Winter 2013-14 medium range discussion

[donsutherland1]

Don,

 

I haven't been on this forum in a while, but it's great to see you posting regulary. As you're aware, it's been quite cold over in my neck of the woods (NW Wa), but unfortunately it wasn't snow filled like I was hoping. It's currently 19* with decent winds out of the north and a wind chill of 9*.

 

Anyways, I was wondering what your thoughts were regarding the timeframe immediately following the one above. I don't have access to the Euro weeklies, but Brett Anderson's interpretations for the 23rd-29th timeframe shows cold and snow immediately north of the Canadian border. By this time, it looks as if the MJO will be returning to the Indian Ocean. If the AO continues to remain positive and the EPO continues to remain negative, history presents us with strong signal for a SE Ridge and a -PNA pattern. You've mentioned that the EPO is likely to head towards neutral soon, the forecasts just don't reflect this yet (Not saying you're wrong at all though). 

 

 

 

If we were in fact to have an MJO over the IO with a -EPO/+AO combo, here's what the anomaly chart would look like. Would love to hear your input on whether you see this as a possiblity or not. Thanks!

 

 

 

That's about 4 weeks out, so it's tough to have much confidence in details right now. The PNA- has been the predominant regime and the PDO- supports a continuation of a generally negative PNA. To what extent and how quickly the ridge retrogrades will determine when or if it goes neutral/positive. After mid-month it will begin approaching the historical record for a continual negative state, so we'll have to see how things play out. Even if it does go neutral/positive, that could be short-term in nature. FWIW, the January CFSv2 forecast would be consistent with an EPO+/AO+ setup, but the CFSv2 has no real skill from this far out.

[Srain]

Temperature departures across much of Texas are running anywhere from -30 to -40 degrees below normal. This has been an impressive early season Arctic air mass in our part of the CONUS.

[Eyewall2005]

Don any chance any of this cold airmass will eventually spill into florida? Not enjoying this summer time wx during xmas :0(

[donsutherland1]

Don any chance any of this cold airmass will eventually spill into florida? Not enjoying this summer time wx during xmas :0(

 

Without the development of blocking (AO going negative), most of the cold air will not reach Florida. Any cool weather would be short-lived. Hopefully, things will change, but the ensembles are not encouraging.

[donsutherland1]

At Jordan, MT, the temperature fell to at least -42° this morning. That shattered the daily record of -37°, which was set in 1927. Today's frigid temperature was that city's first -40° temperature since January 12, 1998 when the temperature also fell to -40°. It was also that city's first December temperature of -40° or below since December 31, 1992 when the temperature reached -40°. It was the coldest reading since December 22, 1989 when the thermometer fell to -45°. Finally, it was the earliest -40° temperature on record beating the previous early date of December 21, 1989.

[Portastorm]

Temperature departures across much of Texas are running anywhere from -30 to -40 degrees below normal. This has been an impressive early season Arctic air mass in our part of the CONUS.

 

Fascinating to at least this amateur eye how much the Pacific signals control the weather in Texas/Southern Plains.  The EPO has basically said "AO/NAO, I could care less what you say.  This is how it is."  WIll the EPO stay negative as long as we see figurative "bath water" temps in the NE Pacific and ridging persisting?

[SnoSki14]

The EPO has managed to completely override most of the negative signals so far being the +AO/NAO and -PNA. The strength of the cold air out west probably has to do with the +AO as I believe it keeps Canada and north cold.

Having a cold source region is creating these crazy negative departures out west.

[Met1985]

At Jordan, MT, the temperature fell to at least -42° this morning. That shattered the daily record of -37°, which was set in 1927. Today's frigid temperature was that city's first -40° temperature since January 12, 1998 when the temperature also fell to -40°. It was also that city's first December temperature of -40° or below since December 31, 1992 when the temperature reached -40°. It was the coldest reading since December 22, 1989 when the thermometer fell to -45°. Finally, it was the earliest -40° temperature on record beating the previous early date of December 21, 1989.

