St. John Valley weather for May 26 to June 1, 2021
Short-Term Outlook: Wednesday – Friday
Low pressure tracking from James Bay in Canada towards the Gulf of Saint Lawrence will draw a cold front towards the region tonight.
This afternoon, a prefrontal trough preceding the cold front will move through the Valley. With dew points in the 60s and precipitable water in the atmosphere at or greater than 1.5 inches along with favorable wind shear conditions aloft, isolated strong to severe thunderstorms are possible across the SJV this afternoon into the evening hours. The major concern will be damaging wind gusts from stronger cells and the slight chance of a tornado cannot be entirely ruled out.
Based on high-resolution forecast models, most of the storms will move east of the region by the mid-evening period with lingering showers through the overnight period as the main cold front moves through after midnight. Behind the cold front, skies will clear and northwest winds will pick up as incoming high pressure over Manitoba and the departing low pressure create a pressure gradient across the SJV.
High pressure will dominate the Valley’s weather Thursday and Friday with cooler, drier air. Temperatures will fall into the 30s in Fort Kent and vicinity Thursday and Friday nights, and frost may be possible depending on wind speeds. Needless-to-say, those with agricultural interests or temperatures sensitive vegetation should monitor the conditions both nights.
Today & Tonight
Increasing clouds in the morning then becoming cloudy in the afternoon with an 80 percent chance for showers, especially in the afternoon, along with a chance for afternoon thunderstorms. Isolated strong to severe storms with damaging storm winds possible. Rainfall totals near 1/4-inch with higher totals possible in thunderstorms. High around 83 degrees with southwest winds 10 to 15 mph.
Wednesday night, cloudy in the evening then becoming partly cloudy with an 80 percent chance for showers and a chance for thunderstorms in the evening. Rainfall totals around 1/10-inch. Low around 43 degrees with northwest winds 10-15 mph.
Thursday, May 27
Mostly sunny with a 5 percent chance for showers, mainly in the morning. High near 53 degrees with northwest winds 10 to 15 mph.
Thursday night, mostly clear with a low around 34 degrees. Northwest winds 5 to 10 mph.
Friday, May 28
Mostly sunny with a high around 55 degrees. Northwest winds 10 to 15 mph dropping to 5 to 10 mph in the afternoon.
Friday night, mostly clear with a low around 33 degrees. Some frost possible, particularly in the North Woods and sheltered locations. Northwest winds near 5 mph.
Medium-Range Outlook: Saturday – Tuesday
High pressure in Canada will build across the Valley for the Memorial Day weekend. An area of low pressure tracking from the Midwest will be suppressed to the south by the ridge of high pressure and track well offshore to the south Saturday and Saturday night, though a few clouds might make their way to the region.
Surface high pressure is expected to move into the eastern Canadian Maritimes by Sunday with an approaching upper trough moving towards the region from the west. Clouds are expected to increase Monday and Tuesday along with chances for isolated shower activity.
However, variations in computer models regarding the track of an offshore low Monday into Tuesday leave a degree of uncertainty in the Valley’s weather conditions for early next week.
Saturday, May 29
Mostly sunny with a high around 60 degrees. 5 percent chance for showers. North-northwest winds 5 to 10 mph.
Saturday night, mostly clear with a low around 35 degrees. 5 percent chance for precipitation. North-northeast winds 0 to 5 mph.
Sunday, May 30
Mostly sunny in the morning then becoming partly cloudy in the afternoon with a high around 65 degrees. 10 percent chance for isolated afternoon showers. Northeast winds 5 to 10 mph.
Sunday night, partly cloudy with a low near 40 degrees. 10 percent chance for isolated showers. Northeast 0 to 5 mph.
Monday, May 31 / Memorial Day
Partly cloudy with a 10 percent chance for isolated showers. High around 65 degrees with northwest winds 5 to 10.
Monday night, partly cloudy with a 20 percent chance for isolated showers. Low around 45 degrees with south-southwest winds 0 to 5 mph.
Tuesday, June 1
Partly sunny with a 30 percent chance for scattered showers, mainly in the afternoon. High near 71 degrees with west winds 5 to 10 mph.
Tuesday night, partly cloudy with a 20 percent chance for isolated showers. Low near 49 degrees with west-southwest winds 0 to 5 mph.
Long-Range Trends: Wed. June 2 – Tue. June 8
Above normal temperatures / Below normal precipitation
Note: Computer model precision diminishes the further into the week the forecast projects. Check the Fiddlehead Focus for weather updates with more current information.
The Week Ahead is the work of UMFK Professor Joseph E. Becker based on personal weather station data, various computer forecast models, and information that the National Weather Service, NOAA, and other weather resources provide.