Dry weather and mild daytime temps this week; much colder next wek?

Filed in Uncategorized by on January 14, 2008 40 Comments

California has once again entered one of the extended mid-winter dry periods that characterize climate here during the predominantly “wet” season.  A strong ridge of high pressure offshore is deflecting all storm activity north into Alaska and Canada, only to swoop back equatorward on the far east side of the blocking pattern over the central and eastern U.S. Heavy snowfall and cold temperatures will be prevalent across the eastern 2/3 of the U.S. for the next 3-5 days. For CA: expect continued dry weather this week. Seasonable temperatures are expected in NorCal, while it will be somewhat warmer than average in the south. Highs and lows will be generally 50-60/30-40 in NorCal and 60-70/35-45 in SoCal. Valley fog is likely under this stable pattern, esp. with wet soils from recent precipitation.  Some strong offshore winds are possible at times this week, especially in SoCal, as a result of cold air damming on the east side of the Sierras (850 mb temps of 5 to 6 C over coastal CA and -4 to -5 C over W. Nev.). The powerful ridge currently over or just offshore CA will very slowly retrograde back towards the west over the next 7 days. The models always have extreme difficulty with this particular pattern for some reason, so explicit model forecasts are not really useful more than 3-5 days out at this point. Given the model tendencies and the current moderate-strong La Nina base state, I would expect that there is a decent chance of some very cold weather over the state of CA before the end of the month. It will almost certainly be bitterly cold over 80-90 percent of the Continental U.S.; the question is whether not not (or to what degree) this unmodified Arctic air may make it west of the Rockies. The GFS and ECMWF have been flip-flopping over the past few days, but each model has had its fair share of weird and unbelievable prognostications (heavy snowfall in San Francisco, deep freeze in San Diego (and I mean on the beaches!)). Needless to say, the circulation downstream of a shifting or developing Rex-blocking pattern is hard to model (at best), so we need to keep an eye on the potential for extremely cold weather in the not-so-distant future. A similar pattern developed last winter and did eventually result in very cold temperatures  and some low-elevation snowfall over the state. This is generally not a pattern conducive to major precipitation events anywhere in the state (dry and cold airmass) but it can certainly result in interesting or dramatic conditions. The only exception is if the pattern becomes very retrogressive and pinches off a strong cutoff low offshore of CA, as the GFS has indicated a couple of times in the past 24 hours. It’s also possible that we have 2-3 weeks of dry weather with chilly mornings but nothing really spectacular as the Arctic airmass misses us 500-1000 miles to the east. We’ll see. 

  • http://weatherwest.com/current_weather Daniel Swain

    And a bit of a milestone today for Weather West: 50,000 words of weather discussion over the past two years.

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    Hey, my post got deleted again!

    Anyway, the GFS has been a veritable soap opera this week with all kinds of dramatic and unlikely scenarios being presented, as well as more boring, mundane ones. It doesn’t have any consistency though, so like you said, after this week, who knows?

  • Dan the Weatherman

    Hopefully some of those patterns offered by the GFS do not pan out such as a deep freeze to the beaches of San Diego, as that will certainly kill off plants like the freeze of last year (about this same time in January) did in the Inland Empire.

  • Dan the Weatherman

    I also dont want to see this dry spell last the rest of this winter. We still need to receive more significant snow in the Sierra and rainfall down here to provide even more relief as we are not out of the drought yet.

  • jmello65

    what do u mean by much colder — instead of 70’s for highs — 50’s for highs —

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    I can’t get anything to post

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    wow we really need a good server. its like it can tell when i post about weather, and deletes those.

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    AHH!

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    AHH!!!!

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    I’ve posted those four posts and tried to post about 10 about rainfall but the rainfall ones were deleted.

  • Dan the Weatherman

    Inyo, that was happening to me a while back (a couple of weeks ago or so) when I had trouble posting. I could not post anything about the weather, but was able to post complaints about not being able to post.

