Elsewhere in Weather News: July 13th, 2013

Matthieu Leave a comment

Strong Typhoon Makes Landfall in Taiwan

A strong typhoon, Typhoon Soulik, has made landfall in northern Taiwan last night bringing heavy rainfall and strong winds in the order of around 160km/h – considered category two. Soulik, once a category four typhoon, encountered cooler waters before making landfall and Taiwan’s rugged terrain continues to tear it apart. It’s expected to cross the South China Sea and make a second landfall on China’s southeast coast as a tropical storm. Most models show it heading into China’s mainland weakening into a tropical depression and further on, a low pressure system. Although only a tropical depression, Soulik will bring copious amounts of rain into the mainland, prompting fears of possible flooding later this weekend.

Soulik

IR image of Soulik on Friday night. Expected track and intensity overlayed. (Source: CIMSS)

As of Friday night, electricity disruptions, 1 death and two dozen injuries had been reported. Around 8,500 people had been evacuated prior to Soulik making landfall because they lived in landslide-prone terrain.

Active Pattern Developing

Brad Leave a comment

A more active pattern will be setting up over Southern Manitoba as a southwesterly flow aloft develops thanks to a quasi-stationary high pressure system that will set up shop over eastern North America. This will bring us multiple chances of rain and thunderstorms over the next 5 days or so.

Friday

28°C / 16°C
Showers or thunderstorms ending in the morning, then a mix of sun and clouds with the slight chance of a thunderstorm.
Saturday


30°C / 16°C
More sun than cloud. Increasing cloud then risk of showers or thunderstorms overnight.

Sunday

28°C / 16°C
Mainly sunny. Might actually not rain.

Friday

We’ll see a rainy start to the day as the remnants of Thursday night’s nocturnal convection begin to dissipate over the Red River Valley. Showers or thunderstorms will taper off through the morning, leaving us with a mix of sun and cloud by midday. Thunderstorms will redevelop along the main surface trough in Southern Manitoba in the afternoon but the complicating factor will be the positioning of the trough, which is extremely uncertain at this point.

Forecast location of the surface trough at 1PM CST from the RDPS.

Forecast location of the surface trough at 1PM CST from the RDPS.

It seems most likely that the trough will be east of Winnipeg by the time things redevelop along it, although due to that uncertainty we’re keeping a slight chance of another thunderstorm through the early afternoon in for Winnipeg. We’ll update in the comments below if it’s readily apparent that the trough will be east of town by mid-morning. We’ll see clearing skies tonight as we head to a low of around 16°C.

The Weekend

Saturday will be a hot day with relatively comfortable humidity. We’ll see temperatures climb to around the 30°C mark again across the Red River Valley under a mix of sun and cloud – although there should be more sun out there than cloud. We’ll see some increasing cloudiness in the evening as a weak upper trough pushes into the province. There will be a chance of showers or thunderstorms through the overnight period for a large swath of Southern Manitoba, although at this point the best chance looks to be from Dauphin to Brandon and then in the Red River Valley near the western escarpment.

Sunday will be a nice day where we might actually have no chance of rain! Temperatures will climb back into the high 20’s – probably close to 28°C again – under mainly sunny skies. Sunday night will be clear with a low near 16°C.

Next Week

At this point, Monday and Tuesday both look like relatively rainy, possibly stormy, days as a train of disturbances move over Southern Manitoba. There are hints that once we get past the first couple days, we’ll return to a more stable pattern, but first thing’s first; we’ll continue to have updated thoughts and details in the comments below!

Hot Weather Building In; Severe Storms to End Week?

Brad Leave a comment

Hot, increasingly humid weather will begin working it’s way back into Southern Manitoba as a southerly flow at the surface, advecting moisture northwards from the US Plains, combines with an upper ridge over the Prairies that will work to crank up the heat.

Model winds at 500mb showing the strong upper-level ridge forecast over the Prairies on Thursday.

Model winds at 500mb showing the strong upper-level ridge forecast over the Prairies on Thursday.

Today

Wednesday

28°C / 15°C
Sunny.

We’ll see a pleasant day today with sunshine dominating the skies and a light northwesterly wind. Temperatures should climb up to around 27°C while the northerly winds keep the humidity down making it a very comfortable summer day. Skies will remain clear overnight as we drop to a low of around 15°C. There will be a very slight chance of a thundershower or two in the Red River Valley through the afternoon hours, but if they do develop they’ll most likely be tied to areas along the western escarpment and northwards towards Riding Mountain park. There would be a very marginal chance of any of these storms becoming severe; if any were to the main threats would be heavy rain and large hail.

Thursday & Friday

Thursday

30°C / 19°C
Sunny & increasingly humid.

