Hurricane JULIO
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HURRICANE JULIO DISCUSSION NUMBER 17
NWS NATIONAL HURRICANE CENTER MIAMI FL EP102014
800 PM PDT THU AUG 07 2014
Despite a marginal environment, Julio has become better organized
over the past several hours with warming temperatures in the eye
and strong convection in the eyewall. Subjective and objective
Dvorak estimates from all agencies suggest that the intensity has
increased to at least 100 kt, so the initial wind speed is raised to
that value.
With few outer bands and a symmetric structure around the eye,
Julio now appears to have become an annular hurricane, much like
Iselle in the same general area a few days ago. While guidance
is generally showing a steady or quick weakening, these hurricanes
are known to be more resilent to marginal environments than most.
Since little change is expected to the SSTs or shear for the next
day or so, it makes sense to go above the model guidance at that
time with the current annular structure, and the NHC prediction is
raised from the previous one. An increase in westerly shear after
that time could cause Julio to transition into a more conventional
cyclone structure, so the intensity forecast is blended with the
previous interpolated forecast and the model consensus. At long
range, although the SSTs are forecast to rise, there could also be
an increase in shear. With the large uncertainty, little change is
made to the extended-range intensity prediction.
Julio is moving at about 280/14. There has been no change to the
forecast synoptic pattern with the hurricane expected to remain
south of the subtropical ridge for the next few days, with a
westward turn at long range due to the ridge strengthening. Track
guidance is in better agreement than the last cycle, with even
the GFDL model, formerly an outlier solution near Hawaii, shifting
northward away from the islands. The new NHC prediction is
adjusted a bit to the north at longer range, close to the model
consensus, although most of the better performing individual models
are still farther north. It should be noted that data from a NOAA
G-IV jet synoptic surveillance mission for Julio should be included
in the 0000 UTC model runs.
Julio is expected to move into the Central Pacific Hurricane
Center's area of responsibility by 0900 UTC and will issue the next
advisory on this system.
FORECAST POSITIONS AND MAX WINDS
INIT 08/0300Z 17.4N 139.1W 100 KT 115 MPH
12H 08/1200Z 17.8N 141.4W 100 KT 115 MPH
24H 09/0000Z 18.5N 144.3W 95 KT 110 MPH
36H 09/1200Z 19.4N 147.1W 85 KT 100 MPH
48H 10/0000Z 20.6N 149.9W 75 KT 85 MPH
72H 11/0000Z 22.9N 154.7W 65 KT 75 MPH
96H 12/0000Z 24.2N 159.2W 60 KT 70 MPH
120H 13/0000Z 25.0N 163.0W 60 KT 70 MPH
$$
Forecaster Blake
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