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CastCheck methodology v0.2 · data through 2026-08-30

Washington Reagan · ECMWF IFS HRES · lead day 0

KDCA · ifs_hres · lead 0

Target day = initialization date + 0 days. This page is a permanent link: the numbers change as history accumulates, the address and the methodology version do not.

Scores use the latest model version segment, ifs-gpid161, starting 2026-08-01 — days before that ran a different version of the model and are excluded rather than silently pooled. Of the scored days, 1 carry a QC flag on the observation.

JSON for this page CSV of the daily errors Cite this page

Every number for this combination

All four windows × both initializations × both interpolations × both variables. Errors are computed in °C and shown in °F; CI is a 95 % moving-block bootstrap interval. MAE debiased and skill, debiased remove the constant offset of the window first, so a station that the model always reads a degree too warm is not scored as if it had no skill — compare the two skill columns to see how much of the error is a fixed offset. n QC next to n counts days whose observation carries a QC flag.

VariableInitMethod Windown MAE °F MAE debiased Bias °F RMSE °F ±1 °F±2 °F±3 °F Skill Skill, debiased Period
tmax00Zbilinear30d24 1 QC2.93 [1.86, 3.67]2.54-1.91 [-3.44, 0.07]3.47 [2.28, 4.11]17% [4%, 33%]38%54%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d24 1 QC2.93 [1.47, 3.69]2.54-1.91 [-3.52, 0.43]3.47 [1.75, 4.13]17% [5%, 42%]38%54%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d24 1 QC2.93 [1.44, 3.71]2.54-1.91 [-3.59, 0.43]3.47 [1.73, 4.15]17% [3%, 40%]38%54%——2026-08-01 → 2026-08-30
tmax00Zbilinearall24 1 QC2.93 [1.42, 3.71]2.54-1.91 [-3.55, 0.42]3.47 [1.69, 4.14]17% [5%, 45%]38%54%——2026-08-01 → 2026-08-30
tmax00Znearest30d24 1 QC2.99 [1.80, 3.77]2.78-1.46 [-3.18, 0.68]3.56 [2.19, 4.32]17% [4%, 39%]33%58%——2026-08-01 → 2026-08-30
tmax00Znearest90d24 1 QC2.99 [1.48, 3.75]2.78-1.46 [-3.27, 0.96]3.56 [1.79, 4.37]17% [6%, 50%]33%58%——2026-08-01 → 2026-08-30
tmax00Znearest365d24 1 QC2.99 [1.46, 3.77]2.78-1.46 [-3.32, 1.03]3.56 [1.73, 4.40]17% [5%, 50%]33%58%——2026-08-01 → 2026-08-30
tmax00Znearestall24 1 QC2.99 [1.34, 3.73]2.78-1.46 [-3.34, 0.95]3.56 [1.63, 4.36]17% [5%, 60%]33%58%——2026-08-01 → 2026-08-30
tmin00Zbilinear30d24 1 QC1.60 [1.14, 2.14]1.58+0.06 [-1.12, 1.15]2.27 [1.71, 2.71]58% [32%, 79%]71%83%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d24 1 QC1.60 [1.14, 2.34]1.58+0.06 [-1.50, 1.31]2.27 [1.63, 2.83]58% [23%, 77%]71%83%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d24 1 QC1.60 [1.10, 2.35]1.58+0.06 [-1.78, 1.32]2.27 [1.42, 2.84]58% [25%, 79%]71%83%——2026-08-01 → 2026-08-30
tmin00Zbilinearall24 1 QC1.60 [1.08, 2.35]1.58+0.06 [-1.54, 1.36]2.27 [1.36, 2.77]58% [17%, 81%]71%83%——2026-08-01 → 2026-08-30
tmin00Znearest30d24 1 QC1.65 [1.23, 2.11]1.64+0.14 [-1.13, 1.27]2.25 [1.70, 2.65]46% [32%, 65%]71%79%——2026-08-01 → 2026-08-30
tmin00Znearest90d24 1 QC1.65 [1.17, 2.32]1.64+0.14 [-1.53, 1.40]2.25 [1.58, 2.78]46% [25%, 71%]71%79%——2026-08-01 → 2026-08-30
tmin00Znearest365d24 1 QC1.65 [1.10, 2.30]1.64+0.14 [-1.73, 1.40]2.25 [1.39, 2.77]46% [24%, 70%]71%79%——2026-08-01 → 2026-08-30
tmin00Znearestall24 1 QC1.65 [1.06, 2.30]1.64+0.14 [-1.69, 1.39]2.25 [1.29, 2.75]46% [25%, 74%]71%79%——2026-08-01 → 2026-08-30

+ model too warm · − model too cold · bias interval includes zero · ★ lowest MAE · = not distinguishable from the leader · ▼ significantly worse · n < 30 greyed and unranked · CI is a 95 % moving-block bootstrap interval.

