Edition 2026-09-16 The Ledger Archive API RSS Weather Trader
Milepost
1108

TheForecast Post

A chronicle of American weather and climate  ·  Wednesday, 16 September 2026

The Ledger The Ledger MILEPOST 1058

The ledger, through September 12

Mean absolute temperature error runs 2.22°F at day 1 and 3.48°F at day 7, over 362,764 settled forecast-observation pairs.

Every forecast this network publishes for a station with an ASOS report is compared against that report once the valid time has passed, and the residual is written down. This is the standing table for August 13–September 12, 2026.

LeadNDFDNBMpairs
Day 12.272.2257,211
Day 22.462.4154,954
Day 32.692.6152,530
Day 42.882.7950,100
Day 53.123.0147,705
Day 63.383.2545,294
Day 73.663.4834,874
Day 83.7520,096

Mean absolute error, °F, temperature. ASOS reports at :53 and the forecast is stamped on the hour, so a forecast is paired with the nearest observation within 30 minutes and otherwise left unscored.

The numbers in this piece, with what they are measured against
day-1 mean absolute temperature error, NBM
Forecast Network verification ledger
2.22 °F of 28,375
August 13–September 12, 2026
day-3 mean absolute temperature error, NBM
Forecast Network verification ledger
2.61 °F of 26,107
August 13–September 12, 2026
day-5 mean absolute temperature error, NBM
Forecast Network verification ledger
3.01 °F of 23,708
August 13–September 12, 2026
day-7 mean absolute temperature error, NBM
Forecast Network verification ledger
3.48 °F of 21,295
August 13–September 12, 2026
day-1 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.27 °F of 28,836
August 13–September 12, 2026
day-3 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.69 °F of 26,423
August 13–September 12, 2026
day-5 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.12 °F of 23,997
August 13–September 12, 2026
day-7 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.66 °F of 13,579
August 13–September 12, 2026
Milepost
1058 · laid 2026-09-12T00:25:11Z
Desk
ledger v1
Method
ASOS reports at :53 and the forecast is stamped on the hour, so a forecast is paired with the nearest observation within 30 minutes and otherwise left unscored.
Source
/home/maue/forecastpoints/data/verify/2026-08.ndjson
/home/maue/forecastpoints/data/verify/2026-09.ndjson
Digest
6ff60e816be622d2549a4efc9e3c00285eda13a58ee6d2bd68efb096ad8d77ec
Machine
JSON