Winter storm affecting the southern Plains to the Mid-Atlantic

December 10th, 2018 |

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly plots of surface weather type [click to play MP4 animation]

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly plots of surface weather type [click to play MP4 animation]

A large storm produced significant winter weather impacts from the southern Plains to the Mid-Atlantic states during the 07 December10 December 2018 period. GOES-16 (GOES-East) Mid-level Water Vapor (6.9 µm) images (above) showed the progression of the storm during that 3-day interval.

As much as 10-11 inches of snow fell in the Lubbock, Texas area during 07-08 December. A sequence of  Suomi NPP VIIRS Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (below) showed the snow cover melting from 09-10 December. Snow cover absorbs radiation at the 1.61 µm wavelength, so it appears very dark on those images.

Suomi NPP VIIRS Visible (0.64 µm) and Near-Infrared

Suomi NPP VIIRS Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images [click to enlarge]

Portions of northern and northeastern Arkansas received ice accrual of up to 0.5 inches due to freezing rain — those areas with snow and ice on the ground can be seen in a comparison of Suomi NPP VIIRS Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (below).

Suomi NPP VIIRS Visible (0.64 µm) and Near-Infrared "Snow/Ice" (1.61 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images [click to enlarge]

Significant snowfall resulted across the central Appalachians and Mid-Atlantic, especially for so early in the winter season — 1-minute Mesoscale Domain Sector “Red” Visible (0.64 µm) images (below) revealed embedded convective elements and banding that helped to enhance snowfall rates across that region on 09 December. GLM Groups are also plotted on the images; however, there was no satellite signature of lightning associated with the convective elements until 2130 UTC in north-central North Carolina.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with plots of hourly surface weather type in yellow and GLM Groups in red [click to play MP4 animation]

 

===== 11 December Update =====

GOES-16

GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images [click to play animation | MP4]

Once clouds cleared the eastern US on 11 December, the areal coverage of snow cover across the central Appalachians and Mid-Atlantic states could be seen in a comparison of GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (above). Note the darker areas seen on 1.61 µm imagery over parts of eastern Kentucky and also from north-central North Carolina into south-central Virginia: those are areas where the snow cover also received a thin glaze of ice from a period of freezing drizzle/rain.

Industrial and ship plumes in supercooled clouds

December 4th, 2018 |

MODIS and VIIRS

MODIS and VIIRS “Fog/stratus” BTD images [click to enlarge]

A sequence of nighttime MODIS and VIIRS “Fog/stratus” infrared Brightness Temperature Difference (BTD) images (above) revealed long plumes (darker shades of red) streaming southwestward for over 200 miles from their industrial point sources in the Mesabi Range of northeastern Minnesota on 03 December 2018.

During the subsequent daytime hours, a comparison of GOES-16 (GOES-East) “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (below) showed signatures of these Mesabi Range plumes along with others emanating from industrial or power plant sources. A few ship tracks were also apparent across Lake Superior.

Particles emitted from the exhaust stacks at power plants and industrial sites (as well as ships) can act as efficient cloud condensation nuclei, which causes the formation of large numbers of supercooled water droplets having a smaller diameter than those found within the adjacent unperturbed supercooled clouds — and these smaller supercooled cloud droplets are better reflectors of incoming solar radiation, thereby appearing brighter in the Near-Infrared and warmer (darker gray) in the Shortwave Infrared images.

GOES-16

GOES-16 “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

On the following night, another sequence of MODIS and VIIRS “Fog/stratus” infrared Brightness Temperature Difference (BTD) images (below) highlighted a number of industrial and power plant plumes across Minnesota, northern Wisconsin and the Upper Peninsula of Michigan. The curved shape of many of these plumes resulted from boundary layer winds shifting from northerly to westerly as the night progressed.

MODIS and VIIRS "Fog/stratus" BTD images [click to enlarge]

MODIS and VIIRS “Fog/stratus” BTD images [click to enlarge]

During the following daytime hours on 04 December, a comparison of VIIRS Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images (below) showed 2 plume types across eastern Nebraska. There were several of the brighter/warmer plumes similar to those noted on the previous day across Minnesota/Wisconsin/Michigan — but one large plume originating from industrial sites just east of Norfolk (KOFK) had the effect of eroding the supercooled cloud deck via glaciation (initiated by the emission of particles that acted as efficient ice nuclei) and subsequent snowfall. This is similar to the process that creates aircraft “distrails” or “fall streak clouds” as documented here, here and here.

VIIRS Visible (0.64 µm), Near-Infrared

VIIRS Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]


Farther to the east over Ohio and Pennsylvania, another example of the 2 plume types was seen (below) — one plume originating from an industrial site near Cleveland was glaciating/eroding the supercooled cloud and producing snowfall, while another bright/warm supercooled droplet plume was moving southeastward from a point source located west of Indiana County Airport KIDI.

The Cleveland plume was captured by an overpass of the Landsat-8 satellite, with a False Color Red-Green-Blue (RGB) image viewed using RealEarth providing great detail with 30-meter resolution (below). A small “overshooting top” can even be seen above the industrial site southeast of Cleveland, with the swath of glaciated and eroding cloud extending downwind (to the southeast) from that point.

