ToMorrowSnow
Data statusStatus

Predictions

Our forecast

CHANGEME

One or two sentences: what our main forecast is, in the owner's words.

Inner band: 1 chance in 2; outer band: 8 in 10. Behind it, the typical season, 1985–86 to 2025–26.

Where this comes from

Snow so far from NRCS SNOTEL snow pillows, after quality checks. Each of the 41 past winters counts once. The forecast is remade each morning from the data available that morning and stored unchanged.

01020304050 inOctDecFebApr
01020304050 inOctNovDecJanFebMarApr
01020304050 inOctNovDecJanFebMarApr

Our main forecast30 AprHow good is this?

Snow water
29 in (728 mm)
8-in-10 range
17–48 in
Estimated snowfall
120–480 in

Snow so far: The map starts once the pillows usually hold about 2 inches of water, around mid-November.

Outside agencies' forecasts

Months shown

NMME average

Issued Oct 2026

Nov 2026–Mar 2027 precipitation, % of normal

130 % Tahoe box, Nov–Mar

November 2026 precipitation, % of normal

98 % Tahoe box, November

December 2026 precipitation, % of normal

138 % Tahoe box, December

January 2027 precipitation, % of normal

153 % Tahoe box, January

February 2027 precipitation, % of normal

138 % Tahoe box, February

March 2027 precipitation, % of normal

112 % Tahoe box, March

% of normal
← drierwetter →

Track record here: no clear skill

How good is this?

What is NMME?
Name
NMME, the North American Multi-Model Ensemble
What it is
Not one model: a set of US and Canadian seasonal models, each run many times. The NMME average here is our equal-weight average of them.
Models (runs each)
  • CFSv2, NOAA NCEP (24)
  • CanESM5, ECCC (CanSIPS) (20)
  • GEM5.2-NEMO, ECCC (CanSIPS) (20)
  • GEOS-S2S-2, NASA GMAO (10)
  • CCSM4, NCAR / U. Miami (10)
  • CESM1, NCAR (10)
  • SPEAR, NOAA GFDL (30)
Issued
Monthly; the files appear around the 7th
Looks ahead
9–12 months (CFSv2 10, GEOS-S2S-2 9, the others 12)
Grid
1° cells
Used here
Precipitation, from the models' public real-time files

CHANGEME

Spell out the centres' names (NCEP, ECCC, NASA GMAO, NCAR, GFDL); they are not in our research notes.

Where this comes from

NMME data: Kirtman, B. P., and co-authors (2014), The North American Multimodel Ensemble: Phase-1 seasonal-to-interannual prediction; Phase-2 toward developing intraseasonal prediction, Bull. Amer. Meteor. Soc., 95(4), 585-601, doi:10.1175/BAMS-D-12-00050.1. The NMME project and data dissemination is supported by NOAA, NSF, NASA and DOE. We acknowledge the help of NCEP, IRI and NCAR personnel in creating, updating and maintaining the NMME archive, and thank the modelling groups (ECCC, NASA GMAO, NOAA GFDL, NOAA NCEP, NCAR, University of Miami) for their model output. The NMME average and all values here are computed by this site; they are not NOAA products and imply no NOAA endorsement.

SEAS5

Issued Oct 2026

Nov 2026–Mar 2027 precipitation, % of normal

127 % Tahoe box, Nov–Mar

November 2026 precipitation, % of normal

113 % Tahoe box, November

December 2026 precipitation, % of normal

102 % Tahoe box, December

January 2027 precipitation, % of normal

154 % Tahoe box, January

February 2027 precipitation, % of normal

118 % Tahoe box, February

March 2027 precipitation, % of normal

145 % Tahoe box, March

% of normal
← drierwetter →

Track record here: no clear skill

How good is this?

What is SEAS5?
Name
SEAS5, the fifth seasonal forecast system of ECMWF (the European Centre for Medium-Range Weather Forecasts); version 51
What it is
One model, run many times; each run is one member of the ensemble
Runs
51 each month
Issued
Monthly; each forecast starts on the 1st
Looks ahead
6 months, as monthly values
Grid
1° cells
Used here
Precipitation, from the Copernicus Climate Change Service
Where this comes from

Dots: each run's forecast for the Tahoe box, as % of normal. Ring: their average. Grey band: the middle third of normal.

This model's normal mixes SEAS5's past re-runs (starts up to December 2016) with its live forecasts (from January 2017).

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. ECMWF SEAS5 (system 51) from: Copernicus Climate Change Service, Climate Data Store (2018): Seasonal forecast monthly statistics on single levels. Copernicus Climate Change Service (C3S) Climate Data Store (CDS), DOI: 10.24381/cds.68dd14c3. Licence: CC-BY 4.0. This site turned the data into anomalies and snow amounts for its area.

Normal: each model's own forecasts, winters 1991–92 to 2020–21; NMME averages its models' %. Grey: within 10 %. Square: Tahoe box. 1° cells.

Chances, not amounts

Season shown

CPC official outlook

Issued Oct 2026

Nov 2026–Jan 2027: chance of each third
Wetter
35 %
Middle
33 %
Drier
32 %
Dec 2026–Feb 2027: chance of each third
Wetter
45 %
Middle
33 %
Drier
22 %
Jan–Mar 2027: chance of each third
Wetter
48 %
Middle
33 %
Drier
19 %
Favoured third, %

Blank: equal chances. Square: Tahoe box.

Track record here: too few winters to judge

What is CPC's outlook?
Name
The official seasonal outlook of NOAA's Climate Prediction Center (NOAA: the US National Oceanic and Atmospheric Administration)
What it is
Not a model run and not an amount: NOAA forecasters' consensus on the chance that the season falls in the wetter (above normal), middle or drier (below normal) third
Runs
None: made by people, so it has no re-runs for past years
Issued
Monthly, near mid-month (the third Thursday)
Looks ahead
13 overlapping three-month seasons, from half a month to 12½ months ahead
Grid
None: CPC draws areas on a map; this site places them on 0.25° cells
Used here
Precipitation, its first three seasons
Where this comes from

NWS terms (weather.gov/disclaimer): do not claim it as your own, do not imply NOAA or NWS endorsement, and do not modify it and present it as official.

NOAA Climate Prediction Center official 3-month outlooks (US public domain). The odds are CPC's; this site placed them on 0.25° cells and computed the area odds and scores, so these are not official NOAA or NWS material and imply no NOAA or NWS endorsement.