textproduct: Honolulu

SYNOPSIS

Hurricane Lowell is lifting northward away from the islands this morning, and the National Hurricane Center has cancelled the Hurricane Warning for Kauai County and the Tropical Storm Warning for Oahu. Southerly winds are quickly declining across the island chain but will remain breezy and locally gusty through the remainder of the morning, especially on Kauai County. A moist southerly flow will maintain the threat of flooding through at least today and possibly through Wednesday in some areas. Trade winds will slowly build over the state late Wednesday and Thursday, but conditions will remain somewhat wet. Drier trade wind weather will develop THursday night and Friday.

DISCUSSION

As 8 AM HST, Hurricane Lowell continued to move northward and was centered about 190 miles north-northwest of Lihue. Winds have declined considerably, and the National Hurricane Center has cancelled the Hurricane Warning for Kauai County and the Tropical Storm Warning for Oahu. Declining southerly winds will still be breezy and locally gusty through the remainder of the morning, especially on Kauai County where gusts of 30 to 40 mph have recently been observed in the past hour. Shower activity has dropped considerably during the past several hours. Kauai received widespread rainfall of 2 to 6 inches overnight, but as Lowell has lifted northward, showers have recently been light and focused on interior terrain. Over the rest of the island chain, less than 2 inches were observed overnight. No organized moisture is anticipated today, and while the flood threat will be declining, localized heavy showers could develop over terrain on any island today.

Lowell will continue to move away from the area tonight and Wednesday, leaving the islands under a humid south to southeast flow. The GFS and ECMWF are showing a broad but weak area of convergence near the Big Island and Maui that could maintain some threat of flooding. Across Oahu and Kauai, expect spotty showers, some heavy.

High pressure is forecast to build back in late Thursday through Saturday, bringing back a weak trade wind pattern. Moisture may still take a bit longer to exit the area, so expect some enhancement to shower activity to persist.

AVIATION

Hurricane Lowell continues to move northward away from the state of Hawaii. Deep and somewhat unstable tropical moisture continues to stream northward across all islands. Shower activity will linger even after Lowell begins to move farther northward away from the Hawaiian Islands today.

Periods of MVFR conditions with low cloud ceilings and showers will linger across the state. MVFR shower activity will gradually decrease through the morning hours. Surface winds will also steadily decrease today.

AIRMET Sierra for low MVFR cloud ceilings remains in effect and will gradually diminish in coverage through the morning hours.

AIRMET Tango remains in effect for moderate low level turbulence affecting the island of Kauai and Oahu over and NW thru NE of island mountains. A strong surface wind AIRMET remains in effect for Kauai for wind speeds greater than 30 knots due to Hurricane Lowell. These AIRMETs will likely be cancelled later this morning.

MARINE

Hurricane Lowell is now lifting north of Kauai and Niihau. As a result, the Hurricane Warning has been canceled for the coastal waters west of Kauai, and the Tropical Storm Warning has been canceled for waters elsewhere near Kauai and Oahu. The Small Craft Advisory (SCA) remains in effect for all coastal waters for a combination of winds and seas. Winds and seas are expected to decrease rapidly today as the hurricane weakens and moves away from the islands, falling below SCA criteria by this evening. For the western offshore waters, hurricane conditions are expected to continue today until the cyclone exits the region to the northwest.

Southwest swell from Hurricane Lowell is continuing to produce damaging surf to portions of Kauai County with the potential for damage to coastal properties and infrastructure, particularly to those areas along the coast exposed to the southerly swell over the next several hours. Surf will quickly fall to advisory criteria by mid- late morning and then below advisory criteria by tonight. An additional moderate, long-period south swell which is peaking today will then keep surf elevated just below advisory criteria once the southwest swell from Lowell fades by this afternoon. This southerly swell will maintain some south shore surf as it gradually fades through Thursday.

A medium-period east swell from former Tropical Storm Karina combined with east to southeast wind wave generated by Hurricane Lowell will maintain advisory level surf along east facing shores this morning, but will drop below advisory levels by tonight. Surf along north facing shores is also experiencing a solid rise due to Lowell, which is now located northwest of the island chain. This swell will quickly fade through the week as Lowell weakens and tracks away from the islands.

FIRE WEATHER

Fire weather risk will remain low the next several days due residual moisture associated with Hurricane Lowell. Expect a slight chance of thunderstorms over the Big Island on Wednesday afternoon and Thursday afternoon. Temperature inversion heights are expected to remain elevated or weak.

HFO WATCHES/WARNINGS/ADVISORIES

Flood Watch until 6 PM HST this evening for all Hawaii islands-

High Surf Warning until 6 PM HST this evening for Niihau-Kauai Leeward-Waianae Coast-Kahoolawe-Maui Leeward West-Kona-Kohala- Kauai South-East Honolulu-Honolulu Metro-Ewa Plain-Molokai Southeast-Molokai West-Molokai Leeward South-Lanai Leeward-Lanai South-Maui Central Valley South-Kipahulu-South Maui/Upcountry- South Haleakala-Big Island South-Big Island Southeast.

High Surf Advisory until 6 PM HST this evening for Olomana-Kauai East-Koolau Windward-Molokai Windward-Windward Haleakala-Big Island East-Big Island North.

Small Craft Advisory until 6 PM HST this evening for all Hawaiian waters.