Hurricane RACHEL
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HURRICANE RACHEL DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL EP182014
200 PM PDT SAT SEP 27 2014
An eye has become more persistent in geostationary imagery during
the past few hours, and cloud top temperatures have cooled in the
convective ring surrounding the eye. Dvorak estimates from TAFB and
SAB were both T4.0 at 1800 UTC, and the initial intensity is set to
65 kt, making Rachel the 12th hurricane of the eastern North Pacific
season. The cyclone does not have much time to strengthen further,
given that it will be moving over gradually cooler waters and into a
drier and more stable environment during the next day or so.
Weakening is forecast to begin by 24 hours, and continue through the
remainder of the period given the aforementioned unfavorable
conditions and a forecast increase in shear. The cyclone should
weaken to a remnant low in about 3 days. The NHC intensity forecast
is similar to the previous one and is close to the IVCN intensity
consensus.
The initial motion is now toward the north-northwest or 335/07.
Rachel is forecast to gradually turn northward by 24 hours as it
moves into a weakness in the subtropical ridge. Then, the decaying
cyclone will be caught in a region of weak steering currents, and
little net motion is expected on days 2 and 3. After that time, the
remnant low should move southwestward as it comes under the
influence of a low-level ridge over the northeastern Pacific. There
continues to be considerable spread in the track model guidance
beyond 24 to 36 hours, but the NHC forecast remains close to the
previous official forecast and is not too far from the TVCE
multi-model consensus.
The initial 34-kt wind radii have been adjusted based on an ASCAT
pass around 18Z.
FORECAST POSITIONS AND MAX WINDS
INIT 27/2100Z 20.3N 116.5W 65 KT 75 MPH
12H 28/0600Z 21.1N 116.8W 65 KT 75 MPH
24H 28/1800Z 22.0N 117.0W 60 KT 70 MPH
36H 29/0600Z 22.3N 117.1W 55 KT 65 MPH
48H 29/1800Z 22.2N 117.3W 45 KT 50 MPH
72H 30/1800Z 21.7N 117.6W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 01/1800Z 20.8N 118.3W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 02/1800Z 19.8N 119.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
$$
Forecaster Brennan
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