Monday, September 28, 2009
Chilly today.. frosty tonight...
No, that's not a Wendy's menu order.. that's the weather forecast for Winnipeg and southern Manitoba for the next 24 hours as a northerly flow of cool air spreads over the province. Gusty north winds today will keep temperatures only in the 12c range this afternoon, with cloudy skies and occasional sprinkles or drizzle from weakening off lake streamers. For tonight, high pressure will be building over southern MB, bringing clearing skies and diminishing winds.. perfect conditions for frost formation overnight. In fact, much of southern MB will see its first frost of the season by Tuesday morning with overnight lows of zero to -3C expected. The exception will be areas near and to the west of the MB lakes which will be saved from frost by the warm lake waters. Patchy cloud cover will also save some localities from frost tonight. Tuesday looks like a nice day with sunshine mixing with a few clouds, lighter winds, and afternoon temperatures of 12-15C.
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I've heard that the temperature at ground level can be as much as 4 C colder than the temperature 6 ft off the ground!!
ReplyDeleteLeading to a frost even when the air temperature.... say at the airport is +4C
Waterspout reported over Lake Winnipeg South Basin?
ReplyDeleteScott, SK was at about minus 6 this morning. Lots of places in the -4 to -5 range. Waterton Park, AB was at about -8.
ReplyDeleteSaskatoon Airport was around -2 but most of the city escaped frost. Tender plants are still alive.
Here's some interesting info:
ReplyDeleteThe Victoria Beach weather station recorded its lowest temperature for September 2009 this morning. +12 C. Now that's tropical! The average low this month has been 16.6 C, about the same as for Rome, Italy.
Those Victoria Beach residents might not have noticed with the 60Km winds and 1.5 meter waves last night and early this am
ReplyDeleteThis is a rude welcome back to NORMAL conditions...when the storms of November come early Lake Superior winds 70-75 km with gusts near 100Km near noon.with Waves to 3.5meters. In some places they are still increasing..
Justin..
ReplyDeleteThere was a pilot report out of St Andrews of a waterspout over the south basin of Lake Winnipeg this morning. There was a line of lake effect TCU at the time which may have induced the waterspout. That was the only report..
Will be interesting to see who gets frost tonight in the and around the city depending on wind flow and local micro-climate. Our northerly wind this evening will drop off and become a light northeast flow overnight. This will advect milder air from the downtown core towards western and southwestern parts of the city, which may protect these areas from frost. Even the airport may not get as cold as it could have been if the wind remained from the northwest tonight. Eastern parts of the city may get a harder frost tonight than the west. We'll see..
ReplyDeleteVery interesting cloud pattern noted on visible satellite... NE flow could allow for patchy lake effect clouds to reach Winnipeg from time to time tonite. Also good stratus deck noted west of the city likely benefiting from some upslope enhancement along Manitoba and Pembina escarpment.
ReplyDeleteThe key being that the high pressure centre remains well north. Counter-radiation from remnant stratus will cause wide temperature variations tonite.
The other saving grace may be that the ridge line will be east of RRV by dawn giving us a light SE flow. Therefore I think best for a wide spread hard freeze will be in SE Manitoba chance where:
1) there is already good clearing present
2) they will be away from any lake influence due to easterly wind trajectory
3) ridge line will be directly over the region by 7 am
Further west areas may be affected by higher level clouds advecting over stratus remnants.. will be interesting to see what happens.
Well just got home from work and checked the temperature !
ReplyDeleteAlready -0.2 as of 3:00 am.
Mind you that is at the airport!
TWN has a windchill (or Feels Like) reading of -4 as of 4AM. When was the last time we had a humidex reading, was it only last Thursday or Friday?
ReplyDeleteNo frost within the city of Steinbach, but out at the airport there is a light frost, with temps around -1C.
ReplyDeleteNot much frost in Charleswood.. a little on the roofs and cars but that's about it. My low was +0.5C, so the growing season is still going here. A low of -2.4C at Winnipeg airport offically ends the growing season for Winnipeg. The Forks downtown had a low of +1.4C. Most places in the RRV and SE MB got frost this morning, with southwest MB escaping due to cloud.
ReplyDeleteI see environment Canada lists the windchill temperature even when winds are below 10 km/h.
ReplyDeleteI'm sure it used to be the winds had to be over 10 km/h!~
Rob!
ReplyDeleteThe winds that Regina is getting today....could those winds be that strong in Southern Manitoba tomorrow????
If I remember correctly, the Windchill formula used in North America works once the wind is above 4.8km/hour
ReplyDelete115 day growing season...is that the Norm for Winnipeg??
ReplyDeleteAlmost 4 months frost free..what a climate we have. ..GF Dan should move here?
ReplyDeleteWith (If) an Airport high of 13.1C today we can post our 29th consecutive September day of above average Mean temps.
ReplyDeleteOne month of great weather melted my memory banks. Who'd a' thought late Sept AVERAGE is damn cold.
.
At Winnipeg airport, the average date of the first fall frost is Sept 22nd so we were a week later than "normal" although that first frost date varies quite a bit from year to year. Average date for the last frost in spring is May 23rd which gives an average growing season of about 121 days using airport data.
ReplyDeleteThis year we had a late freeze on June 6th, giving Winnipeg airport a frost free season of 114 days, a week shorter than average. Last year, the airport had a 116 day growing season (Jun 3rd - Sept 26th), virtually the same as this year.
Downtown, the growing season is much longer, averaging some 159 days or 38 days longer than the airport. The average first fall frost downtown is Oct 5th, while the last spring frost is May 4th. This is due to the urban heat island effect that keeps night time temperatures warmer than rural areas. For most other areas of the city, the length of the growing season lies somewhere between downtown and the airport values.
Jim..
ReplyDeleteMax of 11.9C at Winnipeg airport today after a low of -2.4C, giving a daily average of 4.8C. That's our first day below normal since Aug 30th.. 4 straight weeks above normal! Now that's a streak I like!