Major Hurricane Douglas

[HillsdaleMIWeather]

Really surprised there's no thread for this.

[Derecho!]

Only way to get a really strong hit is hook from south due to SST profiles, though

[NorthHillsWx]

Douglas has gone beast mode this morning. We’ve seen this story plenty of times before though with storms approaching from the East, they usually are well on their way to becoming devoid of convection by the time they reach the islands, no matter how strong they get before. I can’t argue against history and cold water, this will be a minimal TS by the time of its nearest approach to the islands 

[NJwx85]

4 minutes ago, NorthHillsWx said:

Douglas has gone beast mode this morning. We’ve seen this story plenty of times before though with storms approaching from the East, they usually are well on their way to becoming devoid of convection by the time they reach the islands, no matter how strong they get before. I can’t argue against history and cold water, this will be a minimal TS by the time of its nearest approach to the islands 

Right over the warmest waters currently. As soon at it crosses 15N the water cools dramatically. The best shot of a major landfall in the islands is from the South.

[jbenedet]

SST’s very marginal true, but I do believe the exact track wrt to the NHC’s latest forecast cone will have an outsized impact on intensity, especially given how fast he will be moving...The southern track would result in gradual weakening, likely still a hurricane, whereas the northern track could see this weaken to a cirrus swirl...before closest approach to the islands...

[ineedsnow]

This looks like a 4 almost 5 right now

[NorthHillsWx]

40 minutes ago, ineedsnow said:

This looks like a 4 almost 5 right now

Absolutely. She's a beaut, Clark

[Windspeed]

Impressive..

[hawkeye_wx]

The latest Euro has a 984 mb storm hitting the big island first thing Sunday morning.

[NJwx85]

41 minutes ago, hawkeye_wx said:

The latest Euro has a 984 mb storm hitting the big island first thing Sunday morning.

Unlikely that the core would be able to cross the mountainous terrain of the big island in tact like it shows. If it did manage to make it across in tact, once past the big island it would encounter increasing ocean temperatures. 

[HillsdaleMIWeather]

New cone has it missing the Big Island and hitting closer to Honolulu

[mattb65]

1 hour ago, HillsdaleMIWeather said:

New cone has it missing the Big Island and hitting closer to Honolulu

Technically the cone includes hits on any of the islands but the best track shifted north a bit to hit the northernmost tip of the big island and shoot the gap south of Maui and Oahu.

It seems a question of how much latitude the storm gains before turning west. Unless things shift significantly, it's definitely looking like a strong TS hit for most of the islands.

[Windspeed]

SSTs dip to 25°C east of the Big Island. If Douglas takes a more bending track back at the islands with a greater gain in latitude, I have doubts this will reach the islands as a hurricane. At least that is hurricane force at sea level. A strong TS is possible if the circulation winds down slowly. Interestingly, the top of Mauna Kea would be an interesting place to experience Douglas, as much higher winds in the 600 hPa level could produce hurricane force sustained. Mauna Kea is nearly 14k ft./4.2 km high around 614 mb mean.

[Windspeed]

Looks like Douglas will be a Category 4 on the next advisory.

[mattb65]

Pretty darn impressive looking, probably at or near peak intensity.

[Windspeed]

ADT supports the upgrade. It may not hold Cat 4 intensity long however as MW does show a concentric eyewall feature and an ERC is likely underway.

[Windspeed]

You can even pick up on the ERC underway from colorized WV. Note the developing moat. This would be much easier to see during the day with visible satellite. But it's easy enough to see on WV colorized IR.

[Windspeed]

Looks like they've brought down intensity a tick upon island interaction. I think this is more realistic way to go with the intensity forecast. It could very well hold onto enough organization to be a strong TS but I have a hard time with keeping it a hurricane after traversing such cool water and a more stable air mass.

 

000
WTPZ43 KNHC 240243
TCDEP3

Hurricane Douglas Discussion Number  15
NWS National Hurricane Center Miami FL       EP082020
500 PM HST Thu Jul 23 2020

Douglas remains a well organized hurricane in visible and infrared
satellite imagery.  The 15-nmi-wide eye remains very distinct and
the surrounding cloud tops have cooled since the previous advisory. 
Although not evident in conventional satellite imagery, a recent 
AMSR-2 microwave satellite image showed evidence of concentric
eyewalls.  Subjective Dvorak T-numbers from TAFB and SAB are 
6.0 (115 kt) and recent UW/CIMSS ADT estimates have been creeping 
upward, and now also close to T6.0.  Based on these estimates, 
the initial wind speed has been raised to 115 kt, making Douglas a 
category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. 

