Many people are probably wondering what happened to the forecast of a nice weekend for southern MB (myself included). Just yesterday, the forecast was calling for sunshine all weekend and highs of 14 today and a balmy 19 on Sunday. Today, the weekend forecast dropped the high to only 11 today, and wait for it, a chilly +6 for Sunday (a 13 degree drop) with clouds and a chance of showers. Why the big flip? The simple answer.. poor model handling of a Hudson Bay vortex. Over the past few days, the model was indicating that the Hudson Bay vortex would stay to our north and just affect northern MB. However, based on the newest information, the model is now showing this vortex diving deeper into southern MB this weekend, sending that chilly airmass further south than earlier thought. The result.. instead of a nice sunny mild weekend, we will be turning cloudy and considerably cooler than had this airmass stayed to our north.
Note that all forecasts beyond Day 2 (tomorrow) are produced automatically from the model with no human intervention. Normally, this provides adequate accuracy for the Day 3-5 forecast. However, there are occasions when the model solution can change dramatically from one run to another, resulting in sudden and drastic changes to the forecast. This is particularly evident when the automated forecast is produced from a single model solution (in this case, using only the Canadian GLB model) A more promising forecast system, known as the ensemble forecast system, uses a blend of several model solutions to come up with a better forecast. Ensemble forecasts are generally more accurate (or at least, less wrong) and have less variability and "flip-flopping" It is hoped that EC will be moving to this new forecast system in the near future to produce more accurate long range forecasts and to help minimize those drastic forecast flips such as what we saw this weekend.
Don't look now.. but there's some flurries northwest of Winnipeg heading this way this morning! Hopefully the flurries die out by the time they reach us..
ReplyDeleteNope, they didn't die. :(
ReplyDeleteThey;re over SE Winnipeg right now too.
GO AWAY WINTER! :P
I washed my car last evening.. that sealed our fate. Can you believe this crap??!! So much for sunny and 19!!
ReplyDeleteThis is absolutely ridiculous! The snow is now coming down at a steady pace, and about 1 cm has accumulated on the grass and tree branches.
ReplyDeleteHopefully we get a warming trend come our way, and SOON.
WOW
ReplyDeleteIt's like a winter-wonderland out there!!
Oh boy!!!
SIGH.........
I agree with Rob and Jon, this is crappy and ridiculous! It is May and we are still seeing accumulating snow. Tomorrow's high is 15, but at this point I can hardly believe that is going to happen. I am hoping Brett Anderson from Accuweather is right when he says the second half of May will have above normal temperatures!
ReplyDeleteIn great hopes for some warmer weather, I decided to look at the 384 hr GFS run (even though its accuracy percentage out there is very very low). It shows temps upwards of 75F in about 10 days.
ReplyDeleteHopefully this somehow does at least hint at coming warmth.
Sorry, I meant 12-14 days.
ReplyDeleteAnother ridiculously cold night at Winnipeg airport. Even with clouds moving in ahead of this disturbance, it managed to reach an outlandish -9 C again. Most other CWB and EC sites were between -5 and -7. As stated previously, this drainage/damming effect is a real problem affecting climate data for Winnipeg.
ReplyDeleteIts amazing how compact the disturbance affecting us is. South of the cloud shield and precip it is 10 C in Hallock and 14 C in Melita. Hard to come with an accurate forecast with such a strong temp gradient.
Does anyone know what the average snowfall is for the month of May????
ReplyDeleteRemember how we saw less than average snowfall this winter?? Well this May we have the honour of getting ABOVE average snowfall! The average is 0.8cm in May, and by looking outside I probably have double, or even triple the average...WOW.
ReplyDeleteBy the way last year on this day it was 24 degrees. Today's minimum was 33 degrees colder than that, ouch!
ReplyDeleteI'm going to go out on a limb and say that I feel that tonight could be a record cold night for Winnipeg!!!
ReplyDeleteI mean with clearing skies and light winds the stage is set for a chilly night....
Maybe we have a very good shot...at record cold....at the airport that is!
Daniel.. yep, another chilly night but I don't think it will be a record breaker. Record low for tomorrow in Winnipeg is -8.3C (1968) For tonight, we pick up a light southeast wind overnight which will keep the airport from really bottoming out like the past 2 nights when we had a light northwest wind all night. The airport temperature will probably drop quickly this evening after sunset when the wind is still from the northwest, but then it should level off after midnight as the winds turn around into the south off the city. My guess.. low of -5C or so at the airport by midnight then staying steady or even rising overnight.
ReplyDeleteThe weekend weather we were supposed to have just arrived one day late. That's all.
ReplyDeleteBut that snow on Sunday got me depressed for a few hours until it melted again.
I still feel that we're headed for a 2004/2005-like Summer. Back then our Hi temps. were around +17 C