Thursday, May 31, 2018

City swamped with heavy rainfall - up to 75 mm reported in River Heights

A slow moving band of showers and embedded thunderstorms moved across the city of Winnipeg late Wednesday afternoon, resulting in a deluge of rain over much of the city. The heaviest rain moved in from the southwest around 4 pm, and proceeded to slowly track across the downtown core over the next 2-3 hours. By the time the rain tapered off in the early evening, amounts of 25 to 75 mm were reported across the city, the heaviest in the Tuxedo-River Heights area.  The heavy rain caused flash flooding of Winnipeg streets, with Pembina Highway temporarily closed due to flooding under the Jubilee overpass. By contrast, very little rain fell over southeast sections of the city with 5 mm or less over south St Vital into the Sage Creek area.

Rainfall map for city of Winnipeg based on unofficial Weather Underground
reporting sites up to 7:15 pm May 30 2018. Values in inches, contours in mm 

Official rainfall amounts for the event included:

Winnipeg Forks:  46.1 mm
Winnipeg airport: 26.3 mm 

Unofficial amounts included:

River Heights: 74 mm
Tuxedo: 69 mm
U of Winnipeg: 52 mm
Linden Woods: 25-40 mm
Charleswood: 28 mm (my site)
Whyte Ridge: 27 mm

The rainfall has made up for a very dry start to spring with virtually no rain through April into the first half of May.  As of today, May precipitation now sits at 54 mm for Winnipeg airport and 70 mm at the Forks. Average monthly precipitation in Winnipeg for May is around 60 mm.


Rainfall map from Weatherlogics using over 300 rainfall reports

Wednesday, May 09, 2018

Very dry weather continues.. Winnipeg closing in on top 5 dry spells of all time


The dry weather of the past 2 months continues into May, with no measurable precipitation recorded so far in the month. In fact, as of May 9th, Winnipeg has gone 27 consecutive days without any measurable precipitation. The last day with measurable precipitation in Winnipeg was on April 12th when 1.2 mm of melted snow was recorded at the airport. (measurable precipitation is defined as a day with 0.2 mm or more of melted precipitation (rain or snow)  With no significant precipitation expected through May 15th, this current dry spell may enter the record books as one of the top 5 longest dry spells in Winnipeg since records began in 1872. The chart above shows the top 5 longest dry spells in the city, the longest being 47 days without measurable precipitation in the fall of 1976. The longest dry spell in the spring (which is a more serious time for dry weather) was in 1980 when Winnipeg went 40 straight days without measurable precipitation.  How long this current dry spell will last is difficult to say at this point.. but increasingly it looks like it may become historic before it's finally over. The dry weather has caused major headaches for city firefighters who have had to battle numerous grass fires in the past few days in and around the city.     

UPDATE:  Well, the dry spell ended at YWG airport but there's a bit of a controversy over exactly when the streak ended.  Officially, the first measurable precip at YWG airport in May was on May 17th when 0.8 mm of rain fell. That would have put the dry spell at 34 days, tied with 1882 as the 4th longest dry spell on record.   However, it appears the official precipitation gauge at the airport (XWG CS station) was possibly under-reporting rainfall from the 15th through the 19th. A co-located rain gauge at XWG picked up 0.2 mm of rain on the 15th, as did many private stations in Winnipeg with some light rainshowers that day. If that's the case, the dry spell would have ended on the 15th for a streak of 32 days, which would be the 6th longest dry spell on record. Which is correct? I'm going with the latter (32 day streak) with 0.2 mm of rain on the 15th, not much, but just enough to break the precip-free streak.     

Thursday, April 19, 2018



Well, it took awhile, but it looks like spring has finally sprung in Winnipeg and southern MB as sunny skies and temperatures in the mid teens signalled the warmest weather here since last October (6 months ago!)   And the springlike weather is expected to continue this weekend with temperatures in the upper teens, possibly closing in on 20C in some localities!  The only fly in the ointment will be gusty southerly winds accompanying the warm temperatures over the weekend, especially Sunday with southerly winds gusting to 50-60 km/h. Otherwise, it'll be a great weekend to enjoy the outdoors like riding your bike, getting some swings in at the driving range, or starting on that spring cleaning! Temperatures are expected to cool off to around 7-10C Tuesday, but then should rebound into the upper teens to 20C by next Thursday again. So spring is here.. at least for the next little while! Enjoy! 

Sunday, April 01, 2018

Cold start to April.. spring slow to arrive this year

Those hoping for a quick transition to spring as the calendar switches to April are going to be disappointed as the Prairies remain stuck in a below normal temperature pattern for at least the next 1-2 weeks.  The colder than normal pattern will mean that an extensive lingering snowpack over the Prairies and northern Plains will be slow to disappear, making it even harder for warmer temperatures to surface. As a result, expect a slow and gradual melt this year.. likely leading to the latest snowmelt here since 2014. Precipitation over southern MB looks below normal as well as the main storm track sets up south of the international border, for this week anyways. Models are hinting of a more active pattern setting up next week over the southern Prairies which may bring some accumulating snow into southern MB again by early next week (ugh!)  

As of April 1st, the highest temperature in Winnipeg so far this year has been only +5.4C (March 27th) with no hint of double digits temperatures in the near future.  In comparison, Winnipeg had already reached double digits twice in March of 2017 (including 12.3C on March 29th), and another 10 times in the first 2 weeks of April 2017 (19.8C on Apr 8th). We'll need to lose a lot more snowpack before we see temperatures like that this year.  Note that normal highs in early April in Winnipeg are +5C, rising to +10C by mid month and 15C by April 30th.   

Thursday, March 01, 2018

Potent storm system to bring widespread snow to southern MB Sunday night into Tuesday

Surface weather map valid midnight Sunday night shows
system bringing widespread snow across southern MB
A potent storm system is forecast to develop over the central US plains later this weekend, and is expected to bring widespread snow to southern MB Sunday night into Tuesday. After a quiet winter that has seen very little snowfall (the lowest Dec-Feb snowfall in at least 30 years in Winnipeg), this upcoming storm system has the potential to produce the most significant snowfall of the season for much of southern MB, including Winnipeg. There's still a lot of uncertainty with how this storm will track and develop, but at this point, it's looking like a widespread snowfall of 15-30 cm is possible for many areas by Tuesday.

Preceding this main storm will be an initial system on Saturday that will bring a band of snow which will push across southern MB and settle into the Interlake region. This initial impulse may bring a couple cm of slushy snow to southern MB, but it shouldn't have much impact with temperatures around the melting point. Some rain may even mix in Saturday afternoon.

Things will start to get interesting by Sunday afternoon as the main storm system starts intensifying as it moves out of Colorado. This storm will track into Minnesota by Sunday night spreading a widespread area of snow across southern MB. The snow may be wet and slushy at first with temperatures hovering around the freezing mark Sunday through Sunday night. Snow could be heavy at times Sunday night into Monday as the storm system slowly pushes across Minnesota, with gusty northeast winds as well. This will make for treacherous driving conditions across southern MB Monday. Snowfall will linger into Tuesday before the system gradually winds down. As noted, snowfall amounts are still tough to predict this far out based on uncertainty in storm track and temperature profile, but in general, it looks like most of southern MB could be looking at 15-30 cm between Saturday and Tuesday night. The highest amounts would likely be over the western Red River valley with some upslope enhancement along the Pembina escarpment, but many areas have the potential to see significant snowfall with embedded bands of heavier snow. Stay tuned as more information becomes available on this developing storm system.