Cool and Calm

The weather this week will be cool and calm, meaning no big weather makers are in the forecast.

Early Week

Monday

Mix of Sun and Cloud. Slight Chance of Flurries.
4°C / -1°C
Tuesday

Mainly Cloudy
2°C / -8°C
Wednesday

Mainly Sunny
0°C / -8°C

Monday will be a seasonably warm day in Southern Manitoba. A cold front will pass through in the morning, causing the wind to shift to westerly. Temperatures will be in the low to mid single digits.

Tuesday should see seasonable conditions continue in Southern Manitoba. Temperatures will be in the low single digits with a light westerly wind.

Wednesday will be very similar to Tuesday, with temperatures once again in the low single digits and winds being light.

Long Range

The long-range forecast looks to feature mostly seasonal weather. However, we’ll likely see our first snowfall of this fall at some point in the next 5-10 days. It probably won’t be a significant snowfall, but a snowfall nonetheless.

Seasonal Weather Ahead; Unsettled Pattern Developing

We’ll see a reprieve from the cold snap across Southern Manitoba over the next few days as temperatures return to more seasonal values, however with that comes the development of a more unsettled pattern that will bring multiple chances for rain or snow to the region over the next week.

Wednesday

6°C / -1°C
Warming up with a few clouds.
Thursday

7°C / -1°C
Mostly cloudy.
Friday

6°C / -2°C
Light snow changing to rain likely.

We’ll see a comparatively beautiful day today with temperatures climbing up to around 6°C under a mix of sun and cloud. The warmer temperatures are thanks to a breakdown of the high-amplitude jet stream that has been in place over North America over the past week and a bit. As the pattern flattens out, it will allow warmer air to push back into Southern Manitoba, which in turn allows us to enjoy non-freezing temperatures. The milder temperatures will stay with us through the remainder of the week.

Thursday (Halloween!) will bring cloudier weather as a weak front aloft begins moving into the area. Temperatures will climb up to around 7°C by the afternoon, making it the warmest day we’ll see this week. Cloudy skies will persist through the night as we drop to around –1°C. Things look to stay nice and dry for the trick or treaters!

Precipitation accumulation expected through the day on Friday, courtesy the NAM.
Precipitation accumulation expected through the day on Friday, courtesy the NAM.

Friday has a good chance of bringing us some light snow or rain. There’s good agreement that a disturbance will slide down from the northwest on Thursday night, pushing into the Red River Valley through the morning hours on Friday. Precipitation may begin as light snow, but should switch over to rain by midday at the latest. No significant amounts are expected; models are only producing a 2–5 mm water-equivalent of precipitation, so it will be relatively light activity. The precipitation looks to move in fairly early in the morning and will last through much of the day before tapering off around supper time or shortly thereafter. We’ll see a high of around 4 or 5°C and an overnight low of around –2°C.

The Weekend Ahead

Cloudy skies will persist through much of the weekend as a more unsettled pattern develops. Daytime highs look to stick around the low single-digits and overnight lows dropping to a couple degrees below zero. The next chance for precipitation looks to push in on Sunday night through Monday as a system pushes through the region bringing snow to the Interlake and possibly areas further south as well. More on that later in the week.

Elsewhere in Weather News: October 5th, 2013

Quadruple threat in the US this Week

All kinds of extreme weather have been plaguing the United States this week; from tropical storms, tornadoes to blizzards to severe Santa Ana winds, they’ve just about seen it all. It was all happening yesterday due to a dynamic low pressure system centered in the Northern US Plains. High pressure building behind the low pressure system was responsible for the Santa Ana winds. The tropical storm, a completely separate system, has been targeting the gulf shores for a few days now.

The powerful fall low pressure system was drawing in brisk air from the north behind it which helped produce ideal conditions for blizzard conditions in the Black Hills. It was not unusual to see snowfall rates in excess of 5cm/h throughout the day on Friday in the region. The hardest hit area in regards to snow looked to be Lead, SD, which by Friday night had received 110cm (in less than 48 hours!), and another 20-30cm could fall before deformation zone moves off.

