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

Washington Reagan · ECMWF AIFS Single · lead day 2

KDCA · aifs_single · lead 2

Target day = initialization date + 2 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
tmax00Zbilinear30d28 1 QC2.57 [1.72, 3.46]1.83-2.11 [-3.42, -0.72]3.13 [2.12, 4.07]21% [7%, 37%]50%64%+0.24+0.462026-08-03 → 2026-08-30
tmax00Zbilinear90d28 1 QC2.57 [1.69, 3.59]1.83-2.11 [-3.54, -0.71]3.13 [2.05, 4.18]21% [5%, 40%]50%64%+0.24+0.462026-08-03 → 2026-08-30
tmax00Zbilinear365d28 1 QC2.57 [1.57, 3.68]1.83-2.11 [-3.65, -0.48]3.13 [1.90, 4.26]21% [0%, 41%]50%64%+0.24+0.462026-08-03 → 2026-08-30
tmax00Zbilinearall28 1 QC2.57 [1.65, 3.68]1.83-2.11 [-3.67, -0.66]3.13 [2.00, 4.19]21% [0%, 40%]50%64%+0.24+0.462026-08-03 → 2026-08-30
tmax00Znearest30d28 1 QC2.45 [1.68, 3.29]1.90-1.91 [-3.23, -0.44]3.02 [2.07, 3.90]21% [10%, 31%]46%68%+0.28+0.442026-08-03 → 2026-08-30
tmax00Znearest90d28 1 QC2.45 [1.65, 3.42]1.90-1.91 [-3.36, -0.44]3.02 [2.01, 4.02]21% [8%, 33%]46%68%+0.28+0.442026-08-03 → 2026-08-30
tmax00Znearest365d28 1 QC2.45 [1.54, 3.56]1.90-1.91 [-3.48, -0.22]3.02 [1.86, 4.11]21% [7%, 33%]46%68%+0.28+0.442026-08-03 → 2026-08-30
tmax00Znearestall28 1 QC2.45 [1.59, 3.54]1.90-1.91 [-3.52, -0.41]3.02 [1.94, 4.05]21% [7%, 33%]46%68%+0.28+0.442026-08-03 → 2026-08-30
tmax12Zbilinear30d28 1 QC2.69 [1.74, 3.78]1.84-2.28 [-3.74, -0.89]3.37 [2.07, 4.60]14% [0%, 32%]50%68%+0.21+0.462026-08-03 → 2026-08-30
tmax12Zbilinear90d28 1 QC2.69 [1.67, 3.94]1.84-2.28 [-3.93, -0.80]3.37 [1.95, 4.74]14% [0%, 32%]50%68%+0.21+0.462026-08-03 → 2026-08-30
tmax12Zbilinear365d28 1 QC2.69 [1.58, 4.02]1.84-2.28 [-3.99, -0.62]3.37 [1.85, 4.77]14% [0%, 33%]50%68%+0.21+0.462026-08-03 → 2026-08-30
tmax12Zbilinearall28 1 QC2.69 [1.68, 4.08]1.84-2.28 [-4.08, -0.67]3.37 [1.93, 4.82]14% [0%, 33%]50%68%+0.21+0.462026-08-03 → 2026-08-30
tmax12Znearest30d28 1 QC2.55 [1.62, 3.61]1.89-2.08 [-3.54, -0.66]3.26 [2.01, 4.44]18% [4%, 31%]50%68%+0.25+0.442026-08-03 → 2026-08-30
tmax12Znearest90d28 1 QC2.55 [1.59, 3.77]1.89-2.08 [-3.76, -0.55]3.26 [1.89, 4.57]18% [4%, 29%]50%68%+0.25+0.442026-08-03 → 2026-08-30
tmax12Znearest365d28 1 QC2.55 [1.50, 3.84]1.89-2.08 [-3.82, -0.38]3.26 [1.81, 4.59]18% [0%, 32%]50%68%+0.25+0.442026-08-03 → 2026-08-30
tmax12Znearestall28 1 QC2.55 [1.58, 3.87]1.89-2.08 [-3.87, -0.41]3.26 [1.86, 4.64]18% [0%, 30%]50%68%+0.25+0.442026-08-03 → 2026-08-30
tmin00Zbilinear30d28 1 QC1.89 [1.47, 2.31]1.89+0.47 [-0.68, 1.49]2.39 [1.83, 2.87]36% [23%, 50%]68%79%+0.44+0.442026-08-03 → 2026-08-30
tmin00Zbilinear90d28 1 QC1.89 [1.43, 2.33]1.89+0.47 [-0.85, 1.63]2.39 [1.74, 2.87]36% [22%, 48%]68%79%+0.44+0.442026-08-03 → 2026-08-30
tmin00Zbilinear365d28 1 QC1.89 [1.43, 2.32]1.89+0.47 [-1.09, 1.66]2.39 [1.73, 2.86]36% [23%, 50%]68%79%+0.44+0.442026-08-03 → 2026-08-30
tmin00Zbilinearall28 1 QC1.89 [1.33, 2.37]1.89+0.47 [-0.94, 1.66]2.39 [1.65, 2.92]36% [22%, 50%]68%79%+0.44+0.442026-08-03 → 2026-08-30
tmin00Znearest30d28 1 QC1.92 [1.45, 2.37]1.91+0.75 [-0.42, 1.79]2.46 [1.82, 2.95]29% [17%, 42%]68%79%+0.43+0.442026-08-03 → 2026-08-30
tmin00Znearest90d28 1 QC1.92 [1.39, 2.45]1.91+0.75 [-0.59, 1.90]2.46 [1.73, 2.99]29% [14%, 44%]68%79%+0.43+0.442026-08-03 → 2026-08-30
tmin00Znearest365d28 1 QC1.92 [1.40, 2.40]1.91+0.75 [-0.83, 1.95]2.46 [1.73, 2.98]29% [14%, 44%]68%79%+0.43+0.442026-08-03 → 2026-08-30
tmin00Znearestall28 1 QC1.92 [1.31, 2.43]1.91+0.75 [-0.68, 1.95]2.46 [1.64, 3.03]29% [14%, 47%]68%79%+0.43+0.442026-08-03 → 2026-08-30
tmin12Zbilinear30d28 1 QC1.70 [1.23, 2.10]1.67+0.73 [-0.38, 1.68]2.22 [1.58, 2.66]39% [23%, 56%]68%82%+0.50+0.512026-08-03 → 2026-08-30
tmin12Zbilinear90d28 1 QC1.70 [1.17, 2.15]1.67+0.73 [-0.57, 1.78]2.22 [1.52, 2.69]39% [23%, 60%]68%82%+0.50+0.512026-08-03 → 2026-08-30
tmin12Zbilinear365d28 1 QC1.70 [1.15, 2.14]1.67+0.73 [-0.87, 1.82]2.22 [1.53, 2.68]39% [21%, 60%]68%82%+0.50+0.512026-08-03 → 2026-08-30
tmin12Zbilinearall28 1 QC1.70 [1.13, 2.14]1.67+0.73 [-0.64, 1.78]2.22 [1.46, 2.68]39% [21%, 62%]68%82%+0.50+0.512026-08-03 → 2026-08-30
tmin12Znearest30d28 1 QC1.78 [1.22, 2.27]1.68+0.99 [-0.13, 1.96]2.33 [1.57, 2.83]39% [17%, 62%]64%82%+0.48+0.502026-08-03 → 2026-08-30
tmin12Znearest90d28 1 QC1.78 [1.14, 2.33]1.68+0.99 [-0.30, 2.07]2.33 [1.52, 2.87]39% [17%, 67%]64%82%+0.48+0.502026-08-03 → 2026-08-30
tmin12Znearest365d28 1 QC1.78 [1.06, 2.31]1.68+0.99 [-0.60, 2.09]2.33 [1.46, 2.87]39% [14%, 70%]64%82%+0.48+0.502026-08-03 → 2026-08-30
tmin12Znearestall28 1 QC1.78 [1.05, 2.32]1.68+0.99 [-0.38, 2.05]2.33 [1.44, 2.88]39% [17%, 69%]64%82%+0.48+0.502026-08-03 → 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 2, 00Z bilinear tmax+10+50-5-102026-08-03: -3.75 °F2026-08-04: -4.08 °F2026-08-05: -4.79 °F2026-08-06: +0.55 °F2026-08-07: -1.84 °F2026-08-08: -0.72 °F2026-08-09: -1.47 °F2026-08-10: +0.69 °F2026-08-11: +1.76 °F2026-08-12: -0.69 °F2026-08-13: +1.28 °F2026-08-14: +2.09 °F2026-08-15: -0.43 °F2026-08-16: -1.69 °F2026-08-17: -4.2 °F2026-08-18: -1.62 °F2026-08-19: -2.75 °F2026-08-20: -8.55 °F2026-08-21: -5.15 °F2026-08-22: -1.91 °F2026-08-23: -3.9 °F2026-08-24: -3.18 °F2026-08-25: -3.6 °F2026-08-26: -1.04 °F2026-08-27: -2.48 °F2026-08-28: -3.9 °F2026-08-29: -0.94 °F2026-08-30: -2.79 °F2026-08-032026-08-30°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 (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.79
2026-08-29-0.94
2026-08-28-3.90
2026-08-27-2.48
2026-08-26-1.04
2026-08-25-3.60
2026-08-24-3.18
2026-08-23-3.90
2026-08-22-1.91
2026-08-21-5.15
2026-08-20-8.55
2026-08-19-2.75
2026-08-18-1.62
2026-08-17-4.20
2026-08-16-1.69
2026-08-15-0.43
2026-08-14+2.09
2026-08-13+1.28
2026-08-12-0.69
2026-08-11+1.76
2026-08-10+0.69
2026-08-09-1.47
2026-08-08-0.72
2026-08-07-1.84
2026-08-06+0.55
2026-08-05-4.79
2026-08-04-4.08
2026-08-03-3.75

