CPAC: DARBY - Post-Tropical

[cycloneye]

 https://twitter.com/RyanMaue/status/757009907983982592

[Kingarabian]

I can see what may be a mid-level circulation crossing the Big Island. Radar animation indicates a lower-level circulation near the south coast. Peak winds at Hilo 19 kts. Doesn't look like much of an impact there. Rain is heading right for the drought-stricken area on the SW side of the island. Looks like mostly a rain event - for an area affected by drought. Not a bad thing (except for the landslides in the mountains).

Conditons should still slowly deteriorate as the main convection area is still off shore. I still think this stronger than 35kts. Looks exactly the same since recon left it.

[cycloneye]

 https://twitter.com/GregPostel/status/757027206182862848

[stormwise]

Yeah it don't look any better than a TD.

[Kingarabian]

Looks like the LLC is on shore. The CPHC should declare landfall already.

[Yellow Evan]

Feel its worth keeping on a TS for the time being since it doesn't really look any worse than it did when Recon confirmed 40-45 knot winds prior to landfall.

[Yellow Evan]

Code: Select all

 23/2330 UTC   19.1N    155.0W       T2.0/2.5         DARBY -- Central Pacific 

[Kingarabian]

I'll always be fascinated by the CPHC'S affection for Dvorak. It hurts me inside when they keep giving Dvorak consideration despite having Recon data available.

[Yellow Evan]

CPHC hasn't mentioned Dvorak in a few discussions.

[Yellow Evan]

WTPA23 PHFO 240235
TCMCP3

TROPICAL STORM DARBY FORECAST/ADVISORY NUMBER 50
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP052016
0300 UTC SUN JUL 24 2016

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

A TROPICAL STORM WARNING HAS BEEN ISSUED FOR KAUAI COUNTY...
INCLUDING THE ISLANDS OF KAUAI AND NIIHAU.

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 WITHIN THE WARNING AREA WITHIN 36 HOURS. IN THIS CASE...
TROPICAL STORM CONDITIONS ARE OCCURRING OVER PORTIONS OF THE BIG
ISLAND...AND ARE EXPECTED OVER MAUI COUNTY AND OAHU WITHIN 24
HOURS.

INTERESTS IN THE EASTERN PORTION OF THE PAPAHANAUMOKUAKEA MARINE
NATIONAL MONUMENT SHOULD MONITOR THE PROGRESS OF DARBY.

TROPICAL STORM CENTER LOCATED NEAR 19.3N 155.8W AT 24/0300Z
POSITION ACCURATE WITHIN 20 NM

PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT 9 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1006 MB
MAX SUSTAINED WINDS 35 KT WITH GUSTS TO 45 KT.
34 KT....... 60NE 40SE 10SW 60NW.
12 FT SEAS..150NE 120SE 60SW 150NW.
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 19.3N 155.8W AT 24/0300Z
AT 24/0000Z CENTER WAS LOCATED NEAR 19.3N 155.3W

FORECAST VALID 24/1200Z 20.0N 156.9W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 60NE 40SE 10SW 60NW.

FORECAST VALID 25/0000Z 21.0N 158.4W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 50NE 40SE 0SW 50NW.

FORECAST VALID 25/1200Z 22.2N 159.8W
MAX WIND 30 KT...GUSTS 40 KT.

FORECAST VALID 26/0000Z 23.6N 161.3W
MAX WIND 30 KT...GUSTS 40 KT.

FORECAST VALID 27/0000Z 27.0N 164.7W...POST-TROP/REMNT LOW
MAX WIND 25 KT...GUSTS 35 KT.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 125 NM
ON DAY 4 AND 150 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY

OUTLOOK VALID 28/0000Z 30.8N 167.8W...POST-TROP/REMNT LOW
MAX WIND 20 KT...GUSTS 30 KT.

OUTLOOK VALID 29/0000Z...DISSIPATED

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 19.3N 155.8W

NEXT ADVISORY AT 24/0900Z

$$
FORECASTER BIRCHARD

[Kingarabian]

:uarrow: CPHC hasn't mentioned Dvorak in a few discussions.

They did yesterday, twice. They go with "recon has found ___ winds despite Dvorak coming in at ___ numbers".

Or they go in the lines of "Recon has found 50kt winds. Please note that Dvorak numbers are much lower"

Also they had the track wrong majority of the time. They wouldve had great track verification if they simply considered the Euro. The NHC uses the GFEX (GFS/Euro blend) all the time and it's always the most sound solution to go with.

