Monday, 13 January 2025
Hall C (New Orleans Ernest N. Morial Convention Center)
Handout (1.1 MB)
On 27 June, 2024, the Weather Forecast Office (WFO) in Fairbanks issued the National Weather
Services’ furthest northwest Severe Thunderstorm Warning to date. The warning was issued at
67.6°N, 163.0°W where no radar coverage exists, surface observations are sparse, and
substantial satellite parallax complicates convective warning decision making. This work
presents model data leading up to the event, synoptic and mesoscale parameters during the
event, and available observational data. Preliminary analysis found two periods of intense
lightning activity (>400 strokes per hour) punctuated by passage across a cold body of water -
Selawik Lake - when lightning activity paused. Infrared cloud top temperatures of overshooting
tops cooled to as low as -52.69°C on the Suomi-NPP satellite (Bachmeier 2024) coinciding with
periods of intense lightning activity. Severe wind gusts and hail stones were not reported, but
webcam imagery in Noatak showed a well-defined shelf cloud and the closest automated
observation site in Kotzebue ~56 km away recorded a 34-knot wind gust. Collective results
indicate an unusual convective environment that may highlight severe thunderstorms as an
emerging forecasting challenge within a rapidly warming Arctic climate.
Services’ furthest northwest Severe Thunderstorm Warning to date. The warning was issued at
67.6°N, 163.0°W where no radar coverage exists, surface observations are sparse, and
substantial satellite parallax complicates convective warning decision making. This work
presents model data leading up to the event, synoptic and mesoscale parameters during the
event, and available observational data. Preliminary analysis found two periods of intense
lightning activity (>400 strokes per hour) punctuated by passage across a cold body of water -
Selawik Lake - when lightning activity paused. Infrared cloud top temperatures of overshooting
tops cooled to as low as -52.69°C on the Suomi-NPP satellite (Bachmeier 2024) coinciding with
periods of intense lightning activity. Severe wind gusts and hail stones were not reported, but
webcam imagery in Noatak showed a well-defined shelf cloud and the closest automated
observation site in Kotzebue ~56 km away recorded a 34-knot wind gust. Collective results
indicate an unusual convective environment that may highlight severe thunderstorms as an
emerging forecasting challenge within a rapidly warming Arctic climate.
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