Glenn James
Hawaii Weather Today
Creator, Author, and Administrator for over 30 years+

 

>>> I’m flying from Kahului, Maui to Portland, Oregon today, and from there down to Bend, Oregon…beginning my Autumn working vacation. Thus, I won’t be able to do my next updates until I get to my friend Bob’s place in Bend, which should be around 830pm HST this evening. I will continue doing my regular daily updates beginning Friday morning.

 

The latest update to this website was at 840am Thursday morning HST


Here are the latest 24-hour precipitation totals (inches) for each of the islands Thursday morning: 

1.32  Mount Waialeale, Kauai
0.42   Manoa Lyon Arboretum, Oahu
0.12  Puu Alii, Molokai
0.00  Lanai
0.63  Puu Kukui , Maui
1.13  Kulaimano, Big Island


The following numbers represent the strongest wind gusts (mph) Thursday morning:

10  Puu Lua, Kauai – NE
23  Oahu Forest NWR, Oahu – NE
20  Anapuka, Molokai – NE
20  Lanai 1, Lanai – NE
20  Honolua, Maui – SE
18  Pali 2, Big Island – NE


Hawaii’s Mountains – Here’s a link to the live webcam on the summit of our tallest mountain Mauna Kea (~13,800 feet high) on the Big Island of Hawaii. Here’s the webcam for the (~10,023 feet high) Haleakala Crater on Maui. These webcams are available during the daylight hours here in the islands, and at night whenever there’s a big moon shining down. Also, at night you will be able to see the stars, and the sunrise and sunset too…depending upon weather conditions.


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Big Blue…click twice for largest version

 

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 Cold front far northwest…thunderstorms in the deeper tropics

 

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Localized Showers 

 

