Model accuracy · Snow storm
The October 2026 Montana, Wyoming and Utah snowstorm: which model got the snow right?
In the October 2026 Montana, Wyoming and Utah snowstorm (October 9-14, 2026), National Blend (NBM) had the smallest snowfall miss in Southwest Montana three days ahead, an average miss of 4.8 inches across 93 comparison locations, graded against national snowfall analysis. The top models were too close to call.
The largest reported totals among the graded places were Great Falls International (16.0 inches), Melville 4W (13.6 inches). At lead day 1, NAM 3 km had the smallest average difference in Southwest Montana (5.0 inches against national snowfall analysis). That comparison was too close to call a clear winner. 95% of the graded snow-event comparisons were too close to call.
- Observer reports
- 71
- new-snow measurements on the map
- Most snow measured
- 16 inches
- Great Falls International
- Models graded
- 10
- historical snow estimates
- Storm dates
- October 9-14, 2026
- graded Oct 15
Most snow measured
- 1Great Falls International16 inchestown, Cascade County below 5000ft
- 2Melville 4W14 inchestown, Melville Foothills
- 3Bynum 4 Sse11 inchestown, Southern High Plains
- 4Stanford11 inchestown, Judith Basin County and Judith Gap
- 5Helena 2.0 NNW10 inchestown, Helena Valley
- 6Choteau10 inchestown, Southern High Plains
- 7Wilsall 0.3 NW9.8 inchestown, Northern Park
- 8Livingston 6.6 ESE9.5 inchestown, Livingston Area
- 9Bozeman 1.5 SSE9 inchestown, Gallatin Valley
- 10Melville 10.1 ENE9 inchestown, Northern Sweet Grass
Storm totals from new-snow observers. Dots are placed to about 3 miles. Area rankings below can use different locations and a gridded snowfall estimate.
Results by region and mountain range
The three models with the smallest average snowfall miss at lead-day brackets 1, 3 and 5 before each measurement day. Day 1 uses a model run initialized within the preceding 24 hours. A clear winner must pass the separation test and the required observation cross-check.
Southwest Montana
Whole region · 11 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 193 places | Too close to call | NAM 3 km5.0 in average miss | HRRR5.1 in average miss | NOAA AI-GFS5.3 in average miss |
| Day 393 places | Too close to call | National Blend (NBM)4.8 in average miss | NOAA AI-GFS4.9 in average miss | ECMWF (Euro)5.4 in average miss |
| Day 593 places | Too close to call | NOAA AI-GFS6.8 in average miss | National Blend (NBM)7.0 in average miss | Canadian (GDPS)7.4 in average miss |
Big Belt, Bridger & Castle Mountains
Mountains · 21 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 17 places | Too close to call | NAM 3 km4.8 in average miss | HRRR6.2 in average miss | ECMWF (Euro)7.9 in average miss |
| Day 37 places | Too close to call | ECMWF (Euro)9.5 in average miss | National Blend (NBM)9.9 in average miss | NOAA AI-GFS10.6 in average miss |
| Day 57 places | Too close to call | NOAA AI-GFS14.5 in average miss | National Blend (NBM)14.6 in average miss | Canadian (GDPS)16.7 in average miss |
Gallatin, Madison & Centennial Mountains
Mountains · 12 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 119 places | Too close to call | NOAA AI-GFS3.9 in average miss | NAM 12 km4.1 in average miss | ECMWF AIFS4.3 in average miss |
| Day 319 places | Too close to call | NOAA AI-GFS3.0 in average miss | NAM 12 km3.9 in average miss | GFS4.3 in average miss |
| Day 519 places | Too close to call | NOAA AI-GFS6.7 in average miss | National Blend (NBM)7.4 in average miss | ECMWF (Euro)7.5 in average miss |
Elkhorn & Boulder Mountains
Mountains · 11 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 18 places | Too close to call | NAM 3 km3.6 in average miss | Canadian (GDPS)3.9 in average miss | HRRR4.2 in average miss |
| Day 38 places | Too close to call | Canadian (GDPS)3.2 in average miss | National Blend (NBM)4.1 in average miss | NAM 12 km4.3 in average miss |
| Day 58 places | Too close to call | Canadian (GDPS)5.9 in average miss | National Blend (NBM)6.0 in average miss | NOAA AI-GFS6.6 in average miss |
Absaroka-Beartooth Mountains