Douglas has likely reached its peak intensity as it will be moving 
over cooler SSTs during the next day or so. Although the predicted 
track of the hurricane will bring it over warmer waters when 
Douglas approaches the Hawaiian Islands, vertical shear is forecast 
to increase at that time.  This is expected to result in continued 
gradual weakening, however Douglas is forecast to be near 
hurricane strength when it moves close to Hawaii. Despite the 
slight increase in the initial intensity, the updated NHC wind 
speed forecast is unchanged from the previous advisory through 36 
hours, and then follows the intensity consensus guidance 
thereafter.

Douglas continues moving quickly west-northwestward or 295/16 kt.  
The hurricane is forecast to remain on this heading with some 
slight reduction in forward speed during the next day or so as it 
remains to the south of a large mid-level ridge.  After that time, 
Douglas is forecast to turn westward to the south of another strong 
mid-level ridge the is predicted to build well north of the 
Hawaiian Islands later in the weekend.  The new NHC track forecast 
is very similar to the previous advisory and lies just south of the 
various consensus aids out of respect of the ECMWF and its ensemble 
mean which lie along the southern edge of the track envelope. 


Key Messages:

1.  Douglas is expected to move near or over portions of the
Hawaiian Islands this weekend, and there is an increasing chance
that strong winds, dangerous surf, and heavy rainfall could affect
portions of the state beginning Saturday night or Sunday.  
Interests on the Hawaiian Islands should continue to monitor the 
progress of Douglas and the official forecasts as they evolve over 
the next few days. Watches could be issued on Friday.


FORECAST POSITIONS AND MAX WINDS

INIT  24/0300Z 14.9N 138.8W  115 KT 130 MPH
 12H  24/1200Z 15.9N 141.2W  110 KT 125 MPH
 24H  25/0000Z 17.1N 144.3W  100 KT 115 MPH
 36H  25/1200Z 18.2N 147.4W   90 KT 105 MPH
 48H  26/0000Z 19.2N 150.4W   75 KT  85 MPH
 60H  26/1200Z 20.0N 153.2W   65 KT  75 MPH
 72H  27/0000Z 20.5N 156.0W   60 KT  70 MPH
 96H  28/0000Z 21.3N 161.8W   50 KT  60 MPH
120H  29/0000Z 21.8N 168.5W   45 KT  50 MPH

$$
Forecaster Brown

 

[mattb65]

It seems like there's a trend with each model cycle toward the north side of the cone to the point where it seems less likely that the big island will see significant impacts and it's possible the storm will even go north of the other islands as well. If it doesn't get far enough north, it raises the possibility for a higher impact event on Maui and Oahu as shown on the latest run of the HMON and on the 0z Euro.

However the 12z GFS and Euro show the storm skirting just north of most of the islands, and with the core strength of the storm on its North side, this would be good news.

[Windspeed]

About to find out what a powerful hurricane can do with marginal ~25°C SSTs but good divergence aloft. I am going to say nothing too surprising. Douglas should continue a weakening trend from here on out. The upper trop temps aren't really cold enough to maintain high enough lapse rates to support the eyewall of a hurricane, much less a major, over the cooler body of water east of the islands. Douglas will probably have enough heat flux transport to weaken slowly versus rapidly though. Still, doubt it reaches the islands as a Cat 1.

[yoda]

Hurricane watches issued for some of the Hawaiian islands 

BULLETIN
Hurricane Douglas Intermediate Advisory Number 18A
NWS Central Pacific Hurricane Center Honolulu HI   EP082020
200 PM HST Fri Jul 24 2020

...MAJOR HURRICANE DOUGLAS CONTINUES TO TRACK TOWARD THE HAWAIIAN
ISLANDS...


SUMMARY OF 200 PM HST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...17.4N 144.3W
ABOUT 725 MI...1165 KM ESE OF HILO HAWAII
ABOUT 930 MI...1495 KM ESE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 18 MPH...29 KM/H
MINIMUM CENTRAL PRESSURE...967 MB...28.56 INCHES


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

None.

SUMMARY OF WATCHES AND WARNING IN EFFECT...

A Hurricane Watch is in effect for...
* Hawaii County
* Maui County, including Maui, Lanai, Molokai and Kahoolawe

A Hurricane Watch means that hurricane conditions are possible
within the watch area, in this case within 36 to 48 hours.

Interests elsewhere in the Hawaiian Islands should monitor
the progress of this system.

For storm information specific to your area, please monitor
products issued by the National Weather Service office in
Honolulu Hawaii.

