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 1069

The ledger, through September 13

Mean absolute temperature error runs 2.23°F at day 1 and 3.51°F at day 7, over 380,314 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 14–September 13, 2026.

LeadNDFDNBMpairs
Day 12.282.2359,611
Day 22.472.4357,354
Day 32.702.6254,930
Day 42.892.8052,500
Day 53.133.0250,105
Day 63.393.2747,694
Day 73.693.5136,824
Day 83.8121,296

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 29,575
August 14–September 13, 2026
day-3 mean absolute temperature error, NBM
Forecast Network verification ledger
2.62 °F of 27,307
August 14–September 13, 2026
day-5 mean absolute temperature error, NBM
Forecast Network verification ledger
3.02 °F of 24,908
August 14–September 13, 2026
day-7 mean absolute temperature error, NBM
Forecast Network verification ledger
3.51 °F of 22,495
August 14–September 13, 2026
day-1 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.28 °F of 30,036
August 14–September 13, 2026
day-3 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.7 °F of 27,623
August 14–September 13, 2026
day-5 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.13 °F of 25,197
August 14–September 13, 2026
day-7 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.69 °F of 14,329
August 14–September 13, 2026
Milepost
1069 · laid 2026-09-13T00:25:10Z
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
fba3b8a04a436fd829f3600139a27f909860d099f971ea9247e6fc0ef416d7e0
Machine
JSON