Hurricane Nolo continues to slowly move to the north towards the Big Island, and is expected to make a turn to the west tonight. Moisture on the north side of Nolo will interact with the terrain of the Big Island and Maui, and could lead to significant flash flooding, particularly on the windward and southeast portions of the Big Island. Localized strong and gust winds are possible statewide, with the highest winds expected on the Big Island due to the proximity to Nolo.
The main change this morning to the forecast was to lower the additional rainfall that could fall over Maui County and the Big Island, and to modify the winds in keeping with the latest forecast track and intensity of Hurricane Nolo.
Hurricane Nola continues to moving slowly northward towards the Big Island early this morning. An upper level trough west of the islands is helping to steer Nolo. As the trough moves to the west tonight and Saturday, Nolo should begin to make its turn westward. Then a building ridge north of the state will help Nolo to continue to move to the west. The current forecast track is similar to yesterday evenings forecast, however with a delay in the onset of rain on the Big Island and Maui, and in keeping with other model guidance, have lowered the additional rainfall that is expected for those areas. While we have lowered some of the threat, the possibility of flooding continues. And with many areas of the southeast portion of the Big Island susceptible due the recent rains, any additional rainfall could cause significant issues. As such, the Flood Watch continues for Maui and the Big Island. Additionally, some modifications to the winds, primarily to lower them over the next couple of days, have been made, also keeping with the latest model guidance.
With regards to the winds over Kauai County and Oahu, have opted to hold off on any wind headlines this morning. The west turn timing plays a big factor in many parts of the forecast, including the timing of winds for Kauai County and Oahu. Oahu remains at a slightly higher chance for meeting High Wind Warning criteria, but still a good shot for Kauai reaching advisory levels.
Satellite derived precipitable water (PW) shows the deeper moisture has moved over the Big Island, but radar shows that the shower activity remains to the south. Still expecting shower activity to increase over the Big Island today as Nolo moves north, pushing that moisture area into the Big Island. The additional rainfall totals were trended down with the morning package, 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.
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 across most of the islands today with gusts peaking between 25 to 35 knots while gusts up to 40 knots are possible at the windiest sites. Winds are expected to remain gusty through the end of the TAF period. Confidence has decreased slightly in showers reaching the more northern islands given Nolo's more southerly track. That being said, trade showers are likely to continue across the northern islands today while heavier rain remains concentrated from Molokai down through the Big Island. The highest potential for moderate to heavy rain remains across the Big Island with reductions in ceilings and visibilities likely as shower activity becomes more frequent. This may result in periods of IFR to LIFR conditions in heavier showers on the Big Island today into tomorrow. Thunderstorm chances remain low for the Big Island. Temporary MVFR conditions are possible across the rest of the islands as showers develop.
AIRMET Sierra is in effect for mountain obscuration for windward areas of Maui, Molokai, and the entire Big Island.
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 3 AM HST, the center of Hurricane Nolo was located approximately 180 nautical miles south of South Point, Big Island. Nolo is expected to strengthen the next couple of days as it tracks slowly north through the day and then turns west this weekend, passing south of the Hawaiian Islands. Nolo's maritime impacts will include tropical storm/gale force winds, large waves, and high rain probabilities across both the nearshore and offshore waters through the weekend. A Tropical Storm Warning and a Hurricane Watch remains in effect 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. A Small Craft Advisory remains in effect for the remainder of the near coastal waters and channels surrounding Kauai and Oahu.
Hurricane Nolo will produce a moderate size, long period south swell that will result in surf exceeding High Surf Advisory thresholds along exposed southern shores, initially for Big Island today and tomorrow, and then possibly expanding westward across the state early next week. Strong trades will likely result in advisory level surf for the eastern island east and southeast- facing shores through tomorrow, potentially expanding to remaining islands this weekend as stronger winds expand westward. A High Surf Advisory will remain in effect for the east and southeast- facing shores of Big Island, Maui and Molokai. For the western islands, a small southwest swell will build in from today and hold into the weekend.
A small, long period northwest swell will fill in this weekend and keep 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 the next several days, with the largest waves (which could reach upwards to 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.
