Bomb cyclone makes landfall along the Oregon/California coast

November 26th, 2019 |

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images, with 3-hourly plots of surface fronts [click to play animation | MP4]

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images, with surface fronts plotted in cyan and buoy locations plotted in red [click to play animation | MP4]

A sequence of GOES-17 (GOES-West) Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (above) showed the evolution of a bomb cyclone (surface analyses: WPC | OPC) that made landfall along the Oregon/California coast just after sunset on 26 November 2019. The storm produced wind gusts of 106 mph in southwestern Oregon and 70 mph in northwestern California.

GOES-17 “Red” Visible (0.64 µm) images of the storm are shown below — the Mean Sea Level Pressure anomaly was 4-5 sigma below the climatological mean as the rapidly-deepening midlatitude cyclone made landfall. Similarly, 925 hPa wind speed anomaly was 3-5 sigma above the climatological mean. The system had transitioned to a warm seclusion phase by 00 UTC, as seen in a comparison of Visible and Water Vapor images at that time.

GOES-17 "Red" Visible (0.64 µm) images, with 3-hourly plots of surface fronts [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) images, with surface fronts plotted in cyan and buoy locations plotted in red [click to play animation | MP4]

A GOES-17 Mesoscale Domain Sector was positioned over the region, providing Visible images at 1-minute intervals (below).

GOES-17

GOES-17 “Red” Visible (0.64 µm) images, with hourly plots of surface wind barbs and gusts in knots [click to play animation | MP4]

A larger-scale view of the entire GOES-17 Mesoscale Domain Sector is shown below, using Visible images from the AOS site.

GOES-17 "Red" Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) images [click to play animation | MP4]

1-km resolution NOAA-15 AVHRR Shortwave Infrared (3.7 µm) imagery at 0217 UTC (below) showed the center of circulation just off the Oregon/California coast. At that time, winds were gusting to 50 knots at Crescent City, California (KCEC).

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image at 0217 UTC [click to enlarge]

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image at 0217 UTC, with plots of 02 UTC surface reports (cyan/yellow) and wind gusts (in knots, red) [click to enlarge]

A time series of surface data from Crescent City, California (below) showed the period when the air pressure dropped to 973.4 hPa (28.74 inches) — setting a new all-time low pressure record for the state of California. In addition, new low pressure records for the month of November were set at Medford, Oregon (981.4 hPa / 28.98 inches) and at Eureka, California (984.8 hPa / 29.08 inches).

Time series of surface data at Crescent City, California [click to enlarge]

Time series of surface data at Crescent City, California [click to enlarge]

Air pressure at the offshore buoy 8 miles NW of Crescent City (46027) dropped to 971.7 hPa (28.69 inches) at 0350 UTC (below).

Plots of Wind Speed (blue), Wind Gust (red) and Air Pressure (green) from Buoy 46027

Plots of Wind Speed (blue), Wind Gust (red) and Air Pressure (green) from Buoy 46027


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