In some instances, however, the cold pool is incredibly shallow. As such, it might be better labeled a cold puddle. One could observe lingering pollution in such a cold puddle yesterday afternoon over the Great Salt Lake and and lower elevations of the northern Salt Lake Valley.
Pollution in an extremely shallow cold pool (a.k.a. cold puddle) over the Great Salt Lake and lower elevations of the northern Salt Lake Valley at about 5 PM MST 28 Nov 2012 (click to enlarge) |
Source: MesoWest |
What is happening here is that an extremely shallow puddle of cold air remained entrenched over the Great Salt Lake. That cold air eventually pushed southward and eastward into the Salt Lake Valley with the Great Salt Lake breeze yesterday afternoon. The temperature contrast accompanying the Great Salt Lake breeze was greatly concentrated thanks to the warm southerly flow ahead of it.
The Salt Lake City Airport and areas to the west can sometimes feel like another planet compared to the University of Utah and the east bench, and that was the case late yesterday afternoon.
I think this case highlights some very interesting patterns. Based on surface temperatures, the Salt Lake and Tooele valleys usually appear to have some of the deepest mixing of anywhere in the state once the surface cold pool is pushed out. SLC has been even warmer than St. George much of the last 24 hours, essentially dry adiabatic to 700 mb which most of the state has not been, at least until now. Most of the I-15 corridor in general (Ogden to Cedar City), also seems to mix out fairly readily in southerly wind patterns. Further west in the Salt Lake Basin, mixing was much poorer. The area around Wendover barely warmed above 40 degrees yesterday, and was 32 last night while SLC was 56. The station at Lakeside Mountain, west of the lake at just over 5,000 feet has remained in the 40s, implying that the cold puddle is somewhat deeper on that side of the basin. Fascinating stuff!
ReplyDeleteI didn't mean to imply that 56 was the low temp at SLC... that was from the ob last evening around 10 pm.
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