Hawaii County climate forecast is July 21, 2021

Hilo

Today: a few showers. Partly sunny, with a high near 82. Calm wind blowing 5 to 9 miles per hour from east-northeast in the morning. The probability of precipitation is 50%. New rainfall levels of less than a tenth of an inch possible.

Tonight: Showers likely. Mostly cloudy, with a low of about 67. Northeast wind with about 10 km / h becomes calm. The probability of precipitation is 60%. New rainfall levels of less than a tenth of an inch possible.

Thursday: Showers likely, mostly before noon. Partly sunny with a high near 81. Northeast winds 3 to 8 mph. The probability of precipitation is 60%. New rainfall levels of less than a tenth of an inch possible.

Kona

Today: A few showers after noon. Partly sunny, with a high near 79. West-southwest winds 3 to 8 mph. The probability of rainfall is 20%.

Tonight: A few showers before midnight. Partly cloudy, with a low of about 67. East winds 3 to 8 mph. The probability of precipitation is 20%.

THE ARTICLE CONTINUES BELOW THE ADVERT

Thursday: A few showers after noon. Mostly sunny, with a peak near 79. Calm wind that blows in the morning at about 10 km / h from west-southwest. The probability of precipitation is 30%. New rainfall levels of less than a tenth of an inch possible.

Waimea

THE ARTICLE CONTINUES BELOW THE ADVERT

Today: a few showers. Mostly cloudy, with a high near 76. Windy, with northeasterly winds of 18 to 23 mph, with gusts of up to 32 mph. The probability of precipitation is 50%. New levels of precipitation between a tenth and a quarter of an inch are possible.

Tonight: A few showers. Mostly cloudy, with a minimum of about 59. Breeze, with a northeasterly wind of about 35 km / h, with gusts of up to 50 km / h. The probability of precipitation is 50%. New amounts of precipitation between a quarter and a half inch are possible.

Thursday: A few showers. Partly sunny, with a high near 75. Windy, with northeasterly winds of 18 to 23 mph, with gusts of up to 32 mph. The probability of precipitation is 50%. New amounts of precipitation between a quarter and a half inch are possible.

Kohala

THE ARTICLE CONTINUES BELOW THE ADVERT

Today: Occasional showers. High near 67. Windy, with easterly winds 22 to 30 mph, with gusts up to 44 mph. The probability of precipitation is 80%. New rainfall levels of less than a tenth of an inch possible.

Tonight: Occasional showers. Low around 54. Windy, with an easterly wind of 28 to 30 mph, with gusts of up to 44 mph. The probability of precipitation is 80%. New rainfall levels of less than a tenth of an inch possible.

Thursday: Occasional showers. High near 66. Windy, with an easterly wind of 25 to 45 mph, with gusts of up to 41 mph. The probability of precipitation is 80%. New rainfall levels of less than a tenth of an inch possible.

Southern big island

Today: A few showers before noon. Mostly sunny, with a peak near 81. Windy, with easterly winds of 23 to 42 mph, with gusts of up to 54 mph. The probability of precipitation is 20%.

Tonight: A few showers. Partly cloudy, with a low point of 74. Windy, with an east-northeast wind of 24 to 42 km / h, with gusts of up to 54 km / h. The probability of precipitation is 20%.

Thursday: single showers. Mostly sunny, with a high near 80. Windy, with an easterly wind of 25 to 45 mph, with gusts of up to 60 mph. The probability of precipitation is 20%.

feedback

Today: Showers likely, mostly before noon. Mostly cloudy, with a peak near 79. Breeze, with a north-northeast wind of 10 to 24 km / h, with gusts of up to 34 km / h. The probability of precipitation is 60%. New levels of precipitation between a tenth and a quarter of an inch are possible.

Tonight: Showers likely. Mostly cloudy, with a low of around 65. North winds from 10 to 23 km / h, with gusts of up to 30 km / h. The probability of precipitation is 70%. New levels of precipitation between a tenth and a quarter of an inch are possible.

Thursday: Showers likely, mostly before noon. Mostly cloudy, with a high near 78. Northeasterly winds 10 to 13 mph. The probability of precipitation is 70%. New amounts of precipitation between a quarter and a half inch are possible.

Waikoloa

Today: Mostly sunny, with a high near 83. Windy, with east-northeast winds of 18 to 45 mph, with gusts of up to 40 mph.

Tonight: Partly cloudy, with a minimum of about 68. Breezes, with east-southeast winds of 16 to 21 mph, with gusts of up to 45 mph.

