Saturday, July 25, 2009

Cool week to end cool month..

After near seasonal temperatures this weekend, another spell of below normal temperatures will be ushered into southern MB Monday, which will continue through the end of the month. High temperatures for the upcoming week are forecast to remain around 20C each day.. a good 5-6 degrees below normal for late July. This will ensure that July will end up cooler than normal in Winnipeg and southern MB.. making it the 8th consecutive month with mean temperatures below normal. Such a streak has happened only twice before in Winnipeg since 1971.. from Nov 1978 to June 1979, and from Oct 1995 to May 1996. Meanwhile, a huge upper ridge building over BC will maintain hot dry conditions over the province with temperatures of 35-40C through the upcoming week.

Monday, July 20, 2009

Still no hot weather in sight..

Hot summer weather continues to elude much of central Canada including the eastern Prairies as a strong upper ridge of high pressure persists over western Canada producing a northwest flow of cooler air for us. The result has been consistently below normal temperatures this month over southern MB with hot weather confined to western Canada, including the Okanagan interior of BC where forest fires are currently raging. (see 30 day temperature graph for YWG)

Not much change is expected for the rest of the month with the upper ridge expected to persist over BC (see attached 500 mb GFS prog for Friday) maintaining warm temperatures out west with near to below temperatures over the eastern Prairies. Although the absence of hot humid weather is a disappointment for beach and cottage goers in southern MB, the weather has been comfortable for most residents with the benefit of little or no need of air conditioning. As of July 19th, the mean monthly temperature in Winnipeg was 15.8C, putting it on pace for one of the coolest July's on record in the city since records began in 1872. The top two coolest Julys in Winnipeg were 1884 (15.4C) and 1992 (15.9C) Both those years followed major volcanic eruptions the previous summer (Krakatoa in 1883, and Pinatubo in 1991)

Thursday, July 16, 2009

Fall like weather to give way to nice weekend..

It’s a cool wet July morning out there with overcast skies, rain and temperatures only around 9C.. making it feel more like fall than mid summer.  A low pressure system over northern Ontario is bringing a gusty northwest flow of unseasonably cool air over southern MB today, along with occasional rain and drizzle. The air is even cool enough to generate enhanced bands of lake effect rainshowers to the southeast of Lakes Manitoba and Winnipeg today. The clouds and rain will keep temperatures only in the low teens at best today.. some 10-15 degrees below the normal high of 27C for mid July, the warmest time of the year in southern MB. Cloudy cool weather will persist tonight into Friday morning before skies begin to clear out by afternoon or evening as a ridge of high pressure over Saskatchewan builds into the province. This ridge will bring a much nicer weekend for us with sunny skies and more seasonable temperatures in the mid 20s.

Wednesday, July 15, 2009

Heavy rain swamps Winnipeg.. again..

For the second time in five days, thunderstorms brought heavy rainfall to Winnipeg, with particularly heavy amounts over the west end. The heavy rain swamped drainage systems, and led to extensive street flooding and waterlogged properties in west Winnipeg (see photo here of Buckle Drive in Charleswood). Last evening, heavy downpours began around 6:15 pm in Charleswood, and continued through 8 pm. At my site, I recorded 42 mm during the evening downpour (peak rainfall intensity 155 mm/hr) , on top of the 20 mm that fell with showers earlier in the day, for a daily rainfall of over 60 mm. Winnipeg airport recorded 45 mm yesterday, with 26 mm falling during the evening downpour. This comes on the heels of a heavy downpour last Thursday that dumped over 50 mm at my site (35 mm at the airport) Scattered showers will persist today across southern MB, but amounts will be light. Thankfully, a trend to drier and warmer weather is forecast over southern MB by the end of the weekend into next week.

Sunday, July 12, 2009

Nice today and Monday.. more showers/tstorms Tuesday and Wednesday

We've got some nice weather to enjoy today and tomorrow with sunshine, light winds and temperatures in the low to mid 20s. Things will get more unsettled Tuesday as another storm system pushes into the Northern Plains bringing a band of showers and thunderstorms into southern MB by Tuesday morning. Conditions are favourable for some severe thunderstorms to develop over Montana and western ND Monday evening, pushing into southern MB as a band of locally heavy thunderstorms overnight Monday into Tuesday morning. Models are indicating the potential for locally heavy rainfall with these storms over portions of southern MB overnight Monday into Tuesday morning, with local amounts of 30-50 mm possible. Additional showers and thunderstorms are likely Tuesday afternoon with
more showers expected Wednesday across southern MB as the storm system moves east.

