Paper mill fire in New Jersey

January 30th, 2019 |

GOES-16 Near-Infrared

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm, top), Near-Infrared “Cloud Particle Size” (2.24 µm, center) and Shortwave Infrared (3.9 µm, bottom) images, with hourly plots of surface observations [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (above) displayed thermal signatures from a large fire at the Marcal Paper Mill in Elmwood Park, New Jersey during the evening hours of 30 January 2019. The fire reportedly began around 2215 UTC or 5:15 PM local time — and during the subsequent hours, strong winds with very cold temperatures (falling to the single digits above zero F) in the wake of a cold frontal passage hampered the firefighting efforts. Note on the plots of surface observations that smoke (K) was reported immediately downwind of the fire at Teterboro Airport (station identifier KTEB) from 02 to 05 UTC.

The nighttime thermal signatures seen on the near-infrared 1.61 µm and 2.24 µm images (brighter white pixels) result from the fact that those two ABI spectral bands are located close to the peak emitted radiance of very hot features such as volcanic eruptions or large fires (below).

Plots of Spectral Response Functions for ABI Bands 5, 6 and 7 [click to enlarge]

Plots of Spectral Response Functions for ABI Bands 5 (1.61 µm), 6 (2.24 µm) and 7 (3.9 µm) [click to enlarge]

The thermal signature of the fire became less distinct in GOES-16 imagery after about 06 UTC, but was still well-defined in higher-resolution VIIRS Shortwave Infrared (3.74 µm) imagery (below) from NOAA-20 (overpass data acquired at 0614 and 0754 UTC) and Suomi NPP (overpass data acquired at 0704 UTC).

VIIRS Shortwave Infrared (3.74 µm) images from NOAA-20 (at 0614 and 0754 UTC) and Suomi NPP (at 0704 UTC) [click to enlarge]

VIIRS Shortwave Infrared (3.74 µm) images from NOAA-20 (at 0614 and 0754 UTC) and Suomi NPP (at 0704 UTC) [click to enlarge]

Cold weather outbreak across the Upper Midwest and Great Lakes

January 30th, 2019 |

GOES-16 Air Mass RGB images, 28-30 January [click to play MP4 animation]

GOES-16 Air Mass RGB images, 28-30 January [click to play MP4 animation]

A highly-amplified upper air and jet stream pattern allowed a lobe of the polar vortex to migrate southward across southern Canada and the north-central US — leading to an outbreak of arctic air throughout the Upper Midwest and Great Lakes during the 29 January – 30 January 2019 period. The path and expansion of the cold arctic air was apparent in GOES-16 (GOES-East) Air Mass RGB images from the AOS site (above) — which first became evident over the Canadian arctic beginning on 28 January. The coldest air exhibited pale shades of yellow to beige in the Air Mass RGB images.

GOES-16 “Clean” Infrared Window (10.3 µm) images (below) also showed the southward expansion of arctic air into the north-central US — surface infrared brightness temperatures of -30 to -40ºC (darker blue to green enhancement) covered a large area. Such cold infrared brightness temperatures are normally associated with clouds in the middle to upper troposphere. Surface air temperatures of -20 to -40ºF were widespread, along with wind chill values of -40 to -70ºF, leading to numerous school and business closures. Two of the coldest official temperatures in the US on the morning of 30 January were -48ºF at Norris Camp, Minnesota and -44ºF at Bottineau, North Dakota (the high temperature in Bottineau on the previous day, 29 January, was only -26ºF); however, there were a few North Dakota Department of Transportation roadside sensors that reported low temperatures of -49ºF.

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, 28-30 January [click to play MP4 animation]

GOES-16 True Color RGB images (below) revealed a variety of multiple-band and single-band lake effect snow features as the arctic air moved across the Great Lakes. In addition, elongated and long-lived cloud bands created snow squall conditions across parts of Ohio and Pennsylvania.