Lead, SD snow

Streetcam picture of the snow accumulated in Lead, SD. Keep in mind there was no snow on the ground less than 48 hours ago! (Source: Twitter: @TylerJRoney)

Deadwood, SD snow drifts

Incredible image of a large snow drift almost completely covering the front door in Deadwood, SD. (Source: Twitter: @ReadingReineke)

In the warm sector of the same system severe thunderstorms were spawned on Friday. A few supercells formed in the late afternoon near the triple point in northern Nebraska/extreme southern South Dakota. With extremely favourable conditions for tornadoes, storms quickly started rotating. The number of tornadoes is still unclear at this time but a violent, long tracked, wedge tornado which was reported to be over a mile wide, touched down. Per initial reports it appears as though Wayne, NE was the hardest hit on Friday by this tornado. Houses and factories were completely demolished and two dozen people were reported injured. A squall line also evolved further south into Kansas and Oklahoma where large hail and severe wind were the main threats.

Wayne, NE damage

Damage of a factory destroyed in Wayne, NE from the tornado that hit the town. (Source: Twitter: @action3news)

The Santa Ana winds have been a treat to California this week, too. These winds get funneled through the Mountains of Southern California, subsequently warm and dry as they descend in elevation. Gusts in excess of 110km/h have been tearing through Southern California bringing with them an extreme fire risk. This prompted the National Weather Service (NWS) to issue multiple red flag warnings for the area – these warnings are issued when conditions are ideal for wildfires and quick intensification. The NWS also added that these were the worst winds in five years.

As for the tropical storm (Karen) spinning in the Gulf of Mexico, it does not appear that it will become a significant hurricane. Strong wind shear has been affecting its development for the past few days. It will likely make landfall as a tropical storm with winds of tropical storm force, but possibly even weaker depending on how much the shear tears the storm apart. The location of the landfall looks to be on the south-east gulf shores of Louisiana. It doesn’t appear as though its effects will be too significant to the US – heavy rain will be the main threat with Karen. Otherwise, the tropics continue to remain unusually calm and no other developments elsewhere in the Atlantic basin are expected in the near future.

Elsewhere in Weather News: May 4th, 2013

Let it Snow!

Record-setting snowstorms were the topic of conversation in parts of the US this week.

Snowfall reports

Snowfall map until Thursday morning. (Source: NOAA)

Springtime weather was delayed once again as a significant trough moved across Central US dragging down unseasonably cold arctic air with it. Friday morning, temperatures at 850mb reached below freezing all the way down to Mexico; and snow fell from Northern Ontario all the way down to northern parts of Arkansas and Oklahoma! Many snowfall records were shattered, some of the most significant being:

  • Britt, Iowa – Achieved a snow depth of 28cm, beating the old record of 25cm (in 1947).
  • Chippewa-Falls/Eau Claire, Wisconsin – Recorded a snowfall of 22cm shattering the old record of 5cm (in 1946).
  • Extreme north-west Wisconsin – Recorded a snowfall of 46cm.

The trough will not make it to the East Coast as the main jet stream is retreating north and a cutoff low will form in southern US. This cutoff low is expected to slowly drift across the region feeding into tropical moisture while dropping significant rainfall over parts of the south-east and east-central US. Accumulations of over 80mm are expected, increasing concerns that flash floods might be a problem over the weekend.

In other news, a category one cyclone formed off the north-eastern coast of Australia, however it had minimal impacts on land as it fizzled out and only brought lowland flooding and erosion to coastal areas.

Italy also saw an active week with a large tornado reported in it’s northern region. An approaching shortwave combined with significant instability and sufficient shear on Friday was the cause for severe storms in the area.

Short video of the Italian tornado as seen from the nearby city of Castelfranco Emilia. (Source: R. Melotti)