Glenn James
Hawaii Weather Today
Founder and maintainer for 30 years


The latest update to this website was 713pm Monday evening HST


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

0.43  Kalaheo, Kauai 
1.36  Kamehame, Oahu
1.61  Puu Alii, Molokai
0.74  Lanai City, Lanai
2.94   Kahakuloa, Maui
1.65  Keahuolu, Big Island


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

23  Barking Sands, Kauai – SE
30  Kuaokala, Oahu – SE
15  Makapulapai, Molokai – E
20  Lanai 1,  Lanai – SE
21  Nene Nest, Maui – SW 
21  Mauna Loa Obs, Big Island  


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.

https://weather.gc.ca/data/satellite/goes_gwdisk11_1070_100.jpg

Big Blue…click twice for largest version

 

https://cdn.star.nesdis.noaa.gov/GOES18/ABI/SECTOR/tpw/13/GOES18-TPW-13-900x540.gif

A deep area of low pressure far north…with thunderstorms southwest

 


https://cdn.star.nesdis.noaa.gov/GOES18/ABI/SECTOR/hi/GEOCOLOR/20261031710-20261040100-GOES18-ABI-HI-GEOCOLOR-600x600.gif

Multi-level clouds moving over the state 

 

https://radar.weather.gov/ridge/standard/HAWAII_loop.gif

https://radar.weather.gov/ridge/standard/PHKI_loop.gif

https://radar.weather.gov/ridge/standard/PHKM_loop.gif

Showers locally 

 