Landsat-8 False Color RGB image [click to enlarge]

Landsat-8 False Color RGB image [click to enlarge]

Coincidentally, Landsat-8 also captured another example of a glaciating cloud plume downwind of the Flint Hills Oil Refinery south of St. Paul, Minnesota on 03 December (below). The erosion/glaciation of supercooled cloud extended as far south as Albert Lea, Minnesota. Similar to the Cleveland example, a small “overshooting top” was seen directly over the plume point source.

Landsat-8 False Color RGB image [click to enlarge]

Landsat-8 False Color RGB image [click to enlarge]

===== 08 December Update =====

The effect of this industrial plume glaciating and eroding the supercooled water droplet clouds over northern Indiana was also seen in a comparison of Terra MODIS Visible (0.65 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.0 µm) images (below).

Terra MODIS Visible (0.65 µm), Near-Infrared

Terra MODIS Visible (0.65 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.0 µm) images [click to enlarge]

===== 09 December Update =====



During the following daytime hours, GOES-16 “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.3 µm) images (below) showed a number of plumes from industrial sites (many of which were likely refineries) streaming southeastward and eastward over the Gulf of Mexico on 09 December. Note the lack of a plume signature in the 10.3 µm imagery.
GOES-16 "Red" Visible (0.64 µm), Near-Infrared "Snow/Ice" (1.61 µm), Near-Infrared "Cloud Particle Size" (2.24 µm), Shortwave Infrared (3.9 µm) and "Clean" Infrared Window (10.3 µm) images [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

The first -40º temperature of the winter in Alaska

November 24th, 2018 |

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

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

A sequence of Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images centered over the North Slope of Alaska (above) showed a few patches of thin stratus cloud drifting westward on 24 November 2018. Ample illumination from the Moon — which was in the Waning Gibbous phase, at 98% of Full — maximized the “visible image at night” capability of the Day/Night Band. A faster animation of Infrared images helped to emphasize the westward motion of multi-year drift ice in the Beaufort Sea as it collided with the growing wedge of first-year land-fast ice off the northeast coast of Alaska.

In areas with deeper snow cover that remained generally cloud-free for long periods of time, temperatures at first-order stations dropped into the -20s and -30s F; a low of -35ºF was recorded at Nuiqsut (PAQT). A closer look at the 2314 UTC Infrared image (below) revealed surface brightness temperatures as cold as -47ºC or -53ºF (lighter shades of yellow) in the valleys near Galbraith Lake (PAGB).

Suomi NPP VIIRS Infrared Window (11.45 µm) image at 2314 UTC [click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) image at 2314 UTC [click to enlarge]

The RAWS site at Umiat Airfield (PAUM) registered a minimum temperature of -40ºF (hourly summary) at 2123 UTC on 24 November (below) — this was the first reliable -40º temperature of the 2018/2019 Winter season in Alaska. Farther to the east, the HADS site at Sagavanirktok recorded a low of -44F, but that max/min temperature data was flagged as being suspect (red) by Mesowest quality control.

Minimum and maximum temperatures for the 24-hour period ending at 20 UTC on 25 November [click to enlarge]

Minimum and maximum temperatures for the 24-hour period ending at 20 UTC on 25 November [click to enlarge]

Increasing ice concentration in Hudson Bay

November 21st, 2018 |

Sea ice concentration derived from AMSR2 data, 06-21 November [click to play animation | MP4]

Daily sea ice concentration derived from AMSR2 data, 06-21 November [click to play animation | MP4]

After increasingly colder air began moving from eastern Nunavut across Hudson Bay beginning on 06 November (surface analyses), the daily sea ice concentration as derived from GCOM-W1 AMSR2 data (source) began to increase in the northern half of Hudson Bay (above) — especially after 15 November once mid-day (18 UTC) temperatures colder than -20ºF were seen at reporting stations along the northwest coast.

A sequence of daily Terra/Aqua MODIS True Color Red-Green-Blue (RGB) images (source) showed signatures of the increasing of ice coverage.

Terra/Aqua MODIS True Color RGB images, 06-21 November [click to play animation | MP4]

Daily Terra/Aqua MODIS True Color RGB images, 06-21 November [click to play animation | MP4]

A toggle between Terra MODIS True Color and False Color RGB images on 21 November (below) confirmed that much of the northern half of Hudson Bay contained ice — snow/ice (as well as ice crystal clouds) appear as darker shades of red in the False Color image (in contrast to the cyan shades of supercooled water droplet clouds).

Terra MODIS True Color and False Color RGB images on 21 November [click to enlarge]

Terra MODIS True Color and False Color RGB images on 21 November [click to enlarge]

19 November maps of Ice Concentration, Ice Stage and Departure from Normal via the Canadian Ice Service (below) further characterized this ice formation, which was ahead of normal for the central portion of Hudson Bay.

Ice Concentration [click to enlarge]

Ice Concentration [click to enlarge]

Ice Stage [click to enlarge]

Ice Stage [click to enlarge]

Ice Concentration Departure [click to enlarge]

Ice Concentration Departure [click to enlarge]