Slowly Improving Weather in Store

The weather will slowly improve over the next couple days as some warm air begins to slowly push across the Prairies.

3hr. Cumulative Precipitation for late this afternoon

3hr. cumulative precipitation from the RDPS for late this afternoon.

Today will remain mostly cloudy across Southern Manitoba with two main features to pay attention to. The first feature is a low pressure system that will slide from Southern Saskatchewan into North Dakota, bringing with it a chance of showers through southwest Manitoba through the morning and into the early afternoon. The second feature will be a trough slumping southwards through the Interlake into the Whiteshell. The southern extent of this trough will move through the Red River Valley in the late afternoon and evening, and as it enters the area, a few scattered convective showers or flurries will develop along it and move through the region. Whether we see rain or snow will depend on the exact timing of the system and what the temperature is; either way, accumulations will fairly insignificant and the showers likely won’t be widespread. Daytime highs will be around 6°C this afternoon.

After these systems pass, we’ll see skies slowly clear out overnight as temperatures drop to around the -3°C mark. A ridge of high pressure begins working it’s way into Manitoba; skies will remain mainly sunny as temperatures slowly climb. Tomorrow we should see daytime highs around 9°C through the Red River Valley, and increasing up to around 11°C for Friday. We’ll see a mix of sun and clouds on Friday as a weak system brings some cloud through the Red River Valley as it passes through central Manitoba.

The weekend looks relatively average, with no indications so far that any significant precipitation events are in store for us over the next week.

Gloomy Thanksgiving Monday

This Thanksgiving will be nothing like last year’s (which featured temperatures in the twenties), as rain and wet snow make for a rather miserable holiday Monday.

Total precipitation accumulation for Monday's system

The GEM model shows generally 10-20mm of precipitation over Southern Manitoba

A low pressure system sliding south-eastward through Manitoba on Monday will be responsible for the precipitation, with rain beginning to move into Southern Manitoba early Monday morning. Temperatures on Monday will be cool, but generally not cold enough for snow with values hovering in the mid single digits during the daytime. By evening there will be a changeover to snow in some areas, mainly portions of Western Manitoba, as colder air is pulled down from the north. Areas in the Red River Valley can expect a bit of wet snow late Monday evening into the overnight period, but with surface temperatures remaining above zero, no notable accumulation is expected. Total precipitation accumulations will generally range from 10 to 20mm across Southern Manitoba by early Tuesday.

Unfortunately, conditions will improve little for Tuesday. It will be a chilly start to the work-week as cold air pulled down by the previous day’s low pressure system will not allow temperatures to climb much higher than the mid single digits at best. Monday’s low pressure system will have departed by Tuesday morning, so no more significant precipitation is expected (save for perhaps a few scattered showers or flurries). At this point models keep us in the single digits for Wednesday as well, so even normal weather will continue to elude us.

The late week period looks to remain fairly miserable, with temperatures staying stuck in the single digits. No more significant precipitation is expected later this week.

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.