Thursday, September 20, 2012
Cold front Friday to usher in cooler airmass for first weekend of fall..
Things have cooled off over southern Manitoba this week as a northwest flow of cool air persists over the eastern Prairies. And things will get even cooler Friday into Saturday as a cold front pushes in from the north, ushering in the coolest airmass of the season so far, just in time for the first day of fall Saturday. The cold front is expected to push through Winnipeg from the north around midday Friday, accompanied by a few showers. Behind the front, northerly winds will increase gusting to 60 km/h, ushering in cooler air from the north with temperatures dropping into the single digits. In addition, the cool air over the 15C lake waters will generate bands of lake effect showers off Lake Winnipeg, and Lake Manitoba. Below normal temperatures are expected into the weekend before a gradual warming trend next week.
Posted by rob at 2:36 PM
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Most depressing headline of the year! Just as long as we don't get snow I suppose.ReplyDelete
Is that lightning throughout the night in the Interlake being produced by lake-effect streamers?ReplyDelete
Yes it is. A good band of lake effect is occurring off the north basin of Lake Winnipeg this morning with -2c air at 850 mb moving over 13c lake waters. Band will become disrupted today as cold front pushes through from the north, but then bands will become more 360 oriented behind the front with -5c cold core at 850 mb moving over the lakes, this afternoon into tonight. I would think this would support more vigorous lake effect bands, but models show minimal activity perhaps due to a bit more low level shear, and subsidence with approaching ridge fom the west.ReplyDelete
East-west cold front over southern interlake showing up nicely on radar and satellite images. Front will be pushing southward through today, likely moving across Winnipeg by early afternoon with a band of showers, possibly even a lightning strike or two. Winds become northerly and gusty behind the front with temperatures dropping into the single digits this afternoon. Multi-banded streamers off the lakes in northerly flow possibly merging into more intense single bands as winds become better aligned in low levels. Fall is arriving a day early!ReplyDelete
It's approaching now...dark skies off to the north with winds picking up.ReplyDelete
Wow...temperatures fell to 8.8 C at the airport.ReplyDelete
Heavy rain, strong winds, and falling temperatures here in Charleswood.ReplyDelete
Wow. Wind gust to 84 kmh at the airport!ReplyDelete
Impressive. It's down to some lighter rain and a few gusts in Westwood.ReplyDelete
Are these >80km winds always a regular feature of September in Winnipeg or does it just seem as if we're stuck in this pattern?ReplyDelete
FROPA - If the wind shift was the result of a frontal passage.ReplyDelete
Don't see that very often.
Winnpeg 7 CReplyDelete
Kenora 3 C
Red Lake 1 C
Melita 18 C
Regina 19 C
Edmonton 23 C
A real winter pattern and not even October yet..
There was intense ice coming down with that downpour in central Winnipeg early afternoon/near noon. Did anyone else get this? And anybody know if it was ice pellets or was it actually hail? The ice was the size of peas.ReplyDelete
Did anyone else see a very brief, light flurry in the south-central area of the city around 3:05pm or so? There was an approx. 50 second flurry of light flakes blowing around but not reaching the ground. Makes me wonder if our autumn will have more intense frontal systems as the effects of the low sea ice level plays catch-up.ReplyDelete
Rob you jinxed us.. Here's what you said in March...ReplyDelete
''Dan.. yes, it's been an amazing run, with a summerlike end to winter. I sure hope we don't pay for it with a winter like end to summer! :) ''
Ok maybe we didn't get a blizzard today, but a few snowflakes/ice pellets are as close enough to winter as I want to get.
Relax folks.. today was just an early preview of fall. (I didn't notice any flurries myself, but I did get a little small hail with that midday downpour) We still have some nice weather ahead, with moderating temps next week, possibly warming into the 20s later next week. In fact, CPC is indicating above normal temps for us over the next couple of weeks. Remember, we were 29C just last Saturday. We've had an amazing run, and a period of below normal temps should not be unexpected. Stay warm!ReplyDelete
Northerly flow off Lake Winnipeg bringing lake effect cloud over Winnipeg and areas east this evening, with even some light precip falling over eastern suburbs. That will delay the temp drop for us tonight, until the clouds start clearing off overnight. Temps will be falling faster west of Winnipeg where skies have cleared..ReplyDelete
Yikes... -5c at the airport as of 7 am. Nowhere near as cold everywhere else in the city with temps near freezing or slightly above (+1c at my place. +3 at the Forks). Really shows how localized that airport reading can be.ReplyDelete
Temperatures generally around -2 or -3C outside the perimeter.
