Weather Wise - Weather Forecast
published: October 7th 2016
by: Brian Bledsoe
If you’ve been reading WeatherWise for the past several years, you know I place a HIGH value on what the oceans are doing when I am making a long range forecast. I think it is pretty interesting, the changes that have taken place during the past few years, and wanted to show those changes to you. The maps below represent the sea surface temperature anomalies during late September, since 2012. Red means warmer than normal water, while blue means colder than normal water. Check it out:
Pretty crazy, huh?! A couple of recent changes to note… The El Niño-Southern Oscillation (ESNO) region in the central/equatorial Pacific is MUCH cooler than last year, but not really threatening with a strong La Niña event. Also, the “blob” of warmer than normal water in the North Pacific has been shrinking and cooling, but it is still present. This will likely have a negative effect on California’s wet season... again.
Periodically, I like to give you an update on what the Pacific Decadal Oscillation is doing. The chart below shows the PDO (Pacific Decadal Oscillation) and its associated phases since 2005:
Refresher...when the PDO is in a positive/warm phase, we usually do not have much drought to worry about in the Western, Central and Southern Plains. When it is in a negative/cold phase, the opposite is usually true. Since early 2014, the PDO has been in a positive/warm phase, and has essentially helped keep our drought concerns at bay. Recently, the PDO has cooled considerably, and is threatening to turn neutral or negative before the year is over. This eventual transition has had me concerned for a while, as I believe we have to start thinking about drought again. Maybe not right away, but I certainly think our recent wettest times are behind us and the times than lie ahead will be drier. I’m not trying to be a doomsayer, but this is something that I think we all need to be thinking about.