Warm Weather ushers in Another Colorado Low Pressure System

Our region as a whole has experienced a mixture of  warm and cooler than average temperatures over the past week, as well as a clipper that affected our region yesterday on Wednesday. Unfortunately that has already shifted over and a Colorado low has begun to effect us. This system will bring everything from snow to thunderstorms. Multiple alerts are in effect for this system, please read them here at  https://weather.gc.ca/warnings/index_e.html?prov=mb Read on to Find out what we can expect. Use spotwx.com to access your local regions weather forecast. This blog took me 5 hours to write so please let me know your thoughts. 

Friday (Above): A large swath of rain will develop and fall across the southern half of Manitoba during the day . The beginning stages and this part of the system will give moderate rainfall throughout the day, there’s enough of a chance that a general 5 to 15mm is possible during the afternoon in the red river valley. Before a lull of activity by the early evening with some light rain falling in the interlakes regions.  There’s a chance that even more could fall , based on the HRRR model with upwards of as much as 30mm falling. Temperatures will sit in the low to mid single digits on Friday. With high temperatures across the south between +1 and +3C. 

Friday Night (Above): This is when the system really starts increasing in moisture and the warm front brings in more instability. By this time the low will move into North Dakota. A batch of rain and thunderstorms state side will begin to develop, and move northwards they will impact southern Manitoba and the red river valley.

There’s a chance that some areas in the rain will have lightning and thunderstorms embedded in them. I’m not expecting anything severe however. A general 10 to 15 mm can be expected overnight with the heaviest of the rainfall occurring along and south of the transcanada highway. I’m not seeing any consensus on any snowfall occurring or freezing rain until the early morning hours. Temperatures tonight will drop into the low to mid single digits (1 to 4C) with some areas only sitting around the 0C mark, especially in rural snowcovered areas. 

Saturday (Above RDPS Canadian model): Heading into the day Saturday this is when the weather will begin to turn around, a large area of precipitation will move over much of southern Manitoba. During the morning hours chance of freezing rain will develop in the southwest part of Manitoba. It’s important to mention that this will probably be the beginning of the most impactful weather.  Southwest Manitoba will experience periods of freezing rain with areas in the extreme southwest the most at risk by around lunchtime, what will happen is that this will eventually move northeast through the rest of the afternoon and early evening. 

THUNDERSTORMS AND RAINFALL (RED RIVER VALLEY, SOUTHWEST MB AND SOUTHEAST MB) Theres a good chance, that a period of dry weather will occur in the afternoon, before a resurgence of storms in the afternoon as storms and a large area of rain forms in North Dakota. There’s a decent chance that some of this activity mainly in the red river valley some parts of the southwest part of Manitoba and the southeast will be in the form of thunderstorms, some of them might be strong with the risk of small size hail. These thunderstorms will be elevated however because a moderate amount of instability will be present at middle levels. The NAM is hinting at a general 20 to 30mm with the potential for 35 to 60mm to occur particularly in the red river valley regions, all the way to the border by the pembina valley. The HRRR is hinting at similar amounts. The concern with this is heavy rainfall occurring over the frozen ground will lead to over land flooding, this is why there’s a overland flow flood warning. 

SATURDAY AND SATURDAY NIGHT FREEZING RAIN (SOUTHWESTERN MANITOBA/PARKLANDS and Interlakes)
As for the freezing rain expected, a general 5 to 10+mm of ice, the consensus for this accumulation looks to occur in the Brandon to Manitoba Saskatchewan border towards the American border. This period of freezing rain may start during the morning on Saturday, or start towards the latter half of the day. 

Models are still having a hard time determining the time that it will start, the NAM is showing a large batch of freezing rain sitting over the peace gardens on Saturday moving northeast through the day with patchy freezing rain elsewhere. As the HRRR is showing intermittent freezing rain in the afternoon, in the southwest before a small but intense band moves from the Melita to the Dauphin areas eventually into the interlakes throughout the day but really intensifying by the early evening . Again 5 to 15mm of freezing rain is possible. When it starts could determine the impacts of the system, regardless with the heaviest of the accumulations likely over the international peace gardens region. Power outages are likely if there’s going to be this much in the way of accumulation of ice. Temperatures will sit in the low to mid single digits in the southeast (2 to 6C), areas further west will see high temperature values between 1 and 3C, with the exception of the Riding mountains and the peace Gardens seeing highs around 0C. 

Saturday Night (SNOWFALL AND RAIN CONTINUES ABOVE): This is when things get really interesting, a band of freezing rain will move through southwestern Manitoba into the interlakes during the early evening. A complete switch over to snowfall is likely by the evening and overnight hours, in the southwestern part of Manitoba with a narrow but heavy band of snow occurring from the Melita, Killarney and turtle mountain areas towards the interlakes including the parklands region. A band of mixed precipitation can be expected further east from southern end of lake Manitoba into the Tuelon and the Hecla/Fisher River regions of Lake Winnipeg. A general 15 to 25cm can be expected from the southwestern part of Manitoba into the parklands region, heavy amounts of 30 to 45cm are possible with 50cm in spots in the asseisippi and Swan River area. As for rainfall in the southeastern section of Manitoba and the Red River valley, thunderstorms will be possible in the early evening hours. Some may be strong, with the risk of hail. By the late overnight a general 30 to 60mm will have fallen in the red river regions, the NAM 18z is hinting at 70mm by morning. So it will be interesting to see if we get that much. Saturday Night those warm temperatures we received will only last until shortly after midnight before that cool northwest flow moves in and drops our overnight low temperatures well below average to around the low single digits (0 to 3C). A lot of the warmer air unfortunately will be off to our south. 

Sunday (Above): This is when a majority of the precipitation will shift over, rain will continue in the southeast with a mix of rain and snow occurring over the portage la prairie area down to the pembina valley and the interlakes in the morning. Snow then  will occur in the southeast part of Manitoba, and the interlakes where another 10 to 15cm is likely and locally higher in the pembina valley where 25cm is possible. The wind will take over, winds could gust as high as 70 to 80km/h as the low starts moving east into eastern North Dakota.  Temperatures will take a nosedive as well only reaching the low to mid minus single digits (-1C to -5C), the coldest air in the interlakes regions.  

Sunday Night (Above): This is when the system will start to die down, snow will continue to fall in the southeastern half of the region. A general 2 to 5cm can be expected with light snow occurring overnight. Flurries expected by the morning hours. Blowing snow will die down. Temperatures will drop on Sunday night into the high minus single digits (-5 to -10C).   

Totals for Precipitation using the NAM model, the HRRR is showing similar amounts. It is entirely possible some of these amounts could be underdone or overdone. Again , if you were to encounter heavy snowfall or heavy rainfall in thunderstorms the amounts could be enhanced. 

Rainfall 20 to 70+mm likely by Sunday:

Snowfall 10 to 60cm possible, heaviest in western Manitoba and in the Pembina valley:

Freezing Rain 5 to 15mm possible as shown on this graphic in the southwest and parklands:

The week ahead: Looks like a good return to calmer weather with high pressure but unfortunately temperatures on Monday will struggle to reach highs above zero with highs in the low to mid minus single digits likely, areas with deeper snowpack will see lows in the minus trend (-10 to -18C), areas like the red river valley will see lows in the high minus single digits (-5 to -7C). The rest of the week temperatures in the low minus single digits are likely with some highs above zero, and moderating temps Tuesday night with lows in the minus single digits. The first temperatures in the teens are likely on Wednesday with lows finally above zero.