CIMSS Satellite Blog

Frequent images we obtain from #GOES16 show motion in the atmosphere nicely. Here’s a great loop of fog in the Strait this evening. #wawx http://pic.twitter.com/f0HI1yS8ab

— NWS Seattle (@NWSSeattle) May 21, 2017

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

As seen in a Tweet from NWS Seattle/Tacoma (above), a plume of fog/stratus moved rapidly eastward through the Strait of Juan de Fuca on 20 May 2017. A closer view of GOES-16 Visible (0.64 µm) images (below; also available as an MP4 animation) shows the formation of “bow shock waves” as the leading edge of the fog/stratus plume reached Whidbey Island at the far eastern end of the Strait near sunset — surface observations indicated that the visibility at Naval Air Station Whidbey Island was reduced to 0.5 mile just after the time of the final 0327 UTC image in the animation.

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

A Suomi NPP VIIRS Visible (0.6 µm) image with RTMA surface winds (below) showed that the wind speeds were around 15 knots at 21 UTC (just after the primary fog/stratus plume began to move into the western end of the Strait).

Suomi NPP VIIRS Visible (0.64 µm) images, with RTMA surface winds plotted in cyan [click to enlarge]

During the following nighttime hours, a Suomi NPP VIIRS infrared Brightness Temperature Difference (11.45 – 3.74 µm) “Fog/Stratus Product” image at 0910 UTC (below) revealed that the fog/stratus plume covered much of the Strait (especially along the Washington coast), and that the leading edge had begun to spread both northward and southward from Whidbey Island.

Suomi NPP VIIRS infrared Brightness Temperature Difference (11.45 – 3.74 µm) “Fog/Stratus Product” image, with RTMA surface winds plotted in cyan [click to enlarge]

Bill Line (NWS Pueblo) showed the nighttime fog/stratus monitoring capability of a GOES-16 infrared Brightness Temperature Difference product:

In the absence of visible imagery at night, evolution of fog is depicted well in #GOES16 fog difference. #wawx From: https://t.co/1tH0TQCKm3 http://pic.twitter.com/j6lMd4tDMa

— Bill Line (@bill_line) May 22, 2017

from CIMSS Satellite Blog http://ift.tt/2q4hnFW