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Medium/Long Range Discussion Part 2

IWXwx

By IWXwx,
in Lakes/Ohio Valley

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Ottawa Blizzard

Ottawa Blizzard

Posted
Posted

I'm seriously giggling with joy at the hints of hope in all your posts. I'll take the cold up here, we need solid frozen lakes for ice fishing. After the brutality of heat everyone has suffered in the lower Midwest and Ohio Valley... I can't wait to see the pics. Maybe even real tears on Chicagowx's face when he's got 2 feet on the ground with 50mph winds ripping.

CPC getting on board too... when was the last time we saw an 8-14 with no orange or red in the heartland? Look at the cold slowly oozing east and letting up in Alaska.post-1834-0-59926300-1355788948_thumb.gi

lol You have to laugh. Still has southern Ontario above average. It's as if this region has warmed more than any other over the past few years.

Environment Canada is going to nail this winter. Colder than average in western Canada, warmer than average in eastern Canada, including Ontario and Quebec. Take it to the bank.

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Chicago WX

Chicago WX

Posted
Posted

lol You have to laugh. Still has southern Ontario above average. It's as if this region has warmed more than any other over the past few years.

Environment Canada is going to nail this winter. Colder than average in western Canada, warmer than average in eastern Canada, including Ontario and Quebec. Take it to the bank.

http://www.cbc.ca/ne...ast-canada.html

Link to Environment Canada's winter forecast. Have to admit, it's looking good so far!

This thread is right up your alley: http://www.americanwx.com/bb/index.php/topic/38040-winter-1213-complaint-thread/

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Chicago WX

Chicago WX

Posted
Posted

a Month of hell, thanks for asking, hoping we get hammered.. this is my last winter in a somewhat snow world... course watch my luck Dallas-Fort Worth will get slammed next winter like they did right before the super bowl 2 years ago LOL

Moving to Texas? Woo, enjoy the heat. :D

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jhamps10

jhamps10

Posted
Posted

True enough my man. Though I had a friend move down to Austin this past Spring. He didn't like summer down there much. :lol:

heh, yeah the summers are pretty intense down there,

anyway if the GFS is right, it's going to be quite the interesting system next week in MO, IL, IN... first real shot of major winter precip for many north of 70

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OHweather

OHweather

Posted
Posted

12/18 mid-range thoughts:

-How long will the –NAO/AO last?

-Will the Pacific pattern become more favorable for the eastern lakes/OV?

-Is this week’s storm the first in a series?

post-525-0-93721800-1355814084_thumb.gif

Although western US troughing is persisting, an active sub-tropical jet appears to be taking hold in conjunction with west-based –NAO blocking for the first time since early November. Although the current trough across the Mississippi Valley isn’t producing a storm as originally thought possible, it is still helping to pump up heights over eastern Canada, re-enforcing the developing –NAO. The Euro ensembles show this block maintaining itself over the short term, ensuring that this late week storm tracks towards the east once it gets to the lower Great Lakes and pulls down a shot of cold air:

post-525-0-44937800-1355814123_thumb.png

In addition, strong central Pacific ridging, nosing into the Aleutians and even Canada, is ensuring that the strong PV does not slide into Alaska and flood the CONUS with Pacific air. In addition, this ridging is ensuring high-amplitude continues dumping into the western US as has been a running theme for the past month plus.

Although the MJO wheeler plots are showing a phase 1 MJO, they have actually shown the MJO moving “backwards” over recent days…a likely explanation for this is that the MJO signals were picking up on tropical-cyclone Evan over the southwestern Pacific Ocean:

post-525-0-78914900-1355814205_thumb.png

Thus, I’m not expecting the current “Phase 1” MJO to help relax the –PNA. Given there is a large area of convection and vertical lift over the Indian Ocean, continued strong central Pacific ridging for the foreseeable future seems reasonable:

post-525-0-19021000-1355814246_thumb.gif

The GFS forecasted upper level jet orientation over the Pacific over the coming days jives with this, with a stronger sub-tropical jet over eastern Asia into the western Pacific north of the convection, breaking in the western Pacific and supporting storminess up into extreme NE Asia, and higher heights, as progged, over the Bering Sea and even towards Alaska.

