NCEP Ensemble Mean 500 mb Height Anomalies (6/3/2008 0z 120 hours):

Composite 500 mb Height Anomalies for Past Similar Patterns:

Select Highest Temperatures during Past Periods for the Composite 500 mb Height Anomalies:
June 4-11, 1953:
Boston: 94°
Burlington: 85°
Montreal: 77° (25.0°C)
New York City: 93°
Ottawa: 76° (24.4°C)
Philadelphia: 94°
Richmond: 95°
Toronto: 83° (28.3°C)
Washington, DC (DCA): 93°
June 11-19, 1957:
Boston: 95°
Burlington: 91°
Montreal: 91° (32.8°C)
New York City: 96°
Ottawa: 91° (32.8°C)
Philadelphia: 100°
Richmond: 96°
Toronto: 93° (33.9°C)
Washington, DC (DCA): 97°
June 8-13, 1967:
Boston: 92°
Burlington: 87°
Montreal: 83° (28.3°C)
New York City: 92°
Ottawa: 84° (28.9°C)
Philadelphia: 90°
Richmond: 93°
Toronto: 83° (28.3°C)
Washington, DC (DCA): 92°
Given that the timing of the 1953 and 1957 warm spells coincide better with the upcoming period, I believe the temperatures from those years are likely more representative of what lies ahead.
As a result, I believe one will likely see Boston, New York City, Newark, Philadelphia, Richmond, and Washington, DC all see one or more high temperatures of 90° or above. Newark, Philadelphia, Richmond, and Washington, DC have a chance to see a reading of 95° or above. The highest temperature will likely reach or exceed 85° (29.4°C) in Toronto and Burlington. Both Montreal and Ottawa will likely see at least one reading of 80° (26.7°C) or above. Newark, Richmond and Washington, DC could experience a heat wave.
All said, a taste of summer lies just ahead.