Scud clouds are likely the culprit
Did you notice the skies around the greater Syracuse area Thursday at around 6:00 PM? I had just finished dinner when I looked outside my window and noticed the skies looked a bit ominous. Looking westbound towards the area just south of the city of Syracuse, I noticed suspicious skies forming. I quickly picked up my camera and took the pictures you see in the slide show. These pictures were taken between 5:55pm and 6:05pm on Thursday. Was I witnessing a wall cloud forming? Was that a funnel cloud dropping down from the wall cloud? Was I seeing a tornado forming in front of my eyes? I quickly called Wayne Mahar and alerted him of the skies that I had seen. My wife helped out by e-mailing Wayne 3 of these pictures and then I snapped more shots.
We both looked at Live Triple Doppler Radar and agreed that the thunderstorm producing this cell was not overly impressive. Yes, there was some heavy rain & some wind, but there was little if any rotation. Still, there was a lot of wind energy aloft, so I could not be completely certain of what I was seeing. Wayne told people on the air that there were “suspicious skies” just south of Syracuse and that a brief heavier thunderstorm was passing through. I decided to post these pictures on my twitter site and called the National Weather Service in Binghamton for their opinion. After looking at these pictures, they came to the following conclusion and sent me this e-mail below:
Peter,
We (3 of us here) looked at the pictures and came to the conclusion that it was basically low hanging scud clouds underneath the parent cloud formation. The problem with this is that we cannot see any rotation (always hard to do with stills). However, if you get any information from your viewers who saw it and got it on video, that would give you (and us) a better idea if there was any rotation.
Thanks for sending the pictures...
So what is a scud cloud?
A scud cloud is defined as low ragged and wind-torn clouds appearing as fragments, usually not attached to the thunderstorm base, often seen in association with, and behind gust fronts. Scud clouds do not produce severe weather. Scud clouds are often mistaken for wall clouds and tornadoes, especially when attached to the thunderstorm base. A way to differentiate scud clouds from wall clouds is to watch their relative position with respect to the rain area: Scud clouds move away from the rain area while wall clouds maintain the same relative distance. Additional definitions found from here declare: Scud clouds, a type of fractus cloud, are low, detached, irregular clouds found beneath cumulonimbus clouds. These clouds are often ragged or wispy in appearance. When caught in the outflow (downdraft) beneath a thunderstorm, scud clouds will often move faster than the storm clouds themselves. When in an inflow (updraft) area, scud clouds tend to rise and may exhibit lateral movement ranging from very little to substantial.
Scud clouds are formed as the cooler (and often more moist) downdraft of a thunderstorm lifts the relatively warm air near the surface. These clouds condense as the warm, moist air saturates through ascent and is pushed outward from the storm. Scud clouds are very commonly found on the leading edge of a storm front. In this area of a storm, scud are commonly associated with shelf clouds.
Scud clouds may also form when an updraft ingests precipitation-cooled air from the updraft. Scud forming in this region of the storm, if moving laterally, will tend to move inward towards the dominant updraft. Rising scud may condense and organize into a wall cloud.
Scud clouds can often be mistaken for a developing tornado, landspout, or waterspout. The difference is determinable by identifying if there's any rotation (not just movement) of the scud clouds. If any rotation occurs, a tornado, landspout, or waterspout has a high chance of forming.
Anyway, it was very exciting to see this cloud formation yesterday evening. Did you see this suspicious cloud? If so, e-mail us your pictures or video to news@cnycentral.com or weather@cnycentral.com or by sharing them at MyCNYcentral.
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