The heat will build a little more on Thursday, but the real big difference will be the humidity which will become very noticeable as the winds shift around to the south on Wednesday night and allow the dew point to start climbing. They should reach the mid-to-high teens by Thursday evening which, when combined with our expected daytime high of 30°C will make it feel more like the mid-to-high 30’s. No storms are expected as a strong cap keeps everything in line.

Friday

28°C / 14°C
A mix of sun and cloud; showers or thunderstorms with passage of cold front. Very humid until front passes.

Friday will be the most active day of the week as ample heat and humidity are in place ahead of a moderately strong cold front that will work across Southern Manitoba through the day. It looks likely that storms will initiate on the front fairly early in the day (perhaps even by late morning if nocturnal storms don’t just march out of North Dakota and continue through the day) and pose the risk of becoming severe as they will have ample energy available to them.

High CAPEs combined with ample bulk shear (0–500mb bulk shear values are expected to be in the range of 50–60kt) will allow storms to organize quickly and introduce the threat for large hail and strong winds. Shear values are generally running parallel to the front, which means slow frontal motion could produce training thunderstorms that may produce localized flash flooding. The threat for tornadoes looks fairly low given that winds right near the surface may not be able to move into a favourable direction due to the orientation of the front and tilt of the entire system. While tornadoes can never be ruled out of severe thunderstorms, at this time it doesn’t look like the threat should be considered one of the primary threats for Friday.

The day may be more cloud than sun depending on how convection develops to our south and west on Thursday night, but we should see a high temperatures anywhere from 25°C to 28°C before the front comes through. The passage of the front will bring northerly winds which will flush out a lot of the humidity that will have built up over the prior days which should make things quite a bit more comfortable. Things will clear out overnight as we drop to a low in the mid-teens.

The Weekend

Looking ahead to the weekend, we’ll see plenty of sunshine return with highs climbing in the 27–30°C range with comfortable humidity. It looks great. Keep tuned here and to our team on Twitter (@WeatherInThePeg, @steinbachwx and @lovestormsMB) for updates and thoughts on Friday’s severe weather potential. Until then, enjoy summer!

Stormier Weather Ahead

Brad Leave a comment

Rainfall expected on Monday night.

Rainfall expected on Monday night from the RDPS.

Unsettled weather will mark the start of the week as multiple disturbances move through Southern Manitoba in quick succession. A weak trough will push across the Red River Valley late this afternoon and through the early evening associated with a low pressure system moving through Northern Manitoba. That will quickly be followed up by a disturbance moving out of North Dakota through Southern Manitoba as well.

Today

Monday

28°C
Mainly sunny.
Monday Night

18°C
Increasing cloud. Rain with thunderstorms likely overnight.

Most of the day will be pleasant today as mainly sunny skies dominate and the temperature climbs to around 28°C. Clouds will develop a little later in the day as the trough line approaches and we’ll see a slight risk of a thunderstorm in the evening. At the same time as our slight risk of a thunderstorm, a more organized area of thunderstorms will be developing in North Dakota supported by an upper-level disturbance. This area of storms looks to expand into an area of rain with a few embedded thunderstorms as it moves northeastwards into Southern Manitoba and will likely bring rain with a decent chance of some storms through the overnight period to the Red River Valley. The rain could be quite heavy at times, with accumulations potentially reaching the 2” (50mm) mark. There’s still a little disagreement in the models regarding the development of this system, so we’ll be sure to keep an eye out in case it looks like this rain won’t develop. With how things look now, it seems likely that the rain would reach Winnipeg late overnight and move off by mid-day on Tuesday.

Tuesday

Tuesday

23°C / 13°C
Showers tapering off by the afternoon then clearing.

We’ll see a cloudy start to the day with showers likely as long as the convection in North Dakota develops as expected. They could still be quite heavy at times in the morning, so we’ll probably be off to a very wet start to the day. Things should taper off as the main support for the rain pushes into Northern Ontario by the early afternoon hours and then we’ll see sunshine work it’s way out. A few hours of afternoon sunshine should help push our temperature up to around 23°C by late afternoon. On Tuesday night we’ll see mainly clear skies with temperatures dipping to 13°C as we move into a slightly cooler air mass.

Wednesday

Wednesday

28°C / 15°C
Sunny.

Wednesday will mark the turnaround back into a hot weather regime. Sunny skies will dominate as we climb to a high of 28°C with fairly light winds. The sunny, warm weather will be thanks to a upper-level ridge building into the Prairies. We’ll drop to a low around 15°C on Wednesday night under clear skies.

Rest of the Week

The rest of the week will be increasingly hot as a southerly flow redevelops over the eastern Prairies and begins bringing Gulf moisture northwards into the region again. This will be marked by daytime highs near 30°C and increasingly humid air building into the Red River Valley. We’ll have more details on Wednesday, but at this point it looks like the second half of the week and the weekend will be marked by hot, humid sunny weather with a low risk of seeing any stormy weather.