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

Washington Reagan · ECMWF AIFS Single · lead day 6

KDCA · aifs_single · 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, aifs-single-gpid5, 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 QC3.79 [2.11, 5.12]2.57-3.15 [-4.63, -1.65]4.68 [2.91, 5.93]8% [0%, 19%]38%46%+0.22+0.472026-08-07 → 2026-08-30
tmax00Zbilinear90d24 1 QC3.79 [1.54, 5.24]2.57-3.15 [-4.83, -1.20]4.68 [1.90, 6.05]8% [0%, 21%]38%46%+0.22+0.472026-08-07 → 2026-08-30
tmax00Zbilinear365d24 1 QC3.79 [1.40, 5.26]2.57-3.15 [-4.93, -1.28]4.68 [1.63, 6.11]8% [0%, 21%]38%46%+0.22+0.472026-08-07 → 2026-08-30
tmax00Zbilinearall24 1 QC3.79 [1.67, 5.28]2.57-3.15 [-4.72, -1.26]4.68 [2.20, 6.12]8% [0%, 20%]38%46%+0.22+0.472026-08-07 → 2026-08-30
tmax00Znearest30d24 1 QC3.60 [1.94, 4.91]2.58-2.91 [-4.44, -1.43]4.52 [2.76, 5.76]12% [0%, 28%]38%46%+0.26+0.472026-08-07 → 2026-08-30
tmax00Znearest90d24 1 QC3.60 [1.37, 5.06]2.58-2.91 [-4.64, -0.97]4.52 [1.80, 5.91]12% [0%, 31%]38%46%+0.26+0.472026-08-07 → 2026-08-30
tmax00Znearest365d24 1 QC3.60 [1.20, 5.06]2.58-2.91 [-4.74, -1.02]4.52 [1.48, 6.00]12% [0%, 32%]38%46%+0.26+0.472026-08-07 → 2026-08-30
tmax00Znearestall24 1 QC3.60 [1.48, 5.07]2.58-2.91 [-4.62, -1.01]4.52 [2.06, 5.95]12% [0%, 31%]38%46%+0.26+0.472026-08-07 → 2026-08-30
tmax12Zbilinear30d24 1 QC3.70 [2.44, 4.79]2.53-2.60 [-3.69, -1.53]4.48 [3.08, 5.49]17% [0%, 35%]25%46%+0.24+0.482026-08-07 → 2026-08-30
tmax12Zbilinear90d24 1 QC3.70 [2.12, 4.89]2.53-2.60 [-3.97, -1.42]4.48 [2.68, 5.56]17% [0%, 39%]25%46%+0.24+0.482026-08-07 → 2026-08-30
tmax12Zbilinear365d24 1 QC3.70 [2.16, 5.07]2.53-2.60 [-4.01, -1.47]4.48 [2.69, 5.68]17% [0%, 38%]25%46%+0.24+0.482026-08-07 → 2026-08-30
tmax12Zbilinearall24 1 QC3.70 [2.21, 5.02]2.53-2.60 [-3.82, -1.42]4.48 [2.73, 5.63]17% [0%, 39%]25%46%+0.24+0.482026-08-07 → 2026-08-30
tmax12Znearest30d24 1 QC3.53 [2.33, 4.56]2.50-2.34 [-3.47, -1.25]4.35 [2.95, 5.34]17% [0%, 35%]25%50%+0.28+0.492026-08-07 → 2026-08-30
tmax12Znearest90d24 1 QC3.53 [2.02, 4.66]2.50-2.34 [-3.76, -1.17]4.35 [2.56, 5.42]17% [0%, 39%]25%50%+0.28+0.492026-08-07 → 2026-08-30
tmax12Znearest365d24 1 QC3.53 [2.03, 4.81]2.50-2.34 [-3.81, -1.28]4.35 [2.61, 5.53]17% [0%, 38%]25%50%+0.28+0.492026-08-07 → 2026-08-30
tmax12Znearestall24 1 QC3.53 [2.10, 4.76]2.50-2.34 [-3.61, -1.18]4.35 [2.62, 5.47]17% [0%, 39%]25%50%+0.28+0.492026-08-07 → 2026-08-30
tmin00Zbilinear30d24 1 QC3.03 [2.48, 3.67]3.01+0.48 [-1.41, 2.23]3.63 [3.02, 4.24]17% [5%, 26%]38%50%+0.30+0.292026-08-07 → 2026-08-30
tmin00Zbilinear90d24 1 QC3.03 [2.51, 3.75]3.01+0.48 [-1.87, 2.67]3.63 [3.02, 4.28]17% [0%, 26%]38%50%+0.30+0.292026-08-07 → 2026-08-30
tmin00Zbilinear365d24 1 QC3.03 [2.37, 3.78]3.01+0.48 [-2.24, 2.58]3.63 [2.88, 4.34]17% [0%, 29%]38%50%+0.30+0.292026-08-07 → 2026-08-30
tmin00Zbilinearall24 1 QC3.03 [2.38, 3.81]3.01+0.48 [-2.20, 2.68]3.63 [2.92, 4.38]17% [0%, 29%]38%50%+0.30+0.292026-08-07 → 2026-08-30
tmin00Znearest30d24 1 QC3.07 [2.46, 3.74]3.03+0.77 [-1.13, 2.53]3.69 [2.99, 4.37]12% [0%, 24%]42%54%+0.29+0.292026-08-07 → 2026-08-30
tmin00Znearest90d24 1 QC3.07 [2.48, 3.83]3.03+0.77 [-1.58, 2.96]3.69 [2.97, 4.37]12% [0%, 24%]42%54%+0.29+0.292026-08-07 → 2026-08-30
tmin00Znearest365d24 1 QC3.07 [2.34, 3.85]3.03+0.77 [-1.93, 2.90]3.69 [2.83, 4.41]12% [0%, 25%]42%54%+0.29+0.292026-08-07 → 2026-08-30
