Unsettled & Unpleasant May Long Weekend Ahead

Winnipeg, and many other regions in the Red River Valley, received the most significant rainfall so far this year yesterday as an area of moderate rain moved into the province from North Dakota and stalled out for much of the day. Rainfall totals in most places were near 20–30mm with slightly higher amounts in the southwestern Red River Valley:

Rainfall totals for the May 14, 2015
Location Rainfall Total (mm)
Letellier 41
Altona 37.6
Morris 34.2
Winkler 29.8
Steinbach 27.8
Winnipeg 24
Dugald 22
Elm Creek 12.6
Portage la Prairie 9.6

The Altona/Letellier areas seem to be the winners for total rainfall with almost 1.5” of rain in total. Unfortunately for farmers who are still working at getting seed into the ground, there won’t be much of a reprieve from wet weather before more rain is on the way as another major low pressure system is hot on the heels of the previous one and is set to bring a whole host of unsettled, pleasant and stormy weather for the May long weekend.

Pleasant Friday, then Downhill

Friday
18°C / 7°C
Partly Cloudy

Today will be a very pleasant day across the Red River Valley with mainly sunny skies and temperatures climbing into the high teens under partly cloudy skies. Winds will be fairly light out of the northwest. Friday night will see temperatures drop to around 7°C under clear skies. The nice weather won’t last too long, though, as a potent low pressure system moving into the Northern Plains of the United States tonight will result in cloud and some light rain spreading across Southern Manitoba early on Saturday.  The heaviest rainfall will hold off until much later in the day, however, as this system will end up being strongly driven by convection.

SPC Day 3 Convective Outlook valid Saturday May 16, 2015
SPC Day 3 Convective Outlook valid Saturday May 16, 2015

The SPC[1] in the US currently has a slight risk of severe thunderstorms in their outlook for Saturday scrunched right up the Canadian border. Further north in our area, it looks like an initial shot of some showers associated with elevated convection will lift through the region early in the day. Temperatures will warm towards the 20°C mark with an increasing risk of showers or thunderstorms.

Saturday
20°C / 9°C
Cloudy; scattered showers with the risk of a thunderstorm

Later in the afternoon, best indications at this point are that an area of thunderstorms will initiate in North Dakota and push northeastwards through the Red River Valley. It looks like precipitation will most likely be showers or weak thunderstorms, however the outside chance exists that an isolated severe thunderstorm may be seen. A thunderstorm outlook later will be issued later today covering all of Southern Manitoba.

A few showers will be likely through the overnight hours as the temperature drops to 9°C or so.

Sunday will be the most significant precipitation day with rainfall intensifying through the morning into the afternoon. There’s some uncertainty as to where the western cut-off will be for the rain, but general consensus at this point is that the entirety of the Red River Valley will see rain on Sunday.[2] Total accumulations are hard to nail down at this point, but look to be in the 25–50mm range.

Sunday
10°C / -3°C
Rain

Things take an unwelcome turn on Sunday evening as colder air works its way into Southern Manitoba on the back-side of the system. Rain may become mixed with or switch over to snow as it begins tapering off. No significant snow accumulations are expected. Temperatures will drop off to around –3°C on Sunday night with winds gradually tapering off.

Holiday Monday A Cool Improvement

Looking ahead to the start of next week, it looks like Monday will mark the transition out of this active pattern we’ve been in. Sunny skies and exceptionally cool weather look to be on tap with highs struggling to get to even 10°C[3]. Conditions will improve over the subsequent days with drier weather and temperatures returning to the seasonal mark.


  1. Storm Prediction Center  ↩
  2. The GDPS is a bit of an outlier, keeping rain wrapped tightly to the surface low pressure system in Minnesota and keeping the bulk of Sunday’s rain southeast of Winnipeg.  ↩
  3. Average highs for May 18th are around 21°C.  ↩

More Wet Weather Through Second Half of the Week

More wet weather is on the way to Winnipeg & the Red River Valley as a slow-moving upper-level disturbance bears down on Southern Manitoba. The bulk of the rainfall associated with this next system will be quite a bit more concentrated than last week’s Colorado Low with much of the precipitation being produced by a single, relatively narrow band of moderate rainfall sliding across the region.

Winnipeg will see a high of around 12°C today with cloudy skies through the day. Shower activity will push northwards through the Red River Valley over the morning hours bringing a decent chance of some rain to Winnipeg by mid-to-late afternoon. Winds will be breezy out of the southeast at around 30km/h with a bit of gustiness on top.

