Low ceilings came in sooner than previously forecasted, precluded visual approaches, and forced them on to a single runway operation. The resultant delays were apparently longer than some flights could tolerate, so it was off to the alternate.
Nibog From Ireland, joined Apr 2009, 310 posts, RR: 0 Reply 4, posted (4 years 6 days 9 hours ago) and read 3768 times:
Hi Guys,
I am travelling to SFO next month and I have heard of the fog that rolls in,but I am just curious,are the delays that occured last night the norm under the weather/low ceilings,or was last night a case of mother nature catching everybody out. I fly in on the big EI green bird at 1pm(SFO time) so maybe by that time of the day it may be better!!!.
OPNLguy From , joined Dec 1969, posts, RR: Reply 5, posted (4 years 6 days 8 hours ago) and read 3727 times:
Quoting Nibog (Reply 4):
I am travelling to SFO next month and I have heard of the fog that rolls in,but I am just curious,are the delays that occured last night the norm under the weather/low ceilings,or was last night a case of mother nature catching everybody out. I fly in on the big EI green bird at 1pm(SFO time) so maybe by that time of the day it may be better!!!.
Last night was actually an example of both. It wasn't the fog, per se, that messed them up--it was the low ceilings, and to a lesser extent, the winds. The ceilings prevented use of visual approaches, which means they couldn't land using both 28L and 28R, and could only use one of them. (The centerlines of 28L and 28R are too close together for being able to run ILS approaches to each runway.) Runways 01L and 01R are usually used for departures, but the surface winds at SFO put those two close to being out of crosswind limits, so it was land on 28R and depart on 28L. All that cuts their normal acceptance rate down from a normal 60 to 27-32, and it's then delay time.
If the ceilings are forecasted to arrive at a certain time, ATC will initiate a ground delay program to delay some SFO-bound flights at their departure points so as to match traffic demand to the reduced capacity. If they plan on reduced capacity starting 0400Z but Mother Nature throws the ceilings in at 0200Z, then demand will exceed the capacity (which has just been reduced) and some flights start to hold, and some may divert.
As far as your international flight is concerned, you have less to worry about in the sense that the flight time is so long that they don't get captured within any ground delay programs. You may a see a turn or two in holding, but should be able to get in OK, assuming of course that the visbility stays above landing minimums.
Atomsareenough From United States of America, joined Feb 2008, 543 posts, RR: 2 Reply 6, posted (4 years 6 days 3 hours ago) and read 3558 times:
Quoting Nibog (Reply 4): I fly in on the big EI green bird at 1pm(SFO time)
Unless it happens to be rainy that day, I think you'll most likely be fine in terms of weather delay. We get morning fog pretty regularly at SFO but it usually burns off by mid-morning.
Mikesairways From United States of America, joined Oct 2003, 635 posts, RR: 0 Reply 7, posted (4 years 6 days 3 hours ago) and read 3541 times:
Quoting CaliforniaMate (Reply 1): Looking out my window (I live 2 minutes from SFO) and its really foggy. Maybe that?
Goes to show how us folks in the slums of the south bay forget the dramatic climate change between SJC and SFO. Which reminds me, I'm going to the Giants game tonight and forgot my sweater...crap.
The red zone is for the immediate loading and unloading of passengers only, there is no stopping in the white zone...(Ai
Nibog From Ireland, joined Apr 2009, 310 posts, RR: 0 Reply 8, posted (4 years 6 days 1 hour ago) and read 3426 times:
Quoting OPNLguy (Reply 5): As far as your international flight is concerned, you have less to worry about in the sense that the flight time is so long that they don't get captured within any ground delay programs. You may a see a turn or two in holding, but should be able to get in OK, assuming of course that the visbility stays above landing minimums
Thank you for that detailed and behind the scenes evaluation OPNLguy,I really appreciate it,looking forward to visiting your neck of the woods!!!.
Quoting Atomsareenough (Reply 6): Unless it happens to be rainy that day, I think you'll most likely be fine in terms of weather delay. We get morning fog pretty regularly at SFO but it usually burns off by mid-morning
Thanks for that Atomsareenough ,I really appreciate it,looking forward to visiting your neck of the woods!!!.
Scutfarcus From United States of America, joined May 2000, 350 posts, RR: 1 Reply 10, posted (4 years 5 days 23 hours ago) and read 3283 times:
DAL763ER - Summer is sometimes the foggiest time of year in SF. We don't really call it "summer" until September and October - those are the nicest time of year.
The reason: In the spring and summer, the central valley of California gets really really hot, that hot air rises and the only major opening to replace that rising air is the Golden Gate - so it sucks very cold air off the Pacific right over San Francisco - resulting in wind, fog and low temperatures in the city.
OPNLguy From , joined Dec 1969, posts, RR: Reply 11, posted (4 years 5 days 23 hours ago) and read 3223 times:
Quoting Nibog (Reply 8): Thank you for that detailed and behind the scenes evaluation OPNLguy,I really appreciate it,looking forward to visiting your neck of the woods!!!
Any time...
Quoting DAL763ER (Reply 9): Can someone explain to me why SFO is in fog at this time of the year? It's the beginning of the summer...maybe it's a stupid question...
Just wanted to point out that, with respect to the situation on the night that the OP was referring to, the problem wasn't reduced visibility from fog, but the cloud ceilings that moved in earlier than expected and precluded the use of parallel visual approaches to 28L and 28R. Clouds can happen any time of the year, and absent the runways being further separated by a construction project or an earthquake, SFO will always be susceptible to big ATC delays..
