Friday, March 6, 2015

NWS expert: Weak El Nino won't end drought

In the months that El Nino conditions have been developing in the Pacific, forecasters and water officials have been warning that it wouldn't be strong enough to end the doubt. Now with the arrival of the so-called "weird" El Nino (a term the AP no doubt hopes you'll associate with manmade global warming), Michelle Mead, the National Weather Service's warning coordinator in Sacramento, is emphasizing that it won't change California's prospects for precipitation.

She explains:
Well, it took all winter, but the atmosphere finally decided to play nice with the sea surface temperatures and resulted in a Weak El Niño connection. This means convection (Showers and Thunderstorms) have shifted from the Western Pacific to the mid Pacific region, near the dateline. See image below of Convective signature of Neutral (top) vs El Niño (bottom). As a result, CPC issued an El Niño Advisory with this morning's CPC ENSO diagnostic discussion. Basically, it states El Niño has officially emerged, however in a weak state. As you'll recall from emails we've been sending all last fall and this winter, weak El Niño's have little to no impact on California precipitation. El Niño has it's strongest influence during the winter/wet months. Spring officially begins March 20th. Therefore, due to the weak El Nino, we are not expecting significant impacts for California; no end to the drought.
There is an approximately 50-60% chance that El Niño conditions will continue through Summer 2015.

Main takeaway:

Due to the expected weak strength, widespread or significant global impacts are not anticipated
However, certain impacts often associated with El Niño may appear in some locations during the Northern Hemisphere spring 2015
Significant impacts for California are not expected
No improvement of the drought
The mean of the models (bold yellow line in image below) predicts the Sea Surface Temperatures (SST) anomalies to remain at weak El Niño levels from now through summer 2015
If you'd like a bit more background into this latest El Niño Advisory update, please visit the ENSO Blog. They give a less technically worded discussion on the latest update. [...]

Remember, El Niño is not a good predictor of precipitation across northern California.

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