After a vividly unforgettable and record-breaking wildfire season last year, all of the conditions are in place to ferment an elevated fire risk across the Southwest over the weekend and even into next week.
Residents are gearing up for yet another bad fire season. Unfortunately, the puzzle pieces are all already in place, from heat to high winds to dryness, causing widespread red-flag warnings to go into effect sooner rather than later.
— NWS Storm Prediction Center (@NWSSPC) May 8, 2021
The Storm Prediction Center has labeled two “critical” fire risk areas on Saturday inside of larger “elevated” fire risk areas in the Southwest.
“With persistent dryness, low humidity and breezy conditions, the risk for wildfire start and spread will be elevated across parts of the West this weekend,” said AccuWeather meteorologist Mary Gilbert.
One important element involved in wildfire risk is the moisture in the air, or lack thereof. In several cities across the Southwest, humidity has been dropping dangerously low. On Friday, Phoenix and Las Vegas both reported relative humidity levels below 10, and forecasters believe humidity levels will continue to decrease over the weekend.
“Humidity levels will be so low that some locations could experience amounts as extreme as less than five percent,” Gilbert said.
Not only is the air itself dry, but rain has also held back in this region for several months. Areas under stress of drought feature dry vegetation that can catch fire much easier than hydrated plants.
— NWS Hanford (@NWSHanford) May 6, 2021
“The entirety of California’s San Joaquin Valley is in the midst of extreme drought, according to the U.S. Drought Monitor,” Gilbert said.
Fresno, Calif., has received less than 2 inches of rainfall since the beginning of February, which is only 34 of its normal precipitation in that time. Modesto, Calif., has also only received 30 of normal rainfall since early February. Over 70 of the entire state of California is considered to be in extreme drought.
Albuquerque, N.M., totals about an inch of rain since Feb. 1, which would put it just above 50 of normal precipitation. Phoenix has recorded even less than an inch since then, with 17 of normal rainfall.
“The more severe the level of drought, the more likely any fuels like grass or shrubs are to behave like kindling in a fire situation,” Gilbert said.
Heat is also expected to exacerbate the drought across the West this weekend. Phoenix’s temperatures have been above average since Tuesday, and the city hit its first 100 F temperature of the year on Wednesday, then hit it again on Thursday. High temperatures there are not forecast to fall below average for at least a week, though another 100 is not expected.
The weekend will be warm in the Southwest, but not outrageously so, and temperatures will likely hover just above normal.
Dry and warm conditions can cause wildfires to start, but it will be the breezy conditions that accentuate and spread the flames.
“The cold front that will cross the Western states over the weekend will touch off strong winds,” said AccuWeather senior meteorologist and lead long-range forecaster Paul Pastelok.
Winds in cities like Flagstaff, Ariz., and Albuquerque are expected to blow at 10-20 mph on Saturday. Sacramento can even have winds of 15-25 mph.
Strong north winds that began to sweep across Northern California, Nevada, Utah, Arizona and New Mexico on Friday will continue on Saturday, raising the fire threat, according to Pastelok.
Red flag warnings suggest the strongest winds for Northern California will be along the west side of the Sacramento Valley and through canyons and gaps. In Southern California, including the Kern County Mountain and desert areas, can have gusts up to 55 mph.
Some of the gustier areas of the Albuquerque region will include the Central Highlands, Estancia Valley and Curry County, with gusts up to 50 mph possible.
As the weekend ends, dry conditions and high winds are expected to continue, while heat starts to build excessively in the Southwest.
“With a bulk of the moisture at the middle and upper levels of the atmosphere forecast to remain removed from the Desert Southwest, dry conditions will be the norm for the region into at least early this upcoming week,” Gilbert said.
“Strong winds are likely to continue across New Mexico and Arizona Sunday and Monday, where the fire danger will remain very high,” Pastelok said.
As a storm system moves away from Colorado and Wyoming early next week, a dome of high pressure will build across the West,” Pastelok said. This will send temperatures soaring.
Phoenix will get another chance to hit 100 again on Wednesday, as it is forecast to reach 99 F. Albuquerque can also head into the 80s toward the end of next week.
“It will be back in the 90s in the Central Valley of California Tuesday through Friday of next week, some places may reach 100,” Pastelok said.
More 100-degree Fahrenheit heat is likely in the deserts.
“Temperatures will also be several degrees above normal across the interior Northwest and most of the Rockies later in the week,” added Pastelok.