Nearshore ice motion in the Beaufort Sea

June 21st, 2022 |

Suomi-NPP VIIRS Visible (0.64 µm) images [click to play animated GIF | MP4]

Suomi-NPP VIIRS Visible (0.64 µm) images (above) showed a variety of Beaufort Sea ice floe motion within the nearshore waters of Alaska and Yukon during the 20-21 June 2022 period. Just north of Utqiavik (or Barrow, PABR), a sharp “shear line” was seen on 20 June — with a narrow line of ice flows moving east-northeastward, directly adjacent to the the pack ice that was moving westward.

Farther to the east (in the bottom right corner of this satellite scene), a fracture in the fast ice off the Yukon coastline led to the separation of a large ice floe on 21 June — which then drifted west-northwestward. Of note were the unusually warm surface air temperatures at stations near/along the northern coastline of Yukon, with some temperature readings rising into the upper 50s and low 60s F.

Cross-sections using gridded NUCAPS data in AWIPS

June 21st, 2022 |
NOAA-20 Day Night Band visible imagery (0.70) along with NUCAPS Sounding Availability points, ca. 19z on 21 June 2022 (Click to enlarge)

Gridded NUCAPS data, available from NOAA-20 data within AWIPS, can be used to construct cross-sections in AWIPS. The image above includes an editable baseline J-J’ (one of 10 different lines that can be used for data in AWIPS) from Minnesota into Indiana, roughly perpendicular to a line of broken cumulus over Wisconsin and Iowa.

Equivalent Potential Temperature along line J-J’ as indicated in imagery above (Click to enlarge)

The cross section of equivalent potential temperature, above, shows very warm temperatures over the southern portions of the cross section, with theta-e values around 350 K. Potential Instability, i.e., theta-e values decreasing with height, is widespread along the cross-section. The broken cloud field in the VIIRS imagery on top eventually did initiate convection, as shown in this radar capture from 0012 UTC on 22 June.

How do you create the cross-sections in AWIPS? Use the Volume Browser, as shown in the screen capture below. Select ‘Cross Section’ (vs. ‘Plan view’, for example) from the choices in the Volume Browser right next to ‘File’, ‘Edit’ and ‘Tools’, then choose ‘GriddedNUCAPS’ under ‘Sources’, and choose the correct Plane — as one of the Specified Lines you have previously moved in AWIPS; then choose the variable (possibilities are shown in the image; I chose Equiv Pot Temp).

Volume Browser presentation while creating Cross-Sections using gridded NUCAPS data (Click to enlarge)

Imagery in this blog was created using a cloud instance of AWIPS from the TOWR-S group within NOAA/NWS. Thank you!

VIIRS composite flood products over Bangladesh and India

June 21st, 2022 |

The five-day composite of the VIIRS flood product is just one flood product that can be viewed in RealEarth. VIIRS is an instrument aboard SNPP and NOAA-20, which are low earth orbiting satellites. This means that while only two daytime observations may be retrieved per day over a given region, the spatial resolution of 375-m is quite highly resolved. VIIRS flood composites, such as the five-day composite, provide the “maximal flood extent” during flood events. More information about VIIRS and other satellite flood products can be found here.

In areas of Bangladesh and northwest India, persistent rains have caused recent heavy flooding. Millions of people have already been displaced and the flooding is forecast to continue. The VIIRS five-day flood product composite over a six-day time period can be seen below, with the 7-day CMORPH2 satellite-derived precipitation accumulation product. Comparing the images, the spatial placement of flooding with accumulated precipitation coincides well.

Daily images of the five-day VIIRS flood product composite from 6-15-2022 to 6-20-2022 over Bangladesh and Northeastern India. The product estimates the severity of river flooding over the last five days [click to enlarge].
CMORPH2 accumulate precipitation from 6-20-2022 over the same area. This product represents the approximate precipitation (rainfall) accumulation over the last seven days [click to enlarge].
Convective storms occurring over Bangladesh and Northeast India on 6-19-2022 from 00:00Z to 15:50Z as seen from the Advanced Himawari Imager (AHI). This animation was created using CSPP’s geo2grid software.