Mar. 14th - Mar. 19th West (California) Late Winter Storm, Potential Heavy Rainfall & Low Snow Levels...a March Miracle? Options

[Beck]

Still too soon to know for sure.....but it is beginning to look like an incoming strong storm front, a rather cold one, may bring some much-needed rain to most of California, which has been seriously lacking in rainfall for the majority of the 2011-2012 winter.




Timing & intensity is still uncertain.....however, the bulk of the storm appears to mainly target Northern and Central California later this week. It's still unknown how this will affect Southern California, if it does at all. NWS forecasts are calling for rain chances to begin in SoCal late in the week, starting around Friday afternoon.

This currently has the potential to be the most significant storm of the season for SoCal, if it holds up.

This post has been edited by Beck: Mar 18 2012, 03:51 PM

[Beck]

Feel free to suggest other dates for the title.....as I'm still unsure of the exact time frame in which the storm will take place.

[FrostFuzz]

Snippet from the latest NWS forecast discussion

THE FAIR AND SEASONALLY MILD WEATHER WILL BE COMING TO AN END THIS
WEEKEND AS LOW PRESSURE TO THE NORTH AMPLIFIES SOUTH ACROSS CA. FRI
MAY BE WET AS WELL...BUT ANY PRECIP WILL BE LIGHT WELL IN ADVANCE OF
THE MAIN SYSTEM. STRONG ONSHORE FLOW SHOULD DEVELOP...WITH WIND
GUSTS OVER 60 MPH POSSIBLE ON WIND PRONE RIDGES AND DESERTS SLOPES
BY LATE FRI/SAT AS SFC PRESSURES DROP OVER THE INTERIOR.

THE 12Z GFS IS SLOWER DEVELOPING THE HEAVIER PRECIP INTO SOCAL SINCE
IT DOES NOT BRING THE COLD FRONT THIS FAR SOUTH UNTIL SUN MORNING.
THE 12Z ECMWF HAS SLOWED A BIT AS WELL AND NOW BRINGS THE FRONT AND
HEAVIER PRECIP THROUGH ABOUT 12 HOURS SOONER THAN THE 12Z GFS. THE
MODELS ARE GETTING CLOSER...AND GIVEN THE STRENGTH OF THIS SYSTEM...
WOULD EXPECT SOME SLOWING FROM EARLIER RUNS. CONFIDENCE IS HIGH THAT
WE WILL GET SIGNIFICANT PRECIPITATION AT SOME POINT OVER THE
WEEKEND...BUT TIMING REMAINS THE WILD CARD...AT LEAST THIS EARLY IN
THE GAME.

THIS SHOULD BE ONE OF THE MOST SIGNIFICANT WINTER STORMS OF THE
SEASON IF THE MODELS ARE CORRECT. THE ECMWF IS THE STRONGEST...WITH
500 MB HEIGHTS FALLING BELOW 540 DM OVER SOCAL AND 1000-500 MB
THICKNESS JUST BELOW 528 DM EARLY MON MORNING. GFS BOTTOMS AT 531 DM
MON AFTERNOON ACROSS SAN DIEGO COUNTY. EVEN THROUGH RAINFALL MAY BE
LOCALLY HEAVY...THE MAIN IMPACTS AT THIS TIME LOOK TO BE COLD...
SNOW...AND WIND. WITH THE THICKNESS LEVEL ADVERTISED...SOME SNOW
COULD FALL BELOW 2500 FEET FOR A TIME...AND A FEW RECORD LOW TEMPS
MAY OCCUR.

THE STORM SHOULD MOVE EAST OF THE AREA ON TUE OF NEXT WEEK...
FOLLOWED BY WARMER AND DRIER CONDITIONS.

The 12z GFS gives Riverside .82". I don't have access to exact ECMWF totals but I would guess it gives around 2". Looking forward to it.

[FrostFuzz]

Feel free to suggest other dates for the title.....as I'm still unsure of the exact time frame in which the storm will take place.

The date seems fine to me, although it looks like we may not see significant rain down here in the southland until Saturday or Sunday.

[Beck]

The date seems fine to me, although it looks like we may not see significant rain down here in the southland until Saturday or Sunday.

I put the 15th up there to include Northern and Central California, since they're getting the brunt of this storm anyway.

[Jet Developer]

Montgomery Field was an incredibly chilly 58 F this afternoon under FAIR skies and they are probably about 4-5 miles from the beach. Lake Forest was probably closer to 65 F. Now just imagine how cold Montgomery Field would be if the marine layer did not burn off today, and it's possible we could have near record cold SSTs.

[Beck]

Montgomery Field was an incredibly chilly 58 F this afternoon under FAIR skies and they are probably about 4-5 miles from the beach. Lake Forest was probably closer to 65 F. Now just imagine how cold Montgomery Field would be if the marine layer did not burn off today, and it's possible we could have near record cold SSTs.