So, long story short, I’m expecting the –PNA pattern to continue over the foreseeable future. This means we can continue to expect troughing near the west coast of the US and Canada with lots of storms moving east as we head forward.

WRT blocking over Canada…there is strong model consensus for blocking continuing over central and eastern Canada for at least the next ten days…which will limit how far NW any storms coming out of the western US can hook once they get wound up…

post-525-0-87135200-1355814279_thumb.gif

Given that this upcoming storm system for the second half of this week should progress to near the 50/50 position by Christmas, the next wave coming out of the west…strongly agreed upon by guidance to occur around Christmas…should have room to amplify over the lower Plains, assuming the next shortwave behind it does not come in too quickly.

post-525-0-75225700-1355814321_thumb.png

The European ensembles show more spacing between the next shortwave diving towards the NW US than the 0z GFS ensembles show, and as a result show a slightly more coherent and farther NW tracking storm in the means in the days past Christmas…however, due to the blocking over central and eastern Canada, keep the low farther south towards the lower Ohio Valley/TN Valley before transferring to the east coast. The GFS ensembles do show some hint at a storm in the means, although spacing between the potential post-Christmas storm spawning shortwave and next incoming wave is close to being an issue on the GFS suite.

In short, the pattern supports another potential storm across portions of the lower lakes and Ohio Valley, as well as the central Mississippi Valley due to an expected farther south storm track. Given the blocky nature of the pattern over the eastern half of N. America, this system may be a slow mover and this will be one to watch for.

Beyond next week, uncertainty increases a bit…

As shown above, it appears as though the MJO will remain weak with convection remaining in the Indian Ocean into early January…this supports a continued –PNA pattern…however, there is divergence in the handling of a potential renewed vortex off of the Siberia coast and central Pacific ridging beginning to appear on the ensembles by day 10:

post-525-0-43950300-1355814413_thumb.png

The GFS ensembles on the left are a bit deeper with the renewed vortex and thus more amplified with ridging into the Alaska region, while the European ensembles are trying to beat down the ridging and blast the CONUS with an un-impeded Pacific jet as we head towards the New Year. Given the discussed expectation of convection remain west of the dateline for the foreseeable, resulting in a continued strong Asian sub-tropical jet breaking over the western Pacific, I’m going to go with persistence and lean towards the GFS suite idea of maintaining more ridging into the GOA as we head towards the end of December, continuing to dump energy into the western coast of N. America.

Here’s the persistence I’m referring to:

post-525-0-31042600-1355814448_thumb.png

Thus, we should see the pattern remain quite active through the end of December with a –PNA persisting and troughing being centered over the western US.

This will become interesting as we see how the –NAO/AO play out…the barrage of troughs over the central US over recent days and through the rest of this week is pumping up heights over central/eastern Canada and resulting in a west based –NAO, which is going to try to suppress things a bit heading into next week. Thanks to continued energy coming out of the west, we are slowly beating down the eastern US ridging by this weekend as cold is slowly brought south.

However, a –PNA often does not co-exist with a west based –NAO as it generally promotes eastern US ridging. Given we may see the pattern become suppressed and see troughs come out flatter and pump up heights less over Canada and into Greenland, we may see the –NAO slowly weaken by the end of January. The GFS ensemble NAO/AO forecasts agree with this assessment:

post-525-0-02486900-1355814496_thumb.png

Thus, in general, over the next two weeks, I’m thinking:

-Late week winter storm moves east and becomes a 50/50 low early next week.

-This, combined with a west based –NAO and –AO should result in the next wave ejecting around Christmas Eve to stay farther south, but there should be enough space between it and the 50/50 low for it to amplify.

-Assuming shortwaves over the west aren’t too close together early next week, the wave ejecting on Monday could spawn a strong system Tuesday-Wednesday that favors potential significant snows/ice for the central Plains, central Mississippi Valley, upper Ohio Valley and lower Lakes and then east towards the Mid-Atlantic and New England.