Clouds will stick around tonight as the temperature drops to around 7°C with a continued slight chance of showers through much of the overnight period. The next disturbance will move into Southern Manitoba late overnight, spreading rain from SW to NE starting near the Pilot Mound/SW RRV region and lifting towards Winnipeg.

NAM 12hr. QPF valid 00Z Friday May 15, 2015
The NAM is forecasting around 10-15mm of rain for much of the Red River Valley on Thursday, with some areas seeing as much as 20-25mm.

Thursday will start off as a fairly rainy morning, then see rain taper off from west to east through the afternoon. Skies will remain cloudy through the day with winds out of the east. Expect a high near 13°C. The low on Thursday night will be around 7°C under mainly cloudy skies.

When all is said and done, it’s possible we’ll see somewhere from 10–20mm of fresh rain, however this entire system may end up shifting slightly further west which would leave the Red River Valley fairly dry until remnant showers pass through on Thursday night. We’ll be sure to keep tabs on things as they develop through the day and update with the most likely outcome later tonight.

Friday will bring a break from the gloomy weather as things clear out through the morning, leaving us with sunshine and a high near 19°C and light winds.

Long Range

This weekend will bring another disturbance through the region that has the potential to produce a significant amount of rainfall – 25–50mm – however there’s still a lot of uncertainty associated with the system and many divergent model solutions at the moment. It will likely be a generally unsettled week at best, and potentially a downright rainy one at worst. Some forecasts are showing some fairly favourable convective parameters on Saturday that would hint towards the first significant thunderstorm day of the year, but a decent capping inversion looks to keep things at bay as long as the current forecasts hold out.

Warmer Weather Returns for the Weekend

The brief cool-down in the wake of a relatively short-lived, but potent storm will come to an end this weekend thanks to another low pressure system moving across the Prairies that will bring a warm front across the province over the next couple days.

Friday
-1°C / -7°C
Mainly cloudy with a chance of flurries

Saturday
7°C / 1°C
Increasingly cloudy & windy

Sunday
7°C / -2°C
Clearing & windy

Today will see cloud moving in through the morning as a weak disturbance moves into western Manitoba. While this system will bring 2–4cm of snow west of the Red River Valley, here in Winnipeg we’ll see just a slight chance of a light flurry or two. Further west in the Red River Valley – near Portage la Prairie S/SE down towards Morden & Winkler – will likely see a bit of light snow today, but no significant accumulations from it. Winds will be around 20km/h or so out of the south and Winnipeg will see a high temperature near –1°C. Skies will clear this evening as temperatures head to a low near –7°C.

Saturday will be a warm but windy day as a warm front moves into the Red River Valley. Temperatures will climb to an above-normal[1] 7°C under increasingly cloudy skies. Winds will pick up fairly early in the day and strengthen out of the south to 40–50km/h.

Saturday Night
1°C
Rain overnight

A low pressure system will track through Manitoba on Saturday night. The biggest impact from this storm will be felt in Central and Northern Manitoba where up to 10cm of snow may fall. Further south, we’ll see an area of rain move across the region beginning early Saturday evening and tapering off sometime mid-overnight.

Generally speaking, somewhere between 2–5mm of rain is likely to fall. Winds will taper off in the evening as the Red River Valley moves into the trough of this system, and then pick up again out of the northwest once the low passes. The wind will likely strengthen to around 40km/h by Sunday morning.

GDPS 12hr. QPF valid 12Z Sunday March 29, 2015
12hr. accumulated precipitation amounts forecasted by the GDPS for Saturday night.

Sunday will see clearing skies and a high once again near 7°C. Winds will remain strong out of the northwest at 40–50km/h into the early afternoon before tapering off.

Long Range

The long-range forecast looks quite nice through the first half of next week. Both Monday & Tuesday look to bring fairly sunny skies and highs somewhere in the 5–10°C range. Things take a bit of a turn mid-week when a low pressure system is forecast to move across the Prairies and potentially bring another snow event to the Red River Valley.


  1. Normal daytime highs for this time of year in Winnipeg are near +3°C.  ↩
IR Satellite Image of Late-March Storm over the Southern Prairies

Winter Storm Slams Manitoba

A potent spring storm is moving into Manitoba today and will likely exit the region known as one of the strongest of the Winter 2014/15 season. This storm has already brought drizzle, rain and freezing rain to southwestern Manitoba & the Red River Valley and will end up delivering the whole wintery mix by the time all is said and done. Environment Canada has issued a swath of heavy snowfall warnings and special weather statements across Manitoba in advance of this system.

