Severe Thunderstorms in southwest Missouri

July 19th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm), with hourly surface plots plotted in cyan/yellow and SPC storm reports plotted in red [click to play MP4 animation | Animated GIF]

1-minute Mesoscale Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the intensification of thunderstorms over far southwestern Missouri during the early evening hours on 19 July 2018. Surface outflow from these storms produced damaging winds (SPC storm reports), including a gust to 55 knots or 63 mph at Branson (plot | list) at 0025 UTC. Strong winds capsized a boat on Table Rock Lake — located about midway between Branson West Airport KFWB and Branson Airport KBBG (map) — resulting in 17 fatalities. The 0025 UTC image showed a new cell which had recently developed just northeast of Branson; its overshooting tops began rapidly penetrating the anvil debris of the earlier storms at 0018 UTC.

The corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below) revealed cloud-top infrared brightness temperatures cooling to the -75 to -79ºC range (shades of light gray to white) with both thunderstorms in southwest Missouri.

GOES-16 "Clean" Infrared Window (10.3 µm), with hourly surface plots plotted in cyan/yellow and SPC storm reports plotted in dark blue [click to play MP4 animation | Animated GIF]

GOES-16 “Clean” Infrared Window (10.3 µm), with hourly surface plots plotted in cyan/yellow and SPC storm reports plotted in purple [click to play MP4 animation | Animated GIF]

Tornado outbreak in Iowa

July 19th, 2018 |

GOES-16 Upper-level Water Vapor (6.2 µm, top left), Mid-level Water Vapor (6.9 µm, top right), Low-level Water Vapor (7.3 µm, bottom left) and

GOES-16 Upper-level Water Vapor (6.2 µm, top left), Mid-level Water Vapor (6.9 µm, top right), Low-level Water Vapor (7.3 µm, bottom left) and “Red” Visible (0.64 µm, bottom right) images [click to play MP4 animation]

GOES-16 (GOES-East) Upper-level Water Vapor (6.2 µm), Mid-level Water Vapor (6.9 µm), Low-level Water Vapor (7.3 µm) and “Red” Visible (0.64 µm) images (above) revealed the well-defined signature of a mid-tropospheric lobe of vorticity moving from southeastern South Dakota across Iowa during the day on 19 July 2018 — this feature provided synoptic-scale forcing for ascent which aided in the development of severe thunderstorms in central and eastern Iowa. A number of tornadoes were reported, along with some large hail and damaging winds (SPC storm reports).

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with SPC storm reports plotted in red [click to play MP4 animation]

A closer look using 1-minute Mesoscale Sector GOES-16 “Red” Visible (0.64 µm) images (above) showed the line of thunderstorms as they developed in advance of an approaching cold/occluded front (surface analyses). Two larger storms were dominant, which produced tornadoes causing significant damage and injuries in Pella KPEA and Marshalltown KMIW — above-anvil plumes were evident with both of these supercells. In addition, early in the animation a few orphan anvils could be seen along the southern end of the line (southeast and east of Des Moines KDSM).

The corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below) showed cloud-top infrared brightness temperatures of -65ºC to -70ºC with the larger Pella storm, and around -55ºC with the smaller Marshalltown storm to the north.

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with SPC storm reports plotted in red [click to play MP4 animation]

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) image, with ProbSevere contour and parameters [click to enlarge]

The NOAA/CIMSS ProbSevere model (viewed using RealEarth) had a ProbTor value of 74% at 2055 UTC for the Pella storm (above) and 83% at 2130 UTC for the Marshalltown storm (below). GOES-derived Cloud-top glaciation rate (from infrared imagery) is one of the predictors used in the model.

GOES-16 Infrared image, with ProbSevere parameters [click to enlarge]

GOES-16 “Clean” Infrared Window (10.3 µm) image, with ProbSevere contour and parameters [click to enlarge]

A ProbSevere time series for object 621481, above, is shown below; it indicated that ProbTor ramped up quickly and then down quickly, bracketing the time of the tornado in Marshalltown.

NOAA/CIMSS ProbHail (Green), ProbWind (Blue) and ProbTor (Red) for the cell that produced the Marshalltown IA tornado. (Click to enlarge)

A toggle between 375-meter resolution Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images at 1946 UTC (below) provided a look at the early stage of development of tornado-producing convection.

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images, with plots of SPC tornado reports within +/- 30 minutes of the images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images, with plots of SPC tornado reports within +/- 30 minutes of the images [click to enlarge]

Additional satellite imagery and analysis of this event can be found on the Satellite Liaison Blog.


