California — A Major Christmas-Week Pattern Shift Takes Shape, After nearly a month of unusually warm and dry conditions across the Desert Southwest and Southern California, a significant shift in the weather pattern is now developing just in time for the holiday period. Atmospheric indicators, Pacific satellite loops, and CPC guidance all point to a stronger, more aggressive storm track setting up and targeting the West Coast between December 22 and December 28.
This change is being driven by a weakening ridge over California and an increasingly active Pacific jet extension stretching from the western Pacific across the ocean toward the West Coast.
Stronger Troughing Will Allow Storms to Dig Deeper Into California
Forecast models show progressively deeper troughs arriving next week, pushing storms farther south with each passing day. This pattern will allow widespread unsettled weather to develop across:
- Southern California
- Central California
- Northern California
Initial impacts may begin around Christmas Eve, though some guidance suggests stormy conditions could arrive slightly earlier.
This shift will also feed on warmer-than-normal Pacific moisture, lifting snow levels at first before colder air behind each system lowers them again.
Warmer Pacific Moisture Could Raise Snow Levels Before They Fall
Moisture feeding into the storm system is expected to originate from tropical and subtropical regions, leading to elevated snow levels of 7,000–8,000 feet during the early phases of the event…