What is your opinion on climate change?

This isn't a thread for people to bash other people or tell them they're right or wrong. Please do respond civilly and offer constructive criticism.

Our opinions don't matter all that much in the climate change debate, but sometimes it's nice to preach your sermon on a soapbox without having to shout over the crowd. Take your time and lay out your beliefs and opinions on various climate issues (And please keep it to the science and not the politics).

Two severe winters

I heard Joe Bastardi comment recently that the winter of 1995/96 was not as severe as people think it was. For much of the nation, this is true; but for the people of northern Minnesota and North Dakota, both 1995/96 and 1996/97 were two of the most severe winters on record, surpassing blockbusters like 1978/79 when you factor in the amount of snow that felt, how early winter began, and just how long it stuck around.

Wildlife populations plummeted. The pronghorn population of North Dakota fell 75% over the winter of 1996/97.

Here in Minnesota, deep snow in both winters killed thousands of deer even as they grouped together and hovered around rural farmsteads and inside cities and towns hoping the humans would feed them.

An unusual snowfall in September was a harbinger of things to come.

By late October, winter was well on its way. We saw snowfalls on the 24th, 29th, and 31st of October leading to an accumulatd snow that lasted from the 29th of October until the 24th of April, making it the longest continuous snowcover of any winter before or since.

The first storm struck on the 3rd of November bringing several inches of snow and sending temps below zero, about 30˚F below normal, the next morning.

After that a series of clippers and another blizzard in late November kept that month one of the coldest Novembers on record.

That winter we saw 10 significant winter storms and temperatures that plummeted below -45˚F on 5 different nights.

While we saw largely normal weather from February 10th through the end of the month, a blizzard at month's end sent temps plummeting for the beginning of March. Not only did March come in like a lion, but it left like one too... and it was a lion all the way through. The month of March was 11˚F below normal which effectively halted any thawing process that usually occurs throughout the month (as average highs rise from 26-44 throughout the month).

April came in like a lion as well with another significant snow storm. At the beginning of April when the last remnants of snow are usually melting away, we had 30" of powdery snow on the ground. April 1996 was 10˚F below average and the month was more March-like than April like. Only 2 days at midmonth were above normal another system on the 26th of April pushed temps right back into the teens again.

That spring was the latest spring ice breakup on record for most northern Minnesota lakes with only 1950 coming close.

The winter of 1996/97 was more focused on North Dakota. But like the winter before, it got off to a very early start with heavy snows in mid and late November.

December was nasty as well with many significant snowfalls and a nasty windstorm on New Years Eve that brought temperatures of below -30˚F the few days before to over 40˚F a few days later. This all turned around again with a blizzard that saw temps plummet again. The worst Arctic cold came in late January with temps falling to -40˚F on two successive mornings. January also saw plenty of snow so that many regions had drifts that covered their houses in the open areas of western Minnesota.

The snow was so bad in North Dakota and western Minnesota that schools were canceled for weeks at a time.. not only because the roads were completely impassable, but many people couldn't get out of their homes.

By February when things began to calm down and the numbness of our minds began to thaw, our focuses turned towards the obvious coming flood threat. The Red River flood in 1996 was one of the worst on record and this winter had been much snowier in the Red River Valley. The worst possible scenario would be for more snow to pile up and then melt all at once.

And that's exactly what it did. In early March, another storm hit dumping several inches of snow and bringing settled snowpacks to nearly 4 feet in regions that rarely see over a foot on the ground at a time.

You have to consider that the Red River Valley of Minnesota and North Dakota is one of the flattest regions on earth. When the ground is frozen solid and you melt 4 feet of snow (or an equivalent 4-5" of water) plus whatever rainfall you might receive, it's like getting a 6-7" rainfall on a giant state-sized, flat, asphalt parking lot.

You can imagine the results would be devastating.

By late March after more snow had fallen, the big thaw set in. Temperatures, after barely having thawed throughout the entire winter, shot into the 50s with sunny skies for a week straight. Nearly 4 feet of snow melted between March 27th and April 3rd, 1997.

Area tributaries flooded so fast people didn't have any time to prepare. Small towns like Breckenridge, Minnesota saw record floods that swallowed their entire towns. The Red River of the North, usually a rather small river, maybe 50 feet wide, was over 18 MILES wide in places.

Overland flooding on the flat farm fields turned the entire valley into a massive inland sea, not unlike the massive Lake Agassiz that created the valley thousands of years ago.








