A February weather pattern marked by high pressure, sun and mostly pleasant days has given way in March to one that has brought a lowering of pressure and the arrival of cold and often rainy weather.

Don’t expect that to change anytime soon, the National Weather Service said.

“The hemispheric pattern is active, and the (system) is locking onto some water vapor,” NWS meteorologist Rick Canepa said early Tuesday. “So it looks favorable for (storm) development into at least mid-month. It’s not unusual. March is normally our fourth-wettest month.”

The next step in the storm development is expected by late Tuesday to bring a decent amount of rain to the South Bay and Central Coast. Canepa said that rain could last into Wednesday morning before another “reinforcement coming behind it” is expected to bring additional rain late Wednesday into Thursday.

The weather service said the most intense rain from both systems will be in the Peninsula, South Bay, Central Coast and Santa Cruz Mountains. Those areas all are expected to receive between a half-inch to a full inch of rain.

Rainfall is expected to be considerably less in the East Bay and North Bay. Livermore should get between two-tenths and a half-inch, while areas of Contra Costa, Alameda, Napa and Sonoma counties are expected to receive only a smattering of rain.

“There will be a little more statewide precipitation with the second one,” Canepa said.

The rain will fall amid continued cold temperatures. Temperatures are not expected to rise above the 50s until Friday, and the overnight lows are expected to dip into the low 40s in most places. They will be in the high 30s in areas of the far East Bay.

That will change a bit over the weekend, according to Canepa. Low temperatures overnight will remain just as low, but the high temperatures are expected to rise back into the mid-60s amid dry skies.

More rain will arrive next week. Canepa said more progress in the weather pattern will help them determine how severe that precipitation will be.