A powerful storm is slicing through the central portion of the US today on its way into Ontario after pounding the Rockies and plains with an intense blizzard. This storm was a beast, one of the strongest in years and certainly the most powerful this season. Along with heavy snow, strong thunderstorms and tornadoes, fierce winds occurred, in some cases gusting over 175km/h. Denver reported widespread blizzard conditions, with winds in excess of 125km/h. Thousands of flights were cancelled across the US, numerous highways closed and power out to over 200,000 residents across the region.
So what does this storm have to do with our weather here in Montreal? The broad circulation of the storm will push warm air across southern Ontario and Quebec over the next 48 hours. Temperatures will surge up to the warmest readings of the year so far, close to 10C (50F) on Friday. Accompanying the warm air will be gusty winds and some showers and perhaps even a thunderstorm in places. The warmth will begin to melt some of the deep snow and ice we have around the city. That, combined with any precipitation, will help to increase water levels on area rivers and lakes. This will likely result in the ice breaking up in many spots. It is time to stay off the ice and away from swift flowing water.
Some areas may also see flooding, caused specifically by snowmelt. While no weather warnings or advisories are in place at this time in southern Quebec, a flood watch has been posted for northern New York and Vermont. There is a concern for ice jam flooding along some smaller rivers and streams. The same conditions prompting that watch stateside, will exist here across the border in southern Quebec.
Cooler air will arrive this weekend behind a cold front, with a few flurries expected Saturday and daytime highs near 2C (36F). St. Patrick's Day Sunday will be sunny, but breezy and cooler, with a high of -3C (27F) for the parade in Montreal.