CPAC: ISELLE - Post-Tropical

[Yellow Evan]

WTPA33 PHFO 081441
TCPCP3

BULLETIN
TROPICAL STORM ISELLE ADVISORY NUMBER 34
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092014
500 AM HST FRI AUG 08 2014

...RAPIDLY WEAKENING ISELLE OVER THE BIG ISLAND AND MOVING
WEST-NORTHWEST...


SUMMARY OF 500 AM HST...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...19.3N 156.1W
ABOUT 70 MI...115 KM WSW OF HILO HAWAII
ABOUT 180 MI...290 KM SE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

THE HURRICANE WARNING HAS BEEN DISCONTINUED FOR HAWAII COUNTY. A
TROPICAL STORM WARNING IS NOW IN EFFECT FOR HAWAII COUNTY.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

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

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS....IN
THIS CASE IN THE NEXT 12 TO 24 HOURS.

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

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY THE NATIONAL WEATHER SERVICE OFFICE IN
HONOLULU HAWAII.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 AM HST...1500 UTC...THE CENTER OF TROPICAL STORM ISELLE WAS
LOCATED NEAR LATITUDE 19.3 NORTH...LONGITUDE 156.1 WEST. ISELLE IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 13 MPH...20 KM/H...AND THIS
MOTION IS EXPECTED TO CONTINUE THROUGH EARLY SUNDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/H...WITH HIGHER
GUSTS. ADDITIONAL WEAKENING IS FORECAST DURING THE NEXT 48 HOURS...
WITH ISELLE BECOMING A POST-TROPICAL REMNANT LOW BY SATURDAY
AFTERNOON.

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

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB...29.62 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE OCCURRING ON THE BIG
ISLAND AND PARTS OF MAUI COUNTY...AND WILL CONTINUE THROUGH THE
MORNING. TROPICAL STORM CONDITIONS ARE EXPECTED ON OAHU AND KAUAI
COUNTY LATER TODAY.

RAINFALL...RAINFALL TOTALS OF 5 TO 8 INCHES...WITH ISOLATED MAXIMUM
AMOUNTS TO 12 INCHES...ARE EXPECTED ALONG THE TRACK OF ISELLE.
THESE RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AS WELL AS
ROCK AND MUD SLIDES.

SURF...SWELLS GENERATED BY ISELLE ARE PRODUCING VERY LARGE AND
DAMAGING SURF...MAINLY ALONG EAST AND SOUTH FACING SHORES OF THE
BIG ISLAND. THIS DAMAGING SURF WILL DIMINISH LATER TODAY.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...800 AM HST.
NEXT COMPLETE ADVISORY...1100 AM HST.

$$

FORECASTER BIRCHARD

Counting intermediates, isn't this Birchared's like 5th advisory in a row? Poor guy.

[RL3AO]

Well these are probably the busiest days for that office in a long time if not ever. Guy is probably napping in the office.

[Yellow Evan]

Well these are probably the busiest days for that office in a long time if not ever. Guy is probably napping in the office.

True, but there are four hurricane specialists, so you'd think they'd rotate them around one doing one ever six hours. Granted, they likely don't want their employees driving during a tropical storm.

http://www.prh.noaa.gov/hnl/pages/staff.php

[RL3AO]

Oh I can guarantee at least 3 of the 4 are there are all times. Between doing local NWS duties and making the advisory packages, all of them are busy. Maybe this is how they decided to split the duties up.

[galaxy401]

Post analysis of this storm will be very interesting to see.

[Yellow Evan]

WTPA43 PHFO 081501
TCDCP3

TROPICAL STORM ISELLE DISCUSSION NUMBER 34
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092014
500 AM HST FRI AUG 08 2014

BASED ON WSR-88D DATA...ISELLE MADE LANDFALL ALONG THE BIG ISLAND/S
KAU COAST AROUND 230 AM HST...AND IS TRACKING WEST-NORTHWEST OVER
LEEWARD BIG ISLAND AS OF ADVISORY TIME. THE CYCLONE IS WEAKENING
RAPIDLY...AS THE HIGH TERRAIN OF THE BIG ISLAND IS DISRUPTING THE
CIRCULATION WHILE THE SYSTEM IS ALSO ENCOUNTERING 25 TO 30 KT OF
NORTHWESTERLY SHEAR...AS DEPICTED BY THE SHIPS GUIDANCE AND UW-CIMSS
ANALYSES.

