All Weather News

Rain, Rain, Please Come Today!

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Much of the Golden State has been dealing with harsh drought conditions for the past few years.  In some places, the drought has been something the likes of which almost all haven’t seen in a lifetime.  In towards the San Francisco area, that has also been the case, and they just saw something they have never seen before, a January with any rain. 

From October through March, California goes through its rainy season, where it sees it’s annual rainfall predominately come through those months.  So far this Winter season, the typical rains have been few and far in between.  Over in towards the San Francisco area, they typically see on average for January, about 4.33″ of rain, between the city itself and the airport area (the two areas where weather information is recorded for the area).  The past several years, however, we have seen less and less rain come down, where not even a trace of rain was reported in the San Francisco area for January 2015.  

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 Records in the San Francisco area go as far back as 1850, and this is the first time that there has not even been a drop of rain reported for the region for the month of January.  You can see how much rain the area should typically see on average basis.  By the time January 31st rolls around, there should have been over 4″ of rain reported to have fallen for the area, but as time marched on, we didn’t even see the city get a quarter of the amount they should have gotten.

 But, there is some light at the end of this long, dark & dry tunnel.  A storm system is going to be approaching the West Coast as we go through this work week.  The Pacific Northwest will be dealing with the rain and snow showers at first, but that moisture will eventually make it’s way towards California later on.

03_MOISTURE The plume of moisture is coming all the from the central Pacific Ocean, and it will flow into the West Coast through the work week and into the following work week.  

Along the coast will be where the heavier rains will come down.   Due to the mountain influence of the terrain, such as the foothills of the Coastal and Sierra Nevada ranges, we’ll see more shower activity squeezed out.  In the higher elevations, there will be snow coming down.  And the snowpack across much California, could certainly use the snow.  Their snow base has been dismal this Winter season.  

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 The drought’s effect can clearly be seen in these satellite images from NOAA on the left, where there is a lot of brown on the map.  Look at the map on the right, and you can see how much things have improved.  A wet December brought about an increase in vegetation to the Great Central Valley.  But due to warmer temps over the course of January, and with a lack of precipitation, the snow pack has dwindled to a shadow of what it was a year ago.

02_CADroughtThe drought picture has not improved across all of California, when you look back from current conditions, to how things were a year ago.  Every drought category has seen conditions get slightly worse, with the exception of the Exceptional Drought category.  That one has seen its percent of affected area quadrupedal over the course of one year.  The above image is from the Climate Prediction Center 

04_SFOFORECASTWhile the forecast for San Francisco does have rain in it, and several days of it I may add, the accumulated precipitation will only help to put a dent into that drought.  The forecast calls for about 1-2″ of rain to come into the area.  If it comes down in heavy downpours, as supposed to steady showers, we’ll see a good chunk of that rainfall run off, as the ground has to take time to absorb the falling rains.  

 Meteorologist Addison Green

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