GOES-16 (GOES-East) Shortwave Infrared (3.9 µm) images (above) showed the thermal anomaly (cluster of darker red pixels) associated with a fire at a metal recycling plant in La Crosse, Wisconsin — located at the center of the images — on 02 April 2021. According to media reports, over 100 vehicles were burning at the facility. Farther to the south, a few thermal signatures of prescribed burns were seen in northeastern Iowa.

A brief smoke plume was produced by the recycling center fire, as shown in GOES-16 True Color RGB images (below), which drifted north-northeastward. Smoke plumes from the prescribed burns were also evident.

A time series plot of surface weather conditions at La Crosse Regional Airport (below) showed the strong southerly winds gusting to 27 knots around the time of the fire, which transported the smoke plumes northward.

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VIIRS data from the ascending NOAA-20 overpass on 2 April 2021 — with data downloaded at the Direct Broadcast site at UW-Madison — showed predominantly clear skies over the Great Lakes.  Lake ice is confined to bays on the north shore of Lake Superior, and a hint of green appears over southeastern Pennsylvania and southwestern Ohio.  A larger version of this image is available here, for about a week.  VIIRS imagery is routinely available from all recent overpasses and can be viewed here.

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The animation above shows Himawari full-disk imagery from 2300 UTC on 1 April through 1140 UTC on 2 April and depicts a cluster of thunderstorms over the Pacific Ocean far to the northeast of Guam.  A particular challenge in diagnosing atmospheric events over the open Pacific is the lack of data.  In this case, a timely NOAA-20 overpass (around 0300 UTC), below, allowed for the use of NOAA-Unique Combined Atmospheric Processing System (NUCAPS) profiles to describe the atmosphere in and around this ongoing convection.

The toggles below shows Total totals index and Tropopause heights over the Pacific Ocean around Guam and northeastward over the developing convection.  Modest instability surrounds the convective cluster (TT values from 40-44);  somewhat more unstable air (TT > 46) is diagnosed to the northwest of the convection.   Tropopause heights surrounding the convection are high, around 200 mb.  Much lower tropopause heights are diagnosed over the northern part of the domain, and the more unstable TT values are in a region where the tropopause height is sloping.

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NUCAPS can also show you lapse rates within the atmosphere.  It is important when viewing lapse rates to consider that the vertical resolution of NUCAPS profiles is typically not greater than 10 layers within the tropopause.  The toggle above shows lapse rates from 925-700 mb; lapse rates from 850-500 mb are shown below. These domains are is a bit larger than the domain used in showing the tropopause height and Total Totals index above.  The 925-700 mb lapse rates show two regions:  relatively weak stability, with lapse rates around 5 or 6 C/km south of 30 N Latitude, and much stronger stability (Lapse rates closer to 3 C / km ) north of that latitude, to the east of Japan.

The 850-500 mb lapse rates similarly show two general regions:  not as stable south of 30 N, much more stable east of Japan.  There is a more concentrated region of lower stability, however, along the leading edge of the sloped tropopause, at 850-500 mb compared to 925-700 mb, and the 850-500 mb values show larger lapse rates in the air to the east of Japan.  This toggle shows the 925-700 and 850-500 mb lapse rates directly.

 

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This region of the Pacific Ocean is scanned by both the Advanced Himawari Imager (AHI) on JMA’s Himawari-8 satellite and the similar Advanced Meteorological Imager (AMI) on KMA’s GK2A satellite.  The animation below combines visible imagery from the two satellites at 0100, 0110, 0230 and 0400 UTC to create a pseudostereocopic image of the convection.

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Developing (and ongoing) thunderstorms are usually locations of turbulence. The CIMSS Turbulence product, shown below for the region from 0000 UTC to 0350 UTC, and available online here, does show elevated turbulence probabilities over the convection (located over the western part of the domain shown below).

Himawari-8 imagery in this blog post courtesy of JMA; GK2A imagery in the blog post courtesy of KMA. Thanks to Brandon Aydlett, WFO Guam, for alerting us to this interesting case.

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GOES-16 sea-surface temperatures on 1 April 2021 show a region of much cooler temperatures — values around 74ºF , green in the color enhancement used) — surrounded by warmer sea-surface temperatures (values in the mid-80sºF, yellows and oranges in the color enhancement) to the southwest of Nicaragua. Why does this cool region exist? Typically, cool ocean surface temperatures can originate via upwelling (Note in the image above cool temperatures along the Equator where persistent upwelling exists). Is the part of the ocean that is cool above affected by upwelling? Cool temperatures are apparent to the northwest as a result of oceanic upwelling from a Tehuano wind through the Chivela mountain pass (similar to this event from 2018). There is a similar gap in the mountains between Costa Rica and Nicaragua (link).  Perhaps a persistent wind through that gap during the past months initiated this cool patch.  As shown below, the cool patch has been quite persistent — it was apparent in mid-January.

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