1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Day Cloud Phase Distinction RGB images (above) displayed a narrow band of glaciated (brighter shades of green) clouds that produced snow squalls as it moved rapidly eastward across Pennsylvania on 19 February 2022. Due to the fast motion of the snow squall band, resultant snowfall amounts were generally 1 inch or less at most locations — but the visibility often quickly dropped to near zero due to intense snowfall rates and gusty winds. For example, as the snow squall moved through State College just after 16 UTC, the surface visibility went from 10 miles to less than 1/4 mile and then back to 10 miles within 30 minutes (below).

Here’s a timelapse of the snow squall as it passed through State College, shot from our office window #PAwx pic.twitter.com/cJfpjXTCxm

— NWS State College (@NWSStateCollege) February 19, 2022

In far eastern Pennsylvania, snow squalls caused a 50-vehicle pileup on Interstate 81, closing the section between the McAdoo and Hazelton exits for about 6 hours (media report) — the accident occurred as the snow squall band was moving through that area around 18 UTC, as seen in a closer view of GOES-16 Day Cloud Phase Distinction RGB images (below) .

In a before/after toggle between GOES-16 Day Cloud Phase Distinction RGB images at 1724 UTC and 1900 UTC below), the dark blue signature of bare ground in the Hazelton area prior to the arrival of the snow squall was replaced by a darker green signature of snow-covered ground.

As was seen with the snow squall passage at State College, a brief but rapid drop in surface visibility occurred at Hazelton (below) as the squall passed through around 18 UTC.

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The animation above, of the Day Cloud Phase Distinction RGB, shows bands of snow showers/squalls rotating cyclonically through northern Minnesota and northwestern Wisconsin, to the south of a strong cyclone over northern Minnesota and northwestern Ontario (link to map from 1800 UTC on 18 February). The tops of these clouds are fairly low — in the RGB they have a periwinkle color in contrast to the orange/red color of the higher cirrus to the south. The RGB also allows for good contrast between the clouds and the clear snow-covered grounds (with greenish tones) to the west.

A potency of the upper air system supporting the surface cyclone is highlighted in the Ozone Anomaly fields from gridded NUCAPS data, shown below. Anomalies of 120-140 dobson Units are present.

The National Weather Service in Duluth MN issued a series of Snow Squall Warnings; the first one, valid until 1945 UTC, is shown below (taken from this tweet); sequential tweeted Warnings are here (valid until 2015 UTC), here (valid until 2100 UTC), here (valid until 2145 UTC) and here (valid until 2215 UTC). (Note, WFO ARX — in Lacrosse, WI, is issuing Snow Squall warnings for this system as well!)

Three radars for this event are shown below: 1907, 1937 and 2007 UTC.

VIIRS imagery (available from the CIMSS LDM feed) over the Duluth Area afforded a high-resolution view of this event. The toggles below show True and False Color imagery at 1838 UTC (from Suomi NPP) and at 1929 UTC (from NOAA-20) At 1838 UTC, the clouds producing the snow — between Moose Lake and Floodwood — do not stand out. They are much more noticeable in the 1929 UTC image, southeast of Duluth and northwest of Solon Springs.

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What was the effect on visibility? That is shown in the animation below with a 10-minute time step. Note how Duluth goes from southwesterly winds with light snow and 5- to 10- mile visibility to strong northwest winds (gusts to 45 knots) and reduced visibilities as the squall moves through.

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As this front moved through southern Wisconsin, it generated lightning, as shown in the animation below (from this website).

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A storm named Eunice has developed over the British Isles and is causing severe winds, up to 122 mph observed at the surface. The storm is associated with a very active jet stream in the North Atlantic. Eunice follows another storm, Dudley, that hit England, Ireland, and Scotland on Wednesday 2/16/22 and brought heavy winds and flooding.

#SATELLITE SPOTLIGHT: Europe's #Meteosat11 has been tracking a powerful system moving across the British Isles today. One of the worst storms to hit the U.K. in a generation, #StormEunice is producing a large storm surge, winds up to 100 mph, and widespread power outages. pic.twitter.com/tKZw9QHCZF

— NOAA Satellites – Public Affairs (@NOAASatellitePA) February 18, 2022

#StormEunice as it approached Ireland overnight.https://t.co/Xg3aMJlyuS pic.twitter.com/P3dwoBffCD

— Met Éireann (@MetEireann) February 18, 2022

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ECMWF produced a short write-up on this storm, and two others that week (link).

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GOES-16 (GOES-East) Dust RGB and Split Window Difference (10.3-12.3 µm) images (above) revealed a pulse of blowing dust (or haboob) that was created by strong surface outflow from collapsing thunderstorms near the California/Nevada border on 15 February 2022. Much of this wind-lofted dust (appearing as brighter shades of magenta in Dust RGB images, and brighter shades of yellow to green in Split Window Difference images) was then channeled southward through the lower elevations of Death Valley, California — reducing the visibility to zero and causing power outages (Local Storm Report).

A toggle between GOES-16 Dust RGB and Split Window Difference images at 2156 UTC (along with topography) is shown below.

The blowing dust was also evident in GOES-16 True Color RGB images created using Geo2Grid (below) .

Yes! It is a haboob and we actually spotted it on our visible satellite imagery as well! Dust storm warning continues for eastern Inyo County including Death Valley NP! #cawx https://t.co/OCLVnRHETf

— NWS Las Vegas (@NWSVegas) February 15, 2022

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