7-day fog outlook · Grayslake / Lake County

7-day fog outlook — Grayslake / Lake County

dashboard · tonight · 7-day outlook · region: Grayslake / Lake County

run 2026-10-16T00:24-05:00 · home point 42.3434, -88.0412

Set-up score = the same factor blend the day-1 report uses, before calibration. It ranks mornings; it is not a probability. Day 1 is calibrated in the main report. ★ = best-ranked morning beyond tomorrow.

morning	set-up	band	type	light	T−Td min	wind	mid+high cloud	sunrise	models
Fri 16 Oct	0.06	poor	shallow ground fog	filtered sun	2.1 °C	11.6 kt	29 %	07:06 · 101.5°	5 (HRRR primary), spread 0.07
Sat 17 Oct	0.46	marginal	shallow ground fog	sun will reach the fog top	2.0 °C	5.8 kt	0 %	07:07 · 102.0°	5 (HRRR primary), spread 0.48
Sun 18 Oct	0.28	poor	shallow ground fog	sun will reach the fog top	5.8 °C	8.3 kt	0 %	07:08 · 102.5°	4 (ECMWF primary), spread 0.40
Mon 19 Oct	0.54	marginal	shallow ground fog	sun will reach the fog top	2.7 °C	4.7 kt	0 %	07:10 · 103.0°	4 (ECMWF primary), spread 0.59
Tue 20 Oct	0.43	poor	shallow ground fog	overcast above the fog	2.2 °C	2.4 kt	91 %	07:11 · 103.5°	4 (ECMWF primary), spread 0.71
Wed 21 Oct ★	0.62	decent set-up	shallow ground fog	sun will reach the fog top	1.1 °C	3.0 kt	1 %	07:12 · 103.9°	4 (ECMWF primary), spread 0.80
Thu 22 Oct	0.53	marginal	shallow ground fog	filtered sun	1.5 °C	3.1 kt	33 %	07:13 · 104.4°	4 (ECMWF primary), spread 0.56

What a set-up score has meant (day-1 backtest, raw score before calibration, airport mornings)

strong set-up (≥ 0.75): fog on 25 % of 44 mornings
decent set-up (≥ 0.60): fog on 17 % of 82 mornings
marginal (≥ 0.45): fog on 12 % of 154 mornings
poor (≥ 0.00): fog on 8 % of 285 mornings

Ranking skill by lead (AUC from the lead backtest; 0.5 = none, 1 = perfect): 1 day ahead 0.746, 2 days ahead 0.726, 3 days ahead 0.738, 5 days ahead 0.627

Fri 16 Oct — set-up 0.06, poor

Confidencesee the main report (calibrated, HRRR included)Typeshallow ground fogLightfiltered sunSunrise07:06 at 101.5° ESEHours saturated0Per modelgfs_hrrr 0.05, ecmwf_ifs025 0.068, gfs_global 0.031, icon_seamless 0.033, ncep_nbm_conus 0.103

Sat 17 Oct — set-up 0.46, marginal

ConfidenceHRRR reaches this morning; models usually agree on the airmass; backtest AUC at this lead 0.726 (measured at 2 days)Typeshallow ground fogLightsun will reach the fog topSunrise07:07 at 102.0° ESEHours saturated0Per modelgfs_hrrr 0.519, ecmwf_ifs025 0.492, gfs_global 0.395, icon_seamless 0.1, ncep_nbm_conus 0.581

Sun 18 Oct — set-up 0.28, poor

Confidenceset-up only: dewpoint, wind and sky from the global models; backtest AUC at this lead 0.738 (measured at 3 days)Typeshallow ground fogLightsun will reach the fog topSunrise07:08 at 102.5° ESEHours saturated0Per modelgfs_hrrr None, ecmwf_ifs025 0.091, gfs_global 0.088, icon_seamless 0.483, ncep_nbm_conus 0.429

Mon 19 Oct — set-up 0.54, marginal

Confidenceset-up only: dewpoint, wind and sky from the global models; backtest AUC at this lead 0.738 (measured at 3 days)Typeshallow ground fogLightsun will reach the fog topSunrise07:10 at 103.0° ESEHours saturated0Per modelgfs_hrrr None, ecmwf_ifs025 0.606, gfs_global 0.118, icon_seamless 0.709, ncep_nbm_conus 0.624

Tue 20 Oct — set-up 0.43, poor

Confidencepattern only; expect the number to move; backtest AUC at this lead 0.627 (measured at 5 days)Typeshallow ground fogLightovercast above the fogSunrise07:11 at 103.5° ESEHours saturated0Per modelgfs_hrrr None, ecmwf_ifs025 0.479, gfs_global 0.092, icon_seamless 0.101, ncep_nbm_conus 0.806

Wed 21 Oct — set-up 0.62, decent set-up

Confidencepattern only; expect the number to move; backtest AUC at this lead 0.627 (measured at 5 days)Typeshallow ground fogLightsun will reach the fog topSunrise07:12 at 103.9° ESEHours saturated0Per modelgfs_hrrr None, ecmwf_ifs025 0.798, gfs_global 0.09, icon_seamless 0.487, ncep_nbm_conus 0.891

Thu 22 Oct — set-up 0.53, marginal

Confidencepattern only; expect the number to move; backtest AUC at this lead 0.627 (measured at 5 days)Typeshallow ground fogLightfiltered sunSunrise07:13 at 104.4° ESEHours saturated0Per modelgfs_hrrr None, ecmwf_ifs025 0.679, gfs_global 0.114, icon_seamless 0.603, ncep_nbm_conus 0.607

Honesty notes

Days 2–7 use ECMWF, GFS, ICON and NBM (HRRR where its 48 h reach allows). The set-up score is the raw factor blend; it ranks mornings and is not a calibrated probability.
Skill falls with lead. Use days 5–7 only to spot a pattern; re-check nightly and treat the day-1 report as the decision.
No vertical profile, river gauge or NBM bulletin feeds the outlook; those are day-1 checks only.