Tag: Rain

Spring Warmth Brings Showers

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Springtime warmth will arrive in Winnipeg as temperatures climb above the freezing mark, but the warmer weather will be accompanied by some rain and snow as a low pressure system moves through the region.

Today will be a very pleasant day in Winnipeg with sunny skies in the morning giving way to mixed skies with temperatures climbing to a high near -2°C.1 Winds will pick up out of the south to around 30 km/h this afternoon. Tonight will bring increasing cloudiness overnight as temperatures drop to a low near -5°C with southerly winds continuing at 20-30 km/h.

Tomorrow will be the mildest day of the next few as an approaching low pressure system moves through the region. Skies will be mainly cloudy to start the day and continue to be cloudy for the remainder of the day. A warm front will move across the Red River Valley through the afternoon, bringing milder temperatures as highs climb to around the +3°C mark. Along with the warmer weather, rain will spread across the Red River Valley in the afternoon with the warm front.2 It appears at this point that the Red River Valley will likely receive 2-4 mm of rain, so nothing too dramatic, although there are some models indicating the potential for 10-15 mm.

The RDPS model is a bit more enthusiastic than the other models, producing around 10mm of rain in the Red River Valley.

The light rain will end in the evening, followed quickly by the winds diminishing. The cloudy skies and warm air over the Red River Valley will keep overnight lows fairly warm, with Winnipeg dropping to around 0°C for a low. Towards early Friday morning, winds will then pick back up out of the northwest as the cold front swings through, which will bring cooler temperatures back into the region.

Friday will continue with mainly cloudy skies and fairly strong northwesterly winds to 40-50 km/h. Temperatures will remain steady near 0°C as any diurnal warming will be offset by the cooler air mass moving into the region. Throughout much of the day there will a decent chance for light snow, but no accumulations are expected at this point.

Friday night will bring diminishing winds, clearing skies, and cooler temperatures with overnight lows dropping to around -14°C.

Long Range

The weekend is looking quite pleasant with partly cloudy skies both Saturday and Sunday and high temperatures climbing back to above normal. At this point, Sunday is looking like it could be quite warm with highs in the 4-8°C range, although those warmer temperatures would likely come with a decent southerly wind. The hope at this point is that any precipitation associated with this warm-up will move across the central and northern Prairies, leaving us dry.

Into next week it looks like a return to near-seasonal temperatures and dry conditions.

Winnipeg’s seasonal daytime high is currently -1°C while the seasonal overnight low is -11°C.

  1. While our high is forecast for the airport location, it's quite likely several sites across Winnipeg see high temperatures closer to +1 or +2°C. ↩
  2. There's a chance that the early stages of the precipitation fall as snow if temperatures haven't warmed quite enough yet, but the transition to rain would follow quickly. ↩

Major Winter Storm on the Doorstep

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A winter storm rapidly developing over North Dakota will spread snow, freezing rain and showers into Manitoba today, along with increasingly strong northwesterly winds. Conditions will deteriorate rapidly this morning over western Manitoba, while the Red River Valley and southeastern Manitoba see conditions deteriorate later this afternoon when temperatures begin to drop and any showers change over to snow.

Winnipeg Forecast

Warm air will be reinforced over the Red River Valley ahead of this low pressure system as east to southeasterly winds increase to around 30 gusting 50 km/h develop, keeping temperatures mild with highs near 3°C today. An area of showers will develop as the main low centre lifts into the province out of North Dakota a bit later in the morning, spreading northwards through the afternoon. Rainfall totals throughout the Red River Valley will be variable thanks to the showery nature of the rain, but in general between 2-10mm seems most likely. If some more intense showers develop, there may be a chance for isolated accumulations of 10-20 mm.

Winds will taper off late this afternoon into the early evening as the centre of the low passes through the region. As it moves off to the northeast, winds will then abruptly strengthen out of the west to northwest at 40-50 km/h with gusts up to 70 km/h. Temperatures will quickly drop below zero as some wrap-around snow moves into the Red River Valley.

While some earlier forecasts were showing significant snowfall in the Red River Valley, it looks like the bulk of the snow with this storm will fall over western and northern Manitoba. Here in the valley, the best current indications are that we’ll see a couple centimetres of snow. There are a few outlier models that suggest a secondary shortwave could produce heavy snow over the region in the second half of the night, but I don’t have a lot of confidence in that. I’ll be providing updates via our Facebook and Twitter pages tomorrow night.

RDPS Snowfall Forecast valid Monday Night (00-12Z Tuesday March 7, 2016)
GFS Snowfall Forecast valid Monday Night (00-12Z Tuesday March 7, 2016)
NAM Snowfall Forecast valid Monday Night (00-12Z Tuesday March 7, 2016)

The strong winds will persist all night, which when combined with a couple centimetres of new snow may be enough to create local areas of poor visibilities in blowing snow. Temperatures will drop to a low near -10°C.

