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

 

The latest update to this website was at 418am Thursday morning HST


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

0.16  Mount Waialeale, Kauai
0.64  Manoa Lyon Arboretum, Oahu
0.34  Puu Alii, Molokai
0.02  Lanai City, Lanai
0.81  West Wailuaiki, Maui
0.34  Upolu AP, Big Island


The following numbers represent the strongest wind gusts (mph) Wednesday evening: 

29  Port Allen, Kauai – E 
35  Kuaokala, Oahu – SW
27  Makapulapai, Molokai – E
m   Lanai – m
35  Kahului AP, Maui – NE
30  Puu Mali, Big Island – WSW


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 (out of operation). 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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 Thunderstorms southeast in the deeper tropics…potential tropical cyclone 01C southeast

 

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Low clouds arriving on the trade winds…high clouds southeast 

 

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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 Wednesday comments:  I’m at home here in upper Kula, Maui, Hawaii

454am, it’s mostly clear here in upper Kula with calm winds, and a low temperature at my place of 54 degrees…with the relative humidity 79%

337pm, sunny to partly sunny and dry here in Maui County, except for some showers along the windward sides…perhaps we could say the calm before the storm.

849pm, it’s cloudy here in upper Kula, and as such, the temperature here at my weather tower is mild mannered 66.9 degrees…with the relative humidity 79%

 

>>> I don’t know about you, but I’m making lots of ice in my freezer, that can stay in there if the power goes off this weekend, and enough that I can bring some of it into the refrigerator to keep my food from going bad. <<<

Potential Tropical Cyclone 01C…is located about 775 miles east-southeast of Hilo, Hawaii

cone graphic

Key Messages:

1. The disturbance is expected to become a tropical storm by Thursday night and strengthen while it moves west-northwestward near or over the Hawaiian Islands late this week and this weekend. Although it is too soon to specify the exact location and magnitude of impacts, residents should closely monitor the latest forecast updates and ensure that they have their preparedness plan in place.
2. Heavy rainfall associated with the Potential Tropical Cyclone will begin to impact the Big Island Friday, spreading westward across the island chain during the weekend. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain.

3. There is an increasing risk of wind and wave impacts in the Hawaiian Islands regardless of the exact track and intensity of the system. Hurricane or Tropical Storm Watches may be required for portions of the Hawaiian Islands early Thursday.

 

Hawaii’s Weather Highlights…as of Wednesday evening: Increased trade winds Thursday and Friday, combined with dry conditions will elevate the fire weather threat for the end of the work week. Most likely locations for any occasional showers will be over the windward and mountain areas through Friday. For the weekend. Residents and visitors should prepare now for potential tropical cyclone impacts this weekend.

Update: Latest satellite and radar imagery shows a few areas of low clouds and showers embedded within the trade winds moving into windward and mauka areas. Expect these to continue throughout the night, with some improvement expected again during the morning hours Thursday.

Meanwhile, episode 53 of lava fountaining in Halemauma’u at the summit of Kilauea began at 345pm. Following the beginning of episode 53, a plume of moderate tephra and gas was observed up to around 18,000 ft, moving southwest in lower levels and more westerly in higher levels. As of 830pm this evening, the plume height has decreased a bit, but GOES Ash RGB satellite imagery shows the plume moving west-northwest across the Big Island. Fountaining episodes typically last less than 12 hours, but ash can remain in the air longer depending on wind and weather.

As previous forecast discussions have mentioned, the main forecast concern for the next few days remains the development of Potential Tropical Cyclone One-C. In anticipation of critical new updates with each of the next few advisory packages issued by the National Hurricane Center (NHC), the NWS Honolulu will begin delaying the issuance of their typical forecast package products starting Thursday morning until after the release of NHC’s suite of products to incorporate the latest and most up-to-date information on Potential Tropical Cyclone One-C.

Weather Narrative..as of Wednesday evening:  Satellite imagery was indicating most of the shower activity was focused on Maui and Molokai, with rainfall gauges showing 0.10″ or less of accumulated rain. Occasional light showers are expected to continue through the evening. Mostly dry conditions are expected to continue through the rest of the work week. Those in windward and mountain areas will continue to see scattered showers at times through Friday.

