SoCal - Rain or No Rain Next Week?

[osideterry]

I just looked up my main two sources for an extended forecast, and they are quite different. Any weathermen, professional or armchair, care to comment?

Edited April 1, 2009 by osideterry

[epicure3]

I think it will rain.

I have just assured that we will have roaring Santa Anas and temps over 90F.

[MattyB]

I'll wash the car to help with the rain coming.

[KMartin]

My UJEAS program shows lots of promise in Southern California. Here you guys go...

The official press kit to the UJEAS APR 2009 program is here, with images of the pattern itself.

http://www.scwxa.org/UJEAS/2009/4/ujeasapr09presskit1.html

Of course the forecast page I provide keeps you up to date on your wx in socal... bookmark it.

http://www.scwxa.org

The IN THE CARDS page has been talking about rain chances for a few days now and that page is here.

http://www.scwxa.org/cards.html

Many different pages provided to help you know the weather ahead in this region ...

Here is the discussion, hope this helps ...

April 2009 will be an interesting month, and different than March with some NNW flow storms by early-mid month, and some Southwest tropical moisture type storms after the 21st. No offshore Santa Ana Winds look likely this month unlike March ...

UJEAS in March went well with storm systems passing by to the North. Am going to put April in one of those months where we get good end season storms into the region for the Western USA, including the Southwest. I am seeing a pattern to bring these storms in after the 21st mainly but will shoot straight right now on what I personally see with UJEAS.

By April 7, 2009 the UJEAS shows a trough missing us to the North. This trough is also advertised on the EC and GFS models, however the EC wants a large storm, and the GFS wants a weaker system. The UJEAS and storm track put this storm as a weak system that will impact area further North than Southern California, however still providing the direction for a precipitation window. The storm track will be across the Rocky Mountain and Northeast around a ridge centered across the nation's mid section, only to dive back down on the Eastern USA. A ridge looks most likely between two troughs by this time.

After the 7th, the flow turns more North-Northwest which would allow storms to come into the Southwestern USA. Storms do look possible around this time, however not the moist Southwest flow that would bring good, and needed, precipitation amounts to the region but anything is welcome to show.

Around the 14th this North-Northwest flow breaks down to a more zonal flow. This pattern means that dynamics for storms into the Southwest look slim and a dry period would arise once again.

After the 14th the flow kicks a large upper low into the Western USA, but may flirt with the Southwest, keeping it dry with a zonal flow across the Eastern USA.

After the 21st, things start to shift in the atmosphere. UJEAS is showing that we are going to enter a wetter pattern possibility as a Southwest flow sets up, which might I add is quite different than this past March. We should be opening the storm window back up once again.

Between then and the 28th we continue the storm window and if everything in the pattern continues, a large swath of moisture will be possible for much better rain development across the Southwestern USA with the storm track through the South-Central part of the nation on up into the Eastern Coast as a mega low looms over Canada.

Overall Thoughts: Will not go into how much rain could fall into the areas but the pattern on UJEAS does indicate that the Southwestern USA will have a number of systems into the area this month, with one or two being beneficial to the drought across the area. This looks most likely after the 21st with toward the 26th to 29th being the window for the best moisture inflow so we will wait that out and see how UJEAS does on it's first April run in the history of the project, which may end when the season is over, however I must stress that the pattern for around the 9th is favorable for a NNW flow storm that would trend over-water some, giving needed rainfall which will add to the monthly amount.

[happ]

Looks encouraging, Kevin esp since March was such a dud only 0.56 for the entire month at my station [14.28" for rain year jul-jun]. Cool into the weekend w/ remote chances of rainfall.

[KMartin]

I actually love April. For some reason it has the lack of ridging overhead and the change to spring so we could get these nice tropical like storms. The high sun angle provides better "convection" as well and just a very nice month. I know that this area sees better aprils than dry ones.

Early next week's storm looks good.

[happ]

Yes, the warming of the ground w/ disturbed weather overhead call result in some very violent weather. Remember the tornadoes in May last year out around Ontario?

[KMartin]

Yup, violent storms in APR_MAY can happen with the clash of the air masses here in SoCal. Here's the latest on the storm system and it looks like it could be a good size one for some ...

HAZARDOUS WEATHER OUTLOOK

SOUTHERN CALIFORNIA WEATHER AUTHORITY

APRIL 3, 2009 3:00pm Pacific Time

SOUTHERN CALIFORNIA ...

THE SOUTHERN CALIFORNIA WEATHER AUTHORITY HAS UPDATED A HAZARDOUS WEATHER OUTLOOK ...

A STORM STATEMENT IS PENDING ...

