AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 241 PM PST Fri Mar 6 2015
.Synopsis... Warm daytime temperatures will continue into early next week under ridge of high pressure over the western U.S. Daytime highs over the weekend will be around 10 to 20 degrees above normal with nighttime low temperatures around normal. High temperatures returning to closer to normal by the middle of next week with possible return of precipitation, mainly over the mountains, starting Wednesday.
.Discussion... Warm and sunny day today with temperatures generally in the 70s in the Valley and mid 50s to 60s in the mountains this afternoon. These temperatures are several degrees warmer than yesterday with increased subsidence and warming airmass. The most warming is in the Northern Sacramento Valley with northerly downslope winds bringing some additional adiabatic warming for about 12 degrees warmer than yesterday afternoon. The mountains have also seen a jump in temperatures around 10 degrees compared to yesterday. Temperatures are expected to be similar to a little warmer over the weekend and Monday with persistent high pressure. Redding Airport has reached 81 degrees so far today which breaks the old record of 80 degrees from 2005 for the airport. Near record to record temperatures for this weekend with records mainly in the low 80s in the Valley which were mostly set in 2004, the Northern Sacramento Valley has the best chance at breaking records this weekend too. The record for March 7- Redding Airport 83 in 2004, Red Bluff 82 in 2004, Downtown Sacramento and Sac Exec 81 in 1953 and Stockton 82 in 1953, for March 8 Redding Airport 84 in 2004 and Red Bluff 83 in 2004, Downtown Sacramento 80 in 2004, Sac Exec 78 2004 and Stockton 82 in 1953. for March 9- Redding Airport 85 in 2004, Red Bluff 87 in 1934, Downtown Sacramento 81 in 2004, sacramento Exec and Stockton 77 in 2004. Low temperatures will be around normal with temperatures generally in the upper 30s to 40s except mid 20s to 30s in colder mountain valleys and over highest elevations. Winds will generally be light north to east with weak pressure gradients over the area.
.Extended Discussion (Tuesday through Friday)
For the extended forecast, Tuesday will be mostly dry as ridging lingers above NorCal before exiting eastward. A slight chance of rain could move into far NorCal Tuesday night including parts of Shasta, Tehama & Plumas Counties as a low pressure system moves into the West Coast. Models are still varied in the details of this event with the GFS just clipping our northern CWA and then quickly exiting by Thursday morning. The GEM and ECMWF show a slower moving system that tracks farther southward into our region that persists into Thursday. Have kept a slight chance to chance of precipitation on Wednesday into Thursday, then dissipating by Thursday evening. By Friday, ridging returns to the West Coast with a return of warmer and dry weather. JBB
Strong high pressure over Norcal resulting in VFR SKC conditions with light winds through Sat.