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


  1. All major guidance pointing to a system coming through southern MB next Monday with a good bet for showers and storms, possibly with some locally significant rainfall. So that "sunny" forecast for Monday?... yeah, I wouldn't put too much faith in that working out right now. Don't be surprised to see that forecast flip to something more pessimistic in the days ahead.

    1. All guidance still pointing to a good soaking for Winnipeg/RRV Monday with 10-30 mm possible. EC forecast only calling for a 30% chance of showers.. which is odd given that even EC's own model guidance (GDPS) is giving Winnipeg at least 18 mm of rain through the day. Not sure why that is.. but expect Monday forecast to become increasingly pessimistic based on current model consensus.

    2. Well, EC finally joining the party and calling for straight out showers Monday, with a high of 21C (so much for that 27C) So it took 3 days to catch onto something models were indicating all along quite consistently. Note that EC long range forecasts are automated from model output but are also subject to post processing algorithms that sometimes detract from model guidance.