Mountains · 10 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 112 places | Too close to call | GFS3.6 in average miss | HRRR4.0 in average miss | ECMWF AIFS4.1 in average miss |
| Day 312 places | Too close to call | National Blend (NBM)3.2 in average miss | GFS3.2 in average miss | ECMWF (Euro)3.8 in average miss |
| Day 512 places | Too close to call | GFS2.8 in average miss | ECMWF (Euro)4.1 in average miss | National Blend (NBM)4.3 in average miss |
Rocky Mountain Front & North-Central Montana
Whole region · 9.9 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 186 places | Too close to call | NAM 3 km3.3 in average miss | ECMWF (Euro)3.8 in average miss | NAM 12 km3.8 in average miss |
| Day 386 places | Too close to call | ECMWF (Euro)3.8 in average miss | ECMWF AIFS4.0 in average miss | NOAA AI-GFS5.0 in average miss |
| Day 586 places | Too close to call | National Blend (NBM)5.3 in average miss | Canadian (GDPS)5.6 in average miss | NOAA AI-GFS6.8 in average miss |
Little Belt & Highwood Mountains
Mountains · 26 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 17 places | Too close to call | NAM 3 km8.4 in average miss | HRRR10.2 in average miss | ECMWF (Euro)10.5 in average miss |
| Day 37 places | Too close to call | NOAA AI-GFS11.1 in average miss | NAM 12 km12.9 in average miss | ECMWF (Euro)13.1 in average miss |
| Day 57 places | Too close to call | National Blend (NBM)17.2 in average miss | NOAA AI-GFS17.3 in average miss | Canadian (GDPS)17.6 in average miss |
Rocky Mountain Front
Mountains · 14 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 113 places | Too close to call | ECMWF (Euro)3.8 in average miss | National Blend (NBM)3.9 in average miss | NAM 12 km4.6 in average miss |
| Day 313 places | Too close to call | ECMWF (Euro)4.1 in average miss | ECMWF AIFS4.6 in average miss | National Blend (NBM)5.4 in average miss |
| Day 513 places | Too close to call | National Blend (NBM)4.3 in average miss | Canadian (GDPS)7.6 in average miss | GFS8.2 in average miss |
Eastern Toole and Liberty
Valleys and towns · 4.4 inches average reference snowfall. Graded against snow observers.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 17 places | Too close to call | NAM 12 km0.9 in average miss | NAM 3 km1.2 in average miss | NOAA AI-GFS1.3 in average miss |
| Day 37 places | Too close to call | Canadian (GDPS)1.2 in average miss | National Blend (NBM)1.3 in average miss | NOAA AI-GFS1.7 in average miss |
| Day 57 places | Clear winner | Canadian (GDPS)1.1 in average miss | National Blend (NBM)1.8 in average miss | ECMWF (Euro)3.0 in average miss |
Northwest Montana
Whole region · 2.8 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 199 places | Too close to call | National Blend (NBM)1.1 in average miss | NAM 3 km1.4 in average miss | NOAA AI-GFS1.6 in average miss |
| Day 399 places | Too close to call | National Blend (NBM)1.4 in average miss | NOAA AI-GFS1.7 in average miss | GFS1.7 in average miss |
| Day 599 places | Too close to call | National Blend (NBM)1.4 in average miss | NOAA AI-GFS1.6 in average miss | Canadian (GDPS)1.8 in average miss |
Bitterroot & Sapphire Mountains
Mountains · 7.2 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 117 places | Too close to call | ECMWF (Euro)2.3 in average miss | NAM 3 km2.5 in average miss | NOAA AI-GFS2.6 in average miss |
| Day 317 places | Too close to call | NOAA AI-GFS2.3 in average miss | GFS2.5 in average miss | National Blend (NBM)2.9 in average miss |
| Day 517 places | Too close to call | NOAA AI-GFS3.8 in average miss | Canadian (GDPS)3.9 in average miss | ECMWF (Euro)4.0 in average miss |
Glacier & Northwest Montana Ranges
Mountains · 1.3 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 131 places | Too close to call | National Blend (NBM)0.7 in average miss | ECMWF AIFS0.8 in average miss | Canadian (GDPS)0.9 in average miss |
| Day 331 places | Too close to call | National Blend (NBM)0.9 in average miss | ECMWF AIFS0.9 in average miss | NOAA AI-GFS1.0 in average miss |
| Day 531 places | Too close to call | National Blend (NBM)0.7 in average miss | ECMWF AIFS0.8 in average miss | Canadian (GDPS)0.9 in average miss |
