"So is it just me or is there a completely separate broad low-level circulation along 25N 90W?"
Is the circulation you mentioned the same one being mentioned in this forecast discussion?
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 347 PM CDT TUE JUL 6 2010
.DISCUSSION... MAIN REGIONAL ITEMS OF NOTE INCLUDE THE UPPER LOW EAST OF THE LOWER TX COAST...THE SURFACE LOW ON THE SABINE JUST SOUTH OF KSHV...AN UPPER RIDGE OVER N TX AND THE BIG BEND...AND THE TROPICAL WAVE OVER THE SE GULF AND W CARIBBEAN.