(North Bay March 31, 2023) A Colorado low pressure system is moving through the province today and tomorrow, bringing snow, freezing rain, ice pellets, and rain to the North Bay – Mattawa region. Accumulations of up to 15 cm of snow and 15 mm of rain are expected between this evening and throughout Saturday, prompting the North Bay-Mattawa Conservation Authority to issue a Watershed Conditions Statement – Flood Outlook.
“Significant snowpack remains across the North Bay – Mattawa region and lakes are frozen. Water levels and flows across much of the North Bay – Mattawa region are normal for this time of year. Warmer weather and rainfall will see rivers and streams respond accordingly. Snowmelt and rainfall expected over today and tomorrow could result in potential flooding in low lying areas with a history of flooding,” said Angela Mills, NBMCA Duty Officer.
Daytime temperatures from now into early next week will hover around the freezing mark with nighttime temperatures remaining close to freezing Friday (March 31st) night, and around -15 °C Saturday (April 1st) night. The seven-day weather forecast indicates temperatures above 0 °C for the early part of next week, with a possible high of 8 °C and ~ 10 mm of rain. This could result in snow melt in addition to the forecasted rain.
North Bay-Mattawa Conservation Authority (NBMCA) conducted a snow survey today (March 31st). Snow depths range between 49 and 52 cm in the NBMCA watersheds. Snow water equivalence ranges between 169 mm in the Kaibuskong River subwatershed, 175 mm in the La Vase River subwatershed, and 184 mm in the Chippewa Creek subwatershed. This averages to 214 % of normal, based on more than 15 years of data.
Localized flooding from area watercourses is possible if substantial rainfall and snowmelt occurs. Water is likely to accumulate on roadways, parking lots and flat or low-lying areas but serious flooding is not anticipated at this time.
The low temperature tonight will remain above zero around 1 ºC, with a high temperature tomorrow of 6 ºC causing further snowmelt before returning below zero with a low of -1 ºC tomorrow night. Weekend highs remain around 6 ºC and lows cooling to around -5 ºC overnight. Warmer temperatures are possible Monday.
Significant snowpack remains across the North Bay – Mattawa region and lakes are frozen. Water levels and flows across much of the North Bay – Mattawa region are normal for this time of year. Warmer weather and rainfall will see rivers and streams respond accordingly. Snowmelt and rainfall expected over today and tomorrow could result in potential flooding in low lying areas with a history of flooding.
Residents, especially those in low lying areas, are encouraged to monitor the conditions as they develop, and prepare accordingly. Shorelines of creeks and rivers will be very slippery at this time and when combined with cold open water, pose a serious hazard. Parents are encouraged to keep their children and pets away from watercourses and off water bodies that have unstable ice conditions.
Municipalities are encouraged to monitor water crossings to ensure the continual movement of water through culverts and bridges. A close watch on local conditions and updated forecasts and warnings from Environment Canada is also recommended.
Staff at the North Bay-Mattawa Conservation Authority will continue to monitor weather and watershed conditions and update this message based on the changing weather/streamflow conditions.
The general public is advised of these messages through the www.nbmca.ca website with the flood status icon and a link to information about current conditions. NBMCA also circulates these messages to local media and social media, posting on Twitter @theNBMCA, Instagram nbmcainfo, and Facebook theNBMCA.
This message will be in effect until (or updated before) Thursday, April 6, 2023 at 12:00 pm.