  • Dan the Weatherman

    It seems that this inability to post is intermittent. I have not been having trouble posting as of late, but that of course could change any minute…

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    I don’t understand how it found the weather posts, though. Is there some elaborate spam filter that hates weather?

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    I just made another weather post, it was deleted! Let’s see if this one posts.

  • http://weatherwest.com/current_weather Daniel Swain

    Again, folks, I don’t know why these posts are being deleted. How about this: retain a copy-and-pasted version of a post you think is likely to be deleted. If the post never shows up, email me at ” owner AT weatherwest.com “, and I’ll see if I can post it myself using credentials. Maybe it’s a bizarre permisssions issue–if that’s the case, maybe I can resolve it. The server is actually quite good, I can assure you: there is a particular reason why certain posts are deleted and others aren’t. I looking at the filter to see if it’s trying to block “weather spam” ads or something ridiculous like that…

  • jmello65

    i posted one too and it disappeared

  • jmello65

    i would like to see more rain for jan-2008 — still another dry january — only 1.84 for 2008 — only 0.69 more than last year 2007 when only 1.15 fell — in jan 2006 we got 0.77 and 2005 5.82

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    The posts that got deleted were all variants of “Well, La Nina is decreasing, and we’ve had a fair bit of rain this year, so I feel like once the high moves on we will get some more good storms in Ventura”.

    Also, does anyone watch the GENS model? What is it? I’ve never really noticed it before.

  • Tom in San Diego

    Inyo I notice it does that when I spend a lot of time composing a post (Murphy’s law). Make a copy and wait a while. then try it again or break it up. I know its frustrating.

  • Tom in San Diego

    Jmello,

    See my answer to your question. on the last thread

  • jmello65

    lost another post

  • jmello65

    another disappointing mont rainwise only 1.84

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    GFS has rain again, or snow?

  • David

    or sould i say low snow levels or vary low snow levels

  • nicholas

    0Z run GFS was quite cool and wet but not as cool as the past runs. GFS 6Z run was a bit colder but with a lot less moisture and more east.

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    GFS still fully inconsistent. Looks like a windstorm tomorrow

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    The latest GFS just has random speckles of light rain all over the place, it doesn’t even make sense

  • nicholas

    Inyo I saw that as well. The only thing I could think of is a cold air pocket where the showers are very isolated.

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    yeah maybe that is how it represents ‘widely scattered showers’ when it doesn’t know exactly where they will occur. Apparently the european model is a little wetter… still no gullywasher.

  • Tom in San Diego

    OFGS, It’s January! Sunny and windy this week, dense morning fog and a little cloudy and cooler next week , possible frost warnings. Otherwise clear cold nights and warm sunny days. No rain insight. Thats all, end of handwringing drill.

  • http://weatherwest.com/current_weather Daniel Swain

    We may have a cutoff to deal with next week and the possibility of very cold air aloft. Haven’t had one of those in a while…

  • Dan the Weatherman

    The NWS 6-10 day and 8-14 day outlooks have been flip-flopping between near normal and above normal precip for Socal for the last couple of days. Whether that means we will get any rain remains to be seen, although the forecast discussions for San Diego have been hinting at least a possibility of rain by next Monday.

  • http://weatherwest.com/current_weather Daniel Swain

    And…just for comparison…

    Current conditions at PBAR (Barrow, AK–on the northern Arctic coast):
    Air temp.: -44 F
    Windchill: -72 F

    They are used to this kind of weather up there, of course.

    But still…

  • Dan the Weatherman

    Brrrrrr! Makes me cold just thinking about it.

  • Dan the Weatherman

    That would lead to frostbite of exposed skin the second one walks out the door and worse…

  • http://weatherwest.com/current_weather Daniel Swain

    Yep. Hard to imagine it being more than 50 or 60 degrees colder than when I was there.

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    Wow, the 50 degrees and 1 mph winds in Ventura seem cold enough for me

  • jmello65

    when is the next rain ????

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    Monday or Tuesday, if we’re lucky.

  • jmello65

    is it gonna be a cold rain — low snow levels — maybe down to 1,000ft