Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Mostly sunny with isolated showers. Highs around 89 near the shore to around 77 above 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 69 to 74 near the shore to around 60 above 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Saturday: Mostly sunny with isolated showers. Highs around 88 near the shore to around 76 above 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Isolated showers. Highs around 86. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with scattered showers. Lows 67 to 73. Northeast winds around 15 mph. Chance of rain 50 percent.

Saturday: Breezy. Partly sunny with numerous showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs around 85. Northeast winds 15 to 20 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Breezy. Partly sunny with isolated showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs 76 to 83 in the valleys to around 67 above 4000 feet. East winds 10 to 20 mph. Chance of rain 30 percent.

Tonight: Breezy. Partly cloudy with scattered showers in the evening, then mostly cloudy with numerous showers after midnight. Lows 60 to 65 in the valleys to around 55 above 4000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Saturday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 75 to 82 in the valleys to around 66 above 4000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

North Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Isolated showers. Highs 79 to 88. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with scattered showers. Lows 63 to 73. East winds 10 to 15 mph. Chance of rain 50 percent.

Saturday: Mostly sunny with scattered showers. Highs 78 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Isolated showers. Highs 79 to 87. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows 61 to 75. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Saturday: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 78 to 86. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Moderate to breezy trade winds will last into early next week. Hurricane Calvin, currently in the East Pacific, is expected to move into the Central Pacific Basin late Sunday. Calvin or its remnants will likely impact the state beginning next Tuesday, but it is too early for details.

Discussion

High pressure far north of the main Hawaiian Islands will keep moderate to breezy trade winds blowing across local waters into the weekend. Satellite loop shows scattered low clouds across most areas, with scattered to patchy broken low clouds embedded within trade flow across windward waters. Radar shows little or no shower activity. Overnight soundings depict a dry and stable airmass, with about an inch of PW and positive lifted index values. Strong inversions between 3500 and 4500 feet cap cloud development and act to limit rainfall. Thin high clouds streaming northeastward across the islands mark the eastern flank of an upper trough northwest of the islands.
Models show typical trade wind showers gradually returning through the weekend, ending the dry pattern we are in. Scattered showers will favor windward areas, with isolated showers expected over leeward areas. Overall, it should be a fair weekend with moderate to locally breezy trade winds. High clouds should decrease late this weekend into early next week.
We continue to monitor Hurricane Calvin in the East Pacific, which is expected to cross 140W into the Central Pacific Basin late Sunday as a weakening tropical storm. It is too early to specify details regarding impacts to the main Hawaiian Islands from Calvin or its remnants. However, impacts could begin as early as Tuesday into Wednesday of next week. Impacts to the state could include high surf, heavy rain, strong winds, or all of the above. All interests should monitor the latest public advisories issued by the National Hurricane Center, in Miami, Florida under WMO header WTPZ33 KNHC.

Aviation

Moderate to locally breezy trade winds and stable atmospheric conditions will likely persist today. There are scattered low clouds with a few showers embedded within the low-level trade wind flow. This may produce brief periods of MVFR conditions along some windward facing sections this morning. Otherwise, expect VFR conditions to prevail across most of the state today.
AIRMET Tango remains in effect for Tempo moderate low-level turbulence leeward of the higher terrain on all islands. This AIRMET will likely continue through this afternoon due to the relatively strong trade winds. No additional AIRMETs are anticipated at this time.

Marine

The current moderate to locally strong easterly trades are expected to slightly weaken into Saturday then restrengthen on Sunday into the fresh to strong wind speed range. The Small Craft Advisory remains in effect for most of the waters and channels around Maui and Hawaii Counties.
Hurricane Calvin currently in the eastern Pacific, will cross into the Central Pacific basin at 140W longitude from Sunday night into Monday morning as a weakening Tropical Storm, and then approach Hawaiian waters from Monday through Wednesday. Although confidence in specific detailed impacts remains fairly low at this time, all interests should monitor the latest advisories issued by the National Hurricane Center in Miami, Florida under WMO header WTPZ23 KNHC.
Surf along south facing shores will slowly decline today with mainly background level south-southwest and southeast swells expected through early next week. Surf along east facing shores will remain rough and choppy each day through the weekend. An upward trend may develop by Sunday due to a medium period easterly swell arriving from Calvin. Details beyond this will highly depend on both the intensity and track of Calvin as the cyclone approaches the islands early next week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Saturday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov