Maui Weather Forecast for April 15, 2021
West Side
Today: Sunny, with a high near 85. East northeast wind 5 to 9 mph becoming calm.
Tonight: Clear, with a low around 67. North northeast wind 5 to 11 mph.
Friday: Sunny, with a high near 85. North wind 6 to 9 mph.
South Side
Today: Sunny, with a high near 79. Light and variable wind becoming north 8 to 13 mph in the morning.
Tonight: Clear, with a low around 63. North northeast wind around 9 mph.
Friday: Sunny, with a high near 79. North wind 3 to 8 mph.
North Shore
Today: Isolated showers before 1pm. Sunny, with a high near 79. Northeast wind 9 to 11 mph. Chance of precipitation is 20%.
Tonight: Mostly clear, with a low around 65. North northeast wind 7 to 10 mph.
Friday: Isolated showers between 7am and 1pm. Mostly sunny, with a high near 79. North northeast wind 5 to 7 mph. Chance of precipitation is 20%.
Central Maui
Today: Isolated showers before noon. Sunny, with a high near 80. Breezy, with a north northeast wind 7 to 15 mph, with gusts as high as 21 mph. Chance of precipitation is 20%.
Tonight: Clear, with a low around 65. Northeast wind around 9 mph.
Friday: Isolated showers before noon. Sunny, with a high near 80. North northeast wind 5 to 8 mph. Chance of precipitation is 20%.
Upcountry
Today: Mostly sunny, with a high near 69. Light and variable wind becoming north 6 to 11 mph in the morning.
Tonight: Mostly clear, with a low around 51. Northeast wind around 7 mph.
Friday: Sunny, with a high near 68. Northeast wind 5 to 7 mph becoming calm in the morning.
East Maui
Today: Scattered showers, mainly before noon. Mostly sunny, with a high near 75. North northeast wind 5 to 8 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.
Tonight: Scattered showers. Mostly cloudy, with a low around 67. North northeast wind 7 to 9 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.
Friday: Scattered showers. Partly sunny, with a high near 75. North northeast wind around 8 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.
Lanai City
Today: Sunny, with a high near 73. Breezy, with a northeast wind 11 to 16 mph, with gusts as high as 22 mph.
Tonight: Mostly clear, with a low around 61. North northeast wind 9 to 13 mph.
Friday: Sunny, with a high near 73. North northeast wind 5 to 9 mph becoming light north northwest.
Kaunakakai
Today: Sunny, with a high near 83. Northeast wind 7 to 11 mph.
Tonight: Clear, with a low around 68. Northeast wind around 9 mph.
Friday: Sunny, with a high near 83. North northeast wind 7 to 9 mph.
Detailed Forecast
Synopsis
A surface low and trough located east and northeast of the Big Island will maintain moderate to locally strong northeast winds across the area through today. The trades weaken to light to moderate tonight, and continue into the weekend. A dissipating front will bring a boost to windward and mauka showers over the weekend. A more typical east- northeast trade wind flow returns Saturday night at which point temperatures will be not be as cool. Humidity will be on the rise early next week as southeast winds take over.
Discussion
A northeast trade wind flow will maintain cool temperatures, especially at night, through Saturday. This wind flow is brought on by a slow moving surface low and trough located some 1000 miles northeast of Oahu, and a broad surface high centered far northwest of Kauai. The northeast flow weakens from moderate to locally strong today, to light to moderate tonight and Friday.
As this low/trough ejects out to the northeast tonight, a new surface low forms 500 miles further west along 150W on Friday, resulting in our light to moderate northeast winds becoming more northerly. This new low gets kicked out to the northeast on Saturday, and a weak surface high follows in Saturday night resulting in the return of a more typical east- northeast trades. Between Sunday night and Monday, the trade wind gives way to light southeast winds. Under this wind regime, the weather pattern changes from trades to convective of daytime sea breeze and afternoon showers, and nighttime land breeze.
A front is expected to reach Kauai Friday morning, then on to Oahu in the afternoon. The front stalls and dissipate over Maui County Saturday. As the trade winds return to its usual east- northeast component Saturday night, trade showers will return to all islands.
The windward and mountain sections of most islands are experiencing passing mainly light showers. The lee areas of the smaller islands are feeling a few drops from time to time as well. We anticipate the frequency of these showers to ease off toward late morning, becoming isolated by this afternoon. Scattered showers will pick up once again after the sun sets.
Aviation
Moderate trade winds will persist through this morning and allow for scattered showers to affect mainly the windward coasts and slopes. Brief periods of MVFR ceilings and visibility may be associated with this activity. Otherwise, expect partly cloudy skies and VFR conditions for the leeward locations.
No AIRMETS are currently in effect and none are expected today,
Marine
A trough of low pressure east of the Big Island and broad surface high pressure northwest of the state will maintain moderate and fresh northeast trade winds through today. Last night’s ASCAT satellite pass verified locally strong winds through the Alenuihaha Channel and waters south of the Big Island. Thus, have extended the Small Craft Advisory for those windier waters of Maui County and south of the Big Island through 6 PM HST tonight. Trades will begin to ease tonight and into Friday in response to the northeast trough moving further away from the islands and a developing new low north-northeast of the islands. A weakening front will reach the northern offshore waters this afternoon. The front will dissipate upon reaching Maui County Saturday. A new surface high follows in behind this front Saturday night, ushering in a light to moderate east-northeast trade wind flow. This wind flow changes to a more east to southeast direction Sunday night and Monday. Early to mid week winds will become light and variable as surface high pressure ridging orients itself west- to- east just north of the islands.
Surf will remain small along north and west facing shores through Thursday. A series of moderate, short period north swells will fill in beginning Friday and last through the weekend. This will increase surf along north facing shores through the weekend with an expected slow decline early next week. Surf from these north swells will remain well below high surf advisory levels. East facing shore surf will also remain small through Thursday. North swell may wrap around into some eastern exposures and provide a small bump in east facing shoreline weekend surf. As any remaining south southwest swell fades through Thursday, south facing shore surf will stay small into early Friday. Distant long period swell energy from the southern hemisphere arriving in a couple of days will provide a small boost to southern shoreline surf from Friday into the weekend.
HFO Watches/Warnings/Advisories
Small Craft Advisory until 6 PM HST this evening for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.
Data Courtesy of NOAA.gov