CPAC: JULIO - Post-Tropical

[cycloneye]

TROPICAL STORM JULIO DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL EP102014
200 PM PDT TUE AUG 05 2014

Satellite imagery this afternoon indicates that Julio is becoming
better organized, with increased convective banding and cloud tops
colder than -80C near the center. Satellite intensity estimates are
55 kt and 45 kt from TAFB and SAB respectively. In addition, an
earlier CIMSS AMSU estimate was 53 kt. Based on these data, the
initial intensity is increased to 55 kt.

The initial motion is now 280/12. A low/mid-level ridge to the
north of the cyclone should steer it westward to west-northwestward
with some increase in forward speed during the next 3-4 days.
After that, the dynamical models forecast the ridge to weaken,
which would cause Julio to move more northward. The track guidance
envelope is similar to the previous guidance through 72 hours, and
this part of the forecast is an update of the previous forecast.
From 72-120 hours, the guidance envelope has shifted significantly
to the north. The new forecast track is also shifted northward,
but it still lies to the south of the consensus models and all of
the dynamical models except the GFDL/NAVGEM. If the current model
trends continue, an additional northward adjustment may be
necessary in later advisories. It should be noted that the NOAA
G-IV jet is currently flying a synoptic surveillance mission for
Hurricane Iselle, and the data from this mission will hopefully
help the subsequent forecasts for Julio.

Julio is now in a light vertical wind shear environment, and the
dynamical models suggest this will continue through the forecast
period. However, the forecast track takes the system over
gradually decreasing sea surface temperatures during the next 48
hours. The consensus of the intensity guidance is for continued
strengthening for the next 36-48 hours, and the increased banding
seen during the last few hours could be the start of a faster
intensification rate. The new intensity forecast continues to call
for a peak intensity of 75 kt, and at this time only the
HFIP-sponsored University of Wisconsin model forecasts a higher peak
intensity. After 48 hours, gradual weakening is expected as the
center moves along the 26C isotherm and this part of the new
forecast is in best agreement with the SHIPS model.


FORECAST POSITIONS AND MAX WINDS

INIT 05/2100Z 14.2N 126.0W 55 KT 65 MPH
12H 06/0600Z 14.7N 128.2W 60 KT 70 MPH
24H 06/1800Z 15.4N 131.4W 65 KT 75 MPH
36H 07/0600Z 16.0N 134.4W 75 KT 85 MPH
48H 07/1800Z 16.6N 137.3W 75 KT 85 MPH
72H 08/1800Z 17.5N 143.0W 70 KT 80 MPH
96H 09/1800Z 19.0N 148.5W 60 KT 70 MPH
120H 10/1800Z 21.0N 153.0W 60 KT 70 MPH

$$
Forecaster Beven

[Yellow Evan]

Could become a hurricane tonight.

[cycloneye]

RI going on?

[Kingarabian]

RI going on?

Looks like it. We went from a zero eye like future, to one that's peeking in less than 2 hours.

Code: Select all

       CI# /Pressure/ Vmax
                3.6 / 994.2mb/ 57.0kt

     
             Final T#  Adj T#  Raw T#
                3.5     4.0     4.4

ADT numbers have jumped.



I think we could see a special advisory if it continues.

[Yellow Evan]

RI going on?

Possibly. If so, here we go again.

[fci]

Does significant track change to North lessen threat to Hawaii?

[Cyclenall]

When I first saw Julio doing the wrap-around (clenched fist as its known on here), I was skeptical that it would complete to become a RI'ing TC. The deep convection was fragmented on the curving band so that's why I wasn't sure. Now an eye is popping out really fast so it appears Julio is pulling a Bud from '06.

[cycloneye]

Not a hurricane yet.

EP, 10, 2014080600, , BEST, 0, 142N, 1268W, 55, 994, TS

[cycloneye]

TROPICAL STORM JULIO DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL EP102014
800 PM PDT TUE AUG 05 2014

After a decrease in the overall thunderstorm activity earlier today,
a new burst of deep convection has redeveloped near the center. The
outflow remains fair in all quadrants suggesting that there is
little wind shear over the cyclone. Based on satellite estimates
from TAFB and SAB of T3.5 on the Dvorak scale, the initial
intensity is been kept at 55 knots. Given the current structure in
both conventional satellite and microwave data, as well as the
prevailing low shear, it is very likely that Julio will reach
hurricane status within the next 6 to 12 hours. Some additional
strengthening is then forecast. However, despite the
expected light shear, the strengthening will be limited by the
cooler ocean ahead of Julio, and the NHC forecast calls for
weakening beyond 36 hours. This is consistent with the intensity
models which have an upper intensity limit of 80 knots by the
SHIPS model.

