Saturday, March 31, 2012

Warmest March on record ends on sunny warm note

Sunshine and warm temperatures capped a fitting end to March 2012 as temperatures once again soared well into the upper teens Saturday. In Winnipeg the high of 18.8C Saturday was just 0.1C off the record high of 18.9C for the 31st, set back in 1963. The balmy finish however propelled the monthly mean temperature in Winnipeg to +2.2C, easily the warmest March on record in the city since records began in 1872. The month was a whopping 8.3C above normal (30 year normal = -6.1C) and 0.6C above the previous warmest March of +1.6C set back over 130 years ago in 1878.

Top 5 warmest Marches in Winnipeg (since 1872)

1. 2012 .......... +2.2C
2. 1878 .......... +1.6C
3. 1910 .......... +1.0C
4. 1973 .......... +0.5C
5. 2000 .......... -0.1C

Normal .......... -6.1C (1971-2000 normal) 

A historic 12 day March heat wave through mid month was responsible for the record breaking month, which helped set all time March records throughout southern Manitoba and a wide swath of central North America into the Great Lakes. The heat wave obliterated Winnipeg's 25 cm snowpack in just a few days between the 10th and 14th, with temperatures more typical of early May between the 11th and 23rd. The month set 8 new daily record highs in Winnipeg, including all time warmest March temperature of 23.7C on the 19th. The warm spell also helped kick start the growing season by a full 3-4 weeks.. a concern for plant growers worried about a return to more typical freezing temperatures in April and May.

A look at past history shows that their concerns are indeed warranted as a warm March does not necessarily translate into a warm spring. In fact, of the past 9 previous warmest Marches in Winnipeg, only 4 were followed by above normal temperatures in April, and ALL had below normal temperatures in May! Those springs had an average of 20 freeze days in April, and 9 in May with frosts well into mid to late May (even the first week of June some years!). And if history is our guide, don't put away the snow shovels just yet. Of those past 9 warm Marches, all were followed by some measurable snow in April (including a 25 cm snowstorm April 15-17, 1910), and 4 had snow in May. So don't let the warm start to spring fool you.. this is southern Manitoba after all, and a warm March is no guarantee that cold weather is over.

Saturday, March 24, 2012

Some seasonably chilly weather.. then more rain for Monday afternoon into Tuesday

It may have come as a shock to residents of southern Manitoba, but after two weeks of record breaking warmth that saw temperatures more typical of early May, "normal" March weather felt anything but. Temperatures today struggled near the freezing mark all day, with gusty northwest winds and overcast skies. It was the coldest afternoon temperature in Winnipeg since March 9th which had a high of -4C. For tonight, cloudy to partly clear skies will allow temperatures to drop below -5C, our first subfreezing night since the 15th. Dry but cool conditions are expected to cap off the weekend Sunday, before clouds thicken again Monday ahead of the next major system that will affect southern Manitoba. This next system is expected to track across North Dakota Monday night into Tuesday, bringing some widespread rainfall across the RRV and southern Manitoba. Early estimates of rainfall are around 10-20 mm for Winnipeg Monday afternoon into Tuesday, with potentially higher amounts in some embedded thunderstorms which may accompany the system Monday night into Tuesday morning.

Cold front moving through Red River valley this morning with some rain and freezing rain..

A sharp cold front crossing southern Manitoba is bringing in much colder air this morning with temperatures dropping dropping below the freezing mark on gusty northwest winds. The front is accompanied by a band of rain that will be falling in subfreezing air, resulting in a period of freezing rain this morning as it passes through. About 5-10 mm of rain has fallen with the band with even some isolated thunderstorms occurring. The ground is warm enough from the mild temperatures of the past two weeks that significant icing should not be a major problem.. however some icing is possible on bridges and overpasses as well as sidewalks so be aware of the potential of some slippery conditions as you head out this morning. The band of rain will end by mid morning with drier air this afternoon, however temperatures will be back to normal values for this time of year.. which will be a bit of a shock after the abnormal warmth of the past two weeks. Seasonable temperatures will continue Sunday with mainly sunny skies, before milder but wet conditions move in by Tuesday.

