Good Morning Weather2020 Bloggers,

A rather fascinating weather pattern is evolving right before our eyes. A blocking pattern is strengthening, and once it forms over the weekend it will be exciting to see what happens next as the models will not be able to handle the breakdown of the block very well at all.  I will try to cover this in my video, and I am also posting the maps below. It’s FRIDAY!

Todays Video Explanation: The Blocking Pattern & What It Means

A Blocking Patter & Lake Tahoe Basin Braces For An Extreme Weather Event from Weather2020 on Vimeo.

Again, please watch the video. I did it in one take so I hope it makes sense.  In the video I am discussing these following graphics as this weather pattern sets up:

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The map above shows the 500 mb flow (around 18,000 feet above us) valid tonight, and the map below shows how the block strengthens by the end of the weekend:

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If you just look at the flow over the United States and didn’t know about the block, the northern branch that comes over the top of this block and the very cold air mass that is in place, then you would think it is a rather warm weather pattern.  This is not the case, however, and this is just a fascinating pattern evolving before our eyes. There is a big warm-up likely, as a result of what is happening in that southern branch around that big eastern Pacific low that is forming. The question is what will happen next?  And, the even bigger question is how will the “atmospheric river” set up over the Sierra Nevada mountains in this next seven day stretch. There is a good chance of an extreme weather event. These are hard to predict. Will this produce an extreme rain event of 5 to 10 inches liquid, or could it be 20 inches or more and really become extreme? And, what will the snow levels be? Will they be as high as 9,000 feet, or at times will it drop to 6,000 feet. Lake Tahoe is around 6,240 feet above sea level with the mountains approaching 11,000 feet around the Tahoe Basin.

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Here is another way of looking at the high over low block:

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Now, what happens next is extremely important for next weekend. The computer models are all over the place and for a good reason. The models are error ridden anyway. Using the LRC I know that a storm system should be approaching Kansas City around the 16th or 17th. But, the LRC is not perfect and it could be off a day, two, or three. We have made some excellent and specific forecasts over the past years using this great new method of weather forecasting. When we are wrong in our forecast it is almost always forecast error and not the LRC itself.  This next map shows a forecast of the complete breakdown of that block and the storm I am expecting to show up on the 16th or 17th in the plains. This is the day 10 European model.

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My biggest point is…..be aware of the models while this block is established and begins to break down.  The models are almost always wrong anyway from five days out and beyond.  We will know a lot more in the coming days.

The AO and NAO indexes have been forecast to dip negative, but it just has not been happening.  If these do dip deeper negative, and I am still expecting and forecasting it to happen in February, then our weather could get a jolt of bigger excitement.

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Have a great day and thank you for sharing in this LRC Weather Experience. Let me know if you have any questions.

Gary