Wednesday, September 21, 2011

After the deluge.. turning warm and dry through the end of September..

After Tuesday's soaking rains which brought 25 to 75 mm of rain to the RRV, conditions will be turning dry and warmer the rest of this week through the weekend and into next week. A large upper ridge of high pressure will build over the Prairies bringing a prolonged stretch of sunny dry and warm weather over central Canada over the next week or so, including southern Manitoba. After a frosty night tonight, temperatures will rebound into the mid teens Thursday with light winds, then into the mid 20s over the weekend as warmer air spreads in. Long range models are indicating the dry and warm weather should continue over southern Manitoba through the end of the month. Fall officially arrives this Friday, so it looks like a nice warm and dry start to autumn. Enjoy!

Sunday, September 18, 2011

Rain by Tuesday.. windy and warmer by end of week

The new week will start off on a dry and mild note with sunshine and temperatures rising into the low to mid 20s. Unsettled weather however will move in overnight Monday into Tuesday with occasional rain and possible thunderstorms, along with gusty northwest winds and cooler temperatures. Models are hinting that rainfall may be heavy at times Tuesday over portions of southern Manitoba and the RRV, with 20-40 mm possible in some areas. This system is expected to clear out by Wednesday as a ridge of high pressure builds in over southern Manitoba. This will be followed by increasingly windy and warmer weather by the end of the week into the weekend as the ridge moves east and a return southerly flow sets up over southern Manitoba. Gusty south winds will allow temperatures to rise to above normal values in the mid 20s by Saturday. The autumnal equinox arrives this Friday the 23rd.

Wednesday, September 14, 2011

Widespread freeze tonight.. warmer weather for end of week into next week

The first blast of fall like weather pushed into southern Manitoba yesterday, resulting in below normal temperatures, gusty north winds, lake effect precipitation and frost over parts of southern Manitoba this morning. Well below normal temperatures continued today with brisk northwest winds keeping temperatures only near 10C this afternoon. For tonight, a ridge of high pressure over Saskatchewan will build over southern Manitoba bringing clearing skies and light winds. This will lead to a widespread freeze over southern Manitoba by Thursday morning, with overnight lows of -1 to -4C forecast in most areas. (Downtown Winnipeg and areas along the MB lakeshores should escape the freeze tonight) The first frost over Winnipeg and the Red River valley usually isn't until the third week of September, so this year's first frost is arriving about a week earlier than normal. Sunny and milder weather will develop Thursday into Friday as the high pressure ridge pushes east and we get into a moderating southerly flow. A frontal system pushing in from the west threatens showers for Sunday.

Cold outbreak brings first lake effect of the season over southern Manitoba

The first cold outbreak of the season brought some lake effect showers yesterday through last night into this morning off the Manitoba lakes, with a few narrow bands of significant precipitation to the southeast of the lakes. Most of the precipitation fell as rain thanks to the 18C lake waters, however precipitation was mixed at times with ice pellets or graupel and even some wet snowflurries in some areas. The radar image to the left shows a 6 hour precipitation accumulation between 3 am and 9 am, and nicely shows how the main lake effect bands were oriented, with a NNW flow of 330-340 degrees bringing narrow bands of precipitation off Lake Manitoba and Lake Winnipeg. The bands produced 5-15 mm of rain off Lake Manitoba through the High Bluff-Elm Creek areas, about 5 mm in the Pinawa region, and 10-15 mm near Fischer Branch. 850 temps of -4C were moving over 18C lake waters to produce the lake effect, which was generally cellular and disorganized during the day, becoming more pronounced overnight. The bands weakened during the day Wednesday as a ridge of high pressure built in from the west.

Tuesday, September 13, 2011

Falling temperatures, lake effect precipitation and frost.. fall weather pushing into southern Manitoba today..

A cold front through central Manitoba this morning will push south today, ushering in a flow of unseasonably cold air from Northern Manitoba southward. This front will be accompanied by a few showers as it moves across southern Manitoba around midday today, followed by gusty northerly winds and falling temperatures this afternoon. The flow of colder air over the warm lake waters of the Manitoba lakes will likely set up some heavier bands of rainshowers off Lake Winnipeg and Lake Manitoba later today into tonight, with narrow bands of locally heavy precipitation possible mainly east and west of Winnipeg. Strong northerly winds of 50-70 km/h will also cause large waves and rising water levels along the south shores of the lakes today into tonight. Things should settle down Wednesday as high pressure drifts across southern Manitoba easing winds and weakening lake effect precipitation. This area of high pressure however will likely produce the season's first widespread frost across southern Manitoba Thursday morning with temperatures of 0 to -3C likely in many areas including the Red River valley.