Wow very impressive cold for anytime of the year Don. To think I was looking to move out there sometime. I saw were they are having power outages because of the severe cold out there.

[tacoman25]

This morning's low temperature at Havre, MT has so far been -39°. That reading is its third consecutive daily record low temperature and its coldest reading during the 2000-present period.

 

Its readings for the past two days have been:

 

12/5 High: -14° (broke daily record of -12°, 1880); Low: -28° (broke daily record of -27°, 1956)

12/6 High: -13°; Low: -38° (broke daily record of -31°, 1972

 

The 12/5 high was also the lowest high temperature during the 2000-present period

 

The -39 was the coldest temperature for Havre this early in the season since 1897.

[Jonger]

The -39 was the coldest temperature for Havre this early in the season since 1897.

 

They had a -43 departure yesterday.

[Ji]

What's this don?

[QcSevereWx]

Looks cold, that was to be expected.

but..

ftp://ftp.cdc.noaa.gov/Public/gbates/reforecast2/teleconn/4panel.png
I see some red at the end of the tunnel.

[tacoman25]

Eugene OR hit -10 this morning. That's their second coldest temperature on record. Only colder was -12 in December 1972.

[clskinsfan]

If it does I feel it will pretty much kill winter for NYC south.

Do you ever feel anything else. Every post you make is about how 40 south is screwed.

[Ginx snewx]

ESRL has PNA up, EPO still down, LR ENS still cold.

[Ji]

saw something today on weather bell about a possible stratospheric warming happening?

 

http://www.cpc.ncep.noaa.gov/products/intraseasonal/temp30anim.shtml

[tacoman25]

12z Euro shows wave after wave of extreme cold invading the West/Central U.S. over the next week or so. Day 7 is particularly extreme, with sub -30C into Montana. Widespread daily anomalies of -25 to -30F are likely with this, with possible weekly anomalies in some areas of -15 to -20F.

 

It turns out I underestimated this cold wave, as most of MT had a weekly anomaly greater than -25. Don't see this very often.

 

 

[tacoman25]

As far as the medium range goes, it does look like there will be a relaxation period of the -EPO block as Don has asserted. However, there is growing consensus among the models that another NE Pacific ridge will quickly form in the 8-10 day period. The big question is whether or not this ridge will merge with the big height anomalies over Siberia to create another -EPO block similar to what we just saw.

 

 

[Jonger]

It turns out I underestimated this cold wave, as most of MT had a weekly anomaly greater than -25. Don't see this very often.

 

 

7dTDeptUS.png

 

This is like the opposite of March 2012, this one month will define the entire yearly anomaly for Montana.

[Jonger]

-51F departure for a single day... I haven't seen too many positive or negative departures close to this, well... ever.

[tacoman25]

Most models are leaning towards a return to -EPO after a brief respite.

 

 

[donsutherland1]

It turns out I underestimated this cold wave, as most of MT had a weekly anomaly greater than -25. Don't see this very often.

 

 

7dTDeptUS.png

The cold was very impressive. In many places, it actually wound up overperforming relative to MOS.

[MattHugo81]

With a general 500hPa anom pattern like this, the outlook for cold and wintry conditions here in the UK and many central and western areas of Europe is particularly grim...

 

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

Whether cold or warm bias in terms of personal choice through the winter, the outlook for the UK is extremely irritating and tiresome in terms of a relentless Atlantic flow. With the European high being extremely slow moving combining with the primary PV over E Canada/Greenland the UK is in a textbook +NAO pattern for the foreseeable. As the deep cold of Canada filters into the W Atlantic to create, at times, quite an extreme baroclinic environment, the outlook is mild, wet and windy, if not potentially stormy at times.