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KDCA, lead day 2-10 to -9 °F: 0 days-9 to -8 °F: 1 day-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 1 day-5 to -4 °F: 3 days-4 to -3 °F: 5 days-3 to -2 °F: 3 days-2 to -1 °F: 6 days-1 to 0 °F: 4 days0 to 1 °F: 2 days1 to 2 °F: 2 days2 to 3 °F: 1 day3 to 4 °F: 0 days4 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 · P90 |e| 4.37 °F-100+10 °Fn = 28 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
-9.00-8.001
-8.00-7.000
-7.00-6.000
-6.00-5.001
-5.00-4.003
-4.00-3.005
-3.00-2.003
-2.00-1.006
-1.00+0.004
+0.00+1.002
+1.00+2.002
+2.00+3.001
+3.00+4.000
+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
2026-08282.57 -2.11

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28

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
Aurora (IFS init) 1 -4.97 [-4.97, -4.97] yes
FourCastNet v2 (IFS init) 1 -0.11 [-0.11, -0.11] yes
NCEP GFS 28 -0.43 [-1.15, 0.28] no
GraphCast (IFS init) 26 -2.20 [-2.81, -1.72] yes
ECMWF IFS HRES 22 -1.41 [-2.72, -0.44] yes
Pangu-Weather (IFS init) 1 -0.91 [-0.91, -0.91] yes
Persistence (baseline) 28 -0.83 [-1.70, 0.52] no

Cite this page

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

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

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