Daily error, last 90 days

Daily forecast minus observed error in °F for ECMWF IFS HRES at KDCA, lead day 0, 00Z bilinear tmax+10+50-5-102026-08-01: -0.67 °F2026-08-08: -0.06 °F2026-08-09: -2.2 °F2026-08-10: +2.51 °F2026-08-11: +1.75 °F2026-08-12: +1.03 °F2026-08-13: +1.65 °F2026-08-14: +3.85 °F2026-08-15: +1.03 °F2026-08-16: -5.84 °F2026-08-17: -5.53 °F2026-08-18: -3.1 °F2026-08-19: -2.64 °F2026-08-20: -5.75 °F2026-08-21: -4.23 °F2026-08-22: -0.72 °F2026-08-23: -5.68 °F2026-08-24: -5.38 °F2026-08-25: -3.08 °F2026-08-26: +0.4 °F2026-08-27: -4.61 °F2026-08-28: -4.35 °F2026-08-29: -2.96 °F2026-08-30: -1.34 °F2026-08-012026-08-30°F, forecast − observed
Forecast − observed, °F, 00Z bilinear daily maximum. The dashed line is zero; the thick line is a centred 7-day mean, drawn only where the whole window is present. Gaps are days with no score, never interpolation. Hover a point for its date and value.
The same series as a table (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.34
2026-08-29-2.96
2026-08-28-4.35
2026-08-27-4.61
2026-08-26+0.40
2026-08-25-3.08
2026-08-24-5.38
2026-08-23-5.68
2026-08-22-0.72
2026-08-21-4.23
2026-08-20-5.75
2026-08-19-2.64
2026-08-18-3.10
2026-08-17-5.53
2026-08-16-5.84
2026-08-15+1.03
2026-08-14+3.85
2026-08-13+1.65
2026-08-12+1.03
2026-08-11+1.75
2026-08-10+2.51
2026-08-09-2.20
2026-08-08-0.06
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04—
2026-08-03—
2026-08-02—
2026-08-01-0.67

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KDCA, lead day 0-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 5 days-5 to -4 °F: 3 days-4 to -3 °F: 2 days-3 to -2 °F: 3 days-2 to -1 °F: 1 day-1 to 0 °F: 3 days0 to 1 °F: 1 day1 to 2 °F: 4 days2 to 3 °F: 1 day3 to 4 °F: 1 day4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 2.8 · P90 |e| 5.64 °F-100+10 °Fn = 24 days
All scored days for 00Z bilinear daily maximum, 20 equal bins. The dashed marks are the 50th and 90th percentiles of the absolute error, mirrored on both sides. Hover a bar for its bin and count.
Bin counts as a table
From °FTo °FDays
-10.00-9.000
-9.00-8.000
-8.00-7.000
-7.00-6.000
-6.00-5.005
-5.00-4.003
-4.00-3.002
-3.00-2.003
-2.00-1.001
-1.00+0.003
+0.00+1.001
+1.00+2.004
+2.00+3.001
+3.00+4.001
+4.00+5.000
+5.00+6.000
+6.00+7.000
+7.00+8.000
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08242.93 -1.91

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-01 → 2026-08-30 24
ECMWF IFS HRES2026-08-01 → 2026-08-30 24

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF IFS HRES has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 24 +0.69 [0.05, 0.99] yes
Aurora (GFS init) 2 -4.49 [-5.75, -3.23] yes
Aurora (IFS init) 3 -3.72 [-5.00, -2.81] yes
FourCastNet v2 (GFS init) 2 -1.99 [-3.14, -0.84] yes
FourCastNet v2 (IFS init) 3 -2.82 [-3.99, -2.24] yes
NCEP GFS 24 +1.00 [-0.17, 1.64] no
GraphCast (GFS init) 2 -3.79 [-3.79, -3.78] yes
GraphCast (IFS init) 22 -1.78 [-3.06, -1.27] yes
Pangu-Weather (GFS init) 2 -0.06 [-1.71, 1.58] no
Pangu-Weather (IFS init) 3 +0.09 [-1.92, 1.09] no

Cite this page

ShortCastCheck, KDCA ifs_hres lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDCA/model/ifs_hres/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDCA (Washington Reagan), model ifs_hres, lead day 0. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KDCA/model/ifs_hres/lead/0/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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