Wednesday, March 21, 2012

Staying mild through Friday.. turning cooler this weekend with some rain possible

The well above normal temperatures will continue for a couple more days this week, before we get a cool down this weekend along with a chance of some showers. Temperatures are expected to climb towards the 20C mark again by Thursday, which if reached, would be the third 20C day recorded this month, matching the total number of 20C March days in the past 140 years. Increasing clouds Friday will give way to a chance of showers Saturday as a cold front pushes through, with cooler conditions in the single digits for Sunday. In fact, temperatures will only be dropping to normal values for this time of year.. but then, you'll have to forgive people if they've forgotten what normal is over the past couple of weeks. Temperatures are expected to be back above normal values for the last week of March, which will likely head into the record books as the warmest March on record in Winnipeg since records began in 1872.

UPDATE: Thu March 22: A record high of 21.7C was recorded today at Winnipeg airport, breaking the day's previous record high of 18.3C from 1878. It was the city's 8th record high in the past 12 days, and the third day this month of at least 20C.. equalling the total number of 20C days recorded in Winnipeg in March in the past 140 years. Note also that all 20C days this month occurred earlier than any previous 20C readings.

20C days in March - Winnipeg (since 1872)

1. 23.7C ..... Mar 19 2012
2. 23.3C ..... Mar 27 1946
3. 22.8C ..... Mar 23 1910
4. 21.7C ..... Mar 22 2012
5. 20.9C ..... Mar 18 2012
6. 20.6C ..... Mar 28 1938
* 19.9C ..... Mar 16 2012

* Note: Winnipeg had a high of 19.9C on Mar 16th this month, narrowly missing another official 20C day by 0.1C. For all intents and purposes however, one could consider that another 20C day, in which case it can be argued that Winnipeg had more 20C days this month than in the past 140 Marches combined. (note that before Canada went metric, temperatures were measured in deg F, which were converted to metric equivalents in 1975. A temperature of 19.9C before 1975 would have been recorded as 68F, which would have been converted to 20.0C when we went metric)

Monday, March 19, 2012

Thunderstorms mark fitting end to warmest March day on record..

Golf courses in full swing in
Winnipeg - March 18 2012
(Winnipeg Free Press photo)
The earliest thunderstorm on record in Winnipeg (since 1953) marked a fitting end to a summerlike final day of winter over the Red River valley.. as record breaking temperatures soared into the 20s along with gusty southerly winds and summer like humidity. In Winnipeg, the temperature peaked at 23.7C Monday afternoon, the warmest March day in the city since records began 140 years ago in 1872. The reading beats the previous warmest March day of 23.3C set over 65 years ago on March 27 1946. It was also Winnipeg's 5th consecutive daily record high, and the 7th in the past 9 days since this historic warm spell began on March 11th. The day also established a new record high minimum temperature for March, with a low of +13.3C at YWG airport.. the only time on record with a March low temperature in the double digits (previous warmest low was +7.8C on March 25 1945.)  In addition, the day featured summerlike humidity with dewpoints of 16C much of the afternoon, with a peak HUMIDEX reading of 28C at 3 pm in  the afternoon. These likely represent the highest such values ever recorded in March in Winnipeg.

List of record highs in Winnipeg : Mar 11 - 22, 2012

Date... REC HIGH (year) - Winnipeg Airport (data since 1872)

Sun 11 ..... 12.8C (2012) (prev 12.5C 1981)
Mon 12 ..... 9.7C (2012) (prev 7.2C 1922)
Tue 13 ..... 12.2C (1902) (11.7C 2012)
Wed 14 .... 11.4C (1981) (10.2C 2012)
Thu 15 ..... 14.4C (2012) (prev 11.1C 1927)
Fri 16 ...... 19.9C (2012) (prev 12.4C 1981)
Sat 17 ...... 19.2C (2012) (prev 12.8C 1938)
Sun 18 ..... 20.9C (2012) (prev 14.4C 1910) *earliest 20C reading on record*
Mon 19 .... 23.7C (2012) (prev 18.9C 1938) *new all time March maximum*
Thu 22 .... 21.7C (2012) (prev 18.3C 1878)

Temperature graph from my
weather station in Charleswood
March 19 2012
This warm spell has been one for the record books. Between March 11th-22nd, Winnipeg set 8 new record highs, including 3 days above 20C. In the previous 140 years of records, the 20C mark has been reached on only 3 occasions in March in Winnipeg (once each in 1910, 1938 and 1946). In other words, it took only 5 days during this warm spell to match what took 140 years to accomplish. Truly extraordinary. The warm spell has shattered records for March warmth throughout southern MB, the US plains, Great Lakes and eastern North America both in terms of extremes and duration. See blog entries from Jeff Masters, Chris Burt and A Weather Moment for more insight into this memorable weather event.

