SACRUS

2/22 00z Summary Total QPF NYC / Total 10:1 Snow NYC SREF mean: 2.2 / 21 NAM: 2.8 / 27.5 NAM 3k: 2.0 / 19.5 ICON: 1.4 / 13.5 RGEM: 1.3 / 13.3 GFS: 1.6 / 16.7 GFS AI AIGFS: 1.4 / 13.6 GGEM: 1.5 / 13.8 GEFS: 1.7 / 17 UKMET: 1.2 / 11 EURO AI AIFS: 1.3 / 12.7 EURO: 1.4 / 12.8 Total QPF (NYC): 1.65 inches Total Snow (10:1, NYC): 16.0 inches

Biggest difference is the speed NAM-GFS vs RGEM/Euro etc otherwise very similar

2/22 00z EURO Total QPF 2/22-2/23-24 10:1 Snow

Not sure why we split threads keep it all together it al becomes obs by 4pm

2/22 00z Euro Ai AIFS Total QPF 2/22-2/23-24 10:1 Snow

nyc 10+ snowfalls storms NYC (Central Park) Snowstorms ≥ 10.0" 1933–2026 Feb 11, 1933 – 10.0" Dec 26, 1933 – 11.2" Jan 23–24, 1935 – 13.0" Mar 7–8, 1941 – 18.1" Feb 20–21, 1947 – 10.7" Dec 26–27, 1947 – 26.4" Dec 19–20, 1948 – 16.0" Mar 18–19, 1956 – 11.6" Mar 20–21, 1958 – 11.8" Dec 21–22, 1959 – 13.7" Mar 3–4, 1960 – 14.5" Dec 11–12, 1960 – 15.2" Feb 3–4, 1961 – 17.4" Jan 12–13, 1964 – 12.5" Feb 7, 1967 – 12.5" Feb 9–10, 1969 – 15.3" Jan 19–20, 1978 – 13.6" Feb 5–7, 1978 – 17.7" Feb 19, 1979 – 12.7" Feb 11–12, 1983 – 17.6" Mar 13–14, 1993 – 10.6" Feb 11, 1994 – 12.8" Feb 4, 1995 – 10.8" Jan 7–8, 1996 – 20.2" Feb 16–17, 1996 – 10.7" Dec 30, 2000 – 12.0" Feb 16–17, 2003 – 19.8" Dec 5–7, 2003 – 14.0" Jan 27–28, 2004 – 10.3" Jan 22–23, 2005 – 13.8" Feb 11–12, 2006 – 26.9" Dec 19–20, 2009 – 10.9" Feb 10, 2010 – 10.0" Feb 25–27, 2010 – 20.9" Dec 26–27, 2010 – 20.0" Jan 26–27, 2011 – 19.0" Feb 8–9, 2013 – 11.4" Jan 21–22, 2014 – 11.5" Feb 13–14, 2014 – 12.5" Jan 22–24, 2016 – 27.5" Dec 16–17, 2020 – 10.5" Jan 31–Feb 3, 2021 – 17.4" Jan 25–26, 2026 – 11.4"

2/22 00z UKMET Total QPF 2/22-2/23-24 10:1 Snow

GEFS more robust than GFS

2/22 00z GEFS Total QPF 2/22-2/23-24 Mean Snow 10:1

Font forget 2003

Updated

2/22 00z GGEM Total QPF 2/22-2/23-24 10:1 Snow

2/22 00z GFS AI AIGFS Total QPF 2/22 -2/23-2/24 10:1 Snow

2/22 00z GFS Total QPF 2/22 - 2/23-2/24 10:1 Snow

2/22 00z WRF Total QPF 2/22 - 2/23-24 10:1 Snow

2/22 00z RGEM Total QPF 2/22-2/23-24 10:1 Snow

Updated ICON

2/22 00z ICON Total QPF 2/22-2/23-24 10:1 Snow

2/22 00z NAM 3k Total QPF 2/22 - 2/23-24 S10:1 Snow

Updated NAM

2/22 00z NAM Total QPF 2/22 - 2/23-24 10:1 Snow

Snowside Heights and Snow Pleasant crushed in NJ

sref were a good precursor the nam would remain robust

What it is: The National Blend of Models (NBM) is NOAA/NWS’s statistically post-processed blend that combines dozens of deterministic and ensemble models into a single, calibrated forecast grid used operationally across the U.S. Models included: Core inputs typically include GFS, GEFS, ECMWF (Euro), ECMWF ensembles, NAM (12 km & 3 km), HRRR, RAP, CMC/GEM, UKMET, and select regional ensembles (availability varies by cycle and variable). Weighting approach: Dynamic, variable-specific weighting is applied—models are weighted differently by forecast hour, parameter (QPF, snow, wind, temp), season, region, and recent skill, rather than a fixed average. Post-processing & bias correction: Raw model output is statistically bias-corrected, smoothed, and calibrated using historical verification, climatology, and consistency checks to reduce noise, outliers, and known model biases. Operational output: Produces probabilistic and deterministic fields (means, percentiles, PoPs, snowfall ranges) and serves as the baseline guidance for NWS forecast grids, with human forecasters adjusting for mesoscale and event-specific factors.