St. John Valley weather, May 10-16, 2023

3-Day Outlook: Wednesday, May 10-Friday, May 12

High pressure continues to build east from the Great Lakes today. A couple of disturbances circulating around an upper low north of Newfoundland will bring the chance for increased cloudiness this afternoon; however, no significant precipitation, if any, is anticipated. 

Otherwise, partly sunny skies are expected over the region once more. West/northwest winds will continue to be gusty in the 10-15 mph range with gusts to around 25 mph possible. Tonight, partly cloudy skies with near calm winds are expected with lows ranging from the middle 30s west to upper 30s east across the Crown of Maine. 

Thursday, sunny skies and dry conditions continue with lighter winds with highs reaching the lower 70s across northern Maine. Thursday night, partly cloudy skies with light winds are expected with increasing chances for showers overnight with lows dipping into the lower 40s.

A cold front moves through over the course of the day Friday with partly sunny skies and a chance for showers. There are some model differences on how much instability will occur Friday afternoon, and the amount of clouds/sun that the Valley receives will be one factor in determining whether any thunderstorms develop. Currently, the Storm Prediction Center has the entire state (in fact, the entire Northeast US) under a general thunderstorm threat for non-severe thunderstorms based on current data. 

The National Weather Service in Caribou indicates that the “best area of thunderstorms from Bangor to Greenville to Danforth in the Central Highlands.” Any thunderstorms that do develop will be driven by daytime heating and will end in the evening, though showers will remain likely overnight into Saturday. Rainfall totals are looking to be in the tenth- to quarter-inch range with higher totals possible in any thunderstorms. Daytime highs reach the lower 70s across the County with overnight lows in the middle 40s.

Daily Summary 

Today: Partly sunny. Highs in the lower 60s. West winds 10 to 15 mph with gusts up to 25 mph.

Tonight: Partly cloudy in the evening, then clearing. Lows in the upper 30s. West winds 5 to 10 mph.

Thursday: Sunny. Highs in the upper 60s. Northwest winds 5 to 10 mph with gusts up to 20 mph.

Thursday Night: Mostly clear. A slight chance of showers after midnight. Lows in the lower 40s. Northwest winds around 5 mph with gusts up to 15 mph, becoming south after midnight. Chance of rain 20 percent.

Friday: Mostly cloudy. A chance of showers in the morning, then showers likely with a chance of thunderstorms in the afternoon. Highs in the lower 70s. Southwest winds 5 to 10 mph with gusts up to 20 mph. Chance of rain 70 percent.

Friday Night: Mostly cloudy with showers likely with a chance of thunderstorms in the evening, then partly cloudy with a chance of showers after midnight. Lows in the mid-40s. Chance of rain 70 percent.

4- to 7-day Outlook: Saturday, May 13-Tuesday, May 16

High pressure builds down from the western Hudson Bay region and across James Bay over the weekend. Saturday will be partly sunny and cooler with a chance for showers and breezy northwest winds. Partly cloudy skies overspread the Valley Saturday night with showers becoming isolated overnight before ending early Sunday. Sunday is expected to be partly cloudy and breezy, and Sunday night features partly cloudy skies and dry conditions. 

Monday continues to be partly cloudy with a chance for afternoon showers as a cold front approaches from the northwest. Skies become mostly cloudy Monday night with a chance for showers followed by partly sunny skies Tuesday with a continuing chance for showers. Tuesday night looks to be partly cloudy with a chance for showers.

Daily Summary

Saturday: Partly sunny. A chance of showers in the morning. Highs in the upper 50s. Chance of rain 40 percent.

Saturday Night: Mostly clear. Cold with lows in the mid-30s.

Sunday: Partly sunny. Highs in the upper 50s.

Sunday Night: Mostly clear. Lows in the upper 30s.

Monday: Partly sunny. Highs in the lower 60s.

Monday Night: Partly cloudy with a 30 percent chance of showers. Lows around 40.

Tuesday: Partly sunny. A chance of showers in the afternoon. Highs in the lower 60s. Chance of rain 30 percent.

Tuesday Night: Partly cloudy. A chance for showers. Lows in the lower 40s. Chance of rain 30 percent.

8- to 14-day Trends: Wednesday, May 17-Tuesday, May 23

Near 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.