Sunday, March 18, 2012

Winnipeg sets new mark for earliest 20C weather. All time March high expected Monday..

Another day, another record.. Winnipeg's high of 20.9C today set a new record high for the day, easily smashing the day's previous record high of 14.4C set back in 1910. In fact, the record was broken by 10 am when the temperature at Winnipeg airport was already at 15C. It was the 6th record high in the past 8 days in Winnipeg, one of the longest record breaking warm spells on record. Today also set a new milestone for Winnipeg.. the earliest occurrence of a 20C temperature reading since records began in 1872, beating the former early mark of March 23 1910 when the mercury hit 22.8C. Simply put, it's never been this warm this early in Winnipeg in the past 140 years of weather records.

Cloud cover this afternoon today however prevented the city from reaching the next milestone.. the all time warmest temperature for March, currently a 23.3C reading on March 27 1946. However, it appears that mark may be eclipsed Monday as the warm spell continues for one more day over southern MB. After a record breaking mild night tonight (a low of 14C is forecast which would be the warmest March low on record), balmy south winds and sunshine on Monday should allow temperatures to climb to 25C by early afternoon, which would be the warmest March day on record in Winnipeg. Showers and even some thunderstorms are possible by Monday night as a cold front approaches, heralding the end of this historic March warm spell.

Saturday, March 17, 2012

Warmest March day on record forecast Sunday

Record books have been taking a beating the past few days as a historic March warm spell over the past week rewrites temperature records across southern MB and much of the central US. Winnipeg has recorded 5 new daily record highs since last Sunday, smashing previous record highs by as much as 6-7C yesterday and today. Incredibly, even warmer weather is forecast Sunday into Monday as a southerly flow pumps a summerlike airmass into southern MB with temperatures soaring into the 20s. The forecast high in Winnipeg Sunday is 26C, which would set a new mark as the warmest March temperature ever recorded in the city since records began in 1872. (Winnipeg's current all time high for March is 23.3C set back on March 27, 1946) The warm weather is forecast to persist into Monday as southerly winds continue with temperatures again in the 20s but an increasing chance of showers and even some thunderstorms. Cooler weasther is forecast Tuesday through the rest of the week, although still above the normal high of 0C for this time of year.

Thursday, March 15, 2012

Warm spell threatens all time records for March warmth

The current warm spell affecting central North America will threaten some all time records for March warmth over southern Manitoba over the next few days. In Winnipeg, daily record highs are likely to be set over the next 5 days, starting with today with a record high of 13C forecast, 2C above the current mark of 11.1C set on this date in 1927. The warmth really starts cranking up on Friday, with brisk southerly winds sending temperatures up to the 20C mark over southern Manitoba. If Winnipeg hits 20C or higher Friday, it would mark the earliest date on record that the city has ever hit the 20C mark, a full week earlier than the current mark of March 23, 1910 (22.8C) It would also be only the 4th time on record that the city has hit the 20C mark in March, and the first occurrence in over 65 years. (UPDATE: Official high temperature Friday was 19.9C.. just missing an official 20C day, but it's the earliest we've ever hit 19C)

20C days in March.. Winnipeg (since 1872)

1. March 27 1946 ... 23.3C
2. March 23 1910 ... 22.8C
3. March 28 1938 ... 20.6C

A slight cool down is forecast for Saturday, but temperatures are still forecast to be at record levels in the mid teens. Another push of warm air Sunday into Monday is expected to send temperatures into the 20s across southern MB, including Winnipeg where the all time March high of 23.3C in 1946 will be threatened. A cold front pushing through Monday night into Tuesday will bring cooler air, along with showers and possibly even the season's first thunderstorm of the year. All in all, looks like a potentially historic March warm spell on tap over southern Manitoba.

Sunday, March 11, 2012

Records melt in March warm spell..

An unseasonably warm airmass over southern Manitoba produced several record high temperatures today, including Winnipeg where a high of +12.8C was recorded, besting the previous record for March 11th of 12.5C set in 1981. Other records today included a toasty 14.8C in Pinawa (prev record 13.2C in 1995) and 14.6C in Melita. The MB hot spot was Wasagaming in Riding Mountain Natl Park at 15.8C. The record mild weather is forecast to continue through the rest of the week, with highs of +9-16C expected through Saturday along with a rapidly diminishing snowpack. In fact, it's possible that Winnipeg may see a string of record highs through the entire week!

