Rain Brushes Southern Manitoba

A powerful low pressure system drenching North Dakota and Minnesota will brush the southeastern portion of the province today. For the rest of us, fairly quiet weather will prevail with slightly below-normal temperatures.

Wednesday
17°C / 8°C
Mainly cloudy. Outside chance of some light showers.

Thursday
18°C / 6°C
Mainly sunny.

Friday
23°C / 13°C
Sunny, then increasing cloud late in the day.

The main weather story today will be the low pressure system working its way through North Dakota and Minnesota. Although this system will spread cloud through the entirety of the Red River Valley, rainfall will be constricted to the southeastern portion of the Red River Valley into SE Manitoba. At this point, it looks like the main area of rain will remain south and east of Steinbach. There’s a slight chance of showers backing into Winnipeg and the SW Red River Valley (Altona, Winkler), but if any precipitation managed to push that far north or west, it would remain very light.

Forecast rainfall amounts for the system clipping southeastern Manitoba through June 11th and 12th.
Forecast rainfall amounts for the system clipping southeastern Manitoba through June 11th and 12th.

Otherwise, it will be a mainly cloudy day with perhaps a few sunny breaks through the first half of the day. Winds will be a little breezy out of the north at 20-30km/h. Temperatures will top out around 17°C. Clouds will begin to push off to the east overnight, however the bulk of the RRV won’t see complete clearing until Thursday morning. Overnight lows will be near 8°C.

Cool But Pleasant End to the Week

Thursday and Friday both look to be quite nice, with temperatures some 5°C below normal returning to seasonal values. Thursday will see clearing skies as temperatures climb to 18°C. Winds will be light out of the north as a ridge of high pressure begins working its way eastwards into Manitoba. There may be a slight chance of some shower or thundershower activity over western Manitoba, but here in the Red River Valley things look sunny and dry. The overnight low on Thursday will generally sit around 6°C; this will likely be the coolest night for the next while.

Friday will be another mainly sunny day with warmer weather returning as the ridge of high pressure shunts off to the east and a southerly flow redevelops over the province. Under mainly sunny skies the temperatures will climb to near 23°C. Cloud will move into the Red River Valley late in the afternoon or the evening and the next system pushes into southwestern Manitoba. Temperatures will drop to around 13°C.

Unsettled Weekend

This weekend will be marked by unsettled weather as a major low pressure complex moves into Southern Manitoba and the Northern Plains of the United States. Rain, with the chance of thundershowers, will push into southwestern Manitoba on Saturday morning. There’s uncertainty as to what will happen after that, but at the time it appears that rain will likely slide eastwards along the international border through the day.

GDPS 24hr. precipitation amounts from Saturday evening to Sunday evening. The GDPS is forecasting 5-10mm of rain in the RRV for this period, with higher amounts west, south and east.
GDPS 24hr. precipitation amounts from Saturday evening to Sunday evening. The GDPS is forecasting 5-10mm of rain in the RRV for this period, with higher amounts west, south and east.

Afterwards, the general trend looks to be a shift northwards with the precipitation towards the northern Red River Valley, and then things push out late in the day on Sunday. Daytime highs on the weekend should rest in the low 20’s while overnight lows hover near the 11-12°C mark.

Fairly Normal Start to the Week

This week will start out with fairly normal conditions for early June with a chance for rain, and moderate temperatures.

Monday will be a nice day in southern Manitoba
Monday will be a nice day in southern Manitoba

Monday

Monday
22°C / 13°C
Mainly sunny

Today may start out with a bit of rain in the morning as a piece of upper-level energy swings through but skies should quickly clear, making for a pleasant day. Any rain that does fall in the morning will be light, so it won’t be a big deal. By the afternoon we should see mainly sunny skies with temperatures in the low twenties and light winds.

Tuesday

Tuesday
23°C / 10°C
Chance of showers or thundershowers

Tuesday will see the chance for showers and thundershowers in the Red River Valley and south-eastern Manitoba ahead of an approaching trough. Any thundershowers that develop will present the risk of small hail and gusty winds. For those areas that miss out on the showers and thundershowers, it will be a nice day with temperatures in the low twenties and a breezy south-west wind.

Wednesday

Wednesday
19°C / 5°C
Mix of sun and cloud

A cold front will blow through southern Manitoba early Wednesday morning, setting us up for a slightly cooler day. Highs on Wednesday will be in the upper teens in most areas (perhaps a few readings in the low twenties), with skies being a mix of sun and cloud by the afternoon. The wind will be breezy and from the north.

