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 1077

The ledger, through September 14

Mean absolute temperature error runs 2.23°F at day 1 and 3.53°F at day 7, over 397,924 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 15–September 14, 2026.

LeadNDFDNBMpairs
Day 12.292.2362,019
Day 22.482.4359,762
Day 32.722.6357,338
Day 42.912.8254,908
Day 53.153.0452,513
Day 63.413.2950,102
Day 73.713.5338,782
Day 83.8422,500

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 30,779
August 15–September 14, 2026
day-3 mean absolute temperature error, NBM
Forecast Network verification ledger
2.63 °F of 28,511
August 15–September 14, 2026
day-5 mean absolute temperature error, NBM
Forecast Network verification ledger
3.04 °F of 26,112
August 15–September 14, 2026
day-7 mean absolute temperature error, NBM
Forecast Network verification ledger
3.53 °F of 23,699
August 15–September 14, 2026
day-1 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.29 °F of 31,240
August 15–September 14, 2026
day-3 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.72 °F of 28,827
August 15–September 14, 2026
day-5 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.15 °F of 26,401
August 15–September 14, 2026
day-7 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.71 °F of 15,083
August 15–September 14, 2026
Milepost
1077 · laid 2026-09-14T00:25:37Z
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
b4e8a9efa54e3383c4d37c2dcd38d7a854c85ec372cba60c08e16c90d341ad00
Machine
JSON