Hurricane Nolo will drift northward toward the Big Island through Friday night, before making a turn to the west. As the deep moisture along the northern edge of the system moves northward, rainfall will increase across the Big Island and Maui, leading to the potential for significant flash flooding on windward and southeast Big Island.
No changes to the forecast with the evening package, but considering issuing a wind advisory for Kauai and Oahu with the morning package.
The relatively typical trade wind pattern continues with lower clouds and showers riding in on the easterly winds. Hurricane Nolo continues its slow northward movement towards the Big Island, and plenty of high clouds are reaching Maui County and the Big Island, with some of the high clouds reaching Oahu. Trades continue to gust are currently gusting to around 20-25 mph in most locations with localized gusts approaching 50 mph in some of the more typical windier areas of Maui County and the Big Island.
Satellite derived precipitable water (PW) shows the deeper moisture just south of the Big Island, so expecting that to move overhead in the coming hours. Despite consensus on the position of Nolo, and subsequent placement of deeper moisture, there remains significant differences in the QPF between the global models, particularly over the Kau District of the Big Island. As mentioned in the previous discussion, the rainfall totals were trended down some, however the possibility of localized significant totals remains. Strengthening northeast winds are expected to drive moderate to heavy showers over windward portions of the Big Island and Maui as moisture deepens and spreads northward over the region.
As mentioned above, continuing to evaluate headlines for Kauai and Oahu. Am leaning towards a Wind Advisory, but will see what the latest forecast track for Nolo is by morning to make that decision. A High Wind Watch for Oahu Saturday and Saturday night remains a possibility. The Hurricane Watch and Tropical Storm Warning remain in effect for the Big Island and the Tropical Storm Watch continues for Maui County.
By the middle of next week, troughing will draw Nolo sharply north or northeastward west of Kauai. The end of next week will then feature light south to southeast flow as Nolo lifts north of the area and gradient over the state weakens substantially.
Gusty trade winds continue with scattered showers extending from the Big Island to Oahu this evening. Highest confidence in MVFR conditions on the Big Island with IFR to LIFR conditions becoming more likely late Friday morning into the afternoon as more widespread rain reaches the island. Thunderstorm chances remain low for the Big Island but will increase slightly heading into Friday evening as Nolo moves closer to the islands. Winds strengthen throughout the day on Friday with peak gusts between 30 to 40 knots expected across the islands. Expect winds to stay largely out of the east to southeast. VFR conditions continue for the rest of the islands but brief periods of MVFR conditions are possible if a stronger shower develops.
AIRMET Sierra is in effect for mountain obscuration for windward areas of Maui and the entire Big Island. This AIRMET will likely be expanded Friday to include other areas as Hurricane Nolo continues its approach.
AIRMET Tango remains in effect for moderate turbulence downwind of island terrain due to breezy trade winds. Expect this to continue through the forecast period.
TC SIGMET series Oscar covers Hurricane Nolo.
At 8 PM HST, the center of Hurricane Nolo is located approximately 220 nautical miles south of South Point, Big Island. Nolo is expected to continue strengthening over the next couple of days as it tracks slowly north through Friday, then turns west passing south of the Hawaiian Islands this weekend. Nolo's maritime impacts will include increasing winds, waves, and rainfall probabilities across both the nearshore and offshore waters primarily south of the Hawaiian Islands through the weekend. A Tropical Storm Warning and a Hurricane Watch continues for the nearshore waters surrounding Big Island, including the Alenuihaha Channel, while a Tropical Storm Watch remains in effect for the waters of Maui County including the Kaiwi Channel, and a Small Craft Advisory remains in effect for the remainder of the near coastal waters and channels surrounding Kauai and Oahu.
For the western islands, the current small south swell will continue to fade as another small overlapping southwest swell builds in from Friday into the weekend. Meanwhile, Hurricane Nolo will likely produce a southerly swell resulting in surf reaching advisory thresholds for exposed south-facing shores, initially for Big Island, then potentially expanding westward across the state this weekend. Additionally, strong trades will likely result in advisory level surf for the eastern island east-facing shores tonight into Friday, potentially expanding to remaining islands later Friday into the weekend as stronger winds continue to expand westward. A High Surf Advisory is in effect for the east and southeast-facing shores of Big Island, Maui and Molokai.
A new small, long period, northwest swell will fill in this weekend keeping surf slightly elevated along north and west- facing shores into early next week. Finally, dangerously large wind waves will produce a rough and choppy sea state for much of the area over the next few days, with the largest waves (which could exceed 20 feet in some locations) expected around Maui County and Big Island.
Flood Watch through Saturday afternoon for Big Island East-Big Island Interior-Big Island North-Big Island South-Big Island Southeast-Big Island Summits-Haleakala Summit-Kahoolawe-Kipahulu- Kohala-Kona-Lanai Leeward-Lanai Mauka-Lanai South-Lanai Windward- Maui Central Valley North-Maui Central Valley South-Maui Leeward West-Maui Windward West-Molokai Leeward South-Molokai North- Molokai Southeast-Molokai West-Molokai Windward-South Haleakala- South Maui/Upcountry-Windward Haleakala.
Tropical Storm Watch for Haleakala Summit-Kahoolawe-Kipahulu- Lanai Leeward-Lanai Mauka-Lanai South-Lanai Windward-Maui Central Valley North-Maui Central Valley South-Maui Leeward West- Maui Windward West-Molokai Leeward South-Molokai North-Molokai Southeast-Molokai West-Molokai Windward-South Haleakala-South Maui/Upcountry-Windward Haleakala.
High Surf Advisory until 6 PM HST Saturday for Big Island East- Big Island North-Big Island Southeast-Kipahulu-Maui Windward West-Molokai Southeast-Molokai Windward-South Haleakala-Windward Haleakala.
Hurricane Watch for Big Island East-Big Island Interior-Big Island North-Big Island South-Big Island Southeast-Big Island Summits-Kohala-Kona.
Tropical Storm Warning for Big Island East-Big Island Interior- Big Island North-Big Island South-Big Island Southeast-Big Island Summits-Kohala-Kona.
Tropical Storm Watch for Kaiwi Channel-Maalaea Bay-Maui County Leeward Waters-Maui County Windward Waters-Pailolo Channel.
Hurricane Watch for Alenuihaha Channel-Big Island Leeward Waters- Big Island Southeast Waters-Big Island Windward Waters.
Tropical Storm Warning for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters-Big Island Windward Waters.
Small Craft Advisory until 6 PM HST Saturday for Kauai Channel- Kauai Leeward Waters-Kauai Northwest Waters-Kauai Windward Waters-Oahu Leeward Waters-Oahu Windward Waters.