Date... REC HIGH (year) - Winnipeg Airport (data since 1872)

Sun 11 ..... 12.8C (2012) (prev 12.5C 1981)
Mon 12 ..... 9.7C (2012) (prev 7.2C 1922)
Tue 13 ..... 12.2C (1902) (11.7C 2012)
Wed 14 .... 11.4C (1981) (10.2C 2012)
Thu 15 ..... 14.4C (2012) (prev 11.1C 1927)
Fri 16 ...... 19.9C (2012) (prev 12.4C 1981)
Sat 17 ...... 19.2C (2012) (prev 12.8C 1938)
Sun 18 ..... 20.9C (2012) (prev 14.4C 1910)
Mon 19 .... 23.7C (2012) (prev 18.9C 1938)

Saturday, March 10, 2012

Spring has sprung!

The well advertised change to spring-like weather this weekend has commenced over southern Manitoba, with temperatures of 5-10C across the region this afternoon under beautiful blue skies. The warm temperatures and strong March sun are resulting in a rapid snow melt, with snow cover disappearing quickly over parts of southern MB. The warmest temperatures today are across southwest MB and the western RRV where snow cover is less, as well as forested areas which can warm up faster in the spring due to better solar absorption than snow covered surfaces. As of 3 pm today, Portage, Pilot Mound and Pinawa were the provincial hot spots at 11C, while Winnipeg airport was up to 6c. Even warmer temperatures were found south of the border with 16C in Minot ND, 18C in Jamestown and an amazing 22C in Bismarck! Well above normal temperatures will continue the rest of the week, with temperatures reaching double digits over most of southern MB as the snowpack continues to melt.

Monday, March 05, 2012

Snow spreading into southern MB.. risk of freezing rain overnight and Tuesday morning

A storm system over southern Saskatchewan will be spreading an area of snow into southern Manitoba tonight into Tuesday, especially over the Riding and Duck Mtn regions where snowfall warnings have been issued for 10-20 cm of snow. Snow is likely mainly north of the TransCanada into the Interlake regions, while areas along and south of the TransCanada will see a risk of freezing rain overnight into Tuesday morning as warmer air aloft spreads into the region. A cold front trailing from this system will push across southern MB late Tuesday ushering in colder air Tuesday night into Wednesday.

Sunday, March 04, 2012

Light snow this morning.. more snow possible Monday

An area of light snow will be pushing across Winnipeg and the Red River valley this morning bringing a general dusting to 1 or 2 cm. This system will move out this morning, leaving partly cloudy skies for this afternoon into tonight. An Alberta clipper system is forecast to develop overnight into Monday and track along the international border, bringing a swath of more significant snow across the Yellowhead highway corridor of Saskatchewan into the Dauphin and Interlake areas where 5-10 cm of snow is possible Monday into Tuesday (see attached RGEM image showing 12 hr snowfall amounts between noon and midnight Monday Mar 5th). Winnipeg may see a few cm out of this system as well, however at this point, indications are the bulk of the snow from this system will occur mainly north of the city.

Thursday, March 01, 2012

Some snow on the way tonight into Friday

A low pressure system over northwest North Dakota will track along the international border tonight into Friday, bringing some snow to southern MB. Snow will spread into SW Manitoba this afternoon and move into the RRV tonight. Snow will likely persist into Friday morning before tapering off in the afternoon. Snowfall amounts from this system are expected to range from 2 to 4 cm along the TransCanada corridor including Winnipeg, to 5-10 cm towards the international border. Colder conditions are expected this weekend in the wake of this system, before a return to milder weather early next week.

Updated storm totals: (March 2)

Snowfall was a lot more than expected with this storm system.. with amounts of 10 cm over Winnipeg and the northern RRV and up to 20 cm over the southern valley. Some snowfall totals reported over the past 24 hours..

Winnipeg.......... 10-12 cm
Stony Mtn ........ 9 cm
Landmark ........ 10 cm
Steinbach ......... 10 cm
St Labre ............ 16 cm /SE of Steinbach/
Winkler ............. 19 cm
Morden ............. 15 cm
Altona ............... 15 cm
Pinawa.............. 12 cm
Falcon Lake ...... 6 cm