upslope

October 17, 2026 New England rain event — forecast vs. what fell

event hit rate 100% MAE 0.33″ 32 mountains scored

On October 17, 2026, 32 of 32 scored New England ski resorts recorded measurable rain, peaking at 0.7″ near Wildcat. upslope’s day-before forecasts verified at a 100% event hit rate with a mean absolute error of 0.33″ across 32 mountains. Ground truth: median of CoCoRaHS volunteer gauges near each resort (min 2 reporting).

Mountain by mountain

Resort	Forecast	Measured	Error	Call
WildcatNH	0.75″	0.7″	+0.05″	✓
SaddlebackME	0.79″	0.68″	+0.11″	✓
SugarloafME	0.87″	0.68″	+0.19″	✓
Bretton WoodsNH	0.54″	0.62″	-0.08″	✓
Jay PeakVT	0.9″	0.54″	+0.36″	✓
BurkeVT	0.57″	0.45″	+0.12″	✓
CannonNH	0.57″	0.43″	+0.14″	✓
WachusettMA	0.65″	0.41″	+0.24″	✓
Bolton ValleyVT	0.7″	0.36″	+0.34″	✓
SugarbushVT	0.57″	0.36″	+0.21″	✓
Berkshire EastMA	0.54″	0.35″	+0.19″	✓
AttitashNH	0.53″	0.34″	+0.19″	✓
Smugglers' NotchVT	0.78″	0.34″	+0.44″	✓
Waterville ValleyNH	0.75″	0.34″	+0.41″	✓
StoweVT	0.87″	0.33″	+0.54″	✓
Mad River GlenVT	0.58″	0.32″	+0.26″	✓
LoonNH	0.75″	0.3″	+0.45″	✓
StrattonVT	0.81″	0.29″	+0.52″	✓
CrotchedNH	0.38″	0.28″	+0.1″	✓
Magic MountainVT	0.62″	0.28″	+0.34″	✓
Mount SnowVT	0.98″	0.28″	+0.7″	✓
BromleyVT	0.89″	0.27″	+0.62″	✓
KillingtonVT	0.82″	0.27″	+0.55″	✓
PicoVT	0.75″	0.27″	+0.48″	✓
Black MountainNH	0.57″	0.2″	+0.37″	✓
CranmoreNH	0.49″	0.2″	+0.29″	✓
GunstockNH	0.6″	0.2″	+0.4″	✓
OkemoVT	0.49″	0.2″	+0.29″	✓
Sunday RiverME	0.72″	0.2″	+0.52″	✓
Pats PeakNH	0.43″	0.19″	+0.24″	✓
Mount SunapeeNH	0.58″	0.15″	+0.43″	✓
RaggedNH	0.49″	0.15″	+0.34″	✓

Forecast = upslope's NWS-based rain forecast for the same 7am-to-7am window the gauges measure, from the last run before that window opened. ✓ = correctly called rain above/below 0.1″. Positive error = over-forecast.