Tuesday, January 13, 2009

Record cold morning over southern MB

An Arctic ridge of high pressure brought clear skies and light winds over southern MB last night producing some very cold temperatures early this morning. Morning lows were in the minus 35 to minus 40C range in most localities, with Sprague in extreme SE Manitoba registering an exceptional -43.8C! Other spots hitting -40C this morning included Bird's Hill (-40.5C), Piney (-42.5C) and Indian Bay (near Falcon Lake) at -41.0C.

Officially, at least 6 record lows were set this morning over southern MB including:

(old record in brackets)

Sprague.. -43.8C (-41.1 1979)
Pinawa... -39.4C (-38.3 1979)
Gimli.... -39.3C (-37.2 1972)
Gretna... -37.8C (-34.8 1999)
Fischer Branch.. -38.3 (-37.0 1988)
Pilot Mound.. -35.3C (-34.3 1972)

Winnipeg Airport got down to -37.6C, shy of the record low of -40.0C on this date in 1881.

Another cold night is expected tonight, however winds will be more of an issue overnight through Wednesday as another Arctic ridge pushes in from the north. North winds of 20-30 km/h will produce wind chills in the -40 to -45C range across southern MB Wednesday.


  1. Extreme morning lows in RRV basin all the way down into Fargo, SE Manitoba and NW Minnesota under the ridge. Grand Forks shattered their record of -35 C also from 1979 by hitting approx -38.5 C and Fosston MN dropped below -40 C.

    The cold dense air deflected the next clipper SW from what models were progging. The cloud line only brushed Winnipeg today ahead of the next arctic high building south. Column remains very cold with 850 MB temps the same but northerly flow should keep things better mixed tonite.

    The second arctic ridge will set up further west over Saskatchewan and central ND as previously mentioned. We should stay in a bit of gradient Wednesday nite as well. If model verifies then a weaker inverion would set up giving slightly warmer lows Thursday morning.

  2. I think tonight might be colder than any of us are anticipating. Winnipeg is already -32C at 5:00 p.m. The city is expected to be under a north-west flow by early morning...need I explain further. The wind should keep temperatures slightly warmer in theory, as Daniel mentioned. However I never wish to doubt what a north-west flow could do to YWG.

    Once the RUC goes all the way to 12Z I should be able to predict a low for Winnipeg.

  3. Surprise! ...YWG jumps back up 3 degrees to -29 C. Getting more of a NE fetch now. Most of the CWB open country sites siting at -30 to -31 C now.

    Winds are too light and arctic inversion quickly is re-establishing itself (we never really broke it during the day as we stayed in the clear, calm air). Models hinting at a tightening gradient off the surface (925 MB) by around 3 AM. However with aforementioned inversion setting up and winds de-coupling... surface winds may stay below 10 kmh.

    If that is the case don't be surprised to see a repeat of this mornings overnite lows. -38 C outside the city -30 in the downtown core. Colder values in the usual areas.

    YWG... Impossible to predict exactly how cold air drainage pattern will evolve any given nite. As evidenced by last nite.. the temperature fluctuates chaotically in response to mixing and drainage. Low was reached as temperature suddenly plunged nearly 5 C after stabilizing at -33 C for several hours.

    Having said all that with light NE flow backing to WNW.. a quick spike down to -37 C wouldn't surprise me at YWG.

  4. -34 C at the Winnipeg airport as of 10:00 pm
    With this light NW flow the city is gonna get very cold tonight!

  5. Daniel is right...Tonight's low temperatures will be bouncing around all over the place.

    The RUC shows the main push of cold air after midnight, at which time the temperature will drop steadily downward...until then the temperature will probably keep bouncing.