upslopeSeptember 2, 2026 New England rain event — forecast vs. what fell
event hit rate 56%
MAE 0.11″
32 mountains scored
On September 2, 2026, 14 of 32 scored New England ski resorts recorded measurable rain, peaking at 0.69″ near Berkshire East. upslope’s day-before forecasts verified at a 56% event hit rate with a mean absolute error of 0.11″ across 32 mountains. Ground truth: median of CoCoRaHS volunteer gauges near each resort (min 2 reporting).
Mountain by mountain
| Resort | Forecast | Measured | Error | Call |
|---|---|---|---|---|
| Berkshire EastMA | — | 0.69″ | -0.69″ | ✗ |
| CrotchedNH | 0.05″ | 0.36″ | -0.31″ | ✗ |
| Pats PeakNH | 0.02″ | 0.3″ | -0.28″ | ✗ |
| WachusettMA | 0.05″ | 0.3″ | -0.25″ | ✗ |
| Magic MountainVT | 0.04″ | 0.27″ | -0.23″ | ✗ |
| Mount SnowVT | 0.07″ | 0.27″ | -0.2″ | ✗ |
| OkemoVT | 0.05″ | 0.27″ | -0.22″ | ✗ |
| Bretton WoodsNH | — | 0.23″ | -0.23″ | ✗ |
| Mount SunapeeNH | 0.04″ | 0.23″ | -0.19″ | ✗ |
| BromleyVT | 0.05″ | 0.21″ | -0.16″ | ✗ |
| StrattonVT | 0.05″ | 0.2″ | -0.15″ | ✗ |
| KillingtonVT | 0.03″ | 0.15″ | -0.12″ | ✗ |
| PicoVT | 0.02″ | 0.15″ | -0.13″ | ✗ |
| RaggedNH | 0.07″ | 0.13″ | -0.06″ | ✗ |
| GunstockNH | 0.01″ | 0.06″ | -0.05″ | ✓ |
| Waterville ValleyNH | 0.01″ | 0.01″ | 0.0″ | ✓ |
| AttitashNH | 0.03″ | — | +0.03″ | ✓ |
| Black MountainNH | — | — | 0.0″ | ✓ |
| Bolton ValleyVT | 0.02″ | — | +0.02″ | ✓ |
| BurkeVT | — | — | 0.0″ | ✓ |
| CannonNH | — | — | 0.0″ | ✓ |
| CranmoreNH | 0.05″ | — | +0.05″ | ✓ |
| Jay PeakVT | 0.01″ | — | +0.01″ | ✓ |
| LoonNH | 0.01″ | — | +0.01″ | ✓ |
| Mad River GlenVT | 0.01″ | — | +0.01″ | ✓ |
| SaddlebackME | — | — | 0.0″ | ✓ |
| Smugglers' NotchVT | 0.02″ | — | +0.02″ | ✓ |
| StoweVT | 0.02″ | — | +0.02″ | ✓ |
| SugarbushVT | 0.01″ | — | +0.01″ | ✓ |
| SugarloafME | — | — | 0.0″ | ✓ |
| Sunday RiverME | — | — | 0.0″ | ✓ |
| WildcatNH | 0.01″ | — | +0.01″ | ✓ |
Forecast = upslope's last published NWS-based rain number the day before. ✓ = correctly called rain above/below 0.1″. Positive error = over-forecast.