Snow in Los Angeles

[aveosmth]

Hello everyone,

The recent hail storm that we had has inspired me to do some research on incidences of snowfall in Los Angeles, California. It has never snowed in my 30 years here in LA but there have been close calls (i.e. snow level falling to 1000 feet). I am wondering what conditions would have to be in place for this type of event to happen and what month would this be most likely.....I am also doing research on the last measurable incidence of snow (in 1957) and need help to find out what the conditions were then...any help to point me in the right place there would be vastly appreciated as well...thanks!!!

Sincerely,

Avery

[Stormsfury]

Off the top of my memory, I think it's only snowed twice measurably in the Los Angeles area ... but I can't find any information on this at the time ...

You might consider trying the Los Angeles/Oxnard NWS ...

http://www.nwsla.noaa.gov/

[Dave C]

A strong upper-level low moving through the area would be best chance. These systems have very cold air aloft and produce heavy convective showers, which if they come down heavy enough, can bring the rain-snow line down from higher levels. These conditions are produced when a deep upper level trough is situated on west coast and surface lows track across southern California bringing heavy rains and mountain snows to those areas. When an upper level low passes the area(after the surface low passes) it helps to bring the colder air to lower elevations and once in a great while snow will fall in Los Angeles, this has also happened in San-Fransisco on even more occasions. The event you mentioned in your post was most likely this kind of scenerio. Hope this clarifies it for you

[Stormsfury]

aveosmth ...

In 1957, can you give me a specific date on what day the snow event occurred? I can do some quick research (as to what Dave C) stated about the possible setup ... If I have the date, I can go back and reanalyzed the upper air pattern at that given time ...

SF

[weatherlover427]

I live not far from L.A. and I received snow in 1989 at my location (it accumulated to 2" because it a) was 22° out and b) I lived near the mountains, so CAA was a likely cause for that). I have also seen pictures of snow here in my current location (but I cannot remember what year they were taken). That hail storm (which is what I heard the Nov. 13th? storm was) is surely a rarity for this area though.

[aveosmth]

I appreciate everyone's prompt reply!! It looks like through further research, that the last measurable snow was January 11th 1949. It looks like only a trace fell in 57' and I am having problems locating that actual date. During the 10th-12th of January it snowed in Burbank for 3 days straight and Las Vegas got almost 10 inches of snow!!

I work in the San Fernando Valley near Los Angeles, and people tell me there was an instance of snow in Woodland Hills about 30 miles WNW of Los Angeles. Any further help would be greatly appreciated!!

Avery

[aveosmth]

Looks like there was a major snow event in February of 1989.....up to 5 inches of snow fell in the San Fernando Valley...and even some snow in Malibu....I will try to find more details on this storm's makeup.

[weatherlover427]

That may be the one that I recall ... or it could have been later in the year ... however I was only 6-7 years old at the time so I don't remember.

[NEwxgirl]

becase of the prevailing storm tracks, and oceanic influence, LA sees little in the way of snowfall. what you would need the get snowfall into the lower elevations would be a strong upper level low with 500mb heights of at least 540 decamaters (though lower heights at or below 534 DM would be much better). Convective instability or the existance of Symmetric instability would be a plus also. Dynamical cooling associated with those two factors would help to cool deep layer temperatues to their wetbulb (and if the wetbulb temperatures are below freezing throught the layers in question to within a few hundered meters of the surface) and snow or sleet would be the result.

forecasters though would want to observe soundings to assure that wetbulb temperatures would support sleet or snow, in the regions which 500mb heights appear to be below 540 DM. Just like seattle you would also want a northeast (offshore) wind supress the marine influence. this is normally acheived behind and or to the north of the surface low. Given Symmetric instability, the forecaster would want to see a moist adiabatic lapse rate. it is more common though to see convective instability in this region as the upper air cold pocket in contrast to the warmer air at the lower levels would increase temperature lapse rates and help with convective development.

850-700mb critical thicknesses must be below 1540 and 1000-850 thicknesses must be at least 1300. it is much easier to reach the critical values for 850-700 thickness in LA than what it is to reach the critical value at the lower levels. much of the reason why LA sees little snowfall

[weathafella]

Looks like there was a major snow event in February of 1989.....up to 5 inches of snow fell in the San Fernando Valley...and even some snow in Malibu....I will try to find more details on this storm's makeup.

I lived in LA from 1976-1991..thankfully in New England now. But I remember having to drive from LA to Santa Barbara early on that Monday morning in Feb 1989. It had rained the previous day and there were actually patches of ice near the median strip of the 101 FWY. The next morning I was running in Santa Barbara with temps in the 20s. That night, back in LA..lived near LAX, there were tons of reports coming in from the Valley reporting a bona fide snow event.

There were a few other times when it was close and once after clearing the mtns had snow all the way down to as low as you can see. But not within 10 miles of the ocean.

I believe thought, in 1925 or some year around then, several inches of snow were measured at UCLA. So its happened but its quite rare.

[LehighValleyForcaster]

It just happens.......................when conditions are right.

I am from California and have seen this happen.
_______________________________________________________


Year Month & Amount of Snowfall
1922 January (trace), March (trace)
1935 December (trace)
1947 December (trace)
1949 January (slightly more than 0.3 inches)
1950 April (0.2 inches)
1951 February (trace), March (trace)
1952 January (trace), March (trace), December (trace)
1954 January (0.3 inches), February (trace)
1957 January (trace)
1962 January (trace)


JAN. 3,1942....LOS ANGELES


JAN.13,1950...LOS ANGELES


JAN.28,1957....LOS ANGELES


JAN.28,1957....LOS ANGELES

[aveosmth]

I appreciate everyones prompt replies.....and those pictures are mind boggling!!!!!! Just a quick question....what would be the best resource to find the conditions for the February of 1989 snow event??? Also, it looks like the previous events were in the 50s & 60s...im wondering how difficult it would be to get data from back then....TIA


Avery

[aveosmth]

Hello everyone,

Not to suggest that we would get snow in Los Angeles from this storm expected to hit Chrismas Day, but I'm wondering if this is what we are looking for dynamics wise.....I'm thinking that we would have needed a much more arctic & stronger high pressure system ushering in that cold air from canada....and of course departing the area at the right time so that the low from the Pacific would have its full punch.......

Thoughts & comments??? BTW, I'm still looking for the conditions on that 1989 storm, I've searched the NOAA & cant find anything there, maybe Ill hit the local library after the holidays....

Aveosmth

[PTrackerLA]

Nice pictures!

[verycoolnin]

I remember seeing a news report in the mid/late 90s that said it was snowing in LA.

[aveosmth]

The city of Los Angeles spreads out into the San Fernando Valley and some adjacent foothills......so that is definitely possible that it snowed in that area of Los Angeles.....but the downtown area of L.A. hasnt seen the white stuff in 40 years or so.

[wxnut]

Here is a link to a page that has info on snow events for Los Angeles County, particularly LAX and the Civic Center. Snow in LA is a VERY rare event and anyone who gets to see it is very lucky!

http://www.losangelesalmanac.com/topics ... r/we17.htm

[aveosmth]

We're getting our coldest air of the season tonight and into tomorrow night, with a storm coming in on Sunday.....hopefully we will see the lowest snow levels of the season!!!!!!!!!!!