LATEST OUTPUTS SUGGEST THAT THE STORM ON UJEAS WILL COME INTO PLAY NEXT WEEK. AM GOING TO KEEP IT ON THE DOWN LOW IN TERMS OF DETAILS AND FINE TUNE IT AS IT COMES IN BUT WE DO SEEM TO HAVE THE NEXT WINTER STORM ON THE LIST, RODASH, AND A POSSIBLE CATEGORY THREE OR EVEN CATEGORY FOUR SYSTEM.

THIS STORM SYSTEM LOOKS TO HIT THE VANDENBERG AND SAN LUIS OBISPO AREAS LATER MONDAY EVENING OR NIGHT, FINALLY HITTING VENTURA, LOS ANGELES, SOUTH AND EASTWARD TUESDAY THE 7TH, WHICH WAS UJEAS' DATE OF TRACK. AM GOING TO GO WITH THE UJEAS RIGHT NOW AND GIVE THE TRACK THROUGH SOUTHERN/CENTRAL CALIFORNIA, HOWEVER THE UJEAS SHOWS THAT THERE WILL BE SOUTHWESTERLY FLOW AHEAD OF IT SOUTH OF THE TRACK SO WE MOST LIKELY WILL SEE MORE THAN JUST SPRINKLES OR DRIZZLE WITH IT WHEN IT HITS.

SNOW LEVELS LOOK TO BE AROUND 5,500 TO MAYBE 6,000 FEET WITH THIS SYSTEM AND THIS WILL BE A RESORT RELIEF IF IT STAYS IT'S CURRENT TRACK. LOOKING AT SOME GOOD SNOWFALL IF EVERYTHING WORKS OUT SO KEEP YOUR FINGERS CROSSED BECAUSE WITH ADDED CONVECTION OR THUNDERSTORMS OVER THOSE MOUNTAINS, SIGNIFICANT LOCAL SNOW AMOUNTS WILL BE POSSIBLE.

IN ADDITION TO THE SNOW, THUNDERSTORMS WILL BE LIKELY WITH THE SYSTEM AS WELL AS FUNNEL CLOUDS, SMALL TORNADO CHANCES, AND EVEN WATERSPOUTS SO MARINE WEATHER WARNINGS WILL BE NEEDED SO PUTTING THAT STAMP ON NOW.

THE STORM SYSTEM WILL HAVE GUSTY SOUTHWEST WINDS IN A STRONG MID LEVEL JET AND A STRONG 10MB ONSHORE GRADIENT SO GUSTY MOUNTAIN AND DESERT WINDS WILL BE POSSIBLE WITH IT. THE COMBO OF WIND+PRECIP WILL MAKE FOR BLOWING SNOW CONDITIONS IN THE MOUNTAINS.

THE STORM SYSTEM WILL DEPART OVER THE DAY WEDNESDAY FOR CALMER CONDITIONS ...

THIS MAY BE A DANGEROUS STORM SYSTEM ...

SCWXA - SCWXA.org

A Hazardous Weather Outlook is issued when an outlook for possible pattern changes and will or will not come to be. It is a general outlook to let the public know something is on the "horizon", similar to our "in the cards" page.

[happ]

Rain prospects are looking better in every model run. Kevin, can you venture a guess at POP levels? It would be very nice to pick up some rain in April even if it is accompanied by very cold temps. NWS mentioned possible record cold in upper desert\ Paso Robles for the month this weekend. Freezing temps in April makes palm aficionados uneasy

[KMartin]

I can't calculate POP. I actually don't like % lol, respectfully of course.

I like the flow, and the dynamics. The flow is consistent so if I had a POP choice, we are looking at 100%

[happ]

I was actually surprised to record 0.12 from a 5-6 minute moderately heavy shower that passed over last night. Anyone else get rainfall? Next system\ Friday looks a bit more favorable.

[osideterry]

I didn't get enough precip to darken the patio completely. Skies were totally clear at sunrise.

[BS Man about Palms]

I got just enough to wake me up, and then as i listened for a moment or so more, it stopped too.

[KMartin]

Someone hates Southern California. All these storms were perfect, but something is always wrong with them, either by shape or track. Even Friday's storm looks like blah in most areas, with just showery nature events, maybe an iso tstorm or small hail ...

Edited April 9, 2009 by KMartin

[Scott]

Got enough to qualify as a watering but was hoping for more.

[MattyB]

I got .10" tuesday evening overnight. I'm hoping for more tomorrow.

[PalmGuyWC]

Same-O for me......just an off and on drizzle out of the latest storm. Dark clouds but not much coming out of them.

Dick