Tag: Humid

Warm Late-Summer Weather Continues

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A persistent southerly flow over southern Manitoba will keep the seasonably warm and humid conditions in place for a for a few more days.

RDPS 2m Temperature Forecast valid 21Z Wednesday September 18, 2024
A stalled low over eastern Montana will continue to pump warmer air northwards into southern Manitoba this week.

A quick note to start: the lack of forecasts last week was due to the fact that I’m dealing with a long-lasting bout of COVID–19 that’s sidelined me for a while now. I’m on a [gradual] up and up now, with symptoms finally receding after testing positive on rapid tests for a whopping 11 days in a row. Not a fun time, looking forward to getting back at life.

Daytime highs in the mid-20s will continue into mid-week for the Winnipeg area as a persistent low pressure complex to the west supports a southerly flow across the region. Daytime highs for Tuesday and Wednesday will likely sit around 25 °C; it could be a touch cooler if a bit of a stronger cold pool is left behind from overnight convection, or a tad warmer if we clear out early and a stronger southerly flow can develop earlier in the day.

The humidity will also be notable for mid-September, with dew point values in the mid- to upper-teens, potentially reaching around 20 °C on Wednesday. This is more humid that the region often sees at this time of year, but the lower daytime highs in the 20s should keep the worst of the heat effects at bay. In the sun, the heat and humidity could combine to feel like it’s in the low 30s rather than mid-20s.

RDPS 2m Dew Point Temperature Forecast valid 21Z Wednesday September 18, 2024
In addition to the seasonably mild temperatures, it will continue to be humid across southern Manitoba.

Overnight lows both tonight and tomorrow night will sit in the mid-teens.

Weather-wise, today should bring clearing skies as the disturbance that brought rain and thunderstorms to the region yesterday pushes off to the east. A few clouds will begin to build back in tonight, leading to mixed skies on Wednesday as a cold front approaches the region from the west.

A few showers are possible on Wednesday; it looks like they should be weak, though the slow-moving nature of the cold front and broad forcing could result in a narrow band of slow-moving showers that could produce some locally higher amounts in the 15 to 25 mm range. I’m doubtful Wednesday will be a “wet” day, more likely a cloudier one with the chance of passing showers.

The cloudiness and chance of showers will continue into Wednesday night.

Unsettled End to the Work Week

The low that’s been sitting to the west all week will finally get moving on Thursday, moving into southwest Manitoba on Thursday and sliding into northern Manitoba on Friday.

This will bring a notable change in the weather to southern Manitoba. To start, both Thursday and Friday could bring wet conditions to the Red River Valley. On Thursday, showers and thunderstorms will begin possible through much of south-central and southeast Manitoba as the forcing along the cold front picks up with the advance of the low. This activity will likely continue into the night as it pushes northeast.

Winds will finally shift on Thursday from the persistent southerly at 20 to 30 gusting 50 km/h seen much of this week to westerly winds of 15 to 30 km/h.

On Friday, showers in the instability on the back-side of this system may clip through southern Manitoba as cooler air moves into the region. Daytime highs will cool into the low 20s by the end of the work week.

Long Range Outlook

Heading into the weekend, more settled conditions will develop over the region as near-seasonal temperatures return. Winnipeg will see partly cloudy conditions over the weekend with daytime highs in the upper teens and overnight lows near the 10 °C mark.

This trend looks to continue into the start of next week.

Today’s seasonal daytime high in Winnipeg is 18 °C while the seasonal overnight low is 6 °C.

Hot & Humid Conditions Ahead With Severe Thunderstorms Possible Sunday

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An energetic and dynamic weather system lifting through the Prairies will bring hot and humid weather to Winnipeg this weekend. As it passes through on Sunday, severe thunderstorms will be possible across the region.

RDPS 2m Temperature Forecast valid 21Z Saturday August 24, 2024
Hot and humid weather will build into the southeastern Prairies this weekend.

Now that the morning fog and stratus has burnt away, it will get cooking over the Red River Valley. Temperatures will climb close to 30 °C with dew points close to 20 °C making it feel like the upper 30s through the afternoon.

Heading into the night, a low pressure centre will develop over southern Alberta and begin moving northeast. As it forms, it will begin to lift a warm front northwards out of the United States. This will bring partly cloudy conditions to the region overnight with strengthening southerly winds. Winds in Winnipeg will likely reach around 20 km/h by early Saturday morning, then quickly strengthen into the 30 to 40 km/h range as it warms up.

