An ice jam that developed on the Allegheny River at Parker (PA) New Year's
eve is beginning to make it's presence known.
The jam formed sometime during the night on New Years eve and caused the
river to rise from about 2.5 feet to nearly 10 feet by the early morning
hours on Jan 1st. Since then the jam has not moved and not rise in the
river was observed, that is, until Wednesday.
About 4:30 PM Jan 3rd, the jam began to break up underneath the Parker
bridge (st route 368) and moved a few hundred feet downstream. I observed
the break up from my residence and got in the car and drove to the shore
picking up some help along the way. When I reached the USGS gauge house I
noted a large rise in the water level and alos noticed that the Allegheny
river was flowing backwards! Ice chunks as big as large trailers were
moving upstream. I moved to a better vantage point (and high ground)
overlooking the boat launch about a quarter mile downstream, the jam was not
moving here. Apparently the ice that had broken up moved underneath the
rest of the jam which remained in place -- at least for the time being.
in 20 minutes the river had risen from 8.75 feet to 11.9 feet. The jam
began to move again and then stopped and the water backed up again. This
happened until about 7pm when the last movement was recorded. At 11:00 PM,
the river level was about 12.5 feet and seemed to be holding. However, it
can be noted that the river is not flowing at this point and is pooling as
there are free floating chunks of ice that are not moving and have not moved
since 10:30 PM. Therefore, there appears to be just enough water flowing
underneath the ice to keep the "pool" from draining or rising significantly.
Eyewitness reports say that about a mile south of Parker, near the mouth of
Bear Creek, the ice is packed so tight the chucks are nearly vertical and
are beginning to stack on top of one another creating beautiful (but
dangerous) mounds of ice in the river.
Ice jams are also reported on the river at East Brady, Foxburg, Emlenton,
Franklin and Oil City. It is unknown whether any of these jams shifted
today.
Jonathan Anschutz
Skywarn Spotter - Firefighter
Parker City PA
http://www.angelfire.com/pa/ParkerCityFire/page3.html - Parker City Weather
Center
[Non-text portions of this message have been removed]
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