It is the mirage that we rarely see over water in the Northwest: an inferior mirage in which objects look much lower than they actually are.
In this blog I have frequently talked about summertime superior mirages over Puget Sound, in which warm air over cold water creates an atmospheric lens that makes objects near the water loom upwards in height. Here is an example of one provided to me by Skunk Bay weather cam master, Greg Johnson, in chich the coastal cliff's loom upwards.
But during the last few days, we have had the opposite situation in very cold air (15-25F) has moved over the relatively warm water of Puget Sound and adjacent waterways (all around 48-50°F). This warm water warms the air immediately above.
Cold air over warm produces a lens effect that results inferior mirages, in which objects are seen lower than they actually are (see schematic below).
A frequent example of an inferior mirage is on hot summer days, a very warm roads heat the adjacent air, with cooler air above. Light from the sky is bent down, giving the impression of water on the road, when it is actually light from the sky that provides the watery look (see below). Inferior mirages often invert objects as they push them downwards.
As noted earlier, today we had cool air above warm water. Furthermore, winds have been relatively light, which reduces mixing of air in the vertical. Greg Johnson, located on Skunk Bay of the northern Kitsap Peninsula took some excellent pictures this morning of inferior mirages. Here is a good example. The top of the light color cliffs are push downward, as is part of the ships bow (which is also inverted).
A close-up shows the action better.
In this blog I have frequently talked about summertime superior mirages over Puget Sound, in which warm air over cold water creates an atmospheric lens that makes objects near the water loom upwards in height. Here is an example of one provided to me by Skunk Bay weather cam master, Greg Johnson, in chich the coastal cliff's loom upwards.
But during the last few days, we have had the opposite situation in very cold air (15-25F) has moved over the relatively warm water of Puget Sound and adjacent waterways (all around 48-50°F). This warm water warms the air immediately above.
Cold air over warm produces a lens effect that results inferior mirages, in which objects are seen lower than they actually are (see schematic below).
A frequent example of an inferior mirage is on hot summer days, a very warm roads heat the adjacent air, with cooler air above. Light from the sky is bent down, giving the impression of water on the road, when it is actually light from the sky that provides the watery look (see below). Inferior mirages often invert objects as they push them downwards.
As noted earlier, today we had cool air above warm water. Furthermore, winds have been relatively light, which reduces mixing of air in the vertical. Greg Johnson, located on Skunk Bay of the northern Kitsap Peninsula took some excellent pictures this morning of inferior mirages. Here is a good example. The top of the light color cliffs are push downward, as is part of the ships bow (which is also inverted).
A close-up shows the action better.
An image of a ship (the Evergreen) shows a similar downward displacement and inversion of features.
Another "mirage" have been the suggestions of moderate snow over the Puget Sound lowlands. On Saturday, precipitation in some sea level locations will start as snow (Saturday evening), but will rapidly turn to rain.
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