Hahaha! Welcome to the longest post I’ve probably ever written! I cover a lot of content in this post, and it is organized in the following order: 1.) the forecast, 2.) my thoughts on this upcoming winter, 3.) a little lesson on inversions and why we have them in winter, and then lastly, 4.) a little reminder on how ensembles work. This post has been days in the making and it’s long. If you only want the forecast then read just the top portion only, but if you want something long to read, then keep on going!! Because of all the content I have in this post, I recommend you view it from the website itself to ensure the best experience specifically with the slider tools. Here’s a link to the website: https://bryanweatheralert.com/

The forecast

The weather has remained fairly calm and stable the past few days. Cold nights and mornings followed by decently mild afternoons, and this will continue for a few more days. The mornings will especially continue to be downright cold. Lows in the Salem area this Sunday morning ranged from 27 to 30 degrees depending on location. That would be cold even by December standards, so considering the fact that it’s not even November yet makes it all the more impressive.

The forecast is pretty cut and dry as we remain in this cool, but clear and sunny pattern through Wednesday morning. Wednesday afternoon and evening could be damp with showers moving in. Thursday marks a distinct switch to much rainier and stormier weather. In fact, Thursday is looking like a real soaker! This means you all need to get out and enjoy the dry and sunny weather while it is with us.

My winter outlook thoughts

Many experts gathered Saturday (the 28th) up at OMSI for an annual winter weather forecasting meeting. Presenters often review how well their forecasts turned out from the previous winter before taking a stab at the upcoming winter season. Interesting to say the least.

I don’t really forecast what a whole winter will bring as I think there are far too many variables; however, I get asked a lot and it is sort of fun guess. I look at a wide range of data including current trends, past years which had similar sea surface temperature anomalies, past years with similar upper level patterns, and other factors. Years with similarities are known as analog years. These analog years helps steer my best guess for an upcoming winter more than anything else. Way back in the beginning of August I gave a peak at what MIGHT lay ahead. I actually feel like that guess has held up quite well with a link to my forecast from August if you wish to review how I have faired so far. Today I figured I would just add to that guess refining it some since this is the time of year when all the “experts” give their best guesses haha.

For starters, it’s important to remember that we are in an El Nino pattern across the globe. This is based largely off of the sea surface temperatures west of equatorial South America, and yes, this does have an effect on the weather around the world including right here in Oregon. Based on the various factors I take into account, this is what I’m thinking for the months of November through March:

1.) Near average precip. NOAA and the NWS both will show and share maps on social media indicating we have a dry winter on the way, but I have to disagree. I really think we will end up right near average for precipitation when all is said and done. Many of these El Nino winters end up having one or maybe two months of very wet weather with the rest of the months being on the drier side of things. Add everything together and we end up near average. Again, just my best guess. Below is a fun map showing the climate divisions of the continental United States. This map takes precipitation data from previous years I manually plugged into it. The years I chose are all decent analog years – in my opinion.

Notice how the Willamette Valley in particular has no coloring. This indicates that most of these years ended up somewhere close to average when it come to rainfall/melted snow. This is why I’m leaning towards a fairly average year in the rainfall category.

2.) Warmer than normal temps. This guess is not due to any climate change affects. Afterall, we just had a colder than normal winter last winter which falls more in line with a typical La Nina winter. Unfortunately, we are not in La Nina, instead we have the wild “older” brother El Nino, and El Nino winters consistently end up on the warmer side of average. Warmer than average does not mean no snow or arctic blasts, nor does it mean a bad ski season which I will address in point number 3.

This next map shows how each climate division of the country faired in regards to temperature during these analog years. You may notice the Willamette Valley has no “warm coloring” and that is mainly due to the very cold temperatures from one of these analog years sort of throwing off the rest (1972). Fun fact, Salem’s coldest temperature ever recorded took place in December 1972 when it dropped to negative 12 degrees Fahrenheit! All the other years by and large ended up slightly warmer than average. I also consider other global patterns and conditions when I make these guesses, and I have a feeling this year will end up on the slightly warmer side. 1972 is just proof that exceptions do happen.

3.) Expect a decent ski year, but not top tier. El Nino can be notorious for a few things. The first being that unlike their counterpart “La Nina,” El Nino winters rarely have big snowpacks in lower elevation mountains like the Coast Range or foothill locations like Idanha or Detroit. Two, the snow is typically on the wetter side versus being more powdery, and this is due to the slightly warmer nature of the storms. It takes a colder airmass to produce real powdery snow, and while it does happen in El Nino winters, typically warmer storm systems are not far behind.

One other note is some of our very worst ski seasons have taken place during weak El Nino winters, but this is not a weak El Nino by any means. This El Nino will go down as a moderate to strong one which does change things, and this brings me to another point. I find it lazy that these national weather and forecasting services don’t take a few minutes to distinguish between the effects of weak and strong El Ninos. Use the slider tool to see the differences between the weak and strong El Nino winters.

There is a significant difference between weak and strong El Ninos, and so it is discouraging to see a broad brushed and effortless maps like this one below from NOAA shared all over the internet. Some of these people are getting paid 6 digit figures to make these forecasts, and this is the best they can do?? When you look at the actual data, like the data I just provided, there is nothing to support that Alaska, the west coast, the mid west, and the eastern seaboard all have higher probabilities of seeing a warmer than normal winter during the same winter.