While the tributaries that feed the Red (which is a liberal term here... more like the entire landmass that turned into a sea and slowly just floated towards the Red) were breaking records, a massive storm system moved in on April 6th-8th..

It dumped over 2 inches of rain over the region before dumping over a foot of snow and sending temperatures below 0˚F. Everything froze solid. People couldn't even evacuate from their homes.

The National Guard was left rescuing people by helicopter and hovercraft.

After the the thaw resumed, all the water gushed into the Red. Since the river flows north and follows the spring thaw, the flood will just tend to get bigger and bigger and bigger the further down river you go. It did its worst in Grand Forks, ND.

Even after emergency crews worked around the clock with area residents to raise the levies and dikes, it was no good. The Red River, nearly 4 feet higher than it had ever been, broke through the dikes and flooded nearly the entire city of 50,000 residents. Only a couple days later, a transformer caught fire and a large swath of the historic downtown burned to the ground. In one of Mother Nature's cruelest ironies, the fire fighters were helpless to do anything to stop it because of the mud filled flood waters surrounding the buildings.

It was a harsh winter for wildlife and for the people that live in the region. But Grand Forks learned its lesson. It immediately began ambitious planning and subsequently rebuilt portions of the city. They removed hundreds of homes that were closest to the river, turning it into park land with lots of trees that diffuse and slow the water, reducing wear on the dikes, which were built to a height of 60 feet, 5 feet above the record crest which can easily be expanded a further several feet with minimal effort.

Since 1997, despite two significant floods in 2006 and 2009 that were both top 10 events, the city was high and dry.

Fargo, North Dakota's largest city has recently begun talking about following Grand Forks in raising its dikes after the river rose to record high levels, shattering the 102 year old records in spring 2009.

1877/78 Super El Niņo

Here is an excellent writeup from the University of Minnesota Climate division on what remains the warmest winter on record in the period of record (though modern records are considered to be after 1891... so this one is not often cited).

http://climate.umn.edu/doc/journal/wint77_78.html

Also below is a graph showing the extreme warmth that began in November and lasted through April.

http://home.att.net/~minn_climo/MSP7778.gif

Another strong El Niņo in 1888/89 also meant a warm winter, though that winter was only way above average... not sizzling.

It should be pointed out that like the the super El Niņo of 1997/98, the following winters of both the 1877/78 and 1888/89 events were quite warm.

When you warm the ocean that much, it has residual effects for years to come.

Teleconnections and long range forecasting

By looking at the relationships between ENSO and the various teleconnections... if you have an idea where they are headed for the winter, it becomes very easy to forecast what the winter will be like.

La Niņas, especially stronger ones, favor the development of a positive Arctic Oscillation, especially earlier in the winter, along with a negative Pacific/North American pattern which means lower heights in western Canada and the NW quarter of the U.S. with higher heights in the southeast (a southeast ridge). The result is the coldest weather int he U.S. occurring in Washington, Montana, the Dakotas, and Minnesota with the warmest weather the further southeast you go.

During Autumn in a classic La Niņa setup, you see warmer than average conditions across all of the U.S. except the immedate west coast. The polar jet, stronger than average, is whipping around the globe in a zonal pattern, slamming storm after storm into the Pacific Northwest. This results in very heavy snows for the Cascades. By the time these storms move east, however, they are moisture starved and moving so fast that they don't do much.

During the last negative PDO, when La Niņas were more common, you see this in the weather patterns. Here in Minnesota, autumn was warmer.. particularly October. This is because the jetstream is stronger than average, keeping the cold bottled well to the north rather than buckling and sending the cold south.

The relatively higher sun angle and residual energy from the summer keeps us feeling quite pleasant.

Winters, however, tend to be very cold, especially as you progress into mid-late winter and spring. While total snowfall is harder to gauge, the colder than normal temps mean that even with average precip, you'll see more snowfall than normal.

Springs during La Niņa years are very consistently colder than normal, centered usually on March and April. May can go either way.. and La Niņas tend to usually bring hotter than normal and drier than normal summers to Minnesota (1975, 1988, 1999).

El Niņos are exactly the opposite. During El Niņo, the Arctic Oscillation likes to be negative while the PNA likes to be positive. Depending on the strength of the El Niņo and the amount of warmth and moisture it transfers northward from the tropical Pacific, this can mean a nasty, cold winter for the eastern U.S. It very often means warmth and dryness in the northwestern quarter of the U.S. and all of western Canada.

