It Feels Like the East

So much for blogging regularly.

Monsoon

It definitely feels like the East here today, as monsoonal moisture, which crept in Friday, was firmly entrenched in the area yesterday and today. This spells higher humidity for a change. Of course, most of the area didn't see any thunderstorms unfortunately, but some parts of SoCal did, including the San Bernardino Mountains, and areas north of LA. I guess temperatures were the interesting weather feature Saturday. Ontario hit 95, Riverside hit 96...balmy. More interestingly, LAX hit 81° on Saturday, which is the warmest they've been since the mid-April heat wave!

The real, true heat was short lived though, as a Catalina Eddy spun up this morning and is holding temperatures down 3-5 degrees in most areas, so back to reality for a change.

June Gloom

Sure, it's August. But June Gloom type weather has been dominant out here most of the month. That pattern looks to return starting perhaps Monday, as the cut-off low responsible for keeping the marine layer locked in all of last week actually swings through. We may not see the marine layer get all the way inland like it had been last week, but clouds are likely in most of the immediate LA area before burning off mid morning. This pattern looks to stay with us through Tuesday and perhaps Wednesday.

Late August Recovery?

Starting on Wednesday however, a pretty big ridge of high pressure is forecasted to begin building over the intermountain West. This should at least allow for a warm stretch of weather on Thursday and Friday for most of Southern California, except at the immediate coast. Then, depending on what model you believe, either a weak cutoff will develop offshore, likely increasing the marine layer (though the Inland Empire and deserts will likely still cook), or a weak disturbance spinning off the upper low in the Gulf of Alaska is going to pinwheel into the Northwest and lead to a ramping up of the marine layer perhaps for next weekend.

What About Early September?

I know. We're getting a bit ahead of ourselves. But if you look at the climatology of Southern California, the warmest weather of the year is from roughly Aug 28-September 10th. The general rule of thumb is that typically, you can get your first real cool autumn air mass diving into the Great Basin around this time. That often translates to a Santa Ana event in SoCal, which leads to some of the year's hottest weather. The GFS model runs through September 8th today. There is nothing at all showing up on that model that would suggest an early season Santa Ana. Since 2000, there have been seven years which included a heat spike or Santa Ana event in that time period (late Aug/early Sept). So it would be trendy to forecast at least one period of substantial heating thru 9/10. Whether or not that happens remains to be seen. The last panel of today's GFS model shows a slightly deeper trough off the NW Coast. If that can swing inland to the Great Basin, that could be what's needed to generate this chain of events. But that's over 300 hours away...eons in meteorology. That said, having no solid Santa Ana signature right now is a good thing, given how dry the region is. We'll see.