March 22, 2018 Weather Forecast

Photo: James Grenz

Our weather team will bring you any urgent weather alerts or updates as they occur. Check our breaking news section for the latest.

**Click directly on the images below to make them larger. Charts include: Hawaii Island high/low forecasted temperatures, projected winds, projected localized weather conditions and expected wave heights.**

Looking Ahead

Cloudy and breezy conditions continue across the state this morning due to strong high pressure to the north and an upper trough positioned several hundred miles west of Kauai near Midway. Water vapor imagery showed plenty of middle- to upper-level moisture being drawn northward east of this upper trough around a mid-level ridge, which supports the cloudy conditions in place. Although most of the shower coverage expected will continue to focus over the typical windward and mountain locations today, heavier showers over Kauai and Niihau are expected as a weak pulse of energy moves through aloft around the mid-level ridge. Latest radar showed a shield of moderate to heavy showers with a few storms embedded moving in from the west over Niihau and Kauai. Expect this trend to continue through the morning hours today.
Guidance remains in decent agreement through the short-term period (through Friday) and appears to be initializing well with the current trends and patterns. Consensus supports breezy trades holding as strong high pressure far north of the area shifts southeastward across the northeast Pacific. The aforementioned upper trough positioned to the west is forecast to begin shifting eastward toward the region today. This upper pattern will continue to support cloudy skies. Highest rainfall chances will remain over the western end of the state where the best source of deeper moisture and upper support exists. Elsewhere, showers will remain focused mostly over windward and mountain areas with a few passing showers leeward periodically.
Conditions will begin to evolve Friday into the upcoming weekend as a shortwave trough digs southeastward into the area bringing a threat for heavy rainfall and even a few storms statewide. Despite the model spread and inconsistencies between various solutions that have been shown in each cycle, most continue to depict low pressure developing along an approaching trough in the vicinity of the islands late Friday into Saturday with an abundance of deep moisture being drawn northward (2″ precipitable water values). A combination of falling upper heights, 0-6 km bulk shear (40-50 kt) profiles, lift, and deep tropical moisture will lead to a wet weekend with a few thunderstorms, especially late Friday through Saturday. The one limiting factor appears to be the instability (high shear/low instability event), which may end up being out of phase with where and when the heaviest activity ends up developing. The best chance for the heaviest rainfall and storms will remain over the western end of the state late Friday into Friday night, then shifting eastward to Maui County and the Big Island Saturday and Saturday night.
Sunday through early next week, improving conditions are expected as drier air fills in and the upper trough and surface low lift northeastward and away from the area. Guidance depicts light west winds, potentially giving way to overnight land breezes and afternoon sea breezes by early next week. Forecast confidence, however, remains low through this extended period provided the spread between solutions shown.

Hilo

Today: Showers likely, mainly before 7am. Mostly cloudy, with a high near 78. Calm wind. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 64. Calm wind becoming west southwest around 5 mph in the evening. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.

Friday: Scattered showers. Mostly cloudy, with a high near 79. West wind around 5 mph becoming light and variable in the morning. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.

Kona

Today: Scattered showers, mainly after noon. Widespread haze. Mostly cloudy, with a high near 79. Calm wind becoming west around 6 mph in the afternoon. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Isolated showers before midnight. Widespread haze. Mostly cloudy, with a low around 66. West northwest wind around 5 mph becoming calm in the evening. Chance of precipitation is 20%.

Friday: Scattered showers after noon. Widespread haze. Mostly cloudy, with a high near 79. Calm wind becoming west 5 to 7 mph in the afternoon. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Waimea

Today: Scattered showers. Mostly cloudy, with a high near 71. Breezy, with a northeast wind 16 to 20 mph, with gusts as high as 26 mph. Chance of precipitation is 40%. New precipitation amounts between a quarter and half of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 54. Breezy, with a northeast wind 10 to 16 mph, with gusts as high as 22 mph. Chance of precipitation is 30%. New precipitation amounts between a tenth and quarter of an inch possible.

Friday: Scattered showers. Mostly cloudy, with a high near 71. Breezy, with a northeast wind 12 to 17 mph becoming light east northeast in the afternoon. Winds could gust as high as 23 mph. Chance of precipitation is 30%. New precipitation amounts between a quarter and half of an inch possible.

Kohala

Today: Scattered showers. Mostly cloudy, with a high near 66. Breezy, with an east wind 14 to 17 mph, with gusts as high as 24 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 46. East wind 7 to 14 mph, with gusts as high as 18 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Friday: Scattered showers. Mostly cloudy, with a high near 66. Breezy, with an east wind 15 to 20 mph becoming southwest 6 to 11 mph. Winds could gust as high as 28 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

South Point

Today: Isolated showers. Widespread haze. Mostly cloudy, with a high near 79. Windy, with an east northeast wind 22 to 24 mph, with gusts as high as 31 mph. Chance of precipitation is 20%.

Tonight: Isolated showers. Widespread haze. Mostly cloudy, with a low around 72. Windy, with an east northeast wind around 23 mph, with gusts as high as 30 mph. Chance of precipitation is 20%.

Friday: Isolated showers. Widespread haze before noon. Mostly cloudy, with a high near 79. Windy, with an east northeast wind 20 to 24 mph, with gusts as high as 31 mph. Chance of precipitation is 20%.

Puna

Today: Scattered showers. Mostly cloudy, with a high near 77. East northeast wind 3 to 8 mph. Chance of precipitation is 50%. New precipitation amounts between a quarter and half of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 62. Northeast wind 5 to 7 mph becoming west northwest after midnight. Chance of precipitation is 50%. New precipitation amounts between a quarter and half of an inch possible.

Friday: Showers likely, mainly after noon. Mostly cloudy, with a high near 78. Calm wind becoming east 5 to 8 mph. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.

Waikoloa

Today: Isolated showers after 1pm. Mostly cloudy, with a high near 79. Breezy, with a northeast wind 10 to 20 mph, with gusts as high as 28 mph. Chance of precipitation is 20%.

Tonight: Isolated showers before 7pm. Mostly cloudy, with a low around 64. Breezy, with an east wind 10 to 16 mph, with gusts as high as 22 mph. Chance of precipitation is 20%.

Friday: Isolated showers after 1pm. Widespread haze after 1pm. Mostly cloudy, with a high near 79. East wind 5 to 11 mph becoming northwest in the afternoon. Chance of precipitation is 20%.

Image: NOAA

Image: NOAA

Image: NOAA

Image: NOAA

Image: NOAA

Image: NOAA

Image: NOAA

Image: NOAA

Data Courtesy of NOAA.gov