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

Washington Reagan · ECMWF IFS HRES · lead day 8

KDCA · ifs_hres · lead 8

Target day = initialization date + 8 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
tmax00Zbilinear30d17 1 QC3.17 [2.69, 3.70]2.76-1.74 [-3.10, 0.52]3.61 [3.03, 4.29]18% [0%, 30%]29%35%+0.28+0.342026-08-09 → 2026-08-30
tmax00Zbilinear90d17 1 QC3.17 [2.24, 3.85]2.76-1.74 [-3.21, 0.63]3.61 [2.38, 4.46]18% [0%, 32%]29%35%+0.28+0.342026-08-09 → 2026-08-30
tmax00Zbilinear365d17 1 QC3.17 [2.24, 3.85]2.76-1.74 [-3.20, 0.84]3.61 [2.38, 4.42]18% [0%, 33%]29%35%+0.28+0.342026-08-09 → 2026-08-30
tmax00Zbilinearall17 1 QC3.17 [2.33, 3.89]2.76-1.74 [-3.28, 1.10]3.61 [2.59, 4.61]18% [0%, 33%]29%35%+0.28+0.342026-08-09 → 2026-08-30
tmax00Znearest30d17 1 QC3.07 [2.45, 3.66]2.88-1.38 [-2.75, 0.82]3.50 [2.93, 4.15]18% [6%, 40%]29%41%+0.30+0.312026-08-09 → 2026-08-30
tmax00Znearest90d17 1 QC3.07 [2.04, 3.85]2.88-1.38 [-2.91, 0.99]3.50 [2.37, 4.34]18% [0%, 56%]29%41%+0.30+0.312026-08-09 → 2026-08-30
tmax00Znearest365d17 1 QC3.07 [2.04, 3.75]2.88-1.38 [-2.92, 1.21]3.50 [2.37, 4.34]18% [0%, 50%]29%41%+0.30+0.312026-08-09 → 2026-08-30
tmax00Znearestall17 1 QC3.07 [2.05, 3.95]2.88-1.38 [-2.96, 1.39]3.50 [2.44, 4.46]18% [0%, 50%]29%41%+0.30+0.312026-08-09 → 2026-08-30
tmax12Zbilinear30d17 1 QC4.97 [3.67, 7.61]3.58-3.32 [-4.70, -2.53]5.92 [4.16, 8.34]0% [0%, 0%]24%35%-0.13+0.142026-08-09 → 2026-08-30
tmax12Zbilinear90d17 1 QC4.97 [3.70, 7.77]3.58-3.32 [-4.97, -2.42]5.92 [4.23, 8.52]0% [0%, 0%]24%35%-0.13+0.142026-08-09 → 2026-08-30
tmax12Zbilinear365d17 1 QC4.97 [3.62, 7.97]3.58-3.32 [-4.97, -2.39]5.92 [4.16, 8.73]0% [0%, 0%]24%35%-0.13+0.142026-08-09 → 2026-08-30
tmax12Zbilinearall17 1 QC4.97 [3.61, 8.37]3.58-3.32 [-4.97, -2.50]5.92 [4.16, 8.81]0% [0%, 0%]24%35%-0.13+0.142026-08-09 → 2026-08-30
tmax12Znearest30d17 1 QC4.72 [3.24, 7.65]3.43-2.73 [-4.15, -1.88]5.76 [3.62, 8.52]0% [0%, 0%]29%41%-0.07+0.182026-08-09 → 2026-08-30
tmax12Znearest90d17 1 QC4.72 [3.23, 7.69]3.43-2.73 [-4.62, -1.74]5.76 [3.63, 8.71]0% [0%, 0%]29%41%-0.07+0.182026-08-09 → 2026-08-30
tmax12Znearest365d17 1 QC4.72 [3.17, 7.94]3.43-2.73 [-4.62, -1.74]5.76 [3.57, 8.87]0% [0%, 0%]29%41%-0.07+0.182026-08-09 → 2026-08-30
tmax12Znearestall17 1 QC4.72 [3.20, 8.45]3.43-2.73 [-4.62, -1.82]5.76 [3.59, 9.12]0% [0%, 0%]29%41%-0.07+0.182026-08-09 → 2026-08-30
tmin00Zbilinear30d17 1 QC3.07 [2.01, 3.65]2.92+0.89 [-0.82, 2.05]3.49 [2.66, 3.87]18% [0%, 56%]24%47%+0.43+0.442026-08-09 → 2026-08-30
tmin00Zbilinear90d17 1 QC3.07 [0.67, 3.69]2.92+0.89 [-0.79, 2.02]3.49 [0.67, 3.89]18% [0%, 100%]24%47%+0.43+0.442026-08-09 → 2026-08-30
tmin00Zbilinear365d17 1 QC3.07 [0.67, 3.72]2.92+0.89 [-0.78, 2.10]3.49 [0.67, 3.91]18% [0%, 100%]24%47%+0.43+0.442026-08-09 → 2026-08-30
tmin00Zbilinearall17 1 QC3.07 [1.08, 3.73]2.92+0.89 [-0.79, 2.49]3.49 [1.41, 3.93]18% [0%, 87%]24%47%+0.43+0.442026-08-09 → 2026-08-30
tmin00Znearest30d17 1 QC2.92 [1.95, 3.48]2.81+0.93 [-0.76, 2.06]3.44 [2.64, 3.79]24% [6%, 56%]35%59%+0.46+0.462026-08-09 → 2026-08-30
tmin00Znearest90d17 1 QC2.92 [0.78, 3.48]2.81+0.93 [-0.78, 2.02]3.44 [0.78, 3.79]24% [0%, 100%]35%59%+0.46+0.462026-08-09 → 2026-08-30
tmin00Znearest365d17 1 QC2.92 [0.78, 3.54]2.81+0.93 [-0.78, 2.06]3.44 [0.78, 3.79]24% [0%, 100%]35%59%+0.46+0.462026-08-09 → 2026-08-30
tmin00Znearestall17 1 QC2.92 [1.02, 3.56]2.81+0.93 [-0.78, 2.47]3.44 [1.31, 3.83]24% [0%, 87%]35%59%+0.46+0.462026-08-09 → 2026-08-30
tmin12Zbilinear30d17 1 QC3.10 [2.18, 3.72]3.20+0.56 [-1.37, 1.98]3.61 [2.36, 4.30]12% [0%, 27%]29%53%+0.43+0.392026-08-09 → 2026-08-30
tmin12Zbilinear90d17 1 QC3.10 [2.09, 3.69]3.20+0.56 [-2.13, 2.00]3.61 [2.23, 4.31]12% [0%, 30%]29%53%+0.43+0.392026-08-09 → 2026-08-30
tmin12Zbilinear365d17 1 QC3.10 [2.09, 3.74]3.20+0.56 [-2.13, 2.05]3.61 [2.25, 4.33]12% [0%, 30%]29%53%+0.43+0.392026-08-09 → 2026-08-30
tmin12Zbilinearall17 1 QC3.10 [2.01, 3.76]3.20+0.56 [-2.13, 2.34]3.61 [2.19, 4.34]12% [0%, 33%]29%53%+0.43+0.392026-08-09 → 2026-08-30
tmin12Znearest30d17 1 QC3.12 [2.10, 3.78]3.24+0.69 [-1.34, 2.20]3.71 [2.24, 4.49]12% [0%, 27%]35%59%+0.42+0.382026-08-09 → 2026-08-30
tmin12Znearest90d17 1 QC3.12 [2.00, 3.76]3.24+0.69 [-2.09, 2.22]3.71 [2.11, 4.47]12% [0%, 30%]35%59%+0.42+0.382026-08-09 → 2026-08-30
tmin12Znearest365d17 1 QC3.12 [2.02, 3.80]3.24+0.69 [-2.09, 2.32]3.71 [2.12, 4.51]12% [0%, 30%]35%59%+0.42+0.382026-08-09 → 2026-08-30
tmin12Znearestall17 1 QC3.12 [1.94, 3.85]3.24+0.69 [-2.09, 2.58]3.71 [2.05, 4.54]12% [0%, 33%]35%59%+0.42+0.382026-08-09 → 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 8, 00Z bilinear tmax+10+50-5-102026-08-09: -1.46 °F2026-08-15: +3.03 °F2026-08-16: +4.65 °F2026-08-17: +1.26 °F2026-08-18: -4.55 °F2026-08-19: -4.61 °F2026-08-20: -0.99 °F2026-08-21: -3.16 °F2026-08-22: +2.48 °F2026-08-23: -3.64 °F2026-08-24: -4.2 °F2026-08-25: -4.07 °F2026-08-26: -0.23 °F2026-08-27: -3.63 °F2026-08-28: -4.25 °F2026-08-29: +0.79 °F2026-08-30: -6.94 °F2026-08-092026-08-30°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 (22 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-6.94
2026-08-29+0.79
2026-08-28-4.25
2026-08-27-3.63
2026-08-26-0.23
2026-08-25-4.07
2026-08-24-4.20
2026-08-23-3.64
2026-08-22+2.48
2026-08-21-3.16
2026-08-20-0.99
2026-08-19-4.61
2026-08-18-4.55
2026-08-17+1.26
2026-08-16+4.65
2026-08-15+3.03
2026-08-14—
2026-08-13—
2026-08-12—
2026-08-11—
2026-08-10—
2026-08-09-1.46

