Wednesday, April 26, 2017

mountain instability... (pm.26.apr.17)>

Wednesday's stats:

Low temp: 59.7F (15.4C)
High temp: 78.6F (25.9C)
Rainfall: none

It's partly cloudy just before sunset this evening, as we watch some very large cumulonimbus clouds over the mountains dissipate and fall apart.  Those thundershowers up-mountain this afternoon never made it anywhere close to us, but they were impressive-looking nonetheless.  Here, we enjoyed another day of good sunshine, in spite of that increase in clouds to our north and northeast -- with a high temp that was just a fraction of a degree warmer than yesterday's.

The remnants of a dying upper-level low pressure circulation continue to linger across the western Himalayas, with just enough colder air aloft to create some significant instability in the higher elevations during the PM hours.  Temps up there in the higher levels of the atmosphere will be warming a bit tomorrow (Thu) into Friday, but as that happens, lower-level temps will be warming as well... so that means we will probably continue to flirt with afternoon instability issues.  This is the kind of pattern where it is a rather complex and baffling equation to determine what kind of mountain thunder activity will get going -- or not.

This weekend there is another upper-level disturbance scheduled to sweep in from the northwest, but it should be weak and rather fast-moving.  Any risk of a passing thundershower or two should be mostly out of the picture again by Sunday evening, with some seasonably warm and relatively quiet weather expected as we push into the new month of May...