https://www.weather.gov/wwamap/png/hfo.png

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




~~~ Hawaii Weather Narrative ~~~

 

Glenn’s Monday comments:  I’m here in Vancouver, BC, Canada with my friend Bob, continuing on in my working vacation.

239pm Hawaii time, It’s partly cloudy here in Vancouver, although it has been cloudy most of the day. We had breakfast out again this morning at our favorite place called Cafe Zen. We took a hike later in the morning at Pacific Spirit Regional Park, and along the trail we got rained on, although it didn’t last long, nor was it too heavy. After we finished the hike we had lunch at Whole Foods, and then we came back to our place here in Kitsilano, and just hung out, worked and talked. We want to watch the Rachael Maddow show see what she says about the latest news. Then, we’re walking down to find some place to have dinner. We haven’t eaten a meal here at our place yet, even though it’s fully equipped.

 

>>> Interesting weather web blog – Mauka Showers…How Fast is a Flash Flood in Hawaii?

>>> Highest Temperature Monday, April 13, 2026 – 97 degrees at Rio Grande Village, TX
>>> Lowest Temperature Monday, April 13, 2026 –  11 degrees Lund, NV

 

Hawaii’s Broad Brush Weather Overview…as of 336pm Monday afternoon:  A line of light to moderate showers across the central portion of the state is expected to lift north and dissipate. Light and variable winds will favor some onshore sea breezes through mid-week. By the latter half of the weak, light east to southeast winds and quieter weather return to the forecast. This weekend may see a boost in showers as an upper level disturbance approaches from the northwest.

>>> Light rain or periodic showers hang on through the day.
>>> western 2/3rds of state.
>>> A widespread chance for return nuisance flooding over Kauai, Oahu and Maui County with very low rain amounts.

Weather Details for the Hawaiian Islands…as of 336pm Monday afternoon: A band of mostly light showers has shifted slightly east over the central islands, contrary to what most of the hi-res model guidance was showing this morning, which showed the line shifting westward. Most of the rainfall has been focused over Oahu and Maui County, with a few hundredths of an inch recorded at most locations since this morning.

For what it`s worth (and it may not be much based on what was already mentioned), hi-res model guidance suggests that shower activity will diminish as the current line lifts north and falls apart, then additional light to moderate showers may reorganize along another weakly convergent boundary near Kauai overnight, and persist in the vicinity through at least Tuesday.

For the latter part of the week, trades will try to return, but may have a hard time doing so as a nearly stationary surface trough forms and persists northwest of the state, making it hard for the high pressure to the northeast to take over the local winds. Overall, winds are expected to be light east to southeasterly. With light winds prevailing, and if diurnal heating is strong enough, land and sea breeze activity may bring interior showers during the day and partial clearing overnight for the rest of the island chain. Otherwise, isolated light showers will move in on the weak southerly flow for the west half, and on the southeasterly flow for the east half that will become light east to southeasterlies across the state for the latter part of the week.

With lots of deep moisture sticking around through the forecast period, a mix of low and high clouds will stick around, and it won`t take much to trigger shower development. Precipitable water values (PWats) are expected to remain between 1.8 and 2 inches through mid-week, before dropping slightly to 1.5 to 1.8 inches for the latter half. For reference, the average PWats for this time of year is around 1.2 inches.

This weekend, an upper level trough will dig down rather close to the state from the northwest. While most of the model guidance doesn’t do much with it at this point, it`s worth keeping an eye on to see if it will help to enhance shower activity over portions of the state, especially with ample moisture lingering and cooler temperatures moving in aloft.


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

 

Marine Environmental Conditions: A weak surface trough remains draped across the state, leading to pockets of light winds over the central islands. Winds may be stronger tonight when enhanced near island terrain, such as southeast near the Big Island or south near Kauai, before diminishing Tuesday. The surface trough weakens and lifts out the latter half of the week. High pressure begins to take over at the surface, causing gentle to moderate easterly trades to gradually develop across the Hawaiian coastal waters by this weekend.

A small, medium-period northwest swell has diminished, with small surf persisting along north and west facing shores due to a reinforcing pulse on Tuesday. Following this, northwest swell energy declines through the rest of the week.

A new south swell arrives on Tuesday, providing a boost to surf along south facing shores through mid-week, before gradually subsiding into the weekend. Surf along east facing shores will remain below seasonal average with lighter than average trade winds near and upstream of the islands forecast through next week.

 

r/pics - a rainbow over the ocean.

 Rainy weather locally


World-wide Tropical Cyclone Activity


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


>>> Atlantic Ocean: There are no active tropical cyclones

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

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

Here’s the link to the National Hurricane Center (NHC)

 

>>> Eastern Pacific: There are no active tropical cyclones

Here’s the link to the National Hurricane Center (NHC)

>>> Central Pacific: There are no active tropical cyclones

Here’s the link to the Central Pacific Hurricane Center (CPHC)

 

>>> Northwest Pacific Ocean:

Tropical Cyclone 04W (Sinlaku)…is located approximately 68 NM southeast of Saipan

https://www.metoc.navy.mil/jtwc/products/04W_140000sair.jpg

 

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

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



Interesting:  MIT Researchers Measure Traffic Emissions, to the Block, in Real-Time

A new study pieces together existing data sources in order to develop a detailed, dynamic picture of auto emissions.

In a study focused on New York City, MIT researchers have shown that existing sensors and mobile data can be used to generate a near real-time, high-resolution picture of auto emissions, which could be used to develop local transportation and decarbonization policies.

The new method produces much more detailed data than some other common approaches, which use intermittent samples of vehicle emissions. The researchers say it is also more practical and scales up better than some studies that have aimed for very granular emissions data from a small number of automobiles at once. The work helps bridge the gap between less-detailed citywide emissions inventories and highly detailed analyses based on individual vehicles.

“Our model, by combining real-time traffic cameras with multiple data sources, allows extrapolating very detailed emission maps, down to a single road and hour of the day,” says Paolo Santi, a principal research scientist in the MIT Senseable City Lab and co-author of a new paper detailing the project’s results. “Such detailed information can prove very helpful to support decision-making and understand effects of traffic and mobility interventions.”

Read More: Massachusetts Institute of Technology (MIT)