MJO phase 2 · PDO negative · seasonal odds, not guarantees
Thu, Oct 22, 12 AM → Fri 12 AM · 24 h
Each model’s precip that falls above its snow level counts as snow, at a ratio set by the warmest temperature between the ground and 500 hPa. NAM and NBM have no snow level or column, so they use their own snowfall at 7:1 and are marked “raw”. Raw 7:1 shows every model’s own snowfall.
↘Trending less snowy: blend down 1.1″ over the last 8 cycles (6 of 10 models agree).
Latest blend 2.2 in · Kuchera ratio · 10 models
Time-based lookback is fairer across models: 10 HRRR runs span ~1 day, 10 GFS runs span 2.5 days.
| Model | Latest | vs prev | vs first |
|---|---|---|---|
| GFS7 runs · 12Z | 2.2 | +0.4 | -0.5 |
| HRRR2 runs · 18Z | 5.7 | -7.6 | -7.6 |
| ECMWF IFS 9km7 runs · 12Z | 1.4 | -0.4 | +0.7 |
| ECMWF IFS 0.25°7 runs · 12Z | 3.7 | +0.5 | +1.4 |
| ECMWF AIFS7 runs · 12Z | 3.9 | 0 | -2.5 |
| ICON8 runs · 18Z | 2.0 | +0.9 | -2.1 |
| GEM Global3 runs · 12Z | 5.2 | +0.3 | -0.8 |
| UKMO 10km5 runs · 12Z | 1.1 | +0.7 | -4.2 |
| NAM 3km4 runs · 18Z · raw | 2.1 | -0.2 | +0.3 |
| NBM15 runs · 18Z · raw | 2.1 | -0.8 | -1.2 |
A run counts only if it covers the whole window, so short-range models (HRRR, NAM, HRDPS) appear only for windows within ~2 days. The blend uses each model’s latest run at or before every 00/06/12/18Z cycle, and is hidden where fewer than 3 models contribute.