Here in California, September can be an interesting month. It is “on the cusp” between summer and fall. Sometimes it is a hot summer month. Sometimes it is a cold fall month. Often it is dry.
So what’s happening now?
I’m sitting in my “easy chair” on the patio, under a ‘sleeping bag’ that has been opened to make a blanket of sorts. It’s cold.
At 8 AM it can often be a bit cool in the San Francisco Bay Area. Hot air inland can pull a blanket of fog in off the Pacific Ocean. Today is NOT like that. First off, I’m ‘south of the fog belt’ behind some mountains that keep the fog from getting here. Second, inland is cold right now too.
In Sacramento (State capital, about 80 miles inland from San Francisco and about 1/2 way to the Sierra Nevada Mountains) it is presently 56 F per Wunderground. Their predictions are:
Today Partly Cloudy 91 °F Partly Cloudy Tonight Clear 55 °F Clear Tomorrow Clear 99 | 64 °F Clear Monday Clear 100 | 57 °F Clear Tuesday Clear 100 | 59 °F Clear Wednesday Clear 99 | 57 °F Clear
Later in the day when it warms up in the sunny central valley, the fog might be pulled in. Not now. Presently SFO is also 56 F and Overcast; and all three of SFO, San Jose, and Sacramento report 0.0 winds. (But fog is predicted for this afternoon)
Today Fog 70 °F Fog Tonight Mostly Cloudy 50 °F Mostly Cloudy Tomorrow Partly Cloudy 75 | 54 °F Partly Cloudy Monday Clear 73 | 54 °F Clear Tuesday Fog 81 | 54 °F Fog Wednesday Fog 77 | 54 °F Fog
It’s not the fog part that’s interesting, it’s that “Mostly Cloudy” and “Partly Cloudy”.
In San Jose we have
Today Partly Cloudy 79 °F Partly Cloudy Tonight Clear 57 °F Clear Tomorrow Clear 91 | 54 °F Clear Monday Clear 93 | 54 °F Clear Tuesday Clear 88 | 52 °F Clear Wednesday Clear 88 | 50 °F Clear
What can we read into these tea leaves?
There are several interesting things that come out of this chart. First off, realize that the weather here comes from about 30 miles to 60 miles North East (up toward Bodega Bay). It comes in off the Pacific Ocean on a slant. (Sometimes on rare occasions from the South East). So for several thousand miles, the air mass is conditioned by ocean and sun and not much else. That current off the California Coast is cold, and the current NEVER gets warm in N. California. I’ve turned quite red swimming in it south of here in Santa Cruz and gone to near hypothermic, in August, when it was quite hot on shore in the sun…
Santa Cruz is a harbor, so the water warms a bit with the day / night sun cycles, still it’s pretty cold:
We can again see the modulation with sunshine, but the rapid plunge back to base cold levels at night and with no enduring heat retention from ‘back radiation’. There is also an interesting chart here:
San Francisco Area Average ocean water temperature in °F Place June July July Aug Aug Sep 16-30 1-15 16-31 1-15 16-31 1-15 Alameda 65 66 66 66 66 66 Bodega Bay 51 51 53 53 54 54 San Francisco, 58 58 58 59 60 60 Fort Point Santa Cruz 57 58 59 59 60 60
You can see that Alameda (inside San Francisco Bay, over on the East Bay side) is warmer while Bodega Bay (outside and more exposed to the current – it isn’t a very big bay) is colder and more representative of the offshore conditions. Santa Cruz is a tad warmer as it is a larger bay, but still fairly exposed to the ocean currents.
So for Sept 1, the offshore ocean is about 54 F, and it only warms a few degrees as you go inland a few miles. Also notice how remarkably stable those temperatures are. Bodega warms 3 F over the entire summer. Santa Cruz about the same. (but the Alameda station just sits there at about 66 F, already being solar warmed).
So those nightime temps are fairly consistent and a few degrees warmer than the ocean, but not a whole lot. The air does warm crossing the low mountains between there and here, but it's a fairly consistent small amount at night. Our lows are clearly tied directly to the ocean temperature and not much else. The ocean doesn’t change much at all, mostly showing signs of minor warming right near shore in the shallows and inland.
Notice that after several days of predicted "clear" in San Jose, the final night temperature is 50 F, whereas today with "partly cloudy" it is predicted 57 F. When the air is clear, more daytime warming happens and the onshore winds pick up cooling the evenings. Both cooling via ocean winds and cooling via night time radiation to space.
When it is cloudy, the air 'sits' longer and has time to warm from the ground ( that is a fairly constant temperature a few feet down. Nationally I think the average is 56 F and while I'd expect California to be a bit warmer, it won't be much.) So lower daytime highs, but higher nighttime lows.
Tomorrow, Tomorrow, there’s always Tomorrow
You can also see that tomorrow is predicted to spike up to 91 F Max then 93 F the next day, then slowly ramp down to 88 F. Fairly typical pattern. Stagnate the winds under cloud, cloud clears and solar heating begins, air starts to move under clear sky and both Min and Max get depressed from onshore cold air movement. Fog gets pulled in over San Francisco. Eventually cooler air or a bit more clouds reach Sacramento and the Great Valley inland, dampening the rising air there; and the winds slow. Repeat…
Send In The Clouds, There Must be Clouds
What is the effect of clouds? Well, first off, it modulates this whole air mass motion. That's kind of a big deal when you can have 10 F swings of temperature from it. Look at San Jose under partly cloudy and under clear. 79F and 93F. 14 F difference. Clouds matter, and they matter a lot.
