Grass fire in the Oklahoma Panhandle

April 5th, 2022 |

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), Fire Power (bottom left) and Fire Temperature (bottom right) [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images along with 5-minute Fire Power and Fire Temperature products (above) displayed the smoke plume and thermal signature of a grass fire that rapidly intensified and spread across parts of western Beaver County (located in the Oklahoma Panhandle) on 05 April 2022. The Fire Temperature and Fire Power derived products are components of the GOES Fire Detection and Characterization Algorithm FDCA. Thermal signatures became evident around 1700 UTC or Noon CDT; within about 2 hours this fire was already burning very hot, with 3.9 µm Shortwave Infrared brightness temperatures reaching 138.71ºC — the saturation temperature of ABI Band 7 detectors — around 1915 UTC.

A strong cold front was moving southward across the High Plains during the day (surface analyses) — and arrived at the grass fire’s location just after 2000 UTC (causing a brief flare-up of the fire thermal signatures, and a final pyrocumulus pulse). The surge of colder air behind the cold front showed up as darker shades of green in the 3.9 µm images. Th initial east-southeastward expansion of the hot thermal 3.9 µm signature quickly transitioned to a south-southwestward expansion in the wake of the frontal passage.

1-minute GOES-16 True Color RGB images created using Geo2Grid (below) showed the initial eastward spread of the smoke plume prior to the arrival of the cold front — followed by a pronounced south-southwestward transport of smoke from the fire source region after the cold front moved across the area.

GOES-16 True Color RGB images [click to play animated GIF | MP4]

The polar-orbiting Suomi-NPP satellite passed over that region around 1923 UTC — a toggle between True Color and False Color RGB images is shown below. The data to produce these images were downloaded and processed by the SSEC/CIMSS Direct Broadcast ground station (and are available for display in AWIPS via an LDM feed).

Suomi-NPP VIIRS True Color and False Color RGB images at 1923 UTC [click to enlarge]

Incidentally, Beaver County in Oklahoma experienced another fast-moving grass fire in March 2020.

Severe weather in South Carolina

April 5th, 2022 |
ProbSevere (version 2) over South Carolina, 1902-2012 UTC on 5 April 2022 (click to enlarge)

SPC Storm Reports from 5 April 2022 note a Tornado hit Allendale SC shortly before 2000 UTC. The animation above shows the ProbSevere (version 2 — available online here) display prior to and just after the tornado. NOAA/CIMSS ProbSevere identifies and tracks the radar feature associated with this tornadic storm. ProbSevere is designed to give forecasters more confidence in warning issuance. ProbSevere in this case highlights the radar object associated with model fields and satellite/radar observations that are most suggestive of a storm supporting tornadogenesis — note that ProbSevere values in adjacent cells are smaller. A meteorogram of this radar object, shown below (and available here), shows the ProbSevere components, and also ProbHail/ProbWind/ProbTor/Probsevere values, for both versions 2 and 3. ProbSevere values increased at around 1930 UTC. ProbSevere v3 values generally are smaller than ProbSevere v2 values; ProbSevere v3 will be demonstrated this year at the Hazardous Weather Testbed (HWT) this year. (Click here to view the Charleston, SC (KCLX) radar at 1958 UTC; a pronounced hook is apparent)

ProbSevere readout meteogram, Object Number 653760, 5 April 2022 (Click to enlarge). For the ProbSevere readout (top row), ProbTor values are in red, ProbHail values are in green, ProbWind values are in blue. (Click to enlarge)

This tornadic cell stood out in the visible imagery. GOES-16 Mesoscale Sector #2 on 5 April included portions of South Carolina. The mp4 animation below, from the CSPP Geosphere site, (this direct link to the animation will be valid for a bit less than a week) shows the tornadic cell erupting at around 1930 UTC near the Georgia/South Carolina border.

GOES-16 Visible Imagery (Band 2, at 0.64 µm) from Mesoscale Sector 2, 1900-2005 UTC 2022

Observations — satellite and radar — both showed the obvious storm. How did short-range guidance perform? A Polar Hyperspectral modeling system — also to be demonstrated at the Hazardous Weather Testbed — produces hourly 18-hour forecasts with initial fields influenced by Sounder Data from the Polar Orbiting satellites Suomi-NPP, NOAA-20, Metop-B and Metop-C. Infrared sounder (CrIS on Suomi/NPP and IASI on Metop) and Microwave sounder (ATMS on Suomi/NPP, AMSU/MHS on Metop) data can produce a more accurate initialization of the moisture distribution in atmosphere. The forecast initialized at 1200 UTC for Lifted Index and Significant Tornado Parameter, valid at 18, 19 and 20 UTC — that is, 6-h, 7-h and 8-h forecasts, below, shows increasing instability before the tornado in Allendale.

