TUCSON - The official start date for Monsoon is still a couple weeks away, however, we have already seen three severe thunderstorms in Southern Arizona.
A warm May, a south wind and higher humidity levels in Southern Arizona contributed to three severe storms that moved into our area on Sunday and Monday.
On Saturday, there was even evidence of a microburst.
According to Ken Drozd of the National Weather Service in Tucson, this is not Monsoon, but just storms caused by normal daytime heating.
"Monsoon is a seasonal shift in the prevailing wind direction," Drozd said. "So for us in southeast Arizona, that means we need to phase out of the west-east air flow in the upper atmosphere to a more east to west flow"
Traditionally, June 15 has been the start of the Monsoon since that is when those winds start to shift, but the worst storms usually aren't seen until July.
News 4 Tucson's Chief Meteorologist Matt Brode has been studying the Arizona Monsoon for years and has seen a number of strong storms and heavy rain in late May.
"Last May, we had record rains through the month of May, that is not technically in the Monsoon," Brode said. "Unfortunately, I don't know if it is due to the rain we had in May, but it really didn't have a good Monsoon subsequently after that."
The nature of these storms makes them hard to predict, so if you are on the roads even if it is not raining that hard, you need to be alert.
The humidity and temperatures are dropping over the next couple of weeks so we should be seeing a quiet start to the monsoon this year.