Despite more than 50% of June days averaging below normal mean temperature, the mini heatwave towards the end of the month that posted 3 days in the 90s, including a hot day of 99 degrees, was enough to boost the June mean temperature to above normal by 1 degree Fahrenheit for the 30 day period.
The July update shows a similar pattern of a trough off of the northwest coast, which will likely bring a number of cooler than normal days for the month. However, like June, I believe the month will see at least 2 or 3 mini heat waves that could pull the average for the month to slightly above normal.
Here is the July update from the National Weather Service (NWS) showing the cooler than normal pattern in our local region, with an equal chance to see at least some rainfall for the month.
Current weather models show Portland's next threat of 90 degree heat to arrive July 10 or 11, and possibly last 3 days. While some models show little chance of hot weather the mid or later part of the month, the EURO weather model hints at a possible 5-7 day run of extreme heat with possible 100 degree days around July 19-25th.
The map below shows the potential hot weather ridge centering over Nevada and extending north into Canada on July 20th. If true, the heat center would support 100 degree temperatures with an east wind flow in our local region.
The good news is that fire season has indeed started late this year. The only large wildfire reported as of July 3rd is the Willow Creek fire near Ontario. The fire is 85% contained and has burned 40,000 acres of grass and brush. The July outlook of near normal to possibly below normal temps means fire season may not get that active overall until late month or August. I do still believe that August will present this summer's best chance to see hot weather with temp averages above normal. With that said, we may get lucky this year with much of the hot weather holding to our east towards the Rockies.
Rod Hill
