I came across an obituary for a distant cousin which mentions that he was a state climatologist who developed the "55/3 monsoon formula."
KANGIESER, Paul Carl, 1923 – 2003 Passed away September 15, 2003 after a long battle with cancer. Born in Topeka, lived in LA as a child. Served in the U.S. Army for four years in WWII. As state Climatologist of AZ he developed the 55/3 monsoon formula.
I searched Google and couldn't find any formulas related to monsoons known as the "55/3 formula", but I did find this news article:
In 2008, The National Weather Service in Phoenix decided to make a big change. For decades, the monsoon was said to have started after three consecutive days with a dew point of 55 degrees of higher.
What is the 55/3 monsoon formula?