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

On 5 April 2017, The Storm Prediction Center in Norman OK issued a Day 1 Convective Outlook that included Moderate and High Risk areas over much of the southeastern United States. Mesoscale discussion 442 and 448 on 5 April discuss the area shown above. One of two GOES-16 Mesoscale Sectors on 5 April viewed this scene, and a 2-hour animation spanning the outbreak of convection is shown above. It is difficult to predict which particular towering cumulus is going to grow into a cumulonimbus based on the visible imagery alone.

Water Vapor Imagery from GOES-16 might help in that prediction. The animation above, from 2000 UTC to 2130 UTC, shows multiple subtle gradients in the low-level water vapor field that could be associated with impulses influencing convective initiation. Convection appears to form along those subtle gradients. The 16 channels on ABI offer far more information than legacy GOES.

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CIMSS Scientists have been refining the NOAA/CIMSS ProbSevere product to account for individual threats (Hail, Wind, Tornado), and a screen capture of that product is shown below. Radar Objects are outlined in colors that relate to the Probability of a severe event. These outlines allow a forecaster to determine which cell is potentially most threatening based on the inputs into the determination of probability.

At 2130 UTC, shown above, a cell over Tennessee has the highest ProbTor probability; the readout (below) shows the variables that are used in computing all the hazard probabilities — ProbHail, ProbWind, and ProbTor (Not all variables are used for all products; for example, ProbTor does not use Satellite-derived growth rates; ‘PS‘ in the output is the value of the 2016 version of ProbSevere). ProbTor of 70% for the cell over Tennessee (compared to smaller values at nearby cells) suggests that particular cell deserves special attention from anyone monitoring the cell for development. The ProbTor for the warned cell in Alabama — a cell that produced Tennis Ball-sized hail near Heflin , showed a ProbTor value at this time of 43% — a larger value than for the storms on either side of it — again suggestive that it should be of most concern. Ten minutes later, at 2140 UTC, ProbTor for the Tennessee storm had dropped to 34%, and that of the Alabama storm had increased to 55%.

ProbTor will be one of the CIMSS products demonstrated at the Hazardous Weather Testbed in June and July this year.

Note: ProbSevere products are computed using legacy GOES imagery only. GOES-16 data can be incorporated into this tool only after the statistical model has been trained on GOES-16 data, and that has not yet happened; A GOES-16 version is planned for the 2018 convective season.

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

As discussed in more detail on the VISIT Meteorological Interpretation Blog, a small lake effect cloud plume formed over the southern portion  of the Great Salt Lake in northern Utah on 04 February 2017. A comparison of early morning Visible images from the GOES-15 (GOES-West), GOES-16 and GOES-13 (GOES-East) satellites (above; also available as an MP4 animation) showed the advantage of improved spatial and temporal resolution provided by the GOES-16 0.64 µm “Red visible” band for depicting the evolution of this feature (which was responsible for some brief inland snow showers). The images are displayed in the native projection of each satellite.

Several hours prior to the formation of the lake effect cloud band, the MODIS Sea Surface Temperature product (below) indicated that mid-lake water temperatures were as warm as 48ºF.

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

Widespread fog and stratus had developed across southern Alabama and western Georgia during the pre-dawn hours on 04 April 2017. After sunrise, a comparison of 1-minute interval GOES-16 and 15-30 minute interval GOES-13 visible imagery (above) demonstrated the advantage of more frequent scans to monitor the dissipation of fog and stratus. The improved spatial resolution of the GOES-16 0.64 µm “Red visible” band — 0.5 km at satellite sub-point, vs 1 km for GOES-13 — also aided in the detection of smaller-scale river valley fog features.

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

GOES-16 Lower-Level (7.3 µm),  Mid-Level (6.9 µm) and Upper-Level (6.2 µm) Water Vapor images (above; also available as an MP4 animation) revealed the circulation associated with a Hurricane Force low over the North Atlantic Ocean (centered southeast of Newfoundland, Canada) on 31 March 2017. Plotted along the left edge of each image panel are hourly surface wind barbs and wind gusts (red, in knots) for St. Johns to the north (plot | text) and Cape Race to the south (plot | text) — winds gusted to 66 knots or 76 mph at Cape Race, and 49 knots or 56 mph at St. Johns (where the winds pushed a surge of sea ice into the harbor).

In a comparison of GOES-16 0.5-km resolution Visible (0.64 µm) and 2-km resolution Water Vapor (6.9 µm) images (below), both lower- and middle-tropospheric structures of the storm could be seen. Plotted on the images are hourly surface wind barbs and wind gusts (red, in knots).

This storm had an interesting history of development. GOES-13 (GOES-East) Water Vapor (6.5 µm) images (below) showed that a southern storm — which was the subject of an Invest (AL90) for possible subtropical storm development — moved northward during the 28-30 March period, eventually merging with another storm that had moved offshore from the eastern US. During the day on 30 March, the sharp dry/moist gradient signature of a well-defined jet streak was then seen moving southeastward into the western edge of the merged system (1015 UTC image), providing energy for rapid intensification on 31 March (surface analyses).

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