Tag: Colorado Low

Spring Storm to be Followed by Much Warmer Weather

Brad 2 Comments

A Colorado Low is on the way to Southern Manitoba and will bring snow and blowing snow to the region beginning Tuesday night. This storm will exit the region on Thursday, and after a couple cool days much warmer spring weather will move into the province.

Weather alert map valid 0827Z Tuesday April 4, 2023
Winter storm warnings are out across southern Manitoba (red on the Canadian side of the border) with blizzard warnings across much of the Northern Plains of the United States (red south of the international border) for a potent spring storm moving into the region. Image valid at 8:30 AM Tuesday March 4, 2023.

A Colorado Low is organizing south of the border that will bring a blast of winter weather to parts of southern Manitoba. It has already begun to spread a band of snow through South Dakota that will lift north-northeast through the day today.

In Southern Manitoba, the snow will approach the southern border by evening, then spread into the province overnight. Light snow will fall across southwest Manitoba, with heavier snow pushing into the Red River Valley and southeastern corner of the province. The Trans-Canada Highway corridor in the RRV will likely receive 5–10 cm of snow by Wednesday morning with higher amounts of 10–20 cm to the south and southeast.

Snow will continue across the Red River Valley and east on Wednesday with another 5 to 10 cm likely in most regions. The snow will finally begin to taper off on Wednesday night. By the time all is said and done, much of southern Manitoba will receive 15 to 25 cm of snow; amounts will drop off quickly west and north of a line running roughly from Pilot Mound to Berens River. The heaviest amounts could reach into the 30 to 40 cm range with the highest risk for that much snow focused in two locations: Sprague and the southwest Red River Valley, particularly in the areas closer to the western escarpment.

RDPS Total Accumulated Snowfall Forecast (10:1 SLR) valid 12Z Thursday April 6, 2023
Much of southern Manitoba will see notable snowfall accumulation as the region is clipped by a Colorado Low Tuesday night through Wednesday.

In addition to the snow, moderate northwesterly winds will develop on Wednesday, bringing areas of blowing snow to the Red River Valley. In combination with the moderate falling snow, expect poor travel conditions across the region, including southward into the United States, Tuesday night through Thursday.

Please refer to the Meteorological Service of Canada for the latest weather alerts for Manitoba.

Temperatures will run seasonably cool through the storm with highs in the -5 to 0 °C range over the next few days. Lows will generally sit in the -5 to -10 °C range, except for Thursday night where clear skies will combine with the fresh snow to send lows into the mid-minus teens.

Long Range Outlook

Probably just as notable as all the snow coming over the next couple days will be the forecast for the weekend. As the Colorado Low pushes northwards, it will dislodge the Polar Vortex and send it further north, finally loosening its influence over the eastern Prairies. A more zonal flow aloft will develop over the region, and much warmer Pacific air will begin to sweep across the Prairies this weekend.

The extensive snow pack over the region will limit daytime highs into the low to mid-single digits. If the ground were completely bare and skies were sunny, daytime highs in the mid-teens could be possible Sunday into Monday; alas. But in addition to temperatures climbing above freezing, this push of warm air will also likely send dew point values above 0 °C as well.

Dew point values rising above freezing greatly enhance how quickly snow can melt, and although the warmer weather will be welcome, it may result in a lot of melting from Saturday through Wednesday. Given the pre-existing concern in Manitoba’s flood forecast, this could result in a higher flood risk for some areas. Be sure to watch for updated Manitoba Flood Forecasts and Reports if you are concerned that you may be impacted by a quick melt.

Today’s seasonal daytime high in Winnipeg is 7 °C while the seasonal overnight low is -4 °C.

Colorado Low Brings Mild Temperatures and Snow to Southern Manitoba

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A Colorado Low moving into the American Mid-West will spread snow northwards into southern Manitoba this week with significant amounts possible.