Northwest Wyoming
Whole region · 2.8 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 1122 places | Too close to call | HRRR1.6 in average miss | NAM 3 km1.7 in average miss | National Blend (NBM)2.0 in average miss |
| Day 3122 places | Too close to call | National Blend (NBM)2.2 in average miss | ECMWF (Euro)2.2 in average miss | Canadian (GDPS)2.5 in average miss |
| Day 5122 places | Too close to call | National Blend (NBM)2.3 in average miss | Canadian (GDPS)2.4 in average miss | GFS2.7 in average miss |
Salt River & Wyoming Ranges
Mountains · 6.9 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 110 places | Too close to call | HRRR2.3 in average miss | GFS3.1 in average miss | NAM 3 km3.7 in average miss |
| Day 310 places | Too close to call | ECMWF AIFS4.4 in average miss | ECMWF (Euro)4.9 in average miss | GFS5.2 in average miss |
| Day 510 places | Too close to call | ECMWF (Euro)4.0 in average miss | ECMWF AIFS5.5 in average miss | NOAA AI-GFS5.5 in average miss |
Absaroka Mountains
Mountains · 6.6 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 113 places | Too close to call | NAM 3 km3.0 in average miss | HRRR3.3 in average miss | RAP3.5 in average miss |
| Day 313 places | Too close to call | National Blend (NBM)3.8 in average miss | ECMWF (Euro)3.9 in average miss | ECMWF AIFS4.7 in average miss |
| Day 513 places | Too close to call | National Blend (NBM)3.3 in average miss | NOAA AI-GFS3.7 in average miss | ECMWF AIFS4.2 in average miss |
Wind River Range
Mountains · 6.6 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 115 places | Too close to call | ECMWF (Euro)2.9 in average miss | NAM 3 km3.0 in average miss | National Blend (NBM)3.6 in average miss |
| Day 315 places | Too close to call | ECMWF AIFS3.6 in average miss | National Blend (NBM)4.2 in average miss | Canadian (GDPS)4.3 in average miss |
| Day 515 places | Too close to call | ECMWF AIFS3.4 in average miss | NOAA AI-GFS3.8 in average miss | National Blend (NBM)4.3 in average miss |
Teton & Gros Ventre Mountains
Mountains · 3.9 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 115 places | Too close to call | HRRR1.9 in average miss | ECMWF (Euro)1.9 in average miss | Canadian (GDPS)2.2 in average miss |
| Day 315 places | Too close to call | ECMWF (Euro)2.9 in average miss | ECMWF AIFS3.0 in average miss | GFS3.0 in average miss |
| Day 515 places | Too close to call | National Blend (NBM)2.5 in average miss | ECMWF (Euro)2.5 in average miss | NOAA AI-GFS2.7 in average miss |
Yellowstone Plateau
Mountains · 1.3 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 116 places | Too close to call | National Blend (NBM)0.8 in average miss | Canadian (GDPS)0.9 in average miss | RAP0.9 in average miss |
| Day 316 places | Clear winner | National Blend (NBM)0.7 in average miss | Canadian (GDPS)1.2 in average miss | ECMWF (Euro)1.4 in average miss |
| Day 516 places | Clear winner | Canadian (GDPS)0.9 in average miss | National Blend (NBM)1.5 in average miss | GFS3.0 in average miss |
Northern Utah
Whole region · 2.7 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 1220 places | Too close to call | National Blend (NBM)1.4 in average miss | HRRR1.4 in average miss | NAM 3 km1.4 in average miss |
| Day 3220 places | Too close to call | National Blend (NBM)1.6 in average miss | Canadian (GDPS)1.9 in average miss | NAM 12 km2.0 in average miss |
| Day 5220 places | Too close to call | Canadian (GDPS)2.0 in average miss | National Blend (NBM)2.1 in average miss | ECMWF (Euro)2.3 in average miss |
Uinta Mountains
Mountains · 7.1 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 133 places | Too close to call | National Blend (NBM)2.2 in average miss | HRRR2.8 in average miss | ECMWF (Euro)3.0 in average miss |
| Day 333 places | Too close to call | NAM 12 km2.4 in average miss | National Blend (NBM)3.0 in average miss | Canadian (GDPS)3.4 in average miss |
| Day 533 places | Too close to call | Canadian (GDPS)4.0 in average miss | ECMWF AIFS4.3 in average miss | ECMWF (Euro)4.4 in average miss |
Wasatch Mountains