The San Francisco prediction for Tuesday is kind of interesting, too. It has fog, but an 81 F high. WUWT? Well, sometimes the fog doesn’t come in until AFTER the day has warmed… So looks to me like San Francisco gets a couple of days of warming, up to 81 F, and THEN the air gets moving and the fog rolls in to cool things off late Tuesday afternoon / evening.
Now compare Sacramento temperatures to San Francisco. The major difference is just distance to water. There is a large ‘bay delta’ system of water with a shipping channel to Sacramento, so lots of water between the coast and Sacramento, but also a lot of dry brown farm land (California goes brown in the summer from no rain, except where there is irrigation. Irrigated places can be much cooler than the open range land. North East of Sacramento tends to be some of that range land, but along the bay / delta system tends to be green and irrigated, or the water itself).
For Sacramento, we have highs of about 100 F, while San Francisco is about 75 F. We get 20 F to 25 F of heating of the air as it moves from San Francisco, inland, to Sacramento. And that IS what it does. Right up the bay delta flat area. Sacramento is about 30 foot elevation, so not much ‘uphill’, and only 32 feet elevation 70 miles north of Sacramento. The whole central valley is very flat. So cool air flows in through the Golden Gate, over the bay delta toward Stockton / Sacramento, then spreads out into the Great Valley. Along the way is picks up about 20 F to 25 F of solar heating.
(In winter it can be exactly backwards. Dense “tule fog” sitting over the Central Valley holding temperatures down in the cold ranges while San Francisco can have a clear sunny day and be 20 F warmer in the sun… Similarly, the Sierra Nevada can be sunny, clear, and warm while the Central Valley sits under a cover of cold dank fog. It really does all come down to clouds and sun – including fog in the clouds portion.)
Looking At Metrics
Now we’ve got two metrics. It takes a few hours and about 80 miles of solar heated dirt to raise cold damp foggy air by 20 F to 25 F. As soon as the sun goes down, that heating is lost, and the air rapidly looses that heat, dropping back to within 4 F to 8 F of the lows at the origin point out to sea. Heat trapping? What heat trapping? Back radiation? WHAT back radiation? All I see is solar heating and ground / water moderation.
Next Wednesday, San Jose is back to a 50 F night time low, despite a 93 F daytime high a couple of days before. We cool from 57 F to 50 F under clear sky at night. Sacramento warms from 55 F to 64 F at night as the clouds clear off, but rapidly cools back to 57 F with a bit of air movement. Back radiation no help there. San Francisco sulking at 50 F to 54 F no matter what happens. Clouds being a bit warming, but San Francisco mostly just anchored to the ocean and fog. No back radiation help there.
The big take away from this profiles, for me, is that the WATER matters. As clouds. As fog. But that the CO2 doesn’t. Clouds coming and going modulate day time Max down and night time Min up, with the daytime drop more than the night time rise. Clear sky rapidly returns to ‘base settings from the ocean’ and ‘peak from the sun’.
One other bit of interest is to look at the almanac for today.
September 1, 2012 Max Temp Min Temp Normal (KSJC) 83 °F 58 °F Record (KSJC) 101 °F (1950) 44 °F (1895) Yesterday 69 °F 56 °F
What has “Global Warming” done for us? Well, not a whole lot. Our “Normal” is 83 F and yesterday was 69 F. We’ve cooled off by 14 F. Now I’m sure that Hansen and friends will assert that if we just average and homogenize that number enough we can find it’s really warmed. Bull pucky. We’re below normal. That isn’t warming. Playing statistical games with averages of intensive variables is just a Magic Trick to confuse the innocent and uncritical. Note that even our MIN has gone down by 2 F, so those ocean cold temps are not a lot different either, and may be a touch on the cool side.
The records are also interesting. Max of 101 F(!) – hey, I told you it can be a hot summer day here in September. Set in 1950. So 60 years of “Global Warming” have gotten us all the way to 32 F BELOW the record and 14 F BELOW the ‘Normal’.
The Min was set in 1895 at 44 F. Man that must have been one odd cold day. Perhaps I’ll look up the weather history and see what was going on. There are times that we have winter days warmer than that. OK, the ‘Normal’ is 14 F above the record low, and we’re presently 12 F above the record low. A bit cool, but not too far off normal. I must note in passing, though, that the MIN was set just about the time Hansen chooses to “start time” in 1880… I’m sure it’s just a coincidence /sarcoff;>
So, all in all, we’re more or less in the middle of the Min / Max record ranges and not too far off the ‘Normal’, but a bit cold.
Looks to me like “Global Warming” has done exactly and essentially nothing. It also looks like the local temperatures are strongly driven by the offshore water temperature (that has not risen) and clouds (that are a bit more this year) with CO2 having no visible effect at all; certainly not able to hold in any excess heating via ‘back radiation’ over the night. If it can’t do it for even 8 hours, how can it have any effect over decades?
It also looks like making an average of Min / Max and ignoring clouds just gives you a giant confounder from clouds as to what that average means. Ignoring the cloud percentage while making a Min / Max average is just rampant stupidity. Yet “that’s what they do”…
So, IMHO, it all comes down to clouds, sun, and winds. All things the climate model folks admit they handle badly and / or don’t handle at all. But they assert that if they average together what they do have it means something. Yeah, like that’s gonna happen…