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

High Dewpoints in mid-Summer in the Upper Midwest often leads to stratus and fog over Lake Superior. Such was the case on 10 July 2017, with dewpoints in the 50s and 60s F (GOES-16 Visible images with surface observations) and mid-lake water temperatures as cold as 40º F (buoy reports | MODIS SST values) — and very interesting waves were observed in the stratus deck. They had the appearance of Atmospheric Bores: parallel lines of clouds moving in one direction. It is unusual to have Bores moving in different directions at the same time, however.

One possible explanation for the differing motion of these undular bores could be internal reflection off the rugged northern and southern shorelines of Lake Superior.

The RTMA surface wind analyses at 17 UTC and 19 UTC, below, showed complex flow patterns over the lake — however, the surface wind flow did not always correspond well to the motion of the undular bores.

(Thanks to TJ Turnage, the SOO in Grand Rapids MI, for alerting us to this mesmerizing event).

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

Very heavy rain (4-5″) fell over parts of southwestern Wisconsin early on 10 July 2017 as a Mesoscale Convective System traversed the Upper Midwest (0831 UTC VIIRS Infrared vs Day/Night Band). The animation above blends the Clean Window (10.3 µm) from GOES-16 with the Total Precipitable Water Baseline Product (This product is available online — with a time delay — here). Note that the largest values of Precipitable Water are diagnosed to be over southern and western of Wisconsin. Looking at the animation of the 10.3 µm imagery, can you decide where the heaviest rain fell?

A screen capture from this website, below, shows 24-hour precipitation over the Upper Midwest, with a northwest-to-southeast oriented maximum near the northwest-to-southeast gradient of diagnosed total precipitable water field shown in the animation above. (This summary from the National Weather Service in Milwaukee shows accumulated precipitation ending at 0900 Central Time).

The Hazardous Weather Testbed at the Storm Prediction Center evaluates GOES-16 (and other satellites, such as Suomi NPP) products. There have been many instances that noted convection was most intense along the gradient of the moisture (See this summary, for example, or this one.) When GOES-16 Baseline Products indicate a gradient, pay close attention when strong convection develops upstream.

Added: One day later, again, convection initiated (and/or persisted) north of the diagnosed Total Precipitable Water maximum over Illinois and Iowa (link), i.e., in the gradient of Total Precipitable Water.

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

As southern California experienced a record-setting heatwave, 2 large wildfires were burning in San Luis Obispo and Santa Barbara counties on 08 July 2017: the Alamo Fire and the Whittier Fire. GOES-16 “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed the smoke plumes and hot spots (red pixels) associated with these 2 fires.

The dense smoke plumes also exhibited a signature on the Near-Infrared “Cirrus” (1.37 µm) images (below), even though they were not composed of ice crystals (note that 10.3 µm Infrared Window brightness temperatures of the smoke plumes were warmer than -20º C, cyan color enhancement, the entire day). This example demonstrates that in a dry atmosphere, the “Cirrus” imagery will also be able to detect the presence of any airborne particles that are efficient scatterers of light (which includes smoke, dust and volcanic ash).

During  the nighttime prior to sunrise, with the benefit of ample illumination from a Full Moon, a long smoke plume streaming southwestward from the Alamo Fire was clearly seen on Suomi NPP VIIRS Day/Night Band (0.7 µm) imagery at 0910 UTC or 2:10 am local time (below). A very bright glow — larger than that of some nearby city lights — was co-located with the large hot spot on the corresponding Shortwave Infrared (3.74 µm) image.

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

The San Francisco Bay Area National Weather Service office Tweeted out an image (as noted by the Media) during the early morning of 7 July of the GOES-16 Fire Temperature, a GOES-16 Baseline Product (link) above a massive fire in Oakland (News Report). The animation above shows the evolution of the fire as detected by the 3.9 µm Brightness Temperature shown in AWIPS. The first indication of a fire appeared around 1200 UTC; the fire was difficult to discern after 1330 UTC.

GOES-16 Baseline Products include Fire-Detection products: Fire Temperature, Fire Power, and Fire Area. These products returned values from 1222 to 1247 UTC, when the fire was at its most intense. The table below shows the values as noted in AWIPS.  The fire peaked in terms of Power and Area at 1237 UTC.  The animation below is for Fire Temperature, and only one area is indicated (Fire Power and Fire Area caused the same region to show a non-zero values, the same values noted in the table below). GOES-16 Engineers and Scientists are investigating why the pixel size below does not match the correct pixel sizes above in the 3.9 µm imagery.

Time	Fire Temperature (K)	Fire Power	Fire Area (Square Meters)
1222 UTC	892 K	86	4000
1227 UTC	873 K	92	4000
1232 UTC	849 K	153	4671
1237 UTC	833 K	167	5402
1242 UTC	889 K	137	4000
1247 UTC	1041 K	94	4000

 

The fire was hot enough that it emitted detectable near-infrared 1.61 µm radiation, as shown below (animation). The brightest pixel, pointed to by the red arrow, over downtown Oakland in Alameda County (outlined in magenta) shows an albedo of 4.2% before sunrise!

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