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.

Beautiful Week Ahead; Stormy Weekend

The Red River Valley will bask in the sunshine through the rest of the work week before a strong spring storm system moves into the area, bringing rain and snow for the weekend.

Unlike our friends to the west in Alberta, where a major winter storm is set to dump 15-25cm of snow through areas west of Highway 2 over the next two days, a ridge in place over Manitoba will keep skies clear and temperatures warm over the next few days, with plenty of sunshine and daytime highs of around 15°C and overnight lows around 2°C.

850mb Winds

850mb winds from the GEMGLB valid 06Z Saturday morning.

Our next weather system will move in this weekend, with an upper trough swinging eastwards across the Prairies. An area of rain will blossom in Saskatchewan through the day on Friday with rainfall intensifying through the day. Embedded thunderstorms may increase rainfall amounts for SK, but currently it looks like rainfall amounts of 20-40mm are possible for SE Saskatchewan, with some models painting as much as 75-85mm of rain! This system will track eastwards into Southern Manitoba through Friday night.

Southern Manitoba will be under the influence of this system through Saturday and Sunday, with some regions seeing rain changing over to snow on Sunday as cold air is wrapped into this system. Given the system’s intensity and its time out, we’ll wait to look at it in more detail on Friday when things are a bit clearer.

For now, get out there and enjoy that sunshine!

Rain on Monday, Nice Midweek

Another weak weather system is in store to start the week. A bit of rain is in the forecast for Monday, but conditions will improve rapidly toward midweek.

Surface map for Monday

HPC’s surface map for Monday showing the location of the cold front

A low pressure system and its associated cold front will generate some light rain over South-Central and Eastern Manitoba on Monday. Accumulations will generally be around 5mm in the Red River Valley and South-Eastern Manitoba. Some areas near the Ontario border may see amounts closer to 10mm. There is a small chance that some thunderstorms may become embedded within the area of rain. Any areas that experience weak thunderstorm activity may see slightly higher rainfall amounts.

Since a cold front will be passing through on Monday temperatures will be cooler than on the weekend. Highs in the Red River Valley and South-Eastern Manitoba will be around 10 degrees. Some areas will be slightly warmer or colder than that mark depending on when the rain starts and how quickly the cold front goes through.

The middle of the week is looking good. Tuesday should be a very nice day with highs in the mid teens and relatively light wind speeds. High temperatures on Wednesday should be in the high teens or near twenty degrees. On Thursday we will have a shot at twenty degrees yet again.

Low pressure system forecast to impact Southern Manitoba next weekend

Low pressure system forecast to impact Southern Manitoba next weekend – image courtesy of College of Dupage

Unfortunately, conditions are forecast to turn unsettled for the weekend. Current models show a strong low pressure system impacting Southern Manitoba on Saturday and Sunday. Should this system pan out, which is never a certainty, it could be both a rain and snow producer. It is too early to get into any further detail, but this potential storm bears watching.

March 2012 was the warmest March on record in Winnipeg since records began in 1872. The month ended up with a mean temperature of +2.2C, which is 8.3 degrees warmer than normal (-6.1C). Prior to this year Winnipeg’s warmest March on record was the March of 1878, with a mean temperature of +1.6C. Below is a recap of the many records broken last month:

  • 8 daily record high temperatures (11, 12, 15, 16, 17, 18, 19, 22)
  • Earliest 20°C reading on record (March 18)
  • Warmest overnight low in March (14°C on the night of March 18/19)
  • Earliest thunderstorm on record since 1953 (Evening of March 19th)
  • Warmest March day on record (March 19th, 23.7°C)
  • Most significant departure from normal temperature for any day of the year (+23.4°C above normal on March 19th)
  • 4 consecutive days over 19°C (Only 4 days since records began have reached that mark. From Rob’s Blog: In other words, it took only 4 days during this warm spell to match what took 140 years to accomplish.)
  • Warmest March on Record (Mean temperature of 2.2°C, beating the previous record of 1.6°C set in 1878).
  • Highest dew point in March (17°C on March 19th, need to finish parsing data set to verify)

Elsewhere in Weather News

Rare, Large Mexican Landspout Touches Down

On the outskirts of the city of Nuevo-Laredo, Mexico, located near the Texan border, an unusual sight could be seen on Thursday, March the 29th. An abnormally large landspout touched down for an extended period of time, picking up dust, trees, shrubs and flipping over a trailer on the highway. In this case, thankfully no one was injured but landspouts are often underestimated and can create as much damage as a tornado, over a smaller area.

Landspout crossing the highway on the outskirts of Nuevo-Laredo on Thursday March 29th. (Source: Melissa Estrada)

Landspout crossing the highway on the outskirts of Nuevo-Laredo on Thursday March 29th. (Source: Melissa Estrada)

The landspout is of the same family as a tornado however they have different characteristics than a tornado, which is typically spawned by a supercell. Landspouts usually spin up under towering cumulus or non-supercellular storms, as the updraft catches the rotation at ground level. This is different compared to a tornado, which starts from the base of a supercell as a funnel and proceeds to drop until it reaches the ground and becomes a tornado. The speed inside this rotating column of air (landspout) increases as the column is stretched out and can possibly become as damaging as a tornado.

The severe, elevated storm also brought with it some hail the size of tennis balls that accompanied the landspout. No other damage other than the flipped trailer was reported as the landspout moved into unpopulated areas of the Mexican plains.

Elsewhere in Weather News has been provided by Matt

Continuing Unsettled Weather

Southern Manitoba will continue to see unsettled weather through the weekend with system after system tracking through our region. Despite this, temperatures will remain above normal, contiuning this month’s summer-like trend.

We’ll start off with clear skies this morning with patchy fog through the Red River Valley which will burn off by mid-to-late morning as that late-March sun gets to work. We’ll see our temperature get up to 12 or 13°C before skies cloud over mid-to-late afternoon. Most areas in the Red River Valley, including Winnipeg, will then have a chance of seeing some showers as a weak warm front pushes eastwards through the area.

GEM-REG Precipitation for Friday Night

GEM-REG Accumulated Precipitation for Friday night.

Overnight, much of the Red River Valley has a decent chance to see rain as the mid-levels destabilize with an injection of cold air at 700mb associated with a shortwave tracking through Central Manitoba. Positioning of the shortwave will be crucial to where the precipitation falls, but current indications are that an area of rain will blossom overnight near Brandon and travel east, with lighter showers south of the Trans-Canada Highway and 4-8mm of rain along and north of the TCH.

That rain will clear out by midday Saturday, and the Red River Valley will be left with just a few clouds and beautiful temperatures around 15°C.

24-Hour Precipitation Accumulation Monday Evening to Tuesday Evening

24-Hour Precipitation Accumulation from Monday evening to Tuesday Evening

It was not mean to last, however, as yet another low begins it’s trek into the Prairies. Winnipeg will get to 11 or 12°C before more clouds push in by mid-afternoon. Light rain will push into the Red River Valley overnight Sunday and then intensify Monday morning, dropping another 5-10mm of rain before it pulls out on Monday evening.

All of these systems are sensitive to exact tracks of subtle features, so we’ll be sure to provide updates in the comments as the weekend progresses. In short, for much of the Red River Valley, the next few days will be unsettled with pleasant temperatures in the low-to-mid teens when the sun manages to poke out and showers/rain every 24-36 hours.