Moisture Hole Reaches California

Today's water vapor imagery shows a dramatic "moisture hole" crossing central California.

Here are two amazing shots for 1 AM and  6 AM PDT this morning.
It almost looks scary.

These images show the temperatures of water vapor in the atmosphere.  White areas indicate lots of water vapor in the upper troposphere (roughly 15,000 to 30,000 ft), while dark areas indicate little.  Thus, dark colors show dry conditions in the middle to upper troposphere--the moisture hole.

This "moisture hole" is associated with a pronounced upper level low, as shown by the WRF model run last night (the 500 hPa, about 18,000 ft, heights are shown, with winds and temperature).  Moisture swings around the low, but values are less in its core.  Air that swings around the low rises more than air inside the low center.

This year we have gotten an unusual number of spring upper level lows heading into California...and there is another---even stronger--predicted for next week.

This pattern has brought clouds, precipitation and thunderstorms to northern CA, southern Oregon, and northern Nevada.  The NWS radars show lots of showers, some heavy moving westward over Oregon

And the lightning strikes for the 24-h period ending 1 AM this morning were impressive. Quite a number.

Precipitation totals over the West Coast for the 24-h period ending 8 AM had some significant totals over northern CA, which is obviously good for their water situation.  CA reservoirs are in very good shape and the late spring moisture helps keep the ground moist.

With all the action going south, Puget Sound was dry again, with only .08 inches in the Sea-Tac rain gauge so far this month.  Will we beat the all-time record (.12 inches)?   The next model run will probably provide the answer.