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Posted at 1:00 PM ET, 02/23/2011

Snow in San Francisco? Could happen late Friday

By Jason Samenow

Unusually cold storm impacting West Coast

Temperatures are on the upswing across the eastern third of the United States, but a very stormy and cold pattern is taking hold over the West Coast. A winter storm warning is in effect for Seattle, where three to six inches of snow is expected through Thursday (including potential snowfall rates of one inch per hour north of the city into this afternoon). The same storm will dive southward, impacting much of California, Thursday into Saturday (from north to south). In the San Francisco Bay Area, the potential for some very rare snowflakes is on the table.

The San Francisco National Weather Service Forecast office writes:

ON FRIDAY INTO SATURDAY A RECORD COLD AIRMASS IS FORECAST TO DROP OVER THE REGION WITH SHOWERS AND POSSIBLE VERY LOW ELEVATION SNOW SHOWERS BETWEEN 500 FEET AND SEA LEVEL.

Measurable snow is very rare in San Francisco, and has only occurred in the area 11 times since 1856 according to meteorologist Jan Null of Golden Gate Weather Services, who has compiled a record. The last measurable snow to occur in San Francisco occurred in 1976 when one inch fell.

As for the snow potential Friday into Saturday, Null wrote in an email to colleagues: "The toughest part of the equation is whether the precipitation will phase with the coldest air during the coldest time of day. Any of a number of subtle changes to the airmass and its trajectory over the ocean could make dramatic differences to the eventual outcome."

In the North Bay Hills of San Francisco, at elevations above 1,000 feet, snow is a better bet than at sea level and a winter storm watch has already been issued for Thursday night and Friday:

ACCUMULATING SNOWFALL OF SEVERAL INCHES WILL BE LIKELY FOR ALL ELEVATIONS ABOVE 1500 FEET WITH A GOOD POSSIBILITY OF AT LEAST 1 INCH OF SNOW DOWN TO 1000 FEET.

As you head south toward Los Angeles, unseasonably cold temperatures are expected by Saturday with highs in the 50s and lows in the upper 30s Saturday night. Snow will be possible in its nearby hills. The National Weather Service notes model forecast "thicknesses" - a measure of how cold it is - are unusually low:

IF THESE VALUES VERIFY IT WILL BE THE LOWEST [COLDEST] THICKNESSES RECORDED IN AT LEAST THE LAST 10 TEN YEARS.

Be ready to bundle up, Hollywood.

By Jason Samenow  | February 23, 2011; 1:00 PM ET
Categories:  Latest, U.S. Weather  
Save & Share:  Send E-mail   Facebook   Twitter   Digg   Yahoo Buzz   Del.icio.us   StumbleUpon   Technorati   Google Buzz   Previous: Global warming, extreme events and weird weather
Next: PM Update: Quiet before growing rain risk Thurs

Comments

FYI - a recent tweet from TWC's Jim Cantore indicated that snowfall rates in Seattle itself were approaching 1 inch per hour earlier today.

Posted by: afreedma | February 23, 2011 1:10 PM | Report abuse

I've been there in July and it felt like it could snow at any moment.

Posted by: ennepe68 | February 23, 2011 1:20 PM | Report abuse

This 'global warming' is becoming more difficult to deal with everyday.

Has anyone heard from Al Gore lately on how to handle the situation?

Posted by: dharper2 | February 23, 2011 1:35 PM | Report abuse

Ole La Nina and her boyfriend Global Warming.
When those two are together, mans intense knowledge of the weather, becomes nothing more than plausible assumption.

Posted by: BELLASNOWQUEEN | February 23, 2011 1:39 PM | Report abuse

I lived in Fremont when it snowed in 1976. It didn't stick in my part of the city, which was barely above sea level. Looking to the east at the hills and Mission Peak, however, I thought they were obscured by clouds. Nope, all snow. Usually, only the peak got covered every other winter or so but not that time.

Posted by: beetsnotbeats | February 23, 2011 1:46 PM | Report abuse

"Measurable snow is very rare in San Francisco, and has only occurred in the area 11 times since 1856..."

omg! that sounds horrible!

Posted by: walter-in-fallschurch | February 23, 2011 1:55 PM | Report abuse

Bay Area snow history:

SNOW DAYS
Snow is not rare in the local mountains, but the last time there was a significant covering of snow at sea level in the Bay Area was 35 years ago. Here are local snowfall events and amount of snow.
Feb. 5, 1976, 1"
Jan. 15, 1952, .3"
Dec. 11, 1932, .8"
March 3, 1896, 1"
Jan. 16, 1888, .1"
Feb. 5, 1887, 3.7"
Feb. 7, 1884, 1.5"
Dec. 31, 1882, 3.5"
Jan. 12, 1868, 2"
Dec. 25, 1862, 2.5"

I was there for 1976. The whole winter was very cold as I recall.

Posted by: dhb2 | February 23, 2011 2:02 PM | Report abuse

@dharper2 "This 'global warming' is becoming more difficult to deal with everyday."

Climate, weather... climate, weather. No difference, right? Same thing, right?

Posted by: ennepe68 | February 23, 2011 2:06 PM | Report abuse

ennepe68,
in addition to the weather/climate distinction, maybe part the problem some folks have with global warming is the GLOBAL part. e.g., it's cold in X so it must be cold everywhere.

Posted by: walter-in-fallschurch | February 23, 2011 3:06 PM | Report abuse

Walter in Falls Church is right...I'm from SF and the lack of snow is horrible...love DC but moving to Vermont when i retire.

Posted by: rivergirl1 | February 23, 2011 3:08 PM | Report abuse

Personally, I believe the lack of snow here this year is due in large part to all the hot air emanating from Capitol Hill.....

