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Weather Outlook

April 25, 2017

Summary- There is a tendency for troughing near and just west of N California, before and after May 1st. The sea surface temperature anomaly (SSTA) pattern in the central N Pacific is strong and persistent enough to continue the tendency for troughing through May and possibly into early June near and over the Calif coast. Forcing for troughs over western Mexico will continue. A classic, moderate to strong El Niño anomaly pattern is expected to develop per the current SSTA pattern and the NMME (North American Multi-Model Ensemble): Time frame- later in the summer and in autumn.

April 11, 2017

Summary- The tendency for troughing near and west of N California continues, even as we approach the normal end of the season. The sea surface temperature anomaly (SSTA) pattern in the central N Pacific is strong and persistent enough to continue the tendency for troughing through May and possibly into June. Forcing for troughs over the southwestern US may still be related to the currently weak El Niño, although seasonal factors that affect El Niño’s influence decrease with approach of summer. A classic, moderate to strong El Niño anomaly pattern is starting to develop, as shown by the current SSTA pattern, and the forecast developments shown by the North American Multi-model Ensemble (NMME) in the early fall.

April 4, 2017

Summary- The brief break in the rains ends Thursday, April 6th. The tendency for troughing near and west of N California continues, even as we approach the normal end of the season. Forcing for troughs over the southwestern US may still be related to the currently weak El Niño, although seasonal factors that affect El Niño’s influence are decreasing with approach of summer.