CPAC: ISELLE - Post-Tropical

[Yellow Evan]

It's already north of South Point

I think you are being fooled by the northerly shear over the system pushing the convection south (and the fact that the nrothern radar is out is not exactly helping anyways). The surface center remains on track

Probs, I don't have the best of skill when locating centers.

[TheAustinMan]

WRF at 2:00 HST August 8. By this time I believe the model has the system west of the Big Island.

[AdamFirst]

http://khon2.com/live-stream/

KHON is streaming wall to wall coverage with plenty of local perspective and reports from the big island.

[Yellow Evan]

what data does CPHC have to lower the winds? Just to raise them again once the plane gets back there at 6Z?

I'm not expecting them too either.

[Alyono]

where did TWC get the 5 PM HST advisory from already?

TWC saying CPHC lowered the winds

[CrazyC83]

I'd be tempted to go 75 kt with the improved core.

[Alyono]

Just fixed this at only 70 miles offshore now

[Yellow Evan]

where did TWC get the 5 PM HST advisory from already?

TWC saying CPHC lowered the winds

ATCF is at 70 knts, adv is not out. This could be an error.

[AFWeather]

WTPA43 PHFO 080231
TCDCP3

HURRICANE ISELLE DISCUSSION NUMBER 32
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092014
500 PM HST THU AUG 07 2014

ISELLE IS BARELY HOLDING ON TO HURRICANE STATUS. ALTHOUGH THE
MINIMUM CENTRAL PRESSURE CONTINUES TO GRADUALLY RISE...THE
RECONNAISSANCE AIRCRAFT FOUND MAXIMUM FLIGHT LEVEL WINDS OF 72
KNOTS TO THE NORTHEAST OF THE CENTER AT 2300 UTC. THE HIGHEST SFMR
WINDS WERE 68 KNOTS...AND VARIOUS WIND REDUCTION TECHNIQUES RESULTED
IN MAXIMUM SUSTAINED SURFACE WIND ESTIMATES BETWEEN 65 AND 70 KNOTS.
THE 00Z SYNOPTIC INTENSITY WAS THUS KEPT AT 70 KNOTS...BUT GIVEN
THE INCREASINGLY RAGGED APPEARANCE IN THE SATELLITE IMAGERY...THE
ADVISORY INTENSITY WILL BE 65 KNOTS FOR THIS CYCLE.

EVEN THOUGH THE TRACK FORECAST TAKES ISELLE OVER INCREASINGLY WARM
SEA SURFACE TEMPERATURES...THE CYCLONE WILL BE ENTERING A HOSTILE
ENVIRONMENT IN REGARDS TO SHEAR. ISELLE IS CONTINUING TO IMPINGE ON
STRONGER NORTHERLIES AT THE EASTERN PERIPHERY OF AN UPPER
ANTICYCLONE LOCATED NEAR JOHNSTON ISLAND. THE SHEAR...ALONG WITH
INTERACTION OF THE CORE WITH THE BIG ISLAND TERRAIN...WILL RESULT IN
MORE RAPID WEAKENING DURING THE NEXT 24 HOURS. STRONG SHEAR WILL
PERSIST THROUGH MUCH OF THE FORECAST PERIOD AS AN UPPER LEVEL LOW
DIGS SOUTHWARD OVER THE NORTHWEST HAWAIIAN ISLANDS. THE INTENSITY
FORECAST HAS BEEN ADJUSTED DOWNWARD TO ACCOUNT FOR THESE FACTORS...
AND IS ON THE LOWER END OF THE GUIDANCE ENVELOPE. AS HAS BEEN STATED
BEFORE...REGARDLESS OF WHETHER ISELLE MAKES IT TO THE BIG ISLAND AS
A MINIMAL HURRICANE OR TROPICAL STORM...THERE WILL BE SIGNIFICANT
IMPACTS FROM WIND...RAIN...AND SURF.

