TX Winter Wx Threat # 9--- Another Arctic Outbreak?

[southerngale]

Hector,
What are mets like him looking at that make them believe it isn't coming here? From what I've seen posted here, it looks like it will, or probably will. I'm just wondering if he is trusting different models or is believing the GFS surface temps over the look of the whole pattern. I can see everyone thinking it might or might not occur, but I just wonder what makes 2 mets see things so differently. I hope that made sense....I'm tired. lol

[Shoshana]

The Austin American Statesman has an article about the cold front - and the debate over whether it's actually going to get very very cold here.

I don't remember the last time the news was that the Weather guys don't agree!

Bitter weather might be headed Austin's way

Some of the coldest weather Austin has seen in a decade might be blowing through just in time for Super Bowl Sunday — or will it?

Local meteorologists disagree about whether an expected cold front next weekend will bring lows in the teens or just slightly lower than normal temperatures.

[southerngale]

Interesting, Shoshana. And at first I thought this would be easier to forecast than the last one. lol

This is what our 3 local stations here are saying, and the NWS. KFDM met has talked about it more on the KFDM board. This is just what is currently on the Weather pages online. I've been checking the local NWS discussions and I haven't seen them mention it at all, but the overnight discussion isn't out yet, so perhaps they'll bring it up.

KFDM: In the extended range, we still look to be under the threat of a major arctic outbreak with the initial surge on Thursday with progressively colder weather during the first weekend in February. It will be something that we will be watching closely.

KBMT: A large ridge of high pressure is forecasted to build from the North Pole southward along the West Coast by next weekend. That arrangement will force true Arctic air southward into the Continental U.S. The big question is will it go east through the Great Lakes giving us a glancing blow or head due south. The air mass is nearly as cold as the Siberian Express/Pipe Buster we experienced in Decemeber 1989. Still too early to tell how much cold air is coming so continue to check back to KBMT12.com for further updates this weekend as we continue to refine our numbers.

KBTV: No mention

NWS: No mention

[Extremeweatherguy]

after a good mention of the possible cold snap in yesterday afternoon's Houston AFD, it seems like the morning shift is not so bullish...

This is all they said:

BY TUESDAY...ANOTHER COASTAL TROUGH WILL DEVELOP AND ANOTHER S/WV
WILL CROSS TEXAS. MORE RAIN DEVELOPING MON NITE AND TUES. UPPER
FLOW REMAINS OUT OF THE SOUTHWEST THIS WEEK...SO LITTLE DIURNAL
CHANGE IN TEMPS ARE EXPECTED WITH PERIODS OF LIGHT RAIN THROUGH
FRIDAY. A LARGE EAST COAST TROUGH WILL RETROGRADE WEST BY SATURDAY.
THE UPPER FLOW WILL BECOME W-NW AND MAYBE WE CAN GET AN EXTENDED
BREAK IN THE RAIN BEGINNING SATURDAY AND PERSISTING THROUGH EARLY
NEXT WEEK

I mean, come on. We are looking at a possible serious cold snap here and all they say is that we may see a W-NW flow and some clearing skies? Also...what happened to the cloudy skies and low pops the afternoon shift called for next weekend (as well as the "polar bear" watch)? I have a feeling the morning shift may be only relying on the model output numbers and are not paying much attention to the other information.

[KatDaddy]

Dallas AFD states the pattern is nothing compared to 83 or 89:

DO NOT SEE ANYTHING IN
THE MODEL FORECASTS OF THE UPPER LEVEL PATTERN THAT RESEMBLES THE
HISTORIC ARCTIC OUTBREAKS OF 1983 AND 1989...BUT THIS CERTAINLY
MAY SHAPE UP TO BE THE COLDEST 3-4 DAY STRETCH SEEN IN YEARS.

[Portastorm]

Shoshana ... that's a great post and interesting article. I hadn't seen it yet.
The quote below from the NWS forecaster in the Austin/San Antonio office kinda makes you scratch your head and wonder what he's looking at (besides the GFS model).

Here's the quote:

"Forecaster Pat McDonald at the National Weather Service disagrees with the prediction, however, saying that temperatures in Canada and Alaska aren't cold enough to produce those types of arctic fronts.

"We need to see strong high pressure currents from Canada and snow across the country for it to get that cold, and I am not seeing those," McDonald said. "

[Extremeweatherguy]

Dallas AFD states the pattern is nothing compared to 83 or 89:

DO NOT SEE ANYTHING IN
THE MODEL FORECASTS OF THE UPPER LEVEL PATTERN THAT RESEMBLES THE
HISTORIC ARCTIC OUTBREAKS OF 1983 AND 1989...BUT THIS CERTAINLY
MAY SHAPE UP TO BE THE COLDEST 3-4 DAY STRETCH SEEN IN YEARS.

yeah, Dallas and Houston probably will not get that cold, but the actual pattern is somewhat similar. High temperatures may actually get down to '83 and '89 levels for a day or so if this thing hits head on..which I think is what JB is expecting with his forecast of highs in the teens in Dallas and twenties in Houston.

