First, the cold: there have been a couple of reports of -50°F in the ongoing cold snap across the eastern interior, according to the NWS. The Birch Creek RAWS to the east of Circle Hot Springs reached the negative half-century mark yesterday evening, and the Robertson River co-op observer near Tanacross also measured -50°F this morning.
Also of note, Northway airport made it to -47°F this morning, colder than anything observed last winter.
Down in south-central Alaska, high winds hammered exposed locations throughout the weekend and were still causing big trouble today. The Palmer airport illustrates the extreme wind episode, with wind speeds gusting over 50mph more or less continuously since midnight on Friday night.
Here's a news article:
The peak gust of 85mph on Saturday morning is the highest credible wind gust reported from Palmer, with data back to 1973. [Update: Jim Green correctly notes that the "peak wind" section of the METAR actually reported higher gusts, as high as 100mph on Sunday morning.] Of course the usual caveats apply about changes in wind measurement instrumentation over the decades, and for the chart below I'm only showing results since 1997, when the ASOS platform was commissioned in Palmer. Also, the anemometer was upgraded to a sonic instrument in September 2006.
Prior to this weekend, the highest wind speed was observed in early January 2022, and that wind storm was also driven by a very strong north-south pressure gradient. Compare Saturday afternoon's MSLP and 500mb maps (below) with those from the 2022 event, as documented in the following blog post:
https://ak-wx.blogspot.com/2022/01/mat-su-wind-storm.html
In Saturday's post, I commented that the MSLP difference between Deadhorse and Seward was approaching an all-time record. According to ECMWF AIFS data (very similar to ERA5 reanalysis), the Deadhorse-Seward difference reached 59mb on Saturday afternoon, and the peak 24-hour average exceeded 56mb. Only one event in the ERA5 history (1950-present) had a higher 24-hour mean pressure difference: February 2-3, 1970.
This really has been an extreme event.
Multiple go arounds at ANC due to win hear, they were on a straight 33 configuration the whole weekend which is very rare. An Airvan also blew over when trying to exit the runway. Looks like a similar set up again in a week?
ReplyDeleteThat Low in the Gulf of Ak will drive our winter in Fairbanks.
ReplyDeleteYou're on the wrong side of it if you like warmer weather, that's for sure.
DeleteLooks like the next round of cold will be both deeper and more persistent for the central interior.
Wow, what a windstorm. The 85mph you cite as the top gust looks like it only considers the hourly gust figure. When I look at the peak wind section of the METARs I find quite a few higher than that, with the highest being 100mph! (87 kts).
ReplyDeleteMETAR PAAQ 071753Z 03047G69KT 9SM -SN CLR M08/M22 A2919 RMK AO2 PK WND 04087/1722 SNB1658 SLP891 P0000 60000 T10831222 11083 21106 55004
The wind event went had about a 60 hr duration with gusts occasionally breaking the 80 mph mark throughout.
At leas the temperatures were a little less severe than in some past events.
Ah yes, you're correct Jim - thank you. My database only includes wind speed and gust reported on the hour, not the "peak wind" section, so I overlooked the "peak wind" information for the historical comparison. I've added a note to the blog post.
DeleteAt or below -30*F thing's change for occupants. It becomes a move from dealing with the elements to risk management.
ReplyDeleteYes, I recall Rick writing that -30F is approximately the threshold for real difficulties in normal outdoor activities. At least for us moderns.
Delete