WeatherWhys Blog

Wet February Leads to a Wet March

Wet February Leads to a Wet March
File photo

The hills are alive with greenery and foliage bursting out like it was spring. Of course, the Vernal Equinox (first day of spring) is still nearly a month away.

This wet winter is chiefly responsible for the flash of color in our hills. Almonds trees sport white and pink buds that turn the south valley into a feast for the eyes- a palate of spring’s promise of fruitfulness to come. To date, Bakersfield is running about 75% of total normal rainfall for the water year- and the middle of the rainy season is still about 2 weeks in the future. This is roughly an inch above normal. February is the third month in a row of sharply wetter than average conditions. And now it appears that this trend will continue for at least another month, probably two.

Our current El Nino pattern is expected to persist, characterized by a strong polar jet stream at decidedly low latitudes. Earlier this season I noted wind speeds of nearly 250 MPH in the upper atmosphere driving powerful storm systems. Both Storms Poseidon (October) and Ares (January) were widespread wet and windy affairs thanks to the extremely strong winds in the upper troposphere. Computer models are indicating something similar may develop by the middle of March again. In the meantime, we should expect showers early this week, a small system about Wednesday and then a more significant storm approaching the state late Friday and Saturday. There is the chance next weekend’s storm could bring snow to the passes, windy weather along the coast and heavy rainfall in places that no longer can withstand much additional precipitation.

The El Nino phenomenon is continuing, but has shown signs of weakening. Nonetheless, its effect will persist through late spring. That means a jackpot water year for California, but other things too. For example, a severe drought has hit Venezuela with hydroelectric power generation so impacted by low water levels that rolling black outs have been occurring. It is also very dry in Australia and Indonesia with heat, dust storms and wildfires. This dry weather, a direct result of the El Nino Southern Oscillation (ENSO), extends as far as the Hawaiian Islands. Since December, Honolulu has received only 29% of their normal rainfall. These past 3 months have yielded 2.13”, compared with last year’s 11.45” during the same period. El Nino’s effect is world wide. Tremendous flooding has occurred this week on the Portuguese Madeira Islands, about 550 miles west of Casablanca, Morocco. So far more than 40 people have been reported killed and over 100 injured from intense flooding in an Atlantic Ocean location that receives about 25 inches of rainfall a year. More than 3 inches fell in one hour during the height of the flooding that can be traced to a strong jet stream very far south brought about by ENSO now occurring in the central Pacific.

These extreme weather events are rare, but not during El Nino years. Atlantic hurricanes are minimized by the phenomenon and just as tropical activity in the Atlantic was low in 2009, it is anticipated that 2010 will start off quiet as El Nino finishes up. The bulk of the 2010 hurricane season in late summer and autumn will likely be a bit more active than last year. March will officially mark the 10 consecutive month of this ENSO event. A typical event will last between 10 and 15 months and adds about 25% more precipitation to rain gauges in the central valley of California. That makes Californians beneficiaries of this cyclic weather event.