September 8, 2026

Hurricane Lowell is the most consequential item in today's brief, and Kauai County is under a hurricane warning rather than a watch. That changed since yesterday.

As of public advisory 48, a corrected advisory issued at 5:00 yesterday evening Hawaii time, Lowell was centered near 20.3 degrees north and 161.3 degrees west, about 170 miles southwest of Lihue and 230 miles west-southwest of Honolulu. Maximum sustained winds were 110 miles an hour with a minimum central pressure of 956 millibars, moving north-northeast at 18 miles an hour. That position came from Air Force Reserve Hurricane Hunter aircraft rather than from satellite estimate.

A hurricane warning is in effect for Kauai County, which includes both Kauai and Niihau, and for the Papahanaumokuakea Marine National Monument from Nihoa to French Frigate Shoals. A tropical storm warning is in effect for Oahu.

The difference between a watch and a warning is the difference between possible and expected. A hurricane warning means hurricane conditions are expected somewhere in the warning area, and the National Hurricane Center's own wording is that preparations to protect life and property should be rushed to completion. That is the strongest language in the product and it is not decorative.

The forecast track has the core of Lowell passing near or just west of Niihau overnight and into this morning, then turning northwest and slowing by early tomorrow after it passes the islands. Weakening is expected over the next several days, but the center expects Lowell to remain a hurricane as it passes the islands. Hurricane force winds extend out to 70 miles from the center and tropical storm force winds out to 175 miles. Lihue Airport had already reported sustained winds of 38 miles an hour with a gust to 49 at the time of the advisory.

The National Weather Service office in Honolulu issued the local warnings at 4:51 yesterday afternoon Hawaii time. Twenty five alerts were active across Hawaii when the national feed was read at 1:01 this morning Eastern time. Alongside the hurricane and tropical storm warnings, the set includes a tornado watch for Kauai until 4:00 this morning Hawaii time, high surf warnings until 6:00 this evening Hawaii time covering leeward and south facing shores from Kauai through the Big Island, and a flood watch through this afternoon covering Oahu, Maui County, and the Big Island as well as Kauai.

The rainfall numbers are the ones to sit with. The advisory calls for an additional 4 to 8 inches on Kauai with maximum storm totals of 24 inches possible, an additional 3 to 8 inches on the Big Island with isolated storm totals of 12 inches, and an additional 2 to 5 inches on Oahu and in Maui County with isolated totals of 10 inches. The center states this rainfall may produce significant flash flooding and mudslides, particularly in Kauai County and parts of the Big Island.

Storm surge is forecast at 2 to 4 feet above ground level in Kauai County, highest along the south coast of Kauai and on Niihau, and up to 1 foot on Oahu. The deepest water sits along the immediate coast to the right of the center, where surge arrives with large waves on top of it.

On the mainland, the heat is the story. Extreme heat warnings cover the Coachella Valley, the San Diego County deserts, and the San Gorgonio Pass near Banning from 10:00 tomorrow morning to 8:00 Friday evening Pacific time, with temperatures up to 110 and overnight lows in the mid 80s to low 90s. A separate warning covers Parker Valley and central La Paz County in Arizona along with the Palo Verde and Chuckwalla valleys in California from tomorrow through Friday, with afternoon temperatures of 102 to 111. A third covers Gila Bend, the Sonoran Desert National Monument, the Tonopah Desert, the Gila River Valley, Kofa, and southeast Yuma County in Arizona from 10:00 this morning to 8:00 Thursday evening Mountain time, with afternoon temperatures of 104 to 109.

Heat advisories cover the Orange County and San Diego County coastal areas from 10:00 this morning to 8:00 Thursday evening Pacific time, with highs of 85 to 95 and overnight lows in the mid 70s. The alert notes moderate to major HeatRisk and elevated overnight lows, which is the part that matters in a coastal area where many homes have no air conditioning.

California carries 23 active alerts in total, Arizona four, and Nevada none. The California set also includes a high surf advisory and a coastal flood advisory for the Orange and San Diego county beaches, with breaking waves of 4 to 7 feet and sets to 9 feet, dangerous rip and longshore currents, and minor evening coastal flooding on high tides. A frost advisory covers valleys in Modoc County, where lows near 31 are expected.

For Kauai the infrastructure question is the grid, and it is the reason the next two days matter more than the wind speed alone suggests.

Kauai runs on an island grid with limited redundancy. There is no neighboring utility to tie into. Restoration after a wind event depends on crews reaching poles on roads that may be blocked by debris or washed out by the same rain that is forecast. Sustained hurricane force wind with 24 inches of rain possible is a combination that damages the network and then makes it hard to reach.

The practical consequence for a household on Kauai or Niihau is to plan on being without power for longer than the storm lasts, and to have the things that assume no power already sorted: water at a gallon per person per day, food that needs no cooking, prescriptions filled, phones and battery banks charged, and a way to hear official information that is not a phone with a dead battery.

