Tag: Snow

Spring is in Sight

Brad Leave a comment
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?

Brad Leave a comment
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 #1

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 #2

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.

March to end with a Bang

Brad Leave a comment

This March not only came in like a lion, it will also go out like a lion. A major winter storm will slam the American Red River Valley and parts of south-eastern Manitoba today. Read on for the details.

A Colorado Low will bring heavy snow to parts of southern Manitoba and the northern United States on Monday
A Colorado Low will bring heavy snow to parts of southern Manitoba and the northern United States on Monday

Monday

Monday
-9°C / -15°C
Snow, heavy in some areas. Windy.

A Colorado Low will bring heavy snow and high winds to the Red River Valley and south-eastern Manitoba today. Wind speeds will range from 40-50km/h gusting to 50-70km/h. Some areas may even see winds as high as 60km/h gusting to 80km/h for a period of time. This will produce blizzard conditions in open areas of the Red River Valley and south-eastern Manitoba. The map below illustrates the expected snowfall totals.

Expected storm-total snowfall amounts.
Expected storm-total snowfall amounts.

Travel will become very difficult, if not impossible from points south of Winnipeg and into the American Red River Valley as the day progresses. Highway closures are likely through the day, with some roadways possibly staying closed until Tuesday. Roads that remain open will be in poor shape as well, so those traveling today may need to reconsider their plans.

This storm will wind down on Tuesday as the snow ends and the wind begins to decrease. However, those areas that saw the heaviest snow will have to deal with large snow drifts on Tuesday. Travel will be difficult if not impossible, particularly in the American Red River Valley, on most of Monday and likely into Tuesday as well. Luckily this storm should signal the beginning of the end of the seemingly endless winter we’ve endured.

Tuesday

Tuesday
-8°C / -22°C
Mainly Sunny

Tuesday will be a much calmer day in southern Manitoba. Temperatures will warm into the minus single digits, but a north-west wind will linger as Monday’s storm departs. At least it will be decent shoveling weather…

Wednesday

Wednesday
-4°C / -18°C
Mainly Sunny

Wednesday will see further improvement over Tuesday, as temperatures climb into the low to mid minus single digits. That should be good enough for some light melting of snow off dark surfaces – melting that can’t come soon enough for most people.

Long Range

The long range forecast is looking good for a change. Most models suggest we’ll see near normal weather in the short to medium term, which means high temperatures in the mid positive single digits. That should help to gradually start wearing down our snow pack.

Elsewhere in Weather News: March 29th, 2014

Matthieu Leave a comment

Atlantic Storm Slams Canadian Maritimes

This past week a strong Nor’easter affected the Canadian Maritimes which brought large amounts of snow as well as record-breaking wind gusts. The dynamic system that started off as a weak low off Florida’s east coast and quickly deepened, over 40mb in 24 hours, over the Gulf Stream. By the time the low had traveled up the East Coast and reached the Canadian Maritimes, it had peaked in strength at 955mb. Although this system, a cold low, was much different dynamically than a hurricane, it brought extreme wind gusts of category 3 strength; 186km/h gust in Wreckhouse, NL (breaking the old record of 180km/h). Widespread 100km/h gusts were reported across both Nova Scotia and Newfoundland.

Impressive picture of the Nor'easter just before the storm reached maximum intensity. (Source: NOAA)
Impressive picture of the Nor’easter before the storm reached maximum intensity. (Source: NOAA)

The forecast proved to be a tough one, especially along Nova Scotia’s coast, where warm air coming off the Atlantic Ocean had an impact on the snow amounts. Widespread amounts of 40cm were reported in both Nova Scotia and New Brunswick. Halifax’s snowfall total, which was affected by the warm air coming off the Atlantic, only received 21cm. The highest total out of all the major Maritime cities was Charlottetown, PEI, which reported an incredible 53cm from the storm and experienced snowfall rates as high as 10cm per hour. Unsurprisingly, about 20,000 people were out of power at some point in the Maritimes and most flights in Halifax were cancelled on Wednesday. The Confederation Bridge connecting PEI to the mainland was also closed, due to the strong winds.

Only to add salt to the wound, the Maritimes are expecting another messy weather system to affect the region Sunday night into Monday. It will bring a mixed bag of precipitation to the region, depending on proximity to the Atlantic Coast; rain and freezing rain can be expected near the coast such as in Halifax. Further inland into New Brunswick, ice pellets/freezing rain transitioning to heavy snow will fall. The precipitation amounts will not be as high as the previous system, but nonetheless significant, as models are snowing that conservatively 15cm could fall in the snowfall region and 20mm of rain near the coast.