Sunday, December 25, 2011

A rare brown Christmas for southern RRV, southwest MB, North Dakota..

It was a rare brown Christmas for portions of southern MB and much of North Dakota this year as the spell of unseasonably mild and dry weather that has persisted much of December continued through the Christmas holiday weekend. Much of the southern and western Red River valley (incl Emerson (above left), Morden and Carman) , southwest MB (Pilot Mound to Melita) and much of North Dakota (Grand Forks, right) were snowfree Christmas morning.. the first time this has happened since at least 1997. In Winnipeg, there was a little more snow around with about 2 cm on the ground Christmas day (an official "white" Christmas here) although most large open fields in and around the city had little or no snow cover (see webcam shots from south Winnipeg and Sanford). This is the lowest Christmas day snowdepth in Winnipeg since 1997 when a trace was officially observed at Winnipeg airport during a strong El Nino winter.

Satellite photos (left) show the minimal snow cover extent across southern MB and North Dakota, with little snow evident over the southern and western Red River valley and North Dakota and Minnesota.. which normally would be covered in white by this time of year. Click here for an explanation on this winter's slow start. Whether it was brown, white or green.. here's hoping everyone had a happy and healthy Christmas! All the best in 2012!

Wednesday, December 21, 2011

Staying mild and storm free through Christmas..

The above normal temperatures and tranquil weather of December is forecast to continue through the upcoming Christmas holiday weekend, with little in the way of major weather systems to disrupt holiday travel plans across southern MB. Temperatures are expected to remain 5 to 10 degrees above normal through early next week as mild Pacific airmasses periodically sweep across the Prairies keeping cold Arctic intrusions at bay. In fact, above freezing temperatures are forecast for Christmas Day into Boxing Day as another push of Pacific air sweeps in over the holidays. This will likely mean a brown Christmas for portions of southern MB this year, especially towards the US border into North Dakota (see webcam page). For Winnipeg, we will likely end up with whatever we have now.. a meager coating of about 2 or 3 cm with no significant snowfall expected between now and Christmas. The longer range outlook calls for above normal temperatures to continue through the end of December, with no signs yet of a major pattern shift to colder and snowier weather over the southern Prairies. For you snowlovers out there, have faith though.. technically, winter is just starting! (winter solstice arrives tonight at 11:30 pm CST)

Tuesday, December 20, 2011

Christmas Day snow stats for Winnipeg

Here are some Winnipeg Christmas snow stats looking at how often Winnipeg has had a White Christmas. These figures are based on snow on the ground measurements from Winnipeg airport from 1955-2002, and Charleswood from 2003-present. (Note that official snow on ground measurements start in 1955 at Winnipeg airport)

Christmas day snow on ground stats (Winnipeg since 1955)

Least snow on ground....... TR (1997) *
Most snow on ground......... 80 cm (1955)
Average snow on ground.... 16 cm
* Prior to 1955, there have been at least 3 Christmases with no snow on the ground in Winnipeg: 1939, 1913, and 1877

Last 10 Christmases..

2010 ......... 23 cm
2009 ......... 10 cm
2008 ......... 24 cm
2007 ......... 28 cm
2006 ......... 11 cm
2005 ......... 14 cm
2004 ........... 8 cm
2003 ........... 4 cm
2002 .......... 12 cm
2001 .......... 12 cm
2000 .......... 30 cm

Since 1955, there have been 7 Christmases in Winnipeg with 3 cm or less on the ground. There have been 6 Christmases with 30 cm or more on the ground (last one was Dec 2000). This year it looks like we'll end up with 2 or 3 cm on the ground Christmas Day, barring any unexpected snowfalls between now and Sunday. That will be the least amount of snow on Christmas day in Winnipeg since 1997 (although we had a paltry 4 cm in 2003).

Prior to 1955, there have been 3 Christmases documented in Winnipeg with no snow on the ground, although these are not part of the official climate record. They were 1939, 1913 and 1877. (Click here for a Winnipeg Tribune article on the rare "green" Christmas in 1939 in Winnipeg that year.) There was also reference made that in Dec 1834, the first snow of the season in Winnipeg fell on Dec 28th.. so it's possible Dec 1834 was also a brown Christmas (but then, we don't know what they considered the first significant snow back in 1834)

Thursday, December 15, 2011

Where's the snow? Snow drought continues over southern MB..