Saturday will bring mixed skies to Winnipeg with a high in the low 30s. Dew point values should sit in the high teens, though an axis of ≥ 20 °C dew points is forecast to lie immediately west of the Red River Valley. This again will result in humidex values in the upper 30s through much of Saturday.

It will be a hot, muggy night on Saturday night with overnight lows dipping only into the low 20s. The breezy southerly winds should continue through the night under partly cloudy skies.

Severe Thunderstorm Threat Develops on Sunday

The system moving through the Prairies, in addition to the heat and humidity here, will bring multiple rounds of potentially severe thunderstorms to the broader region. Severe thunderstorms are possible this afternoon over southwestern Saskatchewan; these storms will blossom into an area of showers and thunderstorms that track northeast across southern Saskatchewan overnight. On Saturday, another round of severe thunderstorms are possible beginning near the Manitoba/Saskatchewan border in the afternoon and spreading northeast across the Interlake through the night. Much of this activity is expected to stay north of the Trans-Canada Highway corridor in the Red River Valley, but isolated thunderstorms look possible in SW Manitoba.

By Sunday, though, it becomes the Red River Valley’s turn for thunderstorm activity. Sunday will likely be the warmest, muggiest day of the three with highs in the low 30s and dew points climbing into the low 20s, making it feel a lot closer to 40. The southerly winds will weaken in the afternoon as a warm-sector trough moves into the region.

For the enthusiasts out there: both the dynamic and thermodynamic setup for Sunday points towards a potent thunderstorm risk. The heat and humidity will drive MLCAPE values to over 2,500 J/kg, while late the day the right entrance to a 50 knot jet streak at H500 slides over the region. Surface winds ahead of the warm-sector trough are solid at 15 knots out of the SSE, but winds become weak and disorganized between the trough and the cold front. Bulk shear values are roughly 30 to 35 knots. MLLCL values are forecast to be moderate, roughly around 3,000 feet. Lastly, PWAT values will climb above 45 mm with Bunker storm motion values around 15 to 20 knots out of southwest.

NAM MLCAPE Forecast valid 21Z Sunday August 25, 2024
An axis of significant amounts of instability, capable of producing dangerous thunderstorms, will develop over the Red River Valley on Sunday.

The result of all that is that there is a potent thunderstorm risk that will develop on Sunday afternoon. Either the warm-sector trough or approaching cold front could be drivers for initiation, and both will be capable of producing dangerous thunderstorms capable of producing all modes of severe weather: very large and damaging hail, wind gusts of 90 to 120 km/h or higher, tornadoes, and torrential downpours capable of localized flash flooding.

All storms will have a roughly equal chance of producing damaging hail or wind gusts. There is a non-zero tornado threat across the region, though it will likely be maximized south of Winnipeg; a weak low centre is forecast to develop over northwestern North Dakota and weaken as it tracks northeast; if it holds together it could result in a stronger, more backed surface flow towards the southwestern Red River Valley that could enhance the tornado risk. Every thunderstorm will produce very heavy rainfall, but relatively high storm motions will likely limit the amount of rain a single storm gives to any one place. Widespread amounts of 20 to 50 mm are possible with the thunderstorm activity. If an area happens to have multiple thunderstorms pass over them, or a storm lingers for a longer period, then accumulations of 50 to 125 mm will be possible.

The thunderstorm activity will track east into the evening, pushed along by an advancing cold front moving through the region. Temperatures will head back down into the upper teens with a moderate northwest wind overnight.

Long Range Outlook

Next week will be an unsettled one for the region with seasonal temperatures. Monday should be pleasant, then cloud and showers will be possible on Tuesday as the region is clipped by a system moving through the Dakotas.

Showers and thunderstorms will again be possible on Wednesday evening through Thursday as another low pushes into the Prairies.

And that’s it for today! Stay safe in the heat, enjoy what you can, and make sure to check on anyone you know who’s more vulnerable (especially on Saturday night).

Be sure to stay tuned for any alerts issued by the MSC in the days to come.

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

Warm, Humid, and Unsettled Weekend Ahead

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Southern Manitoba will see humid conditions develop this weekend as a warm and unsettled pattern develops over the region.

RDPS 2m Dew Point Temperature Forecast valid 21Z Saturday June 15, 2024
Humid conditions will develop across southern Manitoba on Saturday.

