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

Washington Reagan · ECMWF IFS HRES · lead day 6

KDCA · ifs_hres · lead 6

Target day = initialization date + 6 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
tmax00Zbilinear30d19 1 QC4.71 [3.89, 5.62]3.76-2.00 [-3.53, -0.22]5.48 [4.12, 6.98]0% [0%, 0%]11%11%+0.05+0.212026-08-07 → 2026-08-30
tmax00Zbilinear90d19 1 QC4.71 [3.46, 5.61]3.76-2.00 [-3.62, -0.18]5.48 [3.64, 6.91]0% [0%, 0%]11%11%+0.05+0.212026-08-07 → 2026-08-30
tmax00Zbilinear365d19 1 QC4.71 [3.50, 5.63]3.76-2.00 [-3.65, 0.10]5.48 [3.75, 6.96]0% [0%, 0%]11%11%+0.05+0.212026-08-07 → 2026-08-30
tmax00Zbilinearall19 1 QC4.71 [3.55, 5.66]3.76-2.00 [-3.61, -0.01]5.48 [3.58, 7.07]0% [0%, 0%]11%11%+0.05+0.212026-08-07 → 2026-08-30
tmax00Znearest30d19 1 QC4.65 [3.64, 5.73]3.82-1.73 [-3.29, 0.17]5.57 [3.99, 7.31]0% [0%, 0%]5%26%+0.06+0.202026-08-07 → 2026-08-30
tmax00Znearest90d19 1 QC4.65 [3.35, 5.70]3.82-1.73 [-3.38, 0.22]5.57 [3.58, 7.23]0% [0%, 0%]5%26%+0.06+0.202026-08-07 → 2026-08-30
tmax00Znearest365d19 1 QC4.65 [3.34, 5.76]3.82-1.73 [-3.44, 0.46]5.57 [3.48, 7.27]0% [0%, 0%]5%26%+0.06+0.202026-08-07 → 2026-08-30
tmax00Znearestall19 1 QC4.65 [3.32, 5.80]3.82-1.73 [-3.37, 0.42]5.57 [3.47, 7.42]0% [0%, 0%]5%26%+0.06+0.202026-08-07 → 2026-08-30
tmax12Zbilinear30d19 1 QC3.54 [2.73, 4.18]2.77-2.13 [-3.78, 0.23]4.23 [3.20, 5.09]16% [0%, 33%]16%37%+0.28+0.422026-08-07 → 2026-08-30
tmax12Zbilinear90d19 1 QC3.54 [2.59, 4.27]2.77-2.13 [-4.07, 0.40]4.23 [3.00, 5.16]16% [0%, 38%]16%37%+0.28+0.422026-08-07 → 2026-08-30
tmax12Zbilinear365d19 1 QC3.54 [2.57, 4.36]2.77-2.13 [-4.07, 0.76]4.23 [3.00, 5.25]16% [0%, 39%]16%37%+0.28+0.422026-08-07 → 2026-08-30
tmax12Zbilinearall19 1 QC3.54 [2.63, 4.28]2.77-2.13 [-4.07, 0.58]4.23 [2.97, 5.20]16% [0%, 38%]16%37%+0.28+0.422026-08-07 → 2026-08-30
tmax12Znearest30d19 1 QC3.17 [2.39, 3.84]2.60-1.61 [-3.08, 0.53]3.81 [2.69, 4.67]11% [0%, 33%]16%58%+0.36+0.452026-08-07 → 2026-08-30
tmax12Znearest90d19 1 QC3.17 [2.21, 3.90]2.60-1.61 [-3.19, 0.68]3.81 [2.50, 4.73]11% [0%, 38%]16%58%+0.36+0.452026-08-07 → 2026-08-30
tmax12Znearest365d19 1 QC3.17 [2.21, 3.96]2.60-1.61 [-3.22, 1.00]3.81 [2.47, 4.85]11% [0%, 39%]16%58%+0.36+0.452026-08-07 → 2026-08-30
tmax12Znearestall19 1 QC3.17 [2.21, 3.94]2.60-1.61 [-3.32, 0.87]3.81 [2.42, 4.74]11% [0%, 38%]16%58%+0.36+0.452026-08-07 → 2026-08-30
tmin00Zbilinear30d19 1 QC2.98 [2.16, 3.50]2.93+0.35 [-1.72, 2.42]3.68 [2.60, 4.41]11% [0%, 33%]42%53%+0.40+0.422026-08-07 → 2026-08-30
tmin00Zbilinear90d19 1 QC2.98 [1.58, 3.48]2.93+0.35 [-1.89, 2.67]3.68 [2.05, 4.45]11% [0%, 50%]42%53%+0.40+0.422026-08-07 → 2026-08-30
tmin00Zbilinear365d19 1 QC2.98 [1.48, 3.49]2.93+0.35 [-1.84, 2.74]3.68 [1.97, 4.47]11% [0%, 50%]42%53%+0.40+0.422026-08-07 → 2026-08-30
tmin00Zbilinearall19 1 QC2.98 [1.41, 3.44]2.93+0.35 [-1.88, 2.75]3.68 [1.78, 4.43]11% [0%, 46%]42%53%+0.40+0.422026-08-07 → 2026-08-30
tmin00Znearest30d19 1 QC2.95 [2.02, 3.48]2.91+0.51 [-1.61, 2.60]3.65 [2.50, 4.42]16% [4%, 38%]42%53%+0.41+0.422026-08-07 → 2026-08-30
tmin00Znearest90d19 1 QC2.95 [1.40, 3.47]2.91+0.51 [-1.88, 2.89]3.65 [1.83, 4.42]16% [0%, 50%]42%53%+0.41+0.422026-08-07 → 2026-08-30
tmin00Znearest365d19 1 QC2.95 [1.37, 3.47]2.91+0.51 [-1.88, 2.96]3.65 [1.89, 4.48]16% [0%, 50%]42%53%+0.41+0.422026-08-07 → 2026-08-30
tmin00Znearestall19 1 QC2.95 [1.34, 3.45]2.91+0.51 [-1.80, 2.95]3.65 [1.63, 4.43]16% [0%, 48%]42%53%+0.41+0.422026-08-07 → 2026-08-30
tmin12Zbilinear30d19 1 QC2.66 [1.52, 3.35]2.66-0.01 [-1.98, 1.89]3.49 [2.08, 4.31]26% [11%, 60%]47%63%+0.47+0.472026-08-07 → 2026-08-30
tmin12Zbilinear90d19 1 QC2.66 [0.95, 3.36]2.66-0.01 [-2.06, 2.02]3.49 [0.98, 4.36]26% [11%, 86%]47%63%+0.47+0.472026-08-07 → 2026-08-30
tmin12Zbilinear365d19 1 QC2.66 [0.77, 3.50]2.66-0.01 [-2.19, 2.27]3.49 [0.77, 4.38]26% [8%, 100%]47%63%+0.47+0.472026-08-07 → 2026-08-30
tmin12Zbilinearall19 1 QC2.66 [0.77, 3.46]2.66-0.01 [-2.19, 2.34]3.49 [0.77, 4.29]26% [8%, 100%]47%63%+0.47+0.472026-08-07 → 2026-08-30
tmin12Znearest30d19 1 QC2.76 [1.43, 3.53]2.76+0.15 [-1.95, 2.15]3.69 [1.97, 4.63]26% [11%, 60%]53%58%+0.45+0.452026-08-07 → 2026-08-30
tmin12Znearest90d19 1 QC2.76 [0.92, 3.54]2.76+0.15 [-2.04, 2.25]3.69 [1.14, 4.67]26% [11%, 86%]53%58%+0.45+0.452026-08-07 → 2026-08-30
tmin12Znearest365d19 1 QC2.76 [0.67, 3.65]2.76+0.15 [-2.21, 2.53]3.69 [0.67, 4.72]26% [8%, 100%]53%58%+0.45+0.452026-08-07 → 2026-08-30
tmin12Znearestall19 1 QC2.76 [0.67, 3.59]2.76+0.15 [-2.20, 2.57]3.69 [0.67, 4.57]26% [8%, 100%]53%58%+0.45+0.452026-08-07 → 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 6, 00Z bilinear tmax+20+100-10-202026-08-07: -3.09 °F2026-08-13: -6.01 °F2026-08-14: +1.2 °F2026-08-15: -3.89 °F2026-08-16: +14.77 °F2026-08-17: -5 °F2026-08-18: -3.07 °F2026-08-19: -3.17 °F2026-08-20: +4.25 °F2026-08-21: -7.82 °F2026-08-22: +1.6 °F2026-08-23: -4.59 °F2026-08-24: -4.29 °F2026-08-25: -3.92 °F2026-08-26: -3.66 °F2026-08-27: -5.32 °F2026-08-28: -6.25 °F2026-08-29: +3.96 °F2026-08-30: -3.61 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.61
2026-08-29+3.96
2026-08-28-6.25
2026-08-27-5.32
2026-08-26-3.66
2026-08-25-3.92
2026-08-24-4.29
2026-08-23-4.59
2026-08-22+1.60
2026-08-21-7.82
2026-08-20+4.25
2026-08-19-3.17
2026-08-18-3.07
2026-08-17-5.00
2026-08-16+14.77
2026-08-15-3.89
2026-08-14+1.20
2026-08-13-6.01
2026-08-12—
2026-08-11—
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07-3.09

