Apex Wx

Overview: The slow-moving nor’easter centered near the New Jersey and New York coast Sunday morning will remain the dominant regional weather feature into Monday, while strong high pressure over Quebec continues to resist the low's northward advance. Dry continental air should keep the Upper Saint John Valley near the northern edge of the storm’s meaningful moisture through much of Sunday, allowing mainly dry conditions despite increasing clouds as the day progresses. Temperatures should remain unusually mild, reaching the upper 60s to around 70°F.

The blocking pattern begins to relax Sunday night as the Canadian high shifts east and the coastal low lifts toward southern New England and eventually the Gulf of Maine. Atlantic moisture should finally spread farther into northern Aroostook County, with rain becoming increasingly likely Monday, mainly in the afternoon, and continuing into Monday night. Rainfall totals across the County should remain considerably lighter than farther south in the state, with 0.10 to 0.25 inch possible in Fort Kent and other Valley communities.

The weakening system accelerates northeast toward Nova Scotia Tuesday. Lingering rain or showers should gradually diminish during the morning, although clouds may remain stubborn into the afternoon. Winds also ease as the storm pulls away, with progressively drier and quieter weather returning to the Valley later Tuesday.

Sunday: Fort Kent and the Upper Valley should remain largely north of the rain through the daytime hours, with considerable high and mid-level cloudiness but some filtered sunshine possible. Temperatures should still reach the upper 60s to around 70°F, with northeast winds generally light to moderate. Clouds thicken tonight as moisture advances northward, and rain chances increase toward Monday morning. Lows should fall into the upper 30s to lower 40s.

Monday: The coastal system finally makes its more noticeable push into northern Maine. Clouds will dominate, with rain becoming increasingly likely as the day progresses and continuing into Monday night. The clouds and precipitation will hold temperatures to around the upper 50s to lower 60s, noticeably cooler than Sunday. Northeast winds remain somewhat noticeable but gradually ease. Monday night stays cloudy and damp, with lows in the upper 40s.

Tuesday: Lingering rain or showers are most likely during the morning as the weakening system moves northeast toward Nova Scotia. Precipitation should gradually diminish, although considerable cloud cover may persist into the afternoon. Highs should remain around the upper 50s to near 60°F. Tuesday night turns quieter and cooler as drier air begins returning to the Valley, with lows generally in the upper 30s to lower 40s.

Wednesday, September 30 – Saturday, October 3

Overview: The nor’easter affecting Maine early in the week should be well east of the region by Wednesday, allowing weak high pressure and upper-level ridging to bring drier and increasingly mild weather back to northern Maine. Lingering low-level moisture may produce some clouds Wednesday morning, but improving sunshine should help temperatures rebound into the upper 60s to around 70°F.

The ridge remains influential Thursday as mild southwest flow develops ahead of the next disturbance. This should produce the warmest day of the period, with temperatures reaching the lower 70s across the Upper Saint John Valley. Mainly dry conditions are favored through Thursday, although clouds should begin increasing as the next system approaches from the west.

A cold front crosses the region late Thursday into Friday. Moisture appears limited, so scattered showers are possible but widespread or significant rainfall is not expected. The more noticeable change arrives behind the front Friday night as winds turn northwesterly and a much cooler, drier Canadian air mass spreads into Aroostook County. High pressure begins rebuilding Saturday, favoring mainly dry weather and some sunshine, but daytime temperatures should remain only in the mid- to upper 50s.

Wednesday: The Valley transitions fully away from the early-week coastal system, with lingering clouds giving way to increasing sunshine. A much milder afternoon is expected, with highs in the upper 60s to around 70°F and generally light winds. Clouds become more numerous again Wednesday night, with lows in the upper 40s to near 50°F.

Thursday: This should be the warmest day of the period as sunshine and mild southwest flow allow temperatures to reach the lower 70s. Conditions remain mainly dry through the day. Thursday night stays relatively mild with partly to mostly cloudy skies and lows in the lower to middle 50s.

Friday: Clouds become more variable as the next disturbance and cold front approach from the west. A shower cannot be ruled out, but substantial dry periods are favored, with highs generally in the lower to mid-60s. Cooler and drier air begins arriving Friday night behind the front, with temperatures falling into the upper 30s to around 40°F.

Saturday: A distinctly cooler early-October day follows the frontal passage. High pressure and drier air should favor a mix of sun and clouds, but the cooler air mass will hold highs to the mid- to upper 50s. Saturday night should turn chilly under lighter winds and relatively dry conditions, with lows potentially reaching the lower to mid-30s, particularly in sheltered portions of the Valley.

Weather Notice

Apex Wx forecasts are based on available observations, computer model guidance, and other meteorological data. Conditions and forecast guidance can change, and information displayed here may not reflect the latest official forecast or warning information. Always visit NWS Caribou for the latest official forecasts, watches, warnings, and advisories for northern Maine.

Apex Wx is a private weather information service unaffiliated with NOAA or the National Weather Service and operated by Joseph Becker. Dr. Becker earned a Certificate in Weather Forecasting from Penn State University and is a trained NWS SKYWARN Storm Spotter.

Credits

• Sun and Moon data from the U.S. Naval Observatory, with additional astronomical information from timeanddate.com.
• NOAA warning banner provided by WillyWeather.com.
• Through December 2026, additional archived Apex Wx weather data are available through the University of Utah's MesoWest.
• Current and archived Apex Wx weather data are available through Synoptic Data, the successor to MesoWest.
• Apex Wx logo by Joanna Becker © 2016. Visit Bushi and Brush Arts Dojo.

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