Hurricane MARIE

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HURRICANE MARIE DISCUSSION NUMBER  12
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132014
200 PM PDT SUN AUG 24 2014

Marie has developed a fairly steady-state structure, with a solid
area of white (in the Dvorak satellite enhancement) surrounding a 10
n mi wide eye.  Dvorak final-T numbers have risen to T7.0/140 kt
from TAFB, SAB, and the objective ADT, and that value is set as the
initial intensity.  This makes Marie the first category 5 hurricane
in the eastern North Pacific basin since Hurricane Celia in 2010.

Unless Marie can develop even colder cloud tops in the convection
surrounding the eye, continued strengthening is probably not
likely.  The SHIPS model shows additional intensification for the
next 12-18 hours, but much of the contribution comes from
persistence and not the environment itself.  Plus, a 1709 UTC AMSU
pass indicates that a secondary eyewall is already forming, making
it likely that an eyewall replacement will occur during the next
day or so.  Therefore, fluctuations in intensity are expected in
the short term, but the NHC intensity forecast keeps Marie as a
major hurricane through 48 hours.  After that time, the hurricane
will quickly move over colder water, and it is likely to weaken to
a tropical storm between day 3 and 4, and then become post-tropical
by day 5.  This scenario is not really different from the previous
forecast, except maybe showing a little faster weakening after 48
hours in line with the most recent SHIPS and LGEM guidance.

Trochoidal motions appear to be influencing Marie's recent short
term movement, but the hurricane's longer-term 12-hour motion is
270/12 kt.  The track guidance remains tightly clustered and
insists that Marie should resume a west-northwestward or even
northwestward motion in the next 12-24 hours.  That general
trajectory should continue through day 4, with Marie turning
north-northwestward by day 5 when it reaches the western edge of
the subtropical ridge.  As in the previous forecast, no significant
changes to the NHC track forecast were required on this advisory.

Although Marie is expected to remain well off the coast of Mexico,
very large swells will affect southwestern Mexico through tomorrow
and much of the Pacific coast of the Baja California peninsula
during the next few days.  Southerly swells will also reach the
coast of southern California by Tuesday, producing life-threatening
surf and rip currents, as well as minor coastal flooding.

FORECAST POSITIONS AND MAX WINDS

INIT  24/2100Z 16.0N 112.2W  140 KT 160 MPH
 12H  25/0600Z 16.6N 113.7W  140 KT 160 MPH
 24H  25/1800Z 17.9N 115.4W  135 KT 155 MPH
 36H  26/0600Z 19.5N 117.3W  120 KT 140 MPH
 48H  26/1800Z 20.7N 119.4W  105 KT 120 MPH
 72H  27/1800Z 23.0N 124.5W   70 KT  80 MPH
 96H  28/1800Z 26.0N 129.0W   45 KT  50 MPH
120H  29/1800Z 29.5N 131.5W   35 KT  40 MPH...POST-TROPICAL

$$
Forecaster Berg

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