WPAC: HECTOR - Post-Tropical

[Blown Away]

King, can you post these models runs you are tracking closely?

[Kingarabian]

King, can you post these models runs you are tracking closely?

Here's the 18z GFS being compared to the past 3 runs:

[cycloneye]

We have the major!!

EP, 10, 2018080400, , BEST, 0, 142N, 1303W, 100, 967, HU

[TheAustinMan]

In times like these where slight alterations in the forecast track have large implications in terms of impacts, especially for a meridionally narrow region of interest like the main Hawaiian island chain, it may be more useful to keep tabs on the ensemble spreads rather than looking at the main model runs cycle-to-cycle. These are better at capturing possible changes in how models handle variability in steering and give a more complete picture as to the range of possibilities for tropical cyclone tracks. Keep an eye on the less chaotic run-to-run trends seen in ensemble guidance. From what I've seen, the GEFS at least has recently been modeling a stronger mid-level ridge north of Hawaii in around five days.

[TheAustinMan]

You might be able to pick out a small moat denoting the region between the inner and outer eyewalls as the ongoing eyewall replacement cycle takes place in this afternoon satellite photo from 01:15 UTC. Hector is a rather compact and well-organized system and the stadium-effect eye really accentuates the storm's appearance and intensity. If I had to guess, I'd put the intensity right now at 110 kts (though officially it is currently 90 kt with a tentative best track intensity of 100kt). For those doing their own satellite analyses, I'd suggest sticking with GOES-WEST/15 at this point as it looks like Hector is west enough where GOES-16 data is not particularly useful due to poor viewing angle and limb cooling. The cloud tops are warmer on GOES-WEST but the eye is sampled a lot more clearly.

556 KB. Source: Visible and infrared data originally from GOES MSFC, combined into the traditional RGB scheme using a photo editor

[cycloneye]

Hopefully,GOES-17 West becomes operational soon to have the same great tools that we are seeeing in GOES-16 East.

[cycloneye]

Hurricane Hector Discussion Number 14
NWS National Hurricane Center Miami FL EP102018
800 PM PDT Fri Aug 03 2018

Hector has continued to quickly strengthen since the last advisory,
with the eye becoming more distinct and the cloud tops in the
eyewall cooling to near -80C. Satellite intensity estimates from
TAFB and SAB were 102 kt near 00Z, and given the increasing
organization since that time the initial intensity is increased to
105 kt.

The initial motion is now 275/10. There is again little change to
the track forecast philosophy, as a large subtropical ridge to the
north of the hurricane should steer Hector generally westward
during the forecast period. Due to a weakness in the ridge, the
hurricane is forecast to gain some latitude from 36-96 h. While the
guidance agrees with this scenario, there is a significant amount of
spread between the GFS and NAVGEM on the north side of the guidance
envelope and the UKMET and ECMWF on the south side. The consensus
models are in the center of the envelope, and the new forecast is
close to these in best agreement with the HCCA corrected consensus.
The new forecast is little changed from the previous track.

Recent satellite microwave data show that Hector is developing an
outer eyewall, which suggests the hurricane should undergo an
eyewall replacement cycle during the next day or so. This makes it
a little unclear how long the current intensification will last.
The intensity forecast will show a little more strengthening during
the next 12 hr followed by little change in strength through 36 h.
The HWRF, HMON, and COAMPS-TC models show a little more
intensification at 48-60 h, and the official forecast follows suit.
After that time, while Hector should remain in a light-shear,
warm-water environment, entrainment of drier air should lead to a
gradual weakening of the cyclone. Overall, the new intensity
forecast lies near the upper edge of the intensity guidance.

There is the potential for Hector to bring some impacts to portions
of the Hawaiian Islands by the middle of next week, but it is too
soon to specify the magnitude of the impacts or where they could
occur. This is a good time for everyone in the Hawaiian Islands to
ensure they have their hurricane plan in place. For additional
information on any potential local impacts from Hector in Hawaii,
please refer to products issued by the NWS Weather Forecast Office
in Honolulu at http://www.prh.noaa.gov/hnl.


FORECAST POSITIONS AND MAX WINDS

INIT 04/0300Z 14.2N 130.9W 105 KT 120 MPH
12H 04/1200Z 14.3N 132.4W 110 KT 125 MPH
24H 05/0000Z 14.2N 134.5W 110 KT 125 MPH
36H 05/1200Z 14.2N 136.6W 110 KT 125 MPH
48H 06/0000Z 14.5N 139.1W 115 KT 130 MPH
72H 07/0000Z 15.5N 144.5W 105 KT 120 MPH
96H 08/0000Z 16.5N 150.5W 90 KT 105 MPH
120H 09/0000Z 16.5N 156.0W 80 KT 90 MPH

$$
Forecaster Beven

[xtyphooncyclonex]

My gut tells me there's this scenario of becoming a category 5........ in the West Pacific. What if this follows Oliwa, but peaks stronger in the East/Central Pacific and even more after crossing? Probably, this would be cat 4 at most in the EPac, there's even more potential in the WPac

[1900hurricane]

Eyewall replacement seems to be progressing fairly seamlessly.

[Twisted-core]

If steered by upper levels 2-7 this system will likely be decapitated by the big island mountain.

[CrazyC83]

Interesting they added a message in the discussion, but didn't use the Key Messages format.

[Yellow Evan]

T6.5 near T7.0. I'd say this is getting close to Cat 5 if it wasn't about to ERC.

[Kingarabian]

In times like these where slight alterations in the forecast track have large implications in terms of impacts, especially for a meridionally narrow region of interest like the main Hawaiian island chain, it may be more useful to keep tabs on the ensemble spreads rather than looking at the main model runs cycle-to-cycle. These are better at capturing possible changes in how models handle variability in steering and give a more complete picture as to the range of possibilities for tropical cyclone tracks. Keep an eye on the less chaotic run-to-run trends seen in ensemble guidance. From what I've seen, the GEFS at least has recently been modeling a stronger mid-level ridge north of Hawaii in around five days.

Agreed. Although the stronger ensembles take it further north.

[Kingarabian]

[img]https://i.imgur.com/lIEPBum.gif[/ig]

T6.5 near T7.0. I'd say this is getting close to Cat 5 if it wasn't about to ERC.

Sheesh

[xtyphooncyclonex]

Oh boy, after seeing its structure and success after the ERC this could be much much stronger than forecast.

I'd say it would turn to the northwest, get close to Hawaii, weaken, then strengthen as it enters the West Pac. For some reason, I'm actually just as worried for Japan as I'm worried for Hawaii

[Ntxw]

Stunning system. Easily a Cat 4 already. Very small, circular eye.

[Alyono]

If this undergoes EI, then perhaps the scenario of Maui or Oahu comes back into play

[Yellow Evan]

[img]https://i.imgur.com/lIEPBum.gif[/ig]

T6.5 near T7.0. I'd say this is getting close to Cat 5 if it wasn't about to ERC.

Sheesh

Take back what I said eye was WMG like I thought it was for some reason.

[Alyono]

not strong enough on the gfs initialization. It also has significant weakening tomorrow for unknown reasons

[Ntxw]