 

Excluding the exceptional and clearly rare December 2010, in terms of synoptics, the last few Decembers have been poor in terms of broader synoptics for the UK, Europe and also the N Hem in general. It's not until January and February that the situation has often become 'interesting' given SSW events. However, even that looks slim this year given QBO phase etc, clearly not impossible, but not as likely as say was the case earlier this year.

 

All cold fans in the UK wish you guys over in E Canada and E USA would stop hogging all that cold arctic air! Clearly once this type of synoptic pattern and height anom becomes 'locked in' it is very difficult to shift and I can't see the PV moving away from where it is now for some considerable time.

 

Yet another green, mild, and damp Christmas and festive period on the cards over this side of the pond. Yuck

 

Regards, Matt.

[donsutherland1]

Verification:

December 1-7, 2013

 

In Message #94 (11/20), I had noted:

 

The generally cold pattern now underway and likely to be reinforced from time to time with fresh shots of unseasonably cold air is likely to continue during the first week in December. Both the ENSO-teleconnection cases and objective analogs from the GFS ensembles centered around 12/1 are in good agreement that the eastern third to half of the U.S. and a large part of Canada will be colder than normal.

 

Most of what was shown on the ensembles at the time, the objective analogs, and the ENSO-teleconnection cases proved incorrect. The biggest variable responsible was that at the time, the ensemble forecasts showed a period of blocking (AO-) that would last into the first week of December before yielding to a new AO+ regime. Instead, the blocking lasted just 4 days, ending on November 25. Taking the ENSO-Teleconnections that actually prevailed would have yielded a closer outcome. Although that provides no consolation for what was a bad forecast (except for Canada where cold generally prevailed), it does provide a degree of confidence that a key premise concerning the state of the blocking played a critical role in the difference between the posted idea and what actually occurred. 

 

The relevant charts:

 

 

[NJwinter23]

With a general 500hPa anom pattern like this, the outlook for cold and wintry conditions here in the UK and many central and western areas of Europe is particularly grim...

 

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

Whether cold or warm bias in terms of personal choice through the winter, the outlook for the UK is extremely irritating and tiresome in terms of a relentless Atlantic flow. With the European high being extremely slow moving combining with the primary PV over E Canada/Greenland the UK is in a textbook +NAO pattern for the foreseeable. As the deep cold of Canada filters into the W Atlantic to create, at times, quite an extreme baroclinic environment, the outlook is mild, wet and windy, if not potentially stormy at times.

 

Excluding the exceptional and clearly rare December 2010, in terms of synoptics, the last few Decembers have been poor in terms of broader synoptics for the UK, Europe and also the N Hem in general. It's not until January and February that the situation has often become 'interesting' given SSW events. However, even that looks slim this year given QBO phase etc, clearly not impossible, but not as likely as say was the case earlier this year.

 

All cold fans in the UK wish you guys over in E Canada and E USA would stop hogging all that cold arctic air! Clearly once this type of synoptic pattern and height anom becomes 'locked in' it is very difficult to shift and I can't see the PV moving away from where it is now for some considerable time.

 

Yet another green, mild, and damp Christmas and festive period on the cards over this side of the pond. Yuck

 

Regards, Matt.

 

Hey Matt,

 

The +AO/NAO is certainly doing its dirty work for you guys over there as one would expect. Anything but the case here in the U.S. thus far with the cold anomalies we've seen since November. Our own upstream pattern over the Pacific is to thank.

 

I agree with your assessment on the vortex situation and the probably lower than usual chances for an SSW for late winter, however, there is some hope. Winter has behaved quite similarly to a 1990-91 thus far and that winter had a split for February that produced big time for the UK,  it ended up torching NA. 

[MattHugo81]

Hey Matt,

 

The +AO/NAO is certainly doing its dirty work for you guys over there as one would expect. Anything but the case here in the U.S. thus far with the cold anomalies we've seen since November. Our own upstream pattern over the Pacific is to thank.

