Morning radar on the morning of 19 January 2024 (shown below from this source) showed a single band of snow squalls moving southward over central Lake Michigan. Then band moved inland over northwestern Indiana, resulting in a winter storm warning over northwestern Indiana (More information from NWS IWX) and hazardous travel conditions through that heavily-traveled corridor between Chicago and Detroit. GOES-16 Clean Window Infrared (Band 13, 10.3 µm) imagery, below, shows a subtle lake-effect band signature emerging as the clouds associated with a system that deposited widespread light snow over the upper Midwest exits to the east. Surface observations, especially of CMAN sites, show convergence over the lake. Note the east/northeast winds at stations LDTM4 (Ludington MI) and BSBM4 (Big Sable Point MI) over central lower Michigan and the northwest winds along Lake Michigan’s western shore. Sometimes lake effect bands are vigorous enough to produce convection. That was not the case for this band; GLM detected no flash events (in addition, LightningCast probabilities were less than 2%!)

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Merged Snowfall rates (source; a field that combines observations from radars and from polar orbiting satellites’ microwave observations of the atmosphere), below, show that the single band started to coalesce shortly after 0700 UTC. Microwave observations over the Great Lakes did not occur at the hourly intervals shown (although some observations are present over the Pacific Northwest, where the gap-filling between radars is more important!); however, there were microwave estimates of snowfall rate at 0850 and 0920 UTC, as shown in this toggle. Light snow in Madison WI was just ending at 0900 UTC/3 AM CST; compare the 0900 mSFR field (radar-only coverage over the midwest) and the 0850 UTC/0920 UTC mSFR fields (here are all 3 in an animation): satellite-based microwave estimates of snow better capture the back edge of the light snow than the radar-only image.

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The single band is increasingly apparent in the animations below of Day Cloud Phase Distinction and Day Cloud Type RGBs. Because the airmass is very cold, the Day Cloud Phase Distinction RGB (that has as its red component the 10.3 brightness temperature) shows low-level snow-cover as much redder than in the Day Cloud Type RGB that has as it red component the 1.38 reflectance. (There is sufficient water vapor in the atmosphere that a surface reflectance signal is absorbed). Both RGBs show the mid-lake convective band as a series of discrete convective towers forming a sinuous band as it approaches the southern Lake Michigan shoreline. Shortly the end of the animation one of the towers over north central Lake Michigan is vigorous enough that LightningCast probabilities have reached 10% (click here to see the Day Cloud Type RGB at 1601 UTC) .

A bit more zoomed in Cloud Phase Distinction RGB, as well as ABI “red” visible band 2 (still and movie). These images were made with the geo2grid software.

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MetopC overflew the western Great Lakes shortly before 0200 UTC on 19 January 2024. Advanced Scatterometer (ASCAT) imagery from that time (source) show northeasterly winds, suggesting mid-lake convergence, along the southeast edge of the swath.

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Overlapping 1-minute Mesoscale Domain Sectors provided GOES-16 (GOES-East) images at 30-second intervals from all 16 of the ABI spectral bands in addition to a Rocket Plume RGB (above), which displayed the northeast-moving warm thermal signature of a SpaceX Falcon 9 stage 1 rocket booster as the Ax-3 Mission was launched from NASA Kennedy Space Center in Florida at 2149 UTC (4:49 PM EST) on 18 January 2024. Due to the presence of widespread lower-tropospheric and upper-tropospheric clouds off the coast — note the moist layers seen in a plot of morning Cape Canaveral rawinsonde data (the high-altitude clouds were due to a subtropical jet stream over the Southeast US) — the rocket’s thermal signature was apparent in a more limited subset of Near-Infrared (ABI spectral bands 04/05/06) and Infrared (ABI spectral bands 07/08/09/10) images compared to many previous rocket launches.

One noteworthy feature seen in GOES-16 Water Vapor and Rocket Plume RGB imagery was the subtle trail of hot water vapor in the wake of the departing Falcon 9 stage 1 rocket booster, which could be seen drifting to the north-northwest in 30-second images from 2152-2153 UTC (below).

A comparison of GOES-16 Rocket Plume RGB, Upper-level Water Vapor, Mid-level Water Vapor and Shortwave Infrared images at 21:55:25 UTC (below) revealed a warm thermal signature of the Falcon 9 stage 1 entry burn — which slowed the rocket’s rate of descent as it re-entered the Earth’s atmosphere — to prepare it for a landing at Cape Canaveral Space Force Station.

GOES-16 Visible images (below) showed the brighter white Falcon 9 rocket condensation cloud as it emerged from the low-level cloudiness, and was subsequently sheared eastward by westerly winds of 40-70 kts.

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GOES-18 (GOES-West) and GOES-16 (GOES-East) True Color RGB images from the CSPP GeoSphere site (above) showed hazy arcs of blowing dust lofted by Tehuano gap winds that emerged from the south coast of Mexico — which spread out across the Gulf of Tehuantepec and the adjacent waters of the Pacific Ocean on 16-17 January 2024.

GOES-16 Visible images on 16 January (below) included surface plots, Metop ASCAT winds and surface analyses. The development of Gale Force winds was being forecast for the Gulf of Tehuantepec, as northerly winds behind an approaching arctic cold front accelerated through the Chivelas Pass (topography) before exiting the southern coast of Mexico near Ixtepec (MMIT).

As the strong arctic cold front moved inland across the northern coast of Mexico, a notable drop in temperature and dew point was seen at Veracruz (MMVR) and Minatitlan (MMMT), with northerly winds gusting to 45 knots at Veracruz (below).

Surface winds derived from Metop-B/Metop-C ASCAT and GCOM-W1 AMSR2 (source) showed the intensification of Tehuano gap wind flow (below) — the presence of Gale Force winds (34-47 knots) in the Gulf of Tehuantepec was confirmed by both ASCAT and AMSR2.

Significant Wave Height values up to 11.66 ft were generated by these Gale Force winds, according to CryoSat-2 altimetry data (below).

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LightningCast probability fields are routinely produced at CIMSS and incorporated into a RealEarth display (LightningCast probability fields are also available in some National Weather Service AWIPS machines). An example of LightningCast is shown below over Southern Florida. Contours show the probability of a GLM observation of lightning within the next 60 minutes: 10% (Blue), 20% (Cyan), 50% (Green), 75% (Magenta).

Scientists/Programmers at CIMSS are working on a CSPP Geo package that will create LightningCast probability fields, both current and historical. The software has the ability to subsect data, so full-disk (or full-CONUS for GOES-16 or full-PACUS for GOES-18) imagery need not be created. An example of the output for the same times and location as the RealEarth display is shown below.

The animation below stacks both the CSPPGeo and RealEarth output. There are minor differences that are being investigated.

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If you are at the AMS 2024 Meeting in Baltimore at the end of January, you can learn more about LighningCast at this talk on Thursday, 4:45-5 PM, in room 336. A LightningCast Probability QuickGuide is available here.

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