More Rain to Come

     A very slow-moving cold front last night in the RRV helped trigger one of the biggest rain events of the year in Winnipeg. A heavy thunderstorm remained stationary over central and southwestern parts of the city for over an hour. Generally 40-80 mm of rain fell from Charleswood to Whyte Ridge to dowtown. Much lower amounts fell in southeastern, eastern and northern parts of the city where amounts ranged anywhere from a trace mm to 30 mm. I received 16 mm here in River Park South. Here are some amounts from yesterday via Cocorahs, Weatherfarm, Environment Canada and other backyard stations (Robsobs, Kyle, Matt and myself) (including the rains from the morning):

Community	Rainfall total August 21, 2014
Whyte Ridge	60-84 mm
Bridgwater Forest	70 + mm
Lindenwoods	57-66 mm
Downtown (UofW)	64.8 mm
St James	50.6 mm
Charleswood	41.9 mm
Old St Vital	29-31 mm
South St Vital	17.9 mm to 31 mm
Wpg Int’l Airport	20.6 mm
Transcona	5-7 mm

    Considering the normal August rainfall in Winnipeg is 79.2 mm, some parts of the city saw a month's worth of rain in just 2 hours. It's no mystery that there was major road-flooding last night. The rain is also on top of another heavy rain event in the Lindenwoods area  (30-40 mm) back on Monday.

     It was also extremely moist/humid yesterday. With a maximum dewpoint observation of 21.5°C at the airport at 6:00 pm, we were just shy of a dewpoint record (old is 21.7°C in 1969). However, the minimum dewpoint observation yesterday was just 17.2°C, a record high minimum for the day. Old record high minimum dewpoint was 15.1°C in 1981.

     Unfortunately, the gloomy weather continues. Cloudy skies are expected today and tomorrow with minimal breaks in the cloud. A bit of drizzle or light rain may fall at times before the big rain event tomorrow night.

More rain is on the way

     A strong low pressure system moving up from the United States will bring a widespread rain event to southern Manitoba late tomorrow into Sunday. At this time, it appears the bulk of the rain will begin tomorrow evening for Winnipeg and last until Sunday morning. The rain may be quite heavy at times and there may be a few embedded thunderstorms. 15-30 mm or more could fall throughout the RRV and southeastern Manitoba, including Winnipeg. Localized amounts up to 40 mm are possible under the heaviest bands and if any thunderstorms do occur, but most areas will see less than that. Stay tuned in the comments below for updates.

     Scattered showers with embedded thunderstorms remain possible through the afternoon and evening on Sunday. There could even be some sun, allowing temperatures to reach low 20's. Generally cloudy skies look to continue Monday with a few showers possible at times. Chilly, fall-like conditions look to continue through to mid-week before things begin to warmup by the end of the week.

Enjoy the Warmth While it Lasts

     Turned out to be quite the thunderstorm event in the Winnipeg area last night. The south end of the city, especially south of Bishop Grandin, was hardest hit. Long-lived torrential downpours dumped 20-30 mm of rain to this part of the city in just 20 minutes or so. Lighter rainfall amounts in other parts of the city with generally 5-15 mm. Ongoing rains and lightning after the main storm dumped an additional 5 or so mm.

     Here at my place in River Park South, I received 26.7 mm in total last night. Only 11 mm fell at the airport. Here are a few rainfall totals from yesterday and overnight today:

Portage southeast (cocorahs) 38.1 mm
Portage (Mb Agriculture) 35.2 mm
Winnipeg South St Vital 25-35 mm in general
Carman 29.4 mm
St Adolphe 25.7 mm
Portage Southport 16.1 mm
Winnipeg The Forks ~ 15 mm
Winnipeg Charleswood 11 mm

     I've also got a brief video below just for the memories (nothing overly special)... not much visual, mainly audio. I managed to catch a couple impressive thunderclaps, the first was following a close cloud-to-ground strike which you can faintly see in the video. Note the torrential rain... it was heavy like that for perhaps 15 minutes in general.

     A few scattered showers are possible today. Another thunderstorm cannot be ruled out, but nothing like what we saw last night. They will be more isolated in nature today. Due to cloud cover, we'll likely only reach low 20's.

     Enjoy the warmth tomorrow and Wednesday! Lots of sun tomorrow with a high around 26-28°C. A mix of sun and cloud for the first part of Wednesday with a high possibly reaching 30°C (depending on cloud coverage). Increasing cloud late in the day on Wednesday associated with an approaching system and cold front. Showers and thunderstorms look likely early on Thursday with this.

     At this point, it appears the active pattern continues into next weekend. Both the GFS and GEM models hint at a strong low pressure system affecting us Saturday-Sunday with the potential for a significant rainfall. However, note that the ECMWF is not so keen on this idea. As a result, still lots of uncertainty about next weekend. A significant cool down looks likely behind the system for early-mid next week. Too early to say how long it will last. Needless to say, enjoy the warmth while it lasts!