1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Day Cloud Type RGB images (above) displayed narrow bands of mixed phase to glaciated (brighter shades of green to yellow) clouds that produced snow squalls as they moved eastward across western and central Pennsylvania in the wake of a cold frontal passage on 10 March 2024. Periodic lightning activity — denoted by blue GLM Flash Extent Density pixels — was seen with some of these snow squall bands. These snow squalls briefly reduced the surface visibility to 1/4 mile at some sites.

The GOES-16 Day Cloud Type RGB image at 1519 UTC — with/without an overlay of GLM FlashExtent Density — included cursor displays of the corresponding Cloud Top Phase, Cloud Top Temperature and Cloud Top Height derived products near the center of one of the cloud bands (below).

The Pittsburgh and State College NWS forecast offices issued numerous Snow Squall Warnings for these features.

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Every Spring and Fall Equinox season, a brief period of solar Radio Frequency Interference (RFI) occurs whenever the Sun passes into the beam of a GOES ground station receiving antenna (2023 NOAA ESPC Notification). This RFI can cause a temporary degradation or even a complete loss of data reception. The exact time of RFI will vary somewhat on a given day, depending on where the GOES receiving antenna is located.

During the Spring of 2024, Full Disk images showed that the time of maximum RFI signal loss was 1700 UTC on 01-05 March for GOES-16 (GOES-East) (above), and 2140 UTC on 02-05 March for GOES-18 (GOES-West) (below).

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Parts of the Hawaiian Islands have been placed under Flood Warnings on 4 March 2024 (Link). Part of the reason for these heavy rains is unusually cold air aloft, at 500 mb. The animation above (from the CSPP Geosphere site — a direct link to the animation is here) shows a characteristic color change in the Night Microphysics around the Hawai’ian islands as convective showers develop, from light pinks/whites to red. How cold are the temperatures at 500 mb that are helping support this convection?

Soundings at Lihue at 0000 UTC on 2 March and 1200 UTC 4 March (above, from the University of Wyoming sounding site) show consistenly cold temperatures, at -14.7^oC, although temperatures were warmer on 3 March, closer to -11^oC. The 500-mb temperatures on 4 March at 1200 UTC were colder than all but <10% of the observations per the analysis below from the SPC Sounding analysis site.

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NOAA-20 NUCAPS profiles give twice-daily estimates of thermodynamic variables over the Hawai’ian islands. These profiles are an important data source over ocean regions where conventional data are otherwise rare. The analyses near 0000 and 1200 UTC on 4 March 2024, below, show the large extent of cold temperatures at 500 mb, with temperatures between -14 and -16^oC just north of Kauai. Temperatures are warmer over the big Island of Hawai’i. Use NUCAPS profiles to monitor cold temperatures at 500 mb when unusual cold is ongoing.

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The gridded NUCAPS fields above are from AWIPS. You can also access them at this RealEarth site, and at this site maintained by SPoRT. The animation below of imagery from the SPoRT site shows values from 1200 UTC 2 March through 1200 UTC 4 March. Colder air overspread the western Hawaiian islands on the 4th.

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5-minute CONUS Sector GOES-16 (GOES-East) Shortwave Infrared (3.9 µm), Near-Infrared “Snow/Ice” (1.61 µm), Fire Mask (a component of the GOES Fire Detection and Characterization Algorithm FDCA) and Near-Infrared “Cloud Particle Size” (2.24 µm) images (above) displayed the thermal signatures associated with a storage facility fire — which was responsible for 1 fatality and 1 injury (media report) — near Detroit shortly after sunset on 04 March 2024. The highest 3.9 µm infrared brightness temperature was 33.11ºC at 0201 UTC.

With a thin layer of mid-level clouds moving across the region, the fire signature was somewhat attenuated — so the AWIPS Color Table Ranges were adjusted to better highlight the feature: 3.9 µm image max/min values were set to 40/-30, with the 1.61 µm and 2.24 µm image max/min values set to 50/0.

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