The best estimate of the initial motion is 285 degrees at 13 knots.
Julio is well embedded within the easterly flow around the periphery
of the subtropical ridge. Global models keep a strong ridge to
the north of the cyclone for the next 2 to 3 days, and forecast some
slight erosion of the western portion of the ridge thereafter. This
pattern should keep Julio on a general west-northwest track through
the forecast period. Although the NHC forecast is similar to
the previous one, it has been adjusted slightly northward to be
consistent with the multi-model consensus TVCE and be more centered
within the guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT 06/0300Z 14.4N 127.5W 55 KT 65 MPH
12H 06/1200Z 14.9N 129.8W 65 KT 75 MPH
24H 07/0000Z 15.5N 133.0W 70 KT 80 MPH
36H 07/1200Z 16.3N 136.0W 75 KT 85 MPH
48H 08/0000Z 17.0N 139.0W 70 KT 80 MPH
72H 09/0000Z 18.0N 144.5W 60 KT 70 MPH
96H 10/0000Z 20.0N 149.5W 50 KT 60 MPH
120H 11/0000Z 22.0N 154.0W 45 KT 50 MPH

$$
Forecaster Avila

[bahamaswx]

Way too pretty to be a TS.

[Yellow Evan]

[Alyono]

GFS seems to have shifted west. I suspect the models will come back to the west because Iselle may be destroyed over the Big Island, which will result in less turning of Julio. Models did this with Iselle when they were forming the phantom west of Hawaii the last couple of days

[Yellow Evan]

GFS seems to have shifted west. I suspect the models will come back to the west because Iselle may be destroyed over the Big Island, which will result in less turning of Julio. Models did this with Iselle when they were forming the phantom west of Hawaii the last couple of days

Hence this increases the threat to Hawaii. Not good.

[supercane4867]

...JULIO STRENGTHENS INTO THE FIFTH HURRICANE OF THE 2014 EASTERN NORTH PACIFIC SEASON...

2:00 AM PDT Wed Aug 6
Location: 14.8°N 129.0°W
Moving: WNW at 17 mph
Min pressure: 989 mb
Max sustained: 75 mph

Interesting part of 2AM discussion:

The initial motion estimate is 285/15 kt based on a blend of
conventional and microwave satellite fixes. The NHC model guidance
remains in excellent 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 break in the ridge is forecast to develop north
of the Hawaiian Islands on Days 4 and 5, and Julio is expected to
turn more northwestward, passing just north of the Islands. However,
the new model runs, which have incorporated the 0000 UTC NOAA G-IV
jet dropsonde data are not showing as much erosion of the ridge as
in previous runs, and the response has been a slight southward shift
of the track guidance at 96 and 120 hours. The official forecast
track is just an update of the previous advisory track through 72
hours, and was shifted slightly southward after that, similar to the
consensus model TVCE, but not as far south as the ECMWF model. The
latter model brings Julio much closer to the Hawaiian Islands since
it no longer develops a break in the ridge.

[Kingarabian]

...JULIO STRENGTHENS INTO THE FIFTH HURRICANE OF THE 2014 EASTERN NORTH PACIFIC SEASON...

2:00 AM PDT Wed Aug 6
Location: 14.8°N 129.0°W
Moving: WNW at 17 mph
Min pressure: 989 mb
Max sustained: 75 mph

Interesting part of 2AM discussion:

The initial motion estimate is 285/15 kt based on a blend of
conventional and microwave satellite fixes. The NHC model guidance
remains in excellent 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 break in the ridge is forecast to develop north
of the Hawaiian Islands on Days 4 and 5, and Julio is expected to
turn more northwestward, passing just north of the Islands. However,
the new model runs, which have incorporated the 0000 UTC NOAA G-IV
jet dropsonde data are not showing as much erosion of the ridge as
in previous runs, and the response has been a slight southward shift
of the track guidance at 96 and 120 hours. The official forecast
track is just an update of the previous advisory track through 72
hours, and was shifted slightly southward after that, similar to the
consensus model TVCE, but not as far south as the ECMWF model. The
latter model brings Julio much closer to the Hawaiian Islands since
it no longer develops a break in the ridge.

ECMWF kills Iselle over the big island of Hawaii. GFS passes it to the south of the island. That'll be key for it.

[Cyclenall]

Even though this became a hurricane, the wrap-around from yesterday didn't quite sustain the eye and it ended up bursting over the center again so I consider that a failed attempt afterall. Right after said attempt it looks ragged but the motion near the center looks vigorous so the next try at an eye lasting should be shortly.

[Yellow Evan]

000
WTPZ45 KNHC 060851
TCDEP5

HURRICANE JULIO DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL EP102014
200 AM PDT WED AUG 06 2014

A small burst of deep convection with cloud tops of -75C to -80C has
developed over the low-level center, resulting in the formation of a
central dense overcast feature. In addition, passive microwave
satellite imagery has been indicating a 75-100 percent closed low-
to mid-level eye feature since about 0100 UTC. Satellite intensity
estimates are a consensus T4.0 from TAFB and SAB, so the initial
intensity has been increased to 65 kt, making Julio the fifth
hurricane of the 2014 eastern North Pacific season.