Do you know where I could fine archives of coastal SSTs online? I want to compare this year's to past years.

[Jet Developer]

Do you know where I could fine archives of coastal SSTs online? I want to compare this year's to past years.

They have this site that shows the anomalies with data going back many years, but it's kind of hard to get accurate data since it's not focused to SoCal coast.

[Beck]

Downtown L.A. is 7.15" inches below normal today, but even worse is Bob Hope Airport (Burbank), which is now 9.97" inches below normal. Here in Temecula, we're 6.25" inches below normal.

Let's see how much of that deficit will be erased this weekend.

[Jet Developer]

Marine layer once again clearing out of San Diego County quickly this morning while taking much longer over northern O.C., L.A. County, and even the Inland Empire. It will probably blow back in over San Diego again this afternoon before O.C. and L.A as the sea breeze gets established there earlier.

[Jet Developer]

Downtown L.A. is 7.15" inches below normal today, but even worse is Bob Hope Airport (Burbank), which is now 9.97" inches below normal. Here in Temecula, we're 6.25" inches below normal.

Let's see how much of that deficit will be erased this weekend.

Seeing that it will be a very cold storm, I'm not hoping for any amazing rainfall totals as extreme cold and prolonged heavy rain just don't seem to go together here.

This post has been edited by Jet Developer: Mar 12 2012, 12:52 PM

[Beck]

Seeing that it will be a very cold storm, I'm not hoping for any amazing rainfall totals as extreme cold and prolonged heavy rain just don't seem to go together here.

True, but it does happen though. March-April 2006 is the best example I can think of.

[Beck]

NWS projecting snow levels to get down to around 3,000 ft Saturday Night/Sunday.

.FRIDAY...MOSTLY CLOUDY. HIGHS 59 TO 66.
.FRIDAY NIGHT...MOSTLY CLOUDY WITH A CHANCE OF RAIN. LOWS 42 TO
48.
.SATURDAY...RAIN LIKELY. HIGHS 54 TO 60.
.SATURDAY NIGHT...SHOWERS LIKELY. COLDER. LOWS 33 TO 43.
.SUNDAY...SHOWERS LIKELY. HIGHS 45 TO 55.

[FrostFuzz]

NWS projecting snow levels to get down to around 3,000 ft Saturday Night/Sunday.

Wow the ECMWF brings snow into the valley! It's only one run and it will probably be gone the next, but you can bet this one has my attention now. I will add screenshots in a bit. Also, there is a fair chance there will be a warmer storm immediately following this one, so that is something else to keep an eye out for.

This post has been edited by FrostFuzz: Mar 12 2012, 03:12 PM

[FrostFuzz]

Here are the ECMWF images, from wunderground this is only snow totals, not precip.
Frame 1

Frame 2

[Beck]

Wow the ECMWF brings snow into the valley! It's only one run and it will probably be gone the next, but you can bet this one has my attention now. I will add screenshots in a bit. Also, there is a fair chance there will be a warmer storm immediately following this one, so that is something else to keep an eye out for.

Here are the ECMWF images, from wunderground this is only snow totals, not precip.
Frame 1

Frame 2

Well that certainly is interesting. And I'm off Sunday, so if it by some miracle it does end up snowing, I'll be able to enjoy it

[aveosmth]

Well that certainly is interesting. And I'm off Sunday, so if it by some miracle it does end up snowing, I'll be able to enjoy it

What's even more exciting is that is sticking snow...so areas at even lower elevations will see flakes flying...LAX NWS mentioned lower elevation getting a mix of rain, hail and ice pellets...from the 12Z Euro, I'd put the snow flakes flying at 1100 feet or so...another good thing about the Euro is that it has a warm bias, so as long as the system stays as progged it could be interesting over the weekend!

[Beck]

What's even more exciting is that is sticking snow...so areas at even lower elevations will see flakes flying...LAX NWS mentioned lower elevation getting a mix of rain, hail and ice pellets...from the 12Z Euro, I'd put the snow flakes flying at 1100 feet or so...another good thing about the Euro is that it has a warm bias, so as long as the system stays as progged it could be interesting over the weekend!

We're at about 1300 feet here so we'll definitely be keeping a look out that night. I can't wait!

[alxz310]

The cold front should bring us a fair amount of rain here, but I'm not liking the high resolution images on either the GFS or ECMWF at this point - as has been the case this winter, it seems once the colder air with heavy showers/potential hail moves in, along with it comes a NWerly flow. There's a dry pocket over the LA coastal areas on both the GFS and ECMWF with 1"+ of rain inland. Hopefully that changes, since this system looks really interesting

[Beck]

This looks to be imitating one of the March 2006 storms, around the 11th of that month. Temecula got 1.02" from it, and was the coldest storm in the area in quite some time. Traces of snow fell down to about 1600 feet.

This post has been edited by Beck: Mar 12 2012, 10:24 PM