Skip Navigation Links
NOAA NOAA United States Department of Commerce

Hurricane DOUGLAS

Hurricane Douglas Discussion Number  19
NWS Central Pacific Hurricane Center Honolulu HI   EP082020
500 PM HST Fri Jul 24 2020
The eye of Douglas has remained visible in conventional satellite 
imagery through the day today, and even cleared out for a little 
while this afternoon, indicating that Douglas remains a powerful 
hurricane. Subjective satellite current intensity estimates ranged 
from 4.5/90 kt to 5.5/105 kt, while ADT was near 5.5. Although the 
eye is clouding up again this afternoon, and surrounding convection 
is cooling, the initial intensity has been held at 100 kt for this 

The forward motion vector has changed little over the past 24 
hours, and is measured to be 295/17kt, as Douglas continues to be 
steered by a mid-level ridge centered to the distant northeast.  
As Douglas draws closer to the main Hawaiian Islands the next 2 
days, it will round the western periphery of the ridge, allowing 
the cyclone to gain some latitude, with some reduction in 
forward speed. Thereafter, a mid-level ridge is forecast to 
build to the north of Douglas, potentially inducing a turn 
toward the west, with some increase in forward speed. The updated 
track forecast is nearly identical to the previous, lies along the 
southern side of a fairly tightly-clustered guidance envelope, and 
is very close to ECMWF ensemble guidance. On the forecast track, 
Douglas will move dangerously close to the Hawaiian Islands, and a 
Hurricane Watch is posted for all islands except Kauai County, which 
may need to be added on Saturday. 

Douglas will be traversing an area of sub-26C SST for the next 36 
hours or so, which is expected to lead a gradual weakening trend, 
despite vertical wind shear on the lighter side, especially by 
central Pacific standards. SSTs along the forecast track increase 
from 48 hours onward, at the same time that Douglas is expected to 
move into an area of increased vertical wind shear as it rounds the 
southwestern periphery of an upper-level ridge. This is expected to 
lead to a continued weakening trend, although at a fairly slow 
rate. The intensity forecast is very close to the SHIPS guidance, 
and close to the IVCN intensity consensus. 

A Hurricane Hunter aircraft is en route to fly an initial mission 
into Douglas, and this valuable data is expected to be available 
for the next forecast update. Additional flights into Douglas are 
scheduled for tomorrow. In the meantime, a morning ASCAT pass was 
used to fine tune the wind radii analysis. 

Key Messages

1. Douglas continues to approach the main Hawaiian Islands, 
potentially passing dangerously close to, or over, the islands 
Saturday night through Sunday night. The close passage of Douglas 
brings a triple threat of hazards, including but not limited to 
damaging winds, flooding rainfall, and dangerously high surf, 
especially along east facing shores. 

2. It is vital that you do not focus on the exact forecast track or 
intensity of Douglas, and remain prepared for changes to the 
forecast. Due to Douglas' angle of approach to the islands, any 
small changes in the track could lead to significant differences in 
where the worst weather occurs. Even if the center remains 
offshore, severe impacts could still be realized over the islands, 
as they extend well away from the center. 

3. 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 Douglas passes near the 
islands. Winds will also be stronger at the upper floors of 
high rise buildings.
INIT  25/0300Z 17.9N 145.1W  100 KT 115 MPH
 12H  25/1200Z 18.8N 147.5W   90 KT 105 MPH
 24H  26/0000Z 20.0N 150.7W   80 KT  90 MPH
 36H  26/1200Z 20.8N 153.5W   70 KT  80 MPH
 48H  27/0000Z 21.4N 156.4W   65 KT  75 MPH
 60H  27/1200Z 22.0N 159.4W   60 KT  70 MPH
 72H  28/0000Z 22.6N 162.5W   55 KT  65 MPH
 96H  29/0000Z 24.0N 169.5W   50 KT  60 MPH
120H  30/0000Z 25.0N 175.5W   45 KT  50 MPH
Forecaster Birchard