THE BIGGEST BLAST IN 30 YEARS...

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THE BIG BANG...

Early data from Tonga's recent violent volcanic eruption suggests it is the biggest since Mount Pinatubo in the Philippines 30 years ago. Shortly after the eruption massive ash clouds blotted out the sun, thunderclaps of booming shockwaves were heard (as far away as Alaska), and thousands of lightening strikes were seen. Satellites detected the ash cloud 24 miles above Earth's surface,. Oxford University research fellow Simon Proud indicated that this was the first time volcanic ash has been detected so high in Earth's atmosphere. Watch the eruption below.

Scientists however, general believe that the eruption won't affect Earth's climate much. Despite the apocalyptic proportions of the blast, which was documented in real time by several satellites, the amount of ash it contained was relatively small compared to other cataclysmic volcanic eruptions known from previous centuries.

NOT ENOUGH SULPHER DIOXIDE

Supervolcanoes like Tonga that spurt vast quantities of sulfur dioxide into higher layers of Earth's atmosphere can sometimes produce a measurable cooling effect on the planet's climate. This effect was detected, for example, after the 1991 eruption of Mount Pinatubo in the Philippines. That eruption, the second most powerful volcanic eruption of the 20th century, cooled down the planet in a way that was measurable for up to two years. But according to available data, Tonga blasted into the atmosphere only 400,000 metric tons of sulfur dioxide, about 2% of the amount of Mount Pinatubo.

"At this point then, the estimates of the amount of sulfur dioxide emitted by the Hunga-Tonga eruption is a small fraction of what was emitted by the eruption of Mount Pinatubo," Karen Rosenlof, an expert in atmospheric chemistry at the U.S. National Atmospheric and Oceanic Administration (NOAA), stated in an email. "Because of that, I would not expect to see a significant global surface temperature response."

Rosenlof added that even the Pinatubo aerosols only had a relatively short-term impact, measurable for about a year or two, which means that the Tonga volcano is certainly not going to buy humans time in their battle against climate change.

Volcanic eruptions for ages have had HUGE impacts on the global climate by cooling Earth. So it’s only natural to wonder, if the planet is affected by volcanic eruptions, can the El Nino Southern Oscillation be as well? After two major volcanic eruptions in the tropics in the late twentieth century (Mt. Pinatubo in 1991, El Chichón in 1982), the globe cooled over the next year and the tropical Pacific shifted into an El Niño a year after. A study using climate models, specifically of the Mt. Pinatubo eruption, seemed to indicate that the volcanic eruption primed the tropical Pacific to shift into an El Niño by reducing and slowing the tropical trade winds, which can kick start El Niño by allowing warmer water to slosh east.

Research indicates that enormous volcanic eruptions trigger El Niño events by pumping millions of tons of sulfur dioxide into the stratosphere, which then forms a sulfuric acid cloud, reflecting solar radiation and reducing the average global surface temperature. Studies have documented using sea surface temperature data since 1882, that large El Niño-like patterns followed four out of five big eruptions: Santa María (Guatemala) in October 1902, Mount Agung (Indonesia) in March 1963, El Chichón (Mexico) in April 1982 and Pinatubo in June 1991. However, with the Tonga event the amount of sulfur dioxide is again estimated to be only 2% of Pinatubo so El Nino impacts are expected to be minimal.

WHAT WENT UP HAS GONE DOWN...

I'm sure you noticed we had a bit of a change in our weather the past 24 hours. A dry but potent front sent temperatures tumbling and by evening readings were running 30-35 degrees older than just 24 hours earlier.

The stiff NW winds while lighter, will still be strong enough to create significant wind chills early Thursday in the range of 10-25 below zero, a few spots closing in on 30 below in the NW.

The majority of my area is under a wind chill advisory through noon. An extra lay would be appropriate!

Despite a wealth of sunshine Thursday temperatures will struggle to warm during the day and highs will likely range from the single digits NW to the low teens in the SE (coldest where snow cover is deepest).

Thursday night promises to be very cold with lows potentially reaching 20 below in some of the colder valley locations in the NW where snow is deep and light winds allow cold air drainage. Both the EURO and GFS are underdoing snow cover near and just east of the Mississippi. I suspect that is why they show lows so much warmer in that part of my area. I think the numbers could be significantly colder by as much as 5-10 degrees in spots. We shall see. However, it turns out it will be plenty cold but with calm winds there will be no wind chill issues to deal with.

After another very fresh day Friday (highs single digits NW to upper teens SE), readings will return to more seasonal

levels Saturday and Sunday. That's the period when 3 disturbances impact the central Midwest. The first early Saturday morning is nothing more than a nuisance bringing with it a brief period of light snow or flurries. A few spots north of I-80 might see a dusting but that should be the worst of it.

Behind that a clipper zips southeast through the region late Saturday night and early Sunday. There should be a window for accumulating snow in some part of my area but that location remains uncertain. The EURO is most impactful over my region laying down a 1-3"+ band of snow focused on the NE half of the area.

The GFS is noticeably further north with its snow amounts.

The GEM is the furthest south with its depiction of snow totals.

Needless to say there are issues to be resolved with this system and another 24 hours should bring better data into the model grids. That said, the EURO is a nice compromise for now and that is the way I'm currently leaning.

A third clipper (the strongest of the bunch), has recently trended on most of the major models to pass just north of the region. Not only does that take accumulating snow out of the area, it should allow a healthy pop of warm advection and a mild day Monday. The EURO now has highs above freezing up to the Minnesota border in NE Iowa and SW Wisconsin.

That does not last long though as gusty winds and sharply colder air surges quickly back in Monday night with the passage of the clipper. Come Tuesday morning the EURO shows lows potentially below zero once again in the NW half of the region. Rest assured wind chills will be far lower than that.

Well, that's about all I have in me for this post. Stay warm and snuggly and by all means, roll weather...TS

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