For multiple sequences, Pfold should still be able to perform even better. Chicago and Des Moines will really be ‘game-time decisions’, as upper air thermal profiles are still a little murky and will ultimately determine how much liquid and snow falls over these cities. Since the relationship is far from perfect, the PDO does deserve its own little section in our pre-season synopsis. There is a portion of the Storm Prediction Center’s text outlook that I’d like to share; for some of you, it may be a little complicated, so I’ve underlined the parts that sum up the paragraph best. Which gets to the other parts of the revolution: the availability of very good amateur equipment (like the Davis Pro weather stations) and the omnipresence of the Internet. In fact, there are so many observations available today, that if we plotted them all the weather maps would turn black with them over many parts of the Northwest. In contrast, today there are certainly at least 100,000 surface stations that report hourly and distribute their data in real time via the Internet over the U.S., and several thousand such observations over Washington alone.

Both winters (2013-2014, 2014-2015) have ridging over the West Coast and troughing over the eastern U.S., but if you look closely there has been a subtle eastward shift of the pattern. This suggests that the anomalous conditions are not reflecting global warming, which has revved up substantially over that period. In summary, we’re entering this forecast period knowing the recent atmospheric regime is tilted in favor of colder temperatures for the United States. Sade Sati details: Sada sati is a very stressful period in one’s life, as it involves plenty of financial and mental stress. Dance music has many genres and over the years has fused with other types of music to create many infectious workout tracks to inspire you while challenging you to be a better cyclist. Let me give you a better view of this by showing you the anomalies (differences from climatology) of heights of the 500 hPa pressure surface (located at around 18,000 ft) for the last two winter seasons (Nov through Feb). You can think of 500 hPa height like pressure (higher heights mean higher pressure, etc.) Blue colors indicate lower than normal heights (a.k.a., troughs) and yellow/orange suggest higher than normal heights (ridges).

One early insight was that large areas of convection (thunderstorms) in the tropic Pacific Ocean, generally located over warmer than normal water, could create an atmospheric wave train that moved into the midlatitudes. The Thought Police even had agents walking around as normal people watching the citizens. Solar Activity is something that is worth watching this year. Why so strong this year? Why in in this configuration? We’ll work through why this is as we go on down the post. So the question of why our weather has been so unusual is really about the upper level wave train: why did it form? Fortunately, during the past few decades meteorologists have gained a deep knowledge of such wave trains, with much of the fundamental work done here at the University of Washington. As I have described in previous blogs (here and here), the proximate cause of the unusual weather has been a persistent ridge of high pressure (ridge) over the eastern Pacific and low pressure (trough) over the eastern U.S. Yes, the ridge is there, but it has moved much farther east, leaving us in a much drier position. Last year’s West Coast ridge was centered offshore and this year’s ridge is nearly on the coast.

Perhaps the most ominous sentence in this discussion is the last one, where the SPC indicates that any storms which do develop are expected to have significant severe weather associated with them. The tropical cyclone forecasts presented at this site are intended to convey only general information on current storms and must not be used to make life or death decisions or decisions relating to the protection of property. So for a very modest investment one can collect excellent quality information and make it instantly available to the world (something impossible two decades ago). You can rely on Weather the potential issues are many. And it is matter of time before all cars have internet capability–imagine if each reported temperature and other weather parameters in real-time as they drive around. The key point is that the observed sea surface temperature distribution in the tropics can forced the observed anomalous weather patterns in the midlatitudes. Our next point of focus is the PDO or Pacific Decadal Oscillation.