Tag: Thunderstorms

Rain, Rain, Go Away

Scott Leave a comment

More rain is on the way to Southern Manitoba this week thanks to the development of a significant low pressure system through Saskatchewan & North Dakota, but we should squeeze in one more day of nice weather before it arrives.

This Week

Today will be the last decent day before another unsettled pattern builds in as temperatures reach the mid twenties under mainly sunny skies. We’ll be located north of a sharp warm front, causing our winds to be gusty out of the north-east through the day. Cloud cover will likely begin to roll in late in the afternoon or evening, signalling the end of the nice weather. Overnight rain and thunderstorms from North Dakota will lift into southern Manitoba, ushering in more unsettled weather for the next couple days. Overnight rainfall amounts will be difficult to pin down, but 5-15 mm seems probable in most areas, with locally higher amounts in the more intense cells.

Today will be warm and breezy as we sit north of a warm front
Today will be warm and breezy as we sit north of a warm front

Tuesday will see rain ending in the morning, before drier conditions move in for midday. It appears possible that more showers and thunderstorms will develop in the afternoon, especially if there are some breaks in the cloud to allow for daytime heating. Additional rainfall will be sporadic with isolated patches of moderate amounts in showers and thunderstorms. Winds in the Red River Valley are expected to be southerly near 20 km/h.

A cold front will pass through southern Manitoba by Wednesday morning, allowing cooler air to filter down from the north. High temperatures will only be in the mid teens under mainly cloudy skies. Additional showers are likely through the day on Wednesday, but large accumulations are not expected. Winds will be gusty from the north-west at 30 km/h gusting to 50 km/h.

Long Range

It appears that we will return to a warmer pattern by the end of the week. However, models also hint at numerous chances for storms in an unsettled northwesterly flow 5-10 days from now. Temperatures will likely be near or slightly above seasonal during this time period, although some cool downs will likely be interspersed within the warmer periods.

Winnipeg’s Weather Takes A Wet & Unsettled Turn

Brad Leave a comment

A series of disturbances are set to track into Southern Manitoba through the remainder of the week, brining numerous chances for showers & thunderstorms to the region over the coming days.

Today will start with some sunshine for Winnipeg, but as the day progresses skies will become increasingly cloudy as a disturbance pushes northwards out of North Dakota. Before the sun is hidden away behind the cloud, Winnipeg will reach a warm daytime high near 24°C. By mid-afternoon, showers and/or thunderstorms will be pushing northwards through the Red River Valley, likely reaching Winnipeg for the evening rush hour.

Forecast 500mb Vorticity form the GDPS valid Thursday morning
A complex series of upper disturbances will move through Southern Manitoba through the remainder of the week.

The rainy weather will continue overnight and into Thursday, gradually tapering off by Thursday evening. Expect a low near 14°C tonight, a high near 18°C on Thursday, and a low near 12°C on Thursday night.

The sun should make an appearance again on Friday, returning daytime highs back to the mid-20's. There will be a chance for some showers or an isolated thundershower on Friday afternoon. A weak disturbance moving into the region on Friday night will once again bring the chance for more rain on Friday night.

By the time all is said and done, a fair amount of rain is possible over the coming days throughout the Red River Valley. In general, it's likely that most places will see somewhere between 10-30 mm of rain over the coming 3 days, however with the convective nature of some of the precipitation, it's possible that some areas exceed these amounts and end up closer to the 50 mm mark. Where that may be will depend on exactly how this system sets up, so we'll keep an eye on it and provide updates in the comments below.

Long Range

The unsettled weather will continue into the weekend as a couple more disturbances move through the region. Both Saturday and Sunday show a chance of precipitation for the Red River Valley. Daytime highs will be in the low-to-mid 20's once again.

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

Nice End to the Long Weekend

Scott Leave a comment

The Victoria Day long weekend will end with good weather after an unsettled Sunday and warm conditions are expected to continue into midweek.

