upslopeSeptember 1, 2026 New England rain event — forecast vs. what fell
event hit rate 57%
MAE 0.32″
30 mountains scored
On September 1, 2026, 8 of 30 scored New England ski resorts recorded measurable rain, peaking at 0.25″ near Stratton. upslope’s day-before forecasts verified at a 57% event hit rate with a mean absolute error of 0.32″ across 30 mountains. Ground truth: median of CoCoRaHS volunteer gauges near each resort (min 2 reporting).
Mountain by mountain
| Resort | Forecast | Measured | Error | Call |
|---|---|---|---|---|
| StrattonVT | 0.86″ | 0.25″ | +0.61″ | ✓ |
| BromleyVT | 0.77″ | 0.24″ | +0.53″ | ✓ |
| Mount SnowVT | 0.96″ | 0.21″ | +0.75″ | ✓ |
| Berkshire EastMA | 0.78″ | 0.2″ | +0.58″ | ✓ |
| Magic MountainVT | 0.79″ | 0.19″ | +0.6″ | ✓ |
| Mount SunapeeNH | 0.45″ | 0.18″ | +0.27″ | ✓ |
| OkemoVT | 0.55″ | 0.14″ | +0.41″ | ✓ |
| KillingtonVT | 0.58″ | 0.11″ | +0.47″ | ✓ |
| PicoVT | 0.52″ | 0.08″ | +0.44″ | ✗ |
| WachusettMA | 0.88″ | 0.05″ | +0.83″ | ✗ |
| Pats PeakNH | 0.45″ | 0.02″ | +0.43″ | ✗ |
| AttitashNH | 0.09″ | — | +0.09″ | ✓ |
| Black MountainNH | 0.08″ | — | +0.08″ | ✓ |
| Bolton ValleyVT | 0.14″ | — | +0.14″ | ✗ |
| Bretton WoodsNH | 0.06″ | — | +0.06″ | ✓ |
| BurkeVT | 0.05″ | — | +0.05″ | ✓ |
| CannonNH | 0.08″ | — | +0.08″ | ✓ |
| CranmoreNH | 0.08″ | — | +0.08″ | ✓ |
| CrotchedNH | 0.58″ | — | +0.58″ | ✗ |
| GunstockNH | 0.37″ | — | +0.37″ | ✗ |
| Jay PeakVT | 0.03″ | — | +0.03″ | ✓ |
| LoonNH | 0.1″ | — | +0.1″ | ✗ |
| Mad River GlenVT | 0.44″ | — | +0.44″ | ✗ |
| RaggedNH | 0.53″ | — | +0.53″ | ✗ |
| Smugglers' NotchVT | 0.11″ | — | +0.11″ | ✗ |
| StoweVT | 0.12″ | — | +0.12″ | ✗ |
| SugarbushVT | 0.46″ | — | +0.46″ | ✗ |
| Sunday RiverME | 0.03″ | — | +0.03″ | ✓ |
| Waterville ValleyNH | 0.12″ | — | +0.12″ | ✗ |
| WildcatNH | 0.07″ | — | +0.07″ | ✓ |
Forecast = upslope's last published NWS-based rain number the day before. ✓ = correctly called rain above/below 0.1″. Positive error = over-forecast.