CPAC: LANE - Post-Tropical

[tolakram]

The sat loop still appears to show it somewhat coupled as deep convection is still firing near the center.

https://weather.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-W%20PACUS&lat=19&lon=-158&zoom=1&width=1000&height=800&type=Animation&quality=85&info=ir&palette=ir2.pal&numframes=25&mapcolor=yellow

Possible a better view. In either case, speed it up.

https://weather.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-W%20PACUS&lat=19&lon=-158&zoom=1&width=1000&height=800&type=Animation&quality=85&info=ir&palette=ir5.pal&numframes=25&mapcolor=yellow

[Kazmit]

Definitely doesn't look like a major anymore, but even cat 1 winds will still be damaging if they manage to reach the islands. Rain is also a significant threat. I hope no one lets their guard down because it has weakened, as this was expected anyway.

[BobHarlem]

@MJVentrice

A beautiful display of transverse banding taking place on the western flank of #HurricaneLane; Transverse banding is a common signature of high turbulence. Some background reading material for your pleasure: https://rmets.onlinelibrary.wiley.com/d ... 02/wea.417 …

 https://twitter.com/MJVentrice/status/1032984576770097155




This is interesting since I think there may be more going on than "decoupling"

[tolakram]

Very interesting wobble on the IR.

https://weather.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-W%20PACUS&lat=19&lon=-158&zoom=1&width=1000&height=800&type=Animation&quality=85&info=ir&palette=ir10.pal&numframes=20&mapcolor=yellow

It appears to decouple, you can see a secondary swirl on the E side, then it jumps NE and seems to hold together. On radar the circulation looks almost oval now.

[Hypercane_Kyle]

Looks more like 80 knots max right now. Guess I was wrong with how quickly this thing would weaken.

[BobHarlem]

Recon or visible would help here, but low level still seems to be heading north or just east of north, the transverse bonding may be a signal of some large dynamic change happening with the storm. The Eye is getting pulled north and a bit eastt (really obvious on microwave imagery). But the mid levels I think are whats showing on radar, which makes it hell trying to determine what's up there. Basically I think its getting tugged, but not decoupling.

Weird as it may sound, the big island volcanoes may wind up blocking the low level trades and shear just enough to hold it off (See Flossie from 2007) This is such a unique setup to Hawaii.

[euro6208]

First time i had to watch youtube videos of Hawaii residents packing up and while not shocking because of how rare hurricanes are to them, it is quite surprising to me after the whole day's thoughts...

Maybe Guam can become the 51th state?

Hawaii < Guam...

[rwfromkansas]

Apologies for the ignorant question, but I Googled and found nothing. I saw a comment yesterday about missing recon and another comment about needing recon. Why are they not doing flights?

[tolakram]

Apologies for the ignorant question, but I Googled and found nothing. I saw a comment yesterday about missing recon and another comment about needing recon. Why are they not doing flights?

The only usable airfield is in the potential path of Lane so they had to evacuate.

[NotoSans]

Let's wait and see what visible imagery reveals, but it's likely that the LLCC is now at the edge of the convective overcast. Shear is taking its toll now.

[somethingfunny]

Very interesting wobble on the IR.

https://weather.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-W%20PACUS&lat=19&lon=-158&zoom=1&width=1000&height=800&type=Animation&quality=85&info=ir&palette=ir10.pal&numframes=20&mapcolor=yellow

It appears to decouple, you can see a secondary swirl on the E side, then it jumps NE and seems to hold together. On radar the circulation looks almost oval now.

[i mg]https://i.imgur.com/aDMsodU.gif[/img]

It looks like it's definitely happening now

[tolakram]

First time i had to watch youtube videos of Hawaii residents packing up and while not shocking because of how rare hurricanes are to them, it is quite surprising to me after the whole day's thoughts...

Maybe Guam can become the 51th state?

Hawaii < Guam...

I don't think a comparison of Guam, which is the MOST likely US territory or state to get hit by a typhoon/hurricane, to Hawaii is all that relevant. Generally you don't spend a lot of money for something that is super rare. That's just how it works.

http://www.weriguam.org/reports/item/typhoon-vulnerability-study-for-guam.html

[euro6208]

First time i had to watch youtube videos of Hawaii residents packing up and while not shocking because of how rare hurricanes are to them, it is quite surprising to me after the whole day's thoughts...

Maybe Guam can become the 51th state?

Hawaii < Guam...