Warm temperatures are expected in southern Manitoba
Warm temperatures are expected in southern Manitoba

This Week

Today will be a nice day in southern Manitoba. Skies are expected to be mainly sunny with temperatures climbing into the mid twenties. There will be a slight risk of thunderstorms in the morning in the Red River Valley and south-eastern Manitoba as some instability remains ahead of a weak cold front. The risk of storms should end by the afternoon as westerly winds remove the moist air mass from the region.

Tuesday will be another pleasant day, with temperatures in the mid to upper twenties and mainly sunny skies. A southerly flow will be in place over southern Manitoba, with wind speeds around 20 km/h.

Wednesday will be an unsettled day in southern Manitoba. A south-easterly flow will bring a moist air mass back to the region, causing the atmosphere to become unstable. There will be a risk of thunderstorms in most of southern Manitoba, but at this time it remains unclear how strong storms will become. Models currently show marginal conditions for severe thunderstorms, although it is too early to say what type of risk we’ll end up seeing.

Long Range

Long range models continue to show generally above-seasonal temperatures for southern Manitoba over the next couple weeks. We should see these warm-hot conditions last into early June, if not longer than that. We are only a month away from the beginning of summer, so it is become less likely we’ll see any prolonged periods of cold weather.

Holiday Weekend Turns Unsettled

Brad Leave a comment

Summer warmth will continue in Winnipeg for the weekend as southerly winds continue to pull moisture northwards from the United States. By the latter half of the weekend, conditions will become noticeably more humid as a low pressure system begins moving into the region, bringing with it the first organized thunderstorm threat of 2016.

Today will be a beautiful day for Winnipeg & the Red River Valley with mainly sunny skies over the region as temperatures climb to a high near 26°C. Winds will be out of the south at around 20 km/h. There could be an isolated pop-up shower this afternoon through the RRV, but the chance for that will be quite small and not nearly as much shower activity is expected as was seen yesterday through the Red River Valley. Temperatures will fall to a low near 14°C tonight under clear skies.

RDPS Forecast Surface Temperature valid 00Z Sunday May 22, 2016
It will be another warm day on Saturday with high temperatures in the upper-20’s over Southern Manitoba.

Saturday will be another beautiful day with a high temperature once again near 26 or 27°C under sunny skies. It will be a little breezier than Friday with winds strengthening to around 30 km/h. Expect a low near 16°C on Saturday night with winds out of the south near 20 km/h.

Things will begin to change on Sunday as a low pressure system approaches from the west and some of the more humid air from the US begins working into Manitoba. The day will start off sunny with winds out of the south strengthening to 30-40 km/h. It will begin to feel more humid as the day progresses as dewpoint temperatures climb into the mid-teens. It will be warm, too, with a daytime high near 28°C.

NAM SBCAPE, SFC/850/500 X-Over valid 00Z Monday May 23, 2016
Forecast instability (SBCAPE) and wind crossover on Sunday evening.

Through the afternoon, the threat for thunderstorms will develop across southwestern Manitoba and spread eastwards into the Red River Valley for the evening. Instability will peak over SW Manitoba in the afternoon with SBCAPE1 values approaching 2500 J/kg and then tapering off to the 1500-2000 J/kg range as the axis of instability moves into the Red River Valley. Fairly unidirectional wind profiles combined with 30-40 kt of surface to 500mb bulk shear will favour the development of a line of thunderstorms moving northeastwards. The thunderstorms will likely be moderate-to-strong but at this point the threat for severe thunderstorms seems relatively low in the Red River Valley. West of the Red River Valley there is a slight chance for severe thunderstorms, particularly early on in the event before the thunderstorms develop into a line. The primary threat over southwestern Manitoba with any severe thunderstorms that may form will be large hail. We'll continue to keep an eye on things as they develop and refine the storm forecast if needed.

Unsettled Start to Next Week

Holiday Monday will be lead off an unsettled start to next week. Daytime highs will fall back to the low 20's with showers or thundershowers likely to start off Monday and then general unsettledness continuing through the first few days of next week. Conditions will improve through the second half of the week with warmer temperatures returning to the region.

Winnipeg’s seasonal daytime high is currently 21°C while the seasonal overnight low is 6°C.

  1. Surface-based convective available potential energy ↩