Key Message:
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 on 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.
Clouds and showers continue across waters adjacent to Kauai and patchy broken low clouds continue to roll into windward Big Island areas within trade flow, but most land areas are clearer and drier than they were 24 hours ago. Ridging will build from the east as the trough moves away, allowing breezy trade winds to return across the state. Through Saturday, expect typical breezy trade wind weather, with showers likely during the night and early mornings across windward and mauka areas. Leeward areas should see a few isolated showers as well from time to time. Trade winds should steadily increase Saturday afternoon as Tropical Cyclone Douglas approaches the state from the east.
From Saturday night through Monday, weather conditions will depend on the track and intensity of Tropical Cyclone Douglas. While timing and impacts remain uncertain, expect increasing chances of flash flooding and strong winds across portions of the state as early as Saturday night. A Hydrologic Outlook (ESFHFO) remains in effect due to the potential for flash flooding this weekend. With the potential for a tropical cyclone impacting the state this weekend, any preparations such as assembling disaster supplies should be made now. It is recommended to have 14 days of food, water, and medicine for you and your family.
500 AM HST Thu Jul 23 2020
The intensity of Douglas has leveled off in the overnight hours
with the eyewall convection weakening, but the eye temperatures
becoming a lot warmer, suggesting that the system has become a
little more steady state. The wind speed is kept at 105 kt, which
nearly matches the latest CIMSS satellite consensus (SATCON). The
cyclone has less than a day over warm water left to intensify before
it encounters SSTs less than 26C. Douglas should only slowly
weaken thereafter during the next few days due to the cooler waters
along the predicted track since the vertical shear should remain
low through Saturday. As the cyclone approaches the Hawaiian
Islands on Sunday, while the SSTs increase, so does the shear, and
thus a continued weakening is forecast. Model guidance is
consistent from the last forecast, and no significant changes were
made to the NHC wind speed prediction.
Douglas has been moving a little faster to the west-northwest, or
290/17. A large mid-level ridge over the eastern and central
Pacific should continue to steer the hurricane on this general
course and speed for the next couple of days, with some
deceleration and a westward turn by late in the weekend. While the
guidance remains in very good agreement, the only significant
change to note is that this forecast is a bit faster than the
previous one, but not as fast as the ECMWF or its ensemble mean.
FORECAST POSITIONS AND MAX WINDS
INIT 23/1500Z 13.6N 135.9W 105 KT 120 MPH
12H 24/0000Z 14.5N 138.3W 110 KT 125 MPH
24H 24/1200Z 15.8N 141.5W 105 KT 120 MPH
36H 25/0000Z 17.0N 144.6W 95 KT 110 MPH
48H 25/1200Z 18.1N 147.7W 85 KT 100 MPH
60H 26/0000Z 19.1N 150.6W 75 KT 85 MPH
72H 26/1200Z 19.8N 153.5W 65 KT 75 MPH
96H 27/1200Z 20.7N 159.1W 55 KT 65 MPH
120H 28/1200Z 21.5N 165.5W 45 KT 50 MPH
Key Message: 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 on 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.
