Tucsonβs below average rainfall for August, which is typically the wettest month during monsoon season, might mean itβs time to face the music and prepare for a potential short-term drought, according to local weather experts.
As of Aug. 30, Tucson saw just over 1Β½ inches of rain during the month, falling 0.80 of an inch below normal. There was a slight chance of rain forecast for Saturday, which could bring up the monthβs total. Rain remains in the forecast for most of the week.
βThe main reason is that the monsoon ridge that kind of helps bring in moisture hasnβt been in a favorable position for a lot of August, so weβve had a downtick in storm activity this month,β said National Weather Service meteorologist Aaron Hardin.
An average Tucson monsoon, which runs from mid-June through Sept. 30, brings about 6 inches of rain. With only one month left, Tucson has just over 2.6 inches of rain. The Climate Prediction Center is forecasting normal rain through September β 1.29 inches β so itβs unlikely the last month of monsoon will be enough to catch up to a normal season. If the monsoon ended today, it would be the 21st driest on record for Tucson, according to the weather service.
βIf the recent past is any indication of the future, we donβt have a ton of hope,β said University of Arizona climatologist Mike Crimmins. βWeβre really late in the season for any major catch-ups. I think the chance of us going above average at this point would really require an exceptionally wet September, and I think thatβs unlikely. Reaching average is also going to be really tough to do and it would require some pretty heavy rain and fairly frequently going forward.β
Even with unlikely chances of heavy rain, in September Crimmins said the East Pacific tropical storm season just began to pick up within the last week or so, which could potentially have an impact on the storms we see in Tucson.
After experiencing above-average showers for winter and spring earlier in the year, weather experts are still unsure what this yearβs winter will look like in terms of rainfall.
βLast year was exceptionally wet in the later part of winter from January and especially February,β Crimmins said. βItβs not super clear why that was the case because El NiΓ±o was kind of weak. We currently donβt have an El NiΓ±o on deck for the upcoming winter. The forecast is showing kind of neutral conditions for El NiΓ±o, so that doesnβt give us a lot of insight into what the winter might have in store for us. So, weβre kind of in that wait-and-see window.β
According to Crimmins, local climatologists have been in contact with the United States Drought Monitor based on data showing abnormally dry conditions for most of the state.
βNot seeing precipitation at the right time during the summer has impacts on ecosystems and agriculture, so we do have short-term drought creeping back into the state,β he said. βLast winter was really, really helpful and erased a lot of that short-term drought, but itβs pretty easy for us to slip back into that. So, given one wet winter and a crummy summer, that doesnβt leave us in a great spot and could cause things to deteriorate pretty quickly.β
A dry winter could cause Tucson to slip back into short-term drought conditions, lasting up to six months. As a state, Arizona is still facing a multi-decade, long-term drought from many years of below average precipitation, which continues to impact the stateβs water resources.
