Tag: Rain

Another Storm on the Way

Brad Leave a comment

Wednesday will be a brief reprieve from the showery weather before a fairly potent low pressure system spreads more rain & thunderstorm activity across Southern Manitoba tonight into tomorrow morning and brings dreary weather for Thursday with strong northwesterly winds.

Wednesday
23°C / 13°C
A few sunny breaks; rain overnight.

Thursday
19°C / 6°C
Rain and drizzle tapering off mid-day. Risk of a thunderstorm. Windy.

Friday
19°C / 5°C
Mainly sunny.

Today will be a fairly pleasant day with mostly cloudy skies and a high near 23°C or so. There’s a slight chance of an isolated shower or three through the Red River Valley, including Winnipeg, but for now it looks like the activity should mainly remain to our west over southern Saskatchewan and southwest Manitoba.

Tonight, an inverted trough extending NW from a low pressure system moving through the Dakotas will spread rain with the risk of thunderstorms eastwards into the Red River Valley. Rain will likely start sometime after 1AM and persist until mid-morning Thursday. The temperature will dip to around 13°C.

The Canadian RDPS is one of the models rather bullish on higher precipitation amounts Wednesday night.
The Canadian RDPS is one of the models rather bullish on higher precipitation amounts Wednesday night.

Rainfall totals for tonight are still uncertain; the general agreement is for between 10–20mm, however if substantial elevated convection develops as much as local amounts of 40–50mm may be possible. The low end of precipitation forecasts produce only around 5mm of rain.

I feel fairly comfortable with 10–20mm of rain tonight, but we’ll reassess the elevated convection potential later today and update if necessary. We’ll try and have an update fairly early this afternoon.

Unpleasant Thursday

Thursday will be quite an unpleasant day as Winnipeg moves onto the back side of the low pressure system lifting northeastwards into Ontario. The bulk of the rain should taper off mid-day, but brisk northwesterly winds building to 30–40km/h will accompany cloudy skies and a high struggling to climb into the upper teens. It’s also fairly likely drizzle will persist after the main area of rain moves out, making for a generally dreary day.

Skies will clear out for the evening, although there may be some cloudy periods through the first half of the night with some cloud moving off of Lake Manitoba, and temperatures will drop to a chilly 5 or 6°C.

Fall-Like Friday

Friday will be fairly pleasant, albeit cool, with mainly sunny skies and a high near 19 or 20°C. Winds will be fairly light through the day.

Friday night should bring clear skies and a low near 5 or 6°C.

A Look Ahead to the Weekend

The upcoming weekend is looking fairly good with unpleasant weather staying to our north. It’s looking like plenty of sun is in store with daytime highs in the ballpark of the seasonal 21°C mark and overnight lows moderating by the end of the weekend.

Major Low Brings Cooler and Unsettled Weather

Brad Leave a comment

A major low pressure system developing in the United States and forecast to lift northwards into the Eastern Prairies through the weekend will bring generally unsettled weather ahead of a more cohesive area of precipitation that will move through on Saturday night.

Friday
22°C / 15°C
Mostly cloudy with a chance of scattered showers

Saturday
19°C / 15°C
Mostly cloudy

Sunday
23°C / 15°C
Rain ending in the morning; sunny breaks with a risk of strong-to-severe thunderstorms thereafter

Perhaps the single most important thing to keep in mind with today’s forecast is the fact that weather models have little consensus on what’s going to happen over the next few days other than the fact that there will be a large low pressure system that will impact an area somewhere between the Rocky Mountains and the Great Lakes.

That being said, it looks like the next several days will bring mixed weather to Winnipeg. Today will see a chance for scattered shower activity as a weak shortwave rolls across the Red River Valley, but nothing nearly as bad as what hit the city last night, where up to 80mm of rain fell in a rapid deluge through portions of the city that resulted in wide-spread flooding through the hardest hit areas.

Temperatures will climb to around 21 or 22°C this afternoon with a light wind out of the north. Tonight will be mainly cloudy with fairly light winds and a low near 15°C.

Saturday: The Low Approaches

Tomorrow will see mainly cloudy skies with a high of just 19 or 20°C. Winds will pick up out of the northeast to 30-40km/h as the main low pressure system for the weekend strengthens and lifts northwards through the Dakotas. By supper time, rain with the chance for embedded thunderstorms will spread through North Dakota into Southern Manitoba, reaching Winnipeg later in the evening.

The RDPS is forecasting an intense convective complex with substantial rainfall amounts on Saturday night. Who knows if it's correct.
The RDPS is forecasting an intense convective complex with substantial rainfall amounts on Saturday night. Who knows if it’s correct.

