IbrChris

Interesting info, thanks for looking into it. There's probably a good reason why transportation wx stations (DOT or railroad) aren't considered official.

Which is funny cause Prospect Creek, Alaska was a DOT station iirc. -80 there is the national cold record.

Nice work. Wxstatman also reported new state record lows in Nevada and Nebraska, I believe.

What was the new Nevada record?

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Gorton’s Fisherman always tells it like it is.

Policy change at ECMWF now allows imagery (model run charts etc) and data (tables etc) to be shared publicly similar to the GFS and CMC/GEM.

It’s a long overdue change and a welcome one.

Pocatello, ID fell to -6 yesterday beating their all-time October record of 7 (10/31/2003) by 13 degrees! That record from 2003 was the only time they had dropped below 10 in October dating back to 1900.

Apparently the low yesterday was -46.1.

Yeah I went by the low in the 15 minute data...not sure where the -46.1 came from as it isn't shown in the 15 min data but it is shown in the 24h data. Rounds to -46 either way though.

A breakdown of this arctic event of 10/28-10/31/2019 in the Northwestern US comparing coldest temp of the event with coldest October temp on record prior to the event.

Oregon: -7 at Foster Flat. October record -14 at Foster Flat on 10/31/2002, official record -11 at Fort Rock and Seneca...both on 10/31/2002
Washington: 5 at several locations. October record -5 at Bumping Lake and Republic, both 10/31/1935
Idaho: -21 at Fairfield and Copper Basin. October record: -28 at Copper Basin 10/30/1991, however it beat the prior official Oct record of -16 at Big Springs on 10/30/1917.

Utah: -46 at Peter Sink. October record -32 at Peter Sink 10/31/2002
Montana: -25 at Whiskey Creek. October record -30 at Summit 10/31/1935
Wyoming: -29 at Saratoga and Old Faithful Lodge (YNP). October record -33 at Soda Butte (YNP) on 10/29/1917
Colorado: -23 at Fraser and -24 at Harbison Meadow. October record -20 at Westcliffe 10/28/1917
Arizona: -2 at Grand Canyon NP Airport. October record -9 at Fort Valley 10/21/1949

Two unofficial stations in Wyoming tied the state October record low (and the previous official lower 48 record low for October) - the -33 reading at Soda Butte in 1917.

 

This morning, -33 was observed at a Union Pacific weather station (UR345) and a Wyoming DOT station (WY56), both part of the MesoWest network. 

Not buying the Rock River reading (UR345) after seeing their high temp the day prior was around -14. I took a look at all the surrounding stations and there seems to be a cold bias at Rock River.

Here's the list of coldest official station October minimums for Wyoming as it appears right now:

 

-33 at Soda Butte (10/29/1917)

-29 at Saratoga (10/30/2019)

-27 at Old Faithful (10/30/2019)

-26 at South Pass City (10/31/1935)

This is what I have:

-33 Soda Butte (YNP) 10/29/1917

-29 Old Faithful Lodge (YNP) 10/30/2019

-29 Saratoga 4 N 10/30/2019

-27 Lake Yellowstone (YNP) 10/29/1917

-26 Big Piney Ap 10/30/2019

-26 Encampment 10/30/2019

-26 Keystone 10/30/2019

-26 Nugget Canyon 10/30/2019

-26 Sweetwater Station 4 SW 10/30/2019

-26 Recluse 14 NNW 10/30/1991

-7 at Foster Flat (Oregon's coldest)...far cry from the -14 on Oct 31, 2002 and didn't even beat the official OR record of -11 at Seneca and Fort Rock on Oct 31, 2002.

Some crazy cold minimums this morning in Wyoming:

 

-26 at Big Piney (prev. Oct record -15 in 1971)

-25 at Old Faithful (prev. Oct record -11 in 1991)

-22 at Saratoga (prev. Oct record -8 in 1972)

-20 at Rawlins Airport (prev. Oct record -7 in 1972)

 

In Idaho, -17 this morning at Island Park is a preliminary state record for October. The listed record is -16 at Big Springs in 1917. Island Park had also set the Idaho state record low for pre-10/15 readings when they fell to -3 in the earlier cold wave around the 10th this month. 

-21 at Copper Basin and -20 at Fairfield. Fairfield is a town in Camas County, ID and may go down as the new Oct state record low. -18 at Island Park. Surprisingly Stanley didn't post anything under -10...perhaps no snow cover over there.

-29 at Old Faithful Lodge (new station) while the Ranger Station fell to -25.

-23 at Randolph, UT (coldest ever at an inhabited place in Utah)

-26 at Keystone, WY

-25 at Foxpark, WY
-33 at Rock River, WY (UPR station...may be inaccurate but within realm of possibility given the -20 at Rawlins ASOS).

A new October record low temperature for the lower 48 states was set this morning when Peter Sinks, Utah fell to -45.5 between 2:15 and 2:30 am. The previous record was -34.5 set on October 28th (two days ago). The record prior to this year was -33 at Soda Butte, WY (Yellowstone National Park) on Oct 29, 1917.

