Much of the state of Alaska is finds itself impacted by a strong atmospheric river on Friday, 16 January 2026. Moisture has been plunging due north from the tropics to the southern coast of Alaska. The river has brought with it precipitation and temperatures well above normal. One of the best ways to monitor the location and strength of an atmospheric river is with the CIMSS MIMIC-TPW product, which merges polar-orbiting and geostationary products to provide microwave-like observations of total precipitable water at a much greater frequency than is possible with the polar orbiter microwave instruments. A quick glance at the MIMIC-TPW product makes it easy to identify the area of anomalous moisture.

Zooming out enables us to see the plume in a global context. Here, it appears as a direct plume linking Alaska directly to the high moisture region of the tropical Pacific. Note that this also appears to be not the only atmospheric river that is impacting Alaska, with another plume in the north central Pacific. According to the GFS model, these two rivers are forecasted to merge over the weekend.

The impacts of this river on sensible weather are significant. Temperatures in southern Alaska are elevated compared to normal. The normal high temperature for Anchorage on January 16 is 22 F, but temperatures reached 39 F by midday. Reports from Anchorage note rain falling on snow-packed roads, creating slippery conditions despite the greater-than-freezing temperatures. Numerous avalanche warnings have also been issued in southern Alaska due to large areas of heavy rain and snow created by the atmospheric river.

The GOES-18 water vapor channels (in this case, channel 8, 6.2 microns) can also provide some insight into the strength of this event. Here, it is easy to see how the moist air is streaming north to the southern Alaska shore where it then starts dispersing into the interior of Alaska as well as the Yukon and Northwest Territories of Canada. This loop also shows the challenges associated with using geostationary imagery in polar regions: the significant displacement from the sub-satellite point over the equator means oblique viewing angles and very coarse pixel resolution; just compare the size of the pixels at the top of this loop to those at the bottom.

At these higher latitudes, polar orbiting satellites offer a promising alternative. The primary disadvantage of polar orbiters, the relatively coarse temporal resolution relative to geostationary satellites, is lessened near the poles as orbits are constantly overlapping. However, neither the United States’s VIIRS nor EUMETSAT’s AVHRR have water vapor sensitive channels, so while views of the clouds from visible or infrared imagery are possible, additional information about the water vapor distribution at the fine horizontal resolution of a polar orbiting satellite is not possible.

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5-minute CONUS Sector GOES-19 (GOES-East) GeoColor RGB images with an overlay of Next Generation Fire System (NGFS) Fire Detection polygons (above) displayed numerous thermal signatures and smoke plumes associated with prescribed burns near the Gulf Coast of Texas and Louisiana on 15 January 2026.

Two of the hottest-burning fires occurred near the coast in far southwest Louisiana — as seen in a closer view (below).

The hottest of these 2 fires was located along the eastern shore of Sabine Lake (below) — which exhibited a maximum 3.9 µm brightness temperature of 136ºC (which is only about 2 degrees below the 137.77ºC saturation temperature of GOES-19 Band 7 detectors) at 1836 UTC. Interestingly, even though this was the hottest-burning fire (that produced a sizable and dense smoke plume) it only burned for about 4 hours, from 1726-2121 UTC.

The second fire was located farther east, in the Rockefeller Wildlife Refuge (below) — which exhibited a maximum 3.9 µm brightness temperature of 116ºC at 2051 UTC.

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On 14 January 2026, a strong surface pressure gradient was found over the upper Midwestern United States. This can be seen in the NOAA Weather Prediction Center surface map for 1500 UTC on this day. While the center of the low pressure system is off over southern Québec, the tight packing of the isobars over the Great Lakes region indicates that low-level winds are going to be intense throughout the region.

By suing scatterometers, satellites are particularly useful at identifying surface winds over large bodies of water, so long as they’re still liquid. While it is mid-January, the main bodies of Lakes Michigan and Superior are still wide open, so scatterometer winds can help diagnose the winds over those locations. The following plot shows the ASCAT from EUMETSAT’S MetOP-C satellite.

With winds over Lake Superior from the north,the flow has a significant amount of fetch across the lake. This allows for largely uninhibited wind speeds as little is in the way to slow the winds down, allowing them to reach speeds in excess of 40 kts in places. Of course, this is resulting in a classic lake effect event as seen on the GOES-19 True Color product. The classic parallel bands of clouds are clearly visible over much of eastern Superior.

However, if you look at the contemporaneous radar, the snow appears to me much less widespread than would be expected from the satellite coverage. The snow appears to be constrained to a relatively small-radius around the Marquette, Michigan, radar. However, this is because lake effect snows are quite shallow, often less than 1.5 km deep. Since radars have a minimum elevation angle, after a certain distance away from the radar, the beam is overshooting the altitudes where the snow is forming.

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A combination of 10-minute Full Disk scan and 5-minute PACUS Sector GOES-18 (GOES-West) False Color RGB images from the NOAA/CIMSS Volcanic Cloud Monitoring site (above) showed the signature of a volcanic cloud following the eruption of Kilauea on the Big Island of Hawai`i — which became apparent after 1831 UTC on 12 January 2026, and soon thereafter began moving south-southeast. (This was Episode 40 of the ongoing Kilauea eruption; Episode 1 began on 23 December 2024.) Since this False Color RGB product uses the ABI 8.5 µm spectral band (which is sensitive to SO₂ absorption) in its green component, shades of cyan were indicative of a high concentration of SO₂ within the volcanic cloud.

A plot of rawinsonde data from Hilo (below) indicated that NW winds were present between the altitudes of 2.2-4.4 km (the summit of Kilauea is at an elevation of 1.25 km), which were responsible for the south-southeast transport the volcanic cloud. According to the Hawaiian Volcano Observatory, the volcanic plume rose to altitudes of 4 km over the eruption site, before moving southeast at higher altitudes.

GOES-18 True Color RGB images from the CSPP GeoSphere site (below) provided a view of the volcanic cloud that initially developed at 1816 UTC and later moved south-southeast of the Big Island. In addition, an overshooting top was frequently seen directly over the eruption site. A larger-scale animation that extends to sunset is available here.

GOES-18 Shortwave Infrared images (below) displayed the thermal signature of lava fountaining and lava flows during Kilauea’s eruption (which was briefly masked by clouds at times).

As early as 1836 UTC on 12 January (14 minutes after eruption onset), the thermal signature exhibited a 3.9 µm brightness temperature of 137.88ºC (below) — which is the saturation temperature of GOES-18 ABI Band 7 detectors. This saturation temperature was intermittently seen until the eruption episode ended at 0404 UTC on 13 January.

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