ONE LAST WINTER GASP?

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Expect beautiful spring weather with occasionally gusty winds at times as storms mostly pass to the north of California over the next week or so.

By mid-week, a trough dropping south over the West will bring slight cooling and perhaps a few clouds. We’ll stay dry.

By the weekend, that trough will move east, with a weak ridge bringing warming temperatures into the 70s.

Spring is cutoff low season. As the jet stream pulls north, any rain we get usually comes from a low that gets “cut off” from the main circulation, and wanders down the coast.

That may be setting up for next week, at least if the GFS model can be trusted.

If a low digs this far south, we’ll have showers (at least) and cooler weather around Tuesday of next week, the 18th.

The other models are not yet on board. European model keeps the rain to our north, for now at least.

At this point we usually look to the ensemble models for guidance. They show a gradual trend toward wetter, more unsettled conditions beginning next week, with low pressure digging south for at least a few days, and a trend toward rain or showers.

At this time of year, mid April, we don’t normally see much rain. But the ensemble models now show us somewhat above normal for the 10 days from the 16th to the 26th of the month. The wettest model is the GFS.

Still, wet is relative in April. Since we don’t normally see much rain, this could just represent some showers.

But with this, temperatures may stay below normal for mid to late April.

We’ll be watching the development of this potential cool, showery “cutoff low” scenerio for the week of the 17th, and keep you up-to-date.

What’s actually nice about this scenerio is that it could slow the melting of the giant Sierra snowpack, which threatens to flood many areas of California this spring, especially the southern Central Valley. A slower, more gradual melt would be easier for water managers to control.

Speaking of that snowpack, in the central and southern Sierra, the snow water content is the highest in the past 70 years or so.

Another interesting graphic was recently put out by the Scripps Institution of Oceanography. They track and forecast Atmospheric Rivers along the West Coast. This shows where the main ones directly reached the coast during the past winter. As we already knew, lots of moderate to strong ARs brought us copious rainfall throughout the state.