Sunny Week Ahead; Potentially Stormy End To The Weekend

Brad Leave a comment

The remainder of this week will be filled with sun as yet another Arctic ridge dominates over the Eastern Prairies, continuing the unshakable grasp of winter. While temperatures will be milder compared to the first half of the week, we’ll reamain well below our normal of around +9°C but with the milder temperatures the sun should be able to continue slowly melting the snow we have. Unfortunately, it’s looking like a fairly significant storm may bring another shot of winter.

This Week

Wednesday

0°C / -14°C
Sunny
Thursday

2°C / -10°C
Sunny
Friday

4°C / -8°C
Mainly sunny; increasing cloudiness in the evening.

A significant Arctic high pressure system will lay dominant over the Eastern Prairies over the next few days with the main ridge axis running from near Churchill towards southwestern Manitoba. We’ll see temperatures slowly climb over the next few days, but our daytime highs will likely remain in the 0-4°C range, although any areas in the city that have managed to become mostly snow-free may get a little warmer than that. Regions outside the City of Winnipeg will likely top out within that range. Perhaps most significantly will be the warming of our overnight lows, which will be in the low minus teens this mronign and move into the minus single digits by the end of the week.

We’ll have plenty of sunshine over the next few days with some clouds starting to work their way into the Red River Valley on Friday night associated with a weakening system pushing through Saskatchewan.

The Weekend

GDPS 24 Hour Precipiation Accumulation valid Monday morning.

24hr. precipitation accumulation valid Monday morning from the GDPS. Current forecast shows the potential for up to 25mm of liquid equivalent precipitaiton.

Saturday looks to be a mix of sun and cloud, but Sunday will be quite an interesting day weather-wise as a Wyoming low pushes northeastwards into southern North Dakota through the day. While the morning looks to start off cloudy, the GDPS1 deepens the low significantly through the afternoon, spreading precipitation northwards into Southern Manitoba. There’s still plenty of time and uncertainty, but this system (at the moment) looks like it could end up producing as much as 15cm of snow. How much actually accumulates will vary highly, since temperatures are expected to be right near 0°C and non-snow-covered surfaces will likely melt much of the snow on contact for the first several hours of the event. There’s also the possibility enough warm air will wrap north of the system that some of the precipitation will fall as rain instead of snow. This system would impact us through Monday as well given the current model output. We’ll keep our eyes on the development of this system; stay tuned.

  1. Global Deterministic Prediction System ↩

Cool and Calm

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Monday through Wednesday

This week will start out cool and calm weather-wise. No significant precipitation or warm weather is expected.

Monday
image
Clearing
-6°C / -21°C
Tuesday
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Mainly sunny
-1°C / -10°C
Wednesday
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Mainly sunny
-1°C / -10°C

Monday will be another ugly April day. Temperatures will be in the mid minus single digits with clearing skies. There will be a strong north wind as well, making it feel even worse than the temperature alone would indicate.

Tuesday and Wednesday will be very similar days. High temperatures will be just below zero in both cases, with the exception of urban and forested regions which will be a few degrees warmer than everyone else. The wind will also be from the north on both Tuesday and Wednesday, but it won’t be very noticeable except in open areas.

Long Range

The long range is looking slightly better than it has been for the last while. It looks like we may finally be moving into a pattern with more consistent melting temperatures by week’s end. It’s too early to say how warm it will get, but it looks like temperatures will still generally remain mainly below normal in the medium-term. The normal high for this time of year is +8C.

Elsewhere in Weather News: April 6th, 2013

Matthieu Leave a comment

Historic Flooding in Argentina

Major cleanup efforts are underway in Argentina this weekend after major flooding occurred in the city of La Plata (pop. 250,000), just east of Buenos Aires. In some areas of La Plata, over 150mm fell in less than a 24 hour period causing for some flash flooding when the city’s sewers simply could not keep up. The reason for so much rain over one area can be attributed to a nearly stationary low pressure system over Argentina, south-west of Buenos Aires. Moist air from the South Atlantic was drawn in and the near stationary thunderstorms stayed over La Plata for over ten hours, beginning April 1st, lasting through April 2nd.

La Plata flooding

Aerial image of one of La Plata’s hardest hit areas. (Source: Reuters)

Flooding caused whole neighbourhoods to be submerged and people had to escape from their houses through the roof as floodwaters rose up to three feet. At one point, three million people were without power across Argentina because of the heavy rains. Some 2,200 residents of La Plata had to be evacuated. Unfortunately, 54 people have died from this event and there are still around 20 people missing. The property damage is extensive and is still being calculated but is likely to be in the hundreds of millions.

Elsewhere around the world:

  • There has also been severe flooding in Eastern China and Taiwan due a series of low pressure systems that brought heavy rain to an already saturated soil base.

  • This week will likely bring another multi-day, severe weather outbreak in the southern half of the US; from the Southern Plains into Dixie Alley, as a large trough digs across the region and warm, moist air from the Gulf of Mexico clashes with it.

More Snow on the Way

Brad Leave a comment

sigh

image

850mb wind forecast showing the deep southerly flow that will be providing the moisture and lift for today’s system.

Today

image
0°C / -2°C
Snow beginning this afternoon. 2-4cm overnight.

A frontal wave sliding across the Prairies will push into Southern Manitoba this morning, spreading snow eastwards across the Red River Valley this afternoon. While southwestern Manitoba will see 5–10cm of the white stuff, we should fare a little better here in the RRV with 5cm expected near the US border tapering off to 2–4cm here in Winnipeg. The bulk of the snow will fall this evening into the overnight period before tapering off late overnight or early tomorrow morning.

Saturday & Sunday

Saturday
image
1°C / -11°C
Cloudy with a chance of flurries. Clearing late in the day.
Sunday
image
-4°C / -14°C
Increasing cloud. Light snow beginning in the afternoon.

Saturday will be a bit of a mixed bag with some lingering flurries in the morning and gradual clearing in the afternoon before skies clear late in the afternoon or evening. The high temperature on Saturday should be around 1°C and we’ll see temperatures drop to –11 or –12°C Saturday night.

More snow looks to be on the way for Sunday afternoon as an Alberta Clipper slides along the international border. At this point, it doesn’t look like a significant system, but it should pack enough of a punch that it will likely drop a couple cm through the RRV in the afternoon. After Sunday, it looks like we’ll slip back into another benign pattern with below-normal temperatures as a surface ridge keeps snowier weather to our west and to our south.