More Wet Weather Through Second Half of the Week

Brad 1 Comment

More wet weather is on the way to Winnipeg & the Red River Valley as a slow-moving upper-level disturbance bears down on Southern Manitoba. The bulk of the rainfall associated with this next system will be quite a bit more concentrated than last week’s Colorado Low with much of the precipitation being produced by a single, relatively narrow band of moderate rainfall sliding across the region.

Winnipeg will see a high of around 12°C today with cloudy skies through the day. Shower activity will push northwards through the Red River Valley over the morning hours bringing a decent chance of some rain to Winnipeg by mid-to-late afternoon. Winds will be breezy out of the southeast at around 30km/h with a bit of gustiness on top.

Clouds will stick around tonight as the temperature drops to around 7°C with a continued slight chance of showers through much of the overnight period. The next disturbance will move into Southern Manitoba late overnight, spreading rain from SW to NE starting near the Pilot Mound/SW RRV region and lifting towards Winnipeg.

NAM 12hr. QPF valid 00Z Friday May 15, 2015
The NAM is forecasting around 10-15mm of rain for much of the Red River Valley on Thursday, with some areas seeing as much as 20-25mm.

Thursday will start off as a fairly rainy morning, then see rain taper off from west to east through the afternoon. Skies will remain cloudy through the day with winds out of the east. Expect a high near 13°C. The low on Thursday night will be around 7°C under mainly cloudy skies.

When all is said and done, it’s possible we’ll see somewhere from 10–20mm of fresh rain, however this entire system may end up shifting slightly further west which would leave the Red River Valley fairly dry until remnant showers pass through on Thursday night. We’ll be sure to keep tabs on things as they develop through the day and update with the most likely outcome later tonight.

Friday will bring a break from the gloomy weather as things clear out through the morning, leaving us with sunshine and a high near 19°C and light winds.

Long Range

This weekend will bring another disturbance through the region that has the potential to produce a significant amount of rainfall – 25–50mm – however there’s still a lot of uncertainty associated with the system and many divergent model solutions at the moment. It will likely be a generally unsettled week at best, and potentially a downright rainy one at worst. Some forecasts are showing some fairly favourable convective parameters on Saturday that would hint towards the first significant thunderstorm day of the year, but a decent capping inversion looks to keep things at bay as long as the current forecasts hold out.

Seasonal Weather Returns

Scott Leave a comment

We’ll see seasonal weather return this week after a chilly weekend. Temperatures will climb into the mid to upper teens by midweek.

Monday will remain cool as we stay in a northerly flow behind a departing low pressure system
Monday will remain cool as we stay in a northerly flow behind a departing low pressure system

Monday

Today will remain below-seasonal, but temperatures will warm somewhat over the weekend’s values. High temperatures should climb into the mid teens in the Winnipeg and Brandon areas. However, areas closer to the US border will remain under thicker cloud cover and will struggle to reach double-digits. The wind will be brisk at 30 km/h from the north.

Tuesday

Tuesday will be a nice day, as temperatures climb into the mid/upper teens under mainly sunny skies. Winds will be light as high pressure settles in over the region.

Wednesday

Wednesday will be similar to Tuesday, but there will likely be a bit more cloud cover as a system passes to our south. Temperatures will be in the upper teens under a mix of sun and cloud and light winds.

Long Range

It appears that temperatures will continue to warm through the end of the week. However, long range models hint at another weather system passing to our south next weekend, which may once again draw down some cooler air from the north. In general, models suggest that our weather will hover near normal values for the next couple weeks.

Multi-Day Severe Weather Setup Leads to Tornadoes, Flash Flooding in Oklahoma

Matthieu Leave a comment

Early May is typically when the severe weather season really ramps up in the US Plains and this week has certainly lived up to that. The region has seen severe weather every day since Wednesday and is expected to see more today. A western troughing pattern has been dominant the past few days, allowing a strong southerly flow to take place in the lower levels of the atmosphere – advecting in plenty of moisture from the Gulf of Mexico located nearby. High levels of instability, coupled with enough shear to support supercells was in place.

[map autofit=”1″ disable_scrollwheel=”1″] [pin tooltip=”Bridge Creek”]Bridge Creek, ok[/pin] [pin]Norman[/pin] [/map]

The worst day of the outbreak tornado-wise occurred on Wednesday where 48 tornadoes touched down from Nebraska, all the way down to Texas. A particularly dangerous situation unfolded in Oklahoma as a supercell with a history of producing tornadoes moved northeast along I-44 and through the large city of Norman where it dropped a tornado, later rated EF-1. The same supercell also produced an EF-2 tornado near Bridge Creek, shortly before it dropped the Norman tornado. Tornadoes were not the only threat on Wednesday; significant rains fell across Oklahoma, including Oklahoma City, which saw trailing supercells hit the city and as a result severe flash flooding. One person died from the storms, while a few dozen were injured. Ditches became raging creeks that spilled their banks onto highways and residential areas. It’s not uncommon to see supercells drop 100mm of rain or more in an hour. Radar indicated that some areas just southwest of Oklahoma City saw over 250mm on Wednesday. Numerous stations in the area broke their daily rainfall records from this event. A state of emergency was issued in 12 counties as a result of the storms.

Chickasha Supercell
The tornadic supercell that hit Norman in its early stages, showing an obvious hook. (Source: Radarscope)
Oklahoma Flooding Rains
Storm total accumulation for Wednesday through 9pm shows areas of over 250mm (pink areas). (Source: Radarscope)

More severe weather is expected today as the trough shifts slightly eastwards. There’s a chance that today could be the second significant tornado day in less than a week in the Plains – Kansas, southeast Colorado and northern Oklahoma regions are under the gun. However, there are still a few uncertainties due to the models showing some mid-day convection possibly limiting the heating. The Storm Prediction Center had issued a moderate risk for the region as of Friday night. Regardless of what happens in the first half of the day, there will be severe storms; residents in the region will have to keep an eye on the sky for large hail, severe winds, torrential rains and even tornadoes!

Cool Weekend Ahead

Brad Leave a comment

Temperatures will remain well below normal through the coming weekend as unseasonably cool air becomes entrenched over the region behind the Colorado Low that brought rain to Southern Manitoba on Wednesday & Thursday.

Today will be a comparatively chilly day with temperatures struggling to climb to a high of just 7°C; this is around 10°C below the average high of 18°C for this time of year. The cool temperatures will be accompanied by gusty northwesterly winds of 30km/h with gusts to about 50km/h throughout most of the day. Skies will be fairly cloudy, but a few sunny breaks will manage to materialize through the day.

Tonight in the Red River Valley will bring cloudy periods and a low temperature dipping just below freezing to –1°C.

Saturday and Sunday will be fairly similar days with highs near 11 or 12°C and mixed skies as some cloud cover streams across the region from North Dakota. Winds will be relatively light out of the north at around 20km/h. Both Saturday and Sunday night will bring some cloud with lows in the 1–3°C range.

Cool Weather Persists Into Next Week

There’s nothing but bad news for those hoping for a quick rebound back to summer-like weather: it’s going to take quite a while for seasonal temperatures to return to the Red River Valley.

The GDPS clearly shows a trough of cold air remaining entrenched over Manitoba.
This image valid Monday morning from the GDPS shows a trough of cold air remaining entrenched over Manitoba. Image depicts 700mb temperatures.

Cooler-than-seasonal temperatures are expected to persist until the middle of next week thanks to the cold trough pictured above remaining stubbornly entrenched over the province. Long-range models are showing a return to seasonal warmth in the high teens for the second half of next week as an upper-level ride begins to build into the region, shunting the colder weather off to the east.