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Please open this link to see details on any current Watches, Warnings and Advisories noted above




~~~ Hawaii Weather Narrative ~~~

 

Glenn’s Thursday comments:  I’m at home here in upper Kula, Maui, Hawaii

433am, it’s mostly clear here at my place, the low temperature was 53.5 degrees, relative humidity is 80%…with calm winds

 

Here’s the NOAA Climate Prediction Center’s Hawaii seasonal outlook: Hilo, Kahului, Honolulu and Lihue each a 75% probability of below-normal three-month rainfall totals for December 2026–February 2027

 

Hawaii’s Weather Highlights…as of Thursday morning: The high pressure system north of Hawaii will slowly drift eastward, as a low pressure system sets up north of the island chain by Friday. Moderate trade winds will continue a weakening trend producing hybrid trade wind and sea breeze wind flow each day lasting into early next week. Brief passing showers will drift into the islands on the easterly trade winds. Any showers will tend to favor windward mountain areas during the overnight to early morning hours.

A more significant change to our weather pattern continues to evolve for early next week from Tuesday through Wednesday. Deeply unstable tropical moisture moving across the state will bring the potential for heavy rain and thunderstorms affecting all islands.

Weather Narrative…as of Thursday morning: Satellite imagery shows a weak upper level low over the state causing unsettled cloud bands to develop across our area, producing brief passing showers as these clouds are lifted up over windward mountain ranges. Drier diurnal weather trends remain in the forecast for the later morning to afternoon hours each day. Expect these conditions to continue through the weekend.

The high pressure system currently north of the state will slowly drift eastward away from the islands, as a low pressure system takes its place just north Hawaii. This pressure pattern change will weaken the large scale trade winds through the weekend, and allow a hybrid trade wind afternoon sea breeze wind flow to expand in coverage along the sheltered western mountain slopes of all islands.

A more significant change in our Hawaiian weather pattern is brewing from next week Tuesday onward, as a large, roughly 1,500 mile long band of deep tropical moisture moves northward over the islands. Expect warm and humid conditions during this time, due to the rising tide of tropical moisture. Model solutions over the past three days are showing two or three weak cyclonic circulations embedded within this cloud band. Converging winds and upward motions surrounding these embedded lows will provide the forcing mechanism to produce stronger convective heavy rain bands and possibly thunderstorms.

Some uncertainty remains in the forecast this far out, and the forecast challenge with this pattern lies in predicting the arrival timing of this deeply unstable cloud band, and predicting the intensity of these embedded low pressure systems and predicting their locations relative to the Hawaiian Islands. A medium confidence pattern at this point, with island by island weather impacts becoming clearer as the forecast time period grows shorter, and our model solutions improve.

A Hydrologic Outlook may be needed to cover the rising threats for heavy rain and flash flooding potential during this Tuesday to Wednesday time period. Please continue to closely monitor weather conditions, including the potential for flash flooding early next week, as this weather pattern will likely evolve over time.

Fire Weather:  The high pressure system north of Hawaii will slowly drift eastward, as a low pressure system sets up north of the island chain by Friday. Moderate trade winds will continue a weakening trend, producing hybrid trade wind and sea breeze wind flow each day lasting into early next week.

A more significant change to our weather pattern continues to evolve for early next week from Tuesday through Wednesday. Deeply unstable tropical moisture moving across the state will bring the potential for heavy rain and thunderstorms affecting all islands. The subsidence temperature inversion heights near Maui and the Big Island will remain in the 7,500 to 8,500 foot elevation range today.

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Here’s a near real-time Wind Profile of the Pacific Ocean – along with a Closer View of the islands / Here’s the latest Weather Map / Looping Surface Precipitation…through the next 8-days / Vog Map

 

Marine Conditions…as of Thursday morning: A surface low pressure system far north of the Hawaiian Islands will move southeast, becoming located due north of the state by Friday. This will push the high pressure that has brought consistent trades off to the east. Trades will weaken through Friday, then weak to moderate trades are forecast this weekend into early next week.

Forecast uncertainty increases beyond this point, as conditions across Hawaii will hinge on the uncertain evolution of a low pressure system developing west-southwest of the islands. A small, medium-period northwest swell arriving overnight will provide a small boost to surf along north-facing shores on Friday. A moderate, medium-period north-northwest swell will follow this weekend, likely pushing surf to moderate levels beginning late on Saturday and peaking on Sunday. A storm-force low near Kamchatka will quickly follow this up with a moderate, long-period west-northwest swell maintaining moderate surf for north and west-facing shores early next week.

Surf along south-facing shores will remain small before a series of small to moderate, south-southwesterly swells boosts surf heights to near to above seasonal average this weekend into early next week.

