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 1088

The ledger, through September 15

Mean absolute temperature error runs 2.23°F at day 1 and 3.61°F at day 7, over 415,341 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 16–September 15, 2026.

LeadNDFDNBMpairs
Day 12.292.2364,411
Day 22.482.4362,154
Day 32.742.6559,655
Day 42.972.8657,300
Day 53.223.1154,905
Day 63.483.3752,494
Day 73.773.6140,726
Day 83.9123,696

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 31,975
August 16–September 15, 2026
day-3 mean absolute temperature error, NBM
Forecast Network verification ledger
2.65 °F of 29,632
August 16–September 15, 2026
day-5 mean absolute temperature error, NBM
Forecast Network verification ledger
3.11 °F of 27,308
August 16–September 15, 2026
day-7 mean absolute temperature error, NBM
Forecast Network verification ledger
3.61 °F of 24,895
August 16–September 15, 2026
day-1 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.29 °F of 32,436
August 16–September 15, 2026
day-3 mean absolute temperature error, NDFD
Forecast Network verification ledger
2.74 °F of 30,023
August 16–September 15, 2026
day-5 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.22 °F of 27,597
August 16–September 15, 2026
day-7 mean absolute temperature error, NDFD
Forecast Network verification ledger
3.77 °F of 15,831
August 16–September 15, 2026
Milepost
1088 · laid 2026-09-15T00:25:13Z
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
00232d726529b554ceabd9fbe57d615e356bc405924ab614d2803a8ff3bf7a46
Machine
JSON