February 25, 2017 – Flooding concerns continue as runoff from the recent rain continues to work its way downstream adding stress to waterways. A couple of weak but cold storms move through Saturday and Monday. Extended period of dry weather starts by the middle of next week.
Low pressure system along the coast will move southward during the day and may bring a few stray showers to the interior valley today. The mountains will see a few more showers but any snowfall accumulations will be light and less than an inch.
The system will move south of the area overnight and precipitation chances will diminish. Skies will become clear and another cold night on tap. Temperatures will lower into the low to mid 30s by Sunday morning. The coldest temperatures look to be over the north end of the valley.
Closed upper low is currently situated off the California/Oregon coast, with associated frontal system moving through the region. Scattered showers have persisted across the northern portions of our CWA for much of the night, with mainly light precipitation totals reported thus far. Snow levels have been low enough to bring a bit of light snow to roads above 2000 ft or so.
The upper low will continue its path southward today, paralleling the coast. While a few showers will continue mainly over the higher elevations today, dynamics will remain far enough off the coast to keep most of the region dry. By tonight, skies should be clearing again, allowing for another cold night across the region. Some Valley locations (particularly across the north) may reach below freezing temperatures.
A second trough will move into the Pacific Northwest Sunday, bringing another round of showers to the region. Neither this system nor the previous one tap into any meaningful moisture, so precipitation won’t be heavy. However, enough snow could fall over the mountains that Sunday evening travel could be impacted. Snow levels will remain low, mainly between 2000 and 3000 ft across the region.
A few showers will persist into Monday under cyclonic flow aloft. By Tuesday, drier northwest flow will take hold over the region.
Extended discussion (Wednesday through Saturday)
Upper ridging over the west coast will bring dry weather through the extended period. Upper ridge weakens a bit towards the end of next week as a Pacific storm system passes through the Pacific Northwest but any precipitation should remain north of the forecast area. Daytime highs start out around normal on Wednesday then warm through the end of the week especially in the northern Sacramento valley where light north winds and adiabatic warming will push the Redding area up to around 70 degrees. Overall, daytime temperatures at the end of next week should be up to between 5 and 10 degrees above normal.