GOES-16 True Color images [click to play MP4 animation]

GOES-16 True Color images [click to play MP4 animation]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 (at 1802 UTC) and Suomi NPP (at 1852 UTC) viewed using RealEarth (below) provided a closer look at the cloud bands across Ohio and Pennsylvania.

True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 (at 1802 UTC) and Suomi NPP (at 1852 UTC) [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 (at 1802 UTC) and Suomi NPP (at 1852 UTC) [click to enlarge]


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GOES-16 Clear-sky Total Precipitable Water, 1202 UTC on 30 January 2019 (Click to enlarge)

In addition to being extremely cold, the airmass over the Upper Midwest was extremely dry. The image above shows the Baseline GOES-R Total Precipitable Water product. The default AWIPS color enhancement has been modified to better capture the extreme dryness. Regions in light blue over western Minnesota and the eastern Dakotas curving through Iowa into northern Illinois show TPW values around 0.01″ ; green shadings over Wisconsin and eastern Minnesota correspond to values closer to 0.03″. In such dry airmasses, it is possible to see surface features in the infrared 7.3 low-level ABI Water Vapor Channel, Band 10, and the morning of 30 January was no exception, below. Surface features like rivers are notable in Illinois, for example. Even the heat island of the Minneapolis/St. Paul is apparent (albeit barely).  Surface features over northern Minnesota and Wisconsin aren’t quite so apparent, perhaps because of the increased amounts of moisture there.  There is likely less surface temperature contrast there, also, as rivers/lakes are more likely frozen.  It is the temperature contrast — as best exemplified by the Great Lakes shorelines — that allows features to appear in the Water Vapor imagery.

GOES-16 Low-Level Water Vapor Infrared (7.3 µm) Imagery, 1202 UTC on 30 January 2019 (Click to enlarge)

Weighting Functions (in real time, from this site) allow for an estimate of where information in different water vapor channels will be detected by the satellite. In the 0000 UTC 30 January 2019 example, below, from Chanhassen, MN (when total precipitable water there was 0.01″), a large signal is apparent from the low-level water vapor channel (7.3 µm); in fact, most of the information detected by the satellite was coming from the surface!  Even the mid-level water vapor (6.9 µm) had a component from the surface.  Weighting Functions for Davenport Iowa (The axis of the driest air shifted from near Chanhassen at 0000 UTC to near Davenport at 1200 UTC) at 0000 UTC and 1200 UTC are shown here; Note in the toggle that the level from which information is received by the satellite drops from 0000 to 1200 UTC as dry air moves in.

Clear-sky Weighting Function from Chanhassen MN, 0000 UTC on 30 January 2019 (Click to enlarge)

The GOES-16 Baseline Land Surface Temperature product, below, from 1200 UTC, shows many values at/below -45 F (purple shading) over Minnesota.  Dark blue values are around -25 F.  Note the relatively warm region over western Iowa, in cyan.  That part of Iowa lacks snowcover and exceptional cold rarely happens over bare ground.

GOES-16 Baseline Land Surface Temperature, 1202 UTC on 30 January 2019 (Click to enlarge)

===== 31 January Update =====

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with and without plots of hourly surface observations [click to play animation | MP4]

Across much of the Upper Midwest, the coldest temperatures occurred on the morning of 31 January. GOES-16 Infrared images (above) showed much of northeastern Minnesota and far northwestern Wisconsin — the low temperature of -56ºF at Cotton was only 4 degrees warmer than the all-time record low for Minnesota, and the low temperature of -47ºF at Butternut was 8 degrees warmer than the all-time record  low for Wisconsin (both of those records were set in early February 1996). The -56ºF in Cotton was not only the coldest temperature in the Lower 48 states on 31 January, but was also significantly colder than any official reporting station in Alaska that day. Also of interest in northeastern Minnesota, note the warmer plumes (darker blue enhancement; brighter greens are coldest) coming from power plants and industrial sites in the Iron Range area.

