St. John Valley weather for Sept. 1-7, 2021
Short-Term Outlook: Wednesday – Friday
Partly sunny to mostly cloudy skies are expected over the Valley today as an upper trough to the northwest and moisture from Ida’s remnant low over the mid-Atlantic get drawn over the region. Dry air aloft will preclude precipitation other than a slight chance for an isolated shower today and tonight.
Ida’s remnant low tracks across the Gulf of Maine Thursday bringing mostly cloudy skies and increasing chances for rain by Thursday afternoon. Rain continues into Thursday night then taper to showers Friday morning as the upper-trough moves across the region and captures some of the low’s moisture in its circulation producing a chance for showers the Friday into Saturday morning.
For anyone needing to travel downstate, significant to heavy rainfall is possible late tonight into Friday morning, especially for Down East and east central portions of the region. Be alert for flood conditions in these areas.
For record keeping, Sept. 1 is the start of meteorological autumn, which lasts until Nov. 30. Astronomical autumn — the autumnal equinox — occurs at 3:21 p.m. ET on Sept. 22.
Today & Tonight / Beginning of Meteorological Autumn (Sept, October, November)
Partly sunny to mostly cloudy with a 5 percent chance for showers. High near 70 degrees with west-northwest winds 5-10 mph.
Tonight, partly cloudy in the evening then becoming mostly cloudy overnight with a 5 percent chance for showers. Low around 45 degrees with northwest winds near calm.
Thursday, Sept. 2
Mostly cloudy with a 40 percent chance for rain in the afternoon. Around 0.10-inch precipitation expected. High around 64 degrees with north winds 0-5 mph.
Thursday night, cloudy with a 50 percent chance for showers. Rainfall totals in the 0.10 to 0.25-inch range. Patchy fog possible overnight. Low near 50 degrees with north winds around 5 mph.
Friday, Sept. 3
Mostly cloudy with a 50 percent chance for showers. Rainfall totals in the 0.10 to 0.25-inch range. High around 57 degrees with north winds 10-15 mph.
Friday night, becoming partly cloudy with a 40 percent chance for showers. Low near 45 degrees with northwest winds 0-7 mph.
Medium-Range Outlook: Saturday – Tuesday
A ridge of high pressure over the Middle Atlantic brings partly cloudy skies and dry conditions Saturday. Partly sunny skies with increased chances for showers are expected Sunday as a cold front approaches from the west with a chance for widespread showers Monday as the cold front moves across the SJV. Another trough moves across the Valley Tuesday with a continued chance for showers across the region.
Saturday, Sept. 4
Partly sunny in the morning then becoming partly cloudy with a 20 percent chance for showers. High around 65 degrees with northwest winds 5-10 mph.
Saturday night, partly cloudy with a 10 percent chance for showers. Low near 42 degrees with west winds 0-5 mph.
Sunday, Sept. 5
Partly cloudy in the morning then becoming partly sunny with a 30 percent chance for showers. High around 70 degrees with south winds 0-5 mph.
Sunday night, mostly cloudy with a 60 percent chance for showers. Low near 53 degrees with south-southeast winds 0-5 mph.
Monday, Sept. 6
Partly sunny with a 50 percent chance for showers. High around 73 degrees with southeast winds 5-10 mph.
Monday night, partly cloudy with a 50 percent chance for showers. Low near 52 degrees with south-southeast winds 0-5 mph.
Tuesday, Sept. 7
Partly sunny with a 50 percent chance for showers. High around 72 degrees with southwest winds around 0-7 mph.
Tuesday night, partly cloudy with a 40 percent chance for showers. Low near 53 degrees with south-southwest winds 0-5 mph.
Long-Range Trends: Wednesday, Sept. 8-Tuesday, Sept. 14
Above normal temperatures / Above 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.