Tag: Windy

Showers on Friday, Long Range Shifts To A Nicer Outlook

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A low pressure system and cold front moving through Manitoba today will bring morning showers or thunderstorms to the Red River Valley and a follow-up chance for rain this afternoon. Once this system clears out, there’s good news ahead as the long-range forecast has shifted to a more optimistic outlook!

To start Friday off Winnipeg & the Red River Valley will see cloudy skies with a good chance of showers as a line of precipitation moves into the region from the west. That line should be through by 8 or 9AM, and then Winnipeg will be left with cloudy skies and a breezy southerly wind near 30 gusting to 50 km/h as temperatures climb towards a high near 24°C. Then, around 2-3 PM, the threat for thunderstorms will redevelop — primarily for Winnipeg south to the US border and areas east — as a cold front moves across the region. Strong thunderstorms are likely with this front with the potential for isolated to scattered severe storms. The main threat with this afternoon’s thunderstorms will be large hail between the size of nickels and loonies alongside gusty winds. Things will calm down this evening as the wind swings around to the northwest and temperatures head to a low near 13°C.

PASPC Day 1 Thunderstorm Outlook valid September 1, 2017
The PASPC Thunderstorm Outlook highlights well where severe thunderstorms are possible today.

Late Saturday night into early Sunday morning, it appears a weak disturbance will roll through the region. It will mainly bring a bit of cloud to the region but there will be a small chance of some early morning showers on Saturday. Once it moves out, though, Winnipeg will be set for a beautiful day as weak ridging moves into the area, bringing mainly sunny skies, light winds, and temperatures in the mid-20’s.

GDPS Surface Temperature Forecast valid 21Z Sunday September 3, 2017 with annotations
A low pressure system passing through Manitoba on Sunday will bring warm temperatures to the Red River Valley

Another low pressure system is then forecast to move across the Interlake on Sunday, drawing very warm air eastwards and pushing daytime highs up in into the low 30’s. Winds will be breezy out of the south at 30-40 km/h, and Winnipeg can expect partly cloudy skies. Temperatures will then dip back to around 13°C again on Sunday night with a breezy northwesterly wind.

Long Range

The long-range forecast is looking much better than it appeared it would be earlier this week! While a potent shot of cold air is expected to slide southwards behind Sunday’s system, dropping high temperatures on Monday and Tuesday into the upper teens, the cool weather is now expected to be short-lived. Instead of being stuck on the edge of a large upper-level trough as an upper-level ridge sits over BC, models have moved towards a more progressive pattern, allowing the ridge to push eastwards relatively quickly. This means a return to seasonal temperatures by mid-week instead of week’s end.

Otherwise, fairly quiet weather on tap for next week.

Winnipeg’s seasonal daytime high is currently 21°C while the seasonal overnight low is 9C.

Another Cool, Showery Day Before A Slow Warm-Up

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A shortwave rolling across southern Manitoba today will bring cloudy skies, cool temperatures, and a good chance of more rain showers through the afternoon. The remainder of the week will bring more sunshine and a slow return towards seasonal temperatures.

Extensive cloud moved into southern Manitoba overnight and will persist for much of today as an upper-level disturbance called a shortwave moves through the region. As it swings through, it will likely be supporting an area of showers that will move into the Red River Valley later this morning and move out mid- to late-afternoon. Rainfall amounts will generally fall in the 5-10 mm range throughout the main area of rain in the Red River Valley, however a narrow line of 10-20 mm accumulations may set up somewhere along the path of the shortwave as it moves through the valley.

RDPS 12hr. QPF valid 00Z Wednesday August 23, 2017
An area of showers will produce accumulating rain across a swath of Southern Manitoba today.

The cloud and rain will make for quite a cool day with high temperatures climbing to only the upper teens. Winds will be easterly wind at just 10-20 km/h. The rain and cloud will clear out this evening as a ridge of high pressure moves into southern Manitoba.

Thursday will be a relatively pleasant day when compared to Wednesday; expect mainly sunny skies, winds out of the southeast at 15-25 km/h, and a high near 23°C. Thursday night will continue clear with a low near 12°C.

Friday will bring seasonal temperatures back to the Red River Valley, but a developing low pressure system over the western Prairies will produce gusty southerly winds over the Red River Valley. The day will start off sunny, but become partly cloudy midday with winds increasing to 30-40 km/h out of the south. Highs will be near- to slightly above-seasonal in the mid-20’s.

GDPS 10m Wind Forecast valid 21Z Friday August 25, 2017
An area of breezy southeasterly winds will develop on Friday from Lake Manitoba southeastwards across the Red River Valley into Northern Minnesota.

More cloud cover will move in later in the day as a trough approaches from Saskatchewan. Expect a low in Winnipeg near 15°C on Friday night with winds gradually diminishing.

Long Range

Saturday will bring a cloudy day to the Red River Valley as a trough swings through the region. There will be a slight chance of showers or thundershowers as it moves through. There may be a few sunny breaks late in the day, but expect cloudy skies to return Saturday night with another slight chance of showers or thunderstorms.

Sunday will see things gradually improve with near-seasonal temperatures returning alongside some sunshine. The start to next week looks to bring near to slightly above-seasonal temperatures to Winnipeg with a fair amount of sunshine.

Winnipeg’s seasonal daytime high is currently 24°C while the seasonal overnight low is 11°C.

Warm With A Chance of Thunderstorms, Then Turning Drier

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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. ↩