Moisture advancing east in pre-convective Wyoming environment

 Simulated GeoXO Imager (GXI) imagery revealed the westward extent of higher moisture in the pre-convective environment of eastern Wyoming this afternoon.

Figure 1 shows the water vapor transmittance (WVT, derived from the 0.91 µm channel) in the left panel and the 5.15 µm brightness temperature in the right panel over a five hour period from 16-20 UTC..  A dashed green line indicates the approximate westward extent of the deeper moisture as estimated from the WVT imagery. In this “inverted” color scheme, drier areas appear darker in WVT (as does higher terrain), and moister areas appear whiter; high-topped clouds generally appear dark.  In the last frame of the loop, convection initiates near Douglas along this moisture boundary on the southern end of this green line.

While WVT is sensitive to the total column water vapor, the 5.15 µm channel is only sensitive to water vapor in lower levels, where lower brightness temperatures generally coincide with higher low-level moisture.  It is interesting to note that the WVT and 5.15 µm gradients do not always align with each other, possibly suggesting an evolving vertical distribution of water vapor.  Our future plans include developing methods to utilize these differences to derive information about depth of moisture in the column.

Figure 1: WVT (left panel; inverted color scale so whiter colors=more moist). The green dashed line indicates the approximate westward extent of deeper moisture as estimated from WVT. 

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