CPAC: ISELLE - Post-Tropical

[Frank2]

Earlier in the evening TWC mentioned the waves will be one of the main threats with Iselle - looks to be true. P.S. Different thread I know, but Julio has weakened as well this morning......

[somethingfunny]

Iselle is definitely weakening now. It's also slowed down substantially - the center was supposed to have made landfall a few hours ago. I think that the mountain is absolutely the reason why this is happening, we've seen similar effects with Jamaica and Hispaniola in the Atlantic basin.

Hawaiians/locals here can't tell the difference between 70mph and 75mph anyways.

Most people can't! There really isn't much of a difference. I live in inland Texas and you better believe a sustained 60-70 mph wind would absolutely wreck my neighborhood. Trees that didn't evolve in hurricane-prone climates are not built to withstand that sort of wind.

CPHC still yet to have a public advisory on their website from 3z. And the 6z advisory is nearing.

Edit: http://www.prh.noaa.gov/cphc/tcpages/ar ... 080237.php

CPHC site not working.

You can use the Honolulu NWS office's website to bypass the CPHC server if needed, as all of the information you'd need is also easily accessible there.

http://www.prh.noaa.gov/pr/hnl/

I lowered the advisory intensity to 65 knots because the various RECON intensity estimate techniques in the 23Z pass gave 66 kt, 67 kt, and 68 kt, with 90% of a max flight level wind of 72 knots giving 65 knots. This made going with 70 kt in the 00z intensity a stretch, but we round up slightly for the sake of safety and likely undersampling. Since the pressure continues to rise slowly, and the satellite and radar presentations of the system looking increasingly sheared, I could not justify retaining the 70 knot intensity at 03z.

If you are finding that the CPHC webpage is slow, you should try hitting refresh. Many times we find that people are getting old info on the page because their browser is loading from the cache. There have been many times I've been on the phone with people insisting the page is old when I'm looking at the our page from the office and it's current. The goal here is to publish the complete advisory package by :45, but the discussion almost always goes last as we put together our thoughts. The package is not officially "late" until synoptic + 3 hour.

And yes, you better believe I am a pro-met.

Haha, I believe it, and thank you very much for taking time to post here with us. I know you won't admit being overwhelmed right now but I know how busy you guys are and I really appreciate all your work. I'd love to see some behind the scenes stories after all this is over. I also hope Genevieve's intensity is raised in reanalysis but that's a completely different story.

Mauna Kea Weather Station
http://www.cfht.hawaii.edu/cgi-bin/dl_gemini.csh

This might be the same weather station but it's another website I've found for Mauna Kea weather:

http://mkwc.ifa.hawaii.edu/

I am insanely jealous of the meteorologists staffing Mauna Kea tonight. I'm insanely jealous of them every day for being in Hawaii of course, but especially tonight because Mauna Kea's summit is surely having some insane weather. It's 35 degrees up there at the moment! Currently reporting 51mph southeast winds, I'm not sure if that is a sustained wind but I suspect it would be. I don't know why Reed Timmer isn't at the highest elevation he could access.

[Iceman56]

Getting lots of reports of trees and power lines down, including some major transmission lines, with 18000 on the Big Island without power. Saw a tweet about "roofs flying off" in Hawaiian Paradise Park. WSR-88D velocities from PHWA were over 60 knots at about 3000 feet earlier, which means some of the higher elevation towns are probably taking quite a beating tonight!

[Kingarabian]

Getting lots of reports of trees and power lines down, including some major transmission lines, with 18000 on the Big Island without power. Saw a tweet about "roofs flying off" in Hawaiian Paradise Park. WSR-88D velocities from PHWA were over 60 knots at about 3000 feet earlier, which means some of the higher elevation towns are probably taking quite a beating tonight!

I hope damage is minimal.

Unfortunately it hasn't made landfall yet.

[somethingfunny]

Current Conditions
Temp 3.2 C
RH 98 %
Wind ESE 67 mph
Road Closed

Do you know if these are sustained winds or wind gusts being reported, and of any other weather stations at high altitude?

[Iceman56]

Current Conditions
Temp 3.2 C
RH 98 %
Wind ESE 67 mph
Road Closed

Do you know if these are sustained winds or wind gusts being reported, and of any other weather stations at high altitude?

Those are sustained, the gusts have been as high as 91 mph so far there. The CFHT anemometer is very near the summit of Mauna Kea, well over 13000 feet.

[Kingarabian]

Continuous 40-50mph surface winds over the big island according to news outlets.

[somethingfunny]

Why do you think Iselle's center has slowed down so much? I have two ideas - one being that the storm has lost a lot of deep convection and thus lost contact with the upper-level steering flow - and the other being that winds bouncing off of Mauna Loa are providing pushback steering flow at the lower levels - but all I have are guesses.

