Rapidly intensifying storm in the North Pacific Ocean
GOES-17 (GOES-West) Mid-level Water Vapor (6.9 µm) and Air Mass RGB images (above) depicted a rapidly intensifying Storm Force low (surface analyses) moving from the North Pacific Ocean toward the Alaska Panhandle on 04 March 2020. A comparison of GOES-17 Mid-level Water Vapor and Air Mass RGB images with NAM40 PV1.5 pressure (below) showed that the Dynamic Tropopause — taken to be the pressure of the Potential Vorticity 1.5 surface — had descended to the 650 hPa pressure level in the vicinity of the low at 1200 UTC. The deeper red hues on Air Mass RGB imagery also indicated the presence of ozone-rich stratospheric air within the atmospheric column as the tropopause lowered in the vicinity of the rapidly-deepening low pressure. 1-minute Mesoscale Domain Sector GOES-17 “Red” Visible (0.64 µm) images (below) revealed mesovortices within the core of the large low pressure system.===== 05 March Update =====
On the following day, GOES-17 “Clean” Infrared Window (10.35 µm) mages (above) showed clouds associated with the Storm Force low as it moved slowly northward near the coast of the Alaska Panhandle (surface analyses). The storm prompted a wide variety of advisories, including a High Wind Warning for the Juneau area and a Blizzard Warning for the Skagway area.Strong arctic outflow event ongoing across the N Panhandle. Gale and storm force winds + freezing spray in many of the northern marine areas. Blizzard warning for Klondike Highway, and High wind warning for downtown Juneau and Douglas. #akwx pic.twitter.com/rEPlhPeKBc
— NWS Juneau (@NWSJuneau) March 5, 2020
GOES-17 True Color Red-Green-Blue (RGB) images created using Geo2Grid (below) revealed several plumes of airborne glacial silt drifting over the Gulf of Alaska, lofted by a strong offshore gap winds. A ship near Prince William Sound reported blowing dust at 18 UTC. Also seen in the images was the northwestward drift of ice into Cook Inlet and Turnagain Arm as high tide approached.