I thought the most interesting part of the NHC Discussion is when they said, "THE EXACT FATE OF FELIX OVER THE GULF OF
MEXICO REMAINS SOMEWHAT UNCERTAIN SINCE THERE IS SOME POSSIBILITY
THAT A TROUGH OVER THE CENTRAL U.S. COULD ERODE THE RIDGE MORE THAN
CURRENTLY ANTICIPATED...WE ADVISE AGAINST PUTTING TOO MUCH EMPHASIS
ON THE EXACT NHC FORECAST TRACK AT 4 AND 5 DAYS."

You see the low forecast to "spawn" this trough on water vapor imagery over the Gulf of Alaska.

EDIT:

From the WFO Lake Charles, LA AFD:

"TOWARDS FRI INTO NEXT WEEKEND...ANOTHER TROF WILL SWING SE ACROSS
THE ROCKIES...AND HELP LIFT THE UPPER LOW/TROF EASTWARD OUT OF TX.
STILL VERY UNCLEAR HOW THIS MAY PLAY IN THE FUTURE TRACK OF FELIX...IF
IT EVEN EMERGES INTO THE S GULF. STILL WAY TOO EARLY TO CALL."