Spring Storm Incoming

A potent storm system is on the way.
A potent storm system is on the way.

A large spring storm will bring the most significant rainfall to the Red River Valley since last October. It will be mainly rain that falls over the next couple days, however higher-terrain areas of Parkland Manitoba will likely see snow feature more predominantly. This system will be fairly long-lasting, too, with precipitation pushing into SW Manitoba this morning and lingering through Friday.

Wednesday

Wednesday
11°C
Increasing cloud.
Wednesday Night
3°C
Rain beginning in the evening. 5-10mm.

The wet weather over the next couple days is being caused by a strong upper-level trough (depicted in the picture at the top of this post) that is pushing inland from the Pacific. This feature will spawn an elongated trough of low pressure with embedded low pressure centres within it that spans all the way from Alberta through Saskatchewan, Manitoba, and southwards to Texas. This large feature will be aided by an upper-level low tracking along the Canadian/US border which will amplify the precipitation through the Canadian Prairies.

So, what will we see? Rain will spread into southwestern Manitoba this morning and slowly – quite slowly, actually – spread eastwards through the day towards the Red River Valley. By the afternoon, rain should push into the western RRV, but likely won’t reach Winnipeg and into the eastern RRV until late this afternoon or into this evening. By the evening, most areas across Southwest and Parkland Manitoba will likely see around 10-20mm of rainfall, with the potential for some localized amounts of 20-25mm.

Rain will continue to push eastwards through the night, bringing fairly steady rain to most areas in Southern Manitoba. Areas in extreme southwestern Manitoba may see things taper off as the main axis of rain begins shifting to the northeast. Another 5-10mm of rain will fall in most places, however in higher elevations of Parkland Manitoba the rain will switch over to snow overnight with 5-10cm of accumulation possible.

Thursday

Thursday
5°C / 0°C
Rain. 10-20mm.

Thursday will see rain tampering off in Southwest Manitoba, but being reinvigorated over the Red River Valley and Interlake by another shot of moisture lifting northwards along the trough line. Here in the RRV around another 5-10mm will fall, however portions of the valley into the Whiteshell may end up seeing 10-15mm if the heavier rain arrives a little earlier.

Storm-total precipitation expected from Wednesday through Friday.
Storm-total precipitation expected from Wednesday through Friday.

Light rain will persist through much of Thursday night and perhaps become mixed with snow as we approach our low temperature of around 1°C. Another 2-5mm of precipitation is expected.

Friday

Friday
5°C / -6°C
A few showers or flurries.

The system will finally begin pushing out of the region on Friday, however an lingering trough will hang back into the province for much of the day, spreading some showers or, at times through the morning, light flurries through the region. Further amounts of precipitation will be minimal – likely less than 2mm.

Things look to clear out for a sunny weekend. Saturday’s high will be below normal, somewhere around 6°C or so, and Sunday will return to a near-normal high in the low teens. The nice weather may be short-lived, though, as weather models are hinting towards the development of a Colorado Low that would impact Southern Manitoba starting Sunday night.

Spring Storm Marks A Return to Form

A storm system pushing through Southern Manitoba tonight will bring snow, rain and everything in between to Southern Manitoba tonight, marking a significant shift in the upper-level flow that will bring seasonal to above seasonal temperatures through the weekend and into next week.

Friday
7°C / +2°C
Increasing cloud. Rain beginning this evening. 10-15mm.

Saturday
10°C / 0°C
Clearing in the afternoon; chance of showers.

Sunday
11°C / 0°C
Mainly sunny. Chance of showers overnight.

First Significant Rain of the Year

Today will be a pleasant day; high temperatures will sit around 6 or 7°C this afternoon with mainly sunny skies giving way to increasing cloudiness this evening. Winds will begin to pick up this afternoon to around 30km/h. The big story, though, is the low pressure system that will track through tonight.

A major low pressure system will begin pushing into Southern Manitoba tonight. This system, marking the transition into a warmer weather pattern, will spread significant rain and snow through the province during the overnight hours. Things will start off in the afternoon through the Parkland region with snow spreading eastwards from Saskatchewan. As the system pushes towards the Interlake and Red River Valley, precipitation will extend southwards, primarily as rain and then push eastwards through the remainder of the night. Winds will also be fairly strong, with sustained winds around 30-40km/h and gusts up to 60km/h.

Multiple precipitation types will be coming into play again with this system. The primary rain-snow line, at this point, looks like it will sit 50-100km north of the Trans-Canada highway. This line is not set in stone, however, and will likely meander north and south as temperature profiles change and precipitation intensifies and subsides. Areas near the rain-snow line may see precipitation flip from one to the other multiple times. With this low pressure system freezing rain is not expected, but ice pellets or a rain/snow mix are entirely possible.