 

I agree with your assessment on the vortex situation and the probably lower than usual chances for an SSW for late winter, however, there is some hope. Winter has behaved quite similarly to a 1990-91 thus far and that winter had a split for February that produced big time for the UK,  it ended up torching NA. 

 

Yeah, it's definitely a waiting game this side of the pond, that's for sure. I don't think many would be disappointed if a repeat of Feb 91 did happen, as, for example, it produced the following synoptics;

 

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910207.gif

 

As is usually the case, some who crave winter cold are already writing it off because of the up coming patterns, but clearly on the 11th of December that's crazy talk. A long way to go and particularly given the events of back in March of this year, primarily down to the SSW, March can sometimes provide a "winter lifeline" under the right synoptics. It's a case of sit and wait to hopefully see a gradual change in the evolution of the broader synoptic patterns, hope for some mountain torque events as well, so get some wave 1 and 2 activity going. I have a feeling, given current situations, that this polar vortex this winter season is going to take some 'beating down', it sure is noteworthy and 'powerful' at the present time, clearly not just within the trop but well up into the strat as well.

 

Cheers, Matt.

[tacoman25]

With a general 500hPa anom pattern like this, the outlook for cold and wintry conditions here in the UK and many central and western areas of Europe is particularly grim...

 

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

Whether cold or warm bias in terms of personal choice through the winter, the outlook for the UK is extremely irritating and tiresome in terms of a relentless Atlantic flow. With the European high being extremely slow moving combining with the primary PV over E Canada/Greenland the UK is in a textbook +NAO pattern for the foreseeable. As the deep cold of Canada filters into the W Atlantic to create, at times, quite an extreme baroclinic environment, the outlook is mild, wet and windy, if not potentially stormy at times.

 

Excluding the exceptional and clearly rare December 2010, in terms of synoptics, the last few Decembers have been poor in terms of broader synoptics for the UK, Europe and also the N Hem in general. It's not until January and February that the situation has often become 'interesting' given SSW events. However, even that looks slim this year given QBO phase etc, clearly not impossible, but not as likely as say was the case earlier this year.

 

All cold fans in the UK wish you guys over in E Canada and E USA would stop hogging all that cold arctic air! Clearly once this type of synoptic pattern and height anom becomes 'locked in' it is very difficult to shift and I can't see the PV moving away from where it is now for some considerable time.

 

Yet another green, mild, and damp Christmas and festive period on the cards over this side of the pond. Yuck

 

Regards, Matt.

 

Wasn't December 2009 pretty cold for you guys as well?

 

Anyway, Europe and Asia have hogged the cold for the past couple winters, it's North America's turn.

[tacoman25]

Verification:

December 1-7, 2013

 

In Message #94 (11/20), I had noted:

 

The generally cold pattern now underway and likely to be reinforced from time to time with fresh shots of unseasonably cold air is likely to continue during the first week in December. Both the ENSO-teleconnection cases and objective analogs from the GFS ensembles centered around 12/1 are in good agreement that the eastern third to half of the U.S. and a large part of Canada will be colder than normal.

 

Most of what was shown on the ensembles at the time, the objective analogs, and the ENSO-teleconnection cases proved incorrect. The biggest variable responsible was that at the time, the ensemble forecasts showed a period of blocking (AO-) that would last into the first week of December before yielding to a new AO+ regime. Instead, the blocking lasted just 4 days, ending on November 25. Taking the ENSO-Teleconnections that actually prevailed would have yielded a closer outcome. Although that provides no consolation for what was a bad forecast (except for Canada where cold generally prevailed), it does provide a degree of confidence that a key premise concerning the state of the blocking played a critical role in the difference between the posted idea and what actually occurred. 

 

The relevant charts:

 

 

However, since the 7th temperatures have been markedly cooler for the eastern half of the nation, and the first half of December will likely end up well below normal for the vast majority of the nation, including the Northeast.

