Caught by surprise

They caught me by surprise:

 

It's been a good year for Painted Ladies (Vanessa cardui), but today numbers were noticeably higher.  

While photographing one for the record, I noticed another species nearby:

 

This Red Admiral (Vanessa atalanta) was also nectaring on Sea Thrift (Armeria maritima) along the Bodega Head bluffs.

Not long after this, I flushed a large dragonfly (a darner) from near the trail.  Interestingly, its wings were shiny, indicating an individual that had emerged from a wetland not too long ago.

And then I saw this butterfly land among the grasses momentarily:

 

Orange Sulphurs (Colias eurytheme) are common inland, but I only seen them occasionally on Bodega Head.  

I've mentioned before that Bodega Head is not the best place for butterflies and dragonflies — it's generally too cold with strong northwest winds coming off the ocean.  However, there are certain conditions that create potential for interesting insect viewing — e.g., when the winds are from the south or east and the thermometer rises.

The strange thing about today was that I hadn't really noticed these conditions, and there were lots of butterflies and at least a sign of dragonfly movement along the coast.

Had I just missed it?  I looked back at the weather data for the last few days.   The maximum air temperatures were about 57°F and 58.5°F.  Those temperatures are about average, and in fact it was warmer earlier in the month.

 
Then I looked at the wind.  I checked for the percentage of winds that came from the south, south-southwest, and south-southeast during the last few days.  Here's what those percentages looked like:

April 22 — ~15%

April 21 — ~14%

April 20 — ~35%

Below is a visual representation of the winds on April 20th:

 

Did the winds on Monday, April 20, encourage a strong northward push of butterflies and dragonflies?

I don't know, but it's worth keeping an eye out for these events and noting the weather around them.