Breezy trade winds continue through the weekend with clouds and showers focused windward and mauka. Hurricane Lowell is forecast to move close to Kauai County Monday night as a category 2 to 3 hurricane. Impacts such as high surf and heavy rain are forecast to extend hundreds of miles from the center of Hurricane Lowell, potentially impacting any of the islands.
Breezy trade winds will continue through the weekend. Radar and infrared satellite show partly cloudy skies and scattered trade showers this morning. Clouds and showers will gradually increase through the weekend as trade winds push in a bit more upstream moisture. Focus of the showers will be windward and mauka and occur mostly during the overnight and early morning hours through Sunday.
Our attention will then turn to Hurricane Lowell, now a category 4 on the Saffir-Simpson scale (155 mph maximum sustained winds), and impacts to Hawaii. Lowell is about 625 miles south southwest of Kauai still tracking slowly to the west. Lowell is expected continue westward today and then turn north Sunday. Lowell is expected to make its closest approach to the main Hawaiian Islands Monday night as a category 2 to 3 hurricane, and any deviation eastward from its forecast track could bring more severe wind impacts especially to Kauai County. It is currently too early for tropical watches and warnings this morning, but will be discussed and determined soon. If a watch is issued, we will move to alternative schedule of for this forecast disscussion, zone, state and coastal water forecast to coincide with our production of the Hurricane Local Statement and the National Hurricane Center advisory.
As far as expected impacts, there remains a risk for high surf, strong winds, and heavy rainfall for all islands. A south swell has already elevated surf across south facing shores and will become extra large out of the southwest Sunday night/Monday as Lowell approaches. High surf will have the greatest coverage across the state as the swell moves from the storm, so confidence is highest with the surf and surge impacts.
Winds will shift southward and deep tropical moisture will advect across all islands late Sunday through Tuesday, producing warm and humid weather conditions. Heavy rainfall is likely to impact most islands at some point during Lowell's passage.
High pressure builds back over the islands from Tuesday afternoon onward as a wet trade wind pattern with periods of passing showers sets up across the state into the end of next week. A moist area left from the remains of Karina is now modeled to move through the area Wednesday afternoon through Wednesday night, possibly providing an especially wet period.
Breezy trade winds will gradually decrease in strength through Sunday as the ridge north of the islands weakens. Hurricane Lowell roughly 600 miles south of Kauai continues to journey westward. Bands of unsettled clouds are developing in the trade winds just northeast of the Hawaiian Islands. Expect increasing cloud and shower trends bringing a few passing MVFR conditions over windward mountain areas lasting into the early morning hours with the potential for an AIRMET Sierra issuance for mountain obscurations.
AIRMET Tango remains in effect for low level mod turb over and south through west of all island mountains.
A surface high persists north of the Hawaiian Islands and will slowly drift east through the weekend. Currently, Hurricane Lowell is around 550 nm south-southwest of the islands as it continues to track west. The trade winds are beginning to ease slightly as Lowell gains a bit of distance from the island chain, and the Small Craft Advisory (SCA) has been trimmed back to only the windier waters and channels around Maui County and the Big Island through this afternoon. Lowell is expected to turn northward on Sunday, which will cause winds to veer to the southeast to south with the strongest winds over the western end of the state.
Confidence has grown with the latest updates from the National Hurricane Center for the potential for hurricane conditions in the offshore waters west of 160W Sunday night through Tuesday. While confidence is increasing in the track forecast of the cyclone, a deviation in track of 50 nm west or east from the current predicted path will have significant differences in impact for the coastal waters around Kauai County. As for Hurricane Karina, it is expected to weaken and pass northeast of the state.
Southerly swell generated by Hurricane Lowell will keep surf along south facing shores at High Surf Advisory criteria today. As Lowell begins to turn north on Sunday, its swell will gradually veer from south to southwest and begin a rapid upward trend. Very large surf exceeding warning criteria appears increasingly likely for south and west facing shores on Monday. Coinciding also with monthly high tides, this will create the potential for impacts to harbor entrances, channels, as well as coastal properties and infrastructure including roadways. Surf will then rapidly decrease on Tuesday after the hurricane passes north of the island chain. A pulse of northwesterly swell could then bring a bump to north shore surf on Tuesday and fade through Thursday.
East facing shores will see continued advisory level surf from a large, medium-period east swell generated by Hurricane Karina to the east of the islands. This swell will gradually fade early next week as Karina weakens into a tropical storm. Late next week, surf along east facing shores could be bolstered by some medium-period swell generated by Hurricane Marie in the East Pacific. Otherwise, expect choppy conditions from easterly trade wind swell through the week.
High Surf Advisory until 6 PM HST Sunday for Niihau-Kauai Leeward-Waianae Coast-Olomana-Kahoolawe-Maui Leeward West-Kona- Kauai East-Kauai South-East Honolulu-Honolulu Metro-Ewa Plain- Koolau Windward-Molokai Windward-Molokai Southeast-Molokai West- Molokai Leeward South-Lanai Leeward-Lanai South-Maui Central Valley South-Windward Haleakala-Kipahulu-South Maui/Upcountry- South Haleakala-Big Island South-Big Island Southeast-Big Island East-Big Island North.
Small Craft Advisory until 6 PM HST this evening for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters.