THE TRACK FORECAST HAS BEEN NUDGED JUST SLIGHTLY SOUTHWARD AFTER 12
HOURS TO ACCOUNT FOR THE EXPECTATION OF A SHALLOWER CYCLONE. ISELLE
IS MOVING WEST-NORTHWEST TO THE SOUTH OF A RATHER WEAK SUBTROPICAL
RIDGE ROUGHLY ALONG LATITUDE 39N. THIS RIDGE IS FORECAST TO SINK
SOUTH...BUT WEAKEN...WHICH SHOULD RESULT IN A SLOWER FORWARD MOTION
WITH ISELLE IN A COUPLE OF DAYS. SOME ACCELERATION OF ISELLE...OR
ITS REMNANT LOW...IS FORECAST AT THE LONGER TIME PERIODS AS THE
SUBTROPICAL RIDGE TO THE NORTH OF THE SYSTEM STRENGTHENS.


FORECAST POSITIONS AND MAX WINDS

INIT 08/0300Z 19.1N 153.8W 65 KT 75 MPH
12H 08/1200Z 19.4N 156.1W 55 KT 65 MPH
24H 09/0000Z 19.8N 158.8W 50 KT 60 MPH
36H 09/1200Z 20.3N 161.3W 40 KT 45 MPH
48H 10/0000Z 20.6N 163.3W 35 KT 40 MPH
72H 11/0000Z 21.6N 167.8W 30 KT 35 MPH
96H 12/0000Z 23.5N 173.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 13/0000Z 26.4N 179.8E 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
R BALLARD

[Alyono]

CPHC does seem to give weight to Dvorak estimates even when recon is present... the Dvorak numbers have been falling so this wouldn't surprise me

[Yellow Evan]

Just fixed this at only 70 miles offshore now

When would you expect landfall?

[Alyono]

Increasingly ragged? Give me a break!

[Yellow Evan]

This is a big mistake IMO. There's nothing to suggest it's weakened much.

I'd rather give it 75 knts than 65 knts.

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[Alyono]

Now... this does NOT mean it cannot weaken before landfall a little.

However, this close to the coast, and the fact recon is heading in, one should wait for the data before adjusting the winds. What happens if recon finds 70-75 kt winds. Only makes CPHC look foolish

This is why I'd rather the specialists at NHC handle this, not a WFO office that does not routinely handle TCs

[tallywx]

http://khon2.com/live-stream/

KHON is streaming wall to wall coverage with plenty of local perspective and reports from the big island.

Watching now. This stuff is must-see TV. So local, so Hawaii.

"KHON-TV's newscasts have been the highest-rated in Hawaii for almost 40 years"

[Kingarabian]

Why on mother earth would you give weight to Dvorak when you have ground proof. This is the second time they've done this.

[Equilibrium]

http://khon2.com/live-stream/

KHON is streaming wall to wall coverage with plenty of local perspective and reports from the big island.

Thanks for posting the link excellent information on the big picture atm.

[galaxy401]

Now... this does NOT mean it cannot weaken before landfall a little.

However, this close to the coast, and the fact recon is heading in, one should wait for the data before adjusting the winds. What happens if recon finds 70-75 kt winds. Only makes CPHC look foolish

This is why I'd rather the specialists at NHC handle this, not a WFO office that does not routinely handle TCs

Is there another recon mission underway? I thought the previous one was possibly the last one.

[Alyono]

Now... this does NOT mean it cannot weaken before landfall a little.

However, this close to the coast, and the fact recon is heading in, one should wait for the data before adjusting the winds. What happens if recon finds 70-75 kt winds. Only makes CPHC look foolish

This is why I'd rather the specialists at NHC handle this, not a WFO office that does not routinely handle TCs

Is there another recon mission underway? I thought the previous one was possibly the last one.

I THINK the next one will reach the storm just prior to landfall

[Kingarabian]

Now... this does NOT mean it cannot weaken before landfall a little.

However, this close to the coast, and the fact recon is heading in, one should wait for the data before adjusting the winds. What happens if recon finds 70-75 kt winds. Only makes CPHC look foolish

This is why I'd rather the specialists at NHC handle this, not a WFO office that does not routinely handle TCs

Is there another recon mission underway? I thought the previous one was possibly the last one.

I THINK the next one will reach the storm just prior to landfall

Well they need to go full thrust if that's the case.