Updating multiple fields from a HQL subquery

I have two entities, CatalogItem and StockItem, and I want to update two fields in the first one with values from the second one.

Right now i am doing it this way:

UPDATE CatalogItem ci SET 
ci.availableQuantity = (SELECT availableQuantity FROM StockItem si WHERE /* some conditions */), 
ci.physicalQuantity = (SELECT physicalQuantity FROM StockItem si WHERE /* the same conditions */)
WHERE ci.supplier.id = :supplierId AND ci.lastFeedUpdate < :updateTimestamp

Is there a way to do the StockItem subquery just once, retrieving both fields and using them in an update?

I can do it in SQL, with a native query, but I was wondering if there was a HQL way to achieve the same behavior.