Thursday: Sunny, with a high near 83. Breeze, with an east-northeast wind of 18 to 35 km / h, with gusts of up to 50 km / h.

summary

Windy trade winds will concentrate low clouds and showers over windward and mauka areas until Saturday, especially at night and in the early morning hours. Some short showers may also occur in some leeward stretches. Widespread showers are possible in parts of the state from Saturday night or Sunday.

discussion

Two 1035 mb surface high pressure systems are located near 42N 166W and 40N 154W, approximately 1,430 miles north-northwest of Lihue and 1,300 miles north-northeast of Lihue, respectively. The tight pressure gradient south of these features is driving breezy trade winds across the state this morning. At altitude, west of Kauai, remains a broad upper trough of the troposphere. A west-southwest to east-northeast subtropical jet stream is also located near the state. According to satellite images this morning, this jet is quickly transporting cirrus clouds over the island chain. In addition, satellite imagery and radar reflectance data show scattered to fractured low clouds with embedded scattered showers pouring into the windward sides of most of the islands. Some of these showers also reach the leeward sections of some of the smaller islands.
The forecasts show that the breezy trade winds will last until early Thursday morning. The trade wind inversion is expected to weaken slightly at low levels, but generally remain fairly shallow, pushing 6 to 7 thousand feet down. The low-level trade wind flow will continue to carry low clouds and showers to windward and mauka sections of the state, particularly during the night and early morning hours. The gusty voyages will also carry a few short showers to some leeward stretches of the smaller islands. Clouds and showers will develop each afternoon and last into the evening hours over parts of the leeward Big Island.
The former Felicia Tropical Depression, now a flagging residual low located about 860 miles east-southeast of Hilo, is moving west-southwest at about 25 miles per hour. With this depression associated with the former Felicia passing south of the area in a few days, the gradient is likely to worsen across the state. This is expected to result in the trade winds remaining airy towards the end of the current work. In addition, recent global model results continue to suggest that some peripheral moisture in the 800-700 mb layer associated with the former Felicia could reach parts of the state later this week. Predictive modeling shows that as some of this moisture is distributed across the state, a slight decrease in mean stability can also occur. The current forecast indicates that there may be an increase in showers from Thursday to Friday in some sections of windward wind, especially on the Big Island.
Looking ahead to the weekend, the remnants of the former East Pacific Tropical Cyclone Guillermo are expected to reach the forecast area in the second half of the coming weekend. The consensus of the model guidelines seems to indicate that the deepest tropical moisture associated with the former Guillermo could pass right by the north of the state. Since that was more than 4 days ago, there is still a lot of uncertainty in the weekend forecast. The current forecast shows a slight weakening of the trade wind speeds until Sunday. In addition, wet trade wind conditions will develop from Saturday night through Monday morning. Heavy rains are not foreseen in the current forecast for this weekend.

aviation

A strong high pressure ridge north of the Hawaiian Islands will continue to generate breezy trade winds in the region for at least the next few days. Expect transient showers mainly over the windward and mountainous areas of each island with brief periods of MVFR conditions favoring the night until the wee hours of the morning. Less cloud cover and showers are forecast over the leeward areas of each island. Such strong wind speeds will also generate moderate turbulence over and immediately south through west of the island mountains. A jet stream in the upper atmosphere over the region will also create moderate turbulence from FL350 to FL450.
AIRMET Sierra in effect for mountain obscurations above 020 for northern and eastern sections of Kauai, Oahu, Maui and the Big Island. This AIRMET can last until the early hours of the morning.
AIRMET Tango in force for moderate turbulence above and immediately south through west of the Inselbergs.
AIRMET Tango in force for moderate turbulence in the entire region from FL350 to FL450.

marine

Strong high pressure lies north of the state and generates fresh to locally strong trade winds over the area. For the typically windy waters around Maui County and the Big Island, a Small Craft Advisory remains in effect and has been extended to Kauai Northwest Waters, Oahu Leeward Waters, Kaiwi Channel and Maui County Leeward Waters. Expect these conditions to last through the weekend.
The brief, choppy surf will dominate the wave spectrum for the remainder of the week and until early next week as long easterly winds blow over and against the state. A series of small southerly swells will keep the surf on the small side throughout the forecast period. North facing banks can see some trade wind swell wraps, and west facing banks can see some south swell wrap. No further significant swells are expected.

HFO watches / warnings / notices

Small boat advice through Thursday 6 a.m. HST for Kauai Northwest Waters, Oahu Leeward Waters, Kaiwi Channel, Maui County Leeward Waters, Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Big Island Now Weather is brought to you by Blue Hawaiian Helicopters.

Check out their Big Island Helicopter Tours today!

Data courtesy of NOAA.gov

Comments are closed.