CPAC: JULIO - Post-Tropical

[cycloneye]

HURRICANE JULIO
FLIGHT ONE -- NOAA 49
A. 08/0000Z
B. NOAA9 0110C JULIO
C. 07/1730Z
D. NA
E. NA
F. 41,000 TO 45,000 FT

SUCCEEDING DAY OUTLOOK:
BEGIN 6-HRLY FIXES ON JULIO AT 09/0530Z.
A POSSIBLE G-IV MISSION DEPARTING PHNL AT 08/1730Z
FOR HURRICANE JULIO.

[South Texas Storms]

12z GFS brings Julio much closer to the islands.

[Yellow Evan]

12z GFS brings Julio much closer to the islands.

As a hurricane too

[Yellow Evan]

EP, 10, 2014080618, , BEST, 0, 156N, 1311W, 65, 989, HU, 34, NEQ, 50, 50, 60, 90, 1010, 210, 15, 0, 0, E, 0, , 0, 0, JULIO, D,
EP, 10, 2014080618, , BEST, 0, 156N, 1311W, 65, 989, HU, 50, NEQ, 30, 30, 30, 30, 1010, 210, 15, 0, 0, E, 0, , 0, 0, JULIO, D,
EP, 10, 2014080618, , BEST, 0, 156N, 1311W, 65, 989, HU, 64, NEQ, 15, 15, 15, 15, 1010, 210, 15, 0, 0, E, 0, , 0, 0, JULIO, D,

[cycloneye]

HURRICANE JULIO DISCUSSION NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL EP102014
200 PM PDT WED AUG 06 2014

Satellite imagery shows that Julio has become a little better
organized, with multiple convective bands near the center and
an eye possibly trying to form. The latest SSM/IS overpass,
though, suggests the eyewall is still open to the north. The
satellite intensity estimates from TAFB and SAB are 77 kt and
65 kt, so the initial intensity remains at a possibly-conservative
65 kt. The cirrus outflow remains good over the southwestern
semicircle and poor elsewhere.

The initial motion is now 290/15, which is a little to the right of
the previous advisory. The NHC model guidance is in good agreement
on Julio moving along the southern periphery of a deep-layer ridge
to its north for the next 72 hours or so. After that, a weakness in
the ridge is forecast to develop north of the Hawaiian Islands, and
Julio is expected to turn more northwestward. Based on current
trends, Julio is likely to be a little north of the previous
forecast during the first 48 hours or so. However, at the later
times the dynamical models have shifted southward since their
previous forecasts, with the most notable shift by the GFS. The
consensus models and the center of the guidance envelope have also
shifted southward at 96-120 hours. The new track forecast will
also be adjusted southward at those times, but it lies a little to
the north of the consensus models. The NOAA G-IV jet is currently
flying a synoptic surveillance mission for Hurricane Iselle, and
this data is also expected to help subsequent forecasts of Julio.

The dynamical models have come into reasonably good agreement that
Julio will remain in a light vertical wind shear environment through
the forecast period. Thus, the intensity is most likely going to be
controlled by sea surface temperatures and nearby dry air. While
Julio is moving over gradually decreasing sea surface temperatures,
some additional strengthening is possible during the next 12 hours
or so. After that, the cyclone is expected to traverse sea surface
temperatures of 25C-26C and gradually move into a drier air mass.
This should cause a gradual weakening for the rest of the forecast
period. The new intensity forecast is adjusted slightly from the
previous forecast and is in best agreement with the intensity
consensus. It should be noted that despite the marginal sea surface
temperatures and moisture, none of the dynamical models forecast
Julio to dissipate during the next 5 days. Indeed, the GFDL and
HWRF are stronger than the current forecast at 96-120 hours.


FORECAST POSITIONS AND MAX WINDS

INIT 06/2100Z 15.8N 131.8W 65 KT 75 MPH
12H 07/0600Z 16.3N 134.2W 70 KT 80 MPH
24H 07/1800Z 16.9N 137.4W 70 KT 80 MPH
36H 08/0600Z 17.4N 140.3W 70 KT 80 MPH
48H 08/1800Z 18.0N 143.3W 65 KT 75 MPH
72H 09/1800Z 19.5N 148.5W 60 KT 70 MPH
96H 10/1800Z 21.5N 154.0W 55 KT 65 MPH
120H 11/1800Z 24.5N 158.5W 50 KT 60 MPH

$$
Forecaster Beven

[Yellow Evan]

EP, 10, 2014080700, , BEST, 0, 162N, 1324W, 70, 986, HU, 34, NEQ, 60, 60, 60, 80, 1010, 210, 15, 0, 0, E, 0, , 0, 0, JULIO, D,
EP, 10, 2014080700, , BEST, 0, 162N, 1324W, 70, 986, HU, 50, NEQ, 30, 30, 30, 30, 1010, 210, 15, 0, 0, E, 0, , 0, 0, JULIO, D,
EP, 10, 2014080700, , BEST, 0, 162N, 1324W, 70, 986, HU, 64, NEQ, 15, 15, 15, 15, 1010, 210, 15, 0, 0, E, 0, , 0, 0, JULIO, D,

[CrazyC83]

I think the cool wake from Iselle might hold Julio back a bit...but it only takes one spurt of RI'ing.

[Yellow Evan]

I think the cool wake from Iselle might hold Julio back a bit...but it only takes one spurt of RI'ing.

The air is more moist due to Iselle though so it goes both ways.

