Back-to-back atmospheric river storms are set to drench Los Angeles County this week, bringing much-needed moisture to the parched region. However, experts caution that this rainfall may not be enough to definitively end the fire season.
According to meteorologists at the National Weather Service, two "Pineapple Express" storms will sweep through Southern California, with the first peak expected Tuesday night through Wednesday midday, followed by a second system Thursday night into Friday morning.
While the rain is welcome news for the drought-stricken area, it typically takes three to six weeks for native vegetation like chaparral and coastal sage to properly absorb rainfall moisture, explains Todd Hall, a meteorologist with the NWS Oxnard office. This means the immediate fire risk may persist despite the wet weather.
Downtown Los Angeles could receive around four-fifths of an inch of rain through Friday. However, meteorologists indicate that 2 to 4 inches of widespread precipitation would be necessary to confidently declare an end to fire season.
The timing is particularly critical as forecasters predict another round of Santa Ana winds potentially arriving this weekend. These dry, gusty conditions flowing from inland desert areas could increase fire danger, especially if vegetation remains insufficiently saturated.
Southern California continues to face substantial rainfall deficits. Downtown LA has received just seven-tenths of an inch of rain since October 1 - merely 9% of typical averages for this time of year. San Diego logged just 0.35 inches, marking its driest start to a water year since record-keeping began in 1850.
Looking ahead, February traditionally brings the heaviest rainfall to California. However, current forecast models suggest the jet stream may bypass Southern California, instead tracking over the Pacific Northwest before dipping southeast over Nevada and Arizona.
While this week's atmospheric rivers offer some relief, they likely represent just a down payment on the region's substantial moisture debt rather than a definitive end to fire concerns.