Dry Spell Expected to Persist Until Mid-February, or Longer

"It's turned into an unusually dry winter for Northern California, and that pattern, thanks to a ridge of high pressure, is going to continue for at least the first 10 days of February. As the Chronicle meteorology team tells us, the dry and balmy conditions will be with us through Super Bowl Weekend and beyond, continuing a pattern that has left the Sierra snowpack mighty low."

"The weather could shift on or after February 10 in Northern California, bringing more seasonal wetness and cold. According to the European Centre for Medium-Range Weather Forecasts, the 10th is the first day this month when that ridge of high pressure is expected to go away. But other forecast models aren't showing this, and the Chronicle team suggests that the weather could remain uncertain, with likely below-normal precipitation, into the middle of the month and possibly beyond."

"A polar vortex, and the fading La Nina pattern in the Pacific, have been contributing to the winter weather pattern that has left the West fairly warm and the East and other parts of the country unusually cold. In any event, look for the rest of the country to be jealous as live shots from San Francisco and Santa Clara this weekend show bright sunny skies and football fans without winter coats on."

Northern California is experiencing an unusually dry, warm winter driven by a persistent ridge of high pressure that is forecast to persist at least through the first 10 days of February. Dry, balmy conditions are expected through Super Bowl weekend, contributing to a much-reduced Sierra snowpack. Fall rains have so far kept the state out of drought, but continued dryness could reverse that status. Forecasts diverge on whether the ridge will break around February 10; the ECMWF indicates the ridge may dissipate then, while other models keep it. A polar vortex and a fading La Niña pattern have left the West warm and parts of the East unusually cold, and below-normal precipitation is likely into mid-February, maintaining uncertainty.

Read at sfist.com