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California’s Oak Fire Near Yosemite Spreads Rapidly

July 28, 2022

The Oak Fire, burning near California’s Yosemite National Park, exploded in size the weekend of July 23–24, 2022 after igniting on Friday, July 22, and is now the largest fire in California so far this year. According to fire officials, the flames are moving extremely fast through the parched foothills of the Sierra Nevada mountains fueled by a large amount of dried vegetation, a result of extended drought conditions. 

The fire has currently consumed more than 18,800 acres and has destroyed 100 structures. So far, more than 6,000 residents have been evacuated. California’s governor, Gavin Newsom, declared a State of Emergency for Mariposa County on Saturday, and air quality advisories were issued in the Bay Area due to heavy smoke. 

The fire is also affecting other states. The National Weather Service in Portland, Oregon, said that high temperatures may be impacted or lowered if the smoke from the Oak Fire reaches the area. 

According to CalFire, more than 3,700 personnel, 303 fire engines, and 24 helicopters and more are battling the blaze. The cause of this fire is still under investigation, and crews now have it 36% contained as of July 27.   

Cal Fire acknowledges the state's longer wildfire seasons, which experts say are beginning to stretch throughout the year, are the direct result of climate change.

NOAA satellites are providing critical data on the wildfires. The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on the Joint Polar Satellite System’s NOAA-20 and Suomi NPP satellites plays an important role in detecting and tracking wildfires, especially in remote regions. The high spatial resolution from VIIRS allows the instrument to detect smaller and lower-temperature fires. VIIRS also provides nighttime fire detection capabilities through its Day-Night Band, which can measure low-intensity visible light emitted by small and fledgling fires.

NOAA’s geostationary satellites provide timely and potentially life-saving information in a dynamic fire environment. GOES-16 and GOES-17 frequently detect fires before they are spotted on the ground, which is particularly important in remote areas. These satellites not only see the smoke generated by these fires but also use their infrared imaging capabilities to show where the hot spots from these fires are in real-time, pinpointing where and how intense a fire is. They also alert us to the presence of dangerous pyrocumulonimbus clouds and monitor ensuing severe weather conditions.

The High-Resolution Rapid Refresh (HRRR)-Smoke model produces forecasts of both surface and high-altitude smoke up to 48 hours into the future. The model, which is used by fire crews, first responders and air traffic controllers, builds on the existing High-Resolution Rapid Refresh weather model, which forecasts rain, wind and thunderstorms. It ingests real-time data captured by the JPSS satellites’ VIIRS instrument on the amount   of heat released by the fire and combines that with vegetation maps to incorporate what’s burning. (Sage burns differently from Ponderosa Pine, for example.) All of these measurements are mapped to a three-dimensional grid that extends nearly 12.5 miles into the atmosphere, producing detailed updates of the amount of smoke produced, the plume height and the direction the smoke is expected to move.

The benefits provided by the latest generation of NOAA satellites aren’t just seen during a fire but are important in monitoring the entire life cycle of a fire disaster. Data from the satellites are helping forecasters monitor drought conditions, locate hot spots, detect changes in a fire’s behavior, predict a fire’s motion, monitor smoke and air quality, and monitor the post-fire landscape like never before.