Heat bursts

[JP Santiago]

I came across an advisory from the NWS office in Fort Worth tonight that was warning about the possibility of heat bursts with the collapsing thunderstorm cores in central Texas this evening.

This excerpt got me wondering, though:

THUNDERSTORMS CONTINUE TO SLOWLY DISSIPATE ACROSS CENTRAL TEXAS. THE
OUTFLOW FROM THESE STORMS WILL CONTINUE TO PRODUCE GUSTS IN EXCESS OF
50 MPH ACROSS PORTIONS OF CENTRAL TEXAS. IN THE WAKE OF THE STORMS...
SHOWERS WILL AFFECT BELL...FALLS...MILAM...AND ROBERTSON COUNTIES...
WHERE VIRGA MAY RESULT IN HEAT BURSTS WITH GUSTY WINDS. THESE WINDS
MAY KNOCK DOWN TREES...CAUSE DAMAGE TO SOME STRUCTURES...AND RESULT
IN POWER OUTAGES.[/b]

Virga can cause heat bursts? I had always thought that heat bursts were only due to collapsing storm cores.