Thursday, May 12, 2022

April Climate Data

I'm a few days behind on this, but for future reference - here are the NOAA climate division rankings for April in Alaska, expressed in terms of the percentile of each variable within the historical distribution of the prior 30 years.


It was significantly colder than normal in the southeastern interior and southeast Alaska; for example, Northway saw its 3rd coldest April in the past 30 years (coldest since 2013), but April in Fairbanks ended up not being as cold as last year.  Precipitation was very scarce - not an unusual occurrence, given that it's the driest month of the year statewide on average - but this was unusual, with the 4th lowest statewide April precipitation total on record (back to 1925).

Here's Rick Thoman's temperature plot:


At first glance this suggests that western Alaska had more unusual warmth than indicated by the NOAA data, but note that most of the climate sites with +3-5°F temperature anomalies are right on the Bering Sea coast, where sea ice quickly broke up in April.  ERA5 data (below) supports the idea that really unusual warmth occurred near the coast but not so much inland.


April was another windy month in the northern interior, according to ERA5, and this has been a common theme since November, if the model is to be believed.  ERA5 also shows a wet month in the western Alaska Peninsula, in contrast to the NOAA data.  For what it's worth, Cold Bay has mostly complete data and reported less than normal precipitation for the month; but more work would be needed to comment any further on the discrepancy.

No comments:

Post a Comment