|Winnipeg forecast shows change to much colder weather by next weekend|
|850 mb temperature plot valid next Monday Jan 11th|
from ECMWF shows large Arctic outbreak over Prairies
Temperatures this week will be mainly in the minus single digits with no significant precipitation expected through Thursday. On Friday, a storm system passing through the Dakotas will spread an area of snow across southern Manitoba, with a general 2-5 cm possible. Winds will shift into the north behind this system, heralding the arrival of much colder air for the weekend into early next week. Look for daytime temperatures in the minus 20s and nighttime lows in the minus 30s as the coldest airmass of the season pushes into the Prairies.
So once that cold air gets here, how long will it last? The coldest core of the airmass looks like it will be coming through Sunday through Tuesday before a slight moderation next week. After that, it's tough to say how January will end up, however given past previous strong El Nino episodes, the odds favour a milder than normal January over southern MB. Of the past 6 strong El Ninos since 1950, five Januarys were milder than normal here, including during the record strong El Ninos of 1997-98 and 1982-83. (see composite map below) Note that cooler than normal weather is more likely over the southern US due to a strong southern jet stream bringing more frequent storm systems and precipitation from California through Texas to the US southeast.
JANUARY TEMPERATURE ANOMALIES DURING STRONG EL NINOS
|Composite map showing average temperature anomalies in January|
based on average of past 6 strong El Ninos since 1950