The main forecast concern for late Friday through the weekend will be the development of Potential Tropical Cyclone One-C. The system has not moved much, and is still about 900 miles east-southeast of the Big Island. The National Hurricane Center is still forecasting it to develop into a Tropical Storm as early as Thursday morning.

The details of the forecast are still uncertain but impacts are expected to the state as early as Friday night and will continue through the weekend. Interests within the Hawaiian Islands should closely monitor for forecast updates and prepare for the potential impacts described below.

FIRE WEATHER… Fire weather concerns will increase on Friday ahead of any potential tropical cyclone`s arrival. Winds will begin to strengthen, while a dry and stable air mass with low relative humidity moves overhead. This combination of lower relative humidity and increasing wind speeds will likely lead to high wildfire risk.

STRONG AND GUSTY WINDS… Winds could strengthen further on Saturday, though the timing, direction, and magnitude of the strongest winds remain highly dependent on the eventual track and intensity of the system. Even if the center of the system remains away from the islands, the north semicircle of the storm will likely produce damaging winds. Due to the great uncertainty at this time, it is likely that the current forecast is under-doing winds at some locations, while potentially over-doing the winds at others. The specifics on winds impacts will become more clear as further development occurs.

HEAVY RAINFALL… This system could bring periods of heavy rainfall, particularly across east and southeast-facing slopes. Mountain enhancement could result in locally higher rainfall totals, where moist tropical flow interacts with island terrain. If heavier rainfall persists over the same locations, flash flooding and rapidly rising streams are possible. Again, the location of heaviest rain and any bands that would move through the islands will be highly dependent on the system’s track. The current forecast favors the Big Island and islands of Maui County as having the highest rainfall potential, but this is subject to refinement over the next few days as further development occurs.

LARGE AND ROUGH SURF… The developing system is expected to generate a large easterly swell as it moves northwestward across the Central Pacific. Surf will build along east-facing shores from east to west as the system approaches, with warning level surf possible into the weekend.

 

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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 Wednesday evening: High pressure to the far northeast will slowly drift into a position just north of the Hawaiian Islands into the weekend, producing moderate to locally strong trade winds across the region. A Small Craft Advisory (SCA) was extended in time through Thursday afternoon for the windier waters and channels around Maui and the Big Island.

The weather pattern may change significantly this weekend, as we continue to watch for a developing tropical cyclone currently in an area roughly 800-900 NM east-southeast of the Big Island. Marine interests should be prepared for potential tropical cyclone impacts to offshore and coastal marine waters starting Friday and lasting through the weekend.

Surf along south and west facing shores will continue to remain elevated as overlapping south swells continue to fill in around the islands today. Another moderate, long period south swell will fill in later today through Thursday, with swell energy peaking south shore surf heights into the High Surf Advisory range on Thursday. This south swell energy will then slowly fade into Saturday. In the long range surf outlook, the next decent boost in south swell energy may arrive by the end of next week (Aug 19th through 23rd).

Surf along east facing shores will continue to remain moderate and rough due to continued trade winds. Later in the week, the track of a developing tropical cyclone will dictate the potential for a large swell exceeding warning levels from the east to southeast direction.

Surf along north facing shores will remain flat to tiny through the week.

 

>>> Highest Temperature Wednesday, August 12, 2026 – 115 degrees near Tecopa, CA


>>> Lowest Temperature Wednesday, August 12, 2026 – 33 degrees near Bynum, MT

 

HAWAIIAN ISLANDS FINE ART PHOTOGRAPHY | Marlon Holden Fine Art


World-wide Tropical Cyclone Activity


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


>>> Atlantic Ocean:
 

Tropical Cyclone Cristobal…located about 610 miles west of the Azores

CRISTOBAL BECOMES A TROPICAL DEPRESSION AND IS EXPECTED TO DISSIPATE TODAY

According to the NHC advisory number 4…

The depression is moving toward the northeast near 16 mph, and this general motion is expected to continue through today. Maximum sustained winds are near 35 mph with higher gusts. Weakening is forecast, and Cristobal is forecast to dissipate later today. The estimated minimum central pressure is 1014 mb (29.95 inches).

