000
WTPA41 PHFO 270831
TCDCP1
Tropical Depression One-C Discussion Number 1
NWS Central Pacific Hurricane Center Honolulu HI CP012025
Issued by NWS National Hurricane Center Miami FL
1100 PM HST Sat Jul 26 2025
Deep convection has persisted over the area of low pressure well
southeast of the Hawaiian Islands for the last 12 hours or so, with
the latest satellite images showing improved organization and a
better defined banding structure. The latest subjective Dvorak
current intensity estimates came in at 2.0/30 knots from PHFO,
1.5/25 knots from SAB, and 1.0/25 knots from JTWC. A recent
27/0620Z Metop-B ASCAT pass showed a well-defined low-level
circulation with a large swath of 25-knot winds and a few embedded
25- to 30-knot wind barbs. Given the improved structure and
organization of the system, advisories are being initiated on the
first tropical cyclone of the season in the central Pacific,
Tropical Depression One-C. The initial intensity will be set at 30
knots.
Tropical Depression One-C is moving toward the west, or 270 degrees,
at 10 knots. This general westward motion is expected to continue
over the next couple of days as the system moves along the southern
periphery of a subtropical ridge to the north. Beyond 48 hours, the
forward speed is expected to increase considerably in response to a
low- to mid-level ridge strengthening to the north of cyclone. The
track forecast closely follows a blend of the TVCE and HCCA
consensus guidance.
The environment will remain conducive for intensification over the
next couple of days, as One-C remains over warm waters between 28
and 29C, with adequate mid-level moisture and light to moderate
easterly shear. As a result, the intensity forecast calls for
steady strengthening during this time, with One-C becoming Tropical
Storm Iona on Sunday. Beyond 60 hours, the cyclone will begin to
experience increasing westerly vertical wind shear while also
entraining drier mid-level air. This is expected to lead to steady
weakening, with the system becoming a tropical depression again
around day 5. The intensity forecast is best aligned with the HCCA
intensity consensus guidance.
FORECAST POSITIONS AND MAX WINDS
INIT 27/0900Z 10.9N 145.6W 30 KT 35 MPH
12H 27/1800Z 10.9N 146.7W 35 KT 40 MPH
24H 28/0600Z 11.2N 148.2W 40 KT 45 MPH
36H 28/1800Z 11.5N 150.0W 50 KT 60 MPH
48H 29/0600Z 11.5N 152.2W 50 KT 60 MPH
60H 29/1800Z 11.5N 154.8W 45 KT 50 MPH
72H 30/0600Z 11.7N 157.7W 40 KT 45 MPH
96H 31/0600Z 12.2N 164.7W 35 KT 40 MPH
120H 01/0600Z 12.9N 171.6W 30 KT 35 MPH...POST-TROP/REMNT LOW
$$
Forecaster Jelsema (CPHC)
https://i.imgur.com/r1N8Clj.png
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受到TUTT的影響 移入西太估計強度也不強
不過CPHC蠻看好他的強度
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GFS
https://i.imgur.com/jYEUlaO.png
ECMWF
https://i.imgur.com/YrbBSYM.png
谷歌
https://i.imgur.com/RXfrxPG.png

大旱？是要打「太早」嗎？！XDD