Wednesday-Friday
Today, hot and humid conditions continue with a heat advisory in effect until 8 pm. However, the high pressure ridge begins to break down as an upper trough and surface cold front approach bringing a chance of isolated to scattered afternoon/evening showers/thunderstorms to the Valley. A few storms may have the potential to produce gusty winds and heavy downpours.
Additionally, the Weather Predication Center has portions of northern Maine — including much of the Saint John Valley along with the North Woods/Allagash — at marginal risk for excessive rainfall with localized flash flooding due to rapid runoff possible.
Showers are likely this evening along with a chance of evening thunderstorms as the cold front approaches and moves through overnight into early Thursday. A chance of showers continues overnight into Thursday. Highs today reach the lower 90s with overnight temperatures in the middle 60s.
The upper-level trough and cold front cross the Valley Thursday with a chance of showers into the afternoon. Clouds diminish later Thursday with daytime highs topping out in the middle 70s. Mostly clear skies are expected overnight into Friday with lows in the mid-40s.
High pressure tracks from Québec across the SJV Friday with clear skies and much drier, cooler air moving into the region. Highs in the upper 70s and lows in the mid-40s are expected.
Saturday-Tuesday
High pressure moves into the Atlantic southeast of Maine Saturday with mostly sunny skies continuing with southerly flow bringing some warmer temperatures with highs in the lower 80s. A cold front approaches later Saturday with a slight chance of showers after midnight and partly cloudy skies. Lows in the upper 50s are expected.
The cold front moves through Sunday with a chance of showers along with some afternoon thunderstorms possible. Highs in the middle 70s are expected. Sunday night, partly cloudy skies with a chance of showers and lows in the upper 40s.
A new ridge of high pressure centered near the Great Lakes builds into the region through midweek with mostly clear skies, mild, and dry conditions. Highs in the upper 60s Monday and low 70s Tuesday with lows in the lower 40s Monday night and mid-40s Tuesday night.
Daily Forecast
Wednesday: Sunny. Scattered showers and thunderstorms this afternoon. Locally heavy rainfall possible this afternoon. Hot with highs around 90. Southwest winds 5 to 10 mph. Chance of rain 40 percent.
Wednesday Night: Mostly cloudy. Numerous showers and scattered thunderstorms in the evening, then scattered showers with isolated thunderstorms after midnight. Patchy fog after midnight. Locally heavy rainfall possible in the evening. Humid with lows in the lower 60s. Southwest winds around 5 mph. Chance of rain 60 percent.
Thursday: Partly sunny with a 50 percent chance of showers. Not as warm with highs in the mid-70s. Northwest winds 5 to 10 mph.
Thursday Night: Mostly clear. Much cooler with lows in the mid-40s. North winds around 5 mph.
Friday: Sunny. Highs in the lower 70s. North winds around 5 mph.
Friday Night: Mostly clear. Lows in the lower 40s.
Saturday: Sunny. Highs in the lower 80s.
Saturday Night: Partly cloudy in the evening, then mostly cloudy with a chance of showers after midnight. Not as cool with lows in the upper 50s. Chance of rain 50 percent.
Sunday: Showers likely. Highs in the mid-70s. Temperature falling into the upper 60s in the afternoon. Chance of rain 70 percent.
Sunday Night: Mostly cloudy with a chance of showers in the evening, then partly cloudy after midnight. Cooler with lows in the mid-40s. Chance of rain 50 percent.
Monday: Mostly sunny. Highs in the mid-60s.
Monday Night: Mostly clear. Lows in the lower 40s.
Tuesday: Sunny. Highs in the upper 60s.
Tuesday Night: Mostly clear. Lows in the lower 40s.
Note: Computer model precision diminishes as the week progresses. Check The County.me or the National Weather Service Caribou, ME at for weather updates with more current information for the Saint John Valley.
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.
