(Weather Guru)
Fri Aug 16 2013 06:43 PM
Central Pacific Gets Hyperactive

The normally peaceful Central Pacific has all of a sudden become a hotbed of tropical activity, with 3 areas of interest currently ongoing. One is already a named storm, Pewa, one is a strong invest (90C) and one is a dying former East Pac invest.

Tropical Storm Pewa formed early today about 1300 miles SW of Honolulu and is moving W at 14 mph with 40 mph winds. It looks quite healthy on satellite with nice outflow and persistent deep convection over the center. The forecast takes it west to WNW through the next five days which should keep it north of the Marshall Islands, although the northernmost islands are in the cone. It is expected to peak at around 60 mph before hitting shear ahead of a ULL and weakening. Pewa should cross into the JTWC's area of responsibility sometime later tomorrow. Pewa is the first system to get a name from the Central Pacific list since Omeka in December of 2010.

A few hundred miles ENE of Pewa is Invest 90C. Yesterday it appeared this was the more likely system to develop (80% chance at one point) until Pewa decided to steal the show. The outflow from Pewa is imparting shear on 90C which is hampering development. Still on satellite you can see a good amount of spin and if Pewa moves a little farther away this might have a chance to develop (currently a 30% chance).

Last (and least) to the S of the Big Island is a disturbed area which is getting sheared apart by the outflow from the two aforementioned systems and probably will cease to exist before long (0% chance).

(Weather Guru)
Mon Aug 19 2013 06:16 PM
Re: Central Pacific Gets Hyperactive

So after going about 32 months without seeing a system form in the Central Pacific basin we have now had 3 systems (!) form in the last 4 days. I haven't checked but my guess is one would have to go back a long way in the history books to find the last time 3 systems formed in 4 days.

Tropical Storm Unala formed last night out of what was Invest 90C, bypassing TD status to become a TS. Its main problem was that it formed too close to TS Pewa (less than 300 miles) and the stronger Pewa quickly drew Unala into its circulation and absorbed it.

Then today we had TD Three-C develop a few hundred miles farther east. This is the one that was south of the Big Island on Friday and looked dead in the water and was even dropped for a time from the TWO, but sprang back to life over the weekend and has maintained persisistent deep convection near the center despite fairly strong westerly shear. The official forecast calls for the shear to win out and Three-C is not expected to be named, but the way things are going, I wouldn't count it out.

Southeast of the Big Island there is another tropical wave that has been given a 10% chance of development. It looks pretty anemic currently but conditions may improve in a couple days, if it lasts that long.

As for Pewa it appeared to be going through a rapid intensification phase yesterday and became a typhoon for a time, but it ran into a strong ULL to its northwest and the southerly shear has weakened it today back to a strong TS. Having to absorb TS Unala might have disrupted it as well. The shear is expected to lessen in about 36 hours and Pewa should intensify as it moves NW.

In case anyone's counting this now makes 6 classifiable systems so far in the Central Pacific basin (counting Gil, Henriette and Flossie which came over from the EPAC) which pulls it one ahead of the Atlantic basin's 5 storms. Who woulda thunk it!

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