Lifted Index (left) and Significant Tornado Parameter (right) at 1800, 1900 and 2000 UTC on 5 April 2022 (Click to enlarge). Forecast initialized at 1200 UTC on 5 April 2022

The model runs initialized at 1700, 1800 and 1900 UTC, showing fields from initialization through 0000 UTC on 6 April 2022, are shown below. Note that the area with a Significant Tornado Parameter signal is mostly confined to southeastern South Carolina — that is, near the coast. Storm reports show that severe weather was mostly near the coast as well.

Lifted Index (left) and Significant Tornado Parameter (right) hourly from at 1700 UTC on 5 April 2022 through 0000 UTC on 6 April 2022 (Click to enlarge). Forecast initialized at 1700 UTC on 5 April 2022
Lifted Index (left) and Significant Tornado Parameter (right) hourly from at 1800 UTC on 5 April 2022 through 0000 UTC on 6 April 2022 (Click to enlarge). Forecast initialized at 1800 UTC on 5 April 2022
Lifted Index (left) and Significant Tornado Parameter (right) hourly from at 1900 UTC on 5 April 2022 through 0000 UTC on 6 April 2022 (Click to enlarge). Forecast initialized at 1900 UTC on 5 April 2022

These fields are also available in AWIPS via an LDM feed (in preparation for HWT). The 3 images below show changes in the 2000 UTC forecast (from the model initialized at 1400, 1600 and 1700 UTC). The trend towards higher Significant Tornado Parameter over southeastern South Carolina is obvious. Note that Allendale’s location is shown.

Significant Tornado Parameter valid at 2000 UTC on 5 April 2022 from forecasts initialized at 1400, 1600 and 1700 UTC (Click to enlarge)

Added: the GLM on GOES-16 saw a dramatic increase in Flash Extent Density with the tornadic storm starting around 1925 UTC on 5 April. (Click here to see a slower animation from 1920 – 1930 UTC)

GOES-16 GLM Flash Extent Density, 1900-2029 UTC on 5 April 2022 (Click to enlarge)

Turbulence over the Pacific Ocean northeast of Hawai’i

April 5th, 2022 |
Probabilities of Moderate-or-Greater (MOG) Turbulence over the Pacific, 0550-1030 UTC on 5 April 2022 (Click to enlarge)

Probability of Moderate or Greater (MOG) Turbulence is a Machine-Learning product that uses satellite imagery (Band 13 — the clean window infrared channel at 10.3 µm — over the GOES-West domain; GOES-16 Probabilities use both Band 13 and the upper-level water vapor imagery — Band 8 at 6.19 µm; training on this product is available here) and GFS estimates of tropospheric stability. The animation above (from this website) shows an axis of maximum probabilities to the northeast of Hawai’i. Two pilot reports of turbulence are plotted in that axis, one near 0910 UTC, one near 1000 UTC.

The upper-level water vapor imagery associated with this feature is shown below. The GOES-17 upper-level water vapor imagery displayed below is showing the effects of the poor functionality of the Loop Heat Pipe (you can investigate more on this topic here). In this animation, that effect is manifest by flickering in the image (that is especially noteable around 11 UTC). The overnight imagery should degrade further in the next few days before recovering later in May.

GOES-17 Band 8 (Upper-level water vapor, 6.19 µm) 0641-1316 UTC on 5 April 2022 (Click to enlarge)

GOES-17 MOG Turbulence Probability is available in AWIPS, as shown below. The product is produced from the Full Disk Imagery, that is, with a 10-minute cadence.

GOES_17 Band 8 Upper Level Water Vapor Infrared imagery, and GOES-17 MOG Probability 0900 UTC on 5 April 2022 (Click to enlarge)

The CIMSS Weighting Function website can gauge from what level the information sensed in the upper-level water imagery emerges. The image below, using 0000 UTC GFS data, suggests the information is originating around 300 mb.

CIMSS Weighting Function website output, 0000 UTC on 5 April 2022 (Click to enlarge)