Tag: Windy

Springtime: Blowin’ in the Wind

Brad Leave a comment

The warmest day of 2014 is on tap for Winnipeg as a low pressure system tracking through the northern Prairies brings with it an unseasonably warm air mass. With the passage of a cold front today we’ll also see strong – potentially near warning level in some areas – winds that will usher in slightly cooler temperatures than we’ve seen the past few days as well as a slight chance for a shower or two. With so much snow left on the ground, however, the big question is exactly how warm will it get?

Wednesday
10°C / 0°C
Partly cloudy; windy later today.

Thursday
7°C / -3°C
Mainly sunny. Winds gradually diminsihing.

Friday
7°C / -6°C
Mainly sunny.

Today

We’re off to a great start today with temperatures already above the freezing mark thanks to the incoming mild air and relatively breezy conditions that persisted through the overnight period. Warmer air will continue to stream in through the morning hours, producing a brisk southerly wind through the valley at 30-40km/h. Temperatures will climb the best they can, but the remaining snowpack will do a lot to keep us cooler.

In order for us to reach the full potential of the warm air coming in, we need to be able to mix it down to the surface. The best way to create instability in the lower levels is the sun; it shines down and warms up the surface until it gets hot enough (assuming the sun is strong enough) to create instability and begin mixing the lower atmosphere. This mixing process can help bring warmer air down and maintain a warmer temperature. Unfortunately, snow can dramatically inhibit this process through two main ways:

  1. Snow is white, so it reflects the incoming energy from the sun back out into the sky. This prevents that energy from being put into warming up the ground or air in the low levels.
  2. Snow is frozen, so when the temperatures begin to climb above zero the snow begins to melt, removing energy from the air and cooling it off.

With no snow, all the energy from the sun can go into heating the surface. Today we’ll see a pretty big difference in temperatures between areas with snow versus areas without snow. Here in Winnipeg, temperatures will likely climb to around 9-10°C before a cold front pushes through this afternoon. In the snow-free areas of North Dakota and a few portions of the western Red River Valley, temperatures will likely climb into the mid-to-high teens, possibly as high as the low 20’s.

Foreast temperatures for this afternoon from the RDPS. Note the warmer temperatures in North Dakota (no snow) and downwind of the western escarpment of the Manitoba Red River Valley.
Foreast temperatures for this afternoon from the RDPS. Note the warmer temperatures in North Dakota (no snow) and downwind of the western escarpment of the Manitoba Red River Valley.

The abnormally warm weather will be short-lived as a cold front blasts through the province midday. Strong westerly to northwesterly winds with gusts as high as 70km/h will push into the Red River Valley this afternoon. Temperatures may actually climb a degree or two behind the cold front before they begin to drop a bit thanks to all the warm air aloft that is able to be mixed down. There will be a slight chance for a shower with the passage of the cold front, however the chances are better to the north of the Red River Valley, where the lift is stronger, and in North Dakota, where the instability is greater. We’ll head to a low of around 0°C tonight.

The Remainder of the Week

Tomorrow will be a mainly sunny day with stronger winds that will slowly diminish as the day progresses eastwards. We’ll see a high near 7°C and a low near -3°C. Friday will be another pleasant day with mainly sunny skies and relatively light winds. The high will be near 7°C and the low will drop to around -6°C as some cooler air makes a brief appearance for the weekend.

March to end with a Bang

Brad Leave a comment

This March not only came in like a lion, it will also go out like a lion. A major winter storm will slam the American Red River Valley and parts of south-eastern Manitoba today. Read on for the details.

A Colorado Low will bring heavy snow to parts of southern Manitoba and the northern United States on Monday
A Colorado Low will bring heavy snow to parts of southern Manitoba and the northern United States on Monday

Monday

Monday
-9°C / -15°C
Snow, heavy in some areas. Windy.

A Colorado Low will bring heavy snow and high winds to the Red River Valley and south-eastern Manitoba today. Wind speeds will range from 40-50km/h gusting to 50-70km/h. Some areas may even see winds as high as 60km/h gusting to 80km/h for a period of time. This will produce blizzard conditions in open areas of the Red River Valley and south-eastern Manitoba. The map below illustrates the expected snowfall totals.

Expected storm-total snowfall amounts.
Expected storm-total snowfall amounts.

