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 1048

The ledger, through September 11

Mean absolute temperature error runs 2.22°F at day 1 and 3.40°F at day 7, over 345,156 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 12–September 11, 2026.

LeadNDFDNBMpairs
Day 12.272.2254,803
Day 22.452.4152,546
Day 32.692.6050,122
Day 42.872.7847,692
Day 53.102.9845,297
Day 63.333.2142,886
Day 73.583.4032,918
Day 83.6718,892

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 27,171
August 12–September 11, 2026
day-3 mean absolute temperature error, NBM
Forecast Network verification ledger
2.6 °F of 24,903
August 12–September 11, 2026
day-5 mean absolute temperature error, NBM
Forecast Network verification ledger
2.98 °F of 22,504
August 12–September 11, 2026
day-7 mean absolute temperature error, NBM
Forecast Network verification ledger
3.4 °F of 20,091
August 12–September 11, 2026
day-1 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.27 °F of 27,632
August 12–September 11, 2026
day-3 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.69 °F of 25,219
August 12–September 11, 2026
day-5 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.1 °F of 22,793
August 12–September 11, 2026
day-7 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.58 °F of 12,827
August 12–September 11, 2026
Milepost
1048 · laid 2026-09-11T00:25:12Z
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
2e479b5784b3479fb47366d0ec954cbed4b74c3b14b3ec300d83b0a55d736586
Machine
JSON