There must something wrong with Halifax's airport rain gauge. It apparently measured 101 mm of rain yesterday, but most parts of the province seemed to have gotten closer to 5 to 15 mm.ReplyDelete
EC stopped uploading the data into the archive (the public web version) the other week, so I suspect there's a known problem there.ReplyDelete
Ohh ya should've guessed..ReplyDelete
Using furnace the first time this year this morning, was a col 15°C in the house this morningReplyDelete
If the recording station at YWG is not even representative of areas outside the perimeter, it needs to be moved. Its unfortunate that given the current political climate and lack of quality control, its not likely to happen. Its lucky we at least now have a network of stations from alternative sources.ReplyDelete
The recording station was moved some time ago to the more cold-prone site it currently resides in. This makes any analysis of trends in growing season difficult.. possibly obfuscating an important warming signal. Does anyone know when and from where it was moved? Would be interesting also to look for any trends in the occurrence of extreme/ record low temperatures after the re-location.
There is also a situation where for a city like Edmonton, forecasts are made specifically for the city.. whereas for Winnpeg they are generated for the airport. The justification being that the ceity centre airport was an official station. Hopefully with over 10 years of data from the forks site we will see some change.
A moved station which still meets WMO standards is still heads and tails above most any of the 'alternative' sources. Even ignoring siting standards, try finding one with a ventilated psychrometer, or an anemometer at 10m (only 1 other network has this). Some of these stations (government operated!) even have a tipping bucket rain gauge mounted on a wobbly mast, so rain in the windy conditions results in over-reporting. I've also seen promotional materials for the same network with the station mounted on a metal roof! If you this quality control is getting bad with EC, you'd be shocked at what some other networks consider acceptable.ReplyDelete
I checked out the wind on the WeatherFarm map during that last major blow, and nearly all of the non-EC stations had laughable wind speeds (some less than 10 km/h)!!
The situation with EC is less than ideal, but don't through the baby out with the bath water.
"If you this quality control..." = "If you think quality control..."
"don't through" = "don't throw"
Also replace "government operated" with "government sponsored". Most station networks actually operated by government agencies are fairly good (at least for their own intended purposes, if not beyond). However some have bought into privately operated networks in which website advertising revenue and other commercial interests seem to have taken priority over the actual obs.ReplyDelete
Daniel's point about forecasting for the city vs. the airport is interesting though.
In regards to automated station locations... at least the U.S. the automated sites are sited at airports due to FAA requirements. We use the data it provides, but the FAA is the main player in what it produces. The four ASOS's in Grand Forks forecast area (GFK, FAR, BDE and PKD) are maintained by NWS techs whereas the rest are maintained by the FAA (and in the case of the newer ND ones such as Langdon, Cavalier) maintained by a company in California.ReplyDelete
Another night with Winnipeg airport being quite a bit colder than anywhere else in the city. Down to -2C at YWG airport at 11 pm, while it's above freezing almost everywhere else in the city according to Weatherfarm and Wundergound obs.. including +1.4C at my place and +5C at the Forks. Even outside the perimeter temperatures are just above freezing.ReplyDelete
Winnipeg chamber of commerce would have an easier sell if they started using Forks data instead of YWG airport! (longer growing season, milder winters, less severe windchills, etc)
Dan.. Re: airport autostations. The same thing is happening here in Canada. Increasingly, airport weather obs in Canada are being relegated to our national aviation body (NavCanada), with EC having less and less control of the monitoring systems at airport locations. That's why it's becoming more and more difficult to get things like snowfall observations from our main sites (like Winnipeg) because NavCanada doesn't take them (whereas EC observers did). NavCanada is in the process of converting EC autostations at Canadian airports to NavCanada autostations, with EC increasingly relying on volunteer obs and 3rd party networks as additional sources of weather data to augment NavCanada controlled sites. Even COCORAHS expanded into southern MB this year, which hopefully can provide some good snowfall data over the winter.ReplyDelete
Note that snowfall data is still being measured at most major Canadian airport sites, with a contract agreement between EC and NavCanada for their observers to take snowfall obs. There are a few airports however that don't have such an agreement in place, including Winnipeg, Regina and Saskatoon unfortunately. So you have the rather bizarre situation where official snowfall obs in Canada are taken in places like Vancouver and Victoria BC, but not in cold weather cities like Winnipeg and Regina.ReplyDelete
Well, i guess our remarkable run of 14 consecutive months of above normal weather has come to an end this month with values likely to be below normal for SeptemberReplyDelete
I've noticed that it has been quite a bit warmer out west than here lately with temps in mid twenties in Alberta.