[Yellow Evan]

Also they had the track wrong majority of the time. They wouldve had great track verification if they simply considered the Euro. The NHC uses the GFEX (GFS/Euro blend) all the time and it's always the most sound solution to go with.

Eric Blake said in a tweet the other day the ECMWF has been struggling in terms of track with Darby, not to mention the likelyhood of the mountains of Hawaii rejecting the center out to the north, so I understand why they had the track moving where they had it.

[stormwise]

earlier scat just for a comparison reference.

[Kingarabian]

Also they had the track wrong majority of the time. They wouldve had great track verification if they simply considered the Euro. The NHC uses the GFEX (GFS/Euro blend) all the time and it's always the most sound solution to go with.

Eric Blake said in a tweet the other day the ECMWF has been struggling in terms of track with Darby, not to mention the likelyhood of the mountains of Hawaii rejecting the center out to the north, so I understand why they had the track moving where they had it.

Maybe Eric Blake was favoring an eastern track? Because sure the Euro did show an eastern track at first but as soon as it got a better handle on the trough, it shifted consistently west for the past 2 days. I don't think that technically means the Euro was struggling in terms of track. The GFS however, it did.

[Kingarabian]

That being said, Darby making landfall coming from the east and early in the season is alarming.

[Kingarabian]

[stormwise]

Yeah true without the dry air it could have been so much worse. Alyono has predicted this epac/cpac season to almost perfection.

[Yellow Evan]

Also they had the track wrong majority of the time. They wouldve had great track verification if they simply considered the Euro. The NHC uses the GFEX (GFS/Euro blend) all the time and it's always the most sound solution to go with.

Eric Blake said in a tweet the other day the ECMWF has been struggling in terms of track with Darby, not to mention the likelyhood of the mountains of Hawaii rejecting the center out to the north, so I understand why they had the track moving where they had it.

Maybe Eric Blake was favoring an eastern track? Because sure the Euro did show an eastern track at first but as soon as it got a better handle on the trough, it shifted consistently west for the past 2 days. I don't think that technically means the Euro was struggling in terms of track. The GFS however, it did.

 https://twitter.com/EricBlake12/status/756831199700586497

[stormwise]

04.58 wind cant be much planes still flying in...out of hilo airport.

[Kingarabian]

WTPA33 PHFO 240557
TCPCP3

BULLETIN
TROPICAL STORM DARBY INTERMEDIATE ADVISORY NUMBER 50A
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP052016
800 PM HST SAT JUL 23 2016

...DARBY EMERGES BACK OVER WATER WEST OF THE BIG ISLAND...


SUMMARY OF 800 PM HST...0600 UTC...INFORMATION
----------------------------------------------
LOCATION...19.4N 156.3W
ABOUT 25 MI...40 KM SW OF KAILUA-KONA HAWAII
ABOUT 165 MI...265 KM SE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 11 MPH...18 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* All islands in the state of Hawaii.

A Tropical Storm Warning means that tropical storm conditions are
imminent or already occurring. In this case, tropical storm
conditions are occurring over portions of the Big Island, and are
expected over Maui County and Oahu later tonight and Sunday.

Interests in the eastern portion of the Papahanaumokuakea Marine
National Monument should monitor the progress of Darby.

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 800 PM HST (0600 UTC), the apparent center of Tropical Storm
Darby has emerged off the west coast of the Big Island, and is
located near latitude 19.4 North, longitude 156.3 West. Darby is
moving toward the west near 11 mph (18 km/h). Darby is forecast to
make a turn toward the northwest later tonight and continue moving
northwestward over the next 48 hours, with little change in forward
speed.

Maximum sustained winds are near 40 mph (65 km/h) with higher gusts.
Slight weakening is forecast during the next 48 hours.

Tropical storm force winds extend outward up to 70 miles (110 km)
from the center. Sustained winds of 43 mph and wind gusts to 61
mph were reported in Kohala Ranch on the Big Island earlier this
afternoon.

The estimated minimum central pressure is 1004 mb (29.65 inches).


HAZARDS AFFECTING LAND
----------------------
WIND: Tropical storm force winds are expected over the Big Island
tonight, over portions of Maui County later tonight and Sunday, over
Oahu Sunday and Sunday night, and over Kauai County Sunday night and
Monday.

SURF: Swells generated by Darby are expected to impact the
Hawaiian Islands over the next day or so, with swells diminishing
thereafter.

RAINFALL: Storm total rainfall of 8 to 12 inches, with possible
isolated maximum amounts of 15 inches. These rains could produce
life-threatening flash floods and landslides.


NEXT ADVISORY
-------------
Next complete advisory at 1100 PM HST.

$$
Forecaster Houston/Jelsema