Glenn James
Hawaii Weather Today
Founder and maintainer for 30 years 

 

The latest update to this website was at 109pm Monday (HST)

 

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

1.81  Mount Waialeale, Kauai
1.83  Tunnel RG, Oahu
0.10  Puu Alii, Molokai
0.10   Lanai City, Lanai
0.19   Hanaula , Maui
0.07  Hilo AP, Big Island

The following numbers represent the strongest wind gusts (mph) as of Monday afternoon:

21  Port Allen, Kauai – SE
22  Honouliuli, Oahu – SE
24  Makapulapai, Molokai – E
12  Lanai 1,  Lanai – SW
30  Na Kula, Maui – ESE
25  South Point, Big Island – ENE

Hawaii’s Mountains – Here’s a link to the live webcams on the summit of our tallest mountain Mauna Kea (~13,800 feet high) on the Big Island of Hawaii, and atop the Haleakala Crater (~10,023 feet) 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 cold front northwest…high clouds coming in from the west

 

https://cdn.star.nesdis.noaa.gov/GOES18/ABI/SECTOR/hi/GEOCOLOR/20260961410-20260962200-GOES18-ABI-HI-GEOCOLOR-600x600.gif

Low clouds arriving along the windward sides  

 

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…some heavy 

 

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 Bend, Oregon on a working vacation.

421am Hawaii time, I’m here at my friend Bob’s house. It’s clear with high cirrus clouds, with a 41 degree low. BTW, when I say Hawaii time, it is 3-hours later here in Oregon.

 

>>> Highest Temperature Sunday, April 5, 2026 – 98 degrees near Winterhaven, CA
>>> Lowest Temperature Monday, April 6, 2026 – 6 degrees at Peter Sinks, UT

 

Hawaii’s Broad Brush Weather Overview…as of 949am Monday:  Mostly dry and pleasant trade wind weather will continue, with brief passing showers favoring windward and mountain areas. A significant pattern change is then expected by Tuesday, as an upper disturbance and surface low pressure evolve northwest of the islands. This system is expected to draw deep tropical moisture northward over the state, leading to an extended period of southerly winds, increased chances for widespread rainfall, and renewed flooding concerns from the middle of the week through the weekend.

Short Term Update…as of 948am Monday: Instability will increase tonight into Tuesday across the western portion of the state, with some possible enhanced showers reaching Kauai by late tonight. Added a slight chance of thunder for Big Island on Tuesday afternoon due to increasing instability, daytime heating and sea breezes. Will assess widespread flash flood timing, locations and impacts today.

>>> Interesting Web blog: Mauka Showers…Is El Niño on Our Summer Bingo Card?

 

>>> HEAVY RAIN AND FLOODING POTENTIAL EXPECTED LATE TUESDAY INTO THE
WEEKEND...


A significant pattern change is expected to begin Tuesday as an
upper level disturbance and surface low pressure system evolve
northwest of the islands. This system is expected to draw deep
tropical moisture northward over the state, leading to an extended
period of moderate to breezy southerly winds, increasing chances for
widespread rainfall, and renewed flooding concerns from late Tuesday
through next weekend.

Now is a good time to prepare for possible flooding impacts:

-Clear gutters, storm drains, culverts, and drainage areas of debris
to improve water flow

-Move valuable items out of low-lying or flood prone areas

-Check pumps, generators, and emergency equipment to ensure they are
operational

-Take stock of emergency supplies, including food, water,
medications, flash lights, and backup power sources

-Review family emergency plans and check on neighbors and family.
especially those in flood-prone locations.

Residents living near stream, rivers, gulches, valleys, ravines and
flood-prone areas should remain especially alert and prepared to
move to higher ground if flash flooding develops.



Weather Details for the Hawaiian Islands…as of 341am Monday: A shortwave trough east of Midway will push rapidly to the east-southeast down the Northwest Hawaiian Islands. The high resolution models show the trough aloft should be close enough to begin locally enhancing showers over and near Kauai tonight in the southeast flow. A few of these might become briefly heavy as this leading shortwave gets close and mid-level temperatures cool for a while, but instability will still be limited at this point.

High pressure to the north will continue to bring some moderate trades to the islands, but a cold front northwest of the islands that is moving to the east will help to push the ridge closer to the islands. The result will be weakening winds that will begin to veer to a southerly direction. Tonight or Tuesday morning, a broad surface trough is expected to develops northwest of the islands, helping to reinforce the southeast to south winds from Tuesday through Wednesday.

This is about the time a series of shortwave troughs, like the one mentioned above, will begin to dig towards the islands. As background flow becomes more southerly, models remain in good agreement that deep tropical moisture will be drawn northward once again over the islands as early as Tuesday but especially by Wednesday. The increased moisture, combined with daytime heating, sea breezes, and a potent shortwave trough moving through, may even trigger some heavy showers over interior areas on Tuesday.

From Wednesday through the end of the week, there remains the potential for more widespread rainfall and flooding. Upper-level forcing is expected to strengthen as a strong shortwave rounds the base of the trough, potentially enhancing lift over the region, while low pressure organizes west of the islands. The combination of deep moisture, increasing large-scale forcing for ascent, and southerly winds (which could be gusty at times) all point towards yet another widespread and organized rainfall event for the state. In addition to the rainfall concerns during this period, some strong to severe thunderstorms along with gusty downsloping winds for north and windward sides of the islands can`t be ruled out.

