Photo credit: Jason Weingart
west kauai
The rest of the day: Mostly cloudy. Breeze. There will be scattered showers in the morning and scattered showers in the afternoon. The highest point near the coast is about 89 degrees and the highest point above 3,000 feet is about 76 degrees. East winds reaching 20 mph. The chance of rain is 50%.
tonight: Mostly cloudy. Lows near the coast are about 72 degrees and above 3,000 feet above sea level are about 61 degrees. Northeast winds reaching 15 mph, becoming around 10 mph after midnight.
Wednesday: Mostly sunny. There will be isolated showers in the afternoon. Highs will be around 90 degrees near the coast and around 76 degrees above 3,000 feet. Northeast wind gusts as high as 10 mph, becoming westerly in the afternoon. The chance of rain is 20%.
South Kauai
The rest of the day: Mostly cloudy. Breeze. There will be scattered showers in the morning and scattered showers in the afternoon. High temperature 80 to 88 degrees. The chance of rain is 50%.
tonight: Mostly cloudy with showers. The lowest temperature is about 72 degrees. The chance of rain is 20%.
Wednesday: Partly sunny with scattered showers in the morning, mostly sunny in the afternoon. Highest temperature 81 to 88 degrees. The chance of rain is 20%.
kauai mountains
The rest of the day: Mostly cloudy. Breeze. There will be more showers in the morning and scattered showers in the afternoon. High points in the valley range from 74 to 88 degrees, and above 4,000 feet it ranges from 62 to 68 degrees. East wind 10 to 20 mph. The chance of rain is 70%.
tonight: Mostly cloudy with scattered showers. Lowest temperatures range from 66 to 72 degrees in the valley and around 58 degrees above 4,000 feet. East wind 10 to 15 mph. The chance of rain is 50%.
Wednesday: Partly sunny. There will be scattered showers in the morning and scattered showers in the afternoon. Highest temperatures in the valley above 4,000 feet range from 75 to 88 degrees, with highs from 63 to 69 degrees. Northeast wind 10 to 15 mph. The chance of rain is 50%.
North Kauai
The rest of the day: Mostly cloudy. There will be more showers in the morning and scattered showers in the afternoon. Highest temperatures will be 78 to 90 degrees. The chance of rain is 60%.
tonight: Mostly cloudy with scattered showers. Low pressure 66 to 74 degrees. The chance of rain is 40%.
Wednesday: It will be partly sunny with scattered showers in the morning, and mostly sunny with scattered showers in the afternoon. High temperatures will range from 78 to 90 degrees. The chance of rain is 40%.
East Kauai
The rest of the day: Mostly cloudy. There will be more showers in the morning and scattered showers in the afternoon. Highest temperature 75 to 86 degrees. The chance of rain is 70%.
tonight: Mostly cloudy with scattered showers. Low pressure 66 to 76 degrees. The chance of rain is 50%.
Wednesday: It will be partly sunny with scattered showers in the morning, and mostly sunny with scattered showers in the afternoon. High temperature 75 to 87 degrees. The chance of rain is 40%.
renew
The forecast has been updated with an increase in PoP on the windward slope today and has driven some of the increase in wind speeds during the first 36 hours. This is consistent with the latest high-resolution model data, which shows wind speeds will remain slightly higher than initially expected, and radar support for higher PoP in the short term, which is also reflected in the model.
summary
High pressure will snake its way northwest of the island and weaken over the next few days. Winds will weaken later today and then weaken further during the second half of the week. Weather conditions are stable and rainfall remains light.
aviation
Breezy trade winds will continue today and are expected to ease slightly tonight. Trade wind showers will continue to bring MVFR cigs/vsbys to windward areas into the early morning hours, with conditions expected to improve by this afternoon.
AIRMET Sierra is now in effect for mountain shelters in windward areas of Kauai, Oahu, Molokai and Maui. Later this morning, this AIRMET may need to be expanded to include the large windward islands.