I don't think a comparison of Guam, which is the MOST likely US territory or state to get hit by a typhoon/hurricane, to Hawaii is all that relevant. Generally you don't spend a lot of money for something that is super rare. That's just how it works.

http://www.weriguam.org/reports/item/typhoon-vulnerability-study-for-guam.html

Yes i know that. Just trying to make the comparison...

[supercane]

WTPA32 PHFO 241452
TCPCP2

BULLETIN
Hurricane Lane Advisory Number 40
NWS Central Pacific Hurricane Center Honolulu HI EP142018
500 AM HST Fri Aug 24 2018

...DANGEROUS HURRICANE LANE MOVING SLOWLY NORTH TOWARD
THE MAIN HAWAIIAN ISLANDS...
...CATASTROPHIC FLOODING OCCURRING ON THE BIG ISLAND OF
HAWAII...


SUMMARY OF 500 AM HST...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...18.7N 158.0W
ABOUT 180 MI...290 KM S OF HONOLULU HAWAII
ABOUT 145 MI...235 KM WSW OF KAILUA-KONA HAWAII
MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...962 MB...28.41 INCHES

[tolakram]

If it's moving at all it's very very slow. I don't know what to think with just IR and radar to look at. MJVentrice also tweeted that some strange things are going on.

Michael Ventrice
@MJVentrice
18m18 minutes ago

Something is changing in the dynamical structure of #HurricaneLane; Very obvious in the past 6-hour brightness temperature difference plots. Note the big drop in brightness temperature on the west flank, and rise of brightness temperature on the east flank of the hurricane.



@MJVentrice
18m18 minutes ago
I'm not quite sure what this means and what is causing it. I'm sure we'll see some AMS or other meteorology related journal article in the coming years on this evolution.

[tolakram]

WTPA62 PHFO 241410 CCA
TCUCP2

Hurricane Lane Tropical Cyclone Update...CORRECTED
NWS Central Pacific Hurricane Center Honolulu HI EP142018
410 AM HST Fri Aug 24 2018

...DANGEROUS HURRICANE LANE MOVING NORTH TOWARD THE MAIN
HAWAIIAN ISLANDS...
...CATASTROPHIC FLOODING OCCURRING ON THE BIG ISLAND OF
HAWAII...

The eye of Hurricane Lane is being tracked by both the North
Kohala and Molokai WSR-88D radars as the tropical cyclone moves
northward toward the main Hawaiian Islands.

Automated Surface Observations for Peak Gusts:
12:00Z Kohala Ranch, Big Island (KHRH1)....... 68 MPH (109 km/h)
12:00Z Kamuela, Big Island (PHMU)............. 56 MPH (90 km/h)
10:00Z Kawaihae, Big Island (KWWH1)........... 64 MPH (103 km/h)
12:00Z Puu Mali, Big Island................... 54 MPH (87 km/h)
10:00Z Waikoloa, Big Island (WKVH1)........... 52 MPH (84 km/h)
12:00Z PTA West (PKWH1)....................... 60 MPH (97 km/h)
12:00Z Kaneloa, Kohoolawe (KOAH1)............. 52 MPH (84 km/h)
12:00Z Lanai, Lanai (LNIH1)................... 45 MPH (72 km/h)
12:00Z Maalaea Bay, Maui...................... 50 MPH (80 km/h)
10:00Z Makapulapai, Molokai................... 39 MPH (63 km/h)
10:00Z Kuaokala, Oahu......................... 42 MPH (68 km/h)
12:00Z Kawailoa Training, Oahu................ 39 MPH (63 km/h)
09:00Z Oahu Forest NWR, Oahu (OFRH1).......... 74 MPH (119 km/h)
10:00Z Palehua, Oahu.......................... 45 MPH (72 km/h)

Automated Surface Observations for Sustained Wind Speeds:
12:00Z Kohala Ranch, Big Island (KHRH1)....... 38 MPH (61 km/h)
12:00Z Kamuela, Big Island (PHMU)............. 33 MPH (53 km/h)
12:00Z Kawaihae, Big Island (KWWH1)........... 43 MPH (69 km/h)
13:00Z PTA West, Big Island (PKWH1)........... 37 MPH (60 km/h)
09:00Z Oahu Forest NWS, Oahu (OFRH1).......... 46 MPH (74 km/h)

SUMMARY OF 400 AM HST...1400 UTC...INFORMATION
----------------------------------------------
LOCATION...18.6N 158.0W
ABOUT 155 MI...250 KM WSW OF KAILUA-KONA HAWAII
ABOUT 195 MI...315 KM S OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 5 MPH...8 KM/H
MINIMUM CENTRAL PRESSURE...959 MB...28.32 INCHES

$$

Forecaster Bohlin

[Kingarabian]

The ball of convection keeps expanding. Could blanket the islands soon. Dont know what's going on.