Mountains · 5.3 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 154 places | Too close to call | NAM 3 km2.6 in average miss | HRRR2.8 in average miss | National Blend (NBM)3.6 in average miss |
| Day 354 places | Too close to call | National Blend (NBM)3.7 in average miss | Canadian (GDPS)3.7 in average miss | ECMWF AIFS4.3 in average miss |
| Day 554 places | Too close to call | National Blend (NBM)4.4 in average miss | Canadian (GDPS)4.4 in average miss | ECMWF AIFS4.5 in average miss |
Central & Southern Utah
Whole region · 2.5 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 1128 places | Too close to call | National Blend (NBM)1.3 in average miss | NAM 3 km1.7 in average miss | RAP1.8 in average miss |
| Day 3128 places | Too close to call | National Blend (NBM)1.7 in average miss | Canadian (GDPS)2.2 in average miss | ECMWF AIFS2.2 in average miss |
| Day 5128 places | Too close to call | National Blend (NBM)2.0 in average miss | ECMWF (Euro)2.1 in average miss | GFS2.2 in average miss |
Southern Utah Mountains
Mountains · 6.8 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 131 places | Too close to call | National Blend (NBM)2.2 in average miss | Canadian (GDPS)3.7 in average miss | RAP3.8 in average miss |
| Day 331 places | Too close to call | National Blend (NBM)4.7 in average miss | GFS4.8 in average miss | NAM 12 km5.3 in average miss |
| Day 531 places | Too close to call | GFS4.2 in average miss | ECMWF (Euro)5.3 in average miss | Canadian (GDPS)5.6 in average miss |
La Sal & Abajo Mountains
Mountains · 4.7 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 17 places | Too close to call | National Blend (NBM)3.3 in average miss | NAM 3 km3.3 in average miss | HRRR3.8 in average miss |
| Day 37 places | Too close to call | GFS4.3 in average miss | National Blend (NBM)4.4 in average miss | Canadian (GDPS)4.6 in average miss |
| Day 57 places | Too close to call | ECMWF (Euro)4.4 in average miss | Canadian (GDPS)4.4 in average miss | National Blend (NBM)4.5 in average miss |
Wasatch Plateau & Central Mountains
Mountains · 2.7 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 137 places | Too close to call | ECMWF AIFS1.7 in average miss | ECMWF (Euro)1.7 in average miss | GFS1.8 in average miss |
| Day 337 places | Too close to call | National Blend (NBM)1.0 in average miss | ECMWF AIFS1.9 in average miss | NOAA AI-GFS1.9 in average miss |
| Day 537 places | Too close to call | National Blend (NBM)1.7 in average miss | ECMWF AIFS1.8 in average miss | ECMWF (Euro)2.2 in average miss |
Central Idaho Mountains
Whole region · 1.8 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 174 places | Too close to call | HRRR0.9 in average miss | National Blend (NBM)1.1 in average miss | NAM 3 km1.3 in average miss |
| Day 374 places | Too close to call | National Blend (NBM)1.3 in average miss | NOAA AI-GFS1.6 in average miss | NAM 12 km1.7 in average miss |
| Day 574 places | Too close to call | National Blend (NBM)1.3 in average miss | ECMWF (Euro)1.4 in average miss | NOAA AI-GFS1.6 in average miss |
Central Idaho Mountains
Mountains · 1.1 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 144 places | Too close to call | HRRR0.7 in average miss | National Blend (NBM)0.7 in average miss | NOAA AI-GFS0.9 in average miss |
| Day 344 places | Too close to call | National Blend (NBM)0.8 in average miss | NOAA AI-GFS0.9 in average miss | NAM 12 km1.1 in average miss |
| Day 544 places | Too close to call | National Blend (NBM)0.8 in average miss | NOAA AI-GFS0.9 in average miss | ECMWF AIFS0.9 in average miss |
Eastern Montana
Whole region · 1.4 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 1113 places | Too close to call | HRRR0.7 in average miss | RAP0.8 in average miss | ECMWF (Euro)0.9 in average miss |
| Day 3113 places | Too close to call | ECMWF (Euro)0.8 in average miss | National Blend (NBM)1.2 in average miss | NOAA AI-GFS1.3 in average miss |
| Day 5113 places | Too close to call | Canadian (GDPS)1.2 in average miss | National Blend (NBM)1.5 in average miss | ECMWF AIFS1.8 in average miss |
Other areas
Snowy Range & Sierra Madre
Mountains · 3.3 inches average reference snowfall. Graded against national snowfall analysis.
