Cold air over the US

NZstorm · Unread post by **NZstorm** » Tue 07/01/2014 07:09

Check out this observed sounding from the upper midwest today (in Minnesota)!

They have been getting lake effect snow with this.

Chicago Ohare Airport had a record low temp of -27C today.

jamie · Unread post by **jamie** » Tue 07/01/2014 07:47

Amazing! I've been following this event.

What's lake effect snow?

NZstorm · Unread post by **NZstorm** » Tue 07/01/2014 08:16

Lake effect snow is convective snow showers forming over the relatively warm lake.

Manukau heads obs · Tue 07/01/2014 09:10

relative ....the lake edges have floating ice....i.e the lake itself will be me much above freezing
but that is as you say alot warmer than -25c!
(i.e so the air mass picks up moisture but quickly becomes saturated)

NZstorm · Unread post by **NZstorm** » Tue 07/01/2014 10:07

Todays forecast sounding for upstate New York at Lake Erie.

Amazing to see instability at such cold temperatures. The layer of warming/instability up to 700mb is due to the lake!

Simon Culling · Unread post by **Simon Culling** » Wed 15/01/2014 11:27

There was a lot of comment in the media in the UK about the cold spell in N America being due to the 'Polar Vortex' moving south from the North Pole. The impression was given that the polar circulation effectively moved south away from the pole when in fact it was more a case of there being 'leakages' of cold air to mid-latitudes as this good post on the NOAA website explains:

http://www.climate.gov/news-features/ev ... r-outbreak

Whilst I have not seen reports of any all time national records being broken, there were certainly plenty of new local records.

NZ Thunderstorm Soc · Mon 14/01/2019 22:17

Some cold air moving over the USA at the moment, but that's nothing unusual for this time of year as it is winter over there.

Chris W · Unread post by **Chris W** » Wed 30/01/2019 13:40

It is very unusual in terms of the depth of cold, and how far south the polar vortex has moved after being split. Chicago is in for a -33C minimum and wind-chill to -46C according to the BBC. Frostbite is possible within 10 minutes of being outside and the Chicago River is freezing over.

TonyT · Unread post by **TonyT** » Wed 30/01/2019 16:26

It is unusually cold, another SSW-led event, similar to last winter but if anything even colder. Will we see another SSW event in our hemisphere for our coming winter?

Chris W · Unread post by **Chris W** » Wed 30/01/2019 18:19

I hope not, it was miserable!

Bradley · Unread post by **Bradley** » Thu 31/01/2019 11:18

Chicago hasn't been above -13F today which would be a record low maximum but it was -6F at midnight so does that means -6F will be counted as the maximum? Does anyone know how they measure a maximum temp in the US? Is the 24 hours from midnight to midnight or 9am to 9am?

Nev · Unread post by **Nev** » Thu 31/01/2019 19:49

Bradley wrote: ↑Thu 31/01/2019 11:18 Chicago hasn't been above -13F today which would be a record low maximum but it was -6F at midnight so does that means -6F will be counted as the maximum? Does anyone know how they measure a maximum temp in the US? Is the 24 hours from midnight to midnight or 9am to 9am?

I think the NWS use a midnight reset time. Chicago's O'Hare Airport had a T-max of -10F (-23C) recorded at 12:07am on Wed LT, and a T-min of -23F (-31C) recorded at 8:41am.

Bradley · Unread post by **Bradley** » Thu 31/01/2019 20:23

Nev wrote: ↑Thu 31/01/2019 19:49
Bradley wrote: ↑Thu 31/01/2019 11:18 Chicago hasn't been above -13F today which would be a record low maximum but it was -6F at midnight so does that means -6F will be counted as the maximum? Does anyone know how they measure a maximum temp in the US? Is the 24 hours from midnight to midnight or 9am to 9am?
I think the NWS use a midnight reset time. Chicago's O'Hare Airport had a T-max of -10F (-23C) recorded at 12:07am on Wed LT, and a T-min of -23F (-31C) recorded at 8:41am.

Thanks Nev, pity it doesn’t do 9am to 9am, the max would have been closer to -14F and may well have been an all time record...

tgsnoopy · Unread post by **tgsnoopy** » Thu 31/01/2019 21:19

Brr, thank heavens it's forecast to improve before I get there in a few days. Although I've only really looked at DFW/TX for arrival on Wednesday. Certainly could be a shock after the weather we are going through at the mo.

TonyT · Unread post by **TonyT** » Thu 31/01/2019 21:41

tgsnoopy wrote: ↑Thu 31/01/2019 21:19 Brr, thank heavens it's forecast to improve before I get there in a few days. Although I've only really looked at DFW/TX for arrival on Wednesday. Certainly could be a shock after the weather we are going through at the mo.

The warm up will only be 4-5 days, then back to current levels of cold or worse...

tgsnoopy · Unread post by **tgsnoopy** » Mon 04/02/2019 05:01

TonyT wrote: ↑Thu 31/01/2019 21:41The warm up will only be 4-5 days, then back to current levels of cold or worse...

Good call Tony. From what Kim told me, I'm now a little worried about models for Sun night/Mon Morn for the transit down from KS to TX for my return flight. Still a week out though. Shall be interesting transition for me for sure.

tgsnoopy · Unread post by **tgsnoopy** » Fri 08/02/2019 04:24

And the next arctic breath has started arriving. Temps yesterday in Dallas TX area were nice, but that's changed overnight. By this evening we will be below freezing, we should complete our drive to Wichita Falls TX ok this morning, before something akin to -10°C this evening. Hopefully the drive up through Lawton OK to Wichita KS tomorrow will be ok, but it will likely be below freezing. The Jet Stream is pulling the cold air over Colorado and Kansas this time so it will an interesting contrast for me.

tich · Unread post by **tich** » Fri 08/02/2019 20:27

https://sanfrancisco.cbslocal.com/2019/ ... aks-storm/

The US West Coast has also felt the chill. Nothing like the northern areas, but somewhat unusual compared to what they usually get.

tgsnoopy · Unread post by **tgsnoopy** » Sat 09/02/2019 13:00

Arrived in Wichita KS in time to do the Accuweather 4pm tour which was very informative. Roads were great, I35 had snow beside it & in center median etc North of OKC. River has significant ice in it & anywhere moisture has formed is frozen & slick, but so far so good. Our suite is on the top floor of the hotel with a huge TV and great views

Photo's to follow I expect. About to go down and register shortly.

tgsnoopy · Unread post by **tgsnoopy** » Sat 09/02/2019 13:32

A Couple of pics:

CC19 CC.jpg

CC19 Frozen River closer.jpg

CC19 Frozen River.jpg

NZ Thunderstorm Soc · Sat 09/02/2019 21:19

Did you see any linemen there, Glen?

tgsnoopy · Unread post by **tgsnoopy** » Sun 03/03/2019 11:04

tornado · Unread post by **tornado** » Sun 03/03/2019 15:18

ice tsnami wow

NZstorm · Unread post by **NZstorm** » Thu 14/03/2019 06:55

Wind at Denver Airport this morning is gusting 65knots, temp -2C, heavy snow.

An unusually deep low has developed on the lee side of the rockies with a record breaking low air pressure for Pueblo Colorado of 975.5mb MSL. Records date back to 1893

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