The initial motion estimate is 285/15 kt based on a blend of
conventional and microwave satellite fixes. The NHC model guidance
remains in excellent 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 break in the ridge is forecast to develop north
of the Hawaiian Islands on Days 4 and 5, and Julio is expected to
turn more northwestward, passing just north of the Islands. However,
the new model runs, which have incorporated the 0000 UTC NOAA G-IV
jet dropsonde data are not showing as much erosion of the ridge as
in previous runs, and the response has been a slight southward shift
of the track guidance at 96 and 120 hours. The official forecast
track is just an update of the previous advisory track through 72
hours, and was shifted slightly southward after that, similar to the
consensus model TVCE, but not as far south as the ECMWF model. The
latter model brings Julio much closer to the Hawaiian Islands since
it no longer develops a break in the ridge.

The developing eye feature, low shear of less than 5 kt, and a
moistening mid-troposphere argue for at least some modest
strengthening for the next 36 hours or so as Julio moves from a SST
cold pool and over a warmer oceanic ridge. These condition also
typically favor rapid intensification, which would be a possibility,
except for the occasional intrusions of cooler and more stable air
from the north. However, it wouldn't be surprising if Julio
reaches its peak intensity a little sooner than forecast while the
upper-level outflow pattern continues to expand. By 48 hours, the
cyclone will be moving over cooler waters and into a more stable air
mass, which should induce gradual weakening. The official intensity
forecast is a little higher than the previous advisory and the
consensus model ICON.

FORECAST POSITIONS AND MAX WINDS

INIT 06/0900Z 14.8N 129.0W 65 KT 75 MPH
12H 06/1800Z 15.4N 131.4W 70 KT 80 MPH
24H 07/0600Z 16.1N 134.5W 75 KT 85 MPH
36H 07/1800Z 16.7N 137.5W 80 KT 90 MPH
48H 08/0600Z 17.3N 140.4W 75 KT 85 MPH
72H 09/0600Z 18.5N 145.9W 65 KT 75 MPH
96H 10/0600Z 20.4N 151.1W 55 KT 65 MPH
120H 11/0600Z 23.0N 156.0W 50 KT 60 MPH

$$
Forecaster Stewart

[HurricaneTracker2031]

Julio should be passing from Northeast of Hawaii as a weakening Tropical Storm due to cooler waters ahead. Nevertheless, people who reside in Hawaii should monitor the progress of Julio.

Julio RGB Imagery [Unsaved Loop]


Synopsis of Julio and other systems: http://goo.gl/B6qAmu

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[cycloneye]

HURRICANE JULIO DISCUSSION NUMBER 11
NWS NATIONAL HURRICANE CENTER MIAMI FL EP102014
800 AM PDT WED AUG 06 2014

Julio has a somewhat ragged appearance in satellite imagery this
morning. While cloud tops near the center are about -80C, AMSR-2
microwave imagery a few hours ago showed that the eyewall was open
to the north. That, combined with a large arc cloud seen moving
northward away from the center, suggests that dry air entrainment is
occurring on the north side. Satellite intensity estimates are 77
kt from TAFB and 65 kt from SAB. Given the current appearance, the
initial intensity remains 65 kt. The cirrus outflow is good over
the southwestern semicircle and poor elsewhere.

The initial motion is still 285/15, and there is no change to the
forecast philosophy from 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 break in the ridge is forecast to develop north
of the Hawaiian Islands, and Julio is expected to turn more
northwestward and pass north of the Islands. There is some spread
in the guidance by 96-120 hours. The ECMWF, UKMET, and GFDL are on
the south side of the guidance envelope forecasting a track closer
to Hawaii, while the GFS, GFS Ensemble Mean, and Canadian models are
on the right side of the guidance envelope. The center of the
envelope and the consensus models are very close to the previous
forecast, and thus the new forecast track is almost identical to the
previous forecast.

Julio is in an environment of light vertical wind shear, and it
should remain over sea surface temperatures of 26C or warmer for the
next 12-24 hours. This should allow some strengthening if the
storm can fight off the current dry air intrusion. After that, the
cyclone is forecast to move over sea surface temperatures of
25C-26C, which should cause some weakening. There is disagreement
in the dynamical models about how much shear Julio should encounter
while over the cooler water, particularly near the Hawaiian
Islands. The UKMET forecasts stronger shear, while the GFS/ECMWF are
forecasting less shear. The intensity forecast leans toward the
GFS/ECMWF scenario and thus calls for Julio to slowly weaken after
36 hours. The new forecast has minor adjustments from the previous
and is similar to the intensity consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 06/1500Z 15.2N 130.5W 65 KT 75 MPH
12H 07/0000Z 15.7N 132.8W 70 KT 80 MPH
24H 07/1200Z 16.4N 135.9W 75 KT 85 MPH
36H 08/0000Z 17.0N 138.9W 75 KT 85 MPH
48H 08/1200Z 17.7N 141.9W 70 KT 80 MPH
72H 09/1200Z 19.0N 147.5W 60 KT 70 MPH
96H 10/1200Z 21.0N 152.5W 55 KT 65 MPH
120H 11/1200Z 24.0N 157.5W 50 KT 60 MPH

$$
Forecaster Beven

[hurricanes1234]

I doubt this will intensify much more, if at all. It's been taking quite a while to strengthen and has little time left.