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Calf Canyon Fire produces a pyrocumulonimbus cloud

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.35 µm) and Cloud Top Temperature derived product images (above) showed that the northern portion of the Calf Canyon Fire/Hermits Peak Fire in New Mexico produced a pyrocumulonimbus (pyroCb) cloud on 10 May 2022. Extreme fire behavior was aided by surface wind gusts in the 42-64 mph... Read More

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), Infrared Window (10.35 µm, bottom left) and Cloud Top Temperature derived product (bottom right) [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.35 µm) and Cloud Top Temperature derived product images (above) showed that the northern portion of the Calf Canyon Fire/Hermits Peak Fire in New Mexico produced a pyrocumulonimbus (pyroCb) cloud on 10 May 2022. Extreme fire behavior was aided by surface wind gusts in the 42-64 mph range and very dry air within the boundary layer (along with very dry fuels from the ongoing drought); these large fires also burned very hot, with 3.9 µm Shortwave Infrared brightness temperatures reaching 138.71ºC — the saturation temperature of ABI Band 7 detectors. Coldest 10.35 µm cloud-top brightness temperatures exhibited by the pyroCb cloud were around -45ºC (lighter blue enhancement), with the Cloud Top Temperature product showing values as cold as -54ºC (red pixels).

In a comparison of NOAA-20 VIIRS True Color RGB, False Color RGB and Infrared Window (11.45 µm) images valid at 2057 UTC (below), the coldest cloud-top infrared brightness temperature was -59ºC. These images were acquired and processed using the Direct Broadcast ground station at SSEC/CIMSS.

NOAA-20 VIIRS True Color RGB, False Color RGB and Infrared Window (11.45 µm) images [click to enlarge]

During the preceding nighttime hours, a toggle between Suomi-NPP VIIRS Day/Night Band and Shortwave Infrared images valid at 0847 UTC or 2:47 am MDT (below) showed the bright emitted light and hot thermal signature of active fires along the periphery of the burn area — especially along the northern fire front, which eventually produced the pyroCb cloud.

Suomi-NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

An evolution of the recent New Mexico wildfires using a series of VIIRS Day/Night Band images is available at this blog post.

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Day Night Band Imagery of fires in New Mexico

The Day Night Band on the VIIRS sensor that flies on both Suomi NPP and NOAA-20 will view emitted light (or reflected moonlight) at night. The animation above (derived from imagery at the VIIRS Today website — from this sector, specifically) shows the light emissions from cities in New Mexico (click here to see the annotated first image... Read More

The Day Night Band on the VIIRS sensor that flies on both Suomi NPP and NOAA-20 will view emitted light (or reflected moonlight) at night. The animation above (derived from imagery at the VIIRS Today website — from this sector, specifically) shows the light emissions from cities in New Mexico (click here to see the annotated first image with place names), and, notably, fires. Multiple fires are apparent in the animation. For example: the Calf Canyon (start on 19 April)/Hermits Peak (start on 6 April) fire start in the center of the animation; to the northeast of that fire, the Cooks Peak fire that started on 17 April is mostly contained as of 10 May; the Cerro Pelado fire (start on 19 April) to the west of Santa Fe is also apparent.

Suomi NPP Day Night Band imagery on 10 May 2022. Note the 3 faint smoke plumes emitted from the Calf Canyon and Hermits Peak fires. The moon had set by the time Suomi NPP overflew New Mexico.

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Bolt out of the blue

Florida is one of the lightning capitals of the world, so residents need to be constantly aware of lightning safety. NOAA/CIMSS LightningCast might be able to help with that. A tree and home in Sebring, Florida were suddenly struck by lightning on the morning of Saturday, May 7th. A line of storms was... Read More

Florida is one of the lightning capitals of the world, so residents need to be constantly aware of lightning safety. NOAA/CIMSS LightningCast might be able to help with that.

A tree and home in Sebring, Florida were suddenly struck by lightning on the morning of Saturday, May 7th. A line of storms was edging its way eastward. A neighbor who was outside at the time said, “It wasn’t raining. It was nice and warm. It was cloudy, but that was it. And then boom!” This underscores how easy it is to be caught unaware of potential lightning danger.

LightningCast can help with users’ situational awareness. LightningCast is an experimental deep-learning model trained on thousands of GOES-R ABI and GLM images to predict the probability of next-hour lightning occurrence. In the animation below, the red dot is Sebring, Florida.

LightningCast probability contours, GOES-16 ABI imagery (grayscale background), and GOES-16 GLM flash-extent density (shaded color). The red dot is the approximate location of the “bolt out of the blue”.
Florida homeowner stunned by nearby lightning strike. Credit: FOX13 Tampa Bay

Below is a time series of LightningCast probability and GLM observations around the home in Sebring. Lightning struck the tree and home at 8:21 EDT, marked by the vertical black line below. You can see a rapid increase in probability of lightning from 11:26 to 11:36 UTC (7:26 to 7:36 EDT), reaching 70%. This was about 25 minutes before the first nearby lightning strike and 45 minutes before the Sebring home was struck.

