ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM

HURRICANE NORBERT DISCUSSION NUMBER  19
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP142014
800 PM PDT SAT SEP 06 2014

The cloud pattern of Norbert has degraded significantly over the
past few hours. The eye is no longer apparent, and in fact there is
no deep convection north of the center where SSTs are below 26C.
Satellite intensity estimates continue to decrease, and the initial
intensity of 75 kt is based on the latest UW-CIMSS ADT estimate and
the Dvorak estimate from SAB. Rapid weakening is expected to
continue during the next 24 hours, as the cyclone will move over
colder waters and into a drier and more stable environment. Norbert
should then weaken more slowly to remnant low status in 2 to 3 days
over the cold waters west of the northern Baja California peninsula.
The new NHC intensity forecast is close the latest IVCN multi-model
consensus.

Norbert has jogged a bit to the left over the past few hours, with
an initial motion estimate of 300/07. The synoptic reasoning for the
track forecast remains unchanged. Norbert will be steered around the
southwestern periphery of a mid-level ridge centered over the
southwestern United States, which should result in a turn toward the
north-northwest by 24 hours. By 48 hours, Norbert should turn
northward as it moves into a break in the ridge at the base of a
mid-latitude trough off the U.S. West Coast. A slow northeastward
motion is shown late in the period as the shallow cyclone will be
embedded in weak low-level flow. The new NHC track is similar to the
previous one adjusted for the initial position and motion.

The 34-kt wind radii have been adjusted inward based on data from a
recent ASCAT-B pass.

Moisture from the remnants of Dolly and the Pacific ITCZ is being
advected northward by the outer circulation of Norbert across
northern Mexico and into the southwestern United States. This could
result in heavy rains and life-threatening flash flooding in these
areas during the next few days. Please see information from your
local weather office for more details.

FORECAST POSITIONS AND MAX WINDS

INIT  07/0300Z 25.5N 115.5W   75 KT  85 MPH
 12H  07/1200Z 25.9N 116.3W   60 KT  70 MPH
 24H  08/0000Z 26.9N 117.0W   45 KT  50 MPH
 36H  08/1200Z 27.9N 117.6W   35 KT  40 MPH
 48H  09/0000Z 28.8N 117.6W   30 KT  35 MPH
 72H  10/0000Z 29.7N 116.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  11/0000Z 30.0N 116.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  12/0000Z...DISSIPATED

$$
Forecaster Brennan

NNNN