KSTL / Wed Oct 21 / OFFICIAL STATION RECORD

St. Louis, MOHigh ≥ 78°F

CONSENSUS FORECAST27%Oct 17 · 03:55 UTC

THE FORECAST FIELD

Who takes which side?

0% · NO50%YES · 100%

48%

35%

30%

18%

Consensus

27%

Probabilities derived from each source’s mean and spread. Forecasts may have different initialization times.

HOW A MODEL CONTRACT WORKS

Head-to-head preview

ILLUSTRATIVE · NOT EXECUTED

AIFSYES 27.7¢Risks 27.75u

EPSNO 72.2¢Risks 72.25u

100 contracts at the midpoint of these model probabilities. Each contract pays 1u to the winning side.

AIFS +72.25u · EPS −72.25u

These are current forecast comparisons, not locked entries. No credits have been committed. Read the proposed policy →

FOLLOW THE RUNS

Probability history

Recorded Reconstructed

Reconstructed from archived summary forecasts using a shared lead-dependent Gaussian error model. Times are initializations, not verified release times.

AIFS SingleICONGFSUKMETGEMIFS archive

Inspect a forecast 2026-10-20T06:00:00+00:00 · UTC

View the forecast data

UTC	AIFS	ICON	GFS	UKMET	GEM	IFS*
2026-10-06T12:00:00+00:00	0.0%	—	—	—	—	0.2%
2026-10-06T18:00:00+00:00	46.3%	—	—	—	—	—
2026-10-07T00:00:00+00:00	0.2%	—	—	—	—	10.0%
2026-10-07T06:00:00+00:00	1.0%	—	—	—	—	—
2026-10-07T12:00:00+00:00	7.1%	—	—	—	—	9.8%
2026-10-07T18:00:00+00:00	0.1%	—	—	—	—	—
2026-10-08T00:00:00+00:00	0.4%	—	—	—	—	5.3%
2026-10-08T06:00:00+00:00	23.2%	—	—	—	—	—
2026-10-08T12:00:00+00:00	13.7%	—	—	—	—	14.9%
2026-10-08T18:00:00+00:00	10.5%	—	—	—	—	—
2026-10-09T00:00:00+00:00	12.3%	—	—	—	—	14.9%
2026-10-09T06:00:00+00:00	8.7%	—	—	—	—	—
2026-10-09T12:00:00+00:00	14.6%	—	—	—	—	20.1%
2026-10-09T18:00:00+00:00	41.0%	—	—	—	—	—
2026-10-10T00:00:00+00:00	41.5%	—	—	—	—	24.4%
2026-10-10T06:00:00+00:00	28.3%	—	—	—	—	—
2026-10-10T12:00:00+00:00	41.0%	—	—	—	—	28.7%
2026-10-10T18:00:00+00:00	27.5%	—	—	—	—	—
2026-10-11T00:00:00+00:00	41.3%	—	—	—	—	28.1%
2026-10-11T06:00:00+00:00	50.6%	—	20.8%	—	—	—
2026-10-11T12:00:00+00:00	10.0%	—	—	—	—	28.4%
2026-10-11T18:00:00+00:00	14.9%	—	—	—	—	—
2026-10-12T00:00:00+00:00	8.3%	—	1.3%	—	—	34.0%
2026-10-12T06:00:00+00:00	5.7%	—	63.4%	—	—	—
2026-10-12T12:00:00+00:00	18.1%	—	—	—	—	27.7%
2026-10-12T18:00:00+00:00	8.9%	—	—	—	—	—
2026-10-13T00:00:00+00:00	5.4%	—	—	—	—	32.4%
2026-10-13T06:00:00+00:00	19.3%	—	9.4%	—	—	—
2026-10-13T12:00:00+00:00	9.3%	—	7.5%	—	—	25.7%
2026-10-13T18:00:00+00:00	48.0%	—	44.0%	—	—	—
2026-10-14T00:00:00+00:00	52.7%	1.8%	11.1%	—	—	20.8%
2026-10-14T06:00:00+00:00	46.6%	—	77.6%	—	—	—
2026-10-14T12:00:00+00:00	24.6%	16.6%	47.2%	0.2%	—	8.5%
2026-10-14T18:00:00+00:00	28.9%	—	50.7%	—	—	—
2026-10-15T00:00:00+00:00	31.0%	17.0%	37.8%	2.2%	—	12.0%
2026-10-15T06:00:00+00:00	38.9%	—	38.9%	—	—	—
2026-10-15T12:00:00+00:00	27.7%	22.8%	32.3%	6.8%	—	12.5%
2026-10-15T18:00:00+00:00	24.1%	—	33.4%	—	—	—
2026-10-16T00:00:00+00:00	27.4%	16.9%	25.5%	9.7%	—	6.7%
2026-10-16T06:00:00+00:00	23.7%	—	17.3%	—	—	—
2026-10-16T12:00:00+00:00	18.9%	11.2%	27.9%	8.0%	—	10.1%
2026-10-16T18:00:00+00:00	22.0%	1.5%	26.0%	—	—	0.0%
2026-10-17T00:00:00+00:00	17.2%	1.7%	28.4%	5.4%	—	5.9%
2026-10-17T06:00:00+00:00	14.0%	3.9%	33.4%	—	—	5.2%
2026-10-17T12:00:00+00:00	12.4%	2.1%	28.2%	2.2%	—	3.8%
2026-10-17T18:00:00+00:00	12.7%	0.9%	25.3%	—	—	3.2%
2026-10-18T00:00:00+00:00	13.1%	3.2%	28.7%	1.6%	—	3.5%
2026-10-18T06:00:00+00:00	9.2%	2.5%	33.5%	—	—	2.0%
2026-10-18T12:00:00+00:00	10.3%	2.1%	30.3%	0.4%	—	1.9%
2026-10-18T18:00:00+00:00	11.6%	2.0%	32.6%	—	—	—
2026-10-19T00:00:00+00:00	12.5%	6.6%	36.1%	1.0%	—	3.5%
2026-10-19T06:00:00+00:00	5.7%	3.1%	37.8%	0.0%	—	1.2%
2026-10-19T12:00:00+00:00	7.2%	3.1%	31.0%	0.1%	0.0%	1.4%
2026-10-19T18:00:00+00:00	10.8%	7.8%	37.0%	0.3%	—	1.9%
2026-10-20T00:00:00+00:00	11.8%	4.3%	37.7%	0.6%	8.5%	3.3%
2026-10-20T06:00:00+00:00	4.3%	—	33.7%	0.7%	—	0.9%