Tuesday will bring more periods of snow to the Red River Valley with continuing strong winds out of the west. Temperatures will remain steady near around -11 or -12°C. Temperatures will drop to around -16°C on Tuesday night with more strong winds. Any remaining light snow should taper off overnight.

Wednesday will bring an end to the influence of this storm system. The clouds should break up a bit as the winds taper off through the day. Temperatures will remain cool with a high near -10°C. Expect some more clear breaks overnight as an Arctic ridge pushes into the region. Temperatures will fall well below normal with a low near -19°C.

The Big Picture

Rainfall

Rainfall will be the primary story for much of southern Manitoba today as an area of showers develops ahead of a warm front lifting northwards from the United States.

Areas in Manitoba that will see rainfall today.

The biggest unknown is exactly how much rain will fall, which will depend on how intense the area of showers can manage to develop. At the moment it looks like most areas will see 2-5 mm, however there is the potential for higher widespread amounts of 10-15 mm further north in the Interlake. Should any potent convective cells develop, which may happen anywhere in the rain area today, they may be capable of producing isolated accumulations of 10-20 mm.

The rain will move out of the province this evening, replaced by snow.

Freezing Rain

The risk of freezing rain will appear today through western Manitoba into the Interlake.

Freezing rain is possible over western Manitoba & the Interlake today and into tonight.

The threat for freezing rain will move into western Manitoba this morning and persist until midday. Accumulating freezing rain is possible, with the risk for several mm of ice accumulation. This threat will then lift into the Interlake for the afternoon and onwards into northern Manitoba tonight.

Snowfall

The major impact from this storm will the snowfall and associated winds.

A major snowfall event will occur over eastern Saskatchewan, western Manitoba and northern Manitboa with this winter storm.

The snow is already falling across eastern Saskatchewan and northern Manitoba and will spread eastwards into western Manitoba for the afternoon. Snowfall amounts will be major, with upwards of 40-50 cm expected to fall through the heaviest band in Northern Manitoba. Further south, a north-south swath of 10-30 cm will pile up by Tuesday morning. There will be a relatively sharp cut-off from the heavy snow to just minor accumulations on both the eastern/southeastern and western flanks.

This heavy snow will combine with strong northwest to westerly winds to produce an extended period of blizzard conditions, likely lasting over 24 hours. If you are in the areas that will see heavy snow move in today, it will be best to avoid all travel until conditions improve.

Long Range

Once everything finally calms down on Wednesday, we’ll move into an extended period of below-normal temperatures with daytime highs falling to the mid-minus teens and lows falling below -20°C. No precipitation is expected in the second half of the week.

Winnipeg’s seasonal daytime high is currently -4°C while the seasonal overnight low is -14°C.

Rain Expected Today In The Red River Valley

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A complex low pressure system moving across Manitoba today likely bring record-breaking rainfall to Winnipeg as showers develop along a cold front sweeping eastwards. Behind this feature, things will cool slightly, returning the region to near-seasonal temperatures with a few chances for some light snow.

Today’s main weather story will be a low pressure system lifting northeastwards through the Interlake that will push a cold front eastwards across the Red River Valley & Whiteshell. Ahead of this front, temperatures will climb to a high near 4°C with light southerly winds. As the front pushes through later this morning, an area of showers will develop and spread eastwards. The rain has the potential to be relatively heavy (for February in southern Manitoba), and will produce a swath of accumulations generally in the range of 4-8mm, with lower amounts to the west of the main development and localized potential for 8-15mm although those higher amounts would likely be restrained to near the Ontario border.

The NAM’s simulated RADAR imagery shows the main area of rain passing just to the southeast of Winnipeg.

There’s a little uncertainty as to how far west and north the precipitation will push, however it seems likely that Winnipeg will see some rain with 2-5 mm very likely. There’s a smaller chance that we’ll see amounts higher than that, but that will become more clear this morning as the rain develops. Winnipeg’s daily rainfall record for February 20th is 0.3 mm, set in 1965. This makes breaking the record almost a near-certainty today.

Winds shift out of the west behind the front to west-southwesterly at around 20-30 km/h. Temperatures will fall to a low near -1°C overnight under mostly cloudy skies.

Tuesday will bring a mix of sun and cloud to the region with mild weather still in place as temperatures climb to a high near 3°C. Expect increasing cloudiness on Tuesday night with temperatures dropping to a low near -2°C.

Wednesday will bring another low pressure system to the region, this time skirting across southern Manitoba near the US border. This system will spread an area of snow along and just north of the low track. Total amounts, at this point, look like 5-10 cm over the southwestern portion of the province, tapering off to 4-8 cm over the Red River Valley and 2-5 cm over the southeastern corner of the province. Winnipeg’s high temperature will climb to around -1°C, but temperatures may climb to 0 to +1°C over the southern Red River Valley if the low tracks far enough north. Expect a low near -8°C on Wednesday night with gradually clearing skies.