| Forecast made | Result | 1st | 2nd | 3rd |
|---|---|---|---|---|
| Day 117 places | Too close to call | RAP2.4 in average miss | HRRR2.5 in average miss | NAM 3 km2.6 in average miss |
| Day 317 places | Too close to call | NOAA AI-GFS2.5 in average miss | National Blend (NBM)2.7 in average miss | ECMWF (Euro)2.8 in average miss |
| Day 517 places | Too close to call | ECMWF (Euro)2.6 in average miss | National Blend (NBM)2.7 in average miss | Canadian (GDPS)2.9 in average miss |
NOAA AI-GFS has no snowfall forecast of its own, so its snow is 10 inches for every inch of precipitation it forecast.
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How this storm was graded
Day 1 uses the newest model initialization within the 24 hours before each measurement day starts. Day 3 uses the 48-72 hour bracket before that day, and Day 5 the 96-120 hour bracket. Daily estimates are added over the storm, so later days can use runs initialized after the storm began. These retrospective archive comparisons do not establish when a forecast was available to users.
Town and area estimates use published snow depth where available. Snow-water fields are converted at 10:1; GFS and GEFS estimate snow water from precipitation and a snow-category field. Models without a snow field use precipitation at 10:1. Resort and pass comparisons use height-adjusted historical estimates; ensemble estimates from averaged inputs can differ from Ski Forecast, which converts each member before averaging.
Town-area rankings use snow observers: CoCoRaHS volunteers, National Weather Service cooperative observers and official weather stations. Mountain and regional rankings use NOAA's National Snowfall Analysis, a gridded estimate built from observations and model guidance. Mountain rankings are checked against NRCS SNOTEL snow-depth gain, which is affected by settling and is not a fresh-snow measurement. Resort snow reports are not used; agreement with the analysis is not independent resort validation.
Questions about this storm
Which weather model got the snow right in the October 2026 Northern Rockies snowstorm?
In the October 2026 Montana, Wyoming and Utah snowstorm (October 9-14, 2026), National Blend (NBM) had the smallest snowfall miss in Southwest Montana three days ahead, an average miss of 4.8 inches across 93 comparison locations, graded against national snowfall analysis. The top models were too close to call. Three days ahead, by region: Central & Southern Utah: National Blend (NBM) (too close to call); Central Idaho Mountains: National Blend (NBM) (too close to call); Eastern Montana: ECMWF (Euro) (too close to call); Northern Utah: National Blend (NBM) (too close to call); Northwest Montana: National Blend (NBM) (too close to call); Northwest Wyoming: National Blend (NBM) (too close to call); Rocky Mountain Front & North-Central Montana: ECMWF (Euro) (too close to call); Southwest Montana: National Blend (NBM) (too close to call).
How much snow fell?
The most measured was 16 inches at Great Falls International (Cascade County below 5000ft). 71 places measured the storm's snow.
What does Day 1 mean?
Day 1 uses the newest model initialization within the 24 hours before each measurement day starts. Day 3 uses the 48-72 hour bracket before that day, and Day 5 the 96-120 hour bracket. Daily estimates are added over the storm, so later days can use runs initialized after the storm began. These retrospective archive comparisons do not establish when a forecast was available to users.
What does "too close to call" mean?
It means the smallest average miss did not pass the separation test, or the required second comparison was missing or disagreed. A clear winner needs at least five comparison locations, a margin over the runner-up of at least the larger of half an inch or 10% of the mean snowfall, and a paired 90% uncertainty interval above zero. Mountains and regions also need the same top model in the observation cross-check. This describes the selected storm and reference data, not general forecast superiority.
Where do the measurements and estimates come from?
Town-area rankings use snow observers: CoCoRaHS volunteers, National Weather Service cooperative observers and official weather stations. Mountain and regional rankings use NOAA's National Snowfall Analysis, a gridded estimate built from observations and model guidance. Mountain rankings are checked against NRCS SNOTEL snow-depth gain, which is affected by settling and is not a fresh-snow measurement. Resort snow reports are not used; agreement with the analysis is not independent resort validation.
Measurements and estimates
- CoCoRaHS. Volunteer snow observers
- NWS Cooperative Observer Program. Daily snowfall from cooperative observers
- NRCS SNOTEL. Mountain snow-depth gain; not a fresh-snow measurement
- NOHRSC National Snowfall Analysis. NOAA's gridded snowfall estimate, including model guidance