Saturday, September 10, 2011

Record heat possible today.. fall like weather arriving early next week..

The long hot dry summer of 2011 continues today over southern Manitoba with another 30C+ day on tap.. our 4th in a row in Winnipeg, and the 23rd occurrence of 30C or more temperatures this year. Several record highs are likely again today over southern Manitoba, including Winnipeg where 1998's mark of 32.4C set on this date in 1998 is in jeopardy. Another summerlike day is expected Sunday with temperatures in the upper 20s, not quite as hot as today as we get into a light northeast flow of somewhat cooler air.

Big changes are on the way though as we get into Monday and Tuesday. A cold front will push through southern Manitoba Monday with clouds and a chance of showers, with gusty northwest winds developing bringing in cooler air. By Tuesday and Wednesday, high temperatures will only be in the low teens along with clouds and brisk northwest winds along with some lake effect showers off the Manitoba lakes. High pressure will build in by Wednesday and Thursday which will likely produce the season's first widespread frost to southern Manitoba. Moderating temperatures are expected by the end of the week into next weekend as temperatures return to more normal values for this time of year (around 20c). So enjoy the warm weekend.. this could be summer's last hurrah!

Saturday, September 03, 2011

Beautiful first week of September ahead

Cool unsettled weather over southern Manitoba today will give way to clearing skies and more pleasant conditions Sunday as a ridge of high pressure builds in from the west. Temperatures Sunday will still be a couple degrees below normal for early September, but lighter winds and more sunshine will result in a more pleasant day than Saturday. The ridge will move east of the province on Labour Day resulting in a southerly flow of warmer temperatures in the low 20s for the last day of the holiday weekend. The rest of the week looks fabulous as an upper ridge builds over the Prairies allowing sunny skies and increasingly warmer air to build over southern Manitoba through the upcoming week. Look for sunny skies and mid 20C temperatures as the kids head back to school Wednesday with temperatures rising into the upper 20s to near 30C by Thursday and Friday. The summer of 2011 ain't over just yet!

Thursday, September 01, 2011

5th driest summer on record at Winnipeg

The summer of 2011 will go down as the 5th driest summer on record in Winnipeg since records began in 1873. The 93.0 mm of rain recorded at YWG airport from June through August was over 140 mm below the 3 month summer average of 235 mm, about 40% of normal. The summer was the driest since 2006 when 91.5 mm was recorded. The dry weather took hold by the last week of June, which carried through the driest July on record (10.0 mm) into a drier than normal August (37.5 mm) Between June 23rd and August 18th, there were no daily rainfalls greater than 5 mm at YWG airport as convective storms evaded the city, much to the delight of sun worshippers, but to the dismay of farmers who saw crops wither in the hot and dry weather. The dry weather however was not widespread over southern Manitoba. Southwest MB and the southern RRV experienced more normal amounts of rain during the summer, with the driest conditions mainly over the northern RRV and eastern MB.

Top 5 driest summers - Winnipeg (since 1873)

1. 1929 ........ 76.7 mm
2. 1886 ........ 77.2 mm
3. 1961 ........ 91.0 mm
4. 2006 ...... 91.5 mm
5. 2011 ....... 93.0 mm

Temperature wise, the summer of 2011 had a 3 month average of 19.5C.. about 1C above average (18.5C) and the warmest summer since 2006 (19.8c) The 19.5C summer average tied it for Winnipeg's 17th all time warmest summer. The bulk of the heat was during July and August which were 1.7C and 1.8C above normal respectively. The summer saw 19 days of 30C or more, including 8 in July and 9 in August. Cool spells were minor and fleeting, and were quickly replaced by sunny warmer weather. The hottest temperature was a record setting 37.2C on August 23rd, while the coolest was a 3.8C reading on June 9th.

Top 5 hottest summers in Winnipeg (since 1873)

1. 1988 ............ 21.0C
2. 1983 ............ 20.8C
3. 1961 ............ 20.4C
4. 1955 ............ 20.2C
5. 1963/1930 ....... 20.1C