Maui Weather Forecast for September 28, 2022
West Side
Today: Sunny. Highs 80 to 90. East winds 10 to 15 mph.
Tonight: Mostly clear. Lows 68 to 76. Northeast winds 10 to 15 mph.
Thursday: Sunny. Isolated showers in the afternoon. Highs 80 to 89. Northeast winds 10 to 15 mph. Chance of rain 20 percent.
South Side
Today: Sunny and breezy. Highs around 91. Northeast winds around 10 mph increasing to around 20 mph in the afternoon.
Tonight: Mostly clear. Lows 68 to 76. North winds 10 to 15 mph.
Thursday: Sunny. Highs around 89. North winds 10 to 15 mph.
North Shore
Today: Mostly sunny with a 20 percent chance of showers. Highs 78 to 88 near the shore to around 68 near 5000 feet. East winds 10 to 15 mph.
Tonight: Partly cloudy in the evening then becoming mostly cloudy. A 50 percent chance of showers. Lows around 71 near the shore to 49 to 55 near 5000 feet. East winds 10 to 15 mph.
Thursday: Partly sunny with scattered showers. Highs 78 to 88 near the shore to around 68 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.
Central Maui
Today: Sunny and breezy. Highs 85 to 91. Northeast winds 10 to 20 mph.
Tonight: Mostly clear. Lows 68 to 73. Northeast winds around 10 mph.
Thursday: Sunny. Highs 84 to 90. Northeast winds around 10 mph.
Upcountry
Today: Sunny. Highs around 64 at the visitor center to around 59 at the summit. East winds 10 to 15 mph.
Tonight: Breezy. Partly cloudy with a 40 percent chance of showers. Lows around 51 at the visitor center to around 47 at the summit. East winds 15 to 20 mph.
Thursday: Breezy. Mostly sunny with scattered showers. Highs around 63 at the visitor center to around 57 at the summit. East winds 10 to 20 mph. Chance of rain 50 percent.
East Maui
Today: Mostly sunny with a 20 percent chance of showers. Highs 78 to 88 near the shore to around 68 near 5000 feet. East winds 10 to 15 mph.
Tonight: Partly cloudy in the evening then becoming mostly cloudy. A 50 percent chance of showers. Lows around 71 near the shore to 49 to 55 near 5000 feet. East winds 10 to 15 mph.
Thursday: Partly sunny with scattered showers. Highs 78 to 88 near the shore to around 68 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.
Lanai City
Today: Sunny. Highs 75 to 83. East winds 10 to 15 mph.
Tonight: Mostly clear. Lows around 64. Northeast winds 10 to 15 mph.
Thursday: Sunny. Isolated showers in the afternoon. Highs 74 to 81. Northeast winds around 10 mph. Chance of rain 20 percent.
Kaunakakai
Today: Sunny. Highs 73 to 92. Northeast winds around 15 mph.
Tonight: Mostly clear. A 40 percent chance of showers in the evening. Lows 58 to 75. East winds 10 to 15 mph.
Thursday: Sunny. Isolated showers in the afternoon. Highs 71 to 91. Northeast winds 10 to 15 mph. Chance of rain 20 percent.
Detailed Forecast
Synopsis
Light to moderate trade winds will remain on the dry side of normal for most areas through Thursday, but moisture associated with a dissipating front may bring an increase in windward showers to Kauai beginning tonight. An increase in windward showers is possible for most islands Thursday night and Friday as moisture arrives from the east. Light and variable winds this weekend may bring increased afternoon showers to island interiors, with generally dry conditions at night.
Discussion
A mostly dry and stable trade wind weather pattern remains in place this morning, with latest satellite images showing abnormally few low clouds upstream of the islands from Kauai to Maui, with scattered low clouds approaching the Big Island. Radar shows little in the way of precipitation, and the rain gage network has remained mostly dry over the past 24 hours. A mid- and upper level ridge centered NW of the islands is supporting a strong subsidence inversion based near 6000' over the Big Island, while the Lihue sounding showed a weaker inversion, with PWAT near 1.2″ in Hilo and 1.5″ in Lihue. Little change is expected in the short term, with very little rainfall anticipated today.
Model guidance over the past 48 hours has been advertising an increase in PWAT near Kauai as remnants of a front, now about 150 miles N of Kauai, sags S. This has yet to occur, with nearly clear skies at the moment, but guidance continues to indicate an increase in low-level moisture around Kauai by tonight. If this occurs, there will be some increase in trade wind shower coverage over windward Kauai, while mostly dry conditions persist over the remainder of the state through Thursday.
An uptick in trade wind shower coverage is possible over most islands Thursday night and Friday as moisture associated with a low- level trough presently near 20N 150W moves over the area. Current guidance keeps the bulk of this moisture N of the Big Island. Over the weekend, a slow-moving cut-off low far NE of the islands will send a front southward toward the area, substantially weakening the local pressure gradient. Light E winds will allow land and sea breezes to modulate weather over land. With some moisture lingering and with converging afternoon sea breezes, there could be a healthy coverage of afternoon clouds and showers over interior sections over the weekend. Overnight land breezes should bring clearing each night and morning. Increased moisture associated with the approaching front may move over some of the islands from the N early next week as trade winds restrengthen.
Aviation
High pressure north of the state will maintain moderate trade winds through the forecast period. A relatively dry airmass will limit cloud and shower activity to windward areas. Expect mainly VFR conditions, with brief MVFR possible under passing showers.
No AIRMETs are in effect.
Marine
A weak frontal boundary north of the Hawaiian Islands will diminish today and a high pressure system far to the northeast of the region will produce moderate to fresh trade winds through Thursday. Wind speeds will then weaken from Friday through Monday, as yet another low pressure system sets up north of the region. Wind speeds will likely remain below Small Craft Advisory thresholds through Monday.
A series of small to medium period north and northwest swells from Aleutian sources are expected to increase surf heights along north facing shores through Friday. Medium range guidance shows a cut off low forming far north of the state on Thursday and Friday, sending a north swell towards the islands arriving by Saturday night. A decent fetch area will point towards Hawaii with 20 to 35 knots of wind developing around the west side of the low center. However, the strength of this north swell energy will greatly depend on where and how strong this surface low sets up relative to the island chain. Stay tuned.
South swell will continue trend a bit lower today before another small background south swell fills in on Thursday with slight increasing trends expected on Friday and Saturday. A slightly larger, medium period south-southeast swell will arrive by early next week.
East facing shores will remain small over the next week, with a potential for a small north swell wrap by Sunday.
HFO Watches/Warnings/Advisories
None.
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Data Courtesy of NOAA.gov