-After this shortwave, there may be another chance for accumulating snows over the southern/eastern portions of our sub-forum with the next wave around Saturday the 30th, assuming a GEFS type evolution occurs and the Pacific pattern remains a bit more amplified as I argued for above.

-After this system, we should see the pattern slowly moderate as we head towards January 1 due to a continued –PNA and likely relaxation of central/eastern Canada blocking.

Looking at the first half of January:

post-525-0-28689900-1355814542_thumb.png

The CFS, along with the ECM Ensemble wheeler plot posted much farther up, are showing the current convection in the Indian Ocean propagating east as we head towards January 1, which would result in the Pacific jet breaking south of Alaska, and promoting storminess into that region. This would result in a +EPO/WPO and cold in the Bering Sea and Alaska and warmth over the central/eastern US if this type of MJO evolution occurred.

post-525-0-51135400-1355814576_thumb.gif

The GFS ensembles both appear to show the EPO/WPO both going positive near the beginning of January, which would support widespread warmth over the central/eastern CONUS, per the positive phase composites of both those indices available at the PSD map room website…

post-525-0-02637300-1355814609_thumb.png

However, the CFS and EWP both show a new MJO wave developing in the Indian Ocean in early January and look poised to bring it east…so, we may see a more favorable MJO by mid-month.

When looking at the stratosphere…the stratospheric vortex has already been disrupted and shunned towards Eurasia, with bottom up warming occurring from northern Asia east towards northern N. America…and, the GFS and Euro are both showing another very pronounced warming centered over Eurasia after Christmas…this may really take out the stratospheric vortex for the second half of January and encourage robust high-latitude blocking:

post-525-0-61184000-1355814670_thumb.gif

So, when looking at the first half of January:

-I think the first week may feature a moderating trend and relaxation of the pattern. This may continue into the second week, don’t want to rush things like we tried doing in November when looking into December.

-Signs of a potentially more favorable MJO by mid-January support a potentially more + PNA after mid-January.

-Signs of a significant stratospheric warming event beginning after Christmas support potential robust high-latitude blocking after mid-January, allowing for a bit of a lag for things to work their way down.

-Much of Canada, especially western, and parts of the northern US remain snow covered and chilly, so the red carpet will be down for a potential major arctic blast if these factors align around mid-January.

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B-Rent

B-Rent

Posted
Posted

Somebody's eyes are perking up at IND

INTERESTING SCENARIO STARTING TO SHOW UP ON THE EXTENDED MODELS

JUST BEYOND THE FORECAST PERIOD...WITH A STORM SYSTEM POTENTIALLY

IMPACTING THE OHIO VALLEY BY THE MIDDLE OF NEXT WEEK. STRONG UPPER

LOW OFF THE PACIFIC NORTHWEST OVER THE WEEKEND WILL MOVE INTO THE

WESTERN PART OF THE COUNTRY AND AMPLIFY AS IT MOVES EAST ACROSS

THE COUNTRY MONDAY AND TUESDAY. BOTH THE ECMWF AND OP GFS HAVE THE

UPPER LOW DEEPENING AND BECOMING CUTOFF...PROMPTING THE

DEVELOPMENT AND STRENGTHENING OF A POTENTIALLY SIGNIFICANT STORM

SYSTEM THAT COULD AFFECT THE REGION. SEVERAL OF THE GFS ENSEMBLE

MEMBERS ARE ALSO PICKING UP ON THIS SYSTEM BY NEXT TUESDAY/

WEDNESDAY. AS WOULD BE EXPECTED AT 8-9 DAYS OUT...DIFFERENCES

EXIST ON SPECIFIC LOCATION...INTENSITY AND TIMING. AT THIS

POINT...WILL CONTINUE TO MONITOR MODEL TRENDS CLOSELY OVER THE

NEXT SEVERAL DAYS.

Would be nice to get this one to track closer to the river, should fill in the snow cover evenly then.

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