Travel will become very difficult, if not impossible from points south of Winnipeg and into the American Red River Valley as the day progresses. Highway closures are likely through the day, with some roadways possibly staying closed until Tuesday. Roads that remain open will be in poor shape as well, so those traveling today may need to reconsider their plans.

This storm will wind down on Tuesday as the snow ends and the wind begins to decrease. However, those areas that saw the heaviest snow will have to deal with large snow drifts on Tuesday. Travel will be difficult if not impossible, particularly in the American Red River Valley, on most of Monday and likely into Tuesday as well. Luckily this storm should signal the beginning of the end of the seemingly endless winter we’ve endured.

Tuesday

Tuesday
-8°C / -22°C
Mainly Sunny

Tuesday will be a much calmer day in southern Manitoba. Temperatures will warm into the minus single digits, but a north-west wind will linger as Monday’s storm departs. At least it will be decent shoveling weather…

Wednesday

Wednesday
-4°C / -18°C
Mainly Sunny

Wednesday will see further improvement over Tuesday, as temperatures climb into the low to mid minus single digits. That should be good enough for some light melting of snow off dark surfaces – melting that can’t come soon enough for most people.

Long Range

The long range forecast is looking good for a change. Most models suggest we’ll see near normal weather in the short to medium term, which means high temperatures in the mid positive single digits. That should help to gradually start wearing down our snow pack.

Windy, Unsettled Weather Marks Pattern Shift

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Windier, snowier weather is on the way for Winnipeg and the Red River Valley, marking the start of a large-scale pattern shift which will bring the latest – and hopefully last – deep freeze to an end and allow more seasonal weather and temperatures to take hold.

Wednesday
-9°C / ⇑ -6°C
Windy & cloudy. Blowing snow possible. Snow in the afternoon.

Thursday
-1°C ⇓ / -18°C
Snow ending midday; breezy with temperatures falling in the afternoon.

Friday
-12°C / -20 to -25°C
Mainly sunny.

A Windy, Snowy Shift

Warmer air trying to build its way into the Red River Valley will result in increasing southerly winds today. By early this afternoon, winds will be quite strong out of the south at 40-50km/h with gusts as high as 70km/h. These strong winds – coupled with a fairly deep boundary layer – will likely produce fairly widespread blowing snow in the Red River Valley. It’s severity may be limited by relatively mild temperatures, however it’s best that anyone travelling on area highways be prepared for poor driving conditions.

Warmer air at 850mb (denoted by the yellow/red colours) will be pushing northeastwards over the next 24 hours.
Warmer air at 850mb (denoted by the yellow/red colours) will be pushing northeastwards over the next 24 hours.

By late in the afternoon, the upper-level portion of the warm front will be approaching the Manitoba border. A strengthening jet[1] overriding the 850mb baroclinic zone will provide a fair amount of isentropic lift. As the jet intensifies, as will the area of light snow pushing into Parkland Manitoba this morning. It will progress eastwards through the day and push through the Interlake and Red River Valley mid-to-late this afternoon.

It seems likely that Winnipeg will see around 2cm of snow that falls as a fairly intense, but short, burst. Areas south of the city will be more hit and miss as to whether or not snow falls. The safe thing to say is that you’re more and more likely to see snow the further north you are in the valley.

By evening our temperature will climb up to our daytime high of about -9°C. Overnight will bring the continued chance for flurries/light snow while winds diminish somewhat and temperatures continue to rise to around -7 or -6°C here in Winnipeg.

Expected storm-total snowfall by Friday morning. Snow will fall in 3 main batches.
Expected storm-total snowfall by Friday morning. Snow will fall in 3 main batches.

Thursday looks to bring more snow to Winnipeg & the Red River Valley as a clipper system races along the Canada-US border. Snow will move in fairly early in the day, spreading eastwards along the Trans-Canada corridor into Winnipeg, and end early in the afternoon. In total, around 5cm is likely to fall through the morning hours – with a little less to the south of Winnipeg – while accompanied by breezy winds out of the south at around 30km/h. Winds will become gusty out of the NW at 30-50km/h in the afternoon as the system tracks off to our east.

Temperatures will climb to a positively balmy -2 or -1°C by midday before the northwesterlies begin drawing in cooler air.

