Hurricane NORBERT

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HURRICANE NORBERT DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP142014
800 AM PDT SAT SEP 06 2014

First visible images reveal a pinhole eye surrounded by very deep
convection. Nevertheless, after a rapid intensification observed on
satellite last night, objective and subjective Dvorak T-numbers are
decreasing, and only support an initial intensity of 100 kt. A
portion of the circulation is already reaching cooler waters and
moving into a more stable environment. This should result in a
gradual weakening during the next 24 hours, with a faster rate of
weakening thereafter. Norbert is expected to become a remnant low
over the cold waters just west of the northern Baja California
peninsula in 3 days or so.

The best estimate of the initial motion is toward the northwest or
310 degrees at 7 knots. Norbert is forecast to be steered by the
flow around the southwestern periphery of a mid-level ridge
centered over the southwestern United States. In a 48 hours, the
cyclone will reach the base of the mid-latitude westerlies and
will begin to move northward and then northeastward. By then,
Norbert is forecast to be a shallow cyclone, moving little
in a weak low-level flow. There is high confidence in the short-
term track forecast since there is a good guidance agreement. Beyond
3 days, global models either forecast Norbert to dissipate in situ
near the west coast of the northern Baja California peninsula or
continue to move the system eastward as a weak low or a trough. The
NHC prefers the former global model solution.

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  06/1500Z 25.0N 114.1W  100 KT 115 MPH
 12H  07/0000Z 25.6N 115.1W   80 KT  90 MPH
 24H  07/1200Z 26.5N 116.4W   65 KT  75 MPH
 36H  08/0000Z 27.3N 117.3W   50 KT  60 MPH
 48H  08/1200Z 28.2N 117.8W   40 KT  45 MPH
 72H  09/1200Z 29.5N 117.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  10/1200Z 30.0N 116.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  11/1200Z 30.0N 116.0W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Avila

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