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

Washington Reagan · ECMWF IFS HRES · lead day 9

KDCA · ifs_hres · lead 9

Target day = initialization date + 9 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
tmax00Zbilinear30d16 1 QC4.35 [2.93, 6.41]4.00-1.09 [-3.21, 0.92]5.89 [3.40, 7.72]19% [0%, 29%]31%44%+0.03+0.082026-08-10 → 2026-08-30
tmax00Zbilinear90d16 1 QC4.35 [2.88, 6.30]4.00-1.09 [-3.55, 0.93]5.89 [3.40, 7.77]19% [0%, 30%]31%44%+0.03+0.082026-08-10 → 2026-08-30
tmax00Zbilinear365d16 1 QC4.35 [2.88, 6.45]4.00-1.09 [-3.47, 0.98]5.89 [3.40, 7.86]19% [0%, 29%]31%44%+0.03+0.082026-08-10 → 2026-08-30
tmax00Zbilinearall16 1 QC4.35 [2.88, 6.65]4.00-1.09 [-3.48, 0.92]5.89 [3.38, 7.83]19% [0%, 31%]31%44%+0.03+0.082026-08-10 → 2026-08-30
tmax00Znearest30d16 1 QC4.15 [2.66, 6.31]4.01-0.55 [-2.94, 1.57]5.93 [3.08, 7.88]19% [0%, 29%]31%56%+0.08+0.082026-08-10 → 2026-08-30
tmax00Znearest90d16 1 QC4.15 [2.62, 6.18]4.01-0.55 [-3.11, 1.62]5.93 [3.11, 7.99]19% [0%, 30%]31%56%+0.08+0.082026-08-10 → 2026-08-30
tmax00Znearest365d16 1 QC4.15 [2.66, 6.39]4.01-0.55 [-3.11, 1.68]5.93 [3.11, 8.13]19% [0%, 29%]31%56%+0.08+0.082026-08-10 → 2026-08-30
tmax00Znearestall16 1 QC4.15 [2.61, 6.55]4.01-0.55 [-3.11, 1.55]5.93 [3.09, 8.02]19% [0%, 31%]31%56%+0.08+0.082026-08-10 → 2026-08-30
tmax12Zbilinear30d15 1 QC6.14 [2.81, 8.01]4.81-4.72 [-7.61, -1.33]7.77 [3.79, 9.56]7% [0%, 25%]13%27%-0.33-0.042026-08-10 → 2026-08-30
tmax12Zbilinear90d15 1 QC6.14 [1.18, 8.17]4.81-4.72 [-7.91, -1.18]7.77 [1.18, 9.46]7% [0%, 25%]13%27%-0.33-0.042026-08-10 → 2026-08-30
tmax12Zbilinear365d15 1 QC6.14 [1.18, 8.10]4.81-4.72 [-7.90, -1.14]7.77 [1.18, 9.46]7% [0%, 29%]13%27%-0.33-0.042026-08-10 → 2026-08-30
tmax12Zbilinearall15 1 QC6.14 [1.18, 8.38]4.81-4.72 [-8.32, -1.18]7.77 [1.18, 9.57]7% [0%, 32%]13%27%-0.33-0.042026-08-10 → 2026-08-30
tmax12Znearest30d15 1 QC6.00 [2.66, 7.76]4.84-4.20 [-7.17, -0.80]7.54 [3.58, 9.29]13% [0%, 57%]13%20%-0.30-0.052026-08-10 → 2026-08-30
tmax12Znearest90d15 1 QC6.00 [0.77, 7.88]4.84-4.20 [-7.45, -0.71]7.54 [0.77, 9.16]13% [0%, 100%]13%20%-0.30-0.052026-08-10 → 2026-08-30
tmax12Znearest365d15 1 QC6.00 [0.77, 7.88]4.84-4.20 [-7.42, -0.66]7.54 [0.77, 9.18]13% [0%, 100%]13%20%-0.30-0.052026-08-10 → 2026-08-30
tmax12Znearestall15 1 QC6.00 [0.77, 8.06]4.84-4.20 [-7.75, -0.70]7.54 [0.77, 9.25]13% [0%, 100%]13%20%-0.30-0.052026-08-10 → 2026-08-30
tmin00Zbilinear30d16 1 QC3.36 [2.30, 4.47]3.36+1.45 [-0.34, 3.39]4.35 [2.91, 5.40]25% [0%, 36%]44%56%+0.26+0.222026-08-10 → 2026-08-30
tmin00Zbilinear90d16 1 QC3.36 [2.28, 5.58]3.36+1.45 [-0.45, 5.58]4.35 [2.80, 5.75]25% [0%, 35%]44%56%+0.26+0.222026-08-10 → 2026-08-30
tmin00Zbilinear365d16 1 QC3.36 [2.25, 5.23]3.36+1.45 [-0.46, 5.23]4.35 [2.79, 5.55]25% [0%, 36%]44%56%+0.26+0.222026-08-10 → 2026-08-30
tmin00Zbilinearall16 1 QC3.36 [2.08, 5.25]3.36+1.45 [-0.57, 5.25]4.35 [2.61, 5.57]25% [0%, 35%]44%56%+0.26+0.222026-08-10 → 2026-08-30
tmin00Znearest30d16 1 QC3.48 [2.54, 4.53]3.28+1.59 [-0.16, 3.51]4.35 [3.03, 5.35]12% [0%, 27%]38%50%+0.24+0.242026-08-10 → 2026-08-30
tmin00Znearest90d16 1 QC3.48 [2.49, 5.69]3.28+1.59 [-0.37, 5.69]4.35 [2.94, 5.80]12% [0%, 29%]38%50%+0.24+0.242026-08-10 → 2026-08-30
tmin00Znearest365d16 1 QC3.48 [2.44, 5.30]3.28+1.59 [-0.37, 5.30]4.35 [2.91, 5.57]12% [0%, 29%]38%50%+0.24+0.242026-08-10 → 2026-08-30
tmin00Znearestall16 1 QC3.48 [2.35, 5.32]3.28+1.59 [-0.45, 5.32]4.35 [2.78, 5.59]12% [0%, 29%]38%50%+0.24+0.242026-08-10 → 2026-08-30
tmin12Zbilinear30d15 1 QC2.99 [2.16, 3.76]3.01-0.30 [-2.10, 1.79]3.62 [2.76, 4.37]13% [0%, 47%]33%60%+0.30+0.272026-08-10 → 2026-08-30
tmin12Zbilinear90d15 1 QC2.99 [2.16, 4.14]3.01-0.30 [-2.39, 3.49]3.62 [2.82, 4.37]13% [0%, 50%]33%60%+0.30+0.272026-08-10 → 2026-08-30
tmin12Zbilinear365d15 1 QC2.99 [2.12, 4.00]3.01-0.30 [-2.29, 2.81]3.62 [2.71, 4.37]13% [0%, 50%]33%60%+0.30+0.272026-08-10 → 2026-08-30
tmin12Zbilinearall15 1 QC2.99 [1.98, 4.00]3.01-0.30 [-2.37, 2.86]3.62 [2.59, 4.35]13% [0%, 54%]33%60%+0.30+0.272026-08-10 → 2026-08-30
tmin12Znearest30d15 1 QC2.98 [2.19, 3.65]2.98-0.08 [-1.94, 1.99]3.60 [2.80, 4.25]20% [0%, 50%]47%60%+0.30+0.282026-08-10 → 2026-08-30
tmin12Znearest90d15 1 QC2.98 [2.24, 3.98]2.98-0.08 [-2.19, 3.44]3.60 [2.76, 4.27]20% [0%, 50%]47%60%+0.30+0.282026-08-10 → 2026-08-30
tmin12Znearest365d15 1 QC2.98 [2.08, 3.74]2.98-0.08 [-2.08, 2.80]3.60 [2.73, 4.27]20% [0%, 54%]47%60%+0.30+0.282026-08-10 → 2026-08-30
tmin12Znearestall15 1 QC2.98 [1.99, 3.74]2.98-0.08 [-2.15, 2.89]3.60 [2.63, 4.27]20% [0%, 56%]47%60%+0.30+0.282026-08-10 → 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 9, 00Z bilinear tmax+20+100-10-202026-08-10: -3.65 °F2026-08-16: +8.47 °F2026-08-17: -10.02 °F2026-08-18: -3.63 °F2026-08-19: -2.89 °F2026-08-20: -0.23 °F2026-08-21: +15.73 °F2026-08-22: +1.8 °F2026-08-23: -1.95 °F2026-08-24: -0.39 °F2026-08-25: -5.55 °F2026-08-26: -3.09 °F2026-08-27: -3.61 °F2026-08-28: -5.54 °F2026-08-29: +0.12 °F2026-08-30: -2.97 °F2026-08-102026-08-30°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 (21 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.97
2026-08-29+0.12
2026-08-28-5.54
2026-08-27-3.61
2026-08-26-3.09
2026-08-25-5.55
2026-08-24-0.39
2026-08-23-1.95
2026-08-22+1.80
2026-08-21+15.73
2026-08-20-0.23
2026-08-19-2.89
2026-08-18-3.63
2026-08-17-10.02
2026-08-16+8.47
2026-08-15—
2026-08-14—
2026-08-13—
2026-08-12—
2026-08-11—
2026-08-10-3.65

