Sunday, January 28, 2007

Another Arctic blast by late week

Temperatures will remain seasonably cold for the next few days over Southern MB with highs generally in the minus teens and lows in the minus 20s. Long range guidance however is indicating another shot of very cold Arctic air that is expected to flood into the Prairies by Thursday or Friday (Feb 1-2) that will bring daytime highs in the minus 20s and lows in the minus 30s along with dangerous wind chill values in the minus 40s. The bitter cold is expected to persist through next weekend into early next week after which a moderating trend is expected.

Wednesday, January 24, 2007

Colder air set to return by Friday

850 mb prog - 6 am Friday morning

Enjoy the relatively mild weather today and tomorrow.. because things are going to get colder again starting Friday. A storm system moving across the northern Prairies over the next couple of days will sweep a cold front across southern Manitoba early Friday morning. Gusty northwest winds behind the front will draw colder Arctic air across the region, with temperatures falling Friday into the minus teens by afternoon. The cold air will become well entrenched over the weekend with highs only around minus 20 and lows in the minus 30s. Temperatures are expected to remain below normal next week into early February as a strong upper ridge over the West Coast gives mild weather over the west while a deep upper trough over Eastern Canada maintains cold air over central and eastern Canada.

Tuesday, January 23, 2007

Thursday, January 18, 2007

CPC forecasting milder than normal conditions into February

The latest 30 day outlooks from CPC (US Weather Service) have been issued, and they continue to show a better than even chance of milder than normal temperatures for February over the Prairies (top image). In fact, CPC's 6-14 day outlooks are also calling for milder than normal weather for us to finish off January, so the recent cold snap we just went through may be the worst of it this month, or even this winter. (However, cold snaps will still occur, even if the overall pattern is milder than normal.. so don't put away that block heater just yet!)

The milder than normal conditions expected over the next month or so is again in sharp contrast to Environment Canada's latest 30 day outlook (lower image) which calls for below normal temperatures across much of the country into mid February ( a complete flip from their above normal forecast issued two weeks ago). This is not surprising given the the outlook was issued during our mid January cold snap, and EC's outlooks are heavily weighted to current weather patterns. They are also completely automated model-driven products with no human intervention whatsoever. As a result, EC's outlooks tend to be more of a persistence forecast (what's happening now will continue to happen) and can be poor indicators of any major pattern changes expected within the next 30 days. In contrast, CPC's outlooks have a great deal of human involvement in them, looking at overall climate patterns and influences in the near and mid terms, which can lead to more accurate long range outlooks.

Personally, I think the overall weather pattern over the next 30 days is going to favour milder than normal conditions over western Canada with below normal temperatures over Eastern Canada as the NAO turns negative and maintains a large scale trough along the eastern seaboard. For southern MB, this will mean a battle of two airmasses.. alternating between milder Pacific airmasses that will occasionally move in from the west while Arctic intrusions from the north give periods of below normal temperatures. Overall temperatures may be close to normal over the next 30 days, but perhaps more variable with mild and cold episodes balancing each other out.

Monday, January 15, 2007

Warming up by Wednesday.. then colder again

It's another frigid morning over Southern MB with temperatures of minus 30 to minus 35 in Winnipeg this morning (-34 at my Charleswood station) Luckily winds are light today, so windchills are not a factor. Still, even walking at these temperatures will be enough to give exposed skin frostbite within a few minutes.. so bundle up!

Temperatures will start to moderate beginning tomorrow, with noticeably milder conditions on Wednesday with highs climbing back into the minus single digits by then (break out the sunscreen!) Before that however, we will have to deal with a blustery Tuesday as gusty south winds begin developing ahead of the milder airmass. So don't be fooled by Tuesday's forecast high of minus 10.. that's quite misleading as to what kind of day it will be. First of all, that high of -10 (if we even reach it) won't be reached until late in the day or evening. Temperatures will be in the minus 20s all morning and in the minus teens all afternoon. Second, those gusty southerly winds of 40 to 50 km/h with higher gusts will add a significant wind chill.. minus 35 to minus 40 in the morning moderating to minus 25 to minus 30 in the afternoon. In fact, Tuesday will feel just as cold as today even though actual temperatures are a good 10 degrees colder today (but winds are light.. it's all about the wind!)

Unfortunately, the milder temperatures on Wednesday will be short lived as colder air moves in again by the end of the week. Beyond that, temperatures are expected to remain generally below normal for the rest of January with occasional brief warm ups as a large scale upper ridge builds over the west coast, while an upper cold trough digs over Ontario and eastern Canada. This will give a northwest flow over the Prairies that will give Southern MB generally below normal temperatures for the next couple of weeks.

