Sunday, January 30, 2011

Dry week ahead with warming trend.. next snow threat looms for weekend..

A large ridge of Arctic high pressure over the Prairies will bring dry and cold weather over southern Manitoba to start the work week.. allowing some time to recover from Friday's wintery wallop. This high pressure ridge will dive southward into the US during the upcoming week, bringing unseasonably cold weather to the southern US Plains while helping to fuel a significant winter storm system that will affect a large part of the US midwest, Ohio valley and New England, as well as southern Ontario by mid week. Meanwhile, a return flow of milder Pacific air will spread over the western Prairies during the week, bringing a noticeable warming trend into southern MB for the middle to latter part of the week. The next threat of snow for Winnipeg and southern MB will be next weekend as another Alberta clipper tracks across southern MB bringing some snow, and a return to colder weather for next week.

It's too early to say how much snow the weekend's clipper will bring to the Red River valley.. these systems have had a history of bringing 5-10 cm to southern MB although Friday's more intense system brought 10-20 cm. These systems have helped to produce another month of above average snowfall in Winnipeg, with 44 cm recorded during the month, some 20 cm above normal. This has put the seasonal snowfall since Nov 1st to 115 cm in the city.. which is already an entire winter's worth of snow... with 2-3 months of additional snowfall to come. This winter is on pace to be the snowiest winter in Winnipeg since the winter of 1996-97 when 205 cm was recorded prior to the great Red River flood in the spring of 1997.

Thursday, January 27, 2011

Alberta clipper to bring more snow.. risk of freezing rain.. to southern Manitoba tonight into Friday

An intensifying Alberta clipper storm system will track into central Manitoba overnight and move across the Red River valley Friday bringing another round of snow to southern Manitoba. Snow from this system is expected to move into The Pas area this evening then spread southeastward through the Interlake areas into southern Manitoba tonight. Snow will become moderate to heavy at times with 5 to 10 cm likely across the Red River valley by Friday afternoon, and 10-15 cm possible through the Interlake areas. An area of freezing rain is also possible over southwest Manitoba this evening and overnight as the clipper system brings in some warmer air aloft. On Friday the clipper will track into the Dakotas with northerly winds behind it dragging colder air in by Friday evening into Friday night. This will lead to colder but sunnier weather for the weekend.

UPDATE: This storm system brought heavy snow to Winnipeg and the northern Red River valley, especially between 9 am and noon. I recorded 3.6 cm of snow between midnight and 7 am, with another 11 cm between 7 am and 1 pm. Snow was especially heavy around 11 am when visibility dropped to 100 metres in heavy snow. Click here for a 24hr time lapse sequence of this day, and note the near zero visibility about half way into the video .

Saturday, January 22, 2011

Frigid start to the weekend.. moderating trend begins tomorrow with milder weather next week

It's another frigid morning over southern Manitoba with temperatures dipping to -35C or colder in many areas of the Red River valley and SE Manitoba. Winnipeg airport dropped to -35C earlier this morning, the coldest reading of the winter so far. Arctic high pressure over southern Manitoba will maintain sunny and very cold temperatures today but luckily winds will be light so windchill won't add noticeably to the cold. The good news is that a moderating trend will begin tomorrow as a warm frontal boundary over Saskatchewan starts pushing eastward. A series of Alberta clippers over the next few days will gradually push this boundary across Manitoba, allowing milder Pacific air over the western Prairies to start spilling into southern Manitoba.

The transition to this milder weather will begin overnight through Sunday as a clipper system starts pushing cloud and some snow into southern Manitoba along with increasing south winds. Temperatures will be on the rise overnight through Sunday, with temperatures of zero to -5C expected west of the Red River valley by late Sunday including Portage and Brandon. The milder air will be slower to arrive in Winnipeg and the Red River valley with temperatures rising to -7 to -10C by Sunday evening, but accompanied by brisk southerly winds gusting to 50 km/h which will add a noticeable wind chill along with some local blowing and drifting snow. Milder temperatures will push into the Red River valley early next week, with highs up to -3c possible Tuesday into Thursday. Colder weather looks to return by next weekend.

