Severe thunderstorms in Arkansas

April 11th, 2022 |

GOES-16 “Clean” Infrared Window (10.35 µm) images, with time-matched SPC Storm Reports plotted in cyan [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (above) include time-matched SPC Storm Reports plotted in cyan — and showed several tornadoes and hail up to 4.50 inches in diameter across Arkansas early in the evening on 11 April 2022. One of the larger tornadoes prompted the issuance of a Tornado Emergency:

NUCAPS Profiles before an historic snow in Portland Oregon

April 11th, 2022 |
GOES-16 Band 13 infrared (10.3 µm) imagery, 0941-1346 UTC on 11 April 2022 (Click to enlarge)

April 11 2022 saw the first measurable snowfall ever in April at the Portland OR airport (WFO Portland Tweet), where records have been kept since 1940. The GOES-16 animation above shows the weather system responsible for the weather.

NOAA-20 overflew the west coast shortly after 1000 UTC (map of the orbit, from this website), and NUCAPS profiles derived from the CrIS and ATMS instruments on board helped define the cold airmass just offshore. The toggle below shows two soundings (green suggesting that the retrieval converged to a solution) just along the shoreline; 850-mb temperatures are -5oC and -4oC at the northern and southern profiles, respectively; the diagnosed freezing levels at both locations are higher than 2000′.

NUCAPS profiles from NOAA-20 at two locations off the west coast of the United States, 1019 UTC on 11 April 2022 (Click to enlarge)

The toggle below shows Sounding Availability points (zoomed in) and diagnosed freezing levels farther offshore, suggesting colder air out over the open ocean.

Sounding Availability points, and diagnosed freezing levels, ca. 1020 UTC on 11 April 2022 (click to enlarge)

Gridded NUCAPS are available in AWIPS — and also at this site created by NASA SPoRT (and at RealEarth). The toggle below shows gridded 850- and 700-mb temperatures from the NOAA-20 overpass. The coldest air is shown over the Pacific Ocean at 1017 UTC.

Gridded 850- and 700-mg temperatures, 1017 UTC on 11 April 2022 (Click to enlarge)

NUCAPS profiles and gridded NUCAPS fields can give timely observations over large data voids (such as the Pacific Ocean) in advance of high-impact weather events.