Schedule: the flights that flew on Friday, Oct 23, re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.
SKYWEST · FLIGHT OO 3991
SCHEDULED · TYPICAL SCHEDULE
Friday, October 30
OO 3991 · SEA → SFO
departs 5:50 PM PT · arrives 8:16 PM PT
Forecast issued Thu 1:00 AM ET · 44h before departure
Watch this flight
Other days
Today 30%
Fri 10/30
Sun 11/1 50%
Mon 11/2 38%
Tue 11/3 32%
Wed 11/4 43%
Odds over time
Arrive at SFO more than 15 minutes late?
32%
chance · ±2 pts
+0 pts · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
32%
Leave 15+ late
28%
Arrive 1h+ late
13%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
6.9d
Now
1d
12h
6h
Departs
Lands
Arrive at SFO more than 15 minutes late?
Calm-weather odds: 22% · changed +0 pts in 24h
+0 pts
32%
Yes 32%
No 68%
Leave SEA more than 15 minutes late?
Calm-weather odds: 22% · changed +1 pt in 24h
+1 pt
28%
Yes 28%
No 72%
Arrive at SFO more than an hour late?
Calm-weather odds: 8% · changed +0 pts in 24h
+0 pts
13%
Yes 13%
No 87%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to SFO?
On time or early
68%
15–30 min late
11%
30 min–1 hour late
7%
1–2 hours late
6%
Over 2 hours late
7%
Cancelled
<1%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.
What’s moving the odds
↑
This flight has been late 33% of the time recently
↑
Arrivals into SFO at that hour are often late
↑
SFO is prone to delays
↓
Mostly benign weather forecast at SFO
↓
Other factors
Weather at each end
SEA (origin)
Gusts 5 kt Ceiling 4,000 ft Visibility 10+ mi Precip 0.01 in
SFO (destination)
Gusts 16 kt Ceiling 4,500 ft Visibility 10+ mi Precip none
How this resolves
Yes if the gate arrival is more than 15 minutes after the scheduled arrival. Cancelled or diverted flights resolve N/A.
Every question here is display only — there is no betting or money involved. Gate times come from the airline; a cancellation resolves only the “Cancelled?” question, and a diversion voids the delay questions.