Tag: Warming Up

Warming Up, Just to Get Knocked Back Down

Brad Leave a comment

Temperatures will rebound early this week, but a big weather-maker may interrupt that warm-up by midweek.

Warmer air will move into Southern Manitoba on Monday, but it will be windy.

Monday

Monday

Sunny
21°C / 9°C

Today will be bright and sunny with temperatures improving over Sunday’s cool values. Highs will be in the low twenties over Southern Manitoba, which is quite a recovery from this morning’s lows, which were around freezing. The only downside to today’s weather will be a stiff southerly wind that will be 30 to 40km/h gusting to 50 to 60km/h by late afternoon.

Tuesday

Tuesday

Mainly Sunny
27°C / 13°C

Tuesday will be one of the warmest, if not the warmest, days this week with high temperatures in the mid to upper twenties. The humidity may even increase a bit by late in the day over some portions of Southern Manitoba. It certainly won’t be an oppressive mid-summer type of humidity, but may be noticeable nonetheless. Tuesday will be slightly less windy compared to Monday, but the wind will still be fairly strong and from the south.

Wednesday

Wednesday

Mix of Sun and Cloud. Rain late. Risk of a thunderstorm.
25°C / 17°C

What has been a fairly boring weather pattern so far this September may begin to take an interesting turn on Wednesday. A strong low pressure system is forecast to develop in the lee of the Rockies on Tuesday and move eastward into North Dakota by Wednesday. This system will prompt seasonably high moisture values to stream northward into the Dakotas and Southern Manitoba. This moisture will help to destabilize the atmosphere over a large part of the North-Central US, perhaps extending up into Southern Manitoba. This system will also pump warm air up into the region, with models currently suggesting temperatures will once again reach the mid to upper twenties in Southern Manitoba on Wednesday.

As this strong low pressure system interacts with that unstable environment, numerous thunderstorms may develop on Wednesday through Wednesday night. These storms may affect parts of Southern Manitoba at some point on Wednesday or early Thursday. Given the nature of this system it looks like the main severe threat will be heavy rain. However, it is too early to rule out the possibility of other forms of severe weather. We’ll have more updates on this system as the week progresses.

Long Range

The long range forecast will largely be determined by what happens with Wednesday’s system. At this point it appears likely that we’ll receive rain from this system, but the timing of that rain is too early to predict. Unfortunately, once this system moves out of our area it will deliver a parting shot of cold air, which will probably set up a chilly weekend. Again, how cold it will get is still not certain, but getting above seasonal values next weekend may be a struggle.

Gradual Warm-Up on The Way!

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Omega Block over Eastern North America

500mb heights/winds on Friday night depicting the Omega Block over Eastern North America.

Southern Manitoba has been under the grip of below-normal temperatures yet again over the past couple days, but a shift in the storm track will allow warmer air to build into the region. A large omega block, pictured above demonstrating it’s namesake (the wind flowing around the blocking pattern looks like the greek letter omega: Ω), will inhibit eastwards motion of the large-scale pattern, so the big question is: when exactly is it going to warm up? Fortunately, it’s not going to take too long.

Large-Scale Pattern Shift

Typically when blocking patterns set up, weather remains rather stagnant for a lengthy period of time: the rain stays in more or less the same place (it’s forecast to rain for most of the next 6-7 days in eastern portions of Iowa) and the sunshine remains over similar places. In extreme cases, features such as Omega Blocks can result in catastrophic flooding or droughts as similar conditions persist for weeks on end.

Fortunately, that won’t be our story. The blocking pattern is slowly decaying, but the real driver for our change in temperature will be the future of the upper trough currently over Manitoba/Northwestern Ontario. It’s simple existence is quite an anomalous feature and has only been able to maintain it’s existence by a continual reinforcement of Arctic air. Over the next few days, though, the northern storm track is going to become more active as disturbances begin to ripple through the NWT and Nunavut. These features will strengthen the upper-level winds north of 60° and cut off the reinforcing cold air.

Without this cold air injection and with the sun continually climbing higher in the sky, the cold air in our upper trough will quickly be modified out. As the northern storm track becomes more active, the flow aloft across the Northern Prairies will become more zonal as well, which will help bring warmer air into the region, although an upper ridge is forecast to build in over the Southern Prairies, keeping our winds fairly light aloft. So what does all this mean?

