Dr. Greg Jones recently published an updated weather and climate summary and forecast. This report looks back at June and forecasts conditions for July, August, and September.
Summary:
- A cool end to June for much of the western US, but a warmer than average* month overall.
June was mostly dry over the west, with localized wetter than normal conditions in western Washington, northern Nevada, the Plains in Montana, and the Southwest, where monsoon flow has started.
The drought footprint in the western US is now at 91% and is likely to expand in the PNW as the summer dry and warm period sets in, while forecasted monsoon flow is expected to lower drought levels in the Southwest and Great Basin. The first Tropical storm of the year has lowered drought concerns along the Gulf Coast and Southeast, while the mid-Atlantic region is forecast to remain dry this summer.
The current cool conditions over the west will transition to seasonal by the weekend for most, then build to warmer than average by mid-month. Forecast confidence depends on the Pacific high pressure area shifting eastward to its normal position closer to the West Coast.
The July forecast is calling for warm and dry conditions over the western US, especially across the PNW. However, subtropical moisture could bring higher humidity and the threat of thunderstorms throughout much of the Intermountain West.
The seasonal forecast for the western US also continues to call for warm and mostly dry. However, El Niño developments in the Tropical Pacific are expected to increase monsoon flow into the Southwest and possibly across much of the West. Models are pointing to likely more eastern Pacific hurricanes, stronger monsoon flow, increased humidity over the west, and the threat of thunderstorms regionwide.
*Note that all references to normal or averages in this report are to the 1991-2020 climate normal for each weather/climate parameter unless stated otherwise. See this website for more information on climate normals.
View the report (PDF) on the Abacela website.