To end the work week, an area of high pressure will gradually shift east out of the province through the day. This will bring a warm and settled day to the region with a high in the 25 to 30 °C range and partly cloudy skies. Southerly winds will begin to pick up later in the day and mark the beginning of the weather pattern that will persist through the weekend.

An upper trough will dig southwards over western North America through the weekend; this will support a prolonged southerly flow at the surface while disturbances eject northeast across the region over the next few days.

Humid Weather Arrives This Weekend

The southerly winds at the surface will draw heat and humidity northwards through the weekend. Daytime highs won’t be excessive through the weekend, likely in the mid-20s, but the region will likely see its first surge of humid conditions.

The humidity will be comfortable today with dew points in the low teens, but more humid conditions will quickly develop on Saturday. Dew point values will climb into the mid- to upper teens on Saturday, then hover in the 16 to 20 °C range overnight Saturday, then increase towards 20 °C ahead of a cold front on Sunday. As the cold front sweeps through on Sunday afternoon, drier air will sweep into the region and bring relief.

The humidity will keep temperatures warm on Saturday night with overnight lows in the 18 to 22 °C range across many parts of southern Manitoba.

Stormy Conditions Possible

Weather-wise, there will be several chances for stormy weather through the weekend. The first disturbance will be a weak area of low pressure that pushes into southern Manitoba tonight. Scattered showers and thunderstorms will be possible through the second half of the night into Saturday morning.

The activity will taper off on Saturday afternoon, then another disturbance will bring another chance of showers and thunderstorms to the region on Saturday evening and overnight. Sunday will be more settled, but there will be a low chance of showers or thunderstorms with the cold front as it sweeps east.

Long Range Outlook

Next week will start unsettled as the deep upper trough remains over western North America. Waves of rain and thunderstorms will be possible across southern Manitoba on Monday and Tuesday, then more settled conditions will move in for the middle of the week.

Today’s seasonal daytime high in Winnipeg is 23 °C while the seasonal overnight low is 11 °C.

Heat Builds in for the Weekend

Brad Leave a comment

An upper ridge building into the eastern Prairies will bring hot conditions to southern Manitoba this weekend.

RDPS 2m Temperature Forecast valid 21Z Sunday July 2, 2023RDPS 2m Dew Point Temperature Forecast valid 21Z Sunday July 2, 2023
Sunday will bring the warmest weather of the next few days as hot temperatures and high humidity build into the region.

Seasonably warm conditions will build into southern Manitoba over the next few days with daytime highs climbing towards the 30 °C mark. In Winnipeg, today will bring mainly sunny skies that give way to some cloud in the afternoon while a ridge of high pressure brings sunny skies for Saturday.

Temperatures both days will climb into the upper 20s. Humidity levels will be comfortable in the mid- teens both days. For those heading out to enjoy Canada Day ???????? on Saturday, it will be a beautiful day to spend time outdoors!

On Sunday, the heat will really arrive as temperatures climb into the low 30s with increasing humidity. By the late afternoon, dew point values could reach as high as 20 °C, which would make it feel more like the upper 30s.

On Sunday afternoon, a warm-sector trough — typically an area of lower pressure near the middle of a large area of warmer air — will begin pushing across southern Manitoba. This feature will be an area of concern for severe thunderstorm development later on Sunday.

The thunderstorm potential will be significant on Sunday thanks to ample heat and humidity at the surface and relatively cool temperatures aloft. MLCAPE values could exceed 2,000 J/kg in an environment with 20 to 30 knots of 0–6 km bulk shear. Veering wind profiles would support supercell structures, but moderate westerly forcing along the line would likely support upscale growth into the evening hours. Capping will be marginal — 700 mb temperatures are forecast to be around 9 °C — so there is uncertainty with where the southern end of the line would develop. Wind profiles aren’t overly backed at the surface, so this setup wouldn’t likely produce a widespread tornado threat. If a thunderstorm was able to tap into all the available energy, though, an isolated tornado threat could develop. More likely, these thunderstorms would be capable of severe hail and torrential rainfall.

The details of this could change between now and Sunday, but at this point it looks like Sunday will be the hottest day of the next few and bring an organized severe weather risk to the region for late in the day.

Long Range Outlook

A weak cold front will push through Sunday night easing the humidity across the region.

Through the start of next week, temperatures should sit closer to seasonal values with variable cloudiness as cooler air moves in under a slow-moving upper trough that moves into the region. Some showers could be possible, but right now it looks like the start of the week will be mostly dry for Winnipeg.

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