The animation above shows NOAA-20 VIIRS true color imagery of Pyramid Lake (The Paiute tribe maintains a Pyramid Lake Twitter Account: Link)  in western Nevada. The Lake was closed on 21 July 2020 because cyanotoxins released during a toxic algae bloom (link). The algae bloom is apparent before the lake closure on 21 July, as shown, for example in this Sentinel-2 image.  The color change due to the algal bloom is obvious between 01 and 20 July, as shown below.

The algal bloom was followed by a ‘whiting’ event during which calcium carbonate precipitates into the water (link with description).  On 1 August (below), that suspended calcium carbonate is apparent in far southern Pyramid Lake (Here is an image from 2 August, and here are photographs of the Lake from 5 August).  The discoloration spreads slowly north, covering the entire lake by mid-August.   The animation above shows swirls in both algae and turquoise waters that are related to surface currents in the lake.  The shimmery turquoise color remains as of 3 September 2020.  Check out VIIRS today daily into the future to see how the color changes.

Hat tip to Mike Stavish, SOO at WFO MFR for alerting us to this event!

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1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed the dense smoke plume and thermal anomalies (clusters of yellow to red to black pixels) associated with the SQF Complex of wildfires that had been burning since 24 August. Also evident in the Visible imagery was the presence of brighter white pyrocumulus clouds that persisted for several hours over the source region of one of the hotter fires — in fact, this fire complex included the Castle Fire which produced a pyrocumulonimbus cloud on 23 August.

As the smoke drifted northward across the San Joaquin Valley, surface visibility at some locations such as Fresno (KFAT) was reduced to 5 miles.

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The Climate Prediction Center (CPC) Morphing (CMORPH) technique produces global estimates of hourly precipitation and those data are available in real time at this website. (Other JPSS/ABI-related flood products are available there as well). CMORPH uses microwave data from Polar Orbiters to estimate rainfall. Infrared information is related to those microwave data estimates, and those infrared data (from ABI, AHI, etc) are used to estimate precipitation during times when microwave observations are not present. This morphing technique is thus different from other morphing techniques for Total Precipitable Water (TPW) such as MIMIC that use model data to move quasi-conserved moisture fields to observational data voids. (Training on MIMIC TPW fields).

Hourly and Daily precipitation totals are available at the website. The animation above shows annual precipitation over the course of 6 days. Daily precipitation on 27 August, for example (link), shows the heavy rain accompanying land-falling Hurricane Laura. In the animation, the rains with that system move north to the mid-Mississippi River before being shunted eastward.

Hourly Precipitation, shown below from 12-15 UTC on 3 September 2020, allows for enhanced situational awareness with respect to heavy (or light) rains.

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1-minute Mesoscale Domain Sector GOES-17 (GOES-West) Shortwave Infrared (3.9 µm) images (above) showed a number of thermal anomalies — clusters of hot pixels, yellow to red enhancement — associated with wildfires that developed across parts of Montana on 02 September 2020. The SPC Fire Weather Outlook had highlighted critical to extreme fire weather conditions over much of that region, which included strong winds both ahead of and behind a cold front that was moving southward across Montana. As winds shifted to northerly in the wake of the cold frontal passage, visibility was reduced to 6 miles at Billings (KBIL) as smoke from a fire (located approximately 40 miles to the north) began to drift over that location.

A 4-panel comparison of GOES-17 “Red” Visible (0.64 µm), GOES-17 Shortwave Infrared, GOES-16 (GOES-East) Fire Power and GOES-17 Fire Temperature Red-Green-Blue (RGB) images (below) provided a closer view of the Huff Fire — which, fanned by northwest winds gusting as high as 59 mph, made a rapid run toward the southeast and prompted an evacuation of residents in Jordan.

A time-matched comparison of Shortwave Infrared images from Suomi NPP (overpass map) and GOES-17 at 2042 UTC is shown below. The higher spatial resolution of the VIIRS instrument on Suomi NPP (375 meters) more accurately detected the shape and areal extent of the fire at that time, compared to the 2 km spatial resolution (at the satellite subpoint) of the ABI instrument on GOES-17. Northwest winds were gusting to  knots (51 mph) at the Jordan airport.

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