The animation below from the National Weather Service lightning safety page shows that most lightning casualties occur before a thunderstorm is fully overhead, or before it fully departs the area, when people might not realize their vulnerability to lightning and don’t seek shelter soon enough or leave shelter too soon.

Animation depicting the threat of lightning casualties as a function of a hypothetical storm moving into the area.

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Hail in Portland OR

Here’s a text received late on 8 May from a kid: “Hail today in Portland”. The animation above shows GOES-17 Visible (0.64 µm) imagery between 2201 UTC on 8 May and 0311 UTC on 9 May. The follow-up text answering the obvious question (What time?) was “Around 5 PM” —... Read More

GOES-17 Visible Band 2 (0.64 µm) imagery, 2201 UTC 8 May 2022 – 0311 UTC 9 May 2022 (Click to enlarge)

Here’s a text received late on 8 May from a kid: “Hail today in Portland”. The animation above shows GOES-17 Visible (0.64 µm) imagery between 2201 UTC on 8 May and 0311 UTC on 9 May. The follow-up text answering the obvious question (What time?) was “Around 5 PM” — that is, around 0000 UTC on 9 May. Infrared imagery (Band 13, 10.3 µm) from GOES-17 over the same time period — 2201 – 0311 UTC — is shown below. This loop uses a default enhancement from AWIPS (which enhancement has as its coolest temperature -109oC, perhaps too cold for this airmass; click here to see an animation with a coolest temperature of -90oC; variability in the cold cloud tops is much easier to visualize in that modified color enhancement).

GOES-17 Infrared Band 13 (10.3 µm) imagery, 2201 UTC 8 May 2022 – 0311 UTC 9 May 2022 (Click to enlarge)

The slower animation below, between 0000 UTC and 0100 UTC, highlights the cold cloud tops (west of Portand) of the system that might have produced hail. The eye is drawn to the developing cold cloud tops with the tweaked (non-default) enhancement. (By this time, having examined the imagery, I wonder about the report of the hail occurring around 5 PM; This event was also mentioned on the NWS Portland Facebook page).

GOES-17 Visible Imagery (left), Infrared (center, with default enhancement) and infrared (right, with a smaller range to the enhancement), 0000-0100 UTC on 9 May 2022 (click to enlarge)

LightningCast Probability is a product in the NOAA/CIMSS ProbSevere portfolio that predicts the likelihood of a GLM Flash Event based on a single time of the GOES-17 bands that are used in the Day Cloud Phase Distinction RGB: Bands 2 (0.64 µm), 5 (1.61 µm) and 13 (10.3 µm). The animation of that field is shown below. Contours denote probabilities of 10% (dark blue), 25% (cyan), 50% (green) and 75% (magenta). One lightning flash is shown at the of the animation; note however how the probability contours center on the strongest developing convective cell early in its lifecyle — even though it never produced lightning as detected by the GOES-17 GLM.

LightningCast Probability, 2335 UTC on 8 May 2022 – 0100 UTC on 9 May 2022 (click to enlarge)

NOAA-20 overflew the Pacific Northwest in the afternoon, with two passes over Oregon, as shown in the toggle below that also shows gridded 850-500 mb NUCAPS Lapse Rates at 1933 and 2113 UTC on 8 May. Even though the westernmost NOAA-20 has truncated data, very steep lapse rates — near 8o C/km — are evident.

Gridded 850-500 mb Lapse Rates, 1933 and 2115 UTC on 8 May 2022 (click to enlarge)

500-mb temperatures are shown below, with Portland deep within the cold air (500-mb temperatures are at/below -30o C!). The gridded fields look smooth despite the abundance of yellow and red points in the NUCAPS fields, designating regions where the infrared retrieval did not converge (yellow) or where the infrared and microwave retrievals both failed! This example shows that profiles that do not converge because of low-level clouds/moisture/rain may nevertheless produce useful upper-air information. The 2113 UTC 500-mb temperature field here, shows a red profile in the Willamette Valley in the northernmost row of profiles, and a green profile in the same row just west of the Oregon Coast. The toggle of profiles at those two points is shown below; both have useful information around 500 mb (and above) even though near-surface values in the red profile are of dubious value. Note the steep lower-tropospheric lapse rates in the sounding that is just offshore!

Gridded 500-mb Temperature derived from NUCAPS profiles, 1933 UTC and 2115 UTC on 8 May 2022 (click to enlarge)
NUCAPS profiles at circled (in black) locations, 2138 UTC on 8 May 2022 (click to enlarge)

NUCAPS imagery was created with the NOAA/TOWR-S AWIPS Cloud instance. Thank you!

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