[Kingarabian]

Current Conditions
Temp 3.2 C
RH 98 %
Wind ESE 67 mph
Road Closed

Do you know if these are sustained winds or wind gusts being reported, and of any other weather stations at high altitude?

Those are sustained, the gusts have been as high as 91 mph so far there. The CFHT anemometer is very near the summit of Mauna Kea, well over 13000 feet.

Did you finish up writing up the discussion yet, can you show us a sneak peak?

[Brent]

The Weather Channel saying Iselle downgraded to a TS but I don't see the official text yet

[Kingarabian]

The Weather Channel saying Iselle downgraded to a TS but I don't see the official text yet

Yeah it's down to 70mph.

[supercane4867]

And its taking forever to make a landfall

[somethingfunny]

WTPA23 PHFO 080840
TCMCP3
TROPICAL STORM ISELLE FORECAST/ADVISORY NUMBER 33
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092014
0900 UTC FRI AUG 08 2014

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* HAWAII COUNTY

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* MAUI COUNTY...INCLUDING THE ISLANDS OF MAUI...MOLOKAI...LANAI...
AND KAHOOLAWE.
* OAHU
* KAUAI COUNTY INCLUDING THE ISLANDS OF KAUAI AND NIIHAU.

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED
SOMEWHERE WITHIN THE WARNING AREA. PREPARATIONS TO PROTECT LIFE AND
PROPERTY SHOULD HAVE ALREADY BEEN COMPLETED.

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

INTERESTS IN THE NORTHWEST HAWAIIAN ISLANDS SHOULD MONITOR THE
PROGRESS OF ISELLE.

TROPICAL STORM CENTER LOCATED NEAR 19.0N 155.1W AT 08/0900Z
POSITION ACCURATE WITHIN 20 NM

PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT 9 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 995 MB
MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT.
50 KT....... 60NE 20SE 0SW 40NW.
34 KT.......150NE 90SE 20SW 120NW.
12 FT SEAS..220NE 150SE 80SW 220NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 19.0N 155.1W AT 08/0900Z
AT 08/0600Z CENTER WAS LOCATED NEAR 18.9N 154.4W

FORECAST VALID 08/1800Z 19.2N 157.1W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 40NE 0SE 0SW 30NW.
34 KT... 90NE 60SE 0SW 70NW.

FORECAST VALID 09/0600Z 19.8N 159.8W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 60NE 30SE 0SW 60NW.

FORECAST VALID 09/1800Z 20.2N 162.0W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 40NE 10SE 0SW 40NW.

FORECAST VALID 10/0600Z 20.8N 164.4W
MAX WIND 30 KT...GUSTS 40 KT.

FORECAST VALID 11/0600Z 22.2N 169.6W
MAX WIND 30 KT...GUSTS 40 KT.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 125 NM
ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY

OUTLOOK VALID 12/0600Z 24.0N 175.5W...POST-TROP/REMNT LOW
MAX WIND 25 KT...GUSTS 35 KT.

OUTLOOK VALID 13/0600Z 25.7N 177.6E...POST-TROP/REMNT LOW
MAX WIND 20 KT...GUSTS 30 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 19.0N 155.1W

NEXT ADVISORY AT 08/1500Z

$$
FORECASTER BIRCHARD

[TheStormExpert]

Looks like all that talk of history being made with this supposedly being the first hurricane making landfall in Hawaii in 22 years backfired.

[supercane4867]

Looks like all that talk of history being made with this supposedly being the first hurricane making landfall in Hawaii in 22 years backfired.

It's still the first tropical cyclone to make landfall in Hawaii in 22 years as long as it makes somekind of landfall

[Equilibrium]

Why do you think Iselle's center has slowed down so much? I have two ideas - one being that the storm has lost a lot of deep convection and thus lost contact with the upper-level steering flow - and the other being that winds bouncing off of Mauna Loa are providing pushback steering flow at the lower levels - but all I have are guesses.

Thinking the same its is backing up on Mauna Loa.


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[TheStormExpert]

Looks like all that talk of history being made with this supposedly being the first hurricane making landfall in Hawaii in 22 years backfired.

It's still the first tropical cyclone to make landfall in Hawaii in 22 years as long as it makes somekind of landfall

That's even more surprising, always thought there were a few other Tropical Cyclone hits in the past two decades.

[somethingfunny]

I'm not entirely convinced that it's ever going to make landfall.

Not that it matters if there's an official landfall or not - Impacts on the ground are what matter, and Mauna Kea is reporting sustained winds of 70mph right now.

[TheStormExpert]

I'm not entirely convinced that it's ever going to make landfall.

Not that it matters if there's an official landfall or not - Impacts on the ground are what matter, and Mauna Kea is reporting sustained winds of 70mph right now.

It would have to go due west to even clip the souther tip of the Big Island.

[Kingarabian]

When the discussion comes out we will find out.