5-minute CONUS Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images (above) displayed areas of convection that moved inland along the west coast of Florida on 11 June 2024. Sarasota/Bradenton International Airport received very heavy rainfall (3.93 inches) during the 1-hour period ending at 2353 UTC or 7:53 PM local time (METARs | decoded surface reports | plot of surface report data) — which was a new record maximum 1-hour rainfall accumulation for that location (contributing to their record daily rainfall of 6.26 inches).

A GOES-16 Infrared image showing a cold thunderstorm overshooting top at 2311 UTC (below) included a cursor sample of the associated GOES-16 Rain Rate derived product — which was 3.17 in/hr, compared to the 3.93 in observed at Sarasota/Bradenton for the hour ending at 2353 UTC. Note that the cold overshooting top and high rain rate were displaced about 6 mi northwest of KSRQ — for a Cloud Top Height around 50 kft, this is consistent with the parallax adjustment of ~10 km with GOES-East imagery over Florida.

GOES-16 Infrared images with an overlay of GLM Flash Extent Density (below) showed the lightning activity associated with these thunderstorms, which included a few brief lightning jumps (most notably near Bradenton at 2316 UTC, 5 minutes after the peak GOES-16 Rain Rate).

5-minute GOES-16 Visible images (below) also depicted many of the thunderstorm overshooting tops — but also showed the offshore cyclonic circulation of low-level clouds associated with Tropical Invest 90L (what role 90L may have played in helping to force the development of the heavy-rainfall-producing thunderstorms is not known).

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) showed thunderstorms that produced hail as large as 1.75 inch in South Dakota along with wind gusts as high as 75 mph in Wyoming and Nebraska, and 74 mph in South Dakota (SPC Storm Reports | KUNR Local Storm Reports) on 10 June 2024. The Infrared images revealed thunderstorm overshooting tops that exhibited infrared brightness temperatures as cold as -65ºC (darker shades of red) — according to a plot of rawinsonde data from Rapid City, South Dakota at 1900 UTC on 10 June (below) that temperature represented a slight overshoot of the Most Unstable (MU) air parcel Equilibrium Level (EL).

5-minute GOES-16 Visible images combined with the Total Precpitable Water (TPW) derived product (above) and the Lifted Index (LI) and CAPE derived stability indices (below) indicated that these thunderstorms developed along or just ahead of an advancing cold front — and a corridor of modest moisture (TPW values to 1.5 in) and minor instability (LI values to -4ºC and CAPE values to 850 J/kg) was in place ahead of this cold front.

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This blog post shows satellite imagery with a Singapore Airlines Boeing 777-300ER that encountered severe turbulence while flying over southern Myanmar (information from flightradar) at 0749 UTC on 21 May 2024. This graphic from Sarah Griffin, CIMSS, shows the turbulence location/time; other graphics/animations from this event are in this directory that Sarah Griffin created.

LightningCast probabilities predict where an (in this case, hypothetical) GLM instrument would detect a lightning flash in the next 60 minutes based on current ABI or AHI imagery at 0.64 µm, 1.61 µm, 10.3 µm and 12.3 µm. Although this machine-learning tool was trained on GOES-East ABI and GLM imagery, it is being applied to the similar AHI instrument that flies on Himawari-9. (Real-time Himawari-9 LightningCast imagery is available at this RealEarth instance under the ‘Guam’ sector). The LightningCast contours shown in this blog post were created using a CSPP Geo software package in development/testing at CIMSS, with a Beta release on the horizon. More than an hour before the turbulence that affected the Boeing 777, LightningCast is suggesting the region is very likely to have lightning. The animation below shows how the LightningCast contours (and satellite imagery) changed between 0630 and 0800 UTC on 21 May. Diagnosed probabilities of lightning remain high over the region throughout the 80-90 minutes prior to the turbulent encounter.

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1-minute Mesoscale Domain Sector GOES-18 (GOES-West) “Red” Visible (0.64 µm) images (above) showed areas of bright sun glint off the open (ice-free) water in the Chukchi Sea — just off the coast of Alaska, from the Bering Strait to near Utqiagvik (formerly Barrow) — around 1 AM local time on 08 June 2024. Note how there was also sun glint off the open water of leads within the sea ice, as well as inland rivers/lakes across northern Alaska.

Synthetic Aperture Radar (SAR) wind speed (source) derived from an overpass of RADARSAT-2 at 0349 UTC on 08 June (below) showed that winds were generally light (or even calm) across the nearshore waters off the northwest coast of Alaska — which would be conducive to a sea surface with minimal wave height (that would more easily reflect incoming late-day sunlight arriving at a very oblique angle, enhancing sun glint).

ASCAT and OSCAT surface scatterometer winds (source) confirmed the presence of light wind speeds over a portion of the open water north of the Bering Strait, where the sun glint was seen (below).

During the subsequent daytime hours, a sequence of VIIRS Snowmelt RGB images sourced from GINA and displayed using RealEarth (below) provided a more detailed view of the sea ice and the areas of inland snow cover (shades of cyan to light blue), in contrast to the areas of open water (dark blue) near the Alaskan coast.

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