By John C. Toman. Posted January 23, 2012, 7:26 AM.

Seasonal rainfall totals have languished in the past couple of months in Southern California's inland valleys, and the most recent storm, due Monday, won't make much of a dent in that deficit.

Forecasts are currently calling for a quarter to a half of an inch of rainfall, along with some gusty winds, between Monday morning and evening, as the latest front races through the region.

Following the storm, conditions will revert to warm and dry for the rest of the week, as the jet stream returns its attention northward, and high pressure gets re-established in the south.

The rain season had a promising start, with some rainfall in October, then a wet November. La Nina apparently began to take its toll in December, though, which ended up warmer and drier than normal. That's a trend that's continued into January, interrupted only by a couple of light to moderate storms.

Normal rainfall for January is between 1.5-3" in the inland valleys. With some luck, the wettest areas will total more than an inch after Monday's storm.

For the season to date, which began July 1st, 2011, the current rain deficit (versus normal season to date rainfall) is between 3 and 5 inches.

La Nina conditions in the equatorial Pacific are strongly correlated with dry rain seasons in Southern California, and fewer than normal number of weather system. Last winter season (2010-2011) did see fewer weather systems than normal. But, a mega-storm in December 2010, with seven days of heavy rain, produced 10-20 inch totals, putting the seasonal total well above normal.

February is normally the wettest month of the year in Southern California (with an average of between 2-4" of rain inland), so there's still some hope of catching up to normal for the 2011-2012 rain season.