(BIVN) – Hurricane Lowell has reached the western edge of the main Hawaiian Islands this evening.
As of 5 p.m. Monday, the Central Pacific Hurricane Center reports Lowell remains a strong category 2 hurricane, with maximum sustained winds at 110 mph. Lowell was 170 miles southwest of Lihue, and heading north-northeast at a swift 18 mph.
Tropical-storm-force winds, which extend outward up to 175 miles (280 km) from the center of the storm, have reached Niʻihau and Kauai. Lihue Airport on Kauai recently reported sustained winds of 38 mph (61 km/h) with a gust to 49 mph (79 km/h).
The core of Hurricane Lowell is expected to pass near or just west of Niʻihau tonight and early Tuesday.
A Hurricane Warning is in effect for Kauai County, where dangerous conditions are already developing this afternoon. There are numerous reports of weather impacts of flooding and crashing ocean waves.
A Tropical Storm Warning is also in effect for Oʻahu.
UPDATE – (5:50 p.m.) – Governor Josh Green announced Monday morning that state and County offices in Kauai will be closed on Tuesday, September 8th. Later in the day, he made another announcement, extending the closures to Oʻahu. From the State of Hawaiʻi:
Governor Josh Green today announced that state and county offices, Hawaiʻi State Department of Education public schools, Oʻahu and Kauaʻi campuses of the University of Hawaiʻi and Hawaiʻi State Judiciary facilities on Oʻahu and in Kauaʻi County will be closed Tuesday, September 8, because of the continuing threat and impacts of Hurricane Lowell.
The closures include state offices on Oʻahu and in Kauaʻi County, City and County of Honolulu offices, Kauaʻi County offices, Judiciary facilities on Oʻahu and in Kauaʻi County, as well as public schools and UH campuses on Oʻahu, Kauaʻi and Niʻihau.
Essential government services and emergency operations will continue.
“Hurricane Lowell is bringing dangerous conditions, including the threat of destructive winds, flash flooding and damaging surf,” said Governor Green. “Closing offices and schools will help keep people off the roads, reduce unnecessary travel and allow emergency crews to focus on protecting our communities. Please remain indoors, avoid unnecessary travel and follow all official emergency instructions.”
Public schools in the counties of Hawaiʻi and Maui are expected to open Tuesday, except for individual campuses that cannot safely reopen because of storm-related conditions.
UPDATE – (5:47 p.m.) – “At this time all state and county government operations on Hawaii Island and all schools on Hawaii Island will be open tomorrow,” the Hawai’i County Civil Defense confirmed Monday evening.
For Hawaiʻi island, a Flood Watch remains in effect, as well as a High Surf Warning for south and west-facing shores, and a High Surf Advisory for east-facing shores.
From the Central Pacific Hurricane Center at 5 p.m. HST:
Lowell’s core structure this afternoon continues to gradually decay as it interacts with an upper-level trough and vertical wind shear increases. The eye is no longer observed on satellite imagery, nor in radar data from Kauai (PHKI), or from the Air Force Reserve Hurricane Hunters making center fixes. As Lowell interacts with the upper-level trough, the flight-level winds on the eastern side of the storm have increased, with the earlier recon mission finding 700 mb winds up to 131 kt. However, a dropsonde launched in the area of maximum wind suggested that the flight level wind reduction to the surface was much higher than usual, which makes sense because these winds aloft occurred in an area with few convective echos from the PHKI radar. This information provides justification to hold Lowell’s initial intensity at 95 kt for this advisory. Another Air Force Reserve Hurricane Hunter Mission is in the hurricane right now and will continue to provide updated data this evening into the overnight hours.
The hurricane’s initial motion remains north-northeastward at 025 degrees at 16 kt. Lowell’s interaction with a mid- to upper-level trough has led to the storm accelerating to the north-northeast today as the hurricane is steered between this feature and an extensive deep-layer ridge to the east of the Hawaiian Islands. The hurricane should maintain this motion with a subtle bend back left as it makes its point of closest approach to Kauai tonight. Ultimately the upper-level trough is forecast to weaken and or lift out, with the mid-level ridging building build back to the northwest of Lowell. This synoptic pattern should result in the the cyclone turning sharply to the northwest and then west in the 36-60 h time frame, with the NHC track following the most reliable HFIP Corrected Consensus Approach (HCCA) and Google DeepMind (GDMI) aids. At long range, some of the global models continue to hint at another possible trough interaction in 96-120 h, and the NHC track forecast shows another bend back northwest at that time. However, there remains substantial uncertainty in both the deterministic and ensemble track guidance by the end of the forecast period.
Lowell’s inner-core structure has been gradually decaying due to increasing vertical wind shear, though the ongoing trough interaction is also enhancing the flight level winds on the hurricane’s eastern side as it accelerates. While it is possible some baroclinic processes may help to maintain the hurricane’s wind field tonight, high shear and decreasing sea-surface temperatures (SSTs) should soon result in significant weakening after Lowell passes the Hawaiian Islands. Model guidance continues to show Lowell weakening below hurricane intensity by tomorrow afternoon, and that is reflected in the latest NHC intensity forecast in 24-36 h. Thereafter, more gradual weakening is expected as the shear decreases and Lowell remains over marginally warm SSTs. Like the track forecast, the intensity forecast in 96-120 h remains quite uncertain, as it is unclear how Lowell’s weakened circulation will interact with the next upper-level trough, with solutions ranging from strengthening to dissipation. The long-range intensity forecast remains low confidence, and the official forecast opts to remain close to the guidance mean.
KEY MESSAGES:
1. Kauai County: The core of Lowell is forecast to pass near Niihau tonight and early Tuesday, and damaging hurricane conditions are expected during that time, with the highest winds atop mountains and on windward and leeward slopes. Large damaging waves will impact exposed portions of the coastline, producing dangerous coastal flooding and inundation of low-lying areas through early Tuesday.
2. Periods of heavy rainfall will increase in coverage over the Hawaiian Islands today and continue through Wednesday. This may produce significant flash flooding and mudslides, especially across Kauai County and portions of the Big Island.
3. Oahu: Tropical storm conditions are expected to begin tonight. Strong, damaging wind gusts could cause tree damage and power outages, especially in areas of higher terrain.
4. Large swells will produce life-threatening surf and rip current conditions during the next several days across portions of the Hawaiian Islands.