Friday

11°C / 0°C
Sunny
Saturday

14°C / 3°C
Sunny
Sundy

18°C / 8°C
Sunny

What will be happening over the next few days, effectively, is the “bottling up” of winter once again, locking it north of a strong jet stream running through the Northern Praires/Southern Arctic. Warmer air will slowly build back into the region with temperatures returning to normal or just above normal by the end of the weekend. In addition to the warming temperatures, we’ll see nothing but sun sun sun!

Next Week

The trend looks to continue through next week, with temperatures climbing into the low 20’s and more sunshine prevailing. The next chance for any sort of precipitation looks not to be until maybe the end of the week. A warm, dry week will be good news for the flood situation in Southern Manitoba.

Warmer Weather Set to Return to The Red River Valley

Brad Leave a comment

After a prolonged and sudden stretch of normal to below-normal temperatures, warmer weather is on it’s way for Winnipeg.

500mb Winds valid Wednesday Evening

500mb wind speeds valid for this evening. Of note is the advancing upper ridge (denoted by the blue squiggle) over British Columbia.

The long-wave trough that has remained solidly parked over the Eastern Prairies over the past week is finally pushing off to the east, allowing a building upper ridge over British Columbia to spread eastwards into the Prairies and bring with it some milder Pacific air. With an incoming upper ridge, our chance for precipitation over the next few days is pretty much nil. We’ll see temperatures climb to about 17°C today, which will be a couple of degrees above our normal daytime high of 15°C for this time of year. Things warm up on Thursday as a warm front pushes through and we climb to a high of 23°C. Temperatures will remain in the low 20’s right through the weekend under sunny skies.

A Dry End to September

Rob put up a great summary on the precipitation situation for Southern Manitoba this month.

As of [September 24, 2012], only 4 mm of rain has fallen at Winnipeg airport this month, with no precipitation forecast all this week through the end of the month. If so, September will end up as the 2nd driest September on record in Winnipeg since records began 140 years ago in 1872.

I highly recommend you head over and read the brief summary Rob put up. It continues to look like we’ll be dry through the end of the month, so there’s a very good chance that Winnipeg may see it’s second driest September on record. We’ll have a complete summary for the month of September on Monday, October 1st in addition to our regular post.

A Chance To Dry Out A Little Bit…

Brad Leave a comment

After a deluge of rain over the past 10 days, Winnipeg is finally set to see some sunny, dry weather. A high pressure system pushing through the area will provide sunny skies over the next couple days with daytime highs pushing back towards our normal high of about 22°C.

Winnipeg has had 46% more rain than normal since April 1

Winnipeg has had 46% more rain than normal since April 1. (KEN GIGLIOTTI / WINNIPEG FREE PRESS)

Winnipeg is absolutely soaked. So far this month, many areas of the city have seen over 100mm (3.94”) of rain, with some areas of the west end seeing closer to 125mm (4.92”). This is a huge amount of rain for a single month in Winnipeg; the Manitoba Agricultural Department released a report showing that Winnipeg has had 46% more rain than normal over the last 30 days. This wetter-than-normal month has broken a 9-month stretch of dryer-than-normal conditions for Winnipeg and the city has already shattered last year’s total summer precipitaiton. If summer is considered June, July and August, our 100-125mm of precipitation in Winnipeg this month trounces the 93mm we got through Summer 2011. In addition, through summer last year only 7 days had thunderstorms reported. So far in May alone, we’ve had 5 days with thunderstorms. All in all, we’re off to a wet start to the summer that’s already been more promising on the storm front than last year.

Over the next couple days, though, we’ll see the sun. A ridge of high pressure will move across the province today, bringing sunny skies, light winds and a high near 19°C. The high begins to move out of the region on Thursday, allowing a slight southwest flow to bring some warmer air for the day, allowing our daytime highs to climb just over 20°C under sunny skies.

We’ll see a slight chance of showers on Friday afternoon as a warm front pushes through the Red River Valley, bringing temperatures in the mid-20’s for the weekend.