Strong northerly winds created blowing snow and blizzard conditions across parts of eastern North Dakota and western Minnesota — particularly within the Red River Valley — on 17 January 2026. 5-minute CONUS Sector GOES-19 (GOES-East) Near-Infrared “Snow/Ice” images (above) showed the development of Horizontal Convective Rolls (HCRs) where winds were channeled down the Red River Valley, with gusts in excess of 30 knots (reducing the surface visibility to less than 1 mile) at several METAR sites.

GOES-19 Blowing Snow RGB images created using Geo2Grid (below) provided a more distinct view of the HCRs.

===== 18 January Update =====

Even stronger winds in the wake of a cold frontal passage (with gusts in excess of 40 knots) produced a second day of blowing snow and blizzard conditions across eastern North Dakota and western Minnesota on 18 January — and HCRs were once again very prevalent in GOES-19 Blowing Snow RGB images (above), across a larger area than the previous day. The surface visibility was reduced to near zero at some METAR sites.

View only this post Read Less

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.

View only this post Read Less

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.

View only this post Read Less

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.

View only this post Read Less