This is not the case throughout the entire winter season, however.

El Niņos, unlike La Niņas which give us benign, pleasant Autumns, tend to dump cold on us early... particularly in October.

This is why, despite every other month having warmed or at least stayed the same since the mid 1970s in Minnesota, October has gotten colder. El Niņos have become more frequent.

On the other hand, with a weaker jet, springtime weather can go either way... but do bias towards warm.. especially in March and April.
Unlike La NIņas which favor warm, dry summers, El Niņos favor cool, wet summers, especially early on. This is not always the case, since El Niņos and La Niņas are rarely strong during early summer... but it seems that the vast majority of very cool Junes have occurred after El Niņo winters.

At the same time, cool summers can follow La Niņa winters and vice versa (1950 was a cold summer with La Niņa conditions while 1987 was a hot summer with El Niņo conditions).

During weaker to moderate El Niņos, the weaker polar jet often buckles and dumps cold air into much of the nation. As time goes on throughout November, this moderates so that by late November, temperatures are consistently above normal. A classic example is 2002/03.. we had a near record cold October followed by an average November and a very warm December.

This is because by the time December rolls around, the El Niņo has kind of used up the cold at its disposal and the Arctic has warmed up. The cold has to rebuild in strength as the U.S. basks in balmy weather.

Despite this, the southern U.S. will often see near normal temps since Arctic air usually isn't present in December anyway and a stronger than normal southern jet stream keeps it cloudy and wet and also cool.

During a weak to moderate El Niņo, December is very warm, followed by either a normal or slightly warmer than normal January, and then a cold February.. though on the whole the Dec.-Feb. period is still above normal. Classic examples? 2006/07, 2002/03, 1994/95, to some extent 1987/88.

During strong El Niņos, the absolute warmth of the tropical Pacific keeps much cold air from getting into the U.S. at all. During strong El Niņos, October and November tend to be near normal, but the warmth usually arrives by Thanksgiving.

During stronger El Niņos, January tends to be the only month with any real winter weather.. and even then the month usually remains above normal for the northern U.S. By February, the warmth returns again, often in a big way. 1997/98, 1986/87, 1982/83 are 3 of the best examples.

Of course these are classic examples. The teleconnections don't always line up like they should with the various ENSO events. Also, the PDO has a huge effect. The positive PDO of the 80s and 90s enhanced El Niņo while it tempered La Niņa. The only true La Niņa to occur during that period was 1988/89.

During the negative PDO of the 50s, 60s, and 70s, some of the nastiest winters were actually El Niņos.. 1977/78, 1968/69, 1965/66.. those were all memorable winters (the earliest for the snow that lasted into May, the 2nd for the constant bombardment of blizzards in December and January, and the latter for the extreme cold and heating fuel shortages in the region).

So, it is tricky to get the winter down right... and I think Joe Bastardi is one of the best when it comes to classifying classic patterns.. things like "Step down winters" like 02/03 that got colder against the means as time went on, or bookends winters like 2005/06, 2000/01, or the mother of all Bookends, 1989/90...

It appears winter 2009/10 will be a pretty classic moderate El Niņo winter in the "bookends" style..

The AO will ensure there is plenty of cold air around to bring down into the U.S. while the positive PNA and EL Niņo will ensure the core of that cold stays east and south.

Northern Minnesota Weather UPDATES

I figured my last thread went horribly off topic, so I'll make this one about the actual weather in my neck of the woods.

Last night was our coldest night of the season so far with a low of -2˚F. Today was a bright, sunny day and we reached 18˚F.. so all in all, we were a few degrees below average.

Today's models are predicting that the cold weather should stick around through the foreseeable future with the core of the cold centered around the middle of next week with lows in the single digits below 0˚F and highs in the single digits above.

Since we have almost no snow on the ground, the temperatures cannot really drop very far.. and with almost no snow in the forecast for the next two weeks, it will continue to be that way.

With the lack of snow, the second the pattern changes, temperatures will shoot well above normal and the negative anomaly buildups happening right now will be erased in half the time.

Either way, the pattern is pretty wild. Even the blowtorch that the GFS sees about 11 days down the road will mostly be an 850mb event with surface temps only reaching the freezing mark or so here. Still, with 850mb temps at 45˚F and the surface at 28˚F... that can only mean one thing with the precip from that storm.

But i shouldn't get my hopes up. Like every other potential for snowfall or weather of any consequence so far this winter, it has either not developed or passed north of us.