[supercane]

WTPA42 PHFO 241518
TCDCP2

Hurricane Lane Discussion Number 40...Corrected
NWS Central Pacific Hurricane Center Honolulu HI EP142018
500 AM HST Fri Aug 24 2018

Hurricane Lane continues to signs of slow weakening due to wind
shear of 20 to 30 knots from the southwest according to the latest
SHIPS and UW-CIMSS analyses. There is no eye evident in satellite
imagery, which is likely a result of these hostile conditions. Radar
reflectivity data from the WSR-88D radars at Molokai and Kohala show
the center is becoming disrupted. The latest satellite intensity
estimates from HFO, JTWC, TAFB and SAB were a unanimous T5.0/90
knots, while the UW-CIMSS ADT was T5.4/100 knots. Based on a blend
of these estimates, the current intensity has been lowered to 95
knots.

Lane began to turn northward Thursday evening, and the current
motion is 360/4 knots. Lane continues to be steered toward the north
along the western side of a mid-level ridge, which is located to the
east of Hawaii. The consensus guidance continues to show a northward
motion, or even a motion toward just east of due north, as the ridge
builds south of Lane. The latest track has shifted to the right of
the previous forecast through the next 36 hours. This more closely
follows the latest consensus track guidance. Note that on this
track, Hurricane Lane continues to approach the central Hawaiian
Islands, so there is no reason to believe that anyone is safe in the
warning area. Assuming Lane begins to weaken, and decouple before,
or after, it hits the islands, the cyclone is forecast to come
increasingly under the influence of the low-level easterlies and
begin tracking westward. Again, the exact time when this will occur
remains highly uncertain, and only a small delay in this decoupling
could bring Lane farther north. This would produce considerably
worse conditions over the islands. Even if Lane remains along the
forecast track, significant impacts are expected in the Hawaiian
Islands.

Our intensity forecast shows some additional weakening, but
continues to trend on the high side of most of the intensity
guidance through 72 hours due to the resilience Lane has shown
during the past few days. Note that the CIRA analysis of Ocean Heat
Content along the latest forecast track continues to show very high
values during the next 24 hours or so. This will likely help
maintain the intensity longer than might be expected with such
strong shear. By early next week, it is possible that Lane will not
survive the shear, and may become a remnant low by day 5.


KEY MESSAGES:

1. It is vital that you do not focus on the exact forecast track or
intensity of Lane, and remain prepared for adjustments to the
forecast. Although the official forecast does not explicitly
indicate Lane's center making landfall over any of the islands, this
remains a very real possibility. Even if the center of Lane remains
offshore, severe impacts could still be realized as they extend well
away from the center.

2. Lane will pass dangerously close to the central Hawaiian Islands
as a hurricane later today or tonight, and is expected to bring
damaging winds. Terrain effects can cause strong localized
acceleration of the wind through gaps and where winds blow
downslope. These acceleration areas will shift with time as Lane
passes near or over the islands. Winds will also be stronger at the
upper floors of high rise buildings.

3. The slow movement of Lane also greatly increases the threat for
prolonged heavy rainfall and extreme rainfall totals. This is
expected to lead to catastrophic, life-threatening flash flooding
and landslides over all Hawaiian Islands.

4. Life-threatening and damaging surf can be expected along exposed
shorelines with localized storm surge exacerbating the impacts of a
prolonged period of damaging surf. The prolonged period of large
surf will also likely produce severe beach erosion.


FORECAST POSITIONS AND MAX WINDS

INIT 24/1500Z 18.7N 158.0W 95 KT 110 MPH
12H 25/0000Z 19.4N 157.9W 90 KT 105 MPH
24H 25/1200Z 20.0N 158.0W 75 KT 85 MPH
36H 26/0000Z 20.4N 159.0W 65 KT 75 MPH
48H 26/1200Z 20.2N 160.9W 60 KT 70 MPH
72H 27/1200Z 20.1N 163.6W 50 KT 60 MPH
96H 28/1200Z 21.5N 166.0W 35 KT 40 MPH
120H 29/1200Z 25.5N 168.5W 30 KT 35 MPH

$$
Forecaster Houston

[Yellow Evan]

Classic CCC pattern emerging.

[txwatcher91]

Classic CCC pattern emerging.

What is a CCC pattern? I'm not familiar with this terminology? Thanks!