Apex Weather

St. John Valley weather for Sept. 14-20, 2022

3-Day Outlook: Wednesday-Friday

A closed low along with a surface occluded front is moving through the Valley this Wednesday morning and will be followed by a surface cold front later today as the associated low pressure area lifts to the northeast in Canada. 

Winds will pick up this afternoon as a Canadian air mass builds in with gusty west winds later today and tonight. Showers this morning will taper off over the afternoon with partly cloudy skies developing overnight. Isolated showers are possible overnight as a disturbance circulating around the departing upper-low moves across the region.

Clouds will decrease Thursday with partly cloudy skies expected across the St. John Valley, along with gusty northwest winds. Skies become mostly clear Thursday night with gusty northwest winds continuing producing “feels like” temperatures in the mid-30s overnight. Gusty northwest winds continue Friday morning before subsiding in the afternoon. Mostly clear skies develop Friday afternoon and continue overnight as high pressure slides across the US Northeast.

NWS Caribou notes that Friday night will likely be “the coldest night so far this year with frost headlines possible across the North Woods west of Route 11. Strong radiational cooling with clear skies and light winds will result in lows in the upper 20s to low 30s in the valleys of the North Woods. The Saint John Valley east of Allagash looks to be spared from frost in the 36-39F range. East of Route 11 in the agricultural areas of Aroostook County expect lows in the upper 30s to around 40F.”

Wednesday, Sept. 14 

Cloudy with an 90 percent chance for showers, especially in the morning then a chance for showers in the afternoon. Between a quarter and a half-inch rainfall expected. High around 68 degrees. West wind 5-6 mph in the morning increasing to 10-15 mph and gusting 20-25 mph in the afternoon.

Wednesday night, partly cloudy and breezy with a 20 percent chance for showers. Low near 47 degrees. West-northwest wind 10-15 mph gusting 20-25 mph. 

Thursday, Sept. 15

Mostly cloudy in the morning with a slight chance for showers then partly cloudy in the afternoon. 20 percent chance for precipitation. Windy with a high around 58 degrees. Northwest wind 15-20 mph gusting 35-40 mph.

Thursday night, partly cloudy with a low near 42 degrees. Northwest wind 10-15 mph gusting to 25 mph. 

Friday, Sept. 16

Partly cloudy and breezy with a high around 59 degrees. Northwest wind 10-15 mph gusting to around 25 mph.

Friday night, mostly clear with a low near 38 degrees. Northwest wind 0-5 mph.

4 to 7 Day: Saturday – Tuesday

Model uncertainty increases Saturday as the high pressure ridge weakens and a frontal boundary looks to stall out over the Northeast. High pressure centered in the Gulf Saturday will keep mostly sunny skies across the Valley.  Partly cloudy skies are expected Sunday with a chance for isolated/scattered showers Sunday afternoon and Sunday night.

Scattered showers are expected Monday with partly sunny skies across the region. Mostly cloudy skies are expected Monday night into Tuesday morning with continuing chances for showers across the County. Partly sunny skies with a chance for showers continues Tuesday with the possibility of a low pressure system and associated fronts moving across the region.

Saturday, Sept. 17 (Constitution Day)

Mostly sunny with a high around 65 degrees. West wind 5-10 mph.

Saturday night, mostly clear in the evening then partly cloudy overnight with a 10 percent chance for showers. Low near 40 degrees. Northwest wind 0-5.

Sunday, Sept. 18

Partly cloudy with a 20 percent chance for afternoon showers. High around 64 degrees. Northwest wind 0-7 mph.

Sunday night, partly cloudy with a low near 41 degrees. 30 percent chance for showers. Northwest wind 0-5 mph.

Monday, Sept. 19

Partly sunny with a 30 percent chance for showers. High around 64 degrees. Southeast wind 0-5 mph.

Monday night, mostly cloudy with a 40 percent chance for showers. Low near 47 degrees. Southeast wind 0-5 mph.

Tuesday, Sept. 20

Mostly cloudy in the morning then partly sunny in the afternoon with a 40 percent chance for showers. High around 68 degrees. Southeast wind 0-7 mph.

Tuesday night, partly cloudy with a 30 percent chance for showers. Low near 50 degrees. South wind 0-5 mph.

8- to 14-Day Trends: Wednesday, Sept. 21-Monday, Sept. 26

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.

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