Maui Weather Forecast for April 22, 2021
West Side
Today: Mostly sunny, with a high near 85. Breezy, with a light and variable wind becoming east northeast 10 to 15 mph in the afternoon. Winds could gust as high as 21 mph.
Tonight: Mostly clear, with a low around 67. Breezy, with an east northeast wind 5 to 15 mph, with gusts as high as 21 mph.
Friday: Mostly sunny, with a high near 84. Breezy, with an east northeast wind 5 to 10 mph increasing to 17 to 22 mph. Winds could gust as high as 31 mph.
South Side
Today: Isolated showers after noon. Partly sunny, with a high near 85. Light and variable wind becoming west 5 to 8 mph in the afternoon. Chance of precipitation is 20%.
Tonight: Partly cloudy, with a low around 66. West wind around 6 mph becoming calm in the evening.
Friday: Isolated showers after noon. Partly sunny, with a high near 86. Light and variable wind becoming northeast 6 to 11 mph in the morning. Chance of precipitation is 20%.
North Shore
Today: Isolated showers before noon. Mostly sunny, with a high near 84. Windy, with an east northeast wind 9 to 14 mph increasing to 19 to 24 mph in the afternoon. Winds could gust as high as 31 mph. Chance of precipitation is 20%.
Tonight: Isolated showers. Partly cloudy, with a low around 66. Breezy, with an east wind 15 to 22 mph, with gusts as high as 29 mph. Chance of precipitation is 20%.
Friday: Isolated showers before noon. Mostly sunny, with a high near 84. Windy, with an east northeast wind 15 to 25 mph, with gusts as high as 36 mph. Chance of precipitation is 20%.
Central Maui
Today: Mostly sunny, with a high near 84. Windy, with a north wind 6 to 11 mph becoming north northeast 18 to 23 mph in the morning. Winds could gust as high as 28 mph.
Tonight: Mostly clear, with a low around 65. Breezy, with a northeast wind 7 to 17 mph, with gusts as high as 23 mph.
Friday: Mostly sunny, with a high near 84. Windy, with a northeast wind 8 to 13 mph increasing to 18 to 23 mph in the afternoon. Winds could gust as high as 32 mph.
Upcountry
Today: Mostly sunny, with a high near 71. Calm wind becoming west around 6 mph.
Tonight: Mostly clear, with a low around 56. Light south wind.
Friday: Mostly sunny, with a high near 71. Breezy, with a light and variable wind becoming east 10 to 15 mph in the morning. Winds could gust as high as 21 mph.
East Maui
Today: Scattered showers. Mostly cloudy, with a high near 82. Light and variable wind becoming east 6 to 11 mph in the morning. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.
Tonight: Showers likely, mainly after 1am. Mostly cloudy, with a low around 63. East wind around 5 mph becoming calm in the evening. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.
Friday: Showers likely, mainly before 1pm. Mostly cloudy, with a high near 81. South wind 5 to 13 mph becoming east in the morning. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.
Lanai City
Today: Scattered showers after noon. Partly sunny, with a high near 75. Breezy, with a northeast wind 5 to 10 mph becoming northeast 11 to 16 mph in the afternoon. Winds could gust as high as 22 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.
Tonight: Partly cloudy, with a low around 62. East northeast wind 5 to 11 mph.
Friday: Isolated showers after noon. Partly sunny, with a high near 76. Breezy, with an east northeast wind 6 to 11 mph increasing to 15 to 20 mph in the afternoon. Winds could gust as high as 28 mph. Chance of precipitation is 20%.
Kaunakakai
Today: Mostly sunny, with a high near 83. North wind 5 to 11 mph becoming east in the morning.
Tonight: Mostly clear, with a low around 70. East northeast wind 6 to 11 mph.
Friday: Mostly sunny, with a high near 83. Breezy, with an east northeast wind 6 to 16 mph, with gusts as high as 22 mph.
Detailed Forecast
Synopsis
Moderate to breezy easterly trade winds will return today and persist through the weekend, with clouds and showers favoring windward and mountain locations. Windward shower coverage could increase late Friday through Saturday night as an upper disturbance moves through from north to south. Warm and humid conditions may return early next week as the trade winds diminish in response to a cold front passing far to the north.
Discussion
The surface trough analyzed near Kauai that disrupted the trade winds through the first half of the week will begin to retreat westward and away from the area through Friday. A pattern transition will result locally with easterly trade winds returning from east to west as high pressure builds to the north. This combined with rising upper heights and plenty of mid-level dry air will translate to more of a stable trade wind regime through tonight. Showers will favor the typical windward and mountain locations – with the best coverage likely through the overnight and early morning periods.
Windward shower coverage may increase late Friday through Saturday night as an upper low drops southward into the area. Some showers could spill over into leeward locations as the inversion lifts/weakens and the trades become breezy. In addition to the increasing shower coverage, a thunderstorm or two can’t be ruled out over the Big Island slopes through the afternoon hours Friday and Saturday.
Guidance remains in decent agreement early next week and shows the previously discussed upper low briefly drifting south of the state Sunday through Sunday night, then lifting back through the area and phasing with a shortwave trough passing far to the north Monday through Tuesday. Subtropical ridge will weaken once again as the attendant cold front passes to the north. If this scenario evolves, a land and sea breeze regime with warm and humid conditions will return and continue through the first half of next week. Clouds and showers will shift back over interior and leeward locations through the afternoon hours.
Aviation
Light trade winds appear to be returning near Maui and the Big Island early this morning. The background flow remains light and variable in the vicinity of the smaller islands west of Maui. Local land breezes are dominating the low-level flow over most of the individual islands. The land breezes have kept low clouds to a minimum over most areas. However, scattered to broken low clouds and isolated showers are moving into the windward side of the Big Island. This may cause brief MVFR conditions along the Big Island windward slopes this morning. Otherwise, VFR conditions are expected to prevail over most areas this morning.
Light to moderate trade winds are forecast to return across the entire state later today. The low-level trade wind flow may bring some low clouds and brief showers to the windward sections on some of the islands later today and tonight.
No AIRMETS are currently in effect, and none are anticipated through this afternoon.
Marine
A surface high passing north of the islands today through Friday then stalling north-northeast over the weekend will result in a boost in the trade winds with speeds reaching locally strong for waters around Maui County and south of the Big Island between today and Sunday. The trades are then expected to trend down while becoming southeast Monday, then hold through Wednesday as the high weakens.
The arrival of the northwest has resulted in a small to moderate bump along the north and west facing shores. This swell is slated to peak today followed by slow decline through Friday. Expect a small to moderate, long- period west- northwest swell to arrive next Monday night and peak Tuesday, followed by a slow decline. A small short period west- northwest to northwest pulse is expected reach our north and west facing shores next week Wednesday night.
A continuous stream of small, but long-period swell from the south and southwest will maintain small surf along south facing shores through next week Wednesday. Surf along the east facing shores will be on the rise Friday and Saturday when the trades turn breezy. Expect surf to build to small to moderate heights, then start diminishing Monday as the trade winds weaken.
HFO Watches/Warnings/Advisories
Small Craft Advisory until 6 AM HST Saturday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.
Data Courtesy of NOAA.gov