East-facing shores will see the trade wind swell dropping slightly as trade winds decrease, though a small, medium-period east swell originating from former Hurricane Trudy forecast to arrive today may help maintain east-facing surf into the weekend.

 

>>> Highest Temperature Wednesday, October 21, 2026 – 96 degrees at Coolidge, AZ


>>> Lowest Temperature Wednesday, October 21, 2026 – 16 degrees near Bynum, MT

 

Big Island Nature Photography Tips from CJ Kale


World-wide Tropical Cyclone Activity

 



>>> Here’s a link to the latest Pacific Disaster Center’s Weather Wall



Atlantic Ocean:

Subtropical cyclone Josephine…is located 420 miles south-southwest of Halifax, Nova Scotia 

JOSEPHINE MOVING NORTHEASTWARD ACROSS THE NORTHWESTERN ATLANTIC…EXPECTED TO BECOME A POWERFUL EXTRATROPICAL CYCLONE THIS AFTERNOON OR TONIGHT

According to the NHC advisory number 4

The storm is moving toward the northeast near 12 mph, and this motion, along with an increase in forward speed, is expected to continue into tonight. A gradual turn toward the east is forecast on Friday and into the weekend. On the forecast track, Josephine should move away from the United States and remain south of Nova Scotia and Newfoundland during the next couple of days. Maximum sustained winds are near 65 mph with higher gusts. Some additional strengthening is forecast through the day today while Josephine begins to transition to an extratropical cyclone. Josephine is expected to become a powerful extratropical cyclone with hurricane-force winds tonight or early Friday. Winds of 40 mph extend outward up to 415 miles from the center. The estimated minimum central pressure is 988 mb (29.18 inches).

cone graphic

 

>>> Subtropical Central Atlantic:

A trough of low pressure located several hundred miles to the east-southeast of Bermuda is producing a large area of disorganized showers and thunderstorms. Some development of this system is possible during the next day or two while it moves slowly north-northeastward. Upper-level winds are forecast to become too strong for further development by the weekend.

* Formation chance through 48 hours…low…10 percent
* Formation chance through 7 days…low…10 percent


Caribbean Sea: There are no active tropical cyclones


Gulf of America: There are no active tropical cyclones

 

Northeast Pacific:

Tropical Cyclone 22E (Vance)…is located 680 miles south-southeast of Manzanillo, Mexico

VANCE GETTING STRONGER WELL SOUTH OF MEXICO

According to the NHC advisory number 3

Vance is moving toward the northwest near 3 mph, and a slow northwest to north-northwest motion is expected for the next few days. Satellite imagery indicate that the maximum sustained winds have increased to near 60 mph with higher gusts. Vance is forecast to become a hurricane tonight and could become a major hurricane by the weekend. Tropical-storm-force winds extend outward up to 90 miles from the center. The estimated minimum central pressure is 997 mb (29.44 inches).

cone graphic

 

Central North Pacific: There are no active tropical cyclones

>>> Western Central Pacific:

An area of low pressure is forecast to form near the International Date Line, a few hundred miles west-southwest of Johnston Atoll late this weekend or early next week. Environmental conditions appear conducive for some gradual development thereafter while the system moves generally eastward to east-northeastward.

* Formation chance through 48 hours…low…near 0 percent
* Formation chance through 7 days…low…30 percent

 

Northwest Pacific Ocean:

Tropical Cyclone 29W (Champi)…is located approximately 356 NM south-southwest of Kadena AB

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Southwest Pacific Ocean: There are no active tropical cyclones

 

North and South Indian Oceans / Arabian Sea: 

South Indian Ocean

Tropical Cyclone 02S (Agueda)…is located approximately 687 NM east of Dar Es Salaam, Tanzania 

 

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Here’s the link to the Joint Typhoon Warning Center (JTWC)



Interesting:  Microplastics Concentrations in the Truckee River Surge During High Spring Flows, New Study Finds

The ubiquitous plastics of modern life are degrading into tiny fragments and littering Earth’s landscapes and waterways. Scientists are starting to examine and measure this phenomenon to better understand how microplastics move through the environment and ultimately impact human and environmental health.

A new study focuses on the Truckee River, which stems from the clear blue waters of Lake Tahoe and traverses through Reno and Sparks, Nevada, before reaching Pyramid Lake. The research sought to illuminate the concentrations and types of plastics accumulating throughout the river — which supplies drinking water to nearly half a million people.

Published September 15th in ACS EST Water, the research was led by Hannah Lukasik, former master’s student at DRI and the University of Nevada Reno. She was mentored by Monica Arienzo, Director of DRI’s Microplastics and Environmental Chemistry Lab.

The group sampled microplastics at several sites upstream and downstream of Reno, Nevada, in fall 2022 and spring 2023. Microplastic concentrations were nearly ten-fold higher in spring (mean 3.7 microplastics/liter) than in fall (mean 0.4 microplastics/liter), when higher spring flows are likely flushing them from the landscape and river bottom.

Polyethylene (used for things like plastic shopping bags, milk jugs, and plastic wrap) and polypropylene (a sturdier plastic used for things like medical equipment, storage totes, and automotive parts) were the dominant plastics identified. The research demonstrates that reducing single-use plastic throughout the Truckee River Basin is critical for protecting the river’s water quality.

Read More: Desert Research Institute

Microplastic sampling along the Truckee River.