November 10, 2018 – Red Flag Warning in effect. Northeast to east winds 15 to 30 mph gusts 35-45 mph in the Foothills, locally higher Sierra ridges & canyons. Strongest winds Placer County northward for Foothills.
Dry weather with above normal temperatures is forecast to continue over NorCal through next week. Another round of gusty winds will be possible this evening into early Monday as a disturbance drops into the Great Basin. However, the winds are not expected to be as strong as Wednesday night and Thursday for the Valley. Critical fire weather conditions will return this evening into Monday morning due to low humidity and gusty winds. Winds will gradually diminish during the day Monday. Areas of smoke will be possible across interior northern CA, especially in the vicinity of the Camp Fire.
Discussion
The area remains on the east side of Pacific ridging, with a dry airmass over the area. Skies are mostly clear of clouds, along with light to near calm winds allowing temperatures to drop. Temperatures were generally already in the upper 30s across the Valley by 3 am. Redding was 35, 24 degrees cooler than the same time yesterday, when there were northerly winds blowing. Some patchy frost is possible in some locations. Mountain basin locations were quite chilly, with Chester at only 18 degrees.
Wildfire smoke from the Camp Fire kept temperatures cooler over a significant portion of the area on Friday due to blocking some heating by the sun. This is expected to be a factor again today, mainly over the Valley south of Paradise, due to light northerly winds. Poor air quality is also expected. Go to airnow.gov for more information on your area.
Northerly winds pick up a bit this afternoon, though will be much lighter than they were over the past few days. Gusts up to 15 mph are possible over the northern Sacramento Valley late this afternoon. These winds will increase overnight as another disturbance drops southward into the Great Basin, tightening the pressure gradient. The strongest gradient develops over the mountains and foothills SW-NE Saturday night through Sunday. Gusts to 50 mph are possible over ridges and through canyons. Winds on the west side of the Sacramento Valley may gust to 25-30 mph. Although these winds may not be quite as strong as Wednesday night and Thursday, the combination of gusty winds and lowering humidity will lead to critical fire weather conditions Saturday evening into Monday morning. A Red Flag Warning remains in effect for most of interior NorCal. Winds will remain gusty over the eastern foothills/mountains through Monday morning. Lighter winds are expected Monday afternoon as surface pressure gradients relax.
Dry conditions will prevail across interior NorCal as high pressure remains in control. High temperatures will continue to run about 5 to 10 degrees above normal. Look for Valley highs in the 70s (mid/upper 60s under smoke), and 50s/60s over the mountains. Overnight lows expected in the mid 30s to low 40s across the Valley.
Extended Discussion (Wednesday through Saturday)
Dry weather with mild days and cool nights expected to continue during the second half of next week as a strong ridge remains over the West downstream of a deepening trough over the eastern Pacific. No strong wind events are expected. The mountain areas and far northern portion of the forecast area may see a few showers by next Saturday as the initial batch of short-wave energy moves ashore, but confidence in details remains low.