DescendVia From , joined Dec 1969, posts, RR: Reply 12, posted (4 years 5 days 20 hours ago) and read 3102 times:
Quoting OPNLguy (Reply 5): The centerlines of 28L and 28R are too close together for being able to run ILS approaches to each runway.
Not to chime in off subject but that is why they designed, commishened, and built SOIA (Sim. Offset Intrument Approaches) for SFO. STL and CLE also "have" this type of approach. Just bring them in on the PRM approaches. ILS PRM is right down to 200 HAT and the LDA PRM is right down to 1440 DA (1127 HAT).
So unless the airline/airplane/crew is not certified/trained then the PRMs are OK. Actually if you look at the AAU page; if the PRM approaches are in use, crews/planes/airlines that are not certified need PPR (Prior Permission Required) to get a "slot."
OPNLguy From , joined Dec 1969, posts, RR: Reply 13, posted (4 years 5 days 19 hours ago) and read 3035 times:
Quoting DescendVia (Reply 12): Not to chime in off subject but that is why they designed, commishened, and built SOIA (Sim. Offset Intrument Approaches) for SFO. STL and CLE also "have" this type of approach. Just bring them in on the PRM approaches. ILS PRM is right down to 200 HAT and the LDA PRM is right down to 1440 DA (1127 HAT).
So unless the airline/airplane/crew is not certified/trained then the PRMs are OK. Actually if you look at the AAU page; if the PRM approaches are in use, crews/planes/airlines that are not certified need PPR (Prior Permission Required) to get a "slot."
So the options are there.........
While I'm well aware of those (and wanted to keep things simple with respect to different types if ILS approaches), my overall point remains the same, i.e. one isn't going to be able to run simultaneous ILS approaches to 28L and 28R and expect the airport acceptance rate (AAR) to be that same 60 that SFO has when they're severe clear and running VAPs to the 28s and departing the 01s. SOIA might get you a 32-36 rate (and maybe even a 45 rate if the planets line-up just right), and while those are better than a 25-30 rate, it sure as heck ain't 60, thus the delays still occur.
Wasn't that the old 1980s cop show that had the actor that more recently got himself all bulked up and starred in that other cop show called "The Shield?"
RFields5421 From United States of America, joined Jul 2007, 6140 posts, RR: 25 Reply 14, posted (4 years 5 days 19 hours ago) and read 2993 times:
Quoting Scutfarcus (Reply 10): DAL763ER - Summer is sometimes the foggiest time of year in SF. We don't really call it "summer" until September and October - those are the nicest time of year.
I've only spent much time in San Francisco in June and July. When the sun goes down, the weather is not nice.
I agree with the quote mistakenly attributed to Mark Twain
"The coldest winter I ever spent was a summer in San Francisco."
Dc10s2hnl From United States of America, joined Aug 2006, 154 posts, RR: 0 Reply 15, posted (4 years 5 days 18 hours ago) and read 2723 times:
Quoting Scutfarcus (Reply 10): The reason: In the spring and summer, the central valley of California gets really really hot, that hot air rises and the only major opening to replace that rising air is the Golden Gate - so it sucks very cold air off the Pacific right over San Francisco - resulting in wind, fog and low temperatures in the city.
And when it's coming early, they're calling it "May Grey" by our weather people down here in Socal. Last weekend there were a lot of arrival delays due to 28R being closed for some type of maintence/construction. From what I gather, it's going on most nights and weeks for a little while so I'm sure that's not helping much either.
Eghansen From , joined Dec 1969, posts, RR: Reply 17, posted (4 years 5 days 17 hours ago) and read 2590 times:
Quoting Scutfarcus (Reply 10): The reason: In the spring and summer, the central valley of California gets really really hot, that hot air rises and the only major opening to replace that rising air is the Golden Gate - so it sucks very cold air off the Pacific right over San Francisco - resulting in wind, fog and low temperatures in the city.
We have the same problem in San Diego along the coast. We refer to it as "May Gray" and "June Gloom." We have had very little sun on the coast for the last two weeks.
Quoting DescendVia (Reply 12): Not to chime in off subject but that is why they designed, commishened, and built SOIA (Sim. Offset Intrument Approaches) for SFO. STL and CLE also "have" this type of approach. Just bring them in on the PRM approaches. ILS PRM is right down to 200 HAT and the LDA PRM is right down to 1440 DA (1127 HAT).
From the AAUP:
"Simultaneous paralell approaches wil only be offered/conducted when the weather is at least 2100 feet (ceiling) and 4 miles (visibility)."
CWAFlyer From United States of America, joined Mar 2005, 621 posts, RR: 1 Reply 18, posted (4 years 5 days 17 hours ago) and read 2502 times:
Quoting DescendVia (Reply 12): So unless the airline/airplane/crew is not certified/trained then the PRMs are OK. Actually if you look at the AAU page; if the PRM approaches are in use, crews/planes/airlines that are not certified need PPR (Prior Permission Required) to get a "slot."
So the options are there.........
The mins for SOIA are pretty high (2100 and 4). Starting around 630pm or so, the ceilings were less than 1000 feet. Not good enough for SOIA.
ABQopsHP From United States of America, joined May 2006, 834 posts, RR: 3 Reply 19, posted (4 years 5 days 17 hours ago) and read 2292 times:
Yep, my first visit to SFO was in June. What a surprise it was to see the fog roll in just b4 sunset. Then on my next visit I was prepared. However my Western flight had to hold for about 30 mins for flow control, because SFO had gone down to 1 runway that night.
JD CRPXE
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