Severe weather in the Northeastern US

May 15th, 2018 |

GOES-16

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

Severe thunderstorms developed along and ahead of a cold front that was moving across the Northeastern US on 15 May 2018. 1-minute Mesoscale Domain Sector GOES-16 “Red” Visible (0.64 µm) images (above) showed the progression of these storms — and SPC storm reports (plotted in red, and parallax-corrected to align with the corresponding cloud-top feature) included an EF2 tornado at 2029 UTC near Kent, New York and a macroburst producing winds of 100-110 mph at 2044 UTC near Brookfield, Connecticut.

The corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below) showed the evolution of cold overshooting tops, as well as the development of a few “enhanced-v” signatures with a pronounced warm wake immediately downwind of the cold overshooting top.

GOES-16

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

A toggle between 1-km resolution POES (NOAA-19) AVHRR Near-Infrared “Vegetation” (0.86 µm) and “Dirty” Infrared Window (12.0 µm) images (below) provided a more detailed view of the storm at 2004 UTC. SPC storm reports within +/- 30 minutes of the image are plotted on the 12.0 µm image.The coldest cloud-top infrared brightness temperature was -82ºC, associated with an overshooting top in southeastern New York.

POES (NOAA-19) Visible (0.86 µm) and Inrared (12.0 µm) images, with plots of SPC storm reports [click to enlarge]

POES (NOAA-19) Near-Infrared “Vegetation” (0.86 µm) and “Dirty” Infrared Window (12.0 µm) images, with plots of SPC storm reports [click to enlarge]

Fires in Saskatchewan

May 15th, 2018 |

GOES-16 ABI Band 1 (“Blue Visible”, 0.47 µm, top), Band 2 (“Red Visible”, 0.64 µm, middle) and Band 7 (“Shortwave Infrared”, 3.9 µm, bottom) from 1345 to 2230 UTC on 15 May 2018 (Click to animate);  Note that the yellow enhancement in the shortwave infrared starts at 305 K.

Fires that developed over the plains of Saskatchewan, near Meadow Lake in west-central Saskatchewan, and near Prince Albert in central Saskatchewan, showed up well in Visible and Infrared imagery, shown above.  A wind shift that occurred as the fires burned changed the direction of the smoke plume.  Prince Albert had visibilities that dropped to 3 statute miles.  Meadow Lake had visibilities down to 4 statute miles.

True-Color imagery (Source: (Link), imagery provided by Paul Ford, ECC Canada), also shows the distinct smoke plumes from the fires.

True-Color imagery over Saskatchewan, 1730-2000 UTC

The Dual-Pol S-band radar at Radisson captured the plume north of Prince Albert at 1900 UTC (See below; click here for the satellite imagery at that time).  Very small Cross-Correlation coefficients are apparent in the smoke plume. The radar at 2010 UTC (link) suggests 3 separate fires, which agrees with the satellite imagery. (Click here for 2015 UTC Satellite Imagery).

Cross-Correlation Scan from the dual pol, S-band at Radisson, Saskatchewan, 1900 UTC on 15 May 2018 (Click to enlarge)

Many Thanks to Paul Ford, ECC Canada, for the radar imagery, and for alerting us to this event. Saskatchewan fires can be tracked at this website. Most of Saskatchewan is currently under a fire ban.


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AWIPS imagery of this fire were collected. Click here to see the towns of the region. Full-disk imagery is available from GOES-16 at 15-minute increments. The 3.9 µm imagery is shown from 1200 to 2345 UTC, followed by the Fire RGB Imagery. The Fire RGB image combines the 3.9 µm (Red), 2.2 µm (Green) and 1.6 µm (Blue) imagery. The wavelength of the radiation emitted by the fire decreases as the temperature of the fire increases; a relatively cool fire will emit mostly 3.9 µm energy and will be red in the RGB. A very hot fire will emit all three wavelengths and will appear whiter in the RGB.

GOES-16 ABI Band 7 (“Shortwave Infrared”, 3.9 µm) from 1200 to 2345 UTC on 15 May 2018 (Click to enlarge)

GOES-16 ABI Fire RGB, combining 3.9 µm, 2.2 µm and 1.6 µm imagery, from 1200 to 2345 UTC on 15 May 2018 (Click to enlarge)

The imagery below is zoomed in on the region of the three fires.  (Map).  The 3.9 µm is shown first, then the Fire RGB.

GOES-16 ABI Band 7 (“Shortwave Infrared”, 3.9 µm) from 1200 to 2345 UTC on 15 May 2018 (Click to enlarge)

GOES-16 ABI Fire RGB, combining 3.9 µm, 2.2 µm and 1.6 µm imagery, from 1200 to 2345 UTC on 15 May 2018 (Click to enlarge)

 

The RGB — like many — gives an excellent qualitative estimate of the fire.  Quantitative estimates are available that more define the fire more comprehensively. The 1845 UTC Fire RGB suggests a very hot fire (the 3.9 µm imagery at 1845 UTC suggests the same thing). What do the Baseline fire products show? The Fire Temperature, Fire Power, and Fire Area products for 1845 UTC are shown below.  (Animations are here:  Fire Temperature, Fire Power, Fire Area)   Hotter fire pixels are apparent at 1745 and 2015 UTC.    Click for toggles of Band 7 (3.9 µm), Fire RGB and Baseline Fire Temperature at 1745 UTC, 1845 UTC, and 2015 UTC.  These products might facilitate resource allocation in a way that single channels or RGB combinations cannot.

GOES-16 Baseline Fire Temperature Product 1845 UTC on 15 May 2018 (Click to enlarge)

GOES-16 Fire Power Baseline Product, 1845 UTC on 15 May 2018 (Click to enlarge)

GOES-16 ABI Fire Area Baseline Product at 1845 UTC on 15 May 2018 (Click to enlarge)