Tuesday, January 29, 2008

Here comes the cold!

Skies are clearing this morning across Winnipeg and the Red River Valley this morning as the storm system from last night sweeps eastward into Ontario. But don't let that sunshine today fool you.. it will do nothing to warm things up today. In fact, temperatures will be dropping through the day, with windchills of -45 or lower this afternoon. As of 10 am Brandon is at -30C with a -48 windchill, and that will be heading our way. Tonight, winds will ease off from today's gusty values, but temperatures in the minus 30s will combine with winds of 20-30 km/h to produce dangerous windchills in the -45 to -50 range. Look for these conditions to continue into Wednesday morning before winds drop off in the afternoon and evening. (Note that many school divisions cancel buses for windchills of -45 or lower.. this could be the case across Winnipeg and the Red River valley Wednesday morning.. so be prepared for alternate transportation for the kids tomorrow)

With clear skies and light winds, Wednesday night could see our coldest night of the winter so far with air temperatures dropping into the -35 to -40C range across southern MB, including Winnipeg. But if you think that's cold.. check out some of the temperatures this morning from central and northern Alberta (these are actual temperatures, not windchills).. -44C in Edmonton, -46C in Barrhead, and a reading of -49.5C at a climate station in Manning in far northwest AB. Now that is some serious cold!


  1. In the south-east of Manitoba most school divisions just out-right cancel classes if the temperature is -35 with a -45 wind chill. They are fairly strict with this, but if one value is at or above that temperature they will almost certainly cancel school.

  2. What a brutal day... the strong winds are keeping the low levels of the atmosphere well mixed not allowing temperatures to bottom out completely. The ridge axis doesn't move over us until midday tomorrow. Lets see how much this ridiculously cold airmass modifies as the late January sun beams down on an old, degraded snowpack. Saskatoon only could manage -32 C under the ridge axis this afternoon...we should be able to do better than that.

    Temperatures will quickly drop off with a light northwest flow at YWG early tomorrow nite. However a light south/southwest return flow should develop before dawn stabilizing temps there... coldest values will be on the southern and southwest fringes of the city. How low for Rob's Obs? ^.^

  3. How low will I go?? There's been 2 steady nights of -40 to -45 temperatures under the core of the Arctic ridge which passes over us tonight.

    The only difference is that we've managed to climb into the minus 20s here in southern MB compared to the -30s out west.. so that may prevent us from bottoming out as low as SK and AB did.. but we shall see.. The coldest I had last winter was -37C in February when the airport hit -41C.

    I'm thinking my site has a good shot at -35C tonight especially if I pick up that drainage wind from the south overnight.

  4. Here in Steinbach we hit -26 as a high, and -33 as a low. This is basically bang on to what EC said for today.

    Tonight will be interesting, looks like very cold wind chills of -45 to -50 for the south-east. EC has us at -49 in the morning, which is very likely, if not lower.

    School cancellations are another great possibility tomorrow.

  5. Minus 36 tonite at YWG just ain't gonna happen... flow already has switched to light southwest and temps are not not dropping dramatically. In addition, high clouds extending all the way back to Northern Alberta are on our doorstep... this will slow down radiative heat loss. Buoyant Pacific moisture is streaming over top of the extremely cold and dense dome of high pressure... this artic ridge is quickly getting 'dirtied up' and modifying significantly. Good thing too... could have gotten a lot colder here. Even areas subject to south drainage winds will not get too cold with those clouds moving in.

  6. Yeah.. I was down to -32 around midnight, then those clouds moved in and that was it. The airport was one of the "warmest" places last night with a light south flow off the city that kept the minimum temperature only at -30. I'm kind of surprised the temperature didn't drop more quickly last evening given the history of cold air in that ridge..

  7. The absence of a blocking ridge over the pacific seems to be key for us. Instead of having a northwest flow dumping the cold air thru Manitoba, a fast west/ southwest flow aloft allowed for the ridge to be whisked away and for pacific moisture to overspread it. Essentially the same ridge has now raced over Southern Quebec and New England where temps are only -5 to -10 C... hard to believe!

    Unfortunately part of the ridge has remained anchored in Yukon where it has not modified at all... it bares watching if the flow turns northwest and dumps that on our heads. Models are also hinting at an inverted trough coming up from a Colorado low on Monday... the volatile pattern continues!

  8. Yes, as you mentioned before Daniel, the La Nina pattern is in full force with strong upper ridging over the US southeast and troughing over the West Coast with an active storm track from the southwest US through the Great Lakes... just as climatology predicted months ago. Latest CPC monthly outlook indicates this pattern to continue through February with above normal temperatures over the US southeast (Florida will be a good getaway this winter) and below normal temperatures along the West Coast.

    In the short term, models show the storm track moving closer to us during the first week of February which will give us more variable weather and a better chance of some accumulating snow which has been noticeably absent this month (only 4 cm in Winnipeg - 4th lowest January snowfall ever) Temperatures however will likely average below normal as we stay on the cold side of the storm track, with only brief moderations as clipper systems periodically move through.