Long Range

The long-range forecast looks cooler, but still relatively pleasant. Winnipeg will likely see variable cloudiness through the second half of the week as temperatures fall back to seasonal to slightly below seasonal temperatures. Nothing significant is expected for snow between Thursday and the end of the weekend.

Winnipeg’s seasonal daytime high is currently -7°C while the seasonal overnight low is -17°C.

Unseasonal Warmth Will Challenge Numerous Records

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Winnipeg will see the peak warmth of the current weather system move in today with temperatures climbing well above the freezing mark. The unseasonable warmth will challenge several record types: record highs, record high minimums, record high dew points, and record high minimum dew points.

Everything ending in °C will be the highlight over the coming days as even more warm air floods into the region. Today’s high will reach around 4°C, while tomorrow’s and Sunday’s highs will be near 3°C. Overnight lows will remain very mild as well, with lows near 0°C tonight, -5°C tomorrow night and +1°C on Sunday night.

Winnipeg, MB Temperature & Dewpoint Records for February 17-19
Date Record Type Current Record
February 17 High Temperature 5.4°C (1981)
High Minimum Temperature 0.8 (1998)
High Dewpoint 2.0°C (1981)
High Minimum Dewpoint -0.6°C (1998)
February 18 High Temperature 3.9°C (1954)
High Minimum Temperature -0.2°C (1998)
High Dewpoint 0.6°C (1954)
High Minimum Dewpoint -1.3°C (1998)
February 19 High Temperature 5.6°C (1930)
High Minimum Temperature 0.2°C (2016)
High Dewpoint 0.6°C (1954)
High Minimum Dewpoint -0.5°C (1981)

These temperatures will challenge many of the records listed above. For daytime highs, it’s important to note that there will likely be significant variability around the city. The official records are for the official Environment & Climate Change Canada observing site located at the Winnipeg airport, which tends to be colder than much of the city during warm spells at this time of year. Throughout the city, temperatures could be anywhere from 2-4°C higher than what’s reported at the ECCC site.

The GDPS is forecasting temperatures up to 12-14°C above normal over the coming few days in Winnipeg.

Skies will see variable cloudiness over the next few days, but we’ll see no real threat of precipitation aside from a very low chance of a light rain shower this evening.

Winds will strength out of the southwest today to around 25-35 km/h with some gustiness, particularly near the western escarpment of the Red River Valley. These winds will continue overnight and then gradually taper off on Saturday. The wind will then swing around to the east/southeast on Saturday night and begin strengthening on Sunday to 20-30 km/h ahead of the next system.

Long Range

The beginning of next week will bring a Colorado Low that poses the threat for significant impact on the region, however it’s difficult to pin down much of a forecast at this point as solutions for this disturbance vary dramatically, with some models dragging the precipitation of the low up the Saskatchewan/Manitoba border and others shunting it well off to the east over Lake Superior.

What we can say is that there will be a Colorado Low that will threaten the region on Monday, potentially into Tuesday. This system will be bringing an abnormally high amount of moisture with it, and with the mild temperatures, that means that any precipitation from it would fall as rain. Forecast amounts have varied, but in general it seems like this system will produce a swath that receives 10-20mm of rain. Whether or not that falls in the Red River Valley will yet to be seen.

That much rainfall would be very abnormal for this time of year. Current rainfall records for this general time of year are:

Winnipeg, MB Rainfall Records for February 19-21
Date Record Type Current Record
February 19 Rainfall 1.0mm (1997)
February 20 Rainfall 0.3mm (1965)
February 21 Rainfall 5.8mm (1877)

The potential to over double the current record rainfall amount, all the while still having frozen ground with high water content and a fair amount of snow would likely introduce a risk for overland flooding.1 In North Dakota, the NWS has issued hazardous weather outlooks regarding this system for the potential for minor water level rises in low-lying areas and for area rivers. In the end, though, there’s still a lot of uncertainty in where exactly this system will track, so we’ll be keeping an eye on things as it develops.

Otherwise, temperatures will finally begin to cool back towards normal behind this system, but it continues to appear like southern Manitoba will be near the primary storm track and see more frequently unsettled weather through the remainder of next week.

Winnipeg’s seasonal daytime high is currently -8°C while the seasonal overnight low is -18°C.

  1. While I do have training in meteorology, this sort of issue is more of a hydrological challenge. I’m not formally trained in hydrology, but the fields are closely related and I do have some familiarity with it. That said, as it gets closer, monitor the news for any statements from the Province of Manitoba regarding the flooding threat. ↩