Pre-frontal undular bores in western Texas

March 10th, 2017 |

GOES-16 Visible (0.64 µm) images, with hourly surface reports [click to play animation]

GOES-16 Visible (0.64 µm) images, with hourly surface reports [click to play animation]

** The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. **

GOES-16 Visible (0.64 µm) images (above; also available as an MP4 animation) showed multiple undular bores over western Texas on 10 March 2017. The wave packets were perturbing the low-altitude fog and stratus clouds across the region during the morning hours, in advance of a cold front that was approaching from the north. One bore was moving toward the south, while another (apparently deeper) bore was moving toward the southwest.

A plot of 12 UTC rawinsonde data from Midland (below) revealed the presence of a strong low-level temperature inversion from the surface to the 850 hPa  pressure level — this inversion was acting to duct the gravity waves as they propagated southward and southwestward.

12 UTC Midland, Texas rawinsonde data plot [click to enlarge]

12 UTC Midland, Texas rawinsonde data plot [click to enlarge]

Even though the undular bores were relatively shallow features, a subtle signature of the southwestward-moving bore was seen in Middle-Level Water Vapor (6.9 µm) and Lower-Tropospheric (7.3 µm) images (be1ow).

GOES-16 0.64 µm Visible (top), 6.9 µm Water Vapor (middle) and 7.4 µm Water Vapor (bottom) images [click to play animation]

GOES-16 0.64 µm Visible (top), 6.9 µm Water Vapor (middle) and 7.4 µm Water Vapor (bottom) images [click to play animation]

Leave a Reply