INTERAGENCY FIRE WEATHER CENTER – PREDICTIVE SERVICES UNIT

 

THURSDAY, AUGUST 25, 2016

SOUTHERN CALIFORNIA GEOGRAPHICAL AREA COORDINATION CENTER

RIVERSIDE, CALIFORNIA

***Breezy in and near the desert through Saturday***

***Warmer and drier for the first half of next week***

A trough will linger over the area the next few days which will maintain moderate onshore flow.  This will result in breezy conditions in the desert interface regions during the afternoon hours.  Expect west to southwest winds of 15-25 mph with gusts to 40 mph across the Antelope Valley and Banning Pass and nearby areas such as the Kern County Mountains and “Canyon Country” of northern Los Angeles County through Saturday.  The onshore flow will result in widespread and deep marine layer coverage which will likely bring higher humidity portions of the Chimney, Sobranes and Rey fires each night.   Temperatures will be near to perhaps a few degrees below normal through Saturday with highs in the 70s along the coast to the upper 80s to lower 90s in the valleys to 105 in the deserts.  RH recovery above and inland from the marine layer will be in the 15-20% over most areas each afternoon.  Early next week, an expansive area of high pressure over the Southwest will back into Southern California, bringing much warmer and drier weather.  Temperatures Sunday will surge upwards 5-10 degrees, and by Monday and Tuesday, the valleys and lower foothills will likely reach the 100-105 range.  Minimum RH will drop into the single digits over most areas below 6,000 feet away from the coast.  The hottest days appear to be Monday and Tuesday before another trough brings cooler and windier weather back to the region by the middle of next week.  No thunderstorms are expected through the period. 

 

Large fire potential will remain low overall through Saturday due to relatively cool and humid weather.  The highest likelihood of a new large fire the next 3 days will be in upland areas surrounding the Antelope Valley where gusty winds will occur each afternoon.  Next week, much hotter and drier weather will send fuel temperatures to very high levels during the afternoon hours.  Minimum RH will be quite low for 6-8 hours each afternoon with fair to poor recovery at night.  Although winds will be light, rapid rates of spread in continuous fuels with near total consumption can be expected.  Large fire potential will remain elevated during the second half of next week due to a return of breezy weather.  A similar weather scenario occurred last week when hot temperatures were followed by gusty winds.  Rapid growth of several of the ongoing large fires occurred last Wednesday through Friday even though temperatures were cooler and RH was higher.  Large fire potential will be elevated all of next week due to the hot and dry weather which will be followed by gusty winds.  Expect moderate to heavy IA and resource demand starting next Monday.   

 

For addition fuels and weather information, including the Santa Ana Wildfire Threat Index, please visit:

 

http://gacc.nifc.gov/oscc/predictive/weather/index.htm