GOES-17 Fog/Low Stratus (FLS) product availability in AWIPS

October 18th, 2021 |

GOES-17 MVFR Probability over the PACUS Sector [click to play animation]

The suite of Fog/Low Stratus (FLS) products derived using GOES-17 (GOES-West) data within the PACUS Sector (above) became available via the Satellite Broadcast Network (SBN) for AWIPS on 18 October 2021. Two examples are shown below: one centered over Oregon, and the other centered over the Big Island of Hawai’i. The 4 products are Marginal Visual Flight Rules (MVFR, cloud ceiling 1000 to 3000 feet above ground level and/or visibility 3 to 5 miles) Probability, Instrument Flight Rules (IFR, cloud ceiling 500 feet to less than 1000 feet and/or visibility 1 to less than 3 miles) Probability, Low Instrument Flight Rules (LIFR, cloud ceiling less than 500 feet and/or visibility less than 1 mile) Probability and Cloud Thickness. 

GOES-17 MVFR Probability (top left), IFR Probability (top right), Low IFR Probability (bottom left) and Low Cloud Thickness (bottom right) [click to play animation]

GOES-17 MVFR Probability (top left), IFR Probability (top right), Low IFR Probability (bottom left) and Low Cloud Thickness (bottom right) [click to play animation] 

GOES-17 FLS products are also being produced by CIMSS over the Alaska region (below) — which are being distributed via an LDM feed.

GOES-17 MVFR Probability (top left), IFR Probability (top right), Low IFR Probability (bottom left) and Low Cloud Thickness (bottom right) [click to play animation]

A library of FLS applications can be found on the GOES-R Fog Product Examples site, and FLS Forecaster Training is available here.

River valley fog across the Mid-South

August 23rd, 2021 |

GOES-16 Night Fog BTD (10.3-3.9 µm) and “Red” Visible (0.64 µm) images, with and without plots of Ceiling/Visibility [click to play animation | MP4]

GOES-16 (GOES-East) Night Fog BTD (10.3-3.9 µm) and “Red” Visible (0.64 µm) images on 23 August 2021 (above) showed the nighttime formation of widespread river valley fog across parts of the Mid-South and adjacent Appalachians — followed by morning fog dissipation once solar heating initiated boundary layer mixing. With surface high pressure in place over the area, light winds helped to provide ideal conditions for strong radiational cooling and fog formation; note that the surface visibility was reduced to zero at a few sites in Tennessee. Much of that same region had recently experienced heavy rainfall (7-day accumulation | 7-day percent of normal), particularly in Tennessee as discussed in this blog post.

Suomi NPP VIIRS Day/Night Band (0.7 µm) images (below) displayed a subtle signature of some of the tendrils of river valley fog, and their growth during the ~90 minutes between the two satellite overpasses.

Suomi NPP VIIRS Day/Night Band (0.7 µm) images, with plots of Ceiling/Visibility [click to enlarge]   

Stratus and fog along the US East Coast

March 23rd, 2021 |

GOES-16 Cloud Thickness and

GOES-16 Cloud Thickness and “Red” Visible (0.64 µm) images, with plots of Ceiling and Visibility [click to play animation | MP4]

GOES-16 (GOES-East) nighttime Cloud Thickness and daytime “Red” Visible (0.64 µm) images (above) displayed a narrow band of marine stratus/fog that was moving southward along the East Coast of the US on 23 March 2021. Plots of Ceiling and Visibility showed that some sites along the coasts of New York, New Jersey and Delaware experienced a reduction in visibility to 1/4 mile at times. The Cloud Thickness product (a component of the Fog/Low Stratus suite) indicated that portions of this feature were 350-400 meters (1150-1300 feet) thick.

With ample illumination from the Moon — which was in the Waxing Gibbous phase, at 68% of Full — a NOAA-20 VIIRS Day/Night Band (0.7 µm) image at 0600 UTC or 2:00 am EDT (below) showed the stratus/fog feature as it was beginning to moved southward along the DelMarVa coast.

NOAA-20 VIIRS Day/Night Band (0.7 ) image [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) image [click to enlarge]

Freezing fog in the Carolinas and Virginia

January 13th, 2021 |

GOES-16 Nighttme Microphysics, Night Fog BTD (10.3-3.9 µm) and Cloud Thickness product [click to play animation | MP4]

GOES-16 Nighttime Microphysics RGB, Night Fog BTD (10.3-3.9 µm) and Cloud Thickness product [click to play animation | MP4]

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.

GOES-16 Nighttime Microphysics RGB images, with plots of surface observations [click to play animation | MP4]

GOES-16 Nighttime Microphysics RGB images, with plots of surface observations [click to play animation | MP4]

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).

GOES-16 Nighttime Microphysics RGB image, with a plot of NAM40 model 925 hPa winds at 12 UTC [click to enlarge]

GOES-16 Nighttime Microphysics RGB image, with a plot of NAM40 model 925 hPa winds at 12 UTC [click to enlarge]

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.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]