[Extremeweatherguy]

Shoshana ... that's a great post and interesting article. I hadn't seen it yet.
The quote below from the NWS forecaster in the Austin/San Antonio office kinda makes you scratch your head and wonder what he's looking at (besides the GFS model).

Here's the quote:

"Forecaster Pat McDonald at the National Weather Service disagrees with the prediction, however, saying that temperatures in Canada and Alaska aren't cold enough to produce those types of arctic fronts.

"We need to see strong high pressure currents from Canada and snow across the country for it to get that cold, and I am not seeing those," McDonald said. "

yeah, that last quote really makes you say...HMMM.

No snow across the country?

http://www.ssd.noaa.gov/PS/SNOW/DATA/cursnow_usa.gif

Then what may I ask is that white stuff to our north? lol.

[KatDaddy]

All we need is depth for the cold air and weak disturbances to bring us snow. I can do without the extreme cold.

[TampaFl]

EWG, JB in some of his discussions Friday & last night is now looking at the 1994 analogs for this up coming shot of artic air. What are your thoughts & comments on this??

[Air Force Met]

Dallas AFD states the pattern is nothing compared to 83 or 89:

DO NOT SEE ANYTHING IN
THE MODEL FORECASTS OF THE UPPER LEVEL PATTERN THAT RESEMBLES THE
HISTORIC ARCTIC OUTBREAKS OF 1983 AND 1989...BUT THIS CERTAINLY
MAY SHAPE UP TO BE THE COLDEST 3-4 DAY STRETCH SEEN IN
YEARS.

Something tells me this person hasn't looked at the pattern from 83 or 89 (Feb or Dec) lately. Looking at either one of those outbreaks from the upper pattern ALONE...you would NEVER forecast an arctic outbreak. The flow was zonal all the way across the US...especially in Feb '89 (the longer duration of the 89 events)...and in the 1983 event. The only diff there was the polar vortex was over the northern US...but it was still zonal all the way to Montana.

The pattern here is a flow all the way from Siberia to Kansas...you didn't have that in any of the other outbreaks...they didn't have a great upper air pattern...but what they did have...and RESEMBLES this one is the huge ridge in northern AK nudging into the north pole.

And what they had that this one...so far...is lacking...is massive domes of high pressure at the sfc...cold very dense air just sitting there waiting to be kicked out by the building ridge. So far...that is what is missing.

So...it has nothing to do with the upper pattern What is lacking here can be (or not be) found at the sfc. Those little pidly 1030 highs will get kicked to the east...and the cold air is going to have to come from somewhere else...because in our traditional arctic outbreaks it comes from NW Canada and AK (in 1983/1989/Jan 1978)...and right now...it's in the teens in the Yukon Territory! Fairbanks is expecting a high in the 20's today...so the cold air will have to come from somewhere else...and I am not sure it will be accompanied by enough high pressure to make it this far south.

Yes, we'll cool down a good bit...but unless something changes...it won't be frigid like those other years. You need more than a great upper level pattern...you needthe sfc features too...and that's still up in the air.

[Air Force Met]

Shoshana ... that's a great post and interesting article. I hadn't seen it yet.
The quote below from the NWS forecaster in the Austin/San Antonio office kinda makes you scratch your head and wonder what he's looking at (besides the GFS model).

Here's the quote:

"Forecaster Pat McDonald at the National Weather Service disagrees with the prediction, however, saying that temperatures in Canada and Alaska aren't cold enough to produce those types of arctic fronts.

"We need to see strong high pressure currents from Canada and snow across the country for it to get that cold, and I am not seeing those," McDonald said. "

yeah, that last quote really makes you say...HMMM.

No snow across the country?

http://www.ssd.noaa.gov/PS/SNOW/DATA/cursnow_usa.gif

Then what may I ask is that white stuff to our north? lol.

He's wrong about the snow...but he's right about the pressure not being high enough and the temps not being low enough to produce those types of fronts. Every arctic outbreak we have had has been a result of cold temps in AK.

As I said a couple of days ago...this airmass has been tapped twice. This also happened last year...remember? Great upper level pattern...but the air had ben tapped a couple of times (to the east) and I pointed out then...there was nothing in the source region. Sure...it will feel like winter...but it won't be historic. Plus...these types of flows are usually very dry for us. The days we get the highs below freezing are typically overrunning situations...unless it is a true 1983 type situation.

Now...if some cold air can get trapped under the polar vortex and then get send south, that would be different. I see the Euro trying to set that up after day 7...we'll see if that verifies.