Expected precipitation types for tonight's storm system.
Expected precipitation types for tonight’s storm system.

Precipitation, while relatively short-lived, will be fairly intense with this system. The heaviest axis of precipitation looks to extend from Parkland Manitoba, through the southern Interlake and northern Red River Valley and then through SE Manitoba into NW Ontario. For those on the snow side of the rain/snow line in Parkland Manitoba (including Dauphin), snowfall amounts will peak at around 10-20cm with amounts tapering off towards the northern Interlake and the rain/snow line. For the areas that will see rain, amounts will be split into three main groups:

Location Rainfall Amount
Extreme SW Manitoba (Melita) <= 5mm
SW Manitoba & Southern RRV 5-10mm
Winnipeg/Northern RRV & SE Manitoba 10-15mm

Saturday will start off mainly cloudy with mist and fog scattered through the Red River Valley. There will be a slight chance of showers, particularly through the northern half of the valley through Winnipeg and into the Southern Interlake. For any activity that does occur, however, amounts will be fairly minimal. Winds will be relatively light and skies will begin to clear for a sunnier afternoon. The temperature will top out around 10°C.

Saturday night will see temperatures dip to around 0°C with light winds. It’s likely that the substantial precipitation coupled with rapid snow melt and calm winds will produce fairly extensive fog through the Red River Valley. Fog is notoriously difficult to predict, so we’ll keep tabs on things into the evening hours and try to give as much heads up one way or another as to what to expect. Just be aware that for travel overnight Saturday into Sunday, fog may play into the picture.

Warmer Weather Arrives

We’ll start pushing into the significantly warmer weather on Sunday as another low pressure system approaches, bringing with it another pulse of warm air. Temperatures in Winnipeg will climb to around 11°C on Sunday with light winds under mainly sunny skies[1]. Temperatures on Sunday night will drop to around 0°C once again, but we do have an ever so slight chance of seeing some showers overnight as a disturbance tracks along the U.S. border.

Daytime highs should sit near to just above normal through much of next week, generally in the 10-15°C range. No threats for precipitation are expected until the second half of the week.


  1. If we end up with fog on Saturday night, we’ll see a cloudier Sunday morning, however skies should clear by late morning for a sunny afternoon.  ↩

Spring is in Sight

The GFS depicts an upper-level ridge building into our region early next week.
The GFS depicts an upper-level ridge building into our region early next week.

Winter-weary Winnipeggers can take solace in the fact that an end to the never-ending winter is in sight. There is increasing confidence that a large upper-level ridge will build into the Central U.S. and Southern Prairies early next week and finally bring some seasonal to slightly above seasonal temperatures to the region. First, though, we’ll have to make it through the rest of the week.

A Cold End to the Week

Cold temperatures will continue to persist through the remainder of the week with well below seasonal highs and lows expected. These cold temperatures are being caused by a large stationary trough of cold air over Hudson Bay that has locked the eastern Prairies into a northwesterly flow that has allowed cold Arctic air to spill southwards, dashing the warm-weather hopes of battered and beleaguered Manitobans.

Wednesday
-2°C / -17°C
A few clouds.

Thursday
0°C / -10°C
Partly cloudy. Slight chance of flurries.

Friday
5°C / 1°C
Late day cloudiness; warming up.

Tonight will be the coldest night for the remainder of the week in the Red River Valley thanks to another push of cold air on the back side of a low pressure system passing to our south. There will be a strong chance of another swath of record low temperatures broken – similar to Monday night – as overnight lows dip some 15-20°C below normal.

Thursday brings a similar high to today, around -2°C, however temperatures just off the ground will be a little bit cooler. This combination will result in stronger low-level instability and we could potentially see a few light flurries develop through the Red River Vally similar to what was seen on Monday afternoon. Overall the risk is very slight, though. Temperatures will drop to a more mild -10°C Thursday night as warmer air begins pushing eastwards.

Friday will be the warmest day so far this week. Temperatures look to climb above the freezing mark towards +4 or +5°C with only a bit of cloudiness to contend with. Winds will be a little breezy out of the southeast to around 20-30km/h, but overall it will be quite a pleasant day with plenty of sunshine. Some cloud will begin streaming in late in the day ahead of the next system pushing towards the region. The cloudier skies will help keep our overnight low fairly warm, with a chance we won’t even drop below 0°C. We may have to contend with some unpleasant weather through the overnight hours, though…

Big Shift on the Weekend

Precipitation amounts forecast on Friday night by the GDPS.
Precipitation amounts forecast on Friday night by the GDPS.

