The High Plains of Kansas, Colorado, Oklahoma and Texas experienced a significant dust storm (with Dust Storm Warnings issued) on 15 January 2021, (Click here for a blog post on the blowing dust with this storm on 14 January) associated with a strong jet streak and extratropical cyclone discussed here. The animation above (Here’s the same animation, but slower) shows visible imagery along with GOES-16 Mesoscale Sector Derived Motion Winds from the Visible Channel. These derived winds are available with a 5-minute cadence, and the dust was thick enough that features could be tracked. There aren’t a lot of derived winds; how well do these derived winds compare to surface winds?

The image above, from 1900 UTC, shows Derived Motion winds along with METAR observations. Derived Motion winds are stronger than surface winds, as expected; compare, for example, the observations at Limon CO (KLIC) with the nearby derived wind vectors. The levels of the derived motion winds are between 800-820 hPa, away from the effects of friction/surface roughness. However, they do give a nice estimate of what surface winds might be in regions without surface observations, as apparent in the animation at the top.

It can be difficult to view dust with just one ABI channel such as the visible, especially when the sun is high(ish) in the sky and there is little forward scattering. Multi-spectral RGB products, such as the GOES-16 Dust RGB, shown below in a toggle with a VIIRS True-Color image and the GOES-16 Fire RGB (there is a fire evident near KLHX, LaJunta, CO), are a valuable tool in identifying the horizontal extent of dust plumes.  Dust is highlighted in the Dust RGB by a vivid pink/magenta color.

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GOES-16 (GOES-East) Upper-level Water Vapor (6.2 µm) images (above) displayed the signature of a leeside cold frontal gravity wave (reference) as it moved rapidly southward across the Plains (surface analyses) on 14 January 2021. Post-frontal wind gusts in the 50-70 knot range were seen, with a peak gust to 91 knots (105 mph) in eastern Wyoming.

In addition, an anomalously-strong (170-180 knot) meridional branch of the upper-tropospheric polar jet stream was progressing southward over the Rocky Mountains — and GOES-16 Water Vapor images with plots of Derived Motion Winds and contours of RAP40 model maximum wind speeds (below) revealed that the highest satellite-tracked Derived Motion Wind (DMW) speed was 182 knots over southern Montana at 1401 UTC. Some of the DMW speeds were nearly 10 knots faster than the RAP40 model maximum wind (for example, this 170-knot DMW over Wyoming at 1616 UTC).

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The CIMSS CSPP-Powered GeoSphere site is now available.  This site allows quick access to GOES-16 imagery via Cloud-friendly, flexible (and configurable) software.  Data are accessed from the GOES Re-Broadcast (GRB) downloaded via antenna at CIMSS/SSEC.  Significant effort was made to reduce latency.  For example,  GOES-16 Mesoscale Sectors load within about a minute of their being downloaded, CONUS sectors load within about 8 minutes, and Full-Disk imagery loads within 20 minutes.  In addition to the individual bands (1-16), a sharpened True-Color (Daytime) and Nighttime Microphysics (Nighttime) product is available.  The data are tiled and only tiles that are needed for the present view are loaded.  In addition to still images, animations can be displayed, and a user can choose how many images are in the loop (up to 30), and what the time-step (i.e., ‘Pattern Stride’) is.  Users can also share urls so that others can view the same animation.  For example, the image above was created with this url.  Individual frames can be downloaded via a left-click on the image.  There is at present no method to download animations directly.

More information on this site is available in this recorded presentation created from this PowerPoint.

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GOES-16 (GOES-East) Nighttime Microphysics RGB, Night Fog BTD (10.3-3.9 µm) and Cloud Thickness product (above) showed an arc of relatively thin fog across northern South Carolina, eastern North Carolina and southeastern Virginia — which was becoming thicker/deeper in time during the hours leading up to sunrise on 13 January 2021. In areas where the Cloud Thickness increased to 400 meters or more (lighter shades of cyan), freezing fog was observed at nearby METAR sites.

GOES-16 Nighttime Microphysics RGB images with plots of surface observations (below) indicated that air temperatures were near or just below freezing at most sites across the region.

The band of fog over eastern North Carolina and southeastern Virginia was being pushed eastward by a lower-tropospheric trough, as shown by the NAM40 model 925 hPa wind field at 12 UTC (below).

After sunrise, GOES-16 “Red” Visible (0.64 µm) images (below) showed that most of the fog quickly dissipated across southeastern Virginia and eastern North Carolina, while thicker fog persisted over much of South Carolina.

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