April 9, 2020 – Lingering showers today, mainly over the Sierra Nevada south of I-80. Otherwise, dry and warmer with locally gusty northerly wind at times in the Central Valley.
Threat of wrap-around showers continues today and tonight as the slow moving upper level low continues to linger over SoCal. The best chances for showers will be over the Sierra, mainly south of I-80, with some light high elevation snow. Current radar imagery depicts shower activity generally around Highway 4 southward. A band of this precipitation is spread northward and westward, with Modesto and Turlock likely to see some light rain showers shortly. over the southeastern portions of the forecast area. Rainfall amounts should remain fairly light, with afternoon showers in the foothills and mountains spreading as far north as eastern Butte County and western Plumas County. The Sierra Crest from Highway 50 southward could see a couple inches of snow.
Elsewhere, dry weather continues, though increased cloud cover and a shift to southerly winds will keep temperatures cooler than yesterday. The northern Sacramento Valley should see the biggest change, with highs around 70 versus the mid 80s that happened on Thursday. and mild temperatures continue.
Some breezy southerly winds are possible early this evening, gusting to around 20-25 mph over the central Sacramento Valley.
Shower activity tapers off Friday as upper ridging increases over NorCal. Valley highs will reach the low to mid 70s by Friday, followed by low 70s to low 80s over the weekend. These forecast highs will be 5 to 10 degrees above climatology. Saturday will be a few degrees warmer, with the low 80s potentially returning to the northern Sacramento Valley.
Extended Discussion (Monday through Thursday)
The configuration of an offshore ridge and amplifying flow over the Intermountain West will support a period of breezy northerly winds on Monday. Shortwave energy traversing this trough could graze the Sierra spawning scattered showers over the higher elevations. Thereafter, some increase in heights are expected as the eastern Pacific ridge drifts eastward. This will support a gradual uptick in temperatures along with dry weather ahead. By mid-week, some of the guidance carries a weak upper low which may approach the coast. However, there is not the greatest consistency amongst the global models which leads to a decrease in confidence. High temperatures during the week will remain in the mid/upper 70s, locally reaching the low 80s across the northern Sacramento Valley. This is around 5 to 10 degrees above climatology for mid- April.