This website works best with a newer web browser such as Chrome, Firefox, Safari or Microsoft Edge. Internet Explorer is not supported by this website.

CIMSS Satellite Blog

MENU

Strong winds causing heavy freezing spray off the Alaska coast

By Scott Bachmeier •

GOES-18 “Red” Visible (0.64 µm) images, with and without plots of Derived Motion Winds [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-18 (GOES-West) “Red” Visible (0.64 µm) images (above) include plots of Derived Motion Winds (DMW) — and showed the rapid offshore transport of cold arctic air across the southern Cook Inlet, Shelikof Strait and northwestern Gulf of Alaska on 12 February 2023. The fastest low-level (Surface – 900 hPa) DMW speed was 64 knots in the far southern portion of Cook Inlet at 2305 UTC (below).

GOES-18 “Red” Visible (0.64 µm) image at 2305 UTC, with plots of Derived Motion Winds (DWM) and a cursor readout showing a 64-knot DMW wind speed [click to enlarge]


Heavy Freezing Spray Warning issued for the Shelikof Strait [click to enlarge]

A Heavy Freezing Spray Warning had been issued for that entire offshore region (light blue), including the Shelikof Strait (above) — and Buoy 46077 in the Shelikof Strait was recording Ice Accretion rates in excess of 1.0 inches per hour (below). Buoy air temperatures had fallen into the 10-12F range during that time, with wind gusts of 40-50 knots — providing ideal conditions for rapid ice accretion.

Plot of Buoy 46077 Ice Accretion Rates

RCM/Radarsat-2 SAR winds at 1630 UTC on 12 February (source) are shown below — a NW-to-SE oriented swath of strong offshore winds (40-50 knots, darker shades of red) was seen extending from the far southern end of Cook Inlet (where the aforementioned 64-knot GOES-18 DMW speed was located) into the northwestern Gulf of Alaska. Another pocket of similarly-strong wind speeds was evident farther to the north, in the vicinity of Homer, Homer Spit and the mouth of Kachemak Bay.

RCM/Radarsat-2 SAR winds at 1630 UTC on 12 February [click to enlarge]

Categories: GOES-18, Marine weather, SAR, Satellite winds, Winter weather