 

Central Subtropical Atlantic:

Invest 92L

Showers and thunderstorms are showing signs of organization in association with a tropical wave located about 1000 miles east of the Lesser Antilles. This system will likely become a short-lived tropical depression during the next day or two as it moves westward across the tropical Atlantic. However, by late Friday, the system is expected to move into a region of strong upper-level winds and dry air, which should end its opportunity to develop. Interests in the Lesser Antilles should monitor the progress of this system as gusty winds and areas of heavy rain are possible Friday night and Saturday, regardless of development.

* Formation chance through 48 hours…high…80 percent
* Formation chance through 7 days…high…80 percent

 

Eastern Tropical Atlantic:

Invest 94L

A tropical wave located a few hundred miles south-southwest of the Cabo Verde Islands is producing disorganized showers and thunderstorms. Environmental conditions are forecast to be generally conducive for gradual development, and a tropical depression could form late this week or this weekend while the wave moves westward or west-northwestward across the eastern and central tropical Atlantic.

* Formation chance through 48 hours…low…30 percent
* Formation chance through 7 days…medium…50 percent

 

>>> Caribbean Sea: There are no active tropical cyclones

Tropical cyclone formation is not expected during the next 7 days.

>>> Gulf of America: There are no active tropical cyclones

Tropical cyclone formation is not expected during the next 7 days.

 

Northeast Pacific: 

Tropical Cyclone 08E (Hernan)…is located 1460 west of the southern tip of Baja California

TROPICAL DEPRESSION BECOMES TROPICAL STORM HERNAN OVER THE EAST PACIFIC

According to the NHC advisory number 2…

The depression is moving toward the west-northwest near 7 mph. A gradual turn to the west and southwest is expected over the next day or so. Maximum sustained winds are near 35 mph with higher gusts. Some slight strengthening is possible during the next day or so, and the depression could become a tropical storm by Thursday. Weakening is expected to begin by Friday. The estimated minimum central pressure is 1006 mb (29.71 inches).

 

Central North Pacific: 

Potential Tropical Cyclone 01C…is located about 835 miles east-southeast  of Hilo, Hawaii

DISTURBANCE FORECAST TO BRING HEAVY RAINFALL, HIGH WINDS AND DANGEROUS SURF TO THE HAWAIIAN ISLANDS STARTING LATE FRIDAY

According to the NHC advisory number 3…

The system is moving toward the west near 9 mph, and a westward to west-northwestward motion is expected over the next few days. On the forecast track, the center will be nearing the Hawaiian Islands by late Friday. Maximum sustained winds are near 40 mph with higher gusts, but the system still lacks organized shower and thunderstorm activity. The disturbance is forecast to become a tropical storm on Thursday, and additional strengthening is forecast thereafter.

* Formation chance through 48 hours…high…90 percent
* Formation chance through 7 days…high…90 percent 

 

>>> Northwest Pacific Ocean:

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Tropical cyclone 13W (Peilou)…is located approximately 827 NM north of Wake Island

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Tropical cyclone 16W (Nangka)…is located approximately 555 NM east-northeast of Iwo To

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>>> Southwest Pacific Ocean: There are no active tropical cyclones

>>> North and South Indian Oceans / Arabian Sea: There are no active tropical cyclones

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



Interesting: Drought is Reshaping the Spread of Infectious Diseases

From the American West to Europe, droughts are drying up rivers, fueling destructive fires and reshaping ecosystems. They are also changing the spread of infectious diseases, leading to surges in illnesses like cholera and West Nile virus around the world.

In a review paper published August 12 in Trends in Ecology & Evolution, CU Boulder ecologist, Pieter Johnson, and his collaborator, Tara Stewart Merrill at the Cary Institute of Ecosystem Studies, reveal how drier conditions could make humans and wildlife more vulnerable to certain infectious diseases, even though many parasites and disease-carrying organisms depend heavily on water to survive.

“Climate change isn’t simply making Earth warmer or drier,” said Johnson, distinguished professor in the Department of Ecology and Evolutionary Biology. “It is making droughts more variable and less predictable. That unpredictability is becoming one of the defining challenges for understanding and managing disease in natural ecosystems.”

Read More: University of Colorado at Boulder

Image: A pond in Shanahan Ridge in Boulder, Colorado. It has gone dry for the first time in many years this summer due to the lack of snow in the area last winter.