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Winter storm brings snowfall to the Southeast and Mid-Atlantic states

By Scott Bachmeier •

3 days of Water Vapor imagery from GOES-19 (GOES-East) that included hourly plots of surface weather type (above) showed the development of a winter storm that produced up to 19.5″ of snowfall and wind gusts as high as 64 mph in eastern North Carolina (storm summary) — and even some light snow... Read More

GOES-19 Mid-level Water Vapor images with hourly surface weather type plotted in red (R=rain, S=snow, ZR=freezing rain, L=drizzle, F=fog), from 0601 UTC on 30 January to 1801 UTC on 01 February [click to play MP4 animation]

3 days of Water Vapor imagery from GOES-19 (GOES-East) that included hourly plots of surface weather type (above) showed the development of a winter storm that produced up to 19.5″ of snowfall and wind gusts as high as 64 mph in eastern North Carolina (storm summary) — and even some light snow in far northern Florida — from 30 January to 01 February 2026.

GOES-19 True Color RGB images from the CSPP GeoSphere site (below) showed that some of the fresh snow cover across Georgia, South Carolina and North Carolina began to melt during the day on 01 February.

GOES-19 True Color RGB images, from 1301-2156 UTC on 01 February [click to play MP4 animation]

As the low pressure system moved off the US East Coast and rapidly intensified to Hurricane Force, hazy areas seen in GOES-19 True Color RGB images (below) represented enhanced solar reflection off of high waves and sea spray where surface winds were strongest (to the east and southeast of the low center, behind its cold front).

GOES-19 True Color RGB images, from 1201-2056 UTC on 01 February [click to play MP4 animation]

GOES-19 Visible images with plots of Derived Motion Winds (DMW) (below) depicted a large swath of DMW speeds >50 kts (yellow) east and southeast of the Hurricane Force low center. GLM Flash Extent Density also showed that lightning activity was associated with areas of convection near and northeast of the low center.

GOES-19 Visible images with an overlay of Derived Motion Wind barbs and GLM Flash Extent Density, from 1246-2101 UTC on 01 February [click to play MP4 animation]

DMW speeds were as high as 82 kts (below) in the region of the hazy signature east of the low center.

GOES-19 Visible image at 1801 UTC on 01 February, with an overlay of GLM Flash Extent Density and a cursor sample of Derived Motion Winds east of the low pressure center [click to enlarge]

GOES-19 Visible image at 2001 UTC on 01 February, with an overlay of GLM Flash Extent Density and a cursor sample of Derived Motion Winds east of the low pressure center [click to enlarge]

Altimeter significant wave height values east of the Hurricane Force low were 46.13 ft derived from SWOT at 2130 UTC and 50.47 ft derived from AltiKa at 2239 UTC (below).

Significant wave height values derived from SWOT and AltiKa

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Mesolows in Lake Superior

By Scott Bachmeier •

5-minute CONUS Sector GOES-19 (GOES-East) Visible images (above) showed the development of at least 2 mesolow circulations in southern Lake Superior (off the coast of Upper Michigan) on 29 January 2026. The combination of Fixed Buoy and METAR surface reports implied that there was convergence over the portion of the lake... Read More

5-minute GOES-19 Visible images, from 1346-2201 UTC on 29 January [click to play MP4 animation]

5-minute CONUS Sector GOES-19 (GOES-East) Visible images (above) showed the development of at least 2 mesolow circulations in southern Lake Superior (off the coast of Upper Michigan) on 29 January 2026. The combination of Fixed Buoy and METAR surface reports implied that there was convergence over the portion of the lake where the mesolows formed. Just west of the mesolows, the peak wind gust at the Stannard Rock buoy (STDM4) was 29 kts at 2100 UTC.

Plots of Metop-B ASCAT surface scatterometer winds valid at 1445 UTC (below) confirmed the presence of mid-lake convergence in the area where the mesolows later developed.

GOES-19 Visible image at 1446 UTC on 29 January, with plots of Metop-B ASCAT winds valid at 1445 UTC [click to enlarge]

Surface scatterometer winds from Metop-B/C highlighted the mid-lake convergence — while OSCAT-3 winds showed the compact wind circulation associated with development of the first mesolow (below).

Surface scatterometer winds from Metop-B, Metop-C and OSCAT-3 on 29 January

Interestingly, GOES-19 GLM data displayed a single lightning flash near the Stannard Rock buoy at 1356 UTC (below), several hours prior to the mesolow development.