Again, to help illustrate the differences between weak and strong El Nino winters, check out the differences in precipitation patterns during both weak and strong El Nino winters.

4.) Many of these El Nino winters had a lot of weather action right in the heart of winter – think December and January including arctic blasts and snow events. I feel we have an increased chance of seeing snow and cold during these two months whereas in other years it seems February has been the month for snow and ice.

Final thoughts

Expect very rainy and stormy periods (this includes elevated chances for significant windstorms also) to balance out the dry times this winter. When all is said and done, Salem should end up close to average for precip. Expect a relatively warmer than usual winter. Expect a decent ski season, but not a top tier season, and lastly, I expect we will see some sort of snow, ice and or arctic blast this winter, but as mentioned earlier, the chances are higher these wintry events will take place in December or January.

One big wildcard is February. There seems to be a clear trend for more snow and ice events in February than what we saw in the past. As we stand today, 5 of the past 7 winters have been La Ninas which tend to provide more optimal conditions for February snow, but one of the past 7 years 2018/2019) was an El Nino and it also gave Salem and the Willamette Valley a cold and snowy February, so what is going on? Is February becoming snowier, or was February 2019 an exception? Afterall, there have always been exceptions to the rules “insert 1972” lol. So yes, I’m curious to see what transpires this winter. These next two images are curtesy of Mark Nelson over at Fox 12 Oregon. He regularly does a nice job of explaining what is going on with the weather, and he does a fantastic job of putting together graphics which is why he has always been hands down my favorite go to TV weather person.

Make sure to use the slider tool to get the full experience haha! Two things stand out to me with one being the total amount of snow did go down by about 20 inches between these two time frames which is fairly significant. Two, look at the drastic change in snowfall for February! Big shift upward there, so again, I’m extremely curious to see what happens this winter. I guess a third thing I noticed is there has been less snow in November lately. November snow has always been rare, but 2011 and then going back to 2006 are the last two years we widespread valley snowfall in November, and neither of those years brought very much. One of these years one would expect to see a good early season November snow event….

Welcome to Inversion season!

Every fall it happens. The sun grows weaker and weaker, and the days grow shorter and shorter causing a phenomenon known as an “inversion.” Inversions take place due to several factors: 1.) Cold air is denser/heavier than warm air which causes it to sink to the surface. 2.) A weak sun angle cannot sufficiently warm the surface during this time of year (now through February). 3.) The days are also shorter which further limits how effective the sun is at warming us up. 4.) Consequently, shorter days equals longer nights of course, so we start out cooler and cooler as fall goes on.

The upper level air pattern which will be in place for Monday is almost identical to the pattern which brought us 80+ degree weather just a few weeks ago and which brought us 90 degree weather back in September, so it’s absolutely amazing to me how the length of the days and the angle of the sun can drastically alters the weather we experience in Salem. Here’s a nice little visual for all the visual learners out there. This just shows how much the angle of the sun drops from summer to winter. This is also why we can have days where the fog never burns off or goes away completely. The sun is just too weak to burn it off this time of year.

Ensembles

Want to keep reading? I’m really on a roll with this post, so why stop now? Haha! Every year or so I like to share charts like this one below to help illustrate how “ensembles” work, and how important of a role they play in forecasting the weather. Ensembles are a collection of all the different forecasts any given computer model has generated. For the most part, I rely more heavily on a European weather forecasting model than on any of the American models. Gasp! I love America, and you all know that about me; however, our weather models are just not to speed with the Europeans. I guess we are too busy with important issues like trying to decide which bathrooms people should use lol, but I digress…. Anyway, these computer models spit out a range of possible outcomes for the weather usually two or four times a day.

An ensemble chart like the one below shows 51 possible outcomes counting a “control” run. These 51 possible outcomes give forecasters a better idea of what will actually happen versus looking at an individual run. Unfortunately many apps and forecasters out there are base their forecasts off of individual runs rather than trends in the ensembles. This is why (especially in winter) your weather apps can swing wildly from rain to sun to showers to snow and back to sun again within a few days. Time goes from left to right on the chart below with each individual horizontal line representing one possible outcome. This specific chart shows 24 hour precipitation, but with some overlap between 12 hour periods, so focus on the general theme and not as much on the actual numbers.

From looking at this chart there are three things which really stand out: 1.) We will stay dry through Wednesday. 2.) The rain returns in full force by Thursday November 2nd. 3.) We stay in a wet pattern through at least the 13th with no sign of a big break in the rain. I’m sure we will see a couple dry days mixed in; however, we are clearly headed into a long stretch of rainy and stormy weather, so buckle up!

I hope this all was interesting for you! Yes, it was a LONG read, but I tried to pack it with a lot of “fun” information, and I felt like right before winter was an appropriate time to do it. I don’t know about you, but I think we are ready for winter now haha! 🙂

Take care, stay safe, enjoy the dry weather, be ready for a soaking on Thursday, and look for another update probably late in the week. 🙂