Kauai Weather Forecast for December 21, 2022
Today: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 79 to 84 near the shore to around 70 above 3000 feet. Northwest winds around 10 mph in the morning becoming light. Chance of rain 40 percent.
Tonight: Partly cloudy with isolated showers. Lows 63 to 69 near the shore to around 55 above 3000 feet. Light winds. Chance of rain 20 percent.
Thursday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 80 to 85 near the shore to around 70 above 3000 feet. Southwest winds around 10 mph. Chance of rain 40 percent.
Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 69 to 80. Light winds. Chance of rain 30 percent.
Tonight: Partly cloudy with isolated showers. Lows 57 to 68. Light winds. Chance of rain 20 percent.
Thursday: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 69 to 81. Light winds becoming southwest up to 10 mph in the afternoon. Chance of rain 40 percent.
Westerly winds will continue to decrease today as our airmass dries and stabilizes. Expect light winds and limited showers into the weekend. A weak front approaching from the northwest may increase showers near Kauai Friday and Saturday.
The pressure gradient across the islands slackened overnight after the passage of a robust cold front and its supporting upper trough Monday through early Tuesday, resulting in light winds this morning along with a drying and stabilizing trend. The High Wind Warning for the Big Island Summits will be downgraded to a Wind Advisory as post-frontal westerly winds are decreasing there as well. Radar shows very little shower activity across the islands, with the bulk of remaining activity contained in a ragged area associated with a weak trough over and around Kauai.
Expect dry and stable conditions statewide today. Limited moisture will keep cloud cover and rainfall to a minimum this morning. Models show moisture associated with the weak trough near Kauai increasing showers slightly there through today. Lighter winds will allow development of diurnal land and sea breeze circulations, especially over the central smaller islands eastward to the Big Island, through Friday. Southwest winds near Kauai may be just strong enough to limit land and sea breeze flow there. The chance for showers increases near Kauai again on Friday as a weak front approaches from the northwest. However, overall, expect very limited shower activity across the entire state through the end of the week as dry and stable conditions remain anchored over the region.
Models show winds will increase slightly Saturday. However, with a weak front lingering just north of the area, the surface pressure gradient will remain rather slack into early next week. Forecast light winds will allow for another period of land and sea breeze circulations into the beginning of next week. A ridge forecast to slowly strengthen north of the islands by the middle of next week could return a trade wind weather pattern to the state.
Early morning satellite and radar imagery depict mostly dry conditions and relatively few clouds across the state. Fairly dry and stable conditions are expected today, with the exception of Kauai and possibly Oahu later this morning as a weak trough supports slightly more clouds and showers. Some of these showers could produce brief MVFR ceilings, but VFR conditions are expected to prevail at most locations throughout the next 24 hours. Surface winds will remain light throughout the next 24 hours.
There are currently no AIRMETs in effect and none are anticipated through tonight.
A low pressure system far north of the islands will drift northward away from the region over the next 24 hours. Westerly winds will diminish this morning. A weak high pressure ridge will settle in over the Hawaii region over the next few days with two cold fronts passing by north of the state. This pressure pattern will produce light to fresh breezes with shifting wind directions each day into early next week. A Small Craft Advisory remains in effect until this evening for all Hawaiian waters except for Maalaea Bay, due to the high seas from the declining northwest swell.
The current northwest (310-320 degree) swell will quickly decline today through Thursday. A High Surf Warning (HSW) remains in effect this morning for most north and west facing shores, however we may transition to a High Surf Advisory for these areas by this afternoon as swell heights may fall below warning thresholds later today. This swell will continue to trend down statewide into Thursday, just as another northwest (310-320 direction) swell fills into the region. Surf heights with this next swell will approach HSW levels as open ocean swell heights peak near 12 feet from Friday to Saturday. Yet another medium period northwest (310-320 degree) swell will closely follow by Saturday night keeping surf heights elevated along north and west facing shores into early next week.
Small surf heights are expected along east and south facing shores through the week.
High Surf Warning until 6 PM HST this evening for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Olomana, Maui Windward West, Kona, Kohala, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala.
Wind Advisory until 6 PM HST this evening for Big Island Summits.
Small Craft Advisory until 6 PM HST this evening for all Hawaiian waters except Maalaea Bay,
Data Courtesy of NOAA.gov