Any chance of temps climbing back to the twenties here in Southern Manitoba in the next week or so?
Models are showing a nice warmup by mid to late week with temperatures likely back in the 20s again.
As far as September being below normal.. we're at 13.3C as of the 22nd, or 1.0C above the normal monthly Sept mean of 12.3C. If the milder weather later this week materializes as forecast, there's a chance September could finish slightly above normal. I plugged in some numbers for the rest of the month based on current forecasts, and the month finished at 12.7C, about 0.4C above normal. So we still have a chance of keeping the above normal streak alive.
On the obs question....yes snowfall observations took a big hit with the automation. In Fargo for example, the official snowfall observer for Fargo climate is the cooperative observer who lives about 2 miles east in Moorhead MN. For Grand Forks, it is easier as NWS is now the official cooperative station instaed of UND and there actually are paid observers at GFK airport to supplement that place.
But these folks for GFK airport can only measure snow in a very confined area on the south side of the building. Thus in many winters their snow depth is quite low as the snow is blown away from their spot and their snowfall can be low as they go off what ASOS captures in the can which is often low due to wind.
So yeah snowfall climo at most sites were and still are messsed up.
Snow depth is always so hard I think. NWS is the official office for the city of Grand Forks with records back to the late 1800s. We do depths in an open field east of the office...and with wind we rarely get more than 7-8 inch depths in most winters...whereas in town with trees and such with less blowing depths are at least double. So which is correct....where we measure it is a snow depth of 7 but in the heart of the city anyone with a yard may have 15. But 7 is put down as the official depth in climate records. Should you incoporate drifts for snow depth measuring, or not??
Snowfall thankfully is a bit more scientific sometimes....except on those light snow days with lots of wind when nothing gets into the can and all the 3 inches is blown away to the next town. A guess-estimate is in order.
But the FAA and the automated sites were not designed for snowfall measuring and really rainfall either. These amounts dont impact whether a plane can fly in/out of an airport. FAA could care less about climate data... so NWS is foreced to use other sites to supplement with data that may or may not be as accurate as it once was.
Old record today is -6.1°C. Did we break it? This is just about as cold as it can get this time of year..ReplyDelete
This mornings temps over Winnipeg at 8am. Most all at freezing or below. Airport is coldest of course (rightfully so). See first image.ReplyDelete
This map doesn't include the CWB station, which is at 3.8C. See second image in above link. I assume theirs is mounted on the top of the CWB building somewhere, giving the warmer temps above the inversion.
Am I just an old fart? Re CoCoRaHS and snow and SWE - I was watching the obs in the US last winter and will be very interested to see if our volunteers can do a better job at measuring snow with their unshielded rain gauges.
A low of -6.5C at YWG airport this morning, so yes.. a record cold September morning out there. Coldest September temperature in Winnipeg since a -7.0C reading on Sep 28 2002. Even colder in Emerson at -8C and -9C at Dugald. Dry soils probably contributing to an accelerated heat loss.ReplyDelete
Looks like The Forks went slightly below zero too (?).ReplyDelete
-5.0 here in south end
A low of exactly 0.0C at the Forks.. which is early for them too (normal first 0C reading for them is Oct 5th)ReplyDelete
Amazing low temperatures this morning across southern MB for September.. including lows of -8.5C at Emerson and Fisher Branch. Only Alert and Isaachsen in the high Arctic were colder in Canada this morning at -11C.
+1 now at YWG. Didn't take long to warm up. (Westwood station at +10C!)ReplyDelete
I saw this time and again (mostly in winter) in my observing days in SK. Temps just after sunrise would plummet a degree or two in light to calm winds as the sun stirred up the cooler air sitting just below the thermistor level. A few minutes later it suddenly warmed up. The hourly METAR resolution doesn't do it justice.
The point here is that these new stations offer us better resolution into meteorological phenomena than the very sparse EC network can provide. Its much easier now to pick up on localized effects etc even if those stations are sub-standard w.r.t. to certain parameters. Remember.. we do not even have EC stations at Selkirk/ St Andrew's airport or Steinbach. Until such a time we do, this network is better than nothing.
Moving a station has to be accounted for when trying to analyze trends at a given location.. no matter how compliant it is with WMO standards.
was that hail or was it just snow pellets. I couldn't tell...was anybody in the south part of the city like in Windsor Park that experienced the same thing?ReplyDelete