of populated areas. Meantime this side of the equator has been very docile for a quite a while. But next week may change with a TC expected to develop near Christmas Island and another in the Gulf of Carpentaria. The monsoon trough has re-established itself along the north coast and things will likely quieten down north of the equator.

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What a difference 12 hours makes. Higos is weakening, and fast, as shear and dry air impact the system. Winds have decreased to 85kts at the last JTWC update, but I expect they will be lot lower next update, as the LLCC is now becoming exposed from the convection, a far cry from the well defined eye embedded in a central dense overcast this morning.

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What a difference 12 hours makes.

 

And another 12 hours later, Higos is close to be declared a remnant low! This cyclone is weakening even faster than it spun up just a day ago. Take a look at the latest Dvorak satellite image of Higos below:

 

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Dvorak satellite image of Higos.

 

The LLCC (low level circulation center) is indicated by the black cross.

As one can see, the LLCC is exposed to the west of a weakening area of convection. Most likely, this convection has been blown away by about 25 kt of west-southwesterly shear.

 

Another surprise is that Higos has moved to the west-northwest instead of recurving toward the northeast, most likely caused by the rapid weakening.

 

The JTWC now forecasts Higos to dissipate in about 36 hours after curving slightly back to the northeast. I would not be surprised if the JTWC issues their final advisory by today.

 

Sources:

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

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

http://www.ssd.noaa.gov/PS/TROP/floaters/02W/02W_floater.html

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Confirmation: the JTWC has issued their last advisory on Higos as it has weakened to a tropical depression with 25 kt winds and has become devoid of convection.

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