Trade winds will continue through much of the week with high pressure system far to the northeast. A potential area for tropical development remains about 1100 miles east-southeast of the islands. Conditions remain favorable for tropical development and we will continue to closely monitor how this could impact the islands.
No changes to the forecast with the afternoon package.
High pressure remains far to the northeast of the state and will continue to bring trades to the region this week. Dewpoints remain in the low to mid 70s across the state, so despite the breezy trade winds, it feels muggier than normal. A brief drop in dewpoint temperatures is expected Wednesday, with a return to low 70s on Thursday and Friday. Expect clouds and showers to be focused over the typical windward and mauka slopes in the trade wind flow. Additional clouds and shower are also expected over the Kona slopes of the Big Island during the afternoon and evening hours.
The main concern is related to the area of potential tropical development about 1100 miles east-southeast of the islands. The National Hurricane Center continues to report that the area is conducive for additional tropical development over the next several days. As no system has yet developed, there remain a lot of questions as to where any such system will form and move. As such, the forecast for Hawaii could change significantly once any such system develops. Stay tuned for the latest updates on this developing tropical cyclone from the National Hurricane Center online at www.hurricanes.gov. When and should a system form, the forecast will be updated to reflect the impacts on Hawaii.
Moderate to breezy trade winds are expected over the next several days. Showers will focus mostly over windward and mountain areas, with some lower ceilings over windward and mountain areas this afternoon and tonight. Some heavy showers that developed over upslope Big Island should decrease tonight. Conditions should improve early tomorrow morning as slightly drier air moves in.
AIRMET Sierra is in effect for mtn obsc for windward areas of Kauai and Big Island as well as leeward and upslope Big Island due to persistent showers and low clouds. This AIRMET could continue some of the night as moisture lingers but will likely be cancelled for leeward Big Island as land breezes take hold.
High pressure to the far northeast will remain nearly stationary through midweek as moderate to locally strong trade winds persist through Wednesday. The Small Craft Advisory (SCA) has been extended through Tuesday afternoon for the windier waters and channels around Maui County and the Big Island. The SCA may need to be extended through Wednesday. Later in the week, the focus will shift to the deep tropics southeast of the state. Latest guidance from the National Hurricane Center has a medium chance in 2 days for a tropical cyclone to form southeast of the islands. Depending on the track, it will have differing effects on local winds, seas and weather as early as Thursday. Northeasterly winds appear likely to strengthen as the cyclone approaches during the latter half of the week, but impacts will be highly track- dependent and there is significant forecast uncertainty at this time.
Surf along south facing shores will continue to remain elevated as overlapping south swells continue to impact the islands. A slightly bigger swell will build in Tuesday as another moderate, long period south swell is expected to arrive late Tuesday, fill in Wednesday, and remain elevated through Friday. Surf may approach advisory levels at the peak of the swell.
Surf along east facing shores will continue to remain moderate and rough due to moderate to locally strong trade winds. Later in the week, the track of a developing tropical cyclone will dictate the potential for a swell from the southeast to east. Aside from wrapping trade wind energy, surf along north-facing shores will remain flat to tiny through the week.
Due to a combination of peak monthly high tides and water levels running higher than predicted in a few locations, a Coastal Flood Statement is in effect for minor coastal flooding around the afternoon high tide through at least Tuesday. Tides will be decreasing on Wednesday, but coastal flooding may continue to be possible around high tide for locations where water levels are running highest.
Small Craft Advisory until 6 PM HST Tuesday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.
