Strong high pressure far north of the state will continue to produce breezy to windy trades into the weekend. Showers will primarily focus along windward and mauka areas. An increase in shower coverage and frequency is anticipated later this week and into the weekend, with higher rain accumulations likely occurring during the overnight hours.
Current radar and satellite imagery shows scattered showers moving into windward and mauka areas on the trade wind flow this morning. Strong high pressure centered far north of the state will continue to drive breezy to windy trades across the region through the weekend. Looking aloft, Hawaii will remain under weak ridging through early next week as it lies between two upper- level lows, one to the east, the other to the west.
The breezy to windy trades will generally focus clouds and showers over windward and mauka areas throughout the period. However, batches of deep tropical moisture will move across the area tonight through Friday night, again Sunday into Monday, and more will follow next week. As these batches of deeper moisture move through with PWATs reaching 1.5 to 2 inches, the inversion will weaken and lift, increasing shower coverage and frequency across the state. In addition to the potential for an uptick in shower activity, dew points will be on the rise, leading to muggier conditions through the weekend.
Breezy to locally trades will continue today and once again bring low clouds and scattered showers predominately to windward and mountain areas. There will also be isolated spillover into leeward sites. VFR will prevail for most sites, with occasional localized MVFR mainly for windward/mountain sites associated with the shower activity.
AIRMET Tango remains in effect for moderate low level turbulence over and downwind of terrain for all islands. This AIRMET will likely continue through the next several days.
AIRMET Sierra remains in effect for tempo mountain obscuration above 2500 ft for north through east sections of the Big Island. Sierra may be dropped by later this morning as clouds and showers become less widespread.
Strong high pressure remains centered north of the state, which is driving fresh to strong trade winds across all coastal waters. No ASCAT pass available overnight, but hi-resolution guidance keeps Small Craft Advisory (SCA) winds in many of the coastal water zones though tonight, so will be extending the current SCA through then. Very little chance is expected to the strength of the high or the pressure gradient across the islands, so will continue to remain around the advisory threshold for most waters over the coming days. Windy zones around Big Island and Maui County will likely be extended beyond tonight at a minimum for the SCA, with the possibility of more zones.
A moderate, medium period south southwest (190-200 degrees) swell continues to generate moderate surf below advisory criteria along south facing shores. This swell energy will gradually lower through the remainder of the week. Expect small surf for south facing shores leading into this weekend, with mainly background energy. Another moderate, long-period south southwest swell (210 degrees) is expected to fill in Saturday night, but due to the direction of the source, could be more inconsistent than the current swell.
Surf along east facing shores will remain rough and choppy through the week as fresh to strong trades hold. A small, moderate period west (280 degrees) swell is expected to arrive this weekend and linger into early next week. No significant swells are expected out of the north or northwest.
Looking ahead, higher than normal high tides will be possible beginning during the second half of this weekend. Interests immediately along the coasts in low-lying or vulnerable areas should continue to monitor forecasts for possible coastal flooding due to the King Tides from Sunday through the first half of next week.
Small Craft Advisory until 6 AM HST Thursday for all Hawaiian waters-
