CPAC: ISELLE - Post-Tropical

[Kingarabian]

Convection has finally picked up from the west. I think if it manages to build some convection from the west it can then take off.

[cycloneye]

HURRICANE ISELLE DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092014
800 PM PDT FRI AUG 01 2014

Iselle's cloud pattern has increased in organization since the last
advisory, transitioning from a banding to an eye pattern. Cloud top
temperatures have also generally cooled in a small central dense
overcast that has recently formed. Though ragged and occasionally
obscured by high clouds, the 20 to 25 n mi diameter eye appeared
well defined in an earlier AMSR-2 microwave overpass. Satellite
intensity estimates were 3.5 and 4.0 from TAFB and SAB at 0000 UTC,
respectively, with the latest ADT CI values at 4.0. Based on these
data, the initial intensity is raised to 65 kt.

The initial motion estimate is 295/10. Iselle should move steadily
west-northwestward on the south side of a subtropical ridge until a
mid- to upper-level trough digging along 130W in 2-3 days causes the
ridge to weaken. Only a modest decrease in forward speed is
expected in at that time before the ridge re-strengthens over the
central Pacific by day 4, resulting in Iselle's moving faster
toward the west. The track guidance is tightly clustered through 2
days but diverges some after that time, with the guidance shifting
noticeably to the south at later times this cycle. The official
track has been nudged a bit south in the short term and southward
even more by days 3-5, but is not as far south as the multi-model
consensus TVCE.

Iselle is likely to continue to intensify during the next day or
two. The closed low-level ring of convection in microwave imagery
could portend a period of rapid intensification in the short term.
However, moderate north-northeasterly shear and marginal
thermodynamic parameters suggest this to be a lower probability
scenario. After about 2 days, sea surface temperature drop below
26.5C and the environment is expected to gradually become even
drier and more stable later in the forecast period. The shear
could also increase substantially by days 4-5 in association
with an upper-level trough, but this will depend on how far north
Iselle tracks. The intensity forecast is higher than the previous
one through about 2 days but is unchanged at later times,
representing a blend of the multi-model consensus and the FSU
Superensemble output.


FORECAST POSITIONS AND MAX WINDS

INIT 02/0300Z 14.7N 127.3W 65 KT 75 MPH
12H 02/1200Z 15.1N 128.7W 70 KT 80 MPH
24H 03/0000Z 15.5N 130.4W 75 KT 85 MPH
36H 03/1200Z 15.8N 132.3W 75 KT 85 MPH
48H 04/0000Z 16.2N 134.1W 75 KT 85 MPH
72H 05/0000Z 16.4N 137.0W 65 KT 75 MPH
96H 06/0000Z 16.5N 139.8W 60 KT 70 MPH
120H 07/0000Z 17.0N 144.5W 50 KT 60 MPH

$$
Forecaster Kimberlain

[Yellow Evan]

At this rate, we could see a Cat 2.

[Brent]

Is that Iselle near the Big Island of Hawaii? and look at what's behind it(it also hits Hawaii 4 days later)

[cycloneye]

HURRICANE ISELLE DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092014
200 AM PDT SAT AUG 02 2014

Satellite images indicate that Iselle continues to become better
organized during the past several hours with a ragged eye feature
present on the shortwave infrared channel. Microwave data also
show that the inner core has become better defined on the last
SSMI/S pass. There is quite a disparity, however, of current
satellite intensity estimates, ranging from 55 to 90 kt. Since the
cyclone appears somewhat better organized than 6 hours ago, the wind
speed is raised to 70 kt, but this estimate is more uncertain than
average.

Iselle has turned westward and appears to be moving 280/9,
although recently has wobbled due westward. The subtropical ridge
to the northwest of the cyclone should remain firm for the next
several days, continuing the general westward motion. There has been
a notable southward shift to most of the guidance overnight with
less influence now expected from a digging trough along 130W in a
couple of days. The ridge is expected to strengthen at long range,
causing a faster westward motion at that time. The new NHC track
forecast is shifted southward at all times, especially at Day 3 and
beyond, close to the model consensus.

Although Iselle has good inner core structure, a combination of
moderate northeasterly shear and decreasing SSTs is expected to
limit the chance for significant strengthening over the next couple
of days. However, the overall environment is not that unfavorable,
so little change in wind speed is forecast through 48 hours. After
that time, the cyclone will likely encounter drier air aloft,
marginal SSTs and more significant shear by Day 5, which should
cause weakening. The new forecast is kept very similar to the
previous forecast, which lies near the model consensus.