tmin00Znearestall24 1 QC3.07 [2.35, 3.92]3.03+0.77 [-1.92, 3.00]3.69 [2.88, 4.48]12% [0%, 24%]42%54%+0.29+0.292026-08-07 → 2026-08-30
tmin12Zbilinear30d24 1 QC3.01 [2.24, 3.73]3.01+0.19 [-1.65, 2.10]3.74 [2.71, 4.55]21% [10%, 33%]42%54%+0.31+0.292026-08-07 → 2026-08-30
tmin12Zbilinear90d24 1 QC3.01 [2.03, 3.83]3.01+0.19 [-1.78, 2.47]3.74 [2.48, 4.61]21% [10%, 35%]42%54%+0.31+0.292026-08-07 → 2026-08-30
tmin12Zbilinear365d24 1 QC3.01 [1.92, 3.83]3.01+0.19 [-1.80, 2.52]3.74 [2.30, 4.68]21% [9%, 36%]42%54%+0.31+0.292026-08-07 → 2026-08-30
tmin12Zbilinearall24 1 QC3.01 [2.02, 3.74]3.01+0.19 [-1.95, 2.55]3.74 [2.41, 4.60]21% [9%, 36%]42%54%+0.31+0.292026-08-07 → 2026-08-30
tmin12Znearest30d24 1 QC2.99 [2.14, 3.75]3.01+0.52 [-1.30, 2.45]3.76 [2.61, 4.64]25% [13%, 40%]42%58%+0.31+0.292026-08-07 → 2026-08-30
tmin12Znearest90d24 1 QC2.99 [1.97, 3.83]3.01+0.52 [-1.44, 2.78]3.76 [2.35, 4.71]25% [12%, 42%]42%58%+0.31+0.292026-08-07 → 2026-08-30
tmin12Znearest365d24 1 QC2.99 [1.83, 3.84]3.01+0.52 [-1.48, 2.85]3.76 [2.12, 4.80]25% [13%, 43%]42%58%+0.31+0.292026-08-07 → 2026-08-30
tmin12Znearestall24 1 QC2.99 [1.91, 3.81]3.01+0.52 [-1.62, 2.88]3.76 [2.24, 4.78]25% [12%, 43%]42%58%+0.31+0.292026-08-07 → 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 AIFS Single at KDCA, lead day 6, 00Z bilinear tmax+20+100-10-202026-08-07: -1.4 °F2026-08-08: -0.59 °F2026-08-09: -1.46 °F2026-08-10: +1.37 °F2026-08-11: -1.09 °F2026-08-12: -1.81 °F2026-08-13: -1.55 °F2026-08-14: +0.16 °F2026-08-15: -8 °F2026-08-16: -3.3 °F2026-08-17: -4.66 °F2026-08-18: -4.29 °F2026-08-19: -3.27 °F2026-08-20: -5.69 °F2026-08-21: -6.86 °F2026-08-22: +6.12 °F2026-08-23: -2.79 °F2026-08-24: -5.72 °F2026-08-25: -3.72 °F2026-08-26: -2.64 °F2026-08-27: -11.88 °F2026-08-28: -6.56 °F2026-08-29: -1.32 °F2026-08-30: -4.72 °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
2026-08-30-4.72
2026-08-29-1.32
2026-08-28-6.56
2026-08-27-11.88
2026-08-26-2.64
2026-08-25-3.72
2026-08-24-5.72
2026-08-23-2.79
2026-08-22+6.12
2026-08-21-6.86
2026-08-20-5.69
2026-08-19-3.27
2026-08-18-4.29
2026-08-17-4.66
2026-08-16-3.30
2026-08-15-8.00
2026-08-14+0.16
2026-08-13-1.55
2026-08-12-1.81
2026-08-11-1.09
2026-08-10+1.37
2026-08-09-1.46
2026-08-08-0.59
2026-08-07-1.40

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single 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: 1 day-10 to -8 °F: 1 day-8 to -6 °F: 2 days-6 to -4 °F: 5 days-4 to -2 °F: 5 days-2 to 0 °F: 7 days0 to 2 °F: 2 days2 to 4 °F: 0 days4 to 6 °F: 0 days6 to 8 °F: 1 day8 to 10 °F: 0 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 3.29 · P90 |e| 6.77 °F-200+20 °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
-20.00-18.000
-18.00-16.000
-16.00-14.000
-14.00-12.000
-12.00-10.001
-10.00-8.001
-8.00-6.002
-6.00-4.005
-4.00-2.005
-2.00+0.007
+0.00+2.002
+2.00+4.000
+4.00+6.000
+6.00+8.001
+8.00+10.000
+10.00+12.000
+12.00+14.000
+14.00+16.000
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08243.79 -3.15

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
NCEP GFS 24 +0.20 [-2.74, 2.41] no
GraphCast (IFS init) 24 -1.22 [-2.95, -0.18] yes
ECMWF IFS HRES 19 -0.25 [-2.15, 0.88] no
Persistence (baseline) 24 -1.08 [-2.87, 0.35] no

Cite this page

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

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