Saturday, July 4, 2015
Similar to the last few days, there will be a chance of afternoon storms today, though with increasing atmospheric moisture there is a greater chance of wetting rains. As discussed in last week’s forecast, a strong cold front for the summer season is forecast to cross the area around sunset Sunday. Coincidentally, a weak wave from the southwest is forecast to cross over our area around that time or even as early as noon. The end result is showers should increase through the day as temperatures drop, especially later in the day, with some storms producing periods of heavy rain. Showers should continue overnight and into Monday morning.
The cold front will keep temperatures quite cool on Monday with continued showers. Again, some of these showers could produce locally heavy rainfall, though the cool air will moderate the strength of these storms.
Moisture will remain over our area for the following workweek, allowing for the possibility of storms each day though Friday that may produce continued locally heavy rainfall. Storms on Tuesday may be enhanced by another much weaker cold front moving though the area that day.
The forecast pattern is monsoonal-like, though the northward moisture transport in this case is not solely caused by the usual mechanism of upper level flow rotating around the eastern side of a strong western ridge. Instead, waves of energy moving over our area, including the cold fronts on Sunday and Tuesday, appear to be the primary driver of our wetter pattern.
Dry air is currently forecast to return to the area for next weekend as a storm from northern California drags dry air over our area as it passes to our north. This looks to end our wet week as a dry ridge is then forecast to build over the west, bringing a return to hot and dry weather.