April Showers Brought May Flowers…

Three storms brought rain to the Napa Valley last month, but most of the rain fell during the much hyped “atmospheric river” storm on April 5 – 7. 

This storm dropped 2.8 inches in the Napa area, which is 159% of average for the entire month.  Thanks to this storm, it was the sixth wettest April of the past thirty years.  The ALERT System monitoring stations recorded between 2.21 – 5.32 inches valley-wide during the month, approximately 10% of mean annual precipitation.  On average, we receive 7% of our rainfall during April.

This plot shows that WY 2017-18 rainfall totals from the monitoring stations (which ranged from 15.70 – 30.31 inches) are at approximately 63% of mean annual rainfall through April, well below the long-term average of 94% for this time of year.

– Paul Blank, Senior Hydrologist – Paul@NapaRCD.org