Edition 2026-09-26 The Ledger Archive API RSS Weather Trader
Milepost
1214

TheForecast Post

A chronicle of American weather and climate  ·  Saturday, 26 September 2026

The Ledger The Ledger MILEPOST 1214

The ledger, through September 26

Mean absolute temperature error runs 2.23°F at day 1 and 3.85°F at day 7, over 513,115 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 27–September 26, 2026.

LeadNDFDNBMpairs
Day 12.292.2370,270
Day 22.512.4470,796
Day 32.772.6670,723
Day 43.012.9070,570
Day 53.333.2069,893
Day 63.663.5469,587
Day 74.053.8556,195
Day 8—4.1635,081

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 34,872
August 27–September 26, 2026
day-3 mean absolute temperature error, NBM
Forecast Network verification ledger
2.66 °F of 35,323
August 27–September 26, 2026
day-5 mean absolute temperature error, NBM
Forecast Network verification ledger
3.2 °F of 35,099
August 27–September 26, 2026
day-7 mean absolute temperature error, NBM
Forecast Network verification ledger
3.85 °F of 35,024
August 27–September 26, 2026
day-1 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.29 °F of 35,398
August 27–September 26, 2026
day-3 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.77 °F of 35,400
August 27–September 26, 2026
day-5 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.33 °F of 34,794
August 27–September 26, 2026
day-7 mean absolute temperature error, NDFD
Forecast Network verification ledger
4.05 °F of 21,171
August 27–September 26, 2026
Milepost
1214 · laid 2026-09-26T00:25:13Z
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
80012b09fc08f4407aea55cdb2580e3ec97a2530418e509b9c94dd8a666f9fde
Machine
JSON