Tropical Storm Hilary makes landfall in Baja California
GOES-18 Mid-level Water Vapor (6.9 µm) images, with an overlay of Surface Pressure analyses (beige) and 1-hour Precipitation Accumulation (red) [click to play animated GIF | MP4]
GOES-18 (GOES-West) Mid-level Water Vapor (6.9 µm) images (above) included plots of 1-hour Precipitation Accumulation — which showed rainfall associated with the northward spread of moisture across the Southwest US as Tropical Storm Hilary made landfall in Baja California on 20 August 2023. A similar animation with plots of 6-hour Precipitation Accumulation is available here. There were numerous daily rainfall records set, with widespread reports of flash flooding across parts of southern California and southern Nevada.
Hourly images of the MIMIC-TPW product (below) also showed the northward transport of abundant tropical moisture ahead of Hilary.
Hourly MIMIC-TPW product [click to play animated GIF | MP4]
New record maximum Total Precipitable Water (TPW) values were established for 1200 UTC soundings on 20 August at both San Diego, California and Las Vegas, Nevada (below).
Climatology of 1200 UTC sounding Total Precipitable Water (TPW) for San Diego, California– with the TPW value for 20 August 2023 indicated by a gray circle [click to enlarge]
Climatology of 1200 UTC sounding Total Precipitable Water (TPW) for Las Vegas, Nevada — with the TPW value for 20 August 2023 indicated by a gray circle [click to enlarge]
In addition, the all-time record maximum 0000 UTC sounding Total Precipitable Water (TPW) value of 2.38 inches was tied at San Diego, California (below).
Climatology of 0000 UTC sounding Total Precipitable Water (TPW) for San Diego, California– with the TPW value for 21 August 2023 indicated by a gray circle [click to enlarge]