Farther to the south, GOES-16 Infrared images covering the Minnesota/Wisconsin/Iowa/Illinois region (below) also showed widespread cold surface brightness temperatures (shades of green). All-time record low temperatures were set at Cedar Rapids in Iowa (-30ºF) and at Moline (-33ºF) and Rockford (-31ºF) in Illinois. The cooperative observer at Mt. Carroll in northwestern Illinois reported a low of -38ºF — which, if verified, will establish a new all-time record minimum temperature for the state of Illinois.

GOES-16 "Clean" Infrared Window (10.3 µm) images, with plots of hourly surface observations [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.3 µm) images, with plots of hourly surface observations [click to play animation | MP4]

The recent stretch of days with cold air in place had helped the ice coverage to increase significantly in western Lake Superior — and the transition from northerly/northwesterly cold air advection to southwesterly warm air advection at the surface began to fracture a lot of this newly-formed lake ice (below).

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with plots of hourly surface reports [click to play animation | MP4]

Ice coverage had also increased across much of western/central Lake Erie, although areas of open water continued to supply latent heat to help generate lake effect snow bands (below).

GOES-16 "Red" Visible (0.64 µm) images, with plots of hourly surface reports [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) images, with plots of hourly surface reports [click to play animation | MP4]

A sequence of Terra MODIS True Color RGB images (below) showed substantial growth of nearshore ice in the southern end of Lake Michigan from 29 to 31 January.

Terra MODIS True Color RGB images [click to enlarge]

Terra MODIS True Color RGB images [click to enlarge]

.A summary of this cold outbreak was compiled by NWS Duluth, NWS La Crosse, NWS Twin Cities and NWS Grand Forks.

PyroCumulonimbus cloud in Australia

January 25th, 2019 |

Himawari-8

Himawari-8 “Red” Visible (0.64 µm, top), Shortwave Infrared (3.7 µm, middle) and Infrared Window (10.3 µm, bottom) images [click to play to animation | MP4]

JMA Himawari-8 “Red” Visible (0.64 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.3 µm) images (above) showed the development of a pyroCumulonimbus (pyroCb) cloud from a bushfire that was burning in the eucalypt forests of eastern Victoria, Australia on 25 January 2019. A rapid-scan “Target” sector was positioned over the region beginning at 0522 UTC, providing images every 2.5 minutes (instead of the routine 10-minute interval). Cloud-top infrared brightness temperatures became colder than -40ºC (the threshold for pyroCb classification) after 0230 UTC, and eventually cooled to around -55ºC (orange enhancement). This temperature roughly corresponded to an altitude around 12 km, according to nearby Melbourne rawinsonde data (plot | text).

A closer view of Himawari-8 “Red” Visible (0.64 µm) and Shortwave Infrared (3.7 µm) images (below) revealed the rapid southeastward run of the fire, as shown by the growth of the “hot spot” (black to red pixels) on Shortwave Infrared images. The darker gray appearance of the pyroCb cloud is due to the presence of smaller ice crystals at the cloud top — these smaller ice crystals are more efficient reflectors of incoming solar radiation, making the cloud tops appear warmer than those of conventional cumulonimbus. Vigorous updrafts driven by the intense heat of the fire limit the in-cloud residence time for ice crystal growth, which leads to smaller particles being ejected at the pyroCb cloud top.

Himawari-8 "Red" Visible (0.64 µm, left) and Shortwave Infrared (3.7 µm, right) images [click to play to animation | MP4]

Himawari-8 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.7 µm, right) images [click to play to animation | MP4]

In a comparison of VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images from Suomi NPP (at 0311 UTC) and NOAA-20 (at 0501 UTC) images viewed using RealEarth (below), cloud-top infrared brightness temperatures were in the -55 to -58ºC range (darker shades of orange).