Thursday, January 20, 2011

January thaw spreads over Alberta while Manitoba shivers

A surging mass of mild Pacific air will be spilling over the Rockies into Alberta and western SK over the next few days, while Manitoba remains entrenched in cold Arctic air. Temperatures will rise above zero over much of southern and central Alberta today through the weekend, while temperatures of -20 to -30 prevail over the eastern Prairies. The dividing line between these two distinct airmasses will set up from northern Alberta into western North Dakota, with occasional clippers moving along this boundary bringing bouts of snow that will clip southern MB from time to time, especially over southwest sections. Long range guidance is hinting that this dividing line will shift east into southern MB next week with moderating temperatures and a chance of snow.

In the meantime, be prepared for very cold conditions today into tonight over southern Manitoba as an Arctic ridge builds in. Temperatures this afternoon in Winnipeg will struggle to the -23C mark but the good news is that winds will be dropping off as the ridge builds in, so windchill won't be a significant issue this afternoon into this evening. Temperatures however will plummet into the low -30s this evening as the ridge moves over the red River valley (note this ridge brought temperatures of -35 to -40C this morning over western MB and eastern SK) The coldest temperatures will be this evening then look for rising temperatures overnight as clouds move in and winds pick up from the south. Those winds however will bring increasing wind chills once again, with values near -40 overnight into early Friday morning.

Thursday, January 13, 2011

A little snow today.. a little more tomorrow..

A weak clipper system moving through the Dakotas brought a general 2-5 cm of snow across southern Manitoba last night into this morning. Snow will taper off during the day today with another 1-3 cm possible before it ends.

Snowfall reports around southern Manitoba as of 8 am this morning with snowdepth on the ground in cm /xx/.

Rivers....... 7 cm... /60/
Rossburn .... 5 cm... /56/
Carman....... 4 cm... /41/
Winkler ..... 4 cm... /34/
Miami........ 5 cm... /27/
Brandon ...... 3 cm... /47/
Portage...... 3-6 cm... /33/
Winnipeg ..... 3-4 cm... /26/
Oakbank ...... 2 cm... /30/
Rennie ....... 2 cm... /38/
Pinawa ....... 2 cm... /37/

Another clipper will bring more snow Friday..with potential for 5-10 cm over southern MB. Timing on this one will be a little different than today's system with snow moving into Winnipeg/RRV Friday morning after the morning rush hour.. becoming moderate at times by midday through mid afternoon before tapering off in the evening. Winds during the event will be light so blowing and drifting snow shouldn't be a problem during the day.. ..however the winds do pick up from the north in the evening as the snow is tapering off so some blowing and drifting snow will likely develop in open areas Friday evening into Friday night. Overall amounts for Winnipeg look to be around 5-8 cm cm with Friday's system with the bulk of the snow falling between noon and 6 pm. Friday morning commute should be OK but evening commute will be slower than usual..

Tuesday, January 11, 2011

2010 warmest year on record in Canada (since national records began in 1948)

2010 ended up as the warmest year on record in Canada since national records began in 1948, according to the latest climate bulletin released from Environment Canada. On a national basis, 2010 finished with a mean annual temperature that was 3.0C above normal, surpassing the previous warmest year of 1998 which was 2.5C above normal (normal as defined by 1951-80 average - see table of ranked years) The bulk of the warmth over the past year has largely been concentrated over the Arctic, especially the eastern Arctic which has seen some exceptionally warm weather for 14 consecutive months now. In particular, Iqaluit on Baffin Island finished with its warmest December on record, a phenomenal 14C above normal, capping off its warmest year ever recorded. 5 of the top 10 warmest years in Canada have occured in the past decade.

Precipitation wise.. the country ranked near normal for precipitaion in 2010, posting a national average that was just 0.4% above normal. The notable exception however was over the Prairies, which recorded its wettest year on record (since 1948), beating the previous wettest year of 1951. (see regional precipitation table)

In Winnipeg, 2010 ended up as the second wettest year of all time (722 mm total precip) , as well as the 8th warmest year on record (annual mean temperature of +4.1C, about 1.5C above normal) Records in Winnipeg began in 1872.

Sunday, January 02, 2011

Cold and quiet start to the New Year

It's a cold and quiet start to the new year as Arctic high pressure builds over the Prairies. This ridge will give mainly sunny conditions and seasonably cold temperatures over the next couple of days. Luckily, winds will be light today and Monday so windchill should not be an issue. A weak clipper system will bring a chance of some light snow to southern MB by Wednesday into Thursday followed by clearing and cold conditions for the end of the week into the weekend. Long range guidance is indicating a spell of below normal temperatures next week with little in the way of major storm systems affecting southern MB. Mid winter weather is here.