CPAC: ISELLE - Post-Tropical

[TropicalAnalystwx13]

Iselle has a very symmetrical central dense overcast, but convection isn't as deep as it could be (likely attributed to the cooling SSTs). As YE said, it's probably reaching peak intensity right now.

[supercane4867]

We may see 105kt or higher for next advisory as the eye is still clearing out



CI# /Pressure/ Vmax
5.9 / 952.7mb/112.4kt

Center Temp : +1.2C Cloud Region Temp : -62.7C

[Alyono]

the GFS based 12Z models have shifted a fair bit north of Hawaii

[TropicalAnalystwx13]

We may see 105kt or higher for next advisory as the eye is still clearing out



CI# /Pressure/ Vmax
5.9 / 952.7mb/112.4kt

Center Temp : +1.2C Cloud Region Temp : -62.7C

Yeah. This would have the opportunity to reach Category 4 status if eyewall convection was deeper, but SSTs are getting too cool for that.

Eye temperature up to +7.5C via CIMSS ADT.

[Kingarabian]

EYE warming means strengthening, no?

[Alyono]

yep... this does appear to have intensified slightly

[Yellow Evan]

EYE warming means strengthening, no?

Yep.

[Alyono]

EC has also shifted north, over Oahu and Kauai

[Yellow Evan]

EP, 09, 2014080318, , BEST, 0, 157N, 1332W, 100, 965, HU, 34, NEQ, 90, 90, 50, 70, 1012, 190, 15, 120, 0, E, 0, , 0, 0, ISELLE, D, 12, NEQ, 180, 180, 120, 180,
EP, 09, 2014080318, , BEST, 0, 157N, 1332W, 100, 965, HU, 50, NEQ, 40, 40, 20, 40, 1012, 190, 15, 120, 0, E, 0, , 0, 0, ISELLE, D, 12, NEQ, 180, 180, 120, 180,
EP, 09, 2014080318, , BEST, 0, 157N, 1332W, 100, 965, HU, 64, NEQ, 25, 20, 10, 20, 1012, 190, 15, 120, 0, E, 0, , 0, 0, ISELLE, D, 12, NEQ, 180, 180, 120, 180,

[Yellow Evan]

EC has also shifted north, over Oahu and Kauai

Do they dig the trough deeper?

0z GFS brings it near Maui.

[Alyono]

its still moving at about 275 then... not much of a trough would be present with that motion

[TheStormExpert]

Once again, another impressive E. Pacific hurricane.

[Yellow Evan]

Is it me or is Iselle starting to lose bands?

[Kingarabian]

The NHC has been reluctant to shift north as much as the models have. Maybe it's because they don't see Iselle being that strong the way the Euro and company do? Maybe it's because of its fast forward speed? I wonder if they change their stance.

[Kingarabian]

Is it me or is Iselle starting to lose bands?

It has been slowly losing bands since yesterday. The NHC alluded that Iselle going annular is a possibility. I think we're seeing the transition.

[hawaiigirl]

I'm getting a bit excited, nervous and scared all at the same time. Wondering if there is a chance this could hit Oahu as a cat 1, I don't think my house will take it very well.

[Kingarabian]

I'm getting a bit excited, nervous and scared all at the same time. Wondering if there is a chance this could hit Oahu as a cat 1, I don't think my house will take it very well.

I don't know about it reaching Hawaii as a cat. 1. Keep your eyes peeled though. Glad you're tracking this storm and aware.

[cycloneye]

HURRICANE ISELLE DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092014
200 PM PDT SUN AUG 03 2014

The cold cloud tops of Iselle's convection have suddenly begun to
expand during the past few hours, suggesting that vertical shear is
relaxing. The eye has become a little more distinct, and the
hurricane appears to be taking on a more circular, compact shape.
Current intensity estimates remain unchanged from earlier this
morning, so the initial intensity is held at 100 kt.

Regarding the compact shape of the hurricane, conventional and
microwave images seem to suggest that Iselle is losing its
convective banding features. And, for the first time, the Annular
Hurricane Index is indicating that Iselle has a marginal annular
structure. If it does in fact become annular, then the hurricane
is likely to only gradually weaken during the next couple of days
in an environment of light easterly shear and slowly decreasing sea
surface temperatures. Increasing vertical shear and even colder
waters should induce a faster weakening trend after 48 hours, but
most of the guidance still suggests that Iselle will maintain
tropical storm status as it moves near the Hawaiian Islands on days
4 and 5. The NHC intensity forecast is essentially unchanged from
the previous one and lies very close to the LGEM and intensity
consensus ICON for the entire forecast period.

The latest center fixes suggest that Iselle jogged west-
northwestward earlier today, but the estimated initial motion is
now westward, or 280/9 kt. The hurricane is expected to slow down
a little during the next 36 hours coincident with a developing
break in the subtropical ridge. A mid-level high is then forecast
to develop between Hawaii and California by day 3, which should
steer Iselle at a faster rate toward the west-northwest through the
end of the forecast period. There is very little spread among the
track models, but the entire envelope has shifted northward on days
3 through 5. Further shifts could be required if the models
continue their recent trends, but at this point Iselle is still a
potential threat to the Hawaiian Islands later this week.

FORECAST POSITIONS AND MAX WINDS

INIT 03/2100Z 15.7N 133.7W 100 KT 115 MPH
12H 04/0600Z 15.8N 135.1W 95 KT 110 MPH
24H 04/1800Z 15.8N 136.8W 90 KT 105 MPH
36H 05/0600Z 15.8N 138.3W 85 KT 100 MPH
48H 05/1800Z 16.0N 140.0W 75 KT 85 MPH
72H 06/1800Z 17.5N 145.0W 60 KT 70 MPH
96H 07/1800Z 19.5N 151.5W 50 KT 60 MPH
120H 08/1800Z 21.5N 157.5W 45 KT 50 MPH

$$
Forecaster Berg

[Kingarabian]

Eye continues to warm.

[CrazyC83]

Do any agencies have lower than T5.5? Otherwise the higher ADT would support 105 or 110 kt.