The NOAA Storm Prediction Center’s Convective Outlook (graphic) from 1630 UTC 23 May 2020 shows an enhanced risk of Severe Thunderstorms in northern Illinois with a sharp cutoff in probabilities to the north in southern Wisconsin. The imagery above shows the GOES-16 ABI Band 2 (0.64 µm) visible imagery (click here for Band 13 (10.3 µm) Infrared Imagery), and it shows convection over northern Illinois/southern Wisconsin ahead of an obvious vorticity center in Iowa. How far north will the convection build?

This question can be answered by considering lower-tropospheric (900-700) and mid-tropospheric (850-500) lapse rates diagnosed from the NUCAPS Profiles produced from the NOAA-20 pass over the Upper Midwest at ~1818 UTC (NOAA-20 orbit for this day shown here); these data were available within AWIPS by 1915 UTC! 

The toggle below shows ABI Bands 2 and 13 (0.64 µm and 10.3 µm, respectively) as well as the lapse rates. The Lower Tropospheric lapse rates show a north-south gradient in stability, with air that is more stable over Wisconsin; convection over Illinois should weaken as it moves north. Mid-tropospheric lapse rates show a similar gradient in stability albeit less pronounced. (Click here to view the lower-tropospheric lapse rates overlain with NUCAPS sounding availability points from AWIPS, color-coded to show whether or not Infrared and/or microwave retrievals converged. Over southwest Wisconsin/northwest Illinois, perhaps you can argue that the gradient is influenced by soundings that did not converge; that argument would be harder to make over northcentral/northeast Illinois and southcentral/southeast Wisconsin).

This post is to remind you that satellite-derived retrieval data (independent of model data) is available in AWIPS in a timely manner to help you diagnose the thermodynamic state of the atmosphere. (Added: Storm reports for this event are here. Severe weather did cross into Wisconsin but was very close to the Illinois border).

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The thermal signature of a large nighttime fire at Pier 45 in San Francisco (media report) was evident in Shortwave Infrared (3.9 µm) images from GOES-17 (GOES-West) and GOES-16 (GOES-East) — the warmest 3.9 µm brightness temperature sensed by GOES-17 was 27.8ºC (at 1151 UTC), while the warmest temperature sensed by GOES-16 was only 14.2ºC (at 1146 UTC).

Note that a faint thermal signature of the fire (pixels exhibiting dim shades of white) was also apparent in GOES-17 Near-Infrared “Snow/Ice” (1.61 µm) and GOES-17 Near-Infrared “Cloud Particle Size” (2.24 µm) images. This is because those two ABI spectral bands are located close to the peak emitted radiance of very hot features such as volcanic eruptions or large fires (below).

Just after sunrise, the northward meandering of smoke could be seen in GOES-17 “Red” Visible (0.64 µm) images (below).

However, a larger-scale view of GOES-17 True Color Red-Green-Blue (RGB) images created using Geo2Grid (below) revealed that filaments of higher-altitude smoke were drifting southward, while the aforementioned low-latitude smoke was drifting more slowly northward.

A profile of 12 UTC rawinsonde data from Oakland (below) explained these differences in smoke transport — winds at higher altitudes were stronger, and had a northerly component.

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images with time-matched plots of SPC Storm Reports (above) showed the development of thunderstorms that produced tornadoes, large hail and damaging winds in parts of southwestern Oklahoma and far northern Texas on 22 May 2020. Of particular note was the 5.33-inch diameter hail that fell in Burkburnett, Texas — reported at 2340 UTC. A number of Above-Anvil Cirrus Plume (AACP) features were seen with these storms (VISIT training).

The corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images (below) revealed pulsing overshooting tops which exhibited cloud-top infrared brightness temperatures as cold as -80ºC (violet pixels). According to 20 UTC rawinsonde data from Fort Worth, Texas this temperature represented an overshoot of the Equilibrium Level of approximately 2 km.

1/n Regarding Friday’s Burkburnett, TX 5.33″ diameter #hail…(Photo: ToniRieScott/FB)

NOAA’s Storm Events Database documented 24 other 5″+ hail events in Texas since 1950.

The last one was almost exactly 1 year ago (5/20/2019) in Collingsworth County. pic.twitter.com/RFABUIlglQ

— Jonathan Erdman (@wxjerdman) May 24, 2020

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images with time-matched SPC Storm Reports (above) showed widespread thunderstorms that moved northward across the High Plains during the afternoon and evening hours on 20 May 2020. There were Above-Anvil Cirrus Plumes associated with many of these severe storms (VISIT training).

The corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images are shown below.

The overall spatial scale of this convective complex is also remarkable for Canada as it continues to migrate northwest.

All of this is via a very impressive late season -tilted trough spanning the Rockies. Convection will fuel sfc cyclogenesis downstream of the trough axis. https://t.co/mlE5XMApCJ pic.twitter.com/DzQBCXIt7b

— Philippe Papin (@pppapin) May 21, 2020

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