000
WTPZ33 KNHC 300247
TCPEP3

BULLETIN
HURRICANE JIMENA ADVISORY NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL EP132015
800 PM PDT SAT AUG 29 2015

…POWERFUL JIMENA MOVING SLIGHTLY FASTER TOWARD THE WEST-
NORTHWEST…
SUMMARY OF 800 PM PDT…0300 UTC…INFORMATION
———————————————-
LOCATION…13.3N 127.5W
ABOUT 1330 MI…2140 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS…140 MPH…220 KM/H
PRESENT MOVEMENT…WNW OR 290 DEGREES AT 13 MPH…20 KM/H
MINIMUM CENTRAL PRESSURE…945 MB…27.91 INCHES
WATCHES AND WARNINGS
——————–
There are no coastal watches or warnings in effect.
DISCUSSION AND 48-HOUR OUTLOOK
——————————
At 800 PM PDT (0300 UTC), the center of Hurricane Jimena was located
near latitude 13.3 North, longitude 127.5 West. Jimena is
moving slightly faster toward the west-northwest near 13 mph (20
km/h), and this motion is expected to continue for the next couple
of days.

Maximum sustained winds remain near 140 mph (220 km/h) with higher
gusts. Jimena is a category 4 hurricane on the Saffir-Simpson
Hurricane Wind Scale. Fluctuations in intensity are possible
during the next day or so, but Jimena is expected to remain a major
hurricane through Monday.

Hurricane force winds extend outward up to 35 miles (55 km) from the
center and tropical storm force winds extend outward up to 125 miles
(205 km).

The estimated minimum central pressure is 945 mb (27.91 inches).
HAZARDS AFFECTING LAND
———————-
None.
NEXT ADVISORY
————-
Next complete advisory at 200 AM PDT.

$$
Forecaster Kimberlain

WTPZ43 KNHC 300251
TCDEP3

HURRICANE JIMENA DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL EP132015
800 PM PDT SAT AUG 29 2015

Jimena continues to undergo an eyewall replacement, with significant
inner-core structural changes seen in satellite data throughout
the day. Microwave images show a small inner eyewall rotating
around an irregularly-shaped outer eyewall at about 60 n mi radius,
the latter which could be slowly contracting. Although Jimena’s
cloud pattern has fluctuated some during this period of inner-core
change, its overall organization has remained about the same
since the last advisory. Satellite classifications seem to bear
this out, with intensity estimates of T6.0/115 kt and T6.5/127 kt
from SAB and TAFB, respectively, at 0000 UTC. These are blended
with the latest UW-CIMSS ADT value of 6.1/117 kt to keep the initial
intensity estimate at 120 kt.

The intensity forecast is challenging. The large-scale environment
is forecast to remain relatively favorable during the next day or
two, apart from some north-northwesterly shear associated with a
cold low to the northeast of Jimena. This could allow an
opportunity for reintensification if the current eyewall
replacement fully plays out, but predicting intensity fluctuations
due to inner-core dynamics is nearly impossible and beyond the
scope of this forecast. Thus, a slow decrease in intensity is
indicated in the new forecast as large-scale conditions only
gradually become less conducive. This is a blend of the
statistical-dynamical guidance. As Jimena gradually gains latitude
later in the forecast period, global models show a minor increase in
westerly shear while other thermodynamic factor remain generally
neutral, except for slowly decreasing SSTs. These factors suggests
a slow decay of the cyclone, and the new intensity forecast is in
agreement with the latest multi-model consensus that shows a
monotonic decrease in intensity from days 3 to 5.

The eye of Jimena has been wobbling quite a bit, but smoothing
through these yields a faster initial motion estimate of 295/11.
Jimena should continue moving west-northwestward during the next few
days as it approaches the western end of a subtropical ridge around
140W. A weakness in the ridge around this longitude should induce a
significant deceleration by days 4 and 5. The track guidance is in
excellent agreement through the first 2 days, with less-than-typical
spread beyond that time. The new track forecast is faster and
adjusted slightly southward and then westward after day 3, but not
as far south or west as the multi-model consensus.
FORECAST POSITIONS AND MAX WINDS

INIT 30/0300Z 13.3N 127.5W 120 KT 140 MPH
12H 30/1200Z 13.9N 129.3W 115 KT 130 MPH
24H 31/0000Z 14.7N 131.8W 110 KT 125 MPH
36H 31/1200Z 15.4N 134.4W 110 KT 125 MPH
48H 01/0000Z 16.0N 136.7W 105 KT 120 MPH
72H 02/0000Z 16.9N 139.9W 95 KT 110 MPH
96H 03/0000Z 17.6N 141.9W 85 KT 100 MPH
120H 04/0000Z 18.1N 143.4W 75 KT 85 MPH

$$
Forecaster Kimberlain