By Jim Purpura. Posted October 9, 2011, 2:39 PM.

Weak high pressure has given the Inland Empire a quick rebound from the middle of last week, when very cool temperature and widespread rain moved across the Inland Empire and the slopes of the San Jacinto and San Gorgonio Mountains.

High pressure will strengthen significantly beginning Tuesday night, then continue strong through Thursday. Offshore wind flow (that is, east to northeast) will prevail, especially in the mornings and close to the mountains. This will result in rapid warming and drying across the area. High temperatures will be in the 90s and relative humidities will drop to 15% or lower.

Generally this might signal the start of the high fire danger period. However the widespread rainfall will help keep fuel moisture above critical levels across much of the Inland Empire, meaning large fire potential will be in the low to moderate range. Areas across the Inland Empire received 1/2 to 3/4 of an inch of rain. San Bernardino received 1.18 inches on Wednesday, October 5, and Devore, on the southwest slopes of the San Gorgonio Mountains, received in excess of 4.5 inches.

However the Geographic Area Coordination Center (GACC) in Riverside advises " fire activity is expected to increase during this period with the threat of large fires increasing to moderate levels, especially in the urban interface regions of southern California and where only light amounts of rainfall fell."

While the areas adjacent to the San Gorgonio mountains received plentiful rainfall, the foothills of the San Jacinto Mountains were not so lucky. For example, the WeatherCurrents site in Hemet received only 0.22 inches of rain.

Jim Purpura

Meteorologist

Weather Currents

jpurpura@weathercurrents.com