By Jim Purpura. Posted October 2, 2011, 11:04 AM.

The first significant storm system is heading toward southern California. The next weather maker is a developing system that will move down the coast beginning Tuesday and give us a first taste of real fall weather.

The first weather system will move through the area and bring a slight chance of rain and windy, cooler conditions. Late Wednesday into Thursday, a second, much stronger weather system will a period of rainfall, which may be locally heavy at times. Beginning Wednesday, it will be windy, especially in the mountains and deserts. Temperatures will fall dramatically, from the upper 80's/low 90's today, to highs in the 60's to low 70's on Wednesday and Thursday.

Rainfall amounts do not appear to be large, but will be the first widespread rain in many areas since March. Best forecasts are .25 to .50 inch in the Inland Empire to 1 to 2 inch totals on the southwest slopes of the San Gorgonio Mountains in San Bernardino County.

The first snow of the year could appear in the mountains of Riverside and San Bernardino, and LA Counties above 7000 feet, with a few inches of snow possible at that altitude.

The storm systems exits the area after Thursday... with Friday and Saturday forecast to be sunny and quite a bit warmer.

There is still some uncertainty on the timing...track...and intensity of the storms...so check back with weathercurrents.com for updates.

Jim Purpura

Meteorologist

Weathercurrents.com

jpurpura@weathercurrents.com