Atkinson, New Hampshire 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

940
FXUS61 KGYX 211744
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
144 PM EDT Thu Aug 21 2025

.SYNOPSIS...
High pressure will maintain fair weather over the region into
the weekend. Long period swell from distant Hurricane Erin will
continue to build into the weekend and will be slow to subside
early next week. A slow moving cold front will bring increasing
chances for showers late Sunday into Monday. Troughing will
linger over the Northeast through the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Satellite-derived precipitable water from GOES 16 shows a much drier
airmass across the region today with PWATS mostly under 0.75" except
over southern NH and the far north where a little more moisture has
a allowed a cumulus field to develop. For the rest of the afternoon,
dry and mostly sunny conditions will prevail with this drier air in
place, but we`ll see if there is enough moisture for a couple of
showers to develop in the mountains as some meso models are hinting
at. Latest satellite imagery does show some growth to the cu field,
so I have added a slight chance of showers this afternoon near the
Canadian Border. If heading to the coast, please remember there is a
HIGH risk of rip currents from building, long-periods swells from
distant Hurricane Erin.

Diurnal cu will dissipate by sunset, and light winds and mostly
clear skies will probably yield overnight conditions similar to
those of last night and this morning...low temperatures mostly in
the 40s with valley fog.   Closer to the coast, expect enough of a
breeze to keep things more mixed as the pressure gradient tightens
with distant Erin moving to the northeast over the western Atlantic.
So temperatures near the coast are forecast to be a little milder
and in the 50s.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
A ridge of high pressure builds into New England on Friday as Erin
continues moving to the northeast over the western Atlantic. This
will bring another day of plentiful sunshine with high temperatures
warming back into the 80-85F range for most of the area based on
850mb temps of +13C to +14C.

As a reminder for those that might be heading to the coast on the
warm sunny day, the large swells from Erin will make surf conditions
even more dangerous than today with large breaking waves and a
high risk of dangerous rip currents. Entering the ocean is
strongly discouraged. Also, the large waves can present a danger
to people on rocks above the water as the waves can easily
sweep people into the cold ocean water. Minor coastal flooding
and splash-over is possible during the late evening high tide
(see section below).

Otherwise, light winds and clear skies will allow radiational
cooling, but it won`t get quite as cool as tonight with light
southerly return flow. Most will see lows in the 50s with a few
40s possible in northern valleys. Valley fog is also likely
again, especially along the CT River.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
High pressure stretched along the Northeast coast will continue to
provide fair weather Saturday. High pressure moves east Sunday as a
trough deepens over the Great Lakes. This trough will slowly migrate
east through the middle of next week and will send a frontal system
across New England late Sunday through Monday. Cyclonic flow aloft
will linger through the end of the period that will maintain low
chances for showers with a cooling trend into next Wednesday.

High surf and dangerous rip currents will be the primary hazards
Saturday. High pressure will bring fair weather with
temperatures climbing into the mid 80s. Sunday looks to remain
mostly dry as a frontal system over the Great Lakes will be slow
to move east. Southerly winds will become breezy Sunday,
especially along the coast towards central Maine where gusts
will approach 30 mph. Clouds and rainfall chances will increase
west to east late Sunday with showers likely Sunday night
through Monday. Ensembles continue to suggest much of the area
will see measurable rainfall, while even the high end QPF
members suggest this rainfall will do little to reduce the
precipitation deficits that have been building over the past two
month.

Th trough axis will remain west of New England Tuesday with
embedded waves bringing continued chances of showers. The trough
will move overhead Wednesday for a cooling and drying trend. The
latest round of NWP guidance suggest the trough will linger
through the end of next week with additional waves rotating
through the trough that could bring additional chances for
showers.

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
Short Term...Mainly VFR through Friday night other than valley
fog at HIE and LEB tonight and again Friday night.

Long Term...Mainly VFR Saturday into Sunday. A cold front
crosses late Sunday and Monday with lowering cigs and showers
bringing the potential for at least MVFR conditions. Strong
southerly flow ahead of the front will also bring the threat of
wind shear Sunday into Monday morning.

&&

.MARINE...
Short Term...Conditions will continue to deteriorate to SCA
levels today and tonight as large, long-period swells from
Hurricane Erin continue to build seas over the waters and bays.
There may also be a period of north to northeast winds gusting
to around 25 kt tonight and into Friday morning, mainly over the
outer waters. SCA conditions persist Friday and Friday night.

Long Term...Long period swell from Erin will be on the downward
trend Saturday while seas will continue to run above 5 feet
into Sunday. Southerly flow ahead of a cold front will ramp up
Sunday with wind gusts likely continuing SCA conditions into
Sunday night. Winds and seas drop below SCA thresholds Monday.

&&

.TIDES/COASTAL FLOODING...
High astronomical tides and up to 2 feet of storm surge may
produce minor coastal flooding and splash-over during the late
Friday evening high tide, and a Coastal Flood Advisory has been
issued.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...High Risk for Rip Currents until 8 PM EDT this evening for
     MEZ023>027.
     High Surf Advisory from 6 AM Friday to 8 PM EDT Saturday for
     MEZ023>028.
     Coastal Flood Advisory from 10 PM Friday to 1 AM EDT Saturday
     for MEZ023>028.
NH...High Risk for Rip Currents until 8 PM EDT this evening for NHZ014.
     High Surf Advisory from 6 AM Friday to 8 PM EDT Saturday for
     NHZ014.
     Coastal Flood Advisory from 10 PM Friday to 1 AM EDT Saturday
     for NHZ014.
MARINE...Small Craft Advisory until 8 PM EDT Saturday for ANZ150-152.
     Small Craft Advisory from 8 PM this evening to 8 PM EDT
     Saturday for ANZ151-154.
     Small Craft Advisory from 2 AM Friday to 8 PM EDT Saturday for
     ANZ153.

&&

$$

NEAR TERM...Combs
SHORT TERM...Combs
LONG TERM...Schroeter
TIDES/COASTAL FLOODING...Combs