Tuesday Night

Tuesday Night
-1°C
Rain changing to snow

Rain will redevelop this evening and persist through much of the overnight period until a cold front pushes through the Red River Valley and switches the precipitation over to snow. Many areas in the Red River Valley will see around 5-10mm of rain. Alongside the switchover to snow, strong northwesterly winds to 40-50km/h with gusts as high as 70km/h will begin to move into the Red River Valley. The combination of falling snow and strong winds, coupled with the temperature dropping below zero overnight after a day of melting, drizzle & rain will likely produce very poor driving conditions with slippery roads & poor visibilities in blowing snow by Wednesday morning.

Wednesday

Wednesday
⇒ -2°C / -11°C
Snow ending in the afternoon; windy

Snow will continue through Wednesday morning before beginning to taper off through the afternoon with a further 5-10cm possible for the City of Winnipeg and the Red River Valley. As mentioned before, the snow will be accompanied by strong northwesterly winds to 40-50km/h which will produce a fair amount of blowing snow as well. Temperatures will drop just barely to -2 or -3°C through the day. Given the relatively mild temperatures, it’s quite likely that as soon as the snow begins to taper off, the blowing snow will too; falling snow will be needed to produce it and it’s unlikely we’ll see much ground-based blowing snow after the fact. Winds will begin to taper off late in the afternoon or in the early evening as the storm moves off into Ontario. Left behind the storm will be partly cloudy skies as temperatures drop to around -11°C.


Storm Update

As expected, many regions across Manitoba saw a significant dump of snow overnight and into this morning. Snowfall totals to 10:30AM CDT across Manitoba are:

Location Snowfall Amount
Winnipeg 5cm
Portage la Prairie 5-10cm
Brandon 6cm
Steinbach 5cm
Dauphin 15-25cm
Rossburn 20cm
McCreary 18cm
Neepawa 15cm
Fisher Branch 15cm
Roblin 14cm
Elkhorn 10cm
Argyle 10cm
Swan River 8cm
Miami 6cm
Morris 2cm

In addition to the heavy snow, many areas through the Red River Valley saw several hours of rain last night. Here in Winnipeg, around 8mm fell overnight, and preliminary reports indicate that similar amounts were seen through much of the Red River Valley. In addition to the snow and rain, very strong winds to 50-60km/h moved into Red River Valley this morning producing blowing snow and helping make sure roads are slick.

The winter weather has wreaked havoc on area infrastructure with numerous accidents on highways as well as complications to power infrastructure with numerous pole fires & power line damage events reported. Many motor-vehicle collisions were reported on Manitoba Highways, with several resulting in sections of Highways 1 and 75 being closed. Two of the more significant ones, pictured above, involved a jackknifed semi-truck collision near Elie and a school bus rollover near Ste. Agathe on Highway 75.

Conditions have begun to improve in the Red River Valley; winds remain strong however with the snow finally moving off into Ontario, much of the blowing snow has stopped. Road conditions will continue to be poor through the remainder of the day, so if you are driving, especially on area highways, be sure to give yourself extra time and be cautious.


Thursday

Thursday
-6°C / -11°C
Partly cloudy

Thursday will be a mainly sunny day – perhaps just a few lingering clouds – with a cool high of just -6°C. Winds will be light, so with the increasingly strong March sun it may not actually feel all that bad outside. Even with the sub-zero temperatures, expect plenty of melting to happen. We head into Thursday night with clear skies and cool off to around -10 or -11°C again overnight, although that could be a couple degrees warmer depending on when cloud cover arrives from…

Friday

Friday
-3°C / -8°C
Mainly cloudy with a chance of light snow

Friday will bring mainly cloudy skies as clouds push in either early Friday morning or late overnight on Thursday thanks to a system rippling through Southern Manitoba from the northwest. It will most likely produce a band of snow through portions of the Parkland, Southwest and into the Western Red River Valley. Under this band, accumulations of 1-2cm look possible at this time. There’s a little uncertainty as to the exact track, given that it’s 3.5 days out at this point, so it may end up a little further west or east. With the current “most likely” track, Winnipeg sees a fairly decent chance at some flurries but little in the way of accumulations. Temperatures will climb to around -3°C with fairly light winds. Friday night looks pleasant with light winds again and a low near -8°C.

Long Range

It’s looking as if another storm is possible on Saturday night as a shortwave tracks across Manitoba.

GDPS 24hr. QPF Forecast valid 12Z Sunday March 29, 2015
The GDPS is forecasting a fair amount of precipitation associated with a significant storm moving through Manitoba this weekend.

Fortunately, it seems like it will be bringing enough warm air with it that precipitation would fall as rain. Either way, though, it looks like we’ll see plenty of cloud and wind this weekend. After a long spell of little in the way of weather, it looks like a typical, more active springtime pattern is setting up!