Models are all hinting towards some precipitation on Friday night into Saturday morning as a low pressure system lifts northeastwards through the Prairies. It’s still far too early to speak towards the system in much detail at all, other than saying the bulk of it looks to happen during the overnight period. Some models, such as the pictured output from the GDPS[1] really wind the system up and produce significant quantities of rain or snow while others lift the system much further north with little precipitation development. We’ll have more details on precipitation type and how much of what to expect later on in the week.

The bigger news is that this system marks a significant pattern shift as the upper level ridge we mentioned at the beginning of the article begins developing and pushing eastwards. As it does so, warmer air looks set to flood the Prairies, quickly launching our temperatures back towards seasonal to above-seasonal. Sunday will have temperatures close to normal[2] and we might see it get as warm as the low-to-mid teens on Monday, if we can manage to work past our snow cover.

Multiple days of near-to-just-above freezing temperatures coupled with the strong April sun should do quick work to melt the remaining snowpack across much of the Red River Valley. Melt will be minimal until the weekend, but even one or two days with temperatures in the 5-10°C range will do quick work with much of the remaining snow. Once we can eliminate the snow pack, extremely abnormal cold will be much harder to come by and it will be much easier to see seasonal temperatures.


  1. Global Deterministic Prediction System – Canada’s long-term forecast model.  ↩
  2. Seasonal temperatures for Winnipeg currently are around 11°C for a daytime high and 0°C for an overnight low.  ↩

Remember Winter?

Expected precipitation types on Saturday.
Expected precipitation types on Saturday.

Supplications for summer will be silenced as the stage is set for a sloppy spring storm that will supply snow to Southern Manitoba. Two disturbances will impact the region – one this morning and the other tonight through Saturday – and bring decidedly messy spring-time weather to the region followed by a surprisingly cold air mass for mid-April. Get those snow shovels out and read on to find out what to expect in your area.

Disturbance

The leading disturbance moving through the province this morning is by far the weaker of the two and will move through quite quickly. Disorganized showers or flurries are possible across the region through the morning hours, then we’ll see the clouds begin to clear out giving some sun for the afternoon. We’ll reach a high of only around +4°C today with light northeasterly winds.

Friday
4°C / -3°C
Cloudy periods. Slight chance of morning flurries or showers.
Saturday
1°C / -8°C
Snow. 5-10cm.
Sunday
-2°C / -14°C
Mainly sunny.

Disturbance

Our reprieve from the snow threat will be short-lived, however, as another system pushes into Southern Manitoba tonight. Cloud will stream into the Red River Valley this evening ahead of the main precipitation associated with this low, which will not push into the RRV until the second half of the overnight period. Temperatures will drop to only around -3 or -4°C overnight.

As the precipitation shield undergoes rapid expansion early in the evening, snow, heavy at times, will fall along and south of the Trans-Canada Highway in southwestern Manitoba through a good portion of the night which will result in some of the highest accumulations for this storm. By the time all is said and done, 10-20cm of snow is possible over southwest Manitoba.

Further east in the Red River Valley, snow will push in much later in the overnight period, first spreading into the Morden/Winkler region and then pushing northeastwards. Snow will reach Winnipeg by early Saturday morning. The heaviest snow will fall in the southern portion of the RRV with enhanced amounts possible in the southwest corner near the escarpment where upslope winds will help enhance snowfall.

The main snowfall event for the Red River Valley will occur through the day on Saturday. Weak warm advection aloft will do little to help temperatures at the surface which will be stuck out of the north feeding cooler, dryer air into this system. Coupled with the snow, temperatures through the valley won’t climb much more than a degree or two above zero. It will likely be warm enough at the surface (and aloft) to melt some of the snow that falls. This will reduce snowfall amounts a bit, but given the intensity of the precipitation expected, snow accumulation should overpower the melting factor fairly quickly.

Total snowfall expected Friday night through Saturday. Amounts may be lower depending on how much melts.
Total snowfall expected Friday night through Saturday. Amounts may be lower depending on how much melts.

In general, most areas seem to be set to see around 5-10cm of snow, perhaps a little less if there’s more melting. With temperatures near zero, it will be a somewhat wet, heavy, sloppy snow that will likely make driving very unpleasant and slippery. The snow should taper off on Saturday evening as the system pushes off to the east. Skies will clear in advance of an Arctic ridge pushing into the Prairies and we’ll drop to an overnight low near -8 or -9°C.

Cooler Weather Ahead

Behind this system, very cool arctic air will push into the Prairies. Sunday will be mainly sunny with some afternoon cloud but the temperature will top out more than 10°C below normal at only around -2°C.

The start of next week continues the sunny trend, although Monday will be nearly 20°C below normal with a high of only -8°C. More seasonal air looks to build back in midweek.