Surface Boundary Detection via Hybrid Water Vapor Imagery

Surface frontal boundaries moving south and west across the eastern plains of New Mexico are a welcome sight of moisture return to the area in many cases.  These boundaries are well known for producing strong east winds in the Rio Grande Valley as they surge west through gaps in the central mountain chain.  Timing onset of these gusty winds can be a challenge for the aviation forecaster producing a terminal aerodrome forecast at KABQ due to the low density of surface observations across much of eastern NM.  The animation below is an interesting case of how the surface boundary was well represented by the hybrid water vapor imagery.  The SPoRT default color curve was altered in AWIPS to a RAMSDIS color curve.  One can clearly see the sharp surface boundary pushing west toward KABQ May 14, 2011 at 0515 UTC.  This boundary represents a secondary surge of moisture into the Rio Grande Valley, hence another uptick in east wind intensity.  By overlaying the distance speed tool in AWIPS one can better anticipate this secondary surge of stronger winds.

Hybrid Water Vapor Loop valid May 14, 2011 0415 UTC - 0845 UTC. Click image to enlarge and animate.

Surface observations at KABQ were generally east southeast at 20 knots through roughly 07 UTC.  As the secondary boundary neared the station the wind shifted to the more traditional east direction with sustained winds near 25 knots and gusts to 32 knots.  The aviation warning criteria for KABQ is 35 knots so this was a close one.   The following two images are the base velocity from KABX valid at 0608 UTC and 0833 UTC from the NCDC archive.  Note the difference is east wind strength before and after the boundary passage.

KABX base velocity valid 0608 UTC. Green and blue colors represent east to southeast winds.

KABX base velocity valid 0833 UTC. Note the increase in wind speed by the presence of more light blue colors.

2 thoughts on “Surface Boundary Detection via Hybrid Water Vapor Imagery

  1. Brian,

    Great post. The animation with the green feature and timeline are very helpful. The 0515 UTC image with MODIS inserted as the proxy ABI-type imagery was able to nicely identify that moisture feature, which not as evident in GOES until about 0701 UTC A few quick questions. Was the timing of the event realized sooner due to the Hybrid imagery? Also, how often do mid-level features seen in the WV imagery translate into changes seen at the surface.

    Kevin Fuell

  2. Kevin,

    This is certainly not the first time we have noticed this type of low level feature on the water vapor imagery. The higher resolution hybrid image however caught my attention as to the location and thus improved the timing to some degree. Generally mid level features do not translate into changes at the surface, except for seldom surface reflection of mountain wave activity and the case mentioned above.

    Brian

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