Tag: Thunderstorms

Stormy Tuesday Brings The Heat

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The heat will be cranking up over the Prairies this week, and Winnipeg will see increasing warmth through the start of the week. A potentially stormy Tuesday will be a marked turning point as hot and muggy weather moves into the region. Heading into the second half of the week, conditions will be more settled but the heat sticks around for the foreseeable future.

A major pattern shift is underway that will bring a prolonged period of heat to much of western North America. Winnipeg will begin feeling the impact today as temperatures climb towards a high of 27°C under mixed skies. Winds will pick up out of the south-southeast to around 20 km/h in the afternoon as low pressure system begins approaching the province from Saskatchewan. The humidity will remain relatively comfortable today, though, with dew point temperatures expected to remain around 13 or 14°C.1

Winds will continue out of the south-southeast tonight with temperatures remaining warm overnight; the expected low is just 17°C as a warm front pushes across the Red River Valley.

The RDPS shows an organized line of thunderstorms developing on Tuesday afternoon.

Summer will arrive in all forms for Winnipeg on Tuesday. Now in what’s known as the warm sector, the humidity will rise quite quickly on Tuesday morning with dew points reaching around 18-19°C. Temperatures will climb towards a high of 29°C which will feel closer to the mid-30’s with the humidity factored in. For the afternoon, attention will turn towards the potential for severe thunderstorms as a cold front pushes southeastwards into the Red River Valley.

Going over the MIST ingredients:

  • Moisture: Plenty of moisture available with dew points in the upper teens being fed into any storms that develop. Moisture also seems to be relatively deep, so dramatic reductions due to mixing are unlikely.
  • Instability: MLCAPE values climb towards the 2000 J/kg mark with marginal capping. The low-level inversion will erode with the injection of 850 mb cooling while 700 mb temperatures remain below the 10°C threshold.
  • Shear: Surface – 6km bulk shear values peak around 30 kt which would be ample for storm organization.
  • Trigger: Two primary foci for convection: a pre-frontal trough that moves through midday, and then a cold front that pushes into the region mid- to late-afternoon.

These thunderstorms may be severe with the primary threats being large hail and localized flooding due to intense downpours. Strong wind gusts are possible with these storms as well. At this point, it seems like a tornado threat is unlikely, but we’ll keep an eye on things as they develop.

After the cold front slides through, winds will shift out of the northwest at around 15-25 km/h and the humidity will begin to ease as drier air moves into the region. Temperature will still remain warm, though, with overnight lows dropping only to around the 17°C mark once again.

Wednesday will be another hot day with temperatures climbing to around the 28°C mark with partly cloudy skies in the morning. The humidity will be much more comfortable than on Tuesday thanks to drier air that works in through the day and drops dew points back down to the low teens for the afternoon. Expect a low near 17 or 18°C on Wednesday night with a slight chance of another shower or thunderstorm as a weak disturbance slides through the region.

Long Range.

Looking further ahead, temperatures will cool towards seasonal to round out the work week as slightly cooler air moves in behind Wednesday night’s disturbance.

NAEFS 8-14 Day Temperature Anomaly Forecast — Valid July 10 – 17, 2017

The heat begins building back in through the weekend, and next week is looking quite warm and relatively humid as an upper ridge builds over the western Prairies, spreading above-normal temperatures across the region.

Winnipeg’s seasonal daytime high is currently 25°C while the seasonal overnight low is 13°C.

  1. The dew point only begins having a significant impact on how hot and/or muggy it feels once it begins climbing above 15°C or so. ↩

Unsettled & Cooler…Again

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Another disturbance tracking across the Prairies will bring more wet weather to Winnipeg and keep temperatures cooler than seasonal for late June.

Today will start off with a line of showers and/or thunderstorms moving eastwards through the Red River Valley as a cold front pushes eastwards across the region. General rainfall amounts within the Red River Valley from this system will be around the 5-10 mm mark, although locally higher amounts are possible in thunderstorms. That said, it’s likely that the eastern Red River Valley sees higher amounts while the western Red River Valley trends towards lower amounts. Depending on exactly how things have evolved overnight, though, there may be sizeable gaps in the line of precipitation resulting in some areas seeing no rain at all.

The wet and stormy weather will clear out of the valley midday, and Winnipeg will be left with gradually clearing skies into the evening. Temperatures will climb to high near 22°C this afternoon with winds picking up out of the northwest to 20-30 km/h behind the cold frontal passage.

Winnipeg will be on the western edge of tomorrow’s rain, with much of it falling to the east and north of the Red River Valley.

Winnipeg should see fairly clear skies tonight with light winds as temperatures dip to a low near 13°C.

Thursday will likely begin with some sunshine, but quickly cloud up in the morning as another low pressure system begins moving into the area. Any wet weather should hold off until mid-to-late afternoon; heading towards evening it looks likely that another batch of scattered showers or thunderstorms will develop. With the wet weather holding off until later in the day, it will actually be relatively pleasant despite the cloudy skies with temperatures climbing to a high near 22°C and light winds.

Scattered showers will likely continue across the Red River Valley on Thursday night, supported by a cold low stalled over the region. Temperatures will head to a low near 14°C.

A deep upper trough with cold low embedded will be in place over Manitoba on Friday.

Friday will bring mainly cloudy skies and scattered showers or thundershowers to Winnipeg and the Red River Valley. Temperatures will be cooler as a cold low stalls over the region; daytime highs throughout the Red River Valley will be just 19-20°C. Winds will be light out of the north at 10-20 km/h.

