Ramblings of a Graduate Student

Over the past week, a series of storm systems have walloped the west coast of the United States with wind, rain, and even a rare southern California tornado!  So much rain has fallen in such a short amount of time, mudslides are becoming a worry.  Today’s set of  images attempts to put into context just how much rain has fallen in southern California in terms of the last six months rainfall total.  Please note that today’s rain is *not* included in these totals!

Also, continuing with the tornado watch theme from yesterday, a rare tornado watch for southeastern California and southern Arizona was issued by the Storm Prediction Center earlier today.  This is the eighth tornado watch this year (also the eighth tornado watch issued in the last 36 hours!).

The image above displays the “normal” expected rainfall for 14-21 January.

The image above displays the observed rainfall for 14-21 January of this year.

The image above displays the departure from normal rainfall for 14-21 January 2010 in terms of inches.  Several places have received more than 8 inches more than normal.

The image above displays the departure from normal rainfall for 14-21 January 2010 in terms of percent of “normal”.  Several places have received more than 600 percent of their normal rainfall.

The image above displays the departure from normal rainfall for the past 180 days, ending 21 January in terms of inches.  Even with the heavy rains of the last week, most places in the desert southwest still remain several inches below normal.  Places that are not significantly below normal are typically within 2 inches of normal.  When you consider how much rain has fallen over the past week, one begins to appreciate the drought that was plaguing the southwest.

The image above displays the departure from normal rainfall for the past 180 days, ending 21 January in terms of percent of normal.  Even though a lot of places are within 2 inches of normal, they have received only about half to maybe three-quarters of their normal rainfall.  This goes to show just how little rain the southwest receives – they can be within two inches of normal and still only have 50% of what they would expect.

Also, not everywhere in the last two images have below average rainfall over the last 180 days.  Places along the coasts and in the higher elevations of California are above normal – however, a significant portion of that has fallen this week!

And last, but not least, the outline and (color-filled) counties included in the desert southwest tornado watch!

The much advertised rains have begun to pummel southern California.  Radar estimates (which tend to be low because of the many mountains and high bluffs) of over 7 inches of rain are already showing up southeast of Santa Barbara in Ventura county.  Remember the big “Station Fire” from 2009?  Several mudslides have already been reported in the charred areas left over from the fire.  You can check out more news results regarding the  southern California storm along with discussions about its impact on the areas impacted by the Station Fire here.  This is just day 1 of a prolonged rain event and several residents have already been asked to evacuate.