Monday, January 26, 2009
Temperatures rising this week.. but so are the winds
After several days in the minus 20s, temperatures will be moderating this week into the minus teens for Tuesday, and the minus single digits by Friday. Unfortunately the milder weather will be accompanied by strong southerly winds at times which will make the warmup less noticeable. This will be especially true Tuesday as brisk southwest winds of 30 km/h in the morning increase to southerly winds of 40 to 60 km/h by evening in the Red River valley, making those -14C high temperatures feel more like -25 to -30. We cool off a bit for mid week (but with lighter winds) then a storm system crossing through the northern Prairies on Friday will bring a westerly flow of milder air into southern MB, with temperatures likely climbing into the minus single digits for the last day of January. Other than some light snow Wednesday (2 cm or less), little or no snow is expected through the upcoming week.
Posted by rob at 7:15 AM
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Those gusty southerly winds to 50 and 60 km/h this evening doing little to raise our temperature. Still sitting at -20C in the Red River valley this evening, when we were supposed to be up to -15C or so. We'll likely rise overnight as those clouds move in and we lose this pesky valley wind. Wednesday will be a lot nicer than today with lighter winds, and temperatures near -10C.ReplyDelete
40 % chance of rain showers on Saturday...have not heard rain showers in the forecast for quite some time!ReplyDelete
Has anyone seen the pictures of the major ice storm down south~????
I'm not so sure about those rain showers.. it's purely a model driven forecast that is looking at that high of plus 1 and thinking rain.. but it's unlikely given the setup.ReplyDelete
Speaking of windy.. look at Pincher Creek this evening.. 90 km/h sustained gusting 110 km/h!
Here is a link to some photos from WFO Paducah Kentucky. My hometown is in western Kentucky as well...but couldnt stand the warm winters down there. But I am sure they will post many more pictures.
Concerning the rain showers on Saturday....I talked with a lead forecaster at PASPC a while back and any forecast beyond 24 hrs is strictly from the models and they are not allowed to alter any wording. So like Rob said strictly model driven. It does look pretty mild though...I hate the slop weather....much rather it stay way below zero.
So much for the 40% chance of showers and +1C for Saturday.. Now it's cloudy and -10C! Ahh, the fickleness of model forecasts!ReplyDelete
In the case for Saturday, yesterday's GLB model run had a low tracking through the Interlake drawing mild air into southern MB, getting us above the freezing mark (well, in model land anyways). Last night's run has taken this low a little further south, along with the attendant warm sector. That being said, the high of -10C looks too cold now. Ensemble forecasts would suggest a high of -3 to -5C for Saturday as a more reasonable first guess.
The WRF (my signature model) is showing a high of around zero for most of southern Manitoba on Saturday. Usually the WRF is quite accurate with high temperatures, and adapts to potential changes quickly. Since this is still 72 to 84 hours away anything could happen, but right now I think zero is still possible.ReplyDelete
Now it's back to 3 C with periods of rain or snow on Saturday!ReplyDelete
Like talk about model flop!
I think that 3 degrees is a little too optimistic for Saturday. I personally think that temperatures barely reaching zero would be most likely.ReplyDelete
+1, -10, +3.. you get the idea that the GLB model is having a bit of difficulty deciding how this next clipper will track. This is the problem with having an automated forecast based on one model.. you can get these significant flip flops from one model run to the next. That's why going with a model ensemble approach is far superior for long range forecasts.. you reduce the flip flop factor, and generally you get better forecasts that trend towards reality.ReplyDelete
As for this Saturday.. model consensus has the low tracking through the southern Interlake region, putting southern MB into a brief warm sector during the day. This clipper will bring an area of snow through the Interlake (5-10 cm?), with little or no pcpn over the south. Temperatures will likely be rising to near freezing over southern MB Saturday including Winnipeg, with highs ranging from -5 north of Winnipeg to 0C near the US border.
Forecast highs for Saturday in Winnipeg from various sources..ReplyDelete
CBC Winnipeg..... -3C
CTV Winnipeg..... -3C
Weather Network.. 0C
As you can see, EC's forecast of +3C is an outlier..
Well Environment Canada just went for a warmer temperature on Saturday with a high of 4 C with rain showersReplyDelete
There must be a reason why that model is showing it that warm!
That high of +4C is still an automated forecast from the GLB model. We'll see what tomorrow morning's forecast says when it's based on UMOS data from the regional GEM. I suspect it will be a few degrees cooler..ReplyDelete
The setup is there for a brief warmup into plus temperatures over southern MB Saturday. Most of Alberta and southern SK will be seeing above freezing highs on Friday, and we'll be tapping some of that air on Saturday with a westerly flow as the warm air occludes out. Sometimes the westerly flow is enough to get us briefly above freezing before the cooler air moves in.
This is one of the reasons that weather services get such a bad rap...I can already hear people complaining about where that +4 weather went!ReplyDelete
I agree with Rob and still think a high of around 0 is the best. The WRF has been fairly consistent over the last while with highs between 2 and -3 over southern Manitoba. As much as I would like +4, I just can't see it happening. If we do indeed get to 0, we can still claim a January thaw (Jan. 31)!