2015 CPAC Season

[Kingarabian]

12z Euro develops the first system mentioned above within 24 hours and then takes it really close to Hawaii missing from the east/

[Kingarabian]

CPHC needs to tag an invest asap. GFS and Euro have a depression within 24 hours.

[Kingarabian]

For the central north Pacific, between 140°W and 180.

1. A nearly stationary area of disturbed weather centered about 600 miles south of Honolulu Hawaii continues to produce poorly organized, but persistent, thunderstorms near the center. Upper level winds are expected to remain unfavorable for tropical cyclone development through Friday then become less hostile on Saturday.

* Formation chance through 48 hours, low, 30 percent.

2. Thunderstorm activity has increased in coverage today but remains poorly organized within a nearly stationary area of disturbed weather located about 1000 miles west-southwest of Honolulu Hawaii. The upper level environment is expected to remain unfavorable for tropical cyclone development through Friday then become less hostile on Saturday.

* Formation chance through 48 hours, low, 30 percent.

[Darvince]

Looks like they got up the invests just in time.

[Extratropical94]

A third area is up.

Showers and thunderstorms associated with a weak area of low pressure continue to develop around 1100 miles southeast of Hilo, Hawaii. Although these thunderstorms remain disorganized, environmental conditions will support some gradual organization over the next couple of days.

* Formation chance through 48 hours, low, near 0 percent.

[talkon]

06Z GFS predicts 5 CPAC storms in 16 days.

[Extratropical94]

3. Disorganized showers and thunderstorms associated with an area of low pressure continue to develop around 975 miles southeast of Hilo, Hawaii. Environmental conditions support some gradual organization over the next couple of days as it begins to drift northward.

* Formation chance through 48 hours, low, 20 percent.

[cycloneye]

Maybe a future development in this basin in the next few days? GFS is bullish but ECMWF does not.

[Kingarabian]

Maybe a future development in this basin in the next few days? GFS is bullish but ECMWF does not.

From what I see, I think models generally agree that there will be an area of low pressure forming in the CPAC within a couple of days.

Not sure if this is a ghost storm on the GFS's part. Development continues to come closer and closer with each run. Usually if it's a ghost storm, the development is always delayed with each run.

I'm 50-50 on it development. It is December... so of course you would lean against development. But it is a super El-Nino.

Also, the euro didn't do well with Sandra. We'll see.

[Ntxw]

Maybe this stir of westerly winds could kick up something of low latitude in the CPAC or EPAC?

[Kingarabian]

GFS, NOGAPS, and CMC all develop a disturbance in 2-3 days.

Edit: Why no mentions from the NHC or the CPHC?

[Yellow Evan]

They're usually really conservative out of season.

[Exalt]

I was checking some of the weather maps that I use that pull data from the GFS. The one that goes the farthest as far as hours/days for forecasts pins the development with a max winds of 70 mph (highest I could find within the system) and at 1003 mbar on Sunday December 13 at 10 AM.

However, afterwards during the day and Monday it showed it to get sheared apart (at least that's what I think was happening along the animation). Wouldn't be surprised to see this put as an invest around Wednesday and be upgraded to a depression later on.

Actual GFS models show it wobbling between 1002 and 1003 mbar at peak strength, shearing apart also forecasted.

(Pics of it as predicted for Sunday.)

[Darvince]

I don't know about you, but this looks pretty strong to me:

(from tropicaltidbits )

[Kingarabian]

Euro still showing nothing.

[Darvince]

The reason may lie in the fact that the GFS has the vortex which forms future Pali overpowers the other ones in the local area, sucking them all up and enabling enough energy for a tropical cyclone to form, while the Euro has the other areas of vorticity much weaker and becoming almost nonexistent within 96 hours instead of merging and forming a tropical cyclone. On the Euro, the vortex still exists but it fades out by the 7-day mark because of the lack of energy for it to get going.

[Exalt]

I don't know about you, but this looks pretty strong to me:
http://i.imgdiode.com/y5CreJ.png
(from tropicaltidbits )

Forecast must have shifted I guess. Now however, highest surface pressure forecasts are up to 989mb at peak strength for the 12z forecast at 132 hours.

[1900hurricane]

It might be worth noting that 99W has crossed into the CPac and could develop in the basin before year's end and/or crossing back into the WPac.

[Chris_in_Tampa]

Based on looking at the best track database, Tropical Depression Nine-C, which formed at 0Z on December 31st, is the southernmost forming depression on record north of the Equator in the Western Hemisphere. (in the Central North Pacific, Eastern North Pacific and North Atlantic basins)



Pictured: 06 UTC best track position on Dec. 31st of Tropical Depression Nine-C, at 2.4N 175.7W, with its previous track which includes points as a disturbance. Also included in the image are origin points of where tropical depressions formed in the Central North Pacific, since 1950, according to the National Hurricane Center's best track database. This image is cropped to show the Equator through the Tropic of Cancer. Additional depressions have originated further north of those pictured.

It is the "sixteenth tropical system of the year to either form within or pass through the Central North Pacific basin". (from CPHC discussion number 1 on Nine-C)

Advisories were initiated at 2.8N 177.8W, with the second advisory estimating the low-level circulation center to be at 2.5N 175.8W.

No tropical depression has ever formed south of 5N in this region. The previous record holder was Hurricane Ruby (02C) in 1972 which began as a depression at 5.0N 175.0W.

The best track positions before advisories were initiated have the disturbance originating at 0.6N and then dipping to 0.4N. (best track data is subject to revision)

The record holder for southernmost forming depression in the North Atlantic basin is Hurricane Isidore (10L) in 1990 at 7.2N. In the Eastern North Pacific it is Hurricane Adolph (01E) in 1983 at 7.1N. Depressions in the Western North Pacific Basin have formed closer to the equator than Nine-C.

Floater: http://www.ssd.noaa.gov/PS/TROP/floater ... oater.html
CPHC: http://www.prh.noaa.gov/cphc/