Severe Weather hit Louisiana on Tuesday 7 February 2017, and the ABI on GOES-16 viewed the convective development. This website includes an animation (also available on YouTube) of the visible imagery (Band 2, 0.64 µm with 0.5-km resolution at the subsatellite point) from ABI during the time period of the strongest tornadoes in and near New Orleans. Click here for an animation that includes views of all 16 ABI Bands.

A comparison of GOES-13 (GOES-East) Visible (0.63 µm) and Infrared Window (10.7 µm) images is shown below, with hourly surface reports and locations of the tornado reports.

Suomi NPP overflew the convection shortly after the tornadoes were on the ground in Louisiana, and images from the three spectral bands shown below, 11.45 µm, 0.64 µm and 1.61 µm show a mature convective system with overshooting tops over the Gulf Coast states and the Gulf of Mexico. The 1.61 µm Snow Ice band helps in the discrimination between cloud tops comprised of water droplets (bright white) vs. cloud tops comprised of ice crystals (grey); the ABI on GOES-16 has a similar band.

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A Shamal Wind event affected the Persian Gulf and the Arabian Peninsula during the first few days of February 2017, as a strong cold front moved southward across the region. Daily composites of Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images (source: RealEarth) during the 31 January – 05 February period (above) showed blowing dust eventually moving off the coast of Yemen and Oman and across the Gulf of Aden and the Arabian Sea (note the cold frontal arc clouds on 03 February). The strong Shamal winds on 03 February forced a suspension in the Dubai Desert Classic golf tournament the cancellation of Stage 4 of the Tour of Dubai bicycle race (Dubai meteorogram).

The cold air associated with the Shamal wind was especially evident at locations along the Persian Gulf during the 01-04 February period (below) — for example, the daily maximum temperature at  Abu Dhabi in the United Arab Emirates on 01 February was 31ºC (88ºF), while it was only 18ºC (64ºF) on 03 February. At Doha in Qatar, their minimum temperature was 9ºC (48ºF) — their all-time minimum is 4ºC (39ºF). Snow fell in the Oman / United Arab Emirates border lands, with 10 cm (3.9 inches) reported at Jabal Jais. In addition to Abu Dhabi, blowing dust/sand also restricted surface visibility to 2 miles or less at locations such as Abumusa Island and Fujairah.

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The red is where the fog is the thickest, with near zero visibility. Very dangerous driving conditions, only drive if necessary #TuleFog pic.twitter.com/yl9wORdJO6

— NWS Hanford (@NWSHanford) January 31, 2017

The tweet shown above was issued by the NWS forecast office in Hanford, California — using an image of the GOES-15 Low Instrument Flight Rules (LIFR) Probability, a component of the GOES-R Fog/low stratus suite of products — to illustrate where areas of dense Tule fog persisted into the morning hours on 31 January 2017.

AWIPS II images of the GOES-15 Marginal Visual Flight Rules (MVFR) product (below) showed the increase in areal coverage of Tule fog beginning at 0600 UTC (10 pm local time on 30 January); the fog eventually dissipated by 2030 UTC (12:30 pm local time) on 31 January. Note that Lemoore Naval Air Station (identifier KNLC) reported freezing fog at 14 UTC (their surface air temperature had dropped to 31º F that hour). In addition, some of the higher MVFR Probability values were seen farther to the north, along the Interstate 5 corridor between Stockton (KSCK) and Sacramento (KSAC) — numerous traffic accidents and school delays were attributed to the Tule fog on this day.

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Legacy infrared Brightness Temperature Difference (BTD) products are limited in their ability to accurately detect fog/low stratus features if high-level cirrus clouds are present overhead. This is demonstrated in comparisons of GOES-15 MVFR Probability and BTD products from Aqua MODIS (above) and Suomi NPP VIIRS (below). Again, note the Interstate-5 corridor between Stockton and Sacramento, where the extent of the fog was not well-depicted on the BTD images (even using high spatial resolution polar-orbiter MODIS and VIIRS data).

Daylight images of GOES-15 Visible (0.63 µm) data (below) showed the dissipation of the Tule fog during the 1600-2200 UTC (8 am – 2 pm local time) period. The brighter white snow pack in the higher elevations of the Sierra Nevada was also very evident in the upper right portion of the satellite scene.

One ingredient contributing to this Tule fog event was moist soil, from precipitation (as much as 150-200% of normal at some locations in the Central Valley) that had been received during the previous 14-day period (below).

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The Japanese Meteorological Agency (JMA) has released the first imagery from the Advanced Himawari Imager (AHI) on Himawari-9. The image above, from 0240 UTC on 24 January 2017, is from Band 3 (the “Red” Band) that detects reflected solar radiation near 0.64 µm in the visible part of the electromagnetic spectrum. This band has the highest spatial resolution of the 16 AHI channels: 0.5 km at the sub-satellite point. (A similar image from Himawari-8 at 0250 UTC on 24 January 2017 is here; Himawari-8 does not produce imagery at 0240 UTC or 1440 UTC; satellite housekeeping occurs at those times).

Additional Himawari-9 band imagery from 0240 UTC on 24 January 2017 is available here. All imagery courtesy of JMA.

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