GOES-19 Visible image at 1356 UTC on 29 January, with an overlay of GLM Flash Extent Density (red pixel) [click to enlarge]

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Major January winter storm affects much of the southern and eastern US

By Scott Bachmeier •

5-minute CONUS Sector GOES-19 (GOES-East) Water Vapor images (above) included hourly plots of surface weather type (R=rain, S=snow, ZR=freezing rain, L=drizzle, F=fog) during the 4-day period (23 January – 26 January 2026) that a major winter storm impacted much of the southern and eastern US. According to the WPC storm summary, some notable storm statistics included: 23″... Read More

5-minute GOES-19 Mid-level Water Vapor (6.9 µm) imagery with hourly plots of surface weather type (red), from 0601 UTC on 23 January to 0001 UTC on 27 January [click to play animated GIF | MP4]

5-minute CONUS Sector GOES-19 (GOES-East) Water Vapor images (above) included hourly plots of surface weather type (R=rain, S=snow, ZR=freezing rain, L=drizzle, F=fog) during the 4-day period (23 January – 26 January 2026) that a major winter storm impacted much of the southern and eastern US. According to the WPC storm summary, some notable storm statistics included: 23″ of snowfall in Pennsylvania, 6.7″ of sleet accumulation in Arkansas and 1.0″ of freezing rain accretion in Louisiana, Mississippi, Alabama and South Carolina. Over 70 storm-related deaths resulted across the affected regions. (The 2025-2026 winter season’s first surface air temperatures in the -40s F within the Lower 48 states occurred north of this winter storm — in northern Minnesota — on 24 January.)

During the day on 26-27 January, as cloud cover cleared in the wake of the departing storm, areas that received significant ice accrual (from freezing rain and/or sleet) showed up as swaths of darker black in GOES-19 Near-Infrared “Snow/Ice” imagery (below) — darker black because ice is a stronger absorber of radiation than snow at the 1.61 µm wavelength. Widespread and long-duration power outages resulted from the weight of ice build-up on power lines.

5-minute GOES-19 Near-Infrared “Snow/Ice” (1.61 µm) images with/without METAR sites plotted gray, from 1401-2201 UTC on 26-27 January [click to play animated GIF | MP4]

According to a Storm Total Ice Accumulation analysis (below), the maximum ice accretion amount was 1.24″ just east of Oxford, Mississippi.

Storm Total Ice Accumulation, 23-26 January (courtesy Daniel Tripp, CIWRO) [click to enlarge]

On 26-27 January, the areas of significant ice accretion exhibited darker shades of red in GOES-19 Day Snow-Fog RGB images created using Geo2Grid (below) — snow cover appeared as brighter shades of red. The Day Snow-Fog RGB uses the 1.61 µm spectral band as its green component.

5-minute GOES-19 Day Snow Fog RGB images, from 1401-2201 UTC on 26-27 January [click to play MP4 animation | animated GIF]

The darker appearance of ice accrual (from freezing rain) was first noted on this blog using VIIRS imagery over Oklahoma.

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Tehuano gap wind event

By Scott Bachmeier •

As a strong arctic cold front moved southward across the Gulf of Mexico toward southern Mexico on 25-26 January 2026, the cold front fractured as it moved inland across Mexico’s Isthmus of Tehuantepec — the cold air was then channeled southward through Chivela Pass and emerged as a Tehuano (or... Read More

10-minute GOES-19 Near-Infrared images with plots of Metop-C ASCAT winds, surface fronts and METAR surface reports, from 1240-2300 UTC on 26 January [click to play MP4 animation]

As a strong arctic cold front moved southward across the Gulf of Mexico toward southern Mexico on 25-26 January 2026, the cold front fractured as it moved inland across Mexico’s Isthmus of Tehuantepec — the cold air was then channeled southward through Chivela Pass and emerged as a Tehuano (or “Tehuantepecer“) gap wind that eventually fanned outward across the Gulf of Tehuantepec and adjacent Pacific Ocean. 10-minute Full Disk scan GOES-19 (GOES-East) Near-Infrared images (above) showed the hazy plume of dust that was being transported offshore — along with a narrow arc cloud that marked the southern and eastern edges of this Tehuano flow.

A topography image ((below) also showed Metop-B ASCAT winds emerging from the southern coast of Mexico, after the gap winds had accelerated through Chivela Pass; wind speeds were as high as 37 kts. The Tropical Analysis and Forecast Branch had issued a polygon where Storm Force winds were likely over the Gulf of Tehuantepec.

Topography image, with Metop-B ASCAT wind barbs (having speeds of 34-47 kts) valid at 1557 UTC plotted in cyan [click to enlarge]

A toggle between Metop-B ASCAT and OSCAT-3 surface scatterometer images (below) depicted the pulse of Tehuano winds off the Pacific coast of Mexico.

Metop-B ASCAT winds at 1557 UTC and OSCAT-3 winds at 1849 UTC on 26 January

In a side-by-side comparison of Nighttime Microphysics RGB and daytime True Color RGB images from GOES-18 (GOES-West) and GOES-19 (GOES-East) sourced from the CSPP GeoSphere site (below), a large pulse of airborne dust was seen emerging from Mexico’s Pacific coast and spreading south-southwest across the Gulf of Tehuantepec.

10-minute Nighttime Microphysics RGB and daytime True Color RGB images from GOES-18 (left) and GOES-19 (right), from 0700-2300 UTC on 26 January [click to play MP4 animation]

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