Potential "mini" freeze heading to California again

[Mauna Kea Cloudforest]

Looks like the feature the GFS has been advertising for a week now will come to pass, but it's looking slightly different and taking a straight shot south through inland Northern California and out towards Southern California. Looking at two Mornings with near freezing to some below freezing temps depending on how windy it will be, followed by a strong inversion with several cold Mornings in a row in low lying valleys afterwards. Looks like a lot of wind, so probably won't be cold while the front is moving through, but this might mean more upper 20's to low 30's for valley locations for another few days afterwards.

As per Hanford office;

MODEL DO RE-INTRODUCE A NORTHERLY FLOW WITH A FETCH
 EXTENDING TOWARD WEST CANADA. THEREFORE...THE COLD MAY RETURN
 TOWARD THE END OF NEXT WEEK AS DRY CONDITIONS ALSO RETURN.

[enigma99]

TWC has be near 70 almost everyday and mid 30s at night. I get to pass on this one

GFS shows most of the energy going west of the bay area no? That's a pretty cold shot though

Edited December 15, 2013 by enigma99

[Mauna Kea Cloudforest]

TWC has be near 70 almost everyday and mid 30s at night. I get to pass on this one

GFS shows most of the energy going west of the bay area no? That's a pretty cold shot though

This one heads straight to Socal.

[enigma99]

How is it looking Axel for Friday?

Also, we got one hell of an inversion layer in the Sac valley right now. At 11:10PM, it's 42F at my location at 160ft., but nearby foothill locations are actually in the low 60s! Tomorrow is looking hot up there.

in SoCal, many locations are still mid 70s at this hour. In the hills above Cupertino, I see upper 60s and one 70.

Edited December 17, 2013 by enigma99

[enigma99]

Thursday winds will be NNW 23MPH. That should leave everything dry as a bone and I expect temps in the valley to be at or below freezing

[Mauna Kea Cloudforest]

How is it looking Axel for Friday?

Also, we got one hell of an inversion layer in the Sac valley right now. At 11:10PM, it's 42F at my location at 160ft., but nearby foothill locations are actually in the low 60s! Tomorrow is looking hot up there.

in SoCal, many locations are still mid 70s at this hour. In the hills above Cupertino, I see upper 60s and one 70.

Here's how I think this will play out:

Low from Canada is absorbing a low currently 450 miles offshore, so dewpoints will go way up. It's blowing through fast, so winds turn onshore Wed and go Northwest Wed night, Northerly Thursday, and heads straight into Socal, with finally under building high pressure Friday onwards in Central and Northern California.

That would translate into chilly daytime temps Thur and Fri with chilly but not freezing overnight lows Thursday and Friday, possibly near freezing Fri AM. Things get tricky Sat and Sun due to the building inversion layer. I would expect the usual Winter Thule fog to setup since this storm is bringing in moister air. Things moderate pretty quickly next week but the Central Valley will remain under a persistent inversion layer.

So if I were to guess for the Central Valley: low 30's Thur AM, near freezing Fri/Sat AM mid 30's Sun AM with moderating temps after that.

[enigma99]

I don't like inversion layers let's chop the costal range haha. Actually there was a time when all Sacramento had was the Sierras and no costal range. Probably had better bay influence and no inversion.

[Mauna Kea Cloudforest]

Winds are a lot weaker than predicted, will most likely drop off tonite. Dewpoints are running high, though, so that should help things out. Here's what the forecasts are, I expect it to land towards the lower number due to the lighter winds than expected.

Santa Cruz: Accuweather=33F, Wunderground=39F

Modesto: Accuweather=32F, Wunderground=33F

Sacramento: Accuweather=31F, Wunderground=37F

The good news is that the high pressure builds in so quickly behind the departing front that even the Central Valley overnight lows will warm up quickly. The coldest forecast has everyone in the upper 30's or higher as of Saturday Morning.

So not even a mini-freeze, more like a mini-frost.

[enigma99]

50F right now @ 8:22, but it feels a lot colder.. got a nice warm cup of coffee

Edited December 20, 2013 by enigma99

[Mauna Kea Cloudforest]

Doesn't look like too many areas were affected this Morning. When I fired up Wundermap, I saw that the Central Valley was mostly in the upper 30's to low 40's thanks to Mono winds, i.e. downslope winds from the Sierra, and these kept the hills here in the SF Bay area and Santa Cruz county mild in the 39F to 42F range. However, wind sheltered valleys got nailed. Here are some of the Wunderground readings I saw for wind sheltered spots:

Boulder Creek: 25F

Scotts Valley below skypark: 25F

Scotts Valley Town: 31F north, 32F South

Los Gatos: 30F

Palo Alto: 32F

Menlo Park: 31F

Petaluma: 30F

I think that's about it for the month of December as the next two weeks are forecast to be quite mild. Enjoy the mini-Summer into the new year, stuff will have a chance to recover from the last freeze. Next thing to watch for will be an inside slider into the Great Basin around xmas, but should be even weaker than what just came through. Southern California is not gonna see a lot of heat out of this pattern due to the more Northerly flow during this period, so no Northeastern Santa Ana winds.

[enigma99]

Low of 31 for a few minutes. Not enough to hurt anything. Looking foward to the warmth

[monkeyranch]

36ºF low 1900ft. el. Meh.

32ºF for Camp Far West dam station at 259ft at the edge of the foothills. Inversion over last few days has kept foothills warmer than Valley. Have you seen Tule fog in Rocklin or Valley?

[enigma99]

No fog here.. Haven't seen any in over a year or so. It takes a pretty strong Tule fog to develop to get here

[enigma99]

Something bad developing around the Jan 8th timeframe. Hopefully the cold will be shut out somehow. -35c dropping into WA and perhaps on its way in to us. If we will get another freeze, it will be likely before Jan 15 as history shows

Edited December 29, 2013 by enigma99

[enigma99]

Nevermind.... GFS850 shows it going east. More warm weather for us

Weather 3 days ahead is unreliable and especially 10days+