The rest of Saturday night will be quite rainy with 10-20mm of rain likely across most of Southern Manitoba with localized amounts in excess of 30-40mm due to embedded convection in the precipitation shield. Some models, such as the RDPS pictured above, want to produce upwards of 50-75mm of rain, although at this point that’s likely overdone and a symptom of what’s known as “convective feedback” in the model, something that ends up causing the model to produce too much precipitation when there is widespread convection occurring. Temperatures will drop to around 15°C again with winds out of the northeast at around 30km/h.

More Unsettled Weather on Sunday

The weather on Sunday will likely improve as the low pressure system lifts through the Red River Valley and pushes off to our northeast. Rain will taper off in the morning and Winnipeg will be left under mostly cloudy skies in what’s known as the “dry slot” — the area behind the cold front located between the frontal precipitation and wrap-around precipitation denoted by descending dry air aloft. The high will climb to around 22°C with some strong northeasterly winds becoming light in the afternoon.

Significant instability associated with the low pressure system will be in place, and even with temperatures climbing only into the low 20’s, it will be enough when coupled with the significant moisture in place to present a risk for strong-to-severe thunderstorms. We’ll have more information in the comments on Sunday.

Things will begin to clear out on Sunday night as the temperature drops to around 13°C.

Into next week looks fairly benign with temperatures gradually returning towards normal by week’s end. There will be a couple cool nights in the coming week with overnight lows dipping into the single-digits.

We’ll be keeping an eye on this system as it develops; slight alterations in the track of the system could dramatically impact forecasts, so if any changes are needed we’ll note them below in the comments. All in all it will be a mediocre weekend followed by an improving week.

More Unsettled Weather

Brad Leave a comment

Although nothing as notable as this past weekend’s rain event is in store, unsettled weather returns for the second half of the week.

Another sizeable low pressure system is making it’s wet presence felt, but this time the hardest hit area will be Southern Alberta where some portions in the foothills may receive as much as 200mm of rain this week. This system will slowly lumber eastwards through the next few days, slowly weakening as it does so but still producing thunderstorms and showers as it goes.

Wednesday: Severe Thunderstorm Risk for Extreme SW Manitoba

Wednesday
25°C / 13°C
More cloud than sun. Warm & breezy.

Winnipeg will see fairly pleasant weather today with mixed skies, likely leaning towards more cloud than sun, and a high near 25°C with a fairly stiff easterly wind at 30-40km/h thanks to a surface trough building southeastwards through North Dakota.

The main upper low, the heart of this large disturbance, will gradually edge eastwards through the day and will trigger thunderstorms, with some severe storms possible, through portions of southern Saskatchewan and southwestern Manitoba. Shower activity will start off the day in much of Southern Saskatchewan, but the southeast portion of the province will likely see things destabilize enough through the day that thunderstorms are likely by mid-to-late afternoon. The storm activity is most likely to initiate through western North Dakota and then build north/northwestward along the surface trough into SE Saskatchewan and into extreme SW Manitoba through the early evening.

There is an organized threat of severe weather with these storms; we’ve gone with a slight risk due to almost every severe weather parameter looking fairly good except lacking in some subtle way. The main threats will be strong winds and large hail, especially out of any storms that develop early and are sustained as discrete supercells. If the storms develop into a cohesive line, the severe threat will be diminished, although non-zero. There will be a very slight chance for tornadoes thanks to excellent low-level shear, low cloud bases, and a vorticity rich environment being advected eastwards by the upper-level low.

Today will bring a slight risk of severe thunderstorms into SE Saskatchewan and SW Manitoba.
Today will bring a slight risk of severe thunderstorms into SE Saskatchewan and SW Manitoba.

The severe storm threat will push eastwards into the Virden & Melita regions of Manitoba in the early evening with the main threats being strong winds and large hail. It does look like the tornado threat should be restricted to the Saskatchewan side of the border. Southwest Manitoba is in for quite a soaking overnight as the storms expand into an area of convectively driven rain; around 15-20mm is likely for most areas south of the Trans-Canada Highway and west of the Red River Valley (RRV), with as much as 40-50mm possible in areas that see thunderstorm activity as well.

As the area of showers pushes eastwards, it will gradually weaken into an area of showers with possible embedded thundershowers. It looks to reach Winnipeg by Thursday morning.

Thursday: Back to Wet Weather

Thursday
23°C / 14°C
Periods of rain. Around 10mm.