Long Range

The long range forecast suggests we’ll continue to see normalish weather for the foreseeable future. That means high temperatures in the low to mid twenties and the frequent chance for rain or thunderstorms (albeit generally of the non-severe variety).

Elsewhere in Weather News: June 7th, 2014

Large Hailstorm causes Millions in Damages

This past week featured severe thunderstorms that tore through the Nebraska countryside producing extremely large hail in the region. Conditions were primed for a severe weather outbreak this past Tuesday; moisture streamed up from the Gulf of Mexico, a strong jet streak was in place overhead and the environment was relatively uncapped. Convective Available Potential Energy (CAPE) was quite high that day which was a significant contributor to the large hail sizes observed. Generally the higher the CAPE, the faster the updraft velocity which means that the updraft can support larger hailstones. Supercell thunderstorms were triggered Tuesday afternoon and persisted through the evening, trailing along the warm front that bisected the region.

In total over 200 hail reports were submitted on Tuesday and of these 38 were considered large hail reports (hail of 5cm in diameter or larger). The most damage caused that day appeared to come out of the town of Blair, Nebraska where hail caused major damage. Windows were blown out and car windshields smashed by the baseball size hail that fell – damage totaled in the hundreds of millions. Other storms along the warm front, the weather feature that triggered the severe weather, moved into the Omaha area not only bringing hail, but also torrential downpours. 13.5mm of rain was recorded in 3 minutes at the Omaha airport!

Hail damage in Hoover, NE shows the strength of baseball size hail, completely shredding the siding and breaking the windows. (Source: Kevin Krohn)
Hail damage in Hoover, NE shows the strength of baseball size hail, completely shredding the siding and breaking the windows. (Source: Kevin Krohn)

There is a possibility for more severe storms this weekend in Texas and New Mexico, but the parameters are not as as favourable for severe weather as seen this past Tuesday in Nebraska. Models show the active pattern continuing in the US Plains into next week, and rightfully so as severe weather season nears its peak.

A Fairly Pleasant Weekend

Although temperatures will be a little below normal for foreseeable future, a fairly pleasant few days are on tap for Winnipeg. A ridge of high pressure over the central Prairies will work at clearing out the clouds giving us plenty of sun for Friday and Saturday while winds slowly diminish. A low passing through on Sunday will mark the return of potentially rainy weather.

Friday
19°C / 7°C
Sunny with afternoon clouds. Breezy.

Saturday
18°C / 7°C
Mainly sunny.

Sunday
18°C / 8°C
Cloudy periods with a chance of showers.

Significantly cooler air than seen over the past week is working its way across the Prairies into Southern Manitoba, dropping daytime highs from the the mid-to-high 20s to the high teens. Temperatures will remain roughly 5°C below normal for the next week as a much cooler pattern locks in; daytime highs aren’t expected to reach over 20°C until late into next week.

Today will bring some late morning/afternoon cloud with a breezy west-to-northwesterly wind at around 20-30km/h. Temperatures will reach around 18°C. Expect clearing skies tonight and a low of around 7°C.

Tomorrow will be very similar to today except with a little less cloud and lighter winds. High near 18°C once again and a low near 7°C again.

Showery Sunday?

A weak low pressure system is forecast across Southern Manitoba on Sunday, bringing a renewed chance of showery weather. At this point, it looks like little in the way of particularly active weather will occur; even a rumble of thunder looks out of the question.

Probability matched mean precipitation from the SREF model for Sunday morning.
Probability matched mean precipitation from the SREF model for Sunday morning.

In general, the system is expected to spread some light shower activity from west to east across Southern Manitoba through the morning hours, persisting into the afternoon. Overall amounts look to be low; in the image above, I’ve used a probability matched mean ensemble[1] which can better capture higher amounts embedded within the mean precipitation field, and it still only shows around 2-4mm for most areas.

There are some hints the system may pick up strength and produce 5-10mm over the woods from Pinawa down to Sprague, but it’s still a little too far out to say much reliably.

Sunday won’t be all showers and cloud, though with a good chance of a few sunny breaks through the day. Highs will be near 18°C once again with an overnight low around 8°C.

Heading into next week it looks as if the cooler temperatures will continue with a couple more chances for precipitation through the first half of the week.


  1. For those who are curious, this takes the ensemble mean value, but matches the rain rate distribution in the ensemble mean field to the complete ensemble. Can help prevent “smearing” of the precipitation field.  ↩