The algorithm's predicted chance of seeing firesky over NYC at sunset. Discrete values (20 / 40 / 50 / 75 / 90) from a decision tree. ≥75% means "expected to occur".
Quality /10
The visual quality of the firesky when it occurs. Q=10 is intensely vivid; Q=4 means muted colors even when present. Only meaningful when probability ≥ 50% — if the sky is overcast anyway, Q has no use.
Ground truth
The photo source determines what actually happened each day: ★ green firesky captured on camera (72 days) unmarked monitored, no firesky (67 days)
EarthCam Empire State Building / NY Harbor feeds serve as objective evidence.
Confusion matrix
TP algo says yes + actually yes ✓ FN algo says no + actually yes (missed prediction — worst case) FP algo says yes + actually no (false alarm — wasted wait) TN algo says no + actually no ✓
At ≥75% threshold → 87.1% accuracy.
Accuracy = (TP+TN) / total. Fraction of all calls that were correct.Recall = TP / (TP+FN). Of days that truly had firesky, what fraction the algo caught (avoids misses).Precision = TP / (TP+FP). Of days the algo said "yes", what fraction were actually firesky (avoids false alarms).F1 = harmonic mean of Recall and Precision. Single balanced score — closer to 1.0 is better.