Differences remain in the global models for the upcoming weekend, but the general consensus is that the active pattern could linger in the area. The ECMWF model clears out much of the state of the bulk of the rain, but the GFS continues the potential for rain across at least portions of the state through the weekend and beyond, where the deep moisture axis anchors.

As previous discussions have mentioned, one important consideration with this week`s rainfall is antecedent conditions. The islands experienced significant flash flood events in recent weeks, and despite several days of drier trade wind weather, soils remain vulnerable in many areas. As a result, any time period of higher rainfall rates could quickly lead to enhanced runoff, renewed rises in streams and reservoirs, and localized flash flooding concerns.

This system will continue to be closely monitored over the coming days, and additional adjustments to timing, duration, and impact messaging are possible as details become more clear.

 

Here’s a near real-time Wind Profile of the Pacific Ocean – Zoom Earth – along with a Closer View of the islands / Vog map animation / 8-Day Precipitation model

https://www.weather.gov/images/hfo/graphics/npac.gif

 

Hawaii’s Marine Environment…as of 341am Monday: Moderate to locally fresh trades will hold as high pressure far north of the islands moves slowly eastward. Winds will ease and shift southeasterly tonight through Wednesday, as a front stalls just west of the islands. The winds will turn more southerly and increase to moderate and strong levels on Thursday as a low pressure system develops along the stalled frontal boundary.

Small northwest swells will keep some small surf along north facing shores. A moderate long-period northwest swell will fill in tonight and Tuesday, giving more of a boost to north shore surf late Tuesday through Wednesday. A small, short period north-northeast swell will fill in during the day Tuesday before peaking Wednesday and subsiding Thursday. This overlap will make for some rough choppy conditions.

A small southerly swell will keep some small surf in place along south facing shores. A slightly larger, long-period south swell, will fill in tonight. This swell will give a more noticeable increase to south shore surf Tuesday and possibly reaching advisory levels by Wednesday, before slowly easing Thursday into the weekend. Strengthening southerly winds could make for rough choppy surf by later in the week.

East shore surf will remain small and below the seasonal average during the next 7-days, due to a lack of strong trade winds over and upstream of the islands, except for some wrap from the northerly swells.

 


World-wide Tropical Cyclone Activity

 

Atlantic Ocean:  There are no active tropical cyclones

Caribbean Sea:  There are no active tropical cyclones

Gulf of America:  There are no active tropical cyclones

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

 

Northeastern Pacific:  There are no active tropical cyclones

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

North Central Pacific: There are no active tropical cyclones

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

 

Northwest Pacific Ocean: There are no active tropical cyclones

 

Southwest Pacific Ocean: 

Tropical Cyclone 30P (Maila)…is located approximately 665 NM south of Kapingamarangi

https://www.metoc.navy.mil/jtwc/products/30P_061800sair.jpg

Tropical Cyclone 31P (Vaianu)…is located approximately 236 NM west-northwest of Suva, Fiji

https://www.metoc.navy.mil/jtwc/products/31P_061800sair.jpg

 

North Indian Ocean:  There are no active tropical cyclones

South Indian Ocean:  There are no active tropical cyclones

Arabian Sea:  There are no active tropical cyclones

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

 

>>> Here’s a link to the Pacific Disaster Center’s (PDC Global) Weather Wall website

 

Interesting: For at least one species, cigarettes might actually be good for health.

For at least one species, cigarettes might actually be good for health.

While smoking is a well-known carcinogen, what’s less appreciated is that scientists have observed some species of birds adding bits of cigarettes to their nests. Scientists in Poland say they have discovered one possible reason why: The cigarettes might be boosting the health of nestlings by warding off parasites.

“Our study indicates that cigarette butts may be used by urban blue tits as an opportunistic adaptive strategy, mimicking the function of aromatic plant materials in parasite control,” the scientists write in a paper published earlier this year in Animal Behavior.

Add this to the mountain of evidence about how species are finding clever adaptations to urban life in the Anthropocene. There are glaring examples, such as raccoons turning into suburban “trash pandas.” There are more subtle cases, such as bacteria that have evolved to feed on plastic.

Then there’s the Eurasian blue tit. The showy little songbird, which resembles a chickadee dipped in blue and yellow paint, is a common site in much of Europe. It’s already shown a knack for adapting to human surroundings, frequenting bird feeders and artificial birdhouses. In the 1920s, people in Britain discovered the birds were pecking through the foil covers of milk bottles delivered to doorsteps to feed on the thick layer of cream below.

More recently, scientists have observed a somewhat less wholesome habit. Blue tit nests are found to contain cigarette butts. Some of the birds have even been spotted building nests inside enclosed receptacles designed for people to throw away cigarette butts.

A group of Polish scientists at the University of ?ód?, who have a long-term project studying blue tits around that city, decided to try to figure out why these birds might be seeking out bits of trash contaminated with everything from arsenic to heavy metals.

One leading hypothesis was that the birds were using these butts as little pest repellents to ward off parasitic bugs such as mites, ticks and fleas that can infest nests and feed on the blood of young birds. In more natural settings, blue tits are known to add pieces of aromatic plants such as lavender and mint to their nests, and there is some evidence it improves nestling health. Scientists in Mexico have also found that house finches there appear to adorn their nests with cigarette butts to battle parasites such as ticks.

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