upslope

September 14, 2026 New England rain event — forecast vs. what fell

event hit rate 19% MAE 0.28″ 32 mountains scored

On September 14, 2026, 24 of 32 scored New England ski resorts recorded measurable rain, peaking at 1.21″ near Wachusett. upslope’s day-before forecasts verified at a 19% event hit rate with a mean absolute error of 0.28″ across 32 mountains. Ground truth: median of CoCoRaHS volunteer gauges near each resort (min 2 reporting).

Mountain by mountain

Resort Forecast Measured Error Call
WachusettMA0.05″1.21″-1.16″✗
Berkshire EastMA0.06″0.89″-0.83″✗
CrotchedNH—0.88″-0.88″✗
Waterville ValleyNH0.01″0.57″-0.56″✗
Mount SunapeeNH—0.55″-0.55″✗
Pats PeakNH—0.53″-0.53″✗
RaggedNH—0.53″-0.53″✗
LoonNH0.02″0.5″-0.48″✗
GunstockNH—0.42″-0.42″✗
Mount SnowVT0.03″0.33″-0.3″✗
Jay PeakVT0.13″0.3″-0.17″✓
Magic MountainVT0.03″0.29″-0.26″✗
AttitashNH—0.28″-0.28″✗
CranmoreNH—0.28″-0.28″✗
OkemoVT0.02″0.25″-0.23″✗
StrattonVT0.07″0.25″-0.18″✗
Black MountainNH—0.24″-0.24″✗
BromleyVT0.06″0.24″-0.18″✗
Sunday RiverME—0.18″-0.18″✗
WildcatNH0.03″0.18″-0.15″✗
Bretton WoodsNH0.05″0.14″-0.09″✗
PicoVT0.05″0.11″-0.06″✗
BurkeVT0.06″0.1″-0.04″✗
CannonNH0.02″0.1″-0.08″✗
KillingtonVT0.06″0.08″-0.02″✓
SaddlebackME0.16″0.07″+0.09″✗
SugarloafME0.05″0.07″-0.02″✓
Smugglers' NotchVT0.05″0.03″+0.02″✓
StoweVT0.12″0.03″+0.09″✗
SugarbushVT0.05″0.03″+0.02″✓
Bolton ValleyVT0.13″0.01″+0.12″✗
Mad River GlenVT0.06″0.01″+0.05″✓

Forecast = upslope's last published NWS-based rain number the day before. ✓ = correctly called rain above/below 0.1″. Positive error = over-forecast.