September 2016 Weather and Climate Summary and Forecast

With school and football season starting a hint of fall is right on time and the transition has started (see forecast periods). But first let’s look back at August… the month lived up to the forecast in some ways but differed in others. Temperatures were mixed with inland California, western Nevada, Oregon and Washington all seeing above normal conditions (2 – 4°F) which was spot on with the forecast (Figure 1) while eastern Washington and Oregon along with much of Idaho experienced near normal temperatures during the month. On the other hand, central coastal California experienced a fairly strong marine layer and fog, resulting in temperatures 1 – 2°F below normal, while much of the Great Basin and Rockies were cooler than normal due to monsoon cloud cover during the month (missed in the forecast). In terms of precipitation, the bulk of the western US was much drier than normal during August (Figure 1), however remember it does not take much to be drier than normal during this month. Nationwide, the dry conditions in the west gave way to much wetter than average conditions from Texas and the Gulf Coast up the Mississippi and Ohio river valleys and into the upper Midwest and Great Lakes while the eastern seaboard was close to normal rainfall (not shown). The nationwide temperature pattern in August was a west, central, east pattern with a generally warm west coast, cool Rockies to the plains and then a very warm eastern third of the country from the Mississippi River to the southeast and into New England (not shown).