Valley fog and mountain snow in the Catskills of New York

May 1st, 2018 |

As pointed out by NWS Binghamton, valley fog and higher-elevation snow cover was apparent on GOES-16 (GOES-East) Visible imagery in the Catskills of southeastern New York on the morning of 01 May 2018. A closer view comparing GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (below) showed the dissipation of the valley fog, followed by the melting of the snow cover in higher terrain (snowfall amounts of up to 3-4 inches fell in the area on 29 April). The Snow/Ice imagery was helpful in discriminating between the brighter valley fog features and the darker snow cover.

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and Near-Infrared “Snow/Ice” (1.61 µm, right) images, with hourly plots of surface reports [click to play animation | MP4]

A 250-meter resolution Terra MODIS True-color Red-Green-Blue (RGB) image acquired from the SSEC Direct Broadcast ground station (below) showed the remaining snow cover over the Catskills (near the center of the image) at 1539 UTC.

Terra MODIS True-color image [click to enlarge]

Terra MODIS True-color image [click to enlarge]

Heavy snow across southern Minnesota, northern Iowa and southern Wisconsin

April 18th, 2018 |

24-hour snowfall ending at 12 UTC on 19 April [click to enlarge]

24-hour snowfall ending at 12 UTC on 19 April [click to enlarge]

The map above shows a band of heavy snow that fell across southern Minnesota (as much as 11.0 inches), northern Iowa (as much as 12.0 inches) and southern Wisconsin (as much as 9.4 inches) on 18 April 2018.

Animations of 1-minute Mesoscale Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm), “Clean” Infrared Window (10.3 µm) and “Low-level” Water Vapor (7.3 µm) images (below) showed the formation of convective elements and banding along the southern edge of the colder cloud shield — snowfall rates were enhanced when these convective features moved overhead, and thundersnow was noted at some locations in northern Iowa and southern Wisconsin.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with hourly surface weather type plotted in cyan [click to play MP4 animation]

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with hourly surface weather type plotted in yellow [click to play MP4 animation]

GOES-16

GOES-16 “Low=level” Water Vapor (7.3 µm) images, with hourly surface weather type plotted in cyan [click to play MP4 animation]

In south-central Wisconsin, Madison (KMSN) received 7.2 inches of snowfall, which set a new record for daily snowfall (and helped to make April the snowiest month of the 2017/2018 winter seeason). In addition, the daily maximum temperature was only 33 ºF, which was a record low maximum for the date. Over the southwestern part of the city, a cluster of GOES-16 Geostationary Lightning Mapper (GLM) Groups was detected from 1918 to 1919 UTC (below; courtesy of Dave Santek, SSEC) — the GOES-16 Visible image at that time did display a textured cloud top appearance characteristic of embedded convection across southern Wisconsin.

GOES-16 GLM Groups [click to enlarge]

GOES-16 GLM Groups [click to enlarge]

===== 20 April Update =====

GOES-16 true-color (daytime) and Infrared Window (10.3 µm, nighttime) images [click to play MP4 animation]

GOES-16 natural-color RGB (daytime) and Infrared Window (10.3 µm, nighttime) images [click to play MP4 animation]

A fast animation of GOES-16 natural-color Red-Green-Blue (RGB) images (above) revealed the rapid rate of snow melt — especially on 19 April — along the southern edge of the snow cover (where lighter amounts of snow fell). The effect of the high late-April sun angle also played a role in the rapid snow melt.

Some satellite signatures of Winter remaining on 01 April

April 1st, 2018 |

GOES-16

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

Some remnant signatures of Winter could be seen on 01 April 2018 — the first were seen  on GOES-16 (GOES-East) GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice (1.61 µm) over North Dakota and South Dakota, in the form of snow cover and snow/ice on parts of the Missouri River (above). With the high April sun angle, the lesser snow cover over northern South Dakota melted rather quickly, and the southern edge of the deeper snow cover in southern North Dakota also receded during the day.

Farther to the east, the motion and breakup of ice in Green Bay was evident on GOES-16 “Red” Visible (0.64 µm)  images (below).

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play animation]

The March of Cyclones in a ‘Foureaster’ Animation

March 27th, 2018 |

GOES-16 ABI Imagery from 28 February through 24 March 2018 at 15-minute time steps. CIMSS Natural Color imagery is shown during the day, a blend of GOES-16 ABI Shortwave (3.9 µm) and Longwave (10.3 µm) Infrared imagery is shown at night. (Click to open YouTube animation)

Four weeks of GOES-16 Full-Disk imagery, spanning 28 February to 24 March at a 15-minute interval, showing four Nor’easters, are available via the image above at YouTube.  The imagery shows CIMSS Natural Color during the day and a blend of GOES-16 ABI Shortwave (3.9 µm) and Longwave (10.3 µm) Infrared imagery at night.

The original mp4 (200 megabytes) is available for download here.