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KDCA, lead day 9-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 1 day-10 to -8 °F: 0 days-8 to -6 °F: 0 days-6 to -4 °F: 2 days-4 to -2 °F: 6 days-2 to 0 °F: 3 days0 to 2 °F: 2 days2 to 4 °F: 0 days4 to 6 °F: 0 days6 to 8 °F: 0 days8 to 10 °F: 1 day10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 1 day16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 3.35 · P90 |e| 9.24 °F-200+20 °Fn = 16 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
-20.00-18.000
-18.00-16.000
-16.00-14.000
-14.00-12.000
-12.00-10.001
-10.00-8.000
-8.00-6.000
-6.00-4.002
-4.00-2.006
-2.00+0.003
+0.00+2.002
+2.00+4.000
+4.00+6.000
+6.00+8.000
+8.00+10.001
+10.00+12.000
+12.00+14.000
+14.00+16.001
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08164.35 -1.09

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-10 → 2026-08-30 16
ECMWF IFS HRES2026-08-10 → 2026-08-30 16
ECMWF IFS HRES2026-08-10 → 2026-08-30 15
ECMWF IFS HRES2026-08-10 → 2026-08-30 15

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 16 -0.78 [-3.34, 3.08] no
NCEP GFS 16 -2.84 [-4.60, 2.26] no
GraphCast (IFS init) 16 -2.53 [-5.55, -0.24] yes
Persistence (baseline) 16 -0.15 [-1.68, 1.66] no

Cite this page

ShortCastCheck, KDCA ifs_hres lead 9, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDCA/model/ifs_hres/lead/9/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDCA (Washington Reagan), model ifs_hres, lead day 9. 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/9/

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

JSON CSV all scores methodology v0.2 licence