HURRICANE GEORGETTE DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL EP082016
800 PM PDT SUN JUL 24 2016
Georgette has been rapidly intensifying. The eye of the hurricane
has become much more distinct in satellite images since the previous
advisory, and the deep convection is fairly symmetric around the
center. The latest Dvorak estimates from TAFB, SAB, and CIMSS at
the University of Wisconsin support raising the initial intensity to
115 kt, making Georgette a category 4 hurricane on the Saffir-
Simpson Hurricane Wind Scale. This is an impressive 50-kt intensity
increase in the past 24 hours. Even though Georgette is a major
hurricane, scatterometer data from a few hours ago indicated that
its wind field is fairly compact.
Georgette has been taking advantage of favorable environmental
conditions of very low shear and sufficiently warm waters of about
27 deg C during its rapid intensification phase. Although the shear
is expected to remain light during the next few days, Georgette is
forecast to track over progressively cooler SSTs and it should cross
the 26 deg C isotherm in about 12 hours. Therefore, some additional
strengthening is possible overnight, but a steady weakening trend
should commence on Monday. Georgette is forecast to become a
post-tropical cyclone in 3 to 4 days when it is expected to be
embedded in a dry air mass and located over SSTs of 22-23 deg C.
The hurricane is moving northwestward at about 10 kt toward a
weakness in the subtropical ridge caused by an upper-level low. This
general heading with a decrease in forward speed is expected during
the next couple of days. After that time, a faster motion toward
the west-northwest and then west is forecast when the weakening
system becomes steered by the low-level trade wind flow. The NHC
track forecast is not too different from the previous one, and lies
close to the multi-model consensus.
HURRICANE GEORGETTE DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL EP082016
800 PM PDT SAT JUL 23 2016
Georgette's convective structure improved this evening, as a band
of showers and thunderstorms wrapped more than 360 degrees around
the center. The intensity estimates spanned a wide range: 55 kt
from SAB Dvorak, 58 kt from CIMSS AMSU, 65 kt from TAFB Dvorak, and
75 kt from CIMSS ADT. A blend of these gives 65 kt, making
Georgette a hurricane. A 2227Z CIRA AMSU size analysis indicated
that the tropical cyclone remained small with tropical-storm-force
winds extending out only to 60 nm in the northern semicircle.
Continued steady intensification is expected, but only for another
day or so while Georgette traverses over warm SSTs, through moist
unstable air, and experiences low tropospheric vertical shear.
Starting on Monday, it is anticipated that the thermodynamics will
no longer be conducive and gradual to steady weakening should
occur. Around day four, the combination of cold SSTs and a dry
stable atmosphere may lead to the system losing its deep convection
and becoming a post-tropical cyclone. The NHC intensity forecast
shows a slightly higher peak intensity in a day, then indicates a
quicker demise. This forecast is based on a blend of the HWRF
dynamical hurricane model and the LGEM statistical technique.
Georgette is moving toward the west at about 8 kt, in the mid-level
easterlies associated with the subtropical ridge to its north. An
upper-level low swings around to the western periphery of Georgette
and helps to induce a more northerly component of motion to the
hurricane between 36 and 72 h. By day four, a decaying Georgette is
steered back toward the west-northwest in the low-level trade winds.
The NHC track forecast is nearly the same as that from the previous
advisory and is based upon the TVCE multi-model consensus.
Georgette is the fourth hurricane to form during the month of July
in the eastern North Pacific basin. This ties a record for the
month of July, last equaled back in 1992.
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