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KDCA, lead day 8-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 1 day-6 to -5 °F: 0 days-5 to -4 °F: 5 days-4 to -3 °F: 3 days-3 to -2 °F: 0 days-2 to -1 °F: 1 day-1 to 0 °F: 2 days0 to 1 °F: 1 day1 to 2 °F: 1 day2 to 3 °F: 1 day3 to 4 °F: 1 day4 to 5 °F: 1 day5 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| 3.63 · P90 |e| 4.63 °F-100+10 °Fn = 17 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
-7.00-6.001
-6.00-5.000
-5.00-4.005
-4.00-3.003
-3.00-2.000
-2.00-1.001
-1.00+0.002
+0.00+1.001
+1.00+2.001
+2.00+3.001
+3.00+4.001
+4.00+5.001
+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
2026-08173.17 -1.74

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17

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 17 -1.72 [-3.32, -0.45] yes
NCEP GFS 17 -2.69 [-4.11, -0.68] yes
GraphCast (IFS init) 17 -4.03 [-6.35, -2.71] yes
Persistence (baseline) 17 -1.24 [-2.54, -0.57] yes

Cite this page

ShortCastCheck, KDCA ifs_hres lead 8, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDCA/model/ifs_hres/lead/8/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDCA (Washington Reagan), model ifs_hres, lead day 8. 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/8/

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

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