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Tropical disturbance near Fiji

GOES-17 ABI and GLM imagery (from this NOAA STAR website), above, over the southern Pacific Ocean show a region of potential tropical cyclogenesis to the west of Fiji, near the western boundary of this mapping. This Invest Area has been percolating for much of the week. Despite low values of shear (shown below,... Read More

GOES-17 Geocolor imagery and Flash Extent Density, 1506-1911 UTC on 7 January 2022 (Click to enlarge)

GOES-17 ABI and GLM imagery (from this NOAA STAR website), above, over the southern Pacific Ocean show a region of potential tropical cyclogenesis to the west of Fiji, near the western boundary of this mapping. This Invest Area has been percolating for much of the week. Despite low values of shear (shown below, from this website) and warm sea-surface temperatures, intensification to a tropical depression has not yet occurred (see this discussion from the Joint Typhoon Warning Center). However, GLM observations of Flash Extent Density (FED) do show occasional lightning events within the developing system.

Diagnosed wind shear, 1800 UTC on 07 January 2022 (Click to enlarge)

Upper-level water vapor imagery (GOES-17 Band 8, at 6.19 µm), below, from 1940 UTC, shows a distinct cirrus overcast at about 17 S, 172 E. Substantial dry air is not indicated in the water vapor imagery, nor in a MIMIC TPW mapping from 1200 UTC (downloaded from here), shown below.

Upper-level water vapor imagery (GOES-17 Band 8, 6.19 µm), 1930 UTC on 7 January 2022 (Click to enlarge)
MIMIC Total Precipitable Water fields, 1200 UTC on 7 January 2022 (Click to enlarge)

Scatterometry over this system on 7 January (downloaded from this website), show an increase in symmetry to the storm between the HY-2B overpass at 0630 UTC and the HY-2C overpass at 1330 UTC. For more information on this system over the weekend, refer to the SSEC/CIMSS Tropical Website, the Joint Typhoon Warning Center, and the Fiji Meteorological Service.

Scatterometery over the south Pacific, 0630 and 1330 UTC on 7 January 2022 (Click to enlarge)

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Blowing snow across parts of Minnesota and Iowa

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Day Snow-Fog RGB images (above) displayed NW-to-SE oriented horizontal convective roll cloud features that highlighted areas where blowing snow was reducing surface visibility across southeastern Minnesota and northwestern Iowa during the afternoon hours on 06 January 2022. The visibility dropped to 2 miles at Alberta Lea,... Read More

GOES-16 “Red” Visible (0.64 µm) and Day Snow-Fog RGB images [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Day Snow-Fog RGB images (above) displayed NW-to-SE oriented horizontal convective roll cloud features that highlighted areas where blowing snow was reducing surface visibility across southeastern Minnesota and northwestern Iowa during the afternoon hours on 06 January 2022. The visibility dropped to 2 miles at Alberta Lea, Minnesota (KAEL) — which is at the junction of Interstates 35 and 90 — at 21 UTC. 

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Winter storm affecting the Mid-Atlantic states

GOES-16 (GOES-East) Air Mass RGB images (above) showed the signature of a Potential Vorticity (PV) Anomaly — denoted by shades of red to pink within the comma head portion of the storm — which likely aided in enhancing precipitation rates within a midlatitde cyclone (surface analyses) as it moved across the region on... Read More

GOES-16 Air Mass RGB images, with and without contours of RAP40 model PV1.5 pressure [click to play animated GIF | MP4]

GOES-16 (GOES-East) Air Mass RGB images (above) showed the signature of a Potential Vorticity (PV) Anomaly — denoted by shades of red to pink within the comma head portion of the storm — which likely aided in enhancing precipitation rates within a midlatitde cyclone (surface analyses) as it moved across the region on 03 January 2022. RAP40 model contours of PV1.5 pressure indicated that the “dynamic tropopause” descended as low as the 900 hPa pressure level.

GOES-16 “Red” Visible (0.64 µm) images with plots of hourly surface weather type (below) showed the distribution of precipitation from 1400-2120 UTC (9:00 am – 4:20 pm EDT). Overlapping 1-minute Mesoscale Domain Sectors provided imagery at 30-second intervals during this time period. Note the development of convective banding where heavier precipitation was being reported — this storm was responsible for producing flooding rainfall and significant snowfall.

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

 ===== 04 January Update =====

GOES-16 “Red” Visible (0.64 µm) and Day Snow-Fog RGB images [click to play animated GIF | MP4]

On the following day, GOES-16 Visible and Day Snow-Fog RGB images (above) displayed the areal coverage of resulting swath of snow cover (shades of red in the RGB imagery), which stretched from northern Alabama and Georgia to southern New Jersey. A few patches of low stratiform clouds (shades of white in the RGB images) persisted in parts of the southern Appalachians during the day.

A closer look at GOES-16 Visible and Day Snow-Fog RGB images (below) is centered on Virginia — and showed the portion of Interstate 95 in northern Virginia (between Fredricksburg KEZR and Washington KDCA) where hundreds of vehicles became stranded for as long as 24 hours. Snow depths were generally in the 8-12 inch range across that area.  

GOES-16 “Red” Visible (0.64 µm) and Day Snow-Fog RGB images [click to play animated GIF | MP4]

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Tehuano wind event

A sequence of ASCAT winds (source) from overpasses of Metop-B and Metop-C at 0314, 0407, 1548 and 1607 UTC on 03 January 2022 (above) showed the early emergence of Tehuano gap winds into the Gulf of Tehuantepec, followed by their spread south-southwestward across the Pacific Ocean.GOES-16 Shortwave Infrared (3.9 µm)... Read More

ASCAT winds from Metop-B and Metop-C [click to enlarge]

A sequence of ASCAT winds (source) from overpasses of Metop-B and Metop-C at 0314, 0407, 1548 and 1607 UTC on 03 January 2022 (above) showed the early emergence of Tehuano gap winds into the Gulf of Tehuantepec, followed by their spread south-southwestward across the Pacific Ocean.

GOES-16 Shortwave Infrared (3.9 µm) images (below) revealed a cooling trend within the Gulf of Tehuantepec during the 0500-2100 UTC period — with water surface 3.9 µm brightness temperatures dropping from around 24ºC (orange enhancement) to 18ºC and below (yellow enhancement) — as the strong gap wind flow induced upwelling of colder water.

GOES-16 Shortwave Infrared (3.9 µm) images [click to play animated GIF | MP4]

The offshore transport of airborne dust was evident in GOES-17 True Color RGB images created using Geo2Grid (below).

GOES-17 True Color RGB images [click to play animated GIF | MP4]

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