RDPS Total Snowfall (10:1 SLR) Forecast valid 06Z Tuesday December 13 through 12Z Friday December 16, 2022. Image depicts heavy snowfall over southern Manitoba in excess of 20 cm.
Snowfall accumulations will climb to significant amounts as a prolonged snowfall event begins on Tuesday night and persists until Friday. These accumulations are from one weather model and should be taken more as a signal for snowfall accumulations of 15 to 30 cm rather than a precise forecast.

The weather driver over the next few days will be a Colorado Low passing to the south. It will eject northwards into Nebraska today, spreading heavy snow across the Dakotas. Some light snow will persist across southwest Manitoba today, but the organized, heavier snow will begin to breach the international border later in the day. Temperatures will be mild through the Red River Valley with daytime highs near the freezing mark and easterly winds picking up into the 20 to 30 km/h range.

Organized snow will lift north through the Red River Valley overnight and persist into Wednesday as moisture travels northwards along a stalled inverted trough.. The snow will likely arrive in waves through the day on Wednesday with highly variable accumulations across the Red River Valley. The heaviest snow in the region will fall along the western escarpment where easterly winds blowing up the slope will result in more intense snowfall rates. Snowfall accumulations ranging from 2 to 5 cm up to as much as 20 to 30 cm will be possible by Thursday morning.

What happens after that is a bit of an interesting interaction with a renewed shot of moisture into the Colorado Low on Thursday, the still-stalled inverted trough hanging back from the system, and a cold front advancing towards the region. There is reasonable confidence that another wave of moderate to heavy snow will push into southern Manitoba from the east later on Thursday. This band of snow will persist through Thursday night, gradually pushing towards the Saskatchewan border. This system could bring another 10 to 20 cm of snow to the Red River Valley by Friday morning, including for Winnipeg.

Daytime highs will hover near freezing through Wednesday, then gradually drop through the day Thursday and Friday to around -5 °C. So while temperatures will be pleasant, most of the region is poised to receive anywhere from “some” to “a lot” of snow over the next few days.

Long Range Outlook

Periods of light snow will likely linger into the weekend, but accumulations will be much less. Daytime highs will fall through the weekend as colder air filters in behind this whole disturbance. While Saturday will be pleasant with a high near -8 °C, by Sunday temperatures will fall into the minus mid-teens and barely recover. 

Even colder weather will start next week, but a bit of moderation will occur as another disturbance brings snow to the region on Tuesday into Wednesday.pi…

Today’s seasonal daytime high in Winnipeg is -10 °C while the seasonal overnight low is -19 °C.

#awm

Mild Friday, Then Colorado Low Looms

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It will be another relatively mild day in Winnipeg today, but a developing Colorado Low will begin to impact the region this weekend.

RDPS 2m Temperature Forecast valid 21Z Sunday October 23, 2022
A potent Colorado Low system will develop over the course of the weekend and begin moving into the province later on Sunday.

A sunny start to the day will give way to increasing cloud this afternoon in Winnipeg today. Temperatures will stay mild with a high in the low to mid-teens and westerly winds around 20 km/h.

As cloud continues to thicken up this evening, it will mark the low arrival of a developing Colorado Low. With a low down to the mid-single digits, rain showers will begin to blossom across southern Manitoba late Friday night. Driven by a warm front lifting through North Dakota, these showers will push northeast through Saturday morning. Rainfall accumulations won’t be too significant at just a couple millimetres as the showers taper off in the afternoon.

Temperatures on Saturday will climb into the low teens with a wind picking up out of the northeast into the 15 to 25 km/h range. Temperatures will head down to a low in the mid-single digits again on Saturday night under cloudy skies.

On Sunday, skies will stay cloudy as a warm front surges northwards across the American Plains. By late afternoon, this front will arc from the Dakotas across northern Minnesota and Lake Superior. This will strengthen the northeasterly winds in southern Manitoba into the 30 to 40 km/h range for the day. It will also help to support a band of precipitation stretching from southeastern Saskatchewan across Western Manitoba. This will fall as a mix of rain and snow over Saskatchewan, trending toward snow as Sunday evening wears on and the precipitation moves into Manitoba.

