Severe thunderstorms in Indiana and Ohio

May 27th, 2019 |

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

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

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) revealed supercell thunderstorms that developed within the warm sector of a midlatitude cyclone approaching from the Upper Midwest (surface analyses) — these thunderstorms produced a variety of severe weather (SPC Storm Reports | NWS Northern Indiana) across Indiana late in the day on 27 May 2019.

Many of these storms exhibited well-defined overshooting tops; the largest hail was 4.0 inches in diameter at 0000 UTC. A comparison of SPC Storm Reports at the time of this large hail (and a nearby wind gust to 72 mph) — plotting the reports at the actual ground location vs a “parallax-corrected” location which shifted them northwestward — showed that the severe report locations closely corresponded to the overshooting top (below).

GOES-16 “Red” Visible (0.64 µm) images, with SPC Storm Reports plotted in red [click to enlarge]

GOES-16 “Red” Visible (0.64 µm) image at 0000 UTC, with SPC Storm Reports plotted in red [click to enlarge]

The corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images (below) showed that many of the overshooting tops had infrared brightness temperatures in the -70 to -75ºC range.

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

As the thunderstorms moved eastward across Ohio, they continued to produce all modes of severe weather (including EF-3 and EF-4 tornadoes in the Dayton area beginning around 0258 UTC). Additional information on these storms is available from the Hazardous Weather Testbed.

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

A Terra MODIS Infrared Window (11.0 µm) image at 0243 UTC with plots of SPC Storm Reports within +/- 45 minutes of the image time (below) showed cloud-top infrared brightness temperatures as cold as -73ºC.

Terra MODIS Infrared Window (11.0 µm) image with plots of SPC Storm Reports within +/- 45 minutes of the image time [click to enlarge]

Terra MODIS Infrared Window (11.0 µm) image with plots of SPC Storm Reports within +/- 45 minutes of the image time [click to enlarge]

Severe thunderstorms in Oklahoma

May 25th, 2019 |

GOES-16

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (above) showed squall line thunderstorms which produced tornadoes, large hail and damaging winds (SPC Storm Reports) across Oklahoma on the evening of 25 May 2019. Of significance was the EF-3 tornado that affected El Reno, Oklahoma which was responsible for 2 fatalities (NWS Norman).

The GOES-16 Infrared imagery revealed evidence of pulsing updrafts (clusters of colder, brighter white pixels) to the northwest of El Reno (KRQO) — between Watonga (KJWG) and Weatherford (KOJA) — that began at 0248 UTC. 1-minute Infrared brightness temperatures associated with the bowing segment then fluctuated between -73.3ºC and -76.3ºC during the subsequent 40 minutes leading up to the El Reno tornado at 0328 UTC (below). Correcting for parallax, this would have moved those pulsing updrafts southeastward, closer to KRQO.

1-minute Infrared brightness temperatures associated with the bowing segment that produced the El Reno tornado [click to enlarge]

1-minute Infrared brightness temperatures associated with the bowing segment that produced the El Reno tornado [click to enlarge]

One way of illustrating the magnitude of the GOES-16 parallax shift is to compare SPC Storm Reports at the time of the El Reno tornado — plotting the reports at the actual ground location vs a “parallax-corrected” location which shifts them northwestward to more closely correspond to the 13-km mean height of the storm-top Infrared features (below). Note that the parallax-corrected El Reno tornado report location is nearly coincident with that of a colder (lighter shade of white) overshooting top.

GOES-16 "Clean" Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to enlarge]

GOES-16 “Clean” Infrared Window (10.35 µm) images, with surface and parallax-corrected SPC Storm Reports plotted in cyan [click to enlarge]

About an hour after the El Reno tornado, a Terra MODIS Infrared Window (11.0 µm) image (below) displayed cloud-top infrared brightness temperatures as cold as -73ºC as the thunderstorms moved eastward and spread severe weather into the Tulsa area.

Terra MODIS Infrared Window (11.0 µm) image, with plots of SPC Storm Reports with +/- 45 minutes of the image time [click to enlarge]

Terra MODIS Infrared Window (11.0 µm) image, with plots of SPC Storm Reports with +/- 45 minutes of the image time [click to enlarge]

Severe thunderstorms across Oklahoma, Kansas and Missouri

May 22nd, 2019 |

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

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

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the development of supercell thunderstorms that produced tornadoes, large hail and damaging winds (SPC Storm Reports) across parts of Oklahoma, Kansas and Missouri on 22 May 2019.

GOES-16 “Clean” Infrared Window (10.35 µm) images (below) showed the storms as they persisted into the nighttime hours — including storms that produced EF3-rated tornadoes that affected Golden City, Missouri around 0211 UTC (which was responsible for 3 fatalities) and Jefferson City, Missouri around 0440 UTC.

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

A closer look at 1-minute GOES-16 Infrared images for the storm producing the EF-3 tornado that affected Golden City, Missouri  is shown below. A pulsing updraft with cold (brighter white) infrared brightness temperature overshooting tops could be seen with the parent supercell as it crossed the Oklahoma/Kansas border around 0000 UTC, moved across extreme southeastern Kansas, then moved into southwestern Missouri around 0100 UTC. The NWS Springfield damage survey listed the start time of the Garden City tornado at 0151 UTC.