[donsutherland1]

However, since the 7th temperatures have been markedly cooler for the eastern half of the nation, and the first half of December will likely end up well below normal for the vast majority of the nation, including the Northeast.

Correct and so far, so good for my 12/8-15 idea.

[1900hurricane]

FWD has begun dipping their toe into the medium range.

 

.LONG RANGE FORECAST...
...FOR THE 8 TO 12 DAY FORECAST PERIOD...
...THURSDAY DEC 19 THROUGH MONDAY DEC 23...

THERE WILL BE A POTENTIAL FOR A SIGNIFICANT COLD OUTBREAK ACROSS
NORTH AND CENTRAL TEXAS THAT COULD START JUST BEYOND THE 7 DAY
FORECAST PERIOD. GIVEN THE EXTENDED RANGE...THERE IS STILL
CONSIDERABLE UNCERTAINTY ON POTENTIAL IMPACTS. A CLOSE INSPECTION OF
THE LATEST 42-MEMBER NORTH AMERICAN ENSEMBLE (NAEFS) SUGGESTS THAT
THE LOWER END OF POTENTIAL IMPACTS WILL BE A RELATIVELY SHORT /TWO
TO THREE DAY/ PERIOD OF MUCH-BELOW NORMAL TEMPERATURES WITH LITTLE
OR NO WINTRY PRECIPITATION ACROSS NORTH AND CENTRAL TEXAS. THE UPPER
END OF THE IMPACTS SUGGEST A 3-4 DAY PERIOD OF MUCH-BELOW NORMAL
TEMPERATURES WITH A CHANCE FOR WINTRY PRECIPITATION IN MANY AREAS OF
NORTH AND CENTRAL TX.

BASED ON THE LAST 3-4 RUNS OF THE NAEFS...CONFIDENCE IS GROWING THAT
A VERY COLD ARCTIC AIRMASS WILL BEGIN SPREADING INTO NORTH TEXAS ON
DEC 19 OR DEC 20. THE FORECAST 500 MB PATTERN AND FORECAST MID LEVEL
TEMPERATURES ACROSS SOUTHERN CANADA STRONGLY SUPPORT A SOUTHWARD
PLUNGING AIRMASS AT LEAST AS COLD AS THE AIRMASS THAT ARRIVED IN
TEXAS ON DEC 5-6. THIS MORNINGS /12Z/ DETERMINISTIC RUNS OF BOTH THE
GFS AND ECMWF SUGGEST THAT THE INITIAL COLD SURGE WILL ARRIVE LATE
THURSDAY DEC 19 OR FRIDAY DEC 20. IF THE FORECAST HOLDS TRUE...THEN
TEMPERATURES AVERAGING 20-25 DEGREES BELOW NORMAL CAN BE EXPECTED
OVER ALL OF NORTH AND CENTRAL TEXAS OVER THE WEEKEND DEC 21-22.

THE PRECIPITATION FORECAST AT THIS EXTENDED RANGE IS MUCH MORE
PROBLEMATIC AND A GREAT DEAL OF UNCERTAINTY EXISTS REGARDING WINTRY
PRECIPITATION AND ANY POTENTIAL IMPACTS. THE NAEFS...WHICH IS
ESSENTIALLY 42 INDIVIDUAL MODEL RUNS USING TWO SEPARATE PHYSICS
PACKAGES...SHOWS A HUGE RANGE OF POTENTIAL IMPACTS. THAT HUGE RANGE
IS TYPICAL WITH ANY STRONG SYSTEMS IN THE 8 TO 12 DAY FORECAST
PERIOD. BUT GIVEN THE INCREASING CHANCES THAT VERY COLD AIR WILL
BE IN PLACE FOR THE PERIOD DEC 20-23...ANY PRECIPITATION THAT
FALLS ACROSS NORTH OR CENTRAL TEXAS COULD HAVE SIGNIFICANT IMPACTS.

09/PATRICK