Tag: Rain

Rain Expected Today In The Red River Valley

Brad Leave a comment

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

Brad Leave a comment

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. ↩

Colorado Low Looms

Scott Leave a comment

Our first significant Colorado Low in some time will bring a variety of precipitation types to southern Manitoba today. Rain, snow, freezing rain, and ice pellets will be possible.

A variety of precipitation types will be possible in southern Manitoba today. The map shows areas of rain (green), snow (blue), freezing rain (purple), and ice pellets (red).
A variety of precipitation types will be possible in southern Manitoba today. The map shows areas of rain (green), snow (blue), freezing rain (purple), and ice pellets (red).

Today

Monday
2°C / 1°C
Mixed precipitation early, then rain

A powerful Colorado Low will bring a mixed-bag of precipitation to southern Manitoba today. Precipitation will likely start out as freezing rain or ice pellets in portions of the Red River Valley and south-eastern Manitoba this morning, before changing to rain later in the morning. Rainfall amounts of 5-10 mm are expected in most areas, with higher amounts possible near the International border. There may be a bit of snow at times, but little accumulation is expected – and any that were to accumulate will be melted by rain later in the day. However, the story will be different in western Manitoba, where snow will be the dominant precipitation mode for the day. Accumulations of 5-10 cm are likely in most areas by tonight. Winds will be gusty out of the north-east at 30 km/h gusting to 50 km/h, bringing some blowing and drifting to open parts of western Manitoba.

Tuesday

Tuesday
1°C / -1°C
Periods of snow

This Colorado Low will take its time exiting our region, affecting us once again on Tuesday. Unfortunately (for some), rain will change to snow on Tuesday in the Red River Valley and south-eastern Manitoba. Accumulations of 4-8 cm are likely in addition to possibly a couple millimetres of rain or mixed precipitation early in the day. Western Manitoba can expect another 5-10 cm on Tuesday, bringing totals up to 10-20 cm. The model graphic shown below, which considers a wide-range of possible solution, shows a very high probability (>80%) of over 10 mm of total precipitation in most of southern Manitoba. Winds will remain gusty out of the north on Tuesday at 30 km/h gusting to 50 km/h.

Most of southern Manitoba stands a very high chance of receiving over 10 mm of precipitation with this system (NAEFS graphic).
Most of southern Manitoba stands a very high chance of receiving over 10 mm of precipitation with this system (NAEFS graphic).

Wednesday

Wednesday
-1°C / -4°C
Mainly cloudy with flurries

The Colorado Low will continue to linger on Wednesday, but snowfall rates will decrease. Flurries are expected throughout the day, but accumulations should be small. Winds will remain breezy from the north at 20-30 km/h.

Long Range

It appears that we’ll see generally seasonal to slightly-above seasonal temperatures as we move into early December. However, longer-range models do hint at a very cold arctic air mass being pulling down from the north about one week into the month. This will have to be monitored, as it would be our first significant bought of below-normal temperatures in quite awhile.

Coldest Weather So Far This Season Arrives In Big Pattern Shift

Brad 1 Comment

An increasingly active storm track will bring a major winter storm through the Northern Plains of the U.S., drawing colder arctic air southwards cross the Prairies and ushering in the coldest temperatures seen so far in the fall of 2016.

Today will start with a weak system pushing through the Red River Valley, bringing with it a band of showers that will lift northeastwards across the region through the first half of the morning. After that moves through, we’ll be left with fairly cloudy skies as temperatures climb to a high near 9°C. Winds will pick up out of the southeast this morning to around 20-30 km/h, then taper off for the afternoon. Expect the winds to pick back up out of the northwest later in the evening with a slight chance of some very light rain showers or snow flurries overnight as a cold front moves through and temperatures dip down to the 0°C mark.

Thursday will bring mainly cloudy skies as a Colorado Low strengthens south of the border. Winds will be breezy out of the north to northwest at around 20-30 km/h and temperatures will climb to a high of about 3°C.

This history of forecast precipitation for Friday's Colorado Low shows how the GDPS model has developed consistency only in the last day and a half.
This history of forecast precipitation for Friday’s Colorado Low shows how the GDPS model has developed consistency only in the last day and a half.

Since last weekend, it’s been quite clear that a major winter storm was possible on Friday, and that much it got right. However, what at one point looked like a major blizzard for the Red River Valley has since turned into a moderate-strength winter storm for the Dakotas and Minnesota into Wisconsin. There’s a whole discussion on long-range model forecasts, but we’ll leave it at this: while it may get the general pattern right, don’t trust it on the details.

So what will we see instead of a blizzard? Cloudy skies and a stiff north wind likely at 40 gusting to 60 km/h. The southeastern portion of the province may get clipped with some snow from this system, but here in the Red River Valley, the system snow should miss us. There may, however, be a sneak attack from the north as cooler air surges southwards and lake-effect snow fires up over the lakes. Areas in the lee of the lakes may see some light to moderate snow flurries, however these will occur in fairly narrow strips and be highly dependent on the wind direction.

Temperatures will climb to only -1 or 0°C for a high. Expect the cloud and potential lake-effect snow to continue overnight as temperatures fall to a low near -4°C.

Long Range

The weekend looks cool with a continued chance for lake-effect snow through the day on Saturday. Cloud cover will be a mixed bag and highs will be near 0°C with lows near -6°C or so. If we get completely clear skies one night, then temperatures could plummet quite severely, though, so an overnight low below -10°C may be possible if the cloud manages to be scoured out of the Valley.