The lack of snow this month in Winnipeg and southern MB is becoming quite evident with barely any snow on the ground just 10 days before Christmas. In Winnipeg, only 0.8 cm of snow has fallen so far this month as of the 15th, with only a couple of cm still on the ground. Parts of the southern Red River valley are actually snow free as is much of eastern North Dakota.. raising the prospect of a possible brown (or "green") Christmas this year with little in the way of significant snowfalls expected over the next week or so.

In Winnipeg, the 0.8 cm of snow so far this month is well below the monthly average of 19.8 cm.. and is on pace to be one of the least snowiest Decembers on record if the snow drought continues. The last December in Winnipeg with less than 10 cm of snow for the month was December 1997 when only 7.3 cm fell during a strong El Nino winter. Below is a list of Winnipeg's top 10 least snowy Decembers since records began in 1872.

Top 10 least snowy Decembers in Winnipeg (since 1872)

1. 1877 ............ 0.5 cm (warmest December and winter on record)
2. 1892 ............ 1.3 cm
3. 1931 ............ 2.0 cm
4. 1899 ............ 2.8 cm
5. 1954 ............ 3.3 cm
6. 1939 ............ 3.6 cm (Green Christmas)
7. 1907 ............ 4.6 cm
8. 1896 ............ 4.8 cm
9. 1959 ............ 5.3 cm
10. 1957 .......... 6.1 cm

As can be seen from the table, there have been several Decembers with meager snowfall.. so we still have a ways to go to enter the top 10. It doesn't take much to get a snowfall of 5-10 cm or more in December, so by no means is it a sure thing. But the way things have been going, the potential is there for a top 10 finish.

So what does a lack of snow in December mean the rest of the winter as far as snowfall is concerned? Not much really. Of the top 10 least snowy Decembers, about half had above normal snowfall the rest of the winter, and half had below normal snowfall. So there really isn't a correlation between December snowfall and the rest of the winter. So if you're itching for some of the white stuff, take heed.. we still have a lot of winter left!

Wednesday, December 14, 2011

Freezing drizzle leaves icy conditions in Winnipeg/southern MB...

Freezing drizzle was observed across Winnipeg and much of southern MB today as a moist mild airmass brought extensive low cloud and misty conditions across a large part of the Northern plains and eastern Prairies. The image here is what the Bishop Grandin webcam looked like this evening in the south part of Winnipeg, a result of a coating of freezing drizzle on the webcam lens. Kind of pretty actually.. looks like an impressionist oil painting! Freezing drizzle can sometimes occur in moist stagnant airmasses in the winter when temperatures are close to but below freezing, although it's not as serious as freezing rain which can lead to greater ice accumulations in a shorter time. However, an extended period of freezing drizzle can leave a thin coating of ice on exposed surfaces, with slippery conditions on untreated roads and walkways. Drier and colder conditions are expected overnight into Thursday as brisk northwest winds usher in a colder airmass from the north. Temperatures will return to normal over the next couple of days before another warmup this weekend. Some light flurries are possible from time to time, but overall no significant snowfall is expected over the next week as the snow drought continues over southern MB.

Friday, December 09, 2011

Milder for the weekend.. cooler again next week. Snow continues to evade southern MB..

Cold weather today will give way to milder weather this weekend as a milder Pacific airmass spreads across the Prairies. Temperatures will climb into the minus 2 to minus 5C range over the Red River valley for the weekend, with light winds and partly sunny skies. Cooler air will follow Monday into Tuesday, but temperatures should be close to seasonal averages which are now close to -10C for highs and -20C for lows.

As far as snow is concerned, there is little in the forecast over the next little while. Models continue to show a lack of major weather systems affecting southern MB over the next week to 10 days.. with the exception of a potential storm system passing through Minnesota late next week which may affect parts of southern MB by next Thursday or Friday. Other than that, things look pretty quiet as snow bearing systems mainly bypass us well to the north, or to our southeast. This will come as bad news to snowlovers out there, but will be welcome news to those who aren't as fond of the white stuff. So far, we've had less than 1 cm of snow in December, with only a minor coating still on the ground.