Elsewhere in Weather News: October 6th, 2012

Record Early Snowstorm Hits Northern States

The same powerful low pressure system that brought the first significant snowfall of the season to Southern Manitoba dropped copious amounts of snow south of the border. A surface low pressure system that was moving in a north-easterly fashion combined with a deepening upper low through the area resulted in a record-breaking early winter storm this past week in North Dakota and Minnesota.

Visible satellite

Image of visible satellite taken on Friday afternoon. Large upper low is located in NW Ontario with jet stream in pink and cyan circled area the hardest hit areas. (Image source: COD)

Impressive snowfall totals were recorded in Northern Minnesota and North Dakota in the wake of the storm. Numerous cars were spotted in the ditches and tractor-trailers jackknifed in Northern Minnesota on Friday, due to treacherous road conditions. Around 3,000 people were out of power in the two states on Friday afternoon in the hardest hit areas. Woodridge, MB to Thief River Falls, MN received the heaviest bands of snow. Below lists some of the impressive amounts of snow accumulation recorded in Minnesota and North Dakota, as per reported by the National Weather Service:

  • Badger, MN (30 minutes south of Piney, MB): 30-36cm
  • Roseau, MN: 18cm
  • Grand Forks, ND: 9cm – A record for largest amount of snow to fall this early in the year (old record: 5cm)
  • International Falls, MN: 4cm – Also a record for the largest amount of snow to fall this early in the year (old record: 1.5cm)

(The remainder of the reports as of 3pm, Friday afternoon can be seen at http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=fgf&storyid=87914&source=0)

This snowfall brings to a close (for now) the extreme fire danger in North Dakota and Minnesota whose conditions were similar to Southern Manitoba – extremely dry and windy. The Karlstad fire in Minnesota on October 3rd was fanned by severe 65km/h winds and drought conditions. In total, 31 buildings were destroyed; thankfully, no one was hurt.


Picture of the damage in Karlstad. (Source: MPL/Nathaniel Minor)

As the low pressure system continues to move further north-east, areas in Northern Ontario such as Timmins and Geraldton will experience their first snowfall of the year.

Improving Weather, But Remaining Cool

The effects from the low pressure system responsible for yesterday’s dump of snow over southeastern Manitoba will linger for one more day before moving off and returning us to sunnier skies.

Snow piles up on the Trans-Canada Highway

Snow resulted in the Trans-Canada highway being reduced to one lane each direction as numerous cars hit the ditch due to icy road conditions.

We’ll see widespread flurries over the Red River Valley today, however the potential exists for significant accumulation in the lee of Lake Manitoba and Lake Winnipeg. Brisk northerly winds, combined with strong instability over the still-warm lakes, will advect fairly strong lake-effect snow bands southwards off the lakes. These will be long, narrow features that will depend significantly on the wind direction. Currently, it appears that the heaviest flurry activity will be along a N-S line near Portage la Prairie, and another N-S line just east of Winnipeg. Should the winds back to a little more NE than northerly, Winnipeg could certainly see some of the action. Most locations that see just general flurry activity will likely receive 2-4cm of snow; how much actually stays on the ground will be highly dependent on what the pre-existing ground cover is like. Areas that have mostly bare ground right now should have enough heat coming off it to melt most of the new snow that falls. Areas in the eastern half of the Red River Valley, which already have had 10-20cm of snow fall, will definitely see the snow slowly pile up on top of the existing stuff. For those that get caught for any significant period of time under the lake-effect bands of snow, 5-10cm is certainly possible, if not even a bit more than that.

Winds will remain fairly strong today out of the north at around 40km/h with gusts to about 60km/h. Temperatures will struggle through the day, with plenty of cloud and cold advection occurring; we’ll probably only see 2°C or so..perhaps up to 3°C.

Things begin to improve tonight; winds will die down this evening and the cloud cover will start to clear as a ridge pushes into southern Manitoba from the northwest. Temperatures will hover around 0°C until the clouds break up, then temperatures will drop to about -5°C for the remainder of the night.

For Saturday, we’ll see sunny skies over southern Manitoba as we sit under the influence of an arctic ridge. Temperatures will only climb to about 7°C, so it will remain fairly chilly despite the sunshine.

On Sunday we’ll see increasing cloud throughout the day and a high of about 8°C. The cloud is coming ahead of a low pressure system dropping southwards from the Arctic along a reinforcing blast of cooler air. Showers will push into portions of the northern Red River Valley overnight, with the more organized precipitation looking to fall over the northern and eastern Red River Valley into the Whiteshell on Monday. Currently, it looks as though this precipitation will fall as rain.

Major Cool Down Begins

A significant change in the weather is underway today as Arctic air blasts southwards, pushing out the pleasant, above normal temperatures we’ve had lately and replacing it with cloudy, cool, windy weather. I hope you enjoyed the last few days, because you probably won’t enjoy the next few.

850mb Temperatures from the GFS

850mb temperatures valid this morning from the GFS model. Warm and cold fronts are depicted.

A cold front, tied to a powerful low pressure system moving through central Manitoba, swept across the Red River Valley overnight, ushering out the warmer temperatures aloft that have given us pleasant temperatures the past few days. In it’s wake is a dramatically different pattern than we’ve seen lately.

