Tag: Windy

Warm With A Chance of Thunderstorms, Then Turning Drier

Brad Leave a comment

The weather returns to slightly warmer than normal summer fare for Winnipeg to start the week with highs in the upper 20’s and mild lows. It will also be relatively dry, with the only significant chance for rain coming on Monday night as a cold front slowly moves through the Red River Valley.

Today will be a warm and windy day in Winnipeg as breezy southerlies bring summer heat and slightly muggy conditions to the Red River Valley. Skies will become mixed fairly early in the morning as the south-to-southeasterly winds ramp up to 30-40 km/h. These gusty southerly winds will bring mild temperatures into the region, pushing daytime highs just short of 30°C. In addition to the warmth, these winds will maintain the slightly humid conditions in place with dew points remaining in the 16-18°C range. Closer to the cold front — primarily over the southwestern corner of the province but also possibly into the western Red River Valley — moisture will pool and dew points will likely rise into the low 20’s, making for quite a muggy day in those areas.

A potent low pressure system over western Saskatchewan will spread gusty southerly winds across the Red River Valley on Monday afternoon.

By evening, a cold front will be pushing eastwards into the Red River Valley, bringing with it a chance of showers or thunderstorms to much of southern Manitoba.

Going over the MIST ingredients:

  • Moisture: Dew points will climb generally into the mid-teens, but elevated moisture is expected near the cold front as moderate southerly winds enhance moisture pooling ahead of the front. Moisture is also expected to be moderately deep, extending to roughly 850 mb.
  • Instability: Moderate mid-level lapse rates on the order of 7-8°C/km will combine with the low-level moisture to produce MLCAPE values of 1500-2000 J/kg.
  • Shear: Shear will be somewhat lacking with only 25-30 kt of 0-6 km bulk shear; this is fairly low and may be the real limiting factor in any thunderstorm activity that may develop.
  • Trigger: A pronounced cold frontal trough moving eastwards will provide the focus for any convective development.

Overall it seems that there will be enough energy available for severe thunderstorms, but the lack of shear will throw a wrench into the certainty of a large-scale severe weather outbreak.

The highest risk for severe weather in southern Manitoba will be over the southwestern corner where scattered thunderstorms first fire up along the cold front. These storms will have the potential to produce significant hail and strong winds. While an isolated tornado is possible, it won’t be an elevated threat with today’s thunderstorms. As the cold front moves eastwards through the evening and spreads the thunderstorm threat into the Red River Valley, the threat shifts towards favouring strong winds. Temperatures will bottom out overnight around 18-19°C with the winds tapering off.

This simulated RADAR image from the 3km NAM model shows a forecast of thunderstorms for the Red River Valley on Monday evening.

The weather then settles for Tuesday and Wednesday as a broad ridge of high pressure builds into the Prairies. Skies will clear and remain mainly sunny for much of Tuesday and Wednesday as temperatures climb to highs near 27°C both days. It will remain slightly humid with dew points remaining in the mid-teens through the middle of the week. With that humidity remaining in the region, it will keep overnight lows in the mid-teens as well.

Long Range

Gradual upper-level ridging will build into the Prairies late this week and into early next week, bringing continued mild weather and low probabilities of rain. The odd system may slide across southern Manitoba from the northwest, returning temperatures back to seasonal alongside a chance of showers. Overall, though, it appears Winnipeg and the Red River Valley will be entering into a fairly dry pattern.

Winnipeg’s seasonal daytime high is currently 26°C while the seasonal overnight low is 13°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. ↩

One More Damp Day, Then May Ends With Nicer Weather

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Winnipeg will be under the influence of the storm system that has been bringing showers to southern Manitoba the past couple days for one more yet, but then a return to more pleasant weather will quickly return for the end of May!

More showers are on the way for Winnipeg today as moisture continues to stream southwards through the province on the back-side of the storm system that moved through over the weekend. Breezy northwesterly winds of 30 gusting 50 km/h will make today’s high of just 11°C feel rather dreary. The chance for showers will continue tonight, although it won’t be quite as likely, as temperatures drop to a low near 6°C.

More showers are expected across much of Manitoba today and tonight.

Sunshine will return to Winnipeg on Tuesday as skies clear for the afternoon. There will be a slight chance of showers in the morning as one more little disturbance ripples through, but as skies clear midday temperatures will warm up to a high near 18°C. The wind will continue to be gusty out of the northwest, but the sunshine should make for a much more pleasant afternoon. Skies will completely clear out by evening as winds taper off and Winnipeg heads to a low near 8°C.

Wednesday will be a beautiful day to end the month on; sunny skies with a high near 24°C are on the way with light winds of just 10-20 km/h out of the west. The low will be relatively mild on Wednesday night at around 10°C.

Long Range

The remainder of the work week looks pleasant with continued sunny to mixed skies and highs in the low 20’s. A system will approach Manitoba on Friday, but at the moment guidance suggests it will remain to the south and west. There is general agreement that next week may turn more unsettled once again, so we’ll be keeping an eye on that as the week progresses.

Winnipeg’s seasonal daytime high is currently 22°C while the seasonal overnight low is 8°C.

Mixed Bag For Second Half of the Work Week

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Winnipeg will dodge the worst of a major storm system that will slam Alberta and portions of Saskatchewan with strong winds and rain; comparatively, things will be quite pleasant!

A major storm is developing over Alberta today that will bring 30-50 mm of rain to the province alongside winds gusting over 100 km/h. This system will spread eastwards and bring significant weather to Saskatchewan later today, but will begin to weaken as it approaches Manitoba overnight. While Winnipeg will be spared from the brunt of this storm, some breezy and unsettled weather is still on the horizon.

First up, today will be a warm and windy day as moderate southerlies develop ahead of the Alberta storm. We should see fairly sunny skies, but winds will pick up out of the south-southeast to 30-40 km/h with gusts to 60 km/h through the morning and early afternoon. Temperatures will be near-seasonal with a high of 21°C.

The winds will continue out of the south-southeast tonight at around 30 gusting 50 km/h as cloud cover pushes in late overnight. Temperatures will drop to a low near 11°C.

Thursday will bring cloudy skies to the region as a trowal1 moves through the region. Whether or not Winnipeg will see rain is still somewhat uncertain; support for it definitely tapers off as the feature moves into the Red River Valley, but it will likely be able to sustain a band of rain or showers that will move through mid-day. A second batch of showers is possible in the early evening as the low pressure system moves into the Interlake.

More recent model runs are beginning to show accumulating rainfall in the Red River Valley on Thursday

While the winds will be breezy first thing, they should diminish through the morning as the low approaches. Temperatures will reach a high near 18°C. Temperatures should dip to around 12°C on Thursday night with the cloud cover breaking up.

Friday will bring mixed skies to Winnipeg & the Red River valley with a high near 19°C. It should stay dry, with any showers to our east and north. Winds will be out of the west at 15-25 km/h. It looks like skies should be fairly clear on Friday night as temperatures dip to a low near 9°C.

Long Range

The mixed bag continues this weekend with Saturday likely bringing a fair amount of sunshine and highs near the 20°C mark, but things take a turn on Sunday with highs dropping into the mid-teens as showers slump southwards out of northern Manitoba. With breezy northwesterly winds, it will likely be a relatively unpleasant day. The unsettled weather may persist into Monday, but then the remainder of next week looks pleasant with dry conditions and highs in the low 20’s.

Winnipeg’s seasonal daytime high is currently 21°C while the seasonal overnight low is 7°C.

  1. Trowal stands for “trough of warm air aloft” and is the warm air rising around a low pressure system from the occluding frontal wave. ↩