2020 - 2021 California and Southwest Weather Discussion Thread

[Reg]

9 hours ago, Omegaraptor said:

How rare is snow in Riverside? I feel like the occasional cold snap in Brownsville wouldn’t be worth having those awful summer temps, even if you get more thunderstorms.

Snow inside Riverside itself is extremely rare. It happened with some frequency in the 20th century up through the 1960s (maybe once every few years, or a couple of times a decade). Since the 1970s, however, temperatures have generally become too warm on average, even during the coldest of winter storms (or "inside slider" storms, which are more likely to give us snow or sleet with a lot of wind more than anything else). The last time I can recall snow having officially fallen in Riverside was January 12th, 2007, and even was basically a trace and was gone later in the day. Riverside is in one of the lower-elevation areas of the Inland Empire, along the Santa Ana River, where temperatures are much less likely to reach cold extremes. Many cities and towns just south and east of Riverside, where the elevation is slightly higher in those valleys (1500+ FT), snow still happens maybe once a decade, even in the form of just a few flurries for a minute or two. The flipside of that is, those valleys are much hotter than Riverside during the summer, and colder during the winter. Where I live in the Temecula Valley, about 30 minutes south of Riverside, it last snowed on December 31st 2014 (although I also observed trace amounts in February 2019) - elevation here in this valley ranges from 1000 FT to 1500 FT. The surrounding foothills and mountains are a different story, where snow happens at least every couple of years in the 2000-3500 FT range, and every single winter above 4000 FT.

[Reg]

July 2021 was very warm here inland - in Temecula, it was the third-warmest July and sixth-warmest month overall since 2000. There generally weren't any major heat waves, but here inland we simply endured sustained above-average warmth for nearly the entire month. The average low for July here was three degrees above average, while the average high was two degrees above average.

2021 through July 31st at my weather station in Murrieta:

[Anti Marine Layer]

Low clouds have only made it to San Diego County this morning. Welcome to August. 

[Pn1ct0g3n]

Yup, a very nice start to the month here. The week ahead should be near-normal across the board. 
 

Lots of activity over Nevada.

[Pn1ct0g3n]

Much of the Central Coast south of Monterey is enjoying some better clearing today compared to the endless gloom they endured in July.

[Thunder98]

Went down to 51F this morning with some patchy fog and on and stratus this morning. Felt a little fall like. 

[Reg]

98F here in Murrieta right now, another warm day, but less clouds.

9 minutes ago, Thunder98 said:

Went down to 51F this morning with some patchy fog and on and stratus this morning. Felt a little fall like. 

I read your post in Eric Cartman's voice.

[Pn1ct0g3n]

Upwelling event allows nighttime lows to dip lower. Got cool enough for heavy dew on my car though also noticeably less humid. 51? Wow that’s chilly for August, even up by you.

[Thunder98]

August is also the last month where the marine layer dominates the coastal areas.

[Pn1ct0g3n]

As is common, La Jolla is about the last place to clear on the whole southern coast today. Something about being just north of a headland makes clearing a lot harder.

[Thunder98]

The sun angle today is almost 6 degrees lower than it was on the Summer Solstice. Now I can tell the sun is a bit lower in the sky.  

[Anti Marine Layer]

Looks like inland areas could get pretty hot over the next few days. The days are now becoming noticeably shorter.

[Pn1ct0g3n]

Even SD got to a fairly toasty 81 today.    In Manhattan Beach, that would probably qualify as a statistical heatwave.

[Reg]

1 hour ago, Mr Marine Layer said:

Looks like inland areas could get pretty hot over the next few days. The days are now becoming noticeably shorter.

Its already been hot here since early July. I love the prospect of shorter days, though.

[Anti Marine Layer]

Looks like it was warmer at the coast today.

[Reg]

12 minutes ago, Mr Marine Layer said:

Looks like it was warmer at the coast today.

[Pn1ct0g3n]

Yeah, it was. Definitely a whole lot sunnier. Let’s see how the week plays out.

[Pn1ct0g3n]

Large scale water temps have been mostly stable. The recent cooling seems confined to right against the coast, though it’s significant.

[Thunder98]

5 minutes ago, Pn1ct0g3n said:

Large scale water temps have been mostly stable. The recent cooling seems confined to right against the coast, though it’s significant.

I can see some blue right on the  LA County shores...

[Jesse]

18 minutes ago, Thunder98 said:

I can see some blue right on the  LA County shores...

[Pn1ct0g3n]

Ended up nice and warm despite that. A great day for the beach.

[Thunder98]

A cool low of 50F this morning in Santa Maria with no marine layer at all!

 

Nice taste of early fall!

[Pn1ct0g3n]

Corner thermometer reads 77F — highest reading in a while for west of Sepulveda. 

[Reg]

107F here in Murrieta today.

[Pn1ct0g3n]

Plenty of 90s away from the coast. Some beach cities broke 80.

[Anti Marine Layer]

Hot day today as I returned to the office for the first time since March 11, 2020.

[Pn1ct0g3n]

Significant cooldown right up against the coast, though it remains relatively warm just offshore. It’s a good day to visit the beach, but go in the water and you might be in for a surprise. Unless you’re in Avalon.

Stratus field is more coherent today with nary an eddy in sight.

[Pn1ct0g3n]

Pretty typical start so far to the final month of meteorological summer. 

[Reg]

105F here in Murrieta today. Summer not holding back.

[Pn1ct0g3n]

A hair cooler than yesterday here at the immediate coast. The marine layer has mostly stayed out to sea though it’s starting to reform right now.

[Pn1ct0g3n]

Uneventful today, normal early August conditions. A dry westerly flow continues. Monsoon also seems fairly quiet over AZ.

[Thunder98]

Unusually cold today, only 66F right now.

[Pn1ct0g3n]

33 minutes ago, Thunder98 said:

Unusually cold today, only 66F right now.

Near to slightly below average down here, including inland. The coastal jet has stayed strong farther north, so you’re likely getting a lot of ocean air that hasn’t been modified much by the sun or land.

[Reg]

Another warm one today, 102F.

[Thunder98]

High today of 69F. Very stupid

[Pn1ct0g3n]

1 hour ago, Thunder98 said:

High today of 69F. Very stupid

Last year, we had a run of days in my city in mid July and again in August that barely reached 66 in full sun, and dipped into the 50s as soon as the sun went down. It was literally like April and I couldn’t remember anything like it in my life, even in 2010 it was warmer than that when the clouds broke.

[Anti Marine Layer]

Temperature disparity. A feature of microclimates.

[Pn1ct0g3n]

Seeing some eddy circulation this morning.

[Pn1ct0g3n]

Dixie Fire just took out the town of Greenville! Tons of smoke being pushed north into central Oregon.

[Thunder98]

Unusually windy today with sustained winds around 23 mph with gusts near 30 mph. Very Spring like....