Friday, January 12, 2007

Frigid Friday

Baby it's COLD outside.. officially -37C at the airport this morning with a wind chill of -50! Ouch! It's the coldest temperature in Winnipeg since Jan 2005 when we hit -38.6C. Last year, the coldest we ever got was -33.7C on Feb 17, so this is definitely the coldest it's been around here in awhile. Looks like the cold will last through the weekend into early next week.. but then long range guidance is indicating another push of Pacific air coming in by next Wednesday with milder temperatures over Southern MB again.. so hang in there! Until then.. bundle up and stay warm!

Monday, January 08, 2007

Above normal warmth to end by week's end..

It's been an incredibly mild run over southern MB with above normal temperatures every day since Dec 8th .. that's 32 consecutive days above normal in Winnipeg as of today. However, a major change in the weather pattern is expected by the end of the week as a strong storm system moves across the Prairies. A strong push of Arctic air is forecast to flood across the Prairies behind this system with temperatures of minus 20 or lower moving into Alberta by Wednesday.. Saskatchewan by Thursday and Manitoba by Friday. This will be the first significant push of Arctic air over the Prairies in over a month which will feel especially cold given the prolonged warmth of the past 4 to 5 weeks. The Arctic airmass is expected to continue into next week, so be prepared for some real winter weather to finally arrive..

Wednesday, January 03, 2007

Record mild January day

What a beautiful day out there!!  Sunny skies and balmy southwest winds have raised temperatures up into record territory today, with an afternoon high of +5C in Winnipeg, beating the former mark of 3.3C set in 1880 and 1984. It's even warmer west of Winnipeg with Portage hitting a record +8C!  The above normal temperatures are expected to continue through the rest of the week before a cooldown to more normal temperatures over the weekend into next week. In fact, CPC's long range outlook calls for below normal temperatures over western Canada and the Prairies over the next week or two.   

Tuesday, January 02, 2007

December 2006 Highlights


It was a mild and dry December over Winnipeg and Southern Manitoba, and other than a month end snowstorm, the month was very quiet with little in the way of precipitation or major weather systems. The month began on a cold note with below normal temperatures during the first week which saw temperatures dipping to a monthly low of -27C on the 3rd. From the 8th on however, every day was above normal, resulting in a monthly mean temperature some 6 degrees above normal (-8.6C compared to an average December of -14.4C) This marks the 8th December in the past 10 years that have seen above normal temperatures in the Winnipeg area. The mild December also marked the 10th month of the year that featured above normal temperatures, capping one of the mildest years on record in Winnipeg, with 2006 ranking as the 5th mildest year since records began in 1872.

Precipitation during December was virtually non existent until a month end snowstorm that dumped up to 30 cm of snow in Winnipeg during the 30th to 31st. Other than that, there was very little in the way of snow with only 8 cm of snow falling in minor snowfalls over the first half of the month. In fact, no precipitation was recorded at all from the 17th until the 30th, resulting in ideal weather and travelling conditions for the Christmas holidays.

All in all, a mild and dry December capping a warm and dry 2006.

Monday, January 01, 2007

Rob's Obs 2006 stats

Here are some year end statistics and extremes recorded at my weather station in Charleswood for 2006..

Max temperature: 35.5C (Jul 12)
Min temperature: -32.8C (Feb 17)
Mean annual temp: 5.6C (2.8C above normal) (officially, 5th warmest year on record in Winnipeg)
Total rain: 203 mm (202 mm below normal, or 50% of normal rainfall.. one of the driest years on record)
Total snow: 151 cm ( 36 cm above normal)
Max 24hr rain: 17.8 mm (Sep 17)
Max 24hr snow: 29.0 cm (Dec 30-31)
Max wind gust: 61 km/h (79 km/h adjusted) from the North (Oct 13th)

Highest barometric pressure: 1045.3 mb (Feb 17)
Lowest barometric pressure: 988.7 mb (Nov 8)

Highest dewpoint: 22.9C (Jul 30)
Highest humidex: 44C (Jul 30.. 35C air temp with 22c dewpoint)
Lowest relative humidity: 21% (April 24.. 10C air temp with -11C dewpoint)

Overall, the main story for 2006 was the dryness and warmth.. 10 out of 12 months were warmer than normal including the warmest January on record and the second warmest April. Pecipitation was at a premium with below normal rainfall for every month of the growing season (April through September) culminating in one of the driest years on record in Winnipeg since records began in 1872.