St. John Valley weather for Aug. 25-31, 2021
Short-Term Outlook: Wednesday – Friday
Partly cloudy skies will overspread the Valley today as high pressure builds across the region. Chances for showers increase after midnight tonight as a cold front approaches from the west-northwest.
A prefrontal boundary will trigger a chance for showers early Thursday followed by showers and scattered thunderstorms as the main cold front moves through. Based on current model data, some isolated strong to severe storms are possible with locally heavy rainfall and gusty winds. Partly cloudy skies develop Thursday night as a large ridge of high pressure builds down from the James Bay region in Canada bringing a notably drier and less humid air mass into the Saint John Valley Friday.
Today & Tonight
Mostly sunny with a 10 percent chance for isolated showers. High near 86 degrees with west winds 0-7 mph.
Tonight, partly cloudy with a 40 percent chance for showers after midnight. Less than 0.10-inch rainfall expected. Patchy fog possible overnight. Low near 64 degrees with south winds 0-5 mph.
Thursday, August 26
Partly cloudy to partly sunny with a chance for showers in the morning then showers likely with a chance for thunderstorms in the afternoon. Chance for precipitation 60 percent. Rainfall totals less than 0.10-inch expected with higher amounts possible in storms. High near 86 degrees with southwest winds 5-10 mph.
Thursday night, partly cloudy with a 40 percent chance for scattered showers and thunderstorms in the evening. Rainfall totals less than 0.10-inch expected. Low near 55 degrees with west to northwest winds 0-7 mph.
Friday, August 27
Partly cloudy with a 5 percent chance for showers. High near 68 degrees with northwest winds 10-15 mph gusting to 20-25 mph.
Friday night, mostly clear with a low near 45 degrees. Northwest winds 0-7 mph.
Medium-Range Outlook: Saturday – Tuesday
High pressure will build down from the James Bay region Friday with a cooler, less humid air mass building into the area. High pressure will remain across the region Saturday then move east Sunday. Isolated showers are possible Sunday evening as a warm front lifts towards the region with showers possible Sunday night and Monday as a cold front remains to our west. The cold front moves through Monday into Tuesday with afternoon showers and thunderstorms possible. Clouds decrease Tuesday behind the front with a chance for scattered shower activity.
Saturday, August 28
Partly cloudy with a 5 percent chance for showers. High near 72 degrees with north winds 0-7 mph.
Saturday night, partly cloudy with a 5 percent chance for showers. Low near 46 degrees with northwest winds 0-7 mph.
Sunday, August 29
Partly cloudy with a 20 percent chance for isolated afternoon showers. High near 75 degrees with south winds 0-7 mph.
Sunday night, partly cloudy with a 50 percent chance for showers. Low near 55 degrees with south winds 0-7 mph.
Monday, August 30
Mostly cloudy with a 60 percent chance for showers and afternoon thunderstorms. High near 74 degrees with south winds 8-14 mph.
Monday night, partly cloudy with a 50 percent chance for showers. Low near 59 degrees with southwest winds 0-7 mph.
Tuesday, August 31
Partly sunny in the morning then partly cloudy in the afternoon with a 30 percent chance for showers. High near 78 degrees with west winds 0-7 mph.
Tuesday night, partly cloudy with a 10 percent chance for showers. Low around 55 degrees with northwest winds 0-7 mph.
Long-Range Trends: Wed. Sep. 1 – Tue. Sep. 7
Above normal temperatures / Near 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.