FORECAST POSITIONS AND MAX WINDS

INIT 02/0900Z 14.8N 128.4W 70 KT 80 MPH
12H 02/1800Z 15.0N 129.6W 75 KT 85 MPH
24H 03/0600Z 15.4N 131.4W 75 KT 85 MPH
36H 03/1800Z 15.7N 133.2W 75 KT 85 MPH
48H 04/0600Z 16.0N 134.8W 75 KT 85 MPH
72H 05/0600Z 16.0N 138.0W 70 KT 80 MPH
96H 06/0600Z 16.0N 141.5W 60 KT 70 MPH
120H 07/0600Z 16.5N 147.0W 45 KT 50 MPH

$$
Forecaster Blake

[Yellow Evan]

Is that Iselle near the Big Island of Hawaii? and look at what's behind it(it also hits Hawaii 4 days later)

Yes. It has 97E taking a similar path as well.

[Yellow Evan]

Second run of a 9080mbar TC or lower.



Should at least approach Hawaii

[Yellow Evan]

EP, 09, 2014080212, , BEST, 0, 149N, 1288W, 70, 987, HU, 34, NEQ, 70, 90, 50, 70, 1009, 180, 15, 0, 0, E, 0, , 0, 0, ISELLE, D,
EP, 09, 2014080212, , BEST, 0, 149N, 1288W, 70, 987, HU, 50, NEQ, 30, 30, 20, 40, 1009, 180, 15, 0, 0, E, 0, , 0, 0, ISELLE, D,
EP, 09, 2014080212, , BEST, 0, 149N, 1288W, 70, 987, HU, 64, NEQ, 20, 15, 0, 20, 1009, 180, 15, 0, 0, E, 0, , 0, 0, ISELLE, D,

[hurricanes1234]

Pressure dropped by 1 hPa.

000
WTPZ34 KNHC 021451
TCPEP4

BULLETIN
HURRICANE ISELLE ADVISORY NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092014
800 AM PDT SAT AUG 02 2014

...ISELLE MOVING WESTWARD WITH NO CHANGE IN STRENGTH...


SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...15.0N 129.2W
ABOUT 1370 MI...2205 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
ABOUT 1735 MI...2795 KM E OF HILO HAWAII
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES


WATCHES AND WARNINGS
--------------------
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 800 AM PDT...1500 UTC...THE CENTER OF HURRICANE ISELLE WAS
LOCATED NEAR LATITUDE 15.0 NORTH...LONGITUDE 129.2 WEST. ISELLE IS
MOVING TOWARD THE WEST NEAR 10 MPH...17 KM/H. A WEST TO WEST-
NORTHWESTWARD MOTION AT A SIMILAR FORWARD SPEED IS EXPECTED DURING
THE NEXT 48 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 80 MPH...130 KM/H...WITH HIGHER
GUSTS. ONLY SLIGHT STRENGTHENING IS FORECAST DURING THE NEXT DAY OR
SO.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 25 MILES...35 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 105
MILES...165 KM.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB...29.15 INCHES.


HAZARDS AFFECTING LAND
----------------------
NONE


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...200 PM PDT.

$$
FORECASTER BERG

[Yellow Evan]

000
WTPZ44 KNHC 021451
TCDEP4

HURRICANE ISELLE DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092014
800 AM PDT SAT AUG 02 2014

Iselle has maintained an eye during the past several hours, but the
deepest convection has been unable to persist within the western
eyewall. According to UW-CIMSS shear analyses, about 15 kt of
north-northeasterly shear is affecting the hurricane, and a recent
TRMM pass indicated that the mid-level center is displaced about
10-15 n mi south of the low-level center. The maximum winds are
still estimated to be 70 kt based on Dvorak estimates of T4.5/77 kt
from SAB and T4.0/65 kt from TAFB.

Moderate vertical shear is expected to persist for another 12 hours
or so and then become negligible between 24-72 hours. Even though
sea surface temperatures are expected to stay near or just above
26C through the next 5 days, oceanic heat content is forecast to
drop significantly in about 24-36 hours. Therefore, mixing and
upwelling of colder water is likely to limit significant additional
strengthening. The intensity models are in good agreement in
showing Iselle leveling off around 75 kt during the next couple of
days, and the official forecast maintains that scenario. Cooler
ocean water and increased shear are expected to cause weakening
beyond day 3.

Iselle is located to the south of a mid-level ridge, which is
steering the hurricane westward with an initial motion of 280/9 kt.
A mid-level shortwave trough is still expected to develop to the
north of Iselle in about 48 hours, but its only real effect will be
to weaken the steering flow for a day or two. After day 3,
mid-level ridging is forecast to restrengthen to the north and
northeast of Iselle, causing the cyclone to accelerate westward by
the end of the forecast period. There continues to be some
latitudinal spread in the track guidance, especially on days 4 and
5. The updated NHC track forecast is very near the previous
forecast and the model consensus TVCE for the sake of continuity.

