Moderate to locally breezy trades will prevail through today, decreasing slightly by tomorrow, before easing to a more light and variable pattern by this weekend. Shower activity will be kept to a minimum as a cooler and drier airmass filters over the Hawaiian Islands. A cold, upper-level trough makes an appearance late in the week and may slightly enhance trade wind showers, but any meaningful rainfall still remains unlikely.
An upper-level trough remains just northeast of the Hawaiian Islands, continuing to slowly shift northeast, while a broad 1032 mb surface high building in its wake from the northwest. These features will be the catalyst to driving moderate to locally breezy trades across statewide through much of today. Guidance suggests today will be the windiest day of the week, though most locations will remain just below Wind Advisory thresholds. However, it cannot be ruled out that some of the more usual wind- prone locations could occasionally edge near the criteria.
Shower activity will also focus low clouds and showers across windward and mauka areas, but rainfall will be sparse. Latest model guidance continues to show precipitable water values two to three standard deviations below average. This is largely due to a drier airmass filtering in over the entire state. Some guidance preserve the slight uptick in thunderstorm potential of up to 15 percent over the southern slopes of the Big Island. However, with moisture levels running exceptionally low, any storms that do form would likely be "dry" thunderstorms, producing lightning with little to no rainfall. Given that the atmosphere may still be too dry, confidence of storm development, too, remains low.
Looking ahead, trades will begin to ease by tomorrow as the aforementioned high pressure will begin to weaken, becoming light and variable by this weekend and persisting that way through the remainder of the forecast period. Right around the same time, a weak upper- level trough is anticipated to pass within the vicinity of the islands. Moisture will remain limited, though, and any meaningful increase in rainfall still appears unlikely at this time. This system will be monitored and refined throughout the next several days as the pattern evolves.
Moderate to locally breezy trades through tonight. Isol low cigs and SHRA along windward and mauka locations. Some isol pockets of MVFR conds possible, but VFR will prevail.
AIRMET Tango is in effect for mod turb blw 080 downwind of terrain.
Fresh to strong NNE trades through tonight, easing during the second half of the week as a trough develops E of the state and high pressure shifts east. Another trough will develop N of the state towards the end of the week which will further weaken trades. The Small Craft Advisory has been extended through tomorrow due to winds.
A moderate short period NNE (020 degree) swell generated by a gale low NE of the state will hold through tonight. While surf hasn't reached High Surf advisory criteria, the MWS for harbor surges remains in effect until 6pm tonight given little change in surf conditions is anticipated.
Surf along east facing shores will remain choppy due to the strong trade winds, with some areas also being exposed to the incoming NNE swell. South shores will continue to see small pulses from the southern hemisphere over the next few days. A storm- force low developing southeast of New Zealand over the next few days could send a moderate south- southwest swell the following week.
Small Craft Advisory until 6 PM HST this evening for all Hawaiian waters-