AIRMET Tango remains effective for moderate low-level turbulence over all island terrain and downwind. The AIRMET may still remain today.
ocean
The high pressure system northwest of the island continues to drift westward. As a low pressure system establishes northeast of the island chain, the ridge axis in the northern part of the state will weaken and move south. Trade winds will continue to weaken on Friday. A Small Craft Advisory (SCA) remains in effect throughout the afternoon for typically windy areas around Maui County and the Big Island. The SCA may be canceled tonight as wind speeds continue to trend downward.
Small background energy from south-southwest swells (200 degrees) will continue along south-facing shores during the first half of the week. A compact storm low has been moving eastward between 170 and 150 degrees along latitudes 25 to 30 degrees south over the past few days. This storm should produce a moderate southward surge that will peak on Thursday, peak on Friday, and slowly decrease over the weekend. Surfs along south facing shores are likely to be near or above summer average (5 feet) Thursday into the weekend.
Surf along the East Coast will continue to be swell and slowly ease over the next few days as the trade winds die down. As the typhoon moved near Taiwan last week, minor background energy from the west-northwest may increase later today into Wednesday.
Previous discussion
/Published Tuesday, July 30, 2024 at 345 AM/
Soundings this morning show the inversion height increased by about a foot overnight and is now about 7 to 8 feet as a slightly above-average moisture field moves across the island chain. High clouds are moving over the state, with low clouds moving from east to west, concentrating clouds and showers in windward and mauka areas. Overnight rainfall totals in rainy areas of Kauai ranged from 0.1 to 0.78 inches. CIMSS satellite observations and model guidance show that the moisture field is filled with dry air behind it, with the inversion height dropping to about 4-6 feet this afternoon. Lower inversion heights and available humidity will further limit showers in windward and mauka areas, leaving most leeward areas fairly dry with fewer showers. The exception is the Big Island's Kona Slope, where afternoon sea breezes can produce scattered showers. This pattern is expected to continue throughout the week, with small fluctuations in inversion height and showers due to diurnal patterns and shifting moisture bands.
The development of low pressure over the far northeast of the island will lead to a weakening of the local pressure gradient in the future. Volume will decline accordingly, falling into moderate territory later today, and may become lighter in the second half of the week as apparent temperatures rise accordingly.
Aviation…Breezy trade winds will continue today and are expected to weaken slightly tonight. Trade wind showers will continue to bring MVFR cigs/vsbys to windward areas into the early morning hours, with conditions expected to improve by this afternoon.
AIRMET Sierra is now in effect for mountain shelters in windward areas of Kauai, Oahu, Molokai and Maui. Later this morning, this AIRMET may need to be expanded to include the large windward islands.
AIRMET Tango remains effective for moderate low-level turbulence over all island terrain and downwind. The AIRMET may still remain today.
Ocean… The high pressure system northwest of the islands continues to drift westward. As a low pressure system establishes northeast of the island chain, the ridge axis in the northern part of the state will weaken and move south. Trade winds will continue to weaken on Friday. A Small Craft Advisory (SCA) remains in effect throughout the afternoon for typically windy areas around Maui County and the Big Island. The SCA may be canceled tonight as wind speeds continue to trend downward.
Small background energy from south-southwest swells (200 degrees) will continue along south-facing shores during the first half of the week. A compact storm low has been moving eastward between 170 and 150 degrees along latitudes 25 to 30 degrees south over the past few days. This storm should produce a moderate southward surge that will peak on Thursday, peak on Friday, and slowly decrease over the weekend. Surfs along south facing shores are likely to be near or above summer average (5 feet) Thursday into the weekend.
Surf along the East Coast will continue to be swell and slowly ease over the next few days as the trade winds die down. As the typhoon moved near Taiwan last week, minor background energy from the west-northwest may increase later today into Wednesday.
HFO Observations/Warnings/Recommendations
A small craft advisory is in effect for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, leeward waters of the Big Island, and waters southeast of the Big Island until 6pm HST tonight.
Data provided by NOAA.gov