The record for the entire US including Alaska is -48 at Clearwater, AK on Oct 31, 1975. Additionally -44 was recorded at Chandalar Lake, AK on Oct 26, 2008 and Clearwater, AK on Oct 30, 1975

Winter was ushered in with a bang this morning in Idaho Falls with a temp of 10 and wind gusts to 45 mph (wind chill around -12). Moderate snow at the same time led to a period of blizzard conditions.

Of note as well Pocatello (PIH) tied their all-time October low (7 degrees) yesterday *without* snow cover. With today's snowfall and winds going light overnight tonight, they'll almost certainly go below zero and potentially break their former October record low by 8-10 degrees!

Interestingly, there are a lot of places that have large diurnal changes in Utah, but in all those places it's the opposite season that has them.  November through March is the least likely time to have a huge dirunal change everywhere in Utah except Peter Sinks it seems.

Peter Sinks can still post some 60-ish degree diurnal swings in summer too. It has to do with the winds going calm allowing for a decoupling between the sink bottom and the rim. This decoupling can produce a 30-40 degree temp gradient over about a 300' elevation change. In summer the nights are shorter and hence the strength of the cold pool isn't as pronounced as winter when you have longer nights and snowcover.

32 degree rise in 15 minutes this morning (7:30 to 7:45 am)...-28 to 4 degrees (mean temp -16.6)

List of largest diurnal ranges at Peter Sinks (2010-2019):
 

74 degrees (28/-46) on 2/22/2010

73 degrees (39/-34) on 3/5/2013

72 degrees (41/-31) on 12/3/2017

70 degrees (35/-35) on 3/20/2010

68 degrees (47/-21) on 12/2/2017

68 degrees (25/-43) on 12/5/2016

68 degrees (47/-21) on 10/28/2010

67 degrees (36/-31) on 2/24/2015

67 degrees (41/-26) on 11/23/2015

67 degrees (18/-49) on 2/2/2011

66 degrees (24/-42) on 12/7/2017

66 degrees (42/-24) on 12/4/2017

66 degrees (24/-42) on 12/8/2016

66 degrees (35/-31) on 3/12/2014

65 degrees (34/-31) on 3/7/2018

65 degrees (37/-28) on 2/13/2017

65 degrees (36/-29) on 3/19/2016

65 degrees (28/-27) on 11/22/2015
65 degrees (37/-28) on 2/8/2010

I went through and calculated the monthly and annual mean extremes (the average warmest high and coldest low in a typical month/year).

Annual: 83/-47 (on average warmest day is 83 and coldest night is -47)
Jan: 41/-40
Feb: 41/-35
Mar: 49/-31
Apr: 58/-16
May: 65/-1
Jun: 78/18
Jul: 82/23
Aug: 81/20
Sep: 76/12
Oct: 65/-6
Nov: 51/-26
Dec: 43/-43

Period: Jan 2010-Oct 2019

It's noteworthy that Rawlins, WY fell to -16 this morning, likely the coldest ASOS temp in October in years.

My guess for Oct 1971 would be in the neighborhood of -38 to -40 at Peter Sinks.

Too bad Peter Sinks wasn't around for cold waves like Oct 1971. Could have hit -40 then. 

Well we have some data for Logan in Oct 1971

Logan Radio (https://wrcc.dri.edu/cgi-bin/cliMAIN.pl?ut5182) fell to 6 on the 30th

Logan USU Exp Stn (https://wrcc.dri.edu/cgi-bin/cliMAIN.pl?ut5190) fell to 8 on the 30th

Both stations may be a hair warmer than the current Cache County Airport site however. Still think given the 700 mb temps will be considerably colder than 1971 over N Utah that the odds favor colder temps than 1971.

Logan (KLGU) was 12 this morning and is forecast to hit 2 Wednesday morning...suggesting perhaps -45 at Peter Sinks later this week.

-34.7 this morning stands as the coldest October temperature ever recorded in Utah. It also beats the -33 at Soda Butte, WY in Oct 1917 for the coldest temp recorded in the lower 48 in October.

It is quite likely Peter Sinks flirts with or drops below -40 this week, the coldest period likely either Tuesday or Wednesday morning (Wednesday favored).

25.8C was the maximum sounding at SLE in August 1981, although 850's could have maxed out between the soundings. July 2006 had that number beat with 27.0C on the afternoon of the 22nd. Too bad we couldn't keep a clear sky that day.

Yeah, I don't expect any conv debris will spoil the fun this time. Personally I'm thinking PDX sees 108 on Thu and perhaps an isolated 110 shows up at one of the other ASOS, best chance probably in lee of Coast Range (HIO) or mid-valley (MMV, SLE).

For what it's worth, the 1981 ridge was more impressive in all aspects compared to what is currently advertised. 850's with that maxed out around 27c with that if memory serves.

Nice, you mind grabbing some reanalysis maps for the Aug 1981 event? It's looking like 28c/29c assuming the Euro Op/ensemble mean prevails.