[HillsdaleMIWeather]

BULLETIN
Hurricane Douglas Advisory Number  19
NWS Central Pacific Hurricane Center Honolulu HI   EP082020
500 PM HST Fri Jul 24 2020

...MAJOR HURRICANE DOUGLAS STILL MOVING TOWARD HAWAII...
...HURRICANE WATCH ISSUED FOR OAHU...


SUMMARY OF 500 PM HST...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...17.9N 145.1W
ABOUT 665 MI...1070 KM E OF HILO HAWAII
ABOUT 865 MI...1390 KM ESE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 20 MPH...31 KM/H
MINIMUM CENTRAL PRESSURE...967 MB...28.56 INCHES

[NorthHillsWx]

It’s amazing how naturally protected Hawaii is from hurricanes despite being in the middle of the tropical pacific. 

[WinterWolf]

5 hours ago, NorthHillsWx said:

It’s amazing how naturally protected Hawaii is from hurricanes despite being in the middle of the tropical pacific. 

For sure.  

Although Hurricane Innicky did a job on them almost 30 years ago back in ‘92 I believe?.   She was a beast and hit them with a vengeance. 

[nycwinter]

for a storm to threaten hawaii as a strong storm it would have to travel 500 miles south of the big island to avoid cooler water and drier air then  make a quick turn north like inicki... or lane could have been another inicki but the steering flow was not like inicki to shoot it all the way north.. a storm traveling in the current direction would never be anything but a weak hurricane or most likely a tropical storm  before it hits the islands..

[CheeselandSkies]

Walaka 2018 took a "right hook" track similar to Iniki, but was already too far west to hit the islands.

[mattb65]

This hurricane has been pretty resilient in the face of lower SST and now shear with recon overnight finding 80 kt surface winds and 100 kt flight level winds. This is looking to track dangerously close to Oahu and Kauai, I'm hoping the stronger north side of the storm stays offshore but the latest discussion mentions the shear making the satellite presentation appear further north than the low level center of the storm based on recon.

 

 

Forecast discussion:

Also of extreme value is the fact that 
the low-level center is south of the apparent center seen in 
conventional satellite imagery, and closer to the islands than 
might be otherwise expected. Although island-based radars are also 
detecting Douglas' circulation, they are sampling the upper 
portions of the cyclone that are sheared northward due to southerly 
vertical wind shear. 

https://www.nhc.noaa.gov/text/refresh/HFOTCDCP2+shtml/261451.shtml?

Anxiously waiting to see how it wobbles as it gets closer to mby this afternoon. I'm out on an exposed peninsula on East Oahu, I'll try to get some videos if things go sideways locally. Hoping to not lose power.

[Windspeed]

This hurricane has been pretty resilient in the face of lower SST and now shear with recon overnight finding 80 kt surface winds and 100 kt flight level winds. This is looking to track dangerously close to Oahu and Kauai, I'm hoping the stronger north side of the storm stays offshore but the latest discussion mentions the shear making the satellite presentation appear further north than the low level center of the storm based on recon.  

 

Forecast discussion:

 

 

Also of extreme value is the fact that the low-level center is south of the apparent center seen in conventional satellite imagery, and closer to the islands than might be otherwise expected. Although island-based radars are also detecting Douglas' circulation, they are sampling the upper portions of the cyclone that are sheared northward due to southerly vertical wind shear. 

https://www.nhc.noaa.gov/text/refresh/HFOTCDCP2+shtml/261451.shtml?

Anxiously waiting to see how it wobbles as it gets closer to mby this afternoon. I'm out on an exposed peninsula on East Oahu, I'll try to get some videos if things go sideways locally. Hoping to not lose power.

 

 

 

Earlier in the thread, I doubted this would maintain hurricane intensity all the way into landfall, even with just gradual weakening. Douglas has surprised me to still have 80 kt sustained surface winds at its current location. That being said, it does look like the mid-level vortex is starting to tilt with increasing SSW directional flow above 500 hPa. I don't know, it's going to be a close shave to see if the islands get hurricane force gusts at sea level. Surely along volcanic peaks and ridges, but I feel like the biggest threat here could come from intense westerly orographic ascent producing flash flooding and debris flows. Not downplaying strong minimal cane/TS force gusts by any means if that is how it plays out. Definitely in rare event territory for Maui, Lanai, Molokai and Oahu. Hopefully enough significant weakening will lesson impacts by the time the llc reaches for Kauai.

[CheeselandSkies]

Really surprising how little discussion there is on a rare potential hurricane (as opposed to a shredded apart TS like Lane or Olivia) impact on Hawaii.

[Chinook]

I really didn't expect this hurricane to be at a 90mph intensity near Hawaii, but here it is