Tucson Monsoon Weather – drying up and Cooling Down – 9/23/2018

Looking at the last month of data, we could be seeing a trend towards drying up and cooling down.  The length of the days  is getting shorter and the light is less intense (see the Light spectrum ‘bumps’).  Also, the temperature swing is smaller through the day.  The pressure went up quickly after the last rain event and now is tapering off.  We’d expect higher temperatures for the last couple of days but didn’t see that.  The daily lows seems to be a bit lower each day.  Barring unforeseen weather events, I think we’ll start seeing the range between the highs and lows get smaller each day.


Tucson Monsoon Weather – Rain Event – 9/21/2018

Here’s an example of what rain looks like.  We had a good solid day of rain a couple of days ago and you can see it clearly on the chart.  When the green Humidity line intersects the magenta temperature line, that is a really strong indicator of actual precipitation.  Note that the Luminescence plots are much smaller and shorter in the time dimension for the rain day too.  This indicates that the light was low and the day was shorter due to clouds.

Of course, we see the dry trends returning.  Pressure is rising and humidity seems to be falling now.


Tucson Monsoon Weather – Is the Monsoon Returning? – 9/18/2018

In the first chart below you can see the last full month of data.  There was quite a spike in humidity and lightning earlier in the month, but unfortunately it dried up.  The daily humidity oscillation amplitude have decreased and the temperatures have increased slightly since that round of storms.

However… looking at the second chart, which focuses on the last week of data, we can see the humidity numbers increasing.  The sensor has been detecting small lightning events (they may/may not be real, but we have had cloud cover at times).  Are we going to have a return of the monsoon?


Tucson Monsoon Weather – 9/4/2018

Lots of weather over the last couple of days!  You can see the buildup of the cloud cover, as sampled by the light spectrum measurements starting on 8/31.  Humidity gradually increased over that period and pressure dipped slightly.  The intersection of the humidity line and the temperature line on 9/2 is a typical indicator of rain.  In this case, the rain lasted for around five hours or so.  Lots of lightning captured and some of it quite close!  All cleared up on 9/3 and we see the humidity drop quickly during the day.