[Air Force Met]

EWG, JB in some of his discussions Friday & last night is now looking at the 1994 analogs for this up coming shot of artic air. What are your thoughts & comments on this??

I hate to answer his question...but I wanted to talk about this because it jives with what I was saying...

1994 sent a cold shot south and east....mostly east. The upper level and sfc pattern is similiar. In 94 the polar vortex was further west during the first wave.

In SETX...it got cold on two different days...nothing significant. Most of it went east. There were big problems in the midwest...especially in the middle of the month with lows below zero for days with the second shot, and that upper level pattern is almost identical to this one. The other similarity is the lack of really high pressure at the sfc....which is why it went east instead of diving south.

[Air Force Met]

EWG, JB in some of his discussions Friday & last night is now looking at the 1994 analogs for this up coming shot of artic air. What are your thoughts & comments on this??

Here is a comparison:

1994 -

http://vortex.plymouth.edu/cgi-bin/gen_ ... ge=912x650

The 216 hr forecast...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_216m.gif

[Kennethb]

Concur with AFM. Not all strong arctic blasts create severe cold in the south. Many times over the years, the Midwest is sitting below zero, while we get our regular below normal cold of lows in the 20s and highs in the 40s.

[Air Force Met]

Concur with AFM. Not all strong arctic blasts create severe cold in the south. Many times over the years, the Midwest is sitting below zero, while we get our regular below normal cold of lows in the 20s and highs in the 40s.

That's what I am starting to think will happen...lows in the 20's for a day or two and a day or two with highs in the 40's...colder up in DFW...teens/30's. Since this will be a NW flow type of event...and there isn't really any constant shots of cold air coming down...I don't see a lot of overrunning to keep the air from modifying this far south. So...certainly below normal lows and highs. Lows...15 or so below normal...highs...10-15 degrees...so overall about 12-15 degrees below normal...give or take a couple of degrees.

Either way...I'll have winter. I get to go to Colorado Springs on the 5th for a conference

[aggiecutter]

If what AFM says verifies, and the models are heading that direction this morning, all of them are, then it will be a cool to cold week and maybe one very cold day, friday or saturday. Things could change, but that's the way it looks right now.

[pwrdog]

Lowest temps I can find this morning...

Canada -45 NWT is 10 degrees below normal- temps expected to rise.

NE Greenland -46 is +1 above normal - forecast temps to fall to at or below normal

NC Russia -45 is +4 degrees above normal- forecast temps to fall to at or below normal

Northway Alaska -19 above normal by 6 degrees F. forecast temps to rise even more above normal.

So there is some cold air over the ice cap in a few places but mostly at or above normal--- Except near Eureka N. W. T. where temps are 10 degrees below normal but that is where part of the this cold snap should draw air from..IMO.

[aggiecutter]

Bastardi has been using the 94 analog for 5-6 days now. I mentioned it a couple days ago on here as I was concerned that the brunt of the cold would go to the North and East of Texas.

[Air Force Met]

Lowest temps I can find this morning...

Canada -45 NWT is 10 degrees below normal- temps expected to rise.

NE Greenland -46 is +1 above normal - forecast temps to fall to at or below normal

NC Russia -45 is +4 degrees above normal- forecast temps to fall to at or below normal

Northway Alaska -19 above normal by 6 degrees F. forecast temps to rise even more above normal.

So there is some cold air over the ice cap in a few places but mostly at or above normal--- Except near Eureka N. W. T. where temps are 10 degrees below normal but that is where part of the this cold snap should draw air from..IMO.

First of all...we won't ever get air from NE Greenland...and it's always cold there in the winter..well...usually. Also...the air in Russia is usually cold too...which is seen in the fact it is near normal. And...while that air in Russia is cold...it's not that dense. The pressures there are 1020-1025 MB...with one report of 1040 in the coldest area...but that's in a vally and it's usually a high reading. So...there is no high pressure cell for that cold air to be transported with across the poles by the cross polar flow.

-19 in AK...by the time it works it way all the way south...and modifies...doesn't mean much. Classic cold snaps begin with MUCH colder air and much higher pressures. For instance...in Feb 1989...Northway AK had a pressure of 1078 MB and temps 50F colder...and that put us into the 20's in SETX....so do the math.

The problem is the lack of high pressure. There is an old rule of thumb in our LAFP binder (basically a forecasters rule of thumb book used in days when you didn't have fancy computers) that says look for the 1050mb plus high over Canada/AK and watch for a 1045mb high or greater to pass through Montana. If that happens...an arctic boundry will pass through SETX within 48 hours. Also watch Barrow AK temps. ONce they pass 20 degrees above normal (which is the ridge building) and you have the highs...you will get your arctic front.