Edition 2026-09-23 The Ledger Archive API RSS Weather Trader
Milepost
1182

TheForecast Post

A chronicle of American weather and climate  ·  Wednesday, 23 September 2026

The Ledger The Ledger MILEPOST 1182

The ledger, through September 23

Mean absolute temperature error runs 2.23°F at day 1 and 3.80°F at day 7, over 503,291 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 24–September 23, 2026.

LeadNDFDNBMpairs
Day 12.282.2370,482
Day 22.492.4269,806
Day 32.742.6469,434
Day 42.972.8668,975
Day 53.323.1668,604
Day 63.643.5068,520
Day 73.983.8054,686
Day 84.1032,784

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
2.23 °F of 35,204
August 24–September 23, 2026
day-3 mean absolute temperature error, NBM
Forecast Network verification ledger
2.64 °F of 34,980
August 24–September 23, 2026
day-5 mean absolute temperature error, NBM
Forecast Network verification ledger
3.16 °F of 35,055
August 24–September 23, 2026
day-7 mean absolute temperature error, NBM
Forecast Network verification ledger
3.8 °F of 33,924
August 24–September 23, 2026
day-1 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.28 °F of 35,278
August 24–September 23, 2026
day-3 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.74 °F of 34,454
August 24–September 23, 2026
day-5 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.32 °F of 33,549
August 24–September 23, 2026
day-7 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.98 °F of 20,762
August 24–September 23, 2026
Milepost
1182 · laid 2026-09-23T00:25:14Z
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
3614887ac0bb41c1955b63a973480a9a1557b561e9d6be58e66ec20c7470b509
Machine
JSON