A storm dropped historic snow amounts over parts of northern Pennsylvania, upstate New York and New England on 16-17 December 2020 (Places around Binghamton NY, for example, received more than 40″ of snow as shown in this map from this site.  Click here to see the Binghamton Radar loop during the storm).  The VIIRS True-Color image from ~1800 UTC on 17 December, above (created at the Direct Broadcast site at CIMSS, and available via LDM feed to NWS Forecast offices), shows the storm south of Cape Cod, and snow on the ground in the Mid-Atlantic states (the Great Valley in Virginia, Maryland and Pennsylvania is particularly apparent)

View only this post Read Less

GOES-16 (GOES-East) Mid-level (6.9 µm) Water Vapor images (above) showed 2 important signatures associated with the an intense Nor’easter that moved northeastward along the US East Coast during the 16 December – 17 December 2020 period (surface analyses): (1) the development of a baroclinic leaf signature related to the initial batch of heavy snowfall, and (2) a broad deformation zone that lingered behind and slowly pivoted across the Northeast US, helping to prolong heavy snowfall.

1-minute Mesoscale Domain Sector GOES-16 “Red” Visible (0.64 µm) images displayed the well-defined center of the Nor’easter as it moved eastward off the coast of Long Island, Rhode Island and Massachusetts on 17 December (below).

Other features of interest included the development of clusters of parallel convective billow clouds over parts of Massachusetts, New Hampshire and Maine on 17 December, near the rear edge of the departing Nor’easter — a comparison of NOAA-20 VIIRS Visible (0.64 µm), Near-Infrared (1.61 µm) and Infrared Window (11.45 µm) images (below) provided a detailed view of these billow clouds at 1639 UTC.

A time-matched comparison of Visible, Near-Infrared and Infrared Window images from NOAA-20 and GOES-16 (below) demonstrated (1) the advantage of improved spatial resolution for detecting such small-scale features, and (2) the slight northward shift on their apparent location on GOES-16 images, due to parallax.

1-minute GOES-16 Visible, Near-Infrared, Infrared Window and Day Cloud Phase Distinction RGB images (below) showed the development and propagation of these convective billows during the 1600-1800 UTC period. A curious aspect of these billows was the fact that even though they exhibited colder infrared brightness temperatures than the surrounding glaciated clouds, the parallel billow band cloud tops appeared to be composed primarily of supercooled water droplets (brighter white on the Near-Infrared and Day Cloud Phase Distinction RGB images).

Additional information and images of this Nor’easter can be found at this blog post and on the Satellite Liaison Blog.

Here's a quick recap of the snowfall from this week's nor'easter. An extremely heavy band of snow lead to 40+ inch reports in four different states: PA, NY, VT, and NH. Two potential state records for 24-hour snowfall would require additional verification. https://t.co/1wii3BsFlz pic.twitter.com/RSsxEZloaA

— NWS Weather Prediction Center (@NWSWPC) December 18, 2020

View only this post Read Less

Himawari-8 Clean Window Infrared (10.41 µm) imagery, 0000 UTC 14 December to 0000 UTC 16 December 2020 (Click to animate)

Himawari-8 Clean Window Infrared (10.41 µm) imagery (courtesy the Japanese Meteorological Agency, JMA) from 14-15 December 2020 (click here for an animated gif) show the development of a potent storm with an obvious clear and large eye by 0000 UTC on 16 December. The Joint Typhoon Warning Center notes: ” TC 05P HAS RAPIDLY INTENSIFIED 50 KNOTS OVER THE PAST 24 HOURS, FROM 85 KNOTS AT 14/18Z TO 135 KNOTS AT 15/18Z.” Yasa further intensified to a Category 5 tropical cyclone at 0000 UTC on 16 December.

2.5-minute rapid scan #Himawari8 Infrared images of Category 5 (as of 0000 UTC) Cyclone #Yasa northwest of Fiji: https://t.co/CcSMlqeInA pic.twitter.com/zZ4Vl4DalM

— Scott Bachmeier (@CIMSS_Satellite) December 16, 2020

Visible imagery from GOES-17 and Himawari-8, (mp4 animation below, click here for an animated gif, and here for a full-sized mp4), during the day on 16 December show a well-developed storm with a clear eye.

Stereoscopic view of Cyclone Yasa, 1800 UTC 15 December to 0550 UTC 16 December 2020. Click to animate. GOES-17 Visible imagery on the left, Himawari imagery on the right

A storm-centered view of the storm is shown below. Click here for the full-sized mp4, and here for an animated gif.

Storm-centered stereoscopic view of Cyclone Yasa, 1800 UTC 15 December to 0550 UTC 16 December 2020. Click to animate. GOES-17 Visible imagery on the left, Himawari imagery on the right

The animation below is also storm-centered, but zoomed in on the eye of the storm.  Click here for a full-sized mp4, and here for an animated gif

Storm-centered stereoscopic view of the eye of Cyclone Yasa, 1800 UTC 15 December to 0550 UTC 16 December 2020. Click to animate. GOES-17 Visible imagery on the left, Himawari imagery on the right

Forecast models take this strong cyclone over Fiji later this week. Refer to the JTWC, to the RSMC in Fiji or the SSEC Tropical web site for more information.

View only this post Read Less

As was seen 2 days earlier, a plume of blowing dust developed across the Texas Panhandle in the wake of a cold frontal passage, and was transported southeastward across western Texas on 15 December 2020 — GOES-16 (GOES-East) Dust RGB images (above) displayed signatures of this airborne dust (brighter shades of pink).

GOES-16 True Color RGB images created using Geo2Grid (below) showed the tan-colored signature of blowing dust increase during the afternoon hours leading up to sunset. A few of the point sources of the dust appeared to beds lake beds near the Texas/New Mexico border, areas which were experiencing extreme to exceptional drought conditions.

View only this post Read Less