There are more indications that the climate system is rapidly moving toward La NIna conditions. Sea surface temperature anomalies of -2C are now evident in the east-central Pacific. However, the west Pacific Ocean west of the dateline remains warm and there is an MJO signal moving eastward around 10S.
Satellite images show current regions of organized convection are centered around west Australia and the SPCZ. Daily SST anomalies and totals show the warmth west of the dateline where convection is currrently suppressed. Time-longitude diagrams of outgoing longwave radiation (proxy for deep convection) show the MJO signal in the left panel and considerable westward drift to convection once it develops in a region.
The 250 mb vector wind field for 6 March 2007 (Tuesday) illustrates a complicated Pacific-North American circulation pattern with two anticyclones split by a trough over the Gulf of Alaska. Best developments have been occurring with the ridge and associated anomalies over the west Pacific which appear to be responding to tropical forcing seen in the satellite images. The model ensemble forecasts are not favorable for rain in the northern California region within the next week and continue pessimistic into week 2. The following link is a posting on Ed Berry's from yesterday, for additional information.
Klaus Weickmann and Ed Berry