Frosty to Start the Week

Brad Leave a comment

We’ll be in for a couple of chilly, perhaps you could even say frosty, days to start this week. Cool daytime highs and sub-zero nighttime lows are on tap.

GEM-REG 3hr. Precipitation Accumulation

Some light lake effect showers (shown in blue) are expected to develop on Monday as cold air flows over the relatively warm lakes winnipeg and manitoba.

After a rather chilly Monday morning, temperatures won’t make a dramatic recovery for the afternoon. Daytime highs on the first day of the week are expected to barely make the double digits in most areas, with highs generally in the 9-12C range expected. A breezy north wind and perhaps a couple of lake-effect showers won’t make the day any more pleasant. Tuesday night should be another cool one in Southern Manitoba. However, it appears frost will be isolated to areas around and east of the Red River Valley as some warmer air moving in from the west will keep temperatures above zero overnight in Western Manitoba. Daytime highs on Tuesday will be an improvement from Monday, though except for South-Western Manitoba where 20C values are expected, temperatures will generally remain stuck in the mid teens.

Yet another cold front will swing through overnight Tuesday into Wednesday ushering in another cool airmass to end the week. It appears high temperatures will be relegated to the teens from Wednesday through Friday. There appears to be slim odds of any significant precipitation this week, though we may at least get some measureable rain later in the week as a few strong impulses rotate through the region.

NAEFS Ensemble 8-14 day outlook

The NAEFS ensemble doesn’t give a strong indication of what type of weather we’ll see moving forward…

At this point the long range forecast looks fairly status quo. We’ll see some cooler than normal days and some warmer than normal days, but in general the pattern for the next week or two generally looks to be near normal on average. However, there will certainly be a fall feel to the air as nighttime temperatures regular drop down to the freezing mark and daytime highs stay close to the average high for mid-September of 18C.

Elsewhere in Weather News: September 15th, 2012

Matthieu Leave a comment

Pakistan Monsoon Flooding

Severe flooding occurred in Pakistan early this past week, after monsoon rains moved into the region and dropped large amounts of rain. Even though Pakistani officials had issued a flood warning for many low-lying areas such as Punjab and Sindh, many residents decided to stay put to battle out the floods in their villages.

As numerous canals and rivers overflowed their banks because of the heavy monsoon rains, many low-lying areas such as farmland, villages and roads were inundated with water. The highest rainfall report that could be found was in Rahimyar Khan where 193mm fell in 24 hours between Sunday the 9th and Monday the 10th.

Pakistan flooding

Two satellite images (visible/IR enhanced) showing the difference between no flooding and severe flooding in Pakistan. Notice the dark blues along the Indus River. (Source: NASA)

About 1,500 houses were destroyed in the process and over 100 people perished with waters rising quickly and houses collapsing from waters. The country’s army was deployed to execute search and rescue missions in the hardest hit areas, and to try to fill in the areas where water broke through the canals.

Flooding

Picture showing the flooded houses in the town of Larkana located in the region of Sindh. (Source: APP)

Estimated total losses look to be in the neighbourhood of a couple million, though it’s difficult to assess at this time as authorities are still tallying up the damages and looking for survivors. When the floodwaters recede, most likely in a couple days, the final tally from the total economic loss and death toll should be more accurate. This monsoon season does not compare to 2010 though, where numerous severe flooding events occurred and residents described that year as “the worst in living memory”. In 2010 the total structure damage that accounted for four billion in damages and the floods had a significant impact on 20 million people with around 2,000 deaths.

The monsoon rains have since moved away a couple days ago from the region of concern and crews will be able to clean up, repair villages and search for more survivors this weekend.

Mainly Seasonal With A Chance of 30°C

Brad Leave a comment

We’ll see fairly typical weather for this time of year across Winnipeg and the Red River Valley with a big exception being tomorrow: with southerly winds and a big upper ridge moving across the region, there’s a good chance we’ll see temperatures in the upper 20’s, perhaps even breaking 30°C on Saturday afternoon.

500mb Wind Speed

500mb wind speed from the GEM-REG for midday today depicting the upper ridge that is moving into the province.

We’ll see plenty of sunshine today as the aforementioned upper ridge begins working it’s way into our region. Temperatures will be able to climb up much higher than yesterday, where a cool air mass combined with clouds limited our temperatures. We’ll see a high near 25°C today, although it will be a bit of a climb as we dig out of a rather chilly morning.

On Saturday, the upper ridge will move across the province, bringing with it 850mb temperatures in the 17-18°C range. Winds will be out of the south, not the southwest, so we won’t see any significant downslope effect to help our temperatures out. As a result, we’ll see widespread highs near 28°C with a few locales getting as high as 29 or 30°C by the late afternoon.

A powerful cold front will dive southwards through the Red River Valley on Saturday evening which will usher cool Arctic air in from the north. 850mb temperatures will plummet to nearly 0°C for Sunday which will hold our daytime high to the mid-teens, most likely below the seasonal normal high of 18°C, under cloudy skies.

Cooler air will continue to push southwards into the beginning of next week, with 850mb temperatures dropping below 0°C on Monday and remaining over the region for much of the week. This will likely result in daytime highs in the mid-teens and overnight lows in the low single-digits for much of the week under more cloud than sun and a chance of showers on and off through the week.

Strong Winds Blast Southern Manitoba

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Strong winds will blast across Southern Manitoba today as a very powerful low pressure system crosses Northern Manitoba. The winds will also usher in an unseasonably cool air mass that will give us a very chilly night before the upper ridge begins to rebound into our region.

850mb Temperatures for Thursday morning from the GEM-REG

850mb temperatures for Thursday morning from the GEM-REG. A cold trough of 850mb temperatures between 0-1°C will rest over the Red River Valley and Whiteshell, contributing to unseasonably cold overnight lows.

A powerful low pressure system with a central pressure of approximately 984mb is pushing across Northern Manitoba and will bring a very strong pressure gradient across the Red River Valley today that will usher in 50-60km/h winds with gusts as high as 80km/h. This system has a history of producing very strong winds; on Monday it brought widespread winds in excess of 100km/h to Southern Alberta and yesterday it brought winds between 80-110km/h through Saskatchewan and Northern Manitoba.

The winds will pick up in the Red River Valley this morning and we’ll see several hours of fairly strong westerly winds. Unlike regions to our west that had to deal with the winds for a fairly prolonged period of time, the winds will move through the region fairly quickly as the low accelerates out of Northern Manitoba into Hudson Bay. As a result, winds should let up noticeably by the evening.

In behind this system, fairly cold air will sweep across the province. Across the Red River Valley, overnight lows will be kept a little warmer by some light winds expected to continue through the night. Through the Red River Valley, overnight lows will generally drop to 3-5°C tonight, however if any areas see the wind let up, it would certainly be possible to see overnight lows dip to 1-2°C under clear skies and calm winds. The most likely area for this to happen, though, is a little further east in the Whiteshell where the trees will help protect the surface from light synoptic winds.

Temperatures will return to seasonal on Thursday as an upper ridge begins to build eastwards across the Prairies. We’ll see a mix of sun and cloud across the Red River Valley with a very slight chance of a shower as warmer air begins to push into the region. Daytime highs should be near 19-20°C on Thursday with overnight lows on Thursday night once again rather chilly in the 4-6°C.

Warm air moves back in for the weekend, with plenty of sunshine and highs near 25°C on Friday and Saturday. Things look to cool off a bit on Sunday as another cold front passes through.