WeatherWatcher: Forecast, Rainfall totals, El Niño

• Forecast
• Rain graphs
• ENSO (El Niño Southern Oscillation) update

Forecast: We have yet another heat wave moving through the region on Tuesday and Wednesday. Sunny skies until Thursday. Temperatures Tuesday appear to likely reach the low-mid 90's and upper 80's on Wednesday. Thursday a new weather system will move in similar to last week with showers, possibly some thunderstorms for Thursday and Friday. Temperatures will retreat back to the mid to lower 70's for a high. Next weekend looks mostly the same as this weekend has been.

Rain graphs: I recently had the question from several people regarding rainfall this spring and summer. Has it really been drier than normal? Short answer is yes, we've had a very dry spring and summer compared to the past 5 years. We are getting quite the relief in August here, however, with our 0.91 inches of rain on Friday from that lovely storm we had.

Here's the graph for total monthly rainfall compared to the 5 year average.

Here's another one for the total rain from January 1st - August 16th compared to normal.

Additionally for those who really want the daily view, here's the daily total's from January 1st - August 15th, 2015. You will probably want to click on the image for the larger original size to get a better look at the details. Axis on the side is inches.

ENSO Update: Now I want to talk about the El Niño, also a little about the "Blob" as Professor Nick Bond at the University of Washington has named it. The blob is more commonly known as the result of what a warm phase in the Pacific Decadal Oscillation can look like. First, however, let's talk about the El Niño.

At present the El Niño is very moderate to strong, depending on the section measured. Most areas of the central equatorial Pacific Ocean are averaging at 1.0°C above normal, with the eastern equatorial Pacific Ocean running around 2.0°C above normal. There is a 90% chance forecast that this El Niño is expected to continue through the winter and early spring. 

The Blob is here to stay in general, though we've had it with us now for two years, and historically it appears to have not lasted beyond the two year mark during what normally appears to be a cold phase PDO, so I suspect it may break down this winter or at least by the next winter 2016-2017. Otherwise that was the shortest cold phase PDO we've observed.

It is a common belief that El Niño means a warm and dry winter. This, is true under certain conditions, some of which is if the El Niño is a weak to moderate one, and if the Blob isn't hanging out off our coast. There are different variables in place this year.

Strong El Niño's tend to be a different beast. Adding that with the Blob and we really have something we haven't seen in several decades. From what I can tell with my own research we have two other what are called '   analogue years' that had similar sea surface temperatures and patterns going on globally. The winter of 1957-1958, and I want to say 1968-1969.

November 1958 got cold, but just a dusting of snow. January and February 1959 had 3 and 7 inches of snow respectively. Another year that had a strong El Niño and likely something like the blob was 1968-1969 where 22 inches of snow were recorded at Sea-tac in January, February reports 45 inches of snow, but I find that number hard to believe. If you or someone you know was in the area at that time and remembers the snow of that winter, or any other winter for that matter, I'd love to hear your story and welcome you to email it to me.

What this means for Shoreline and Lake Forest Park: We are still going to see some hot summer days breaking 90°F, maybe even into September. Though the storm track may try to stick to the south for California I think we might get some storms in for the fall, and winter as well.  I'm also going to suspect we might see a couple of snow events this winter, however I will admit that's still too far out to be very certain. I just don't want everyone to assume El Niño means we won't see lowland snow. When it's a strong one, the chances actually start to increase for lowland snow compared to a mild to moderate El Niño. 

For current weather conditions check out Shoreline Weather