Today: Nov 18 , 2019

Lovely Weather This Week!

03 June 2019   Dr. Mark Sinclair

Sunny weather this week, with a few light breezes.

Weather Discussion:

Yet another weak upper low that has been to our west for several days, will move across Arizona Tuesday and Wednesday, bringing a chance of showers and isolated thunderstorms Tuesday evening. Typical (boring for the weather nuts) early summer conditions will finally arrive later in the week and into the weekend, with afternoon breezes each day.

Additional notes for the weather nuts out there:

As you may have noticed, May was anomalously wet. The Flagstaff NWS is featuring a precipitation table for May that shows that Prescott recorded its wettest May on record, with 3.42 inches, against an average of 0.42 inches. Here at the University, we recorded 1.75 inches (see

The latest sea surface temperature (SST) anomaly map (attached) show regions where the sea is warmer (yellows and reds) and cooler (blues) than normal. Notice the cooler than normal SSTs in the Gulf of California. 

This is where most of our moisture originates during the summer monsoon. If this cooler water persists, we can expect a later start to our summer monsoon precipitation, because warmer water results in more abundant moisture. The ongoing El Nino, seen in the SST anomaly map as the warm water in the tropical east Pacific, is also known to delay the start of the monsoon. The good news (for those that love precipitation – since you are reading this, you must be a weather nut, right?) is that the warmer water southwest of California might support more hurricane activity later in the summer and fall (August-October), so the monsoon might start with a whimper but end with a bang!

Another factor that may contribute to a slow start to our monsoon precipitation is residual late season snowpack and the moist state of the ground. Monsoon precipitation typically commences when the mid-level high pressure moves to a position north of us, optimally to a location near the four-corners. To build an upper high pressure system, we need strong solar heating. This heating is reduced when some of the sun’s energy is used in melting high elevation snow and evaporating moisture rather than warming the atmosphere. 

Have a wonderful week,


Met Mail is an unofficial weather discussion and forecast transmitted once or twice a week via e-mail by the Embry-Riddle Department of Meteorology ( This has a selection of model forecast products and other links. Embry-Riddle offers an undergraduate bachelor-of-science degree program in Applied Meteorology. Please spread the word to all potential qualified candidates!

Further Information:

ERAU Applied Meteorology degree program

Official National Weather Service forecast

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