THE MODEL BOX SCORE

Forecasts & evidence

MODEL	YES	MEAN	SPREAD σ	INITIALIZATION UTC	BRIER ↓
NWS forecast	54%	78.0°F	5.2°F	2026-10-16 14:00	Pending
AIFS Single	48%	77.2°F	5.0°F	2026-10-16 18:00	Pending
National Blend	44%	77.0°F	3.3°F	2026-10-16 06:00	Pending
WeatherNext 2	35%	75.9°F	4.1°F	2026-10-16 12:00	Pending
ICON	30%	74.4°F	6.0°F	2026-10-16 12:00	Pending
IFS HRES	18%	72.1°F	5.8°F	2026-10-16 12:00	Pending
IFS Ensemble	8%	73.4°F	2.9°F	2026-10-16 00:00	Pending

Spread is the standard deviation used in the probability approximation. It is not a measured confidence rating. Brier here scores the latest recorded snapshot, not a league deadline.

SETTLEMENT & PROVENANCE

High ≥ 78°F · KSTL

Daily temperature props settle on the ACIS official station record. Inclusive and strict thresholds retain their exact meanings. Provisional observations do not replace the settlement record.

WP-KSTL-20261021-TMAX-GE78
Opened Oct 14 · 11:20 UTC

Original listing: St. Louis high ≥ 78°F · Wed Oct 21

Original prop, full history & receipt ↗