Posted by: TBAlexandria | February 23, 2011 3:55 PM | Report abuse

Global warming predicts wild swings in extreme weather. Hotter hots, colder colds, bigger storms, 100 year floods every 10 years.

Go ahead, make it about politics. Feel free to try debate what to do about it but remember: Above 350 ppm atmospheric CO2, the climate will change. Physics and Chemistry don't negotiate.

Posted by: thebobbob | February 23, 2011 3:58 PM | Report abuse

I am ready to drive two days to S.F. just to see the snow. The first snow for S.F. since 1976? Time to dust off the camera. I just wish gas hadn't hit an all time hit note this week with the protests overseas.

Thomas Chi
Author
PresidentSarah.Net

Posted by: ThomasChi | February 24, 2011 2:20 AM | Report abuse

Posted by: Mr_Q | February 24, 2011 11:59 AM | Report abuse

NOAA’s CSI explains record snows: global warming not involved

---begin quote---
Specifically, they wanted to know if human-induced global warming could have caused the snowstorms due to the fact that a warmer atmosphere holds more water vapor. The CSI Team’s analysis indicates that’s not likely. They found no evidence — no human “fingerprints” — to implicate our involvement in the snowstorms. If global warming was the culprit, the team would have expected to find a gradual increase in heavy snowstorms in the mid-Atlantic region as temperatures rose during the past century. But historical analysis revealed no such increase in snowfall.
---end quote---

There is an update at the bottom of the article detailing other NOAA employees who claim there is a human signature. Read the whole article and follow the links/references.

Mr. Q.

Posted by: Mr_Q | February 24, 2011 12:18 PM | Report abuse

"IPCC Forcast 'milder winters'"

they were right about the mild winters! it WAS a mild winter GLOBALLY. (but, was it cold where you live?)

when it's cold or warm or a blizzard or heatwave happens in the heavily-populated eastern corridor, or maybe in western europe, some sometimes think that's what's happening everywhere across the GLOBE.

december:
"The combined global land and ocean surface temperature for December 2010 tied with 1982 and 1994 as the 17th warmest December since records began in 1880, at 0.37°C (0.67°F) above the 20th century average. This was the coolest December on record since 2000. The Southern Hemisphere combined global land and ocean surface temperature was also the 17th warmest December on record, while the Northern Hemisphere combined global land and ocean temperature was the 20th warmest."

http://www.ncdc.noaa.gov/sotc/global/2010/12

january:
"The combined global land and ocean surface temperature anomaly for January 2011 was 0.38°C (0.68°F) above the 20th century average, resulting in the 17th warmest January since records began in 1880. Separately, both the Northern Hemisphere and Southern Hemisphere land and ocean temperatures were also 0.38°C (0.68°F) above the 20th century average, resulting in the 21st warmest January for the Northern Hemisphere and the 15th warmest on record for the Southern Hemisphere."

http://www.ncdc.noaa.gov/sotc/global/2011/1

now, granted it wasn't a record warm month, like so many months last year were, but still, 17th warmest is in the top 15%.

anyway, one winter does not a trend make. let's look back at the past 25 or so years:

EVERY december has been "above average".
http://www.ncdc.noaa.gov/sotc/service/global/glob/201012.gif

EVERY january has been "above average".
http://www.ncdc.noaa.gov/sotc/service/global/glob/201101.gif

they don't have data for february yet, but wanna bet it's above average? looking at that data, that ipcc "forcast" is not much of a prediction - it's more like "duh".

as for the snowfall prediction, i'm always skeptical when they make predictions like more snow here, less rain there or even higher temps there and so forth. those are what i'll call secondary or ever tertiary effects. it's like an effect of an effect (of an effect) - the first-order effect is GLOBAL warming... over the whole GLOBE.

Posted by: walter-in-fallschurch | February 24, 2011 12:56 PM | Report abuse

i realize that when i showed those graphics and stats relating to mild winters, GLOBALLY, i was guilty of the same thing smarty-pants deniers are when they chime in during a snowstorm with the "how's that global warming working for ya" crap because december/january is summer for half the globe....

so, anyway, here's a graph showing the northern hemisphere's (and southern hemisphere's) trend of EVERY dec/jan in the past 25 years having above average temps.
http://www.ncdc.noaa.gov/sotc/service/global/lo-hem/201001-201012.gif

and anyway, looking at those "dot maps" from the links in my previous post, you can see that most of the northern hemisphere was mild this winter.

Posted by: walter-in-fallschurch | February 24, 2011 1:11 PM | Report abuse

How's that decreased snowfall for North America prediction working out? ;)

Mr. Q.

Posted by: Mr_Q | February 24, 2011 2:54 PM | Report abuse

not well at all. don't know about nationally, continentally or hemispherically, but dulles and national airports are reporting below average snowfall this season. i'm seriously hoping there's something to the opposite notion that AGW might cause more snow in my front yard. ;-)

do you live around here? for some reason i have the notion that you live in the pacific northwest.

Posted by: walter-in-fallschurch | February 24, 2011 4:55 PM | Report abuse

We prefer to call it the Great Pacific Northwest; Thank you very much. :)

Mr. Q.

Posted by: Mr_Q | February 24, 2011 6:46 PM | Report abuse

Yes, I live in the Great Pacific Northwest, where the weather and shifts in rainfall have been found to be natural. Who knew we had climate way before the SUV!

I for one, look forward to a little drier year(s). It is awful wet out here. Our teams are the Ducks and the Beavers. Go Beavers!

Mr. Q.

Posted by: Mr_Q | February 24, 2011 11:13 PM | Report abuse

The comments to this entry are closed.

 
 
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