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 1040

The ledger, through September 10

Mean absolute temperature error runs 2.21°F at day 1 and 3.33°F at day 7, over 327,609 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 11–September 10, 2026.

LeadNDFDNBMpairs
Day 12.272.2152,403
Day 22.452.4050,146
Day 32.682.5947,722
Day 42.852.7645,292
Day 53.072.9642,897
Day 63.273.1640,486
Day 73.523.3330,971
Day 83.6217,692

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
2.21 °F of 25,971
August 11–September 10, 2026
day-3 mean absolute temperature error, NBM
Forecast Network verification ledger
2.59 °F of 23,703
August 11–September 10, 2026
day-5 mean absolute temperature error, NBM
Forecast Network verification ledger
2.96 °F of 21,304
August 11–September 10, 2026
day-7 mean absolute temperature error, NBM
Forecast Network verification ledger
3.33 °F of 18,891
August 11–September 10, 2026
day-1 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.27 °F of 26,432
August 11–September 10, 2026
day-3 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.68 °F of 24,019
August 11–September 10, 2026
day-5 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.07 °F of 21,593
August 11–September 10, 2026
day-7 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.52 °F of 12,080
August 11–September 10, 2026
Milepost
1040 · laid 2026-09-10T12:29:55Z
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
33dbea1eff6ff68fff786d0347c157efdd83a063b00e4efea08292cc84667bbe
Machine
JSON