Upper troughing will dominate the Prairies as a secondary low, currently spinning up over Montana/Wyoming tracks eastwards and pulls more cold air southwards. This will establish us into a much cooler pattern where cooler, Arctic air is entrenched over the region and it’s significantly harder for us to get those nice warm breaks.

Today we’ll see winds begin to pick up out of the north as temperatures climb to only around 13°C. We’ll get cloudier as the day goes on, and by the late afternoon into the evening some showers will push into the southern regions of the Red River Valley. Further north, we’ll see a chance of showers, however it will be more difficult for any organized precipitation to develop over the northern Red River Valley.

As the aforementioned US low tracks through South Dakota, winds will shift to the north-northeast over the RRV, which when combined with the cooler air being dragged southwards, will bring lake-effect showers into the central Red River Valley. Current model solutions hint that Winnipeg may be in the path of these, however, as usual, the exact wind direction will be crucial in determining where the showers will fall. Temperatures will drop to around +3°C tonight.

Thursday will be a cool day, with northerly winds persisting, cloudy skies and a high of only 7 or 8°C. Lake effect showers will persist in the lee of the lakes, and scattered showers will likely be found throughout the entire Red River Valley. Cold air continues to pour southwards and we’ll drop to near 0°C. Precipitation is…complicated for Thursday night. The GEM-GLB & GFS models are forecasting only around 5mm of rain for Thursday evening over SE Manitoba, including the Steinbach region. Other models, such as the NAM, have a much worse forecast. The NAM spins up the low over the states into a very powerful storm system, which taps into some Gulf moisture over the east-central States and lifts it northwest and slams it into a deformation zone oriented north-south over the Red River Valley. In this outcome, 1-2 inches of precipitation is forecast to fall, some as rain, however much of it as snow. Should we believe the NAM, it would result in many communities east of the Red River waking to find over a foot of snow on the ground! Ensemble forecasts suggest that this is an outlier; most solutions favour a quicker track to the low with less precipitation over the Red River Valley. We’ll keep a close eye on this as it develops, but you should be prepared for the potential for poor travelling conditions on Friday.

Things calm down on Friday as this system leaves the region and we’ll be left with cloudy skies and a high around 10°C. Things look to improve a little bit for the weekend (e.g. we may see the sun), but temperatures will remain locked in the high single digits to low teens as cold, arctic air remains entrenched over the region.

Springtime Low to Bring Cooler Weather This Weekend

A low pressure system tracking through western and central Manitoba will bring unsettled weather, cooler temperatures and windy conditions to the Red River Valley this weekend…but not before one more beautiful day.

Forecast surface temperatures

Forecast surface temperatures for mid-afternoon today.

Conditions will be fairly uniform across the Red River Valley today with plenty of sunshine, highs near 20°C and a stiff southerly wind blowing at 40 to 50km/h. It’s a fitting end to another simply beautiful, and above normal with regards to the temperature, week. Tonight, a low pressure system will eject out of southeast Saskatchewan across Parkland Manitoba and into the Interlake. Associated with this low is a very strong 40kt low-level jet (LLJ), however a lack of moisture and unimpressive mid-level lapse rates should erase any concerns (or hopes) of nocturnal convection.

A cold front will sweep across the Red River Valley on Saturday morning, bringing a chance of showers to most regions; indications are that areas east of the Red River will see a greater chance of a shower or two than areas west. After the passage of the cold front, the entire RRV will be left with a fairly strong westerly wind and cloudy skies.

Accumulated Precipitation

Total accumulated precipitation from 00Z Friday to 00Z Monday. This shows the relative lack of precipitation over SW Manitoba and the RRV; a stark contrast to the copious amounts of precipitation that are forecast over Eastern Saskatchewan and Western Manitoba.

The wrap-around precipitation will begin to move into the RRV on Saturday night, coincident with colder air diving southwards on the backside of the low. Current indications are that the precipitation will fall as snow and that the northern half of the RRV has a much greater chance of seeing flurries than the southern half. The low continues to lift NE through the day Sunday, pulling the wrap-around northwards with it and out of the RRV. It will be a struggle between the main area of lift pulling north and remnant moisture and instability in the cooler air left in the RRV. Most areas in the RRV will likely see a little bit of snow on Sunday, however the only areas that might accumulate a cm or two would be north of Morris.

All in all, we’re being spared with this system, as large amounts of precipitation are forecast from the Moose Jaw/Regina, SK region along a line NE to Swan River and The Pas. The GEMGLB is currently painting up to 75mm of precipitation, which if that were to all fall as snow would likely end up as 1-2 feet of the white stuff. We’ll see how much actually falls, though, as the GEMGLB can have problems with convective feedback in situations where embedded elevated convection is a possibility along a warm front. Anyone planning to travel to Saskatchewan today or on the weekend should make sure they check road conditions and weather forecasts for cities/towns along their route before they leave.

After that things clear out for the start of next week and our temperatures rebound back into the low teens by midweek. Things are looking like we’ll have continued sun and warm temperatures into next weekend as well.