Despite this morning's soggy San Francisco beginning to the month of March, the historic odds of even getting close to normal are near zero; even with an above normal March AND April.
After late evening rain on February 28th, San Francisco doubled their monthly total from 0.21" to 0.42". This pushed them down (up?) to the 16th driest out of 169 years in SF February rainfall records. It also pushed the 8-month total for the rainfall season to date (i.e., July 1 to Feb. 28) to 9.03", the 17th lowest on record.
A look at San Francisco's rainfall seasons following such a dry first eight months shows that it has never recovered, even with substantial March and April rains, to even close to normal. Of all the years that saw less than 11 inches of rain in this period, only one (1898-99) made it to 71% of normal by the end of the season with 16.87".
For seasons with only between 8" and 10" of rain on March 1st, the average March-April totals have been just 3.08", or 65% of normal for the two-month period.
Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Phone: (408) 379-7500