GOES-16 “Red” Visible (0.64 µm, top) and Shortwave Infrared (3.9 µm, bottom) images [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed the smoke plume and thermal anomaly or “hot spot” (cluster of darker black pixels) associated with what was likely a prescribed burn at or near the Brooklyn Wildlife Area in south-central Wisconsin on 19 October 2021.

A toggle between the GOES-16 Shortwave Infrared image at 2027 UTC and a background Google Maps image — as viewed using RealEarth (below) — further implicated Brooklyn Wildlife Area as the likely fire source region.

GOES-16 Shortwave Infrared (3.9 µm) image at 2027 UTC, along with a Google Maps background [click to enlarge]

GOES-16 True Color RGB images created using Geo2Grid (below) offered a clearer depiction of the smoke plume, as it eventually moved northeastward over the Madison metro area.

GOES-16 True Color images [click to play animated GIF | MP4]

As the smoke plume moved over the Space Science and Engineering Center at the University of Wisconsin – Madison, the aerosol layer was detected by a rooftop High Spectral Resolution Lidar — generally within the 2-4 km altitude range (below).

UW-SSEC rooftop lidar images [click to enlarge]

A few miles to the northeast, the ceilometer at Madison Dane County Regional Airport also detected the base of the smoke plume aloft (below). 

Plot of surface report data from Madison Dane County Regional Airport [click to enlarge]

Southwesterly surface wind gusts at Monroe (located about 20 miles southwest of the fire source region) were as high as 24 knots (28 mph) just before 19 UTC (below).

Plot of surface data from Monroe [click to enlarge]

Thanks to Kathy Strabala (SSEC) for bringing this case to our attention!

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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.

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The Storm Prediction Center in Norman issued a convective outlook on 12 October 2021 that included a large area of Enhanced Risk over western Kansas and Oklahoma, noting the expected development of a strong low-level jet creating favorable shear profiles for supercells. (SPC increased the threat to a Moderate Risk for a small part of southwestern Kansas and parts of the Oklahoma and Texas panhandles at 2000 UTC). The Band 10 low-level water vapor image above, from 1931 UTC. An initial round of convection is moving eastward over central Kansas. Did that convection stabilize the atmosphere? NUCAPS profiles can give information on that, information that is not dependent on numerical model simulations.

The plot below, taken from RealEarth, shows the Lifted Index computed from NUCAPS soundings blended with MADIS surface observations. The greatest instability, shaded in red, lies along the Kansas/Colorado border, and it extends to the southeast along the western Oklahoma/north Texas border. (Click here to see surface-based CAPE at the same time).

What do individual profiles show? 20 different profiles over southwestern Kansas are in the stepped animation below. Steep mid-level lapse rates (greater than 8 K/km) are indicated in the soundings, and Most Unstable Convective Available Potential Energy (MUCAPE) values persist in the lower troposphere. It also appears that moisture is pooling along the Kansas/Colorado border: precipitable water values from two soundings (at 38.42 N/102.60 N and 38.04 N /101.89 W) and are greater than surrounding values. So: instability is present, and moisture is available. Model-independent information like this can help a forecaster during the wait for initiation.

It can be time-consuming in AWIPS to look through multiple soundings (the Pop-up SkewT functionality can be helpful, but for subtle changes in precipitable water, or in lapse rate, that use is limited). Gridded NUCAPS fields are available in AWIPS, and also online. The 700-500 mb lapse rate, shown below, from this website, diagnoses the steep lapse rates that were present (perhaps to be expected given the suggestion of an elevated mixed layer in the water vapor imagery at the top of this blog post!)

So what happened with this event? Convection developed along the Colorado/Kansas border, and spawned severe weather over western Kansas, western Oklahoma, and western Texas. GOES-16 clean window infrared imagery (10.3 µm), below, shown on top of the Level 2 stability Lifted index product, shows the instability and the development of the convection (Click here for a Band 13 animation only).

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GOES-17 True Color RGB images [click to play animated GIF | MP4]

GOES-17 (GOES-West) True Color RGB images created using Geo2Grid (above) showed the transport of smoke from the Alisal Fire in Southern California on 12 October 2021. The dashed line in the images is Highway 101 — a portion of which was closed, as the wind-driven fire raced toward the coast. Late in the day some low-altitude smoke began to move eastward along the coast, eventually reducing the surface visibility to 6 miles at Santa Barbara.

During the preceding overnight hours (at 0916 UTC or 2:16 am PDT), a comparison of Suomi-NPP VIIRS Shortwave Infrared and Day/Night Band images (below) revealed the thermal signature and nighttime glow of the fire. The VIIRS imagery was downloaded and processed via the SSEC/CIMSS Direct Broadcast ground station.

Suomi-NPP VIIRS Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

The Suomi-NPP overpass time of the fire region was actually 0926 UTC — and a time-matched comparison of Shortwave Infrared images from GOES-17 and Suomi-NPP (below) demonstrated that the superior spatial resolution of VIIRS instrument (~375 meters, vs ~2 km for the ABI on GOES-17) provided a more accurate depiction of the areal coverage of the fire.

Shortwave Infrared images from Suomi-NPP (3.74 µm) and GOES-17 (3.9 µm) [click to enlarge]

===== 13 October Update =====

GOES-17 True Color RGB images [click to play animated GIF | MP4]

On 13 October, GOES-17 True Color RGB images (above) showed that as offshore wind speeds relaxed, a shift to onshore flow recirculated some of the smoke inland — with smoke briefly reducing the surface visibility to 1.5 miles at Santa Barbara airport (below). Farther to the south, residual smoke from the previous day of burning was also evident, with some of it traveling as far as Isla Guadalupe (Guadalupe Island) nearly 400 miles away.

Time series of surface observation data from Santa Barbara Municipal Airport [click to enlarge]

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