What a difference a year makes. In mid-November 2014, the mountain peaks of the Sierra Nevada range were barren. This year, they are capped by two to three feet of snow in many areas.
“The wet/snowy season is off to a rapid start in the Intermountain West and West Coast States,” the U.S. Drought Monitor wrote in its report Thursday. “Snowpack is well above normal for this time of year in the Sierra Nevada and parts of Nevada where drought has seemed intractable.”
The National Weather Service (NWS) said Reno, Nev. is having its wettest start to a water year in records which date back to 1893. Its precipitation has been almost four times the average.
Can we thank this year’s El Niño event, which ranks among the strongest three ever recorded for this precipitation windfall?
Michelle L’Heureux, a climate analyst at the NWS Climate Prediction Center (CPC) says not so fast.
El Niño events are characterized by warmer than normal ocean temperatures in the equatorial Pacific which can lengthen and intensify that jet stream that carries storms into the Southwest. But L’Heureux says this telltale El Niño signal in the storm track isn’t yet apparent.
“I just polled a few folks [climate researchers at CPC) and I think the consensus is that we don’t really see much of an extended jet yet,” L’Heureux said in an email.
It’s not to say El Niño may not be indirectly enhancing the precipitation in the western states. “I don’t think it can be ruled out that El Niño is playing some role, but some more research has to be done,” L’Heureux said.
While stopping short of directly attributing the western storminess to El Niño, the NWS announced today that the strong El Niño is already having “significant global impacts” and is likely to persist through the winter. That’s when the connections between California weather systems and El Niño may become more apparent.
The El Niño enhanced moisture pipeline is sorely needed as drought conditions remain extreme to exceptional through much of California and western Nevada.
And it’s a stretch to say drought relief has truly commenced.
“[G]iven the long-term nature of the drought in much of the Far West, only scattered areas of improvement were noted [from the recent precipitation],” the U.S. Drought Monitor stated. “Areas where drought was more entrenched will need abundant precipitation to continue much farther into the wet season before any notable improvement could evolve.”
A group of seasonal prediction models offers a promising winter precipitation forecast for the drought areas – on balance calling for well above average precipitation through February.