February has ended- with an eye to March. Will March comes in like a lion or a lamb? How will it go out? But most importantly, is there any hope for salvaging this rainy season?
March is typically the second wettest month of the year in the south valley with a climatological average of 1.21” for Bakersfield. Coming on the heels of a February which only rendered 23% of normal rainfall, March appears to be getting ready to disappoint us again. In fact, January and February have combined to only produce 5 rain days so far this year. That is only 36% of normal.
While medium range models are indicating an uptick in favorable weather patterns for rain during the middle of March, long range tools continue to support drier days than we need. La Nina, the perennial ocean condition that has dictated our current sparse moisture scenario, is predicted by several blended computer models to remain in force through the end of spring 2012. There is even some indication that an El Nino may develop toward autumn, but that is objectively predicted with a 30% confidence at this time. El Nino would bring more rain than usual, were it to happen this autumn. So, I’m expecting more rainfall in March than in February (from .50-1.00” in the south valley). But we will have to depend on last year’s surplus to tide us through. March should come in AND go out like a lamb. There may, however, be a brief lion-like phase in the middle of the month.
Probabilities of warmer than average temperatures for the middle of summer are going up- according to the Climate Prediction Center. Hot and dry weather is not uncommon for central California through the summer, but more than 3 heat waves are somewhat anomalous. We may be trending toward 4 or more heat waves judging from this vantage point at the start of March. Forecast skill peaks in late winter and also late summer. But accuracy suffers in late spring for a variety of reasons, including the fluidity of the atmosphere with its shift from a winter paradigm to a summer paradigm.
Meteorologists rely on a number of sophisticated tools in order to divine our weather fortunes for a season or two into the future. And, unfortunately, all tools are pointing to a weak rainy season remaining that way through the wet season finale. Normal rainfall totals rapidly decrease beginning in April. I have expected we may see slightly above normal rainfall in April alone, due to an active jet stream pattern interacting with a slowly diminishing La Nina effect. Severe weather episodes in the southern plains should once again run above normal this spring while we get a small boost in precipitation here in California. But after April it will turn dry and very hot. Hotter than average readings are expected in May, with triple digits possible before the first of June.