Atmospheric river moves across the North Pole
MIMIC Total Precipitable Water product during the period 0400 UTC on 06 March to 1200 UTC on 08 March 2023 [click to play animated GIF | MP4]
The MIMIC Total Precipitable Water product during the period 0400 UTC on 06 March to 1200 UTC on 08 March 2023 (above) displayed the poleward transport of an atmospheric river (AR) that moved across Alaska and then the North Pole — eventually passing over Svalbard (located between Norway and Greenland). As this AR was emerging from the north coast of Alaska and approaching the North Pole, Total Precipitable Water (TPW) value anomalies were as high as 5-6 standard deviations above normal (source).
As the AR moisture plume was moving over Utqiagvik (formerly “Barrow”; station identifier PABR) Alaska at 0000 UTC on 07 March, the rawinsonde-derived TPW value was 0.62 inch (which might have been a monthly record high TPW for PABR, according to this tweet). At that particular time there was good agreement with the MIMIC TPW product, whose value in the vicinity of PABR was 0.65 inch (below).
MIMIC Total Precipitable Water product at 0000 UTC on 07 March, along with a cursor sample showing the PABR surface report at that time [click to enlarge]
The NESDIS Snowfall Rate product from the CICS site (below) showed the AR plume of clouds that was likely producing snowfall at the surface as it moved northward from the coast of Alaska to the Arctic Ocean.
NESDIS Snowfall Rate product [click to play animated GIF]
As the AR was passing across the North Pole, the maximum MIMIC TPW value at that location was 0.25 inch at 0900 UTC on 07 March (below).
MIMIC TPW value over the North Pole at 0900 UTC on 07 March [click to enlarge]
As the leading edge of the AR eventually began moving over Svalbard (station identifier ENSB) — a distance of approximately 2000 miles from the northern coast of Alaska — light snow was observed at 2000 UTC (below) and 2100 UTC on 07 March, and then again at 0900-1000 UTC on 08 March.
MIMIC TPW product at 2000 UTC on 07 March, with a cursor sample of the METAR surface observation at Svalbard ENSB [click to enlarge]
Note the gradual increase in temperature and dew point as the AR continued to traverse Svalbard (below).
Time-series plot of surface report data from Svalbard Lufthaven [click to enlarge]