Comparisons of GOES-15, GOES-16 and GOES-17

July 17th, 2018 |
Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

* GOES-17 imagery shown here are preliminary and non-operational *

A 3-panel comparison of Visible images from GOES-15 (GOES-West), GOES-17 and GOES-16 (GOES-East) shown above highlights the dissipation of fog in the Strait of Juan de Fuca during the morning hours on 17 July 2018. The three sets of images are displayed in the native projection of each satellite (with no re-mapping) — GOES-17 was at its post-launch checkout location of 89.5ºW longitude.  Images from GOES-16/17 were at 5-minute intervals, while images from GOES-15 were every 5-15 minutes depending on the operational scan schedule of that GOES-West satellite.

A similar 3-satellite comparison shown below focuses on the development of showers and thunderstorms across western Montana, between Missoula KMSO and Butte KBTM. The improved spatial resolution (0.5 km at sub-satellite point for GOES-16/17, vs 1.0 km for GOES-15) and more frequent images allowed small-scale features of the storms to be more easily identified and followed.

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

One final comparison, shown below, depicts thunderstorms over western Colorado — outflow boundaries south of these storms produced strong surface winds in the Grand Junction area (SPC storm reports).

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) — SPC storm reports of wind are plotted in red [click to play animation | MP4]


Severe thunderstorms in Wyoming and South Dakota

June 29th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with SPC storm reports plotted in red [click to play MP4 animation]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the development of large clusters of thunderstorms that moved from northeastern Wyoming into South Dakota during the afternoon and evening hours on 29 June 2018. These storms produced a variety of severe weather (SPC storm reports | NWS Rapid City), including tornadoes, hail of 4.50 inches in diameter and damaging wind gusts of 90 mph.

The corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below) indicated that the coldest cloud-top infrared brightness temperatures associated with the strongest overshooting tops were generally around -70ºC (black enhancement).

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with SPC storm reports plotted in cyan [click to play MP4 animation]

GOES-16 Mid-level Water Vapor (6.9 µm) images (below) revealed a shortwave trough which was moving eastward across the northern Rocky Mountains — the approach of this mid-tropospheric trough was bringing enhanced forcing for ascent to aid in the development of thunderstorms.

GOES-16 Mid-level Water Vapor (6.9 µm) images [click to play MP4 animation]

GOES-16 Mid-level Water Vapor (6.9 µm) images [click to play MP4 animation]

===== 30 June Update =====

A comparison of before/after Terra MODIS True Color Red-Green-Blue (RGB) images viewed using RealEarth (below) revealed a pair of crop/vegetation damage swaths — the first (oriented northwest to southeast) caused by storms early on 27 June, and the second (oriented approximately west to east) caused by the 29 June storms shown on the GOES-16 imagery above. One SPC storm report listed hail of 2.00 inches in diameter with winds gusting to 69 mph near Mission Ridge SD — wind-driven hail of that size can easily inflict significant damage to structures and vegetation.

Terra MODIS True-Color images on 26 June, 27 June and 30 June [click to enlarge]

Terra MODIS True Color RGB images on 26 June, 27 June and 30 June [click to enlarge]

===== 02 July Update =====

Aqua MODIS True Color RGB image [click to enlarge]

Aqua MODIS True Color RGB image [click to enlarge]

An Aqua MODIS True Color RGB image on 02 July (above) provided a cloud-free view of the segmented west-to-east 29 June hail/wind damage path across western/central South Dakota — NWS Aberdeen noted that the storm producing this damage traveled more than 420 miles. In addition, the hazy signature of smoke being transported northeastward (from wildfires in Colorado) was apparent at the bottom center of the image. These hail/wind damage swaths (as well as the wildfire smoke aloft) were also evident in GOES-16 Natural Color RGB imagery.

Looking at the corresponding Aqua MODIS Visible (0.65 µm) image, Normalized Difference Vegetation Index (NDVI) product and Land Surface Temperature (LST) product (below), the hail/wind damage swaths were characterized by NDVI values in the 0.2-0.4 range (compared to adjacent healthy vegetation values of 0.7-0.8) and LST values  warmer than 100-110ºF (adjacent healthy vegetation LST values were generally in the 80s F). The lowest NDVI values were observed in parts of Sully and Hughes Counties, within the northwest-to-southeast 27 June damage path — there were reports of extensive crop devastation and wildlife casualties in that area (media story).

Aqua MODIS Visible (0.65 µm) image and Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) products [click to enlarge]

Aqua MODIS Visible (0.65 µm) image, Normalized Difference Vegetation Index (NDVI) product and Land Surface Temperature (LST) product [click to enlarge]