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

About 20 minutes prior to the Jefferson City tornado, a Terra MODIS Infrared Window (11.0 µm) image (below) displayed a well-defined Enhanced-V storm top signature.

Terra MODIS Infrared Window (11.0 µm) image. with plot of SPC storm reports [click to enlarge]

Terra MODIS Infrared Window (11.0 µm) image, with plot of SPC storm reports [click to enlarge]

A closer look at 1-minute GOES-16 Infrared images for the storm producing the EF-3 tornado that affected Jefferson City (KJEF) is shown below — of note are the 2 pre-tornado updraft pulses west/southwest of KJEF at 0346 UTC and 0359 UTC, when cloud-top infrared brightness temperatures briefly cooled to -81ºC and -82ºC, respectively (violet pixels). The NWS St. Louis storm survey indicated that the tornado which eventually moved through Jefferson City began southwest of the city at 0420 UTC.

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

A few hours later, a sequence of 3 VIIRS Infrared Window (11.45 µm) images (below) from Suomi NPP and NOAA-20 showed the line of supercell thunderstorms between 0704 and 0844 UTC.

VIIIRS Infrared Window (11.45 µm) images from Suomi NPP (0704 and 0844 UTC) and NOAA-20 (0754 UTC) [click to enlarge]

VIIRS Infrared Window (11.45 µm) images from Suomi NPP (0704 and 0844 UTC) and NOAA-20 (0754 UTC) [click to enlarge]

A closer view of the Suomi NPP VIIRS Infrared Window (11.45 µm) image at 0704 UTC (below) revealed another well defined Enhanced-V signature in far northeastern Oklahoma.

Suomi NPP VIIRS Infrared Window (11.45 µm) image at 0704 UTC [click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) image at 0704 UTC [click to enlarge]

The Suomi NPP VIIRS Infrared Window (11.45 µm) image at 0844 UTC (below) depicted an example of a warm “moat” surrounding a cold overshooting top having a minimum infrared brightness temperature of -81ºC (violet enhancement) east of Patoka, Illinois.

Suomi NPP VIIRS Infrared Window (11.45 µm) image at 0844 UTC [click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) image at 0844 UTC [click to enlarge]

Transport of Canadian wildfire smoke across the Northeast US

May 22nd, 2019 |

GOES-16 CIMSS Natural Color images, with an overlay of the Smoke Detection Product ;click to play animation | MP4]

GOES-16 CIMSS Natural Color RGB images, with an overlay of the Smoke Detection Product [click to play animation | MP4]

GOES-16 (GOES-East) CIMSS Natural Color Red-Green-Blue (RGB) images with an overlay of the Smoke Detection Product (above) revealed curved filaments of wildfire smoke moving southeastward across the Northeast US and the adjacent offshore waters of the Atlantic Ocean on 22 May 2019. The smoke filaments were classified as Medium/High confidence by the algorithm — additional information on GOES-R Aerosol Detection Products in AWIPS is available here and here.

During the preceding overnight hours, with ample illumination from the Moon (in the Waning Gibbous phase, at 92% of Full) smoke filaments were evident over the Atlantic Ocean on Suomi NPP VIIRS Day/Night Band (0.7 µm) imagery at 0722 UTC or 3:22 AM Eastern Time (below). Note that the smoke did not exhibit a signature in the corresponding VIIRS Infrared Window (11.45 µm) image, since thin smoke layers are effectively transparent to infrared radiation.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0722 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0722 UTC [click to enlarge]

Daily composites of Suomi NPP VIIRS True Color RGB images with VIIRS Fire Detections viewed using RealEarth (below) showed that thick smoke from wildfires in northern Alberta — primarily the Chuckegg Creek Fire that forced evacuations in the town of High Level — was initially lofted above the meteorological clouds over the Northwest Territories and Nunavut on 19 May and 20 May, before eventually moving southeastward across central/eastern Canada.

Daily composites of Suomi NPP VIIRS True Color RGB images with Fire Detections, 18-22 May [click to play animation]

Daily composites of Suomi NPP VIIRS True Color RGB images with Fire Detections, 18-22 May [click to play animation]

HYSPLIT model 72-hour back trajectories from 3 points corresponding to the smoke filaments seen in the GOES-16 imagery off the Northeast US coast (below) confirmed an initial anticyclonic transport from the region of the Alberta wildfires, with a subsequent southeastward transport across Canada and eventually the Northeast US.

HYSPLIT model 72-hour back trajectories from 3 points off the Northeast US coast [click to enlarge]

HYSPLIT model 72-hour back trajectories from 3 points off the Northeast US coast

6-hourly GFS 500 hPa analyses (source) shown below help to explain the smoke transport as seen in both the VIIRS imagery and the HYSPLIT trajectories — a ridge of high pressure was present over western Canada early in the period, with a transition to a deepening longwave trough over eastern Canada with a shortwave trough digging across Quebec and the Maritimes on 21-22 May. Strong descent of the trajectories occurred during the final 12 hours of transport, on the back side of the digging shortwave trough.

6-hourly GFS 500 hPa analyses [click to enlarge]

6-hourly GFS 500 hPa analyses, from 12 UTC on 18 May to 12 UTC on 22 May [click to enlarge]