Thursday, July 09, 2009

Thunderstorms with torrential rain hit Winnipeg

A line of intense thunderstorms moved through Winnipeg Thursday morning between 9 and 10 am bringing torrential rain and pea size hail. At my site in Charleswood, my weather station recorded 48 mm of rain in about 45 minutes.. with a peak rainfall rate of 457 mm/hr at 9:41 am.. the heaviest rainfall intensity my station has recorded since it was set up in 2001. The extreme rainfall led to many problems in the city including flooded underpasses, downed power lines and water damage to the Victoria General hospital.

Tuesday, July 07, 2009

Severe thunderstorms, heavy rain possible Wednesday night

A storm system developing over Montana will track into the Dakotas on Wednesday, bringing an outbreak of severe thunderstorms over western and central North Dakota by late Wednesday. These storms will have the potential to bring large hail and damaging winds, with a few tornadoes possible. The strongest storms are expected in North Dakota, however a few severe thunderstorms are possible across far southern and southwest MB Wednesday evening with large hail and damaging winds as the main threat. Thunderstorms will continue to spread over all of southern MB Wednesday evening, bringing mainly heavy rain Wednesday night into Thursday morning with local amounts of 25 to 50 mm possible. Stay tuned on this developing severe weather situation with updates from NWS Grand Forks, SPC, EC and of course, Rob's Obs!

Monday, July 06, 2009

Thunderstorm tracks over east Winnipeg

Here's a great webcam shot of the thunderstorm cell passing over the east end of the city. Temperature dropped to 13C with heavy rain in the east, while the west end of the city didn't get a drop, but gusty outflow winds dropped the temperature from 24 to 19C in 20 minutes. East St Paul reported up to 21 mm of rain with the cell with pea size hail in Transcona.

New website for Rob's Obs

Well, after the problems I was having with the FTP server at Shaw, I decided to post a new website for Rob’s Obs. The former Rob’s Obs website address at will no longer be valid. That site will redirect you to my new site at This new site is a total redesign that’s been in the works for a few months, but I thought I’d launch it now given the FTP problems I was having with my old site. The new site has a cleaner, more professional look, and is faster to load than the old one with no annoying pop ups ( I hope!). And my weather station is updating data to the site again. So we’re back in business. Hopefully you find this new design an improvement over the old one.

Also note that jpg images from my site now have a “no_cache” added to the directory.. so if you have any links to Rob’s Obs .jpg images, be sure to add /no_cache after /robsobs to get the valid images.

Thursday, July 02, 2009

June 2009 weather stats for Winnipeg

After an unseasonably cool first half of the month, temperatures finally warmed to above normal values for the latter half of June as summerlike weather finally made an appearance over southern Manitoba. The warm weather however was not enough to offset the cool start, and as a result, June finished almost 1.5C below normal, with a monthly mean temperature of 15.6C at Winnipeg airport. This made June the 7th consecutive month with mean temperatures below normal (December 2008 to June 2009). Although significant this is not record breaking. Since 1971, there have been four other periods with 7 consecutive months of below normal monthly mean temperatures in Winnipeg, namely...

November 1973 to May 1974

June 1985 to December 1985

May 1993 to November 1993

November 1996 to May 1997

There were also two periods with 8 consecutive months below normal

November 1978 to June 1979

October 1995 to May 1996

The month was marked by an exceptionally late freeze on June 6th.. with a record low of -4.6C at Winnipeg airport.. the coldest June temperature ever at the airport since 1938, and the second coldest June temperature in Winnipeg since June 1 1888 (-6.1C) Downtown Winnipeg escaped the freeze with no frost reported at the Forks weather station. 


A strong storm system on June 26-27th brought heavy rainfall and strong winds to southeast Manitoba with over 100 mm of rain in areas east and southeast of Lake Winnipeg. This system brought heavy rainfall to eastern sections of Winnipeg with 75 mm reported while western areas, including the airport, had 35 mm. Other than this system precipitation was generally light in June with a lack of showers and thunderstorms. As a result, precipitation varied greatly across the city in June. Whereas the Airport only had 61.5 mm, the downtown station at The Forks had 82.8 mm and according to the rain gauge network operated by the City of Winnipeg, there was over 90 mm in the many areas of Winnipeg east of the Red River. Normal June rainfall in Winnipeg is 90 mm.