Major Severe Weather Outbreak
The first true summer like air mass of the season migrated into the Northeast over the weekend preceding this severe weather outbreak. Temperatures climbed into the 80s and dewpoint temperatures (dewpoints represent the amount of moisture in the air) climbed into the low 60s by Sunday the 5th. A backdoor cold front (A front that slips down the eastern New England coast, bringing chilly marine air into the Northeast from an easterly direction) moved into western New England and stalled by the early morning of Monday the 6th. The chilly air to the east of the front (temperatures in the 50s at Boston) contrasting with the very warm and humid air over eastern New York, caused the pressure gradient to increase over eastern New York and western New England resulting in the development of a strong south to southeast flow of air over the region. The strengthening flow served to increase the warmth and especially the moisture west of the front over the Hudson valley and Capital Region, while locking in the colder air to the east of the front in New England. Temperatures soared into the upper 80s with dewpoint temperatures rising to between 65 and 70 degrees. A moderate wind flow existed aloft out of the west creating a favorable wind shear environment, supportive of severe thunderstorms, and providing the trigger mechanism to set them off.
Severe weather with this event broke out in two parts.
Part I was composed of rather isolated supercell type severe t-storms that formed in a broken line extending from the Adirondacks south into Saratoga county. A tornado warning was issued on the Saratoga county storm at 1:14pm as rotation was evident on Doppler radar. The storm produced wind damage but no tornado. These scattered t-storms developed early in the afternoon out ahead of the main event that composed part II, and the more significant part of the outbreak.
The trigger for the main event appeared to be a mid level circulation left over from a complex of t-storms the day before over the Midwest. T-storms initiated on this mid level swirl over western Pennsylvania during the morning and intensified into a highly organized complex that accelerated east sweeping through every county in eastern New York and western New England during the mid to late afternoon hours. The t-storm complex produced widespread damaging straight line winds and frequent lightning. Wind damage with the squall line was reported in every county in the WRGB coverage area as it moved through. Rainfall was torrential, but only lasted a short time at any one location as the system was moving at between 30 and 40 mph to the east-northeast. Therefore rainfall amounts generally averaged less than 1/2" in most locations and flooding did not occur. The only exceptions to the lighter rainfall amounts were the few communities in the Adirondacks and into Saratoga, Schoharie, and Washington counties that were affected by the scattered T-Storms from round #1. In those locations, such as Wilton, and Mechanicville in Saratoga county, Jefferson in Schoharie county, and Lake Luzerne in Warren county, rainfall amounts averaged 1"-2".
The squall line was a prolific lightning producer. A few of the stronger cells within the main squall line at its height produced up to 400 lightning strikes per minute. A severe T-storm watch was initially issued by the Storm Prediction Center to cover this event but was upgraded to a tornado watch which was in effect until early in the evening. No tornadoes, however, were found to have occurred with this outbreak of severe t-storms.
The table lists the reported severe weather occurrences and damage for the June 6, 2005 severe weather outbreak