Tag Archives: Omega Block

A week has passed and the Eastern Pacific weather pattern lingers.

March 08, 2019

A week has passed since my last blog on the current Pacific weather pattern.  The Blocking Eastern Pacific weather pattern lingers, and that means more activity weather for many parts of the country. First chart is of course the 500 mb flow across the Pacific.  I have used the blue color to outline the now familiar Omega configuration of the Blocking pattern. The red line shows the tropical connection that also lingers in the Eastern Pacific.  The 500 mb chart is from  Friday morning at 12z UTC.

The GOES West snapshots below illustrates how the trail of clouds and moisture runs from south of the Hawaiian Islands northeast all the way to the Central US. For reference it is 2500 miles from Hawaii to California , so this plume of moisture may stretch as much as 4000 or 5000 miles from the Equatorial Pacific to Central portions of North America.  The first picture is from Thursday evening, 00z UTC March 08.

The second frame is from late Friday afternoon or 2200z UTC.  In this second picture the cloud pattern over the Alaskan panhandle actually shows the same Omega configuration . It also shows moisture surging into North America as our Pacific disturbance moves east.

Along with keeping the west coast active with snow and rain, and this past week even a round of thunder and lightning over Southern California.  This most recent system is headed toward the Central US. with a threat for severe spring weather. So,  similar to last weekend,  a storm system with a Pacific and Arctic connection will lead to more active weather including the threat of tornadoes.  This weekend Saturday appears to be the day with the greatest threat of severe weather. The threat for tornadoes is  greatest in the center of the highlighted area in the Storm Prediction Center’s graphic below.

Along with another round of severe weather,  moisture will also mix with the arctic air leading to more snow for the Upper Midwest. Winter Storm Warnings spread across parts of seven states.

On the lighter side, the snow just keeps piling up across the mountains of the west.

The Mineral King webcam is located at an elevation of 7830 feet in  Southern Sequoia  National Park. The Park is reporting a snow depth of 108 inches, or 9 feet.

Friday March 08, 2019 at1209pm

Below, the same location pictured last year in early March of 2018, note not only is the cabin mostly visible, you can also see the outline of the corral used in the summer months.

Monday March 05, 2018

A few weeks earlier last year when the slopes of the Sierra were void of snow in the middle of February.  All this to illustrate what a stormy 5 or 6 week stretch we have seen in the west since late January.

February 18, 2018

Mineral King and Farewell Gap webcams can be found at:


If you like the blog you will love the book.

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Parade of storms continues nationwide in early March

Parade of storms continues nationwide in early March

Friday March 01, 2019

Before we can take a breath, relax and look back an incredible February of weather extremes, March is about to roar like a lion.  What is called an Omega ( looks like Greek letter Omega ) Block has been a semi-permanent feature in the Eastern Pacific for weeks now.  I have made the attempt to use blue arrows to show path of cold arctic air and red for the tropical moisture, sometimes called The Pineapple express.  The ridge which makes up the Blocking pattern is not only bring above normal temperatures to Alaska, but notice it also directs  air from the Arctic southward toward the United States including the Pacific Northwest.

Below is the 500mb chart from very early on Friday March 1, 2019

GOES 17 or GOES west IR imaging for midday Friday March 1st shows the next storm lurking west of California.  After impressing central and southern California, this storm will cross the country during the first weekend in the month of March bring a variety of adverse weather pretty much from coast to coast. Another shot of impressive Arctic air will plunge into the central and eastern US following the storm. Early March will look and feel a lot like much of February did for across the nation.

Below I offer one example of what this weather pattern has meant to one of our National Parks. At 6000 feet in the Southern Cascades of Oregon, the south entrance to Crater Lake, the webcam pictures tell quite a story.  First, this year, then last March, and finally the El Niño season of 2016.

The observation from the Anne Springs Entrance shows a snow depth of 129 inches on Friday March 1st.  Up at the rim of the crater the report is 140 inches of snow on the ground.

Last  year on March 1st, 2018,  notice the fallen tree at an angle and compare to picture above.

And finally same view on March 01, 2016, this was the winter of the strong  2015-2016 El Niño.  So this year’s short, weak El Niño has out performed the stronger record event in terms of snow pack at least at this location at this point in the season.

You can learn more in my e-book El Niño:  The WILD side of the weather cycle…
What we know, what we don’t, and WHY you should care!

The book was written for the record 2015-2016 event, but much of the material is also relevant for this year’s much weaker event.

We will review some of this winter’s extreme weather in the coming days. We saw record February snow in several locations, including a brief surprise accumulation in Las Vegas, Nevada. We saw historic rain and flooding across parts of the south and in California. We have also experienced a record cold polar vortex.

So in brief, it has been stormy, it is stormy, and it will continue to be stormy, until the season changes, the arctic air stays in the arctic, and the affect of this current El Niño begins to fade.

If you like the blog you will love the book.

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