In the midst of the driest period on record in California, weather forecast models have in instances thrown hints of significant change in large-scale airflow which would bring badly needed rain and snow to the Golden State. Until now, these model “suggestions” have been long-shots, every time failing to verify, falling prey to a persistent, stubborn pattern of western U.S. high pressure.
At the present time, weak low pressure west of Los Angeles has spread sub-tropical cloudiness across the region with a chance for isolated local light sprinkles today.
Once again, longer range forecast models are suggesting a major change in surface and upper level wind and pressure patterns within the 16-day time frame of the GFS model. The difference this time, is that this change is persisting with each new model run, and lies within the next ten days, giving it at least a 50-50 chance of coming to fruition.
Similar suggestions on different occasions during December and January occurred beyond the ten-day window, and were evident on only one or two model runs, failing to show lasting consistence.
Successive model runs during the past few days now continue to show a developing pattern which should finally bring an eastern Pacific storm track further south, first affecting northern California beginning around Tuesday, January 28th and more significantly two days later with potentially significant rain and mountain snow.
Going out further, southern California may see an increase in cloudiness and chances for some showers around February 2nd or 3rd. At this point, nothing heavy seems imminent for greater Los Angeles, but a major cool down and overall increase in humidity might lessen what has been possibly the worst season for fire danger ever.
Satellite images show a developing storm pattern to the west of California, which may be strong enough to finally break down blocking high pressure. Not only would this affect the entire western U.S., it may finally bring much needed relief to the frigid 'polar vortex' conditions plaguing much of the nation east of the Rockies.
Once again, mathematical and statistical odds favor this; hopefully models will continue this trend, increasing the odds with each passing day.