Very interesting (and scary!) weather forcast for today and Thursday for So. Cal.:

THE HUGE PARENT 507DM GULF OF ALASKA UPPER LOW WILL CONTINUE TO SPIN AND THE SECOND IMPULSE OF THIS WED/THU STORM WILL APPROACH THE AREA THURSDAY MORNING. THIS IS ONE OF THE MOST INTERESTING LOOKING STORMS OF THE LAST 20 YEARS. AT 700 AM A TRIPLE SURFACE LOW STRUCTURE WSW OF POINT CONCEPTION APPROACHES THE AREA AND THEN CONSOLIDATES INTO A DOUBLE LOW STRUCTURE AND SWEEPS OVER THE AREA. AT THIS TIME THE MDLS ARE SHOWING AN EXTRAORDINARILY VIGOROUS WEATHER SITUATION OVER THE ENTIRE AREA LATE IN THE MORNING AND EARLY IN THE AFTERNOON AS MAXIMUM CYCLONIC JET DYNAMICS INTERACT WITH A POWERFUL SURFACE FRONT. AT THIS TIME THERE WILL BE STRONG THUNDERSTORMS...HEAVY RAIN...POWERFUL WIND GUSTS...AND MOUNTAIN SNOW DOWN TO 5000 FEET. AS THE THE SURFACE LOW CONSOLIDATES AND DEEPENS IT WILL SLOW EVERYTHING DOWN AND THE STORMY WEATHER WILL CONTINUE FOR A LONGER PERIOD THAN IT HAS FOR THE PAST FEW DAYS. AGAIN MAX RAINFALL RATES OF 1.5 INCHES PER HOUR AND RAINFALL AMOUNTS OF 1-2 INCHES OF RAIN WITH THE MTNS SEEING 2-4 LOCALLY 5 INCHES THROUGH THIS EVENING ARE LIKELY WITH THIS SECOND IMPULSE AND IF THE WRF FORECAST IS CORRECT BOTH THESE VALUES WILL HAVE TO BE RAISED UPWARDS.

Weather like this happens about once every ten years here in L.A.