On Sunday night, the brunt of this system will begin to impact Manitoba . Temperatures will remain warm in the Red River Valley as the low lifts northwards; Winnipeg will only dip into the mid- to upper single digits overnight. Rain will likely develop across the region Sunday night, but west of Brandon the precipitation will transition to snow. Here in the Red River Valley, rain could be heavy at times depending on how the system develops.

Long Range Outlook

Rain or drizzle will continue across the Red River Valley on Monday as the low centre passes through the province. Once the low is by, strong northwest winds will develop and usher in much cooler temperatures. Some snow may mix into the precipitation later in the day. Temperatures will dip back below freezing on Monday night. A bit of rain or snow is also possible on Tuesday before things finally settle down.

Much cooler conditions are in store for the rest of the week with daytime highs only reaching the mid-single digits. It will likely stay on the cloudier side, so overnight lows won’t be too bad, dipping just a couple degrees below zero or so. If we end up with a clear night next week, we could see overnight lows dip back into the -5 to -10 °C range.

So…enjoy the weather out there today; it’ll only get less pleasant as the weekend progresses!

Today’s seasonal daytime high in Winnipeg is 8 °C while the seasonal overnight low is -2 °C.

Seasonal Spring Weekend Ahead

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After Wednesday’s winter reminder, typical spring weather will return to the region for the region. A potential major spring storm looms next week.

RDPS 2m Temperature Forecast valid 21Z Sunday April 10, 2022
Mild spring temperatures are likely across southern Manitoba on Sunday.

The main weather feature today will be a ridge of high pressure moving over the region. It will bring an end to the strong northerly winds seen the past few days with sunny skies today.

The ridge will shift off to the east on Saturday with a stronger low developing behind it in the western Prairies. This will spread some cloud cover into the region with strengthening southerly winds. As this low crosses the Prairies, it will bring seasonal highs and slightly mild lows to the Winnipeg area.

On Sunday, cloudy skies will likely give way to some late-day showers as a trough of low pressure moves into the region. Sunday has the potential to produce slightly speedier snow melt as warmer weather arrives dew point temperatures climb above freezing through the day. The Winnipeg area could see daytime highs close to 10 °C despite the cloudy skies.

Most of the rain showers will lift out of the Dakotas and push northeastwards across the region. There is some uncertainty with the track right now and Winnipeg may end up missing out on the rain if things shift eastwards slightly.

Long Range Outlook

Monday and Tuesday will bring pleasant spring weather to the region. Through the second half of next week, however, the potential for a significant storm is brewing.

Most weather models have a potent Colorado Low forming on Tuesday that moves into Minnesota by Thursday evening. As it moves northeast, forecasts show large area of moderate to heavy precipitation. The moisture for this would be fed by extensive thunderstorm activity along the system’s frontal wave in the southeast flank. There is still notable uncertainty, but indications are that it’s highly likely southern Manitoba will be impacted by this storm.

ECMWF 24hr. Precipitation Accumulation Forecast valid 06Z Friday April 15, 2022
The ECMWF places Manitoba’s Red River Valley under the heaviest axis of precipitation from this storm system.
GFS 24hr. Precipitation Accumulation Forecast valid 06Z Thursday April 14, 2022
The GFS model produces notable precipitation over the Red River Valley, but over a smaller area and brings the system through earlier and faster.
GDPS 24hr. Precipitation Accumulation Forecast valid 00Z Friday April 14, 2022
The Canadian GDPS model has a solution between the GFS and ECMWF: a bit slower than one with a precipitation envelope that looks closer to the other.

This would likely take the form of an initial wave of snow or mixed precipitation on Wednesday, followed by moderate to heavy snow on Thursday. In this situation, all the precipitation would taper off for Friday. In this outcome, the region would see significant snowfall with at least 10–20 cm of heavy snow likely.

Some other models keep the system a bit weaker and more progressive; in those cases, the region would see significantly less precipitation with impact over a shorter period of time.

Be ready for the chance of a large spring storm in the future; we’ll be keeping an eye on the forecasts as they develop and have more details early next week!

Today’s seasonal daytime high in Winnipeg is 8 °C while the seasonal overnight low is -4 °C.