Four large fires are burning in California on the National Interagency Fire Center's current incident list. Plaskett stands at 29,862 acres and 37 percent contained, Timber at 25,362 acres and 27 percent, S 1 Vya at 9,692 acres and 98 percent, and MP18 at 7,601 acres and 95 percent. Plaskett and Timber are the two with substantial open perimeter. In Nevada, McConnell is at 33,241 acres and 83 percent. In Arizona, Paddy Creek is at 668 acres and 63 percent and Mount Emma at 368 acres and 70 percent.

The national wildfire preparedness level is 4 on a five step scale, set September 4 at 7:30 in the morning Mountain time, according to the National Interagency Fire Center. Its national fire news page, current September 7, counts 65 large fires with 15,855 firefighters and support staff assigned, and 53,233 fires for 8,303,398 acres so far this year.

Hawaii carries a federal disaster declaration, number 4936, issued September 1 for an earthquake, and an emergency declaration, number 3652, issued August 25 for Hurricane Lala. Nevada carries an emergency declaration and a fire management assistance grant for the Hawk fire. Households in the named areas can look up the assistance categories under those numbers.

No earthquakes of magnitude 4 or larger occurred in California, Nevada, Arizona, or Hawaii in the past week, according to the United States Geological Survey event feed queried at 5:09 this morning Eastern time.

For Hawaii, the health item that follows a hurricane is carbon monoxide, and it is worth reading in full because it kills people after the storm rather than during it.

Operate portable generators outdoors only, at least 20 feet from homes and buildings, with exhaust directed away from windows, doors, and vents. Install working carbon monoxide alarms on every level of the home and outside sleeping areas, and test them monthly. If a carbon monoxide alarm sounds, get outside immediately, then call 911. That guidance is from the Consumer Product Safety Commission.

Carbon monoxide has no smell and no color. Generator poisoning is one of the more common causes of harm in the days after a storm, when the power is still out and the generator has been running for a while and someone moves it closer to the house because of the rain. Twenty feet is further than it feels. A garage with the door open is not outdoors.

The second health item for Hawaii is the water. Flash flooding and mudslides put runoff into systems that are normally clean. If a boil water notice is issued for your area after this passes, it will come from your county water department rather than from the National Weather Service. No such notices were identified across the region as of this morning.

On the mainland, the health item is heat and it stacks with air quality. An air quality alert is active for all of Imperial County in California from the Imperial County Air Pollution Control District for harmful levels of particle pollution from windblown dust. Blowing dust and 110 degree afternoons affect the same people: anyone with asthma or another lung condition, outdoor workers, older adults, and children.

In desert heat with overnight lows in the 80s and 90s, the body does not get its recovery hours. That is what makes a multi day heat episode more dangerous on its third day than its first. One cool room to sleep in is worth more than a cooler house during the day.

The Centers for Disease Control and Prevention Health Alert Network archive could not be read this run, so this brief makes no claim about national health advisories in either direction.

The next twelve hours are the ones that matter for Kauai and Niihau, and then the situation improves.

Lowell's core is forecast to pass near or just west of Niihau overnight and into this morning, then turn northwest and slow down by early tomorrow. That means the worst of it for Kauai arrives and departs inside a single overnight window, with the rain and the surf outlasting the wind.

The rainfall is the hazard that continues after the wind eases. Up to 24 inches on Kauai on steep island terrain moves fast and it moves debris with it. Roads wash out, culverts back up, and the low crossing that is fine in ordinary rain is the one that fails. Do not drive into water across a road, per the National Weather Service's Turn Around, Don't Drown guidance. The flood watch runs through this afternoon Hawaii time and covers all the main islands, not only Kauai.

For Oahu, Maui County, and the Big Island, this is a strong weather day rather than a hurricane day: tropical storm conditions on Oahu, several inches of rain with isolated higher totals, and high surf. Surf is the hazard that reaches people who are otherwise unaffected, because the beach looks like an ordinary September beach until it is not. Stay off south and west facing shores until the high surf warning expires this evening.

After Lowell passes, the eastern Pacific is not finished. The National Hurricane Center's outlook, issued at 5:00 yesterday afternoon Pacific time, gives a broad area of low pressure several hundred miles southwest of southwestern Mexico a 10 percent chance of forming in 48 hours and a 60 percent chance over seven days as it moves west-northwest. That is a system to check on rather than to plan around, and Hawaii is a week away from any of it if it develops at all.

Tropical Storm Marie remains well offshore, centered near 25.1 north and 125.9 west as of 8:00 last evening Pacific time with 45 mile an hour winds, moving west-northwest at 8 miles an hour and weakening. Marie is not forecast to bring wind or rain to the mainland.

On the mainland the watch item is the heat, which builds tomorrow and holds through Friday across the California and Arizona deserts. The Weather Prediction Center's extended discussion, issued at 1:41 yesterday afternoon Eastern time, expects above normal heat to build briefly across the Southwest and parts of California mid week as upper level ridging extends into the region, alongside continuing monsoonal showers and thunderstorms in the Four Corners.

For the California fires, Plaskett at 37 percent and Timber at 27 percent are both fires with more open edge than held edge, and September is the month when offshore wind events begin in California. Nothing in the current outlook points at one this week.