[cycloneye]

HURRICANE JULIO DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL EP102014
800 PM PDT WED AUG 06 2014

Julio has strengthened during the last several hours. The eye of
the hurricane, which is quite distinct in microwave images, has
recently become apparent in infrared satellite images. In addition,
the convective pattern is more symmetric about the center than it
was earlier today. The initial wind speed is raised to 75 kt, using
a blend of the latest Dvorak estimates from TAFB, SAB, and UW-CIMSS
ADT.

The hurricane is currently over sea surface temperatures of about
27 C, and in an atmosphere of low shear and relatively high
moisture. Therefore, some additional strengthening is possible
during the overnight hours. After that time, however, Julio is
expected to cross the 26 C isotherm and should remain over 25-26 C
water for the next few days. These cool waters combined with a
drier air mass should cause the system to slowly weaken.

The initial motion estimate is about the same as before, 290/14. A
deep-layer ridge to the north of Julio is expected to keep the
system moving westward to west-northwestward for the next few days.
Beyond that time, the models are in fairly good agreement in
showing a break in the ridge developing due to a large trough
moving eastward over the north Pacific. This change in the
steering pattern should cause Julio to turn more toward the
northwest in 4 to 5 days. The track guidance has changed little
this cycle, and the NHC forecast is largely an update of the
previous one. Based on the latest forecast, Julio will be near or
to the north of the Hawaiian Islands this weekend.

FORECAST POSITIONS AND MAX WINDS

INIT 07/0300Z 16.4N 133.2W 75 KT 85 MPH
12H 07/1200Z 16.9N 135.5W 80 KT 90 MPH
24H 08/0000Z 17.4N 138.6W 80 KT 90 MPH
36H 08/1200Z 17.9N 141.5W 75 KT 85 MPH
48H 09/0000Z 18.5N 144.5W 70 KT 80 MPH
72H 10/0000Z 20.3N 150.0W 60 KT 70 MPH
96H 11/0000Z 22.8N 155.4W 55 KT 65 MPH
120H 12/0000Z 25.5N 160.5W 50 KT 60 MPH

$$
Forecaster Cangialosi

[Alyono]

0Z GFS has landfall in Kauai from the east

[TheStormExpert]

Surprised that they haven't shifted the track further south with the models like the GFS showing a landfall in Hawaii.

[Alyono]

I can see Iselle striking the BIG ISLAND from the east, but Kauai?

[supercane4867]

The ridge quickly rebuild to its north in this run

[somethingfunny]

I think the cool wake from Iselle might hold Julio back a bit...but it only takes one spurt of RI'ing.

[Yellow Evan]

Looks like a borderline Cat 2. Here we go again.

[supercane4867]

00z ECMWF shifts even further north...

[Alyono]

the EC run is junk. It also takes Iselle well north of the Big Island

[supercane4867]

...JULIO STRENGTHENS TO A CATEGORY 2 HURRICANE...

2:00 AM PDT Thu Aug 7
Location: 16.8°N 134.9°W
Moving: WNW at 17 mph
Min pressure: 976 mb
Max sustained: 100 mph

[meriland23]

Looks far more defined and condensed now with a good eye forming.

[cycloneye]

HURRICANE JULIO DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL EP102014
200 AM PDT THU AUG 07 2014

Julio's signature in infrared satellite imagery has improved since
the last advisory. The hurricane is compact and symmetric, and the
eye has cleared out during the past few hours. Satellite intensity
estimates have all increased and are now T5.0/90 kt from TAFB,
T4.5/77 kt from SAB, and T5.2/95 kt from the UW-CIMSS ADT. A blend
of these data supports increasing the winds to 85 kt on this
advisory.

The forward speed has increased a bit to 290/15 kt. Julio is
expected to remain south of the subtropical ridge for the next few
days, which will keep it on a westward to west-northwestward
trajectory. Global model fields are now indicating that a break in
the ridge currently to the north of Hawaii may fill in just enough
over the next few days to keep Julio from turning northwestward at
the end of the forecast period. The track guidance is tightly
clustered for the first 48 hours. After that time, the ECMWF model
is a noticeable outlier compared to the rest of the models, showing
Julio taking a more northern route as it is steered around a more
strongly depicted mid-level high northeast of Hawaii. The updated
NHC forecast is largely unchanged from the previous one and lies
just to the northeast of the multi-model consensus TVCE after 72
hours.

Julio is essentially straddling the 26C sea surface temperature
isotherm and is expected to move over water between 25-26C during
the next 3 days or so. Even though water temperatures are
marginal for strengthening, Julio has a few other factors going for
it. Vertical shear is expected to remain light for another 2 days,
and Julio appears to be embedded within a much larger moisture
envelope than Iselle has had to work with. In addition, Julio's
fast motion may help to mitigate the negative influence of
upper-ocean mixing of cooler waters. Therefore, the NHC intensity
forecast allows for the possibility of further strengthening during
the next 12 hours or so and keeps Julio at hurricane strength for
the next 2-3 days. Only gradual weakening is anticipated at the end
of the forecast period since Julio will be moving over increasingly
warmer waters to the north and west of Hawaii.

FORECAST POSITIONS AND MAX WINDS

INIT 07/0900Z 16.8N 134.9W 85 KT 100 MPH
12H 07/1800Z 17.2N 137.2W 90 KT 105 MPH
24H 08/0600Z 17.7N 140.3W 85 KT 100 MPH
36H 08/1800Z 18.3N 143.2W 80 KT 90 MPH
48H 09/0600Z 19.0N 146.1W 75 KT 85 MPH
72H 10/0600Z 21.0N 151.5W 60 KT 70 MPH
96H 11/0600Z 23.5N 156.5W 55 KT 65 MPH
120H 12/0600Z 25.0N 161.0W 50 KT 60 MPH

$$
Forecaster Berg