Thursday will be a cloudy day with a high near 23°C. Shower activity will be in the region in the morning and lift off to the northwest, however while that happens a new batch of rain will be develop to our south and lift northwards through the RRV. Around 10mm seems most likely through the day across most of the region, although if heavier shower activity ends up developing we may see closer to 15mm here in Winnipeg.

The shower activity will taper off on Thursday evening as it all lifts northwestwards into the Interlake and Parkland regions of the province. Winnipeg will see some clear breaks and a low near 14°C.

Friday: Cold Low Showers

Friday
23°C / 14°C
Mixed skies; showers or thundershowers developing midday.

Friday will see us underneath the upper-level low which essentially means that there will be a bunch of cold air high up in the atmosphere. With mixed skies, we’ll see temperatures increase towards our high of 23°C fairly quickly through the morning. By mid-day, we’ll likely have hit our high temperature and the atmosphere will become quite unstable. Expect widespread shower and thundershower activity through the Red River Vally. Rainfall amounts will be highly variable and dependant on how many showers any one spot sees and how fast things move along.

Overnight, the shower activity will consolidate to right around the upper low on Friday night as it drifts through our region and into Minnesota. The temperature in Winnipeg will drop to around 14°C.

Unsettled Weekend Ahead; Soggy Sunday?

Brad Leave a comment

Southern Manitoba will be under the influence of a complex low pressure system this weekend that will spread multiple bands of precipitation across the province. Things are a little uncertain for Sunday – Father’s Day and the Manitoba Marathon – but it’s looking probable that it may be quite wet.

Friday
21°C / 12°C
Increasing cloud; chance of afternoon showers. 5-10mm of rain overnight.

Saturday
18°C / 14°C
Cloudy; some light rain or drizzle possible.

Sunday
18°C / 10°C
Rain likely; up to 20mm.

Today will be a relatively nice day. Cloud coverage will gradually increase and there will be a slight chance of showers in the Red River Valley this afternoon as rain spreads eastwards across southern Manitoba. The temperature will climb to around 21°C.

Showers will move into the Red River Valley through the evening with around 5-10mm falling. While there may be an odd rumble of thunder, overall the thunderstorm threat is low to non-existent. Rain will move from southwest to northeast and lift into the Interlake region, leaving us with overcast skies by morning. The low temperature will sit near 12°C.

Total expected rainfall for the first wave of rain today through tonight into Saturday morning.
Total expected rainfall for the first wave of rain today through tonight into Saturday morning.

Saturday will be a mainly cloudy day with some showers or drizzle likely. It doesn’t look too wet, but overall it will be sort of a dreary day with sporadic precipitation. Further north, through the Parkland region eastward into the Interlake, there will likely be rain for much of the day. The high temperature will be near 18°C and expect the temperature to drop to around 14°C on Saturday night.

Uncertain Sunday

Sunday, which marks Father’s Day and the ever-popular Manitoba Marathon, has a little more uncertainty associated with it. The general weather picture shows a stalled out low pressure system over SE Saskatchewan and SW Manitoba while a Colorado low lifts northwards through the Dakotas. The evolution of the feature is very complicated, and small changes in the upper-level flow could mean big changes to the expected weather over Southern Manitoba. I’ll give the most likely solution right now, and leave updates in the comments below if it looks like an alternate solution becomes more plausible.

The GDPS is forecasting a very wet Sunday with 10-20mm of rain through many areas of Southern Manitoba.
The GDPS is forecasting a very wet Sunday with 10-20mm of rain through many areas of Southern Manitoba.

Sunday morning will provide a cloudy start to the marathon with some scattered showers or drizzle about. The temperature should be around 15°C. By mid-day, more concentrated shower activity will push northwards through the Red River Valley, with an area of rain covering much of southern Manitoba (save for locations near the Saskatchewan border) by early-to-mid afternoon.

The rain will persist into the evening and taper off by Monday morning. Total rainfall amounts are quite variable, but overall it seems like 10-25mm is possible in most regions, with higher amounts near the US border through SE Manitoba and along the western escarpment of the Red River Vally northwards into the Riding Mountains. Anywhere from 25-40mm seems possible in these areas.

The temperature will drop to around 10°C on Sunday night after the rain tapers off.

Unsettled Pattern Continues

Next week is looking fairly unsettled as yet another major disturbance takes up residence on the Prairies. In general, more cloud than sun will be seen through the week. Heavy rainfall will set up in Alberta on Monday, and as the system develops it looks like a large area of convection will develop across the Northern Plains and lift northwards into the southern Prairies, including Winnipeg and the Red River Valley, by mid-week.

It’s a long ways off, though, so we’ll take a closer look later in the weekend when things become a little more clear.