FORECAST POSITIONS AND MAX WINDS

INIT 02/1500Z 15.0N 129.2W 70 KT 80 MPH
12H 03/0000Z 15.2N 130.5W 75 KT 85 MPH
24H 03/1200Z 15.6N 132.4W 75 KT 85 MPH
36H 04/0000Z 15.9N 134.2W 75 KT 85 MPH
48H 04/1200Z 16.0N 135.9W 75 KT 85 MPH
72H 05/1200Z 16.0N 139.0W 70 KT 80 MPH
96H 06/1200Z 16.0N 143.0W 60 KT 70 MPH
120H 07/1200Z 16.5N 148.5W 45 KT 50 MPH

$$
Forecaster Berg

[Yellow Evan]

[cycloneye]

Hey,recon is going next Thursday!

II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK.....NEGATIVE.
3. ADDITIONAL DAY OUTLOOK: FIX HURRICANE ISELLE NEAR
16N 143W AT 06/1200Z.

[Kingarabian]

Hey,recon is going next Thursday!

II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK.....NEGATIVE.
3. ADDITIONAL DAY OUTLOOK: FIX HURRICANE ISELLE NEAR
16N 143W AT 06/1200Z.

First time since 09.

[Kingarabian]

SAB/TAFB at 4.5.

ADT at 5.0.

Still lacks deep convection in the western eyewall however.

[CrazyC83]

With those data yet the shallow convection, probably 75 kt is the best estimate - on the lower end.

[Kingarabian]

[supercane4867]

Solid Cat.2

TXPZ24 KNES 021832
TCSENP

A. 09E (ISELLE)

B. 02/1800Z

C. 15.0N

D. 129.5W

E. ONE/GOES-W

F. T5.0/5.0/D1.5/24HRS

G. IR/EIR/VIS

H. REMARKS...DG EYE IS EMBEDDED IN...AND SURROUNDED BY...LG WHICH RESULTS
IN A DT OF 5.0. PT IS 5.0. MET IS 5.0 BASED ON RAPID DEVELOPMENT OVER
THE LAST 24 HOURS. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...TURK

[Yellow Evan]

EP, 09, 2014080218, , BEST, 0, 150N, 1296W, 85, 976, HU, 64, NEQ, 20, 15, 10, 20, 1009, 180, 15, 105, 0, E, 0, , 0, 0, ISELLE, D,

Iselle has hit the RI. Here we go again.

[Yellow Evan]

Looks great.

[cycloneye]

Cat 2.


HURRICANE ISELLE DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092014
200 PM PDT SAT AUG 02 2014

Despite continued north-northeasterly shear, Iselle has strengthened
to category 2 strength during the past few hours. The deep
convection remains a little asymmetric, favoring the eastern
semicircle, but Dvorak estimates have still risen to T4.5/77 kt from
TAFB and T5.0/90 kt from SAB and the UW-CIMSS ADT. These data,
combined with an earlier AMSU estimate of 78 kt, support raising the
initial intensity to 85 kt.

The vertical shear, such as it is, is still expected to diminish
during the next 12-24 hours. At the same time, Iselle will be
moving over decreasing oceanic heat content values, and the stronger
winds will likely lead to increased upwelling of colder water. The
official forecast allows for a little more intensification in the
short term, but after 24 hours the less favorable thermodynamic
environment should induce gradual weakening. The updated NHC
intensity forecast is a little bit higher than the previous one only
during the first 3 days to account for the higher initial intensity.
Beyond day 3, the GFDL and HWRF keep Iselle near the threshold of
hurricane intensity while the statistical models show a more marked
decrease in winds. The NHC intensity forecast is very close to the
LGEM and FSU Superensemble on days 4 and 5.

Iselle's initial motion is 280/8 kt. The hurricane is expected to
maintain a general westward motion but could slow down a bit in
48-72 hours when the ridge to the north of Iselle weakens. By days
4 and 5, a mid-level high northeast of Hawaii is anticipated to
strengthen and slide eastward, which should impart a faster westward
motion at the end of the forecast period. The track guidance is
tightly clustered during the first 72 hours, but most of the models,
particularly the ECMWF and GFDL, have shifted northward on this
cycle. The updated NHC track forecast is also nudged northward on
days 4 and 5 and lies close to the FSU Superensemble.

FORECAST POSITIONS AND MAX WINDS

INIT 02/2100Z 15.1N 130.1W 85 KT 100 MPH
12H 03/0600Z 15.4N 131.5W 90 KT 105 MPH
24H 03/1800Z 15.7N 133.5W 90 KT 105 MPH
36H 04/0600Z 15.9N 135.4W 85 KT 100 MPH
48H 04/1800Z 16.0N 137.0W 80 KT 90 MPH
72H 05/1800Z 16.0N 140.0W 75 KT 85 MPH
96H 06/1800Z 16.5N 144.5W 60 KT 70 MPH
120H 07/1800Z 17.5N 150.5W 45 KT 50 MPH

$$
Forecaster Berg