INITIAL MOTION ESTIMATE IS 290/11 KT...AS ISELLE LIES ALONG THE
SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE...WITH A WEAKNESS IN
THE RIDGE LOCATED TO THE NORTH. ISELLE IS EXPECTED TO CONTINUE
TRACKING WEST-NORTHWESTWARD AFTER EMERGING FROM THE BIG ISLAND LATER
THIS MORNING. A MID AND UPPER LEVEL TROUGH ALOFT DIGGING SOUTHWARD
ALONG THE FORECAST TRACK WILL ADD TO THE ALREADY STRONG SHEAR...
WITH 20 TO 30 KT OF NORTHWESTERLY SHEAR FORECAST FOR THE NEXT 36
HOURS. THIS SHOULD LEAD TO THE EVENTUAL DECAY OF THE SYSTEM...WITH
REMNANT LOW STATUS FORECAST BY TAU 36...AND DISSIPATION ANTICIPATED
BY DAY 3.

FORECAST POSITIONS AND MAX WINDS

INIT 08/1500Z 19.3N 156.1W 45 KT 50 MPH...INLAND
12H 09/0000Z 19.7N 158.1W 35 KT 40 MPH
24H 09/1200Z 20.3N 160.6W 30 KT 35 MPH
36H 10/0000Z 20.8N 162.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 10/1200Z 21.4N 165.2W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 11/1200Z...DISSIPATED

[tolakram]

Visible loop, only 1 frame visible so far.

http://wwwghcc.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-W%20PACUS&lat=19&lon=-157&info=vis&zoom=1&width=1024&height=768&type=Animation&quality=95&palette=ir1.pal&numframes=5

[galaxy401]

You can see the rotation west of the big island on visible easily.

[CrazyC83]

With that center relocation, could it re-intensify again SW of Hawaii if convection develops on the LLC?

[wxman57]

Yeah, the center (LLC) is well west of the convection. I don't think Iselle qualifies as a TD/TS any longer. Looks like a remnant low. Some stronger winds in higher elevations, but that's about it.

[wxman57]

With that center relocation, could it re-intensify again SW of Hawaii if convection develops on the LLC?

Iselle looks like it's history. No regeneration. Torn apart by shear.

[wxman57]

Here's a visible satellite. I've identified the broad LLC with yellow arrows. Location of the recent recon dropsonde is on the eastern edge of the LLC. Reported 1010mb with mean wind of about 12 kts during the descent.

[tallywx]

With that center relocation, could it re-intensify again SW of Hawaii if convection develops on the LLC?

Iselle looks like it's history. No regeneration. Torn apart by shear.

You mean the shear of two bulky, 14,000' mountains. Don't discount the role that played. It's questionable whether a storm of this diameter, even under perfect conditions, would have made it across.

[galaxy401]

Major tree damage has occurred in Hawaii. A house was torn off its foundation.

[supercane4867]

Persistent heavy rain still coming down on the southern windward side of the Big Island, mudslides should be a major problem there.

[supercane4867]

Major tree damage has occurred in Hawaii. A house was torn off its foundation.

Any photos? That sounds like tornado damage

[galaxy401]

Major tree damage has occurred in Hawaii. A house was torn off its foundation.

Any photos? That sounds like tornado damage

https://www.facebook.com/photo.php?v=10 ... 1820601148

A video. Caused by storm surge apparently.

[Yellow Evan]

I can't see this surviving much longer.

[Senobia]

My daughter lives on the windward side of Oahu in Kaneohe. So far, so good there. She's cooking bacon and eggs for breakfast as I type. As of 9:45am HST, that is - conditions may deteriorate later, but she said all they have so far is a lil bit of wind and some rain.

[wxman57]

Major tree damage has occurred in Hawaii. A house was torn off its foundation.

Any photos? That sounds like tornado damage

Many homes in Hawaii are not built very strong. In fact, the structures may be weaker than mobile homes here. Probably no secure connections between walls and foundation/roof. They just don't get much wind over there. It doesn't take much wind to cause significant structural damage. I bet it would be hard to find an occurrence of 40+ mph sustained wind on the Big Island (lower elevations) in the last few decades.