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KDCA, lead day 6-20 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: 0 days-10 to -8 °F: 0 days-8 to -6 °F: 3 days-6 to -4 °F: 4 days-4 to -2 °F: 7 days-2 to 0 °F: 0 days0 to 2 °F: 2 days2 to 4 °F: 1 day4 to 6 °F: 1 day6 to 8 °F: 0 days8 to 10 °F: 0 days10 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| 3.96 · P90 |e| 6.57 °F-200+20 °Fn = 19 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
-12.00-10.000
-10.00-8.000
-8.00-6.003
-6.00-4.004
-4.00-2.007
-2.00+0.000
+0.00+2.002
+2.00+4.001
+4.00+6.001
+6.00+8.000
+8.00+10.000
+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
2026-08194.71 -2.00

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-07 → 2026-08-30 19
ECMWF IFS HRES2026-08-07 → 2026-08-30 19
ECMWF IFS HRES2026-08-07 → 2026-08-30 19
ECMWF IFS HRES2026-08-07 → 2026-08-30 19

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 19 +0.25 [-0.88, 2.15] no
NCEP GFS 19 +1.29 [-0.77, 2.05] no
GraphCast (IFS init) 19 -0.50 [-2.12, 1.19] no
Persistence (baseline) 19 -0.24 [-1.04, 0.99] no

Cite this page

ShortCastCheck, KDCA ifs_hres lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDCA/model/ifs_hres/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDCA (Washington Reagan), model ifs_hres, lead day 6. 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/6/

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