I disagree with that to an extent. In fact, you could argue pattern becomes even more critical. Late June and July..we bang bang out 90 "relatively easy"...you don't need that crazy anomalous pattern or airmass...earlier than that and later than that it likely need it more.
The look on the pattern (at least through the end of the month offers a much higher potential for heat against average or below-average. With the strength of the western and WAR ridge's there is plenty of room and window to pinch heat into our region. We have to solely rely on troughs to dig in and for some actual cold fronts to move through. Maybe perhaps some weaknesses develop within the WAR but as long as it stays that developed it's going to take numerous trough ejections and fronts to really weaken in.