Monthly Archives: December 2015

Winter 2015/16 Forecast. Elnino’s Hiatus

Even the one of the strongest El Nino on record needs to connect with the Atmosphere(coupling) to have it’s full effects felt. Mid winter may see El Nino’s effect dampened. looking back I found this was somewhat the case during the Super Elnino of 1982/83.

While one might argue about the below normal snowfall remember, this was the case last winter as well when we had neutral or weak El Nino conditions.

The PNA pattern seems to stray from what is expected so this forecast is factoring that in. It’s duration seems to be until around mid January

Forecast is made using multiple sources over a timeframe. no single or proprietary source.

Overall Winter 2015/16 should see near to Above normal temperatures with the exception of the Northwest(slightly below) and near(in the mountains) to below Snowfall. Well below in south-eastern Alberta.

December: Near to slightly above normal overall and dry.

After the mild first half; the 2nd half of December will be generally colder than normal with lows down to -35C a few times over most of the province. This will cancel some or all of the positive temperature anomalies seen during the first two weeks.

January: Near normal to slightly Above. Dry

Generally cold with a few Chinooks in the south west parts. Chance of milder conditions towards the end of the Month

February:Near normal to warmer than normal. remaining dry.

Becoming very mild late in the month, possibly melting most of the snow by the begining of march. Cold early on may linger

 

Sneak peak(not to be seen as a seasonal forecast):  CFSv2 seems to point toward more significant warm anomalies in March, April, and May.  It’s a very long way out but something to watch for. If it remains by the time of the Spring 2016 forecast; it may indicate an early and intense kick-off to the fire season.

 

 

December 2015 Forecast: In the heart of El Niño

With A beast of an El Nino pattern starting to really effect the jet stream and makes forecasting quite easy. It is one of the heaviest factors in forecasting. The other factor that can effect winter weather is the Arctic Oscillation which is currently in the positive phase. This strengthens the Jet even more locking the cold air in the Arctic.

Currently the warm and dry bias is very high and aside from a single 3 or 4  day cold snap the month of December should be above to well above normal and dry to very dry. Anomalies are likely to finish off in the +3-8C range in a wide swath of central Alberta and southern Alberta. The extreme north should also get a good 2C warmer than normal.

Snowfall is expected to be very low, Cities like Edmonton may struggle to maintain snow cover while Calgary could spend most of the winter without any snow cover. Regions that received more than 8″(20cm) during the November storm have the best chance to maintain snow cover into the new year. Mild and dry winters actually lead to more winter kill of perannuals and winter crops due to a lack of snow cover and false germanation. Winter nights are long and can still get very cold, even if the daytime gets well above freezing.

Anomaly Maps for December

December in detail:

Dec 1-10: Very mild, little or no snow to speak of. More likely to see more freezing rain in the north.

Dec 10-20: Remaining very mild, turning colder.

Dec 20-31: Possible snowstorm around Christmas followed by a 3 or 4 day cold snap. Becoming very mild once again toward the new year. 2016