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP (0311 UTC) and NOAA-20 (0501 UTC) images [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP (0311 UTC) and NOAA-20 (0501 UTC) images [click to enlarge]

Rope cloud in the East Pacific Ocean

January 16th, 2019 |
GOES-17

GOES-17 “Red” Visible (0.64 µm) image, with an overlay of the 12 UTC surface analysis [click to enlarge]

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

An 1802 UTC GOES-17 “Red” Visible (0.64 µm) image with an overlay of the 12 UTC surface analysis (above) revealed a well-defined rope cloud which stretched for nearly 1000 miles, marking the cold front position at the time of the image. Rope clouds can therefore be used to diagnose the exact location of the leading edge of a cold frontal boundary between times when surface analyses are available. In this case, the cold front was associated with a Hurricane Force low over the East Pacific Ocean on 16 January 2019 (surface analyses).

GOES-17 "Red" Visible (0.64 µm) images [click to play animation]

GOES-17 “Red” Visible (0.64 µm) images [click to play animation]

An animation of GOES-17 Visible images is shown above, with a zoomed-in version closer to the rope cloud displayed below.

GOES-17 "Red" Visible (0.64 µm) images [click to play animation]

GOES-17 “Red” Visible (0.64 µm) images [click to play animation]

An even closer look (below) showed that the rope cloud was only about 2-3 miles wide.

GOES-17 "Red" Visible (0.64 µm) images [click to enlarge]

GOES-17 “Red” Visible (0.64 µm) images [click to enlarge]

When the 18 UTC surface analysis later became available, a close-up comparison with the 1802 UTC GOES-17 Visible image (below) indicated that the northern portion of the cold front (as indicated by the rope cloud) was slightly ahead of — and the southern portion slightly behind — the smoothed cold frontal position of the surface analysis product.

1802 UTC GOES-17 "Red" Visible (0.64 µm) image, with an overlay of the 18 UTC surface analysis [click to enlarge]

1802 UTC GOES-17 “Red” Visible (0.64 µm) image, with an overlay of the 18 UTC surface analysis [click to enlarge]

NOAA-15 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 1617 UTC [click to enlarge]

NOAA-15 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 1617 UTC [click to enlarge]

1-km resolution AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images of the rope cloud were captured by NOAA-15 at 1617 UTC (above) and by NOAA-18 at 1710 UTC (below). Along the northeastern portion of the rope cloud, there were a few convective clouds which exhibited cloud-top infrared brightness temperatures as cold as -55 to -60ºC (darker shades of red) and were tall enough to be casting shadows due to the low morning sun angle.

NOAA-18 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images [click to enlarge]

NOAA-18 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 1710 UTC [click to enlarge]


===== 17 January Update =====

GOES-17 True Color RGB images [click to play animation | MP4]

GOES-17 True Color RGB images [click to play animation | MP4]

On the following day, another rope cloud (one that was more fractured) was seen moving across Hawai’i as a cold front passed the island of Kaua’i — the southeastward progression of the rope cloud was evident on GOES-17 True Color Red-Green-Blue (RGB) images (above)  from the UW AOS site.

Surface observations plotted on GOES-17 Visible images (below) showed the wind shift from southwest to north as the cold front moved through Lihue on Kauwa’i around 00 UTC.

GOES-17

GOES-17 “Red” Visible (0.64 µm) images, with plots of surface reports [click to play animation | MP4]

===== 18 January Update =====

Suomi NPP VIIRS Day/Night Band (0.7 µm) image, with and without buoy observations [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) image, with and without buoy observations [click to enlarge]

Not all rope clouds are associated with cold fronts; with ample illumination from the Moon — in the Waxing Gibbous phase, at 90% of Full — a Suomi NPP VIIRS Day/Night Band (0.7 µm) image (above) provided a “visible image at night” of a rope cloud in the northern Gulf of Mexico which highlighted a surface wind shift axis.

A sequence of VIIRS Day/Night Band images from NOAA-20 and Suomi NPP (below) showed the movement of the rope cloud during a time span of about 1.5 hours.

NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]