Flurries & Cooler

Thursday night will bring a good chance of seeing some flurry activity as another ridge of high pressure builds in from the NW and some favourable snow-making air slides southeastwards through the region. Any accumulations would amount to only a couple cm at most, and through the night the clouds will break up and we’ll be left with partly cloudy skies by Friday morning.

Friday itself will bring cooler temperatures with a high of only around -12°C and light winds. Some cloud cover Friday night will help temperatures from dipping too much, with overnight lows dipping just below -20°C.

Spring Ahead?

Hope finally lies in the long-range models. Almost all are showing a high probability of a return to seasonal temperatures[2] within the next 2 weeks. No significant cold snaps are in the foreseeable future, and with the sun getting stronger and stronger and the days getting longer and longer, it doesn’t seem likely that we’ll see any more brutal cold snaps for the miserable winter of 2013-2014.

Don’t forget that this coming Sunday, March 9th at 2:00AM we get to do that wonderful[3] tradition of changing our clocks! We spring forward an hour, so it’ll be time to cash in that extra hour you banked way back in the fall!

  1. A “jet” is a narrow ribbon of strong winds aloft.  ↩
  2. Which will be for daytime highs near -3°C and overnight lows near -13°C.  ↩
  3. Awful.  ↩

In Like A Lion

Brad Leave a comment

March will be coming in like a lion as one of the coldest winters in our lifetimes continues on with no end in sight. Some of the coldest temperatures of the season are poised to return as yet another reinforcing blast of Arctic air slumps southwards over the region.

Friday
-19°C / -35°C
Flurries ending midday then clearing and windy.

Saturday
-25°C / -32°C
Sunny & cold.

Sunday
-22°C / -30°C
Sunny.

Flurries Give Way to Deep Freeze

A weak inverted trough moving through Southern Manitoba this morning is spreading flurries across the entire region. The remainder of the snow and cloud will clear out midday as we head to a daytime high of -19°C. Unfortunately, the clearing skies are symptomatic of a brutal blast of Arctic air slumping southwards that will bring us yet another night with overnight lows dipping towards the -35°C range.

850mb temperatures show clearly the next lobe of very cold air slumping into the Southern Prairies.
850mb temperatures show the next lobe of very cold air slumping into the Southern Prairies.

As we move onto the backside of the inverted trough this afternoon, strong northerly winds will move into the region – increasing to 30-40km/h with gusts to 60km/h – and produce localized blowing snow throughout the entire Red River Valley. The situation will resemble the clearing and strong winds we received on Wednesday, however today won’t be as intense as that event.

Winds will taper off this evening alongside our plummeting temperatures as another Arctic ridge of high pressure makes its way into the region. This ridge of high pressure will be driven by a lobe of extremely cold air aloft rotating southwards over the Prairies. Temperatures at 700mb through the core of the cold air is forecast to be in the -35 to -40°C range which puts it as the coldest air in the entirety of the northern hemisphere. This extremely cold air will push our overnight low to around -35°C and combine with winds that will remain around 15km/h to produce extreme wind chill values in the -45 to -50 range.

Sunny and Cold Weekend

Conditions through the rest of the weekend will be benign and cold. Mainly sunny skies will dominate with winds generally between 15-25km/h. Saturday’s daytime high of -25°C will be some 20°C below the seasonal daytime high for this time of year. Sunday will warm to around -21 or -22°C for a daytime high, still well below normal. Overnight lows will dip just below -30°C both nights.

Cold Weather Continues

Unseasonably cold weather will continue through the next week as temperatures very slowly warm. By the end of next week temperatures look to climb back to around -10°C with the chance for a couple of shots of snow through the second half of the week.

The NAEFS 8-14 Day Temperature Outlook
The NAEFS 8-14 Day Temperature Outlook

It does look like this miserable pattern begins to break down next weekend into the following week, allowing more seasonal air to push back into our region. The NAEFS 8-14 day temperature outlook is also picking up on the pattern change and finally showing a return to seasonal temperatures.

So be brave; we only need to make it one more week and what is almost surely the last extreme cold snap of the season will be past. This winter has been brutal and will easily sit in the top 3 coldest winters of the last 100 years. Lets all hope that we can shift into a steadier mild pattern through mid-March and start getting rid of this snow.