Long Range

Canada’s 150th anniversary celebrations are looking okay at this point; cloudy skies in the morning should gradually clear through the day, although we may see a few light showers through the first half of the day. Temperatures will climb to a high near 21-22°C with winds out of the north at 10-20 km/h. For the evening celebrations, skies should be mixed or partly cloudy with temperatures somewhere in the 15-20°C range.

Sunday will be a pleasant day with partly cloudy skies and a high near 23°C. Heading into next week it looks like we’ll finally snap out of this cool spell and see some seasonal to above-seasonal temperatures build in for the week!

Winnipeg’s seasonal daytime high is currently 25°C while the seasonal overnight low is 12°C.

Seasonal Temperatures Build Back, But Quick Return to Unsettled Conditions

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In what is quickly becoming the summer that just can’t quite get going, seasonal warmth will be ushered out of the region by unsettled conditions nearly as quickly as it arrives as another large low pressure system moves into the Prairies.

Winnipeg will see a return to more seasonal temperatures today as the weather system that had brought the cooler temperatures moves off to the east. Today will be perhaps the most pleasant of the next few as sunny skies will combine with light winds and a high near 22°C. Expect temperatures to dip down to around 10°C tonight with some cloud cover moving into the region near morning.

Tomorrow will bring slightly warmer temperatures alongside breezy southeasterly winds that pick up to around 30 gusting 50 km/h. The increasing warmth and wind is thanks to a trough of low pressure pushing eastwards across the Prairies associated with an upper low moving out of Alberta. Winnipeg will see a daytime high climb towards 24°C with mixed to cloudy skies for much of the day, although it’s likely that we’ll see a few sunny breaks in the afternoon. Temperatures will dip to a low near 15°C on Tuesday night under cloudy skies with an increasing chance of rain towards morning.

A band of showers and thunderstorms will push across southwestern Manitoba towards the Red River Valley early Wednesady morning
A band of showers and thunderstorms will push across southwestern Manitoba towards the Red River Valley early Wednesady morning

Wednesday will bring the low pressure system through Manitoba, spreading showers and/or thunderstorms throughout the region, primarily through the morning hours. After that Winnipeg will be left with cloudy skies and a slight chance of showers. Temperatures will reach a high near 19°C with cloudy skies continuing on Wednesday night as the low drops to around 14°C.

Long Range

The unsettled weather continues for the second half of the work week. Slightly cooler-than-seasonal temperatures will beg in place right through the weekend with highs generally in the low 20’s and overnight lows near 10-12°C.

It won’t be soaking wet, but Winnipeg will see a chance of showers late Thursday, much of Friday, and on Canada Day Saturday as well. None of these days look like particularly large soakings or anything of that sort, just generally unsettled conditions.

Winnipeg’s seasonal daytime high is currently 25°C while the seasonal overnight low is 12°C.

A Return to Unsettled Weather

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After an all-too-brief respite from the wet conditions of the past week, more chances for rain are on the way as a series of disturbances move through southern Manitoba.

The rain train is heading back to Winnipeg Station today as an occluding frontal wave moves across the southern portion of the province ahead of a deepening low pressure system. As the wave approaches this morning, mostly cloudy skies will be in place and there is a chance that some morning showers will materialize.1 The main action — a mix of showers and thunderstorms — will begin developing near midday over southwestern Manitoba and then quickly expand and move eastwards into the Red River Valley for the afternoon. These will move out of the region by the early evening.

Severe thunderstorms are not expected over a widespread area, however there are just enough energetics and dynamics that an isolated storm or two may become marginally severe.2

Showers and thunderstorms are expected across much of the Red River Valley, Interlake and points eastwards today.

Temperatures will climb to a high near 21 or 22°C today with southerly winds of 30-40 km/h gusting up to 60 km/h shifting to westerly after the frontal passage in the afternoon. Expect some clearing in the evening, then variable cloudiness developing towards morning. Temperatures will dip down to a low near 13°C.

Thursday will bring mixed to mostly cloudy skies to Winnipeg and much of the Red River Valley as strong westerly winds of 40-50 km/h build into the region. There will be a chance of showers as rain wraps around on the back side of the passing low pressure system, but much of the guidance suggests that the rain will remain mainly north of the Red River Valley. Temperatures will climb to a high near 19°C and head towards a low near 12°C under mostly cloudy skies with light rain likely on Thursday night.

An area of light rain/showers will slump southwards through the Interlake into the northern Red River Valley on Thursday night.

Friday will bring cloudy skies with a chance of showers as the overnight activity on Thursday tapers off through the region as an upper-level trough exits. Winds will be out of the northwest at 30-40 km/h with gusts up into the 50-60 km/h range. Skies continue cloudy overnight with a chance of showers as temperatures drop to a low near 10°C.

Long Range

Saturday will remain unsettled with a chance of showers as a weak disturbance ripples through the region from the north and cooler air spills southwards. Conditions finally improve on Sunday, which looks likely to be a fairly sunny day. Temperatures will remain below normal, however, through the weekend and into early next week as Manitoba remains under the influence of a large upper low over Hudson Bay.

Winnipeg’s seasonal daytime high is currently 24°C while the seasonal overnight low is 12°C.

  1. These showers would be elevated, meaning they are formed at higher altitudes and would occur ahead of the incoming front. ↩
  2. In this case, we would expect either wind gusts just over 90 km/h or severe hail in the 20-25mm range. ↩