Thursday, July 31, 2014
The moisture and cool air discussed in the Monday morning forecast verified nicely, and there is a slight chance of afternoon storms today as the main push of monsoonal moisture retreats south. However, the remnants of former hurricane Herman off the coast of Baja will keep some moisture over our area tomorrow, allowing for a greater chance of the typical afternoon storm then.
Most of the weekend is forecast to be considerably drier and warmer, however, the monsoonal pattern is re-energized late Sunday and through much of next week. This occurs as an easterly wave present in the east to west tropical flow over Mexico is entrained into the clockwise flow around the western ridge, moving moisture and upward forcing over our area, similar to what occurred this past Tuesday and Wednesday. Interestingly, this wave is forecast by some models to split into two pieces, with the first piece moving over our area on Monday leading to the threat of more heavy rain.
The second piece is forecast to merge with a separate wave moving into the Pacific northwest and move over our area midweek, again increasing the likelihood of heavy rain that may last until the end of the workweek. Finally, a different and further south Pacific wave is forecast by some models to cross the central west coast sometime around next weekend, with drying and warming expected as the flow veers from the south to the southwest ahead of the wave and drags some warm and dry air over our area.