7am Sunday Unfortunately, the forecast is on track. Heavy to, in spots, torrential rain is falling in southeast California and parts of Arizona. Flash flood watches and warnings are in effect. Please check with your local trusted source of weather information in order to make sure you have the latest information for your home or business. Again, I strongly discourage travel today and tomorrow.  5:15pm Saturday This is a terribly serious situation as the crest will be very close to the record stage! Many more evacuation orders will be issued. It is vital to have a "go kit." Scroll down to the link to show you what to gather.  12:15p: After I prepared the forecast below, an updated rainfall amount forecast for Arizona came in. More than 8" of rain is forecast to fall in there next three days!  This may cause catastrophic flooding in a few spots with widespread serious flooding. Please see preparedness recommendations below.  -- original post -- This is the flash flood ...

This is one of the wettest rainfall amount forecasts for the central United States that I have seen in 50+ years of looking at this. That is a forecast of more than 7 inches of rain along I-35 from Madill, OK to the DFW Metroplex! There are multiple areas where more than 4" inches of rain is forecast to fall. Please pay attention to the forecasts this week!   Updated flash flood forecasts. The first is from 7pm this evening to 7pm Monday. The red area has a serious risk of flash flooding.  The serious risk moves east from 7pm Monday to 7pm Tuesday. It is vital  that travelers and residents monitor the weather in these areas, including those on Interstate highways that some unfortunately believe "never flood." Make sure you have a "Go Kit" ready if you live in a flood prone or low-lying area. 

Monday 4am to Tuesday 4am The yellow area has a moderate risk of flash flooding while the red area has a higher risk. This includes Interstate 80 between Sacramento and Reno.  Tuesday 4am to Wednesday 4am Yellow indicates a moderate risk of flash flooding as the rain threat shifts south.  Wednesday 4am to Thursdays (Christmas) 4am We have a high risk of flash flooding over much of Southern California as heavy to near record rains are forecast to fall. It is unfortunate that "go kits" will be necessary for the Christmas holiday if you live in the red area.  Of course, I'll have additional updates tomorrow. 

6:15pm. All of the information below still looks valid, so I'm going to leave it up for the night.  I have a busy morning tomorrow, but hope to have something up by late morning, California time. Please check back.  Below are the forecast snow amounts in the Sierra from now until 4pm Sunday.  As much as 40 inches are forecast to fall. Most of the storm will fall on Sunday and the heavy snow will continue Tuesday and, possibly, Wednesday.  The flash flood threat will be high Sunday. ...and, Monday.  Please scroll down to see preparation suggestions.  [10:35am PST Update] New data indicates thunderstorms are nearly certain with storm #2 over parts of Los Angeles, Ventura and Santa Barbara counties. The updated rainfall amount forecast is calling for more than ten inches in the higher elevations of Santa Barbara county and right at ten inches in Los Angeles county!   I cannot overemphasize the importance of pre-planning. Create a "go kit" where you have ...