Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

December 2012 Pattern Analysis


HailMan06

Recommended Posts

The vortex is obviously not in a good position, but it's in a much better position than it was last year and is being moved around a lot, as opposed to being stagnant in the worst possible spot.

Our cold air mass will be a bit stale, yes, but provided we get a northerly flow and precipitation from a storm to our south, then most locations should be fine.

Link to comment
Share on other sites

  • Replies 610
  • Created
  • Last Reply

Also looks like the ideas posted earlier of the 2nd storm having a hard time to cut are coming true on some of the latest guidance. The Euro ensembles are still relatively amped but it's definitely a different look from previous runs.

Once again, a rolling, flat ridge upstream of our storm combined with strong positive height anomalies to our north means that a storm is going to have a very hard time cutting.

Link to comment
Share on other sites

DGEX just came in with a 976mb low near the Virginia Capes at 186 hrs that slides east and out to sea, with a precip shield further north that absolutely nails from Trenton east to Asbury Park and south with 1.00-2.5 inches of precip. 850's are below freezing but 850's are too warm, taken verbatim. Snowfall map shows from 4-10 inches from Trenton down to Southwest New Jersey and Philadelphia, and a foot down by Richmond, VA.

JMA also has a 993mb low with lots of moisture in nearly the identical position at 192 hours.

Control run of the Euro has a 976 mb near the southern DelMarva at 198 hrs that absolutely nails our area with around 1.5 inches of precip.

And below is the 12z European Ensemble Mean

post-1914-0-24382500-1355266417_thumb.gi

Link to comment
Share on other sites

It's not a dominant Alaskan vortex because its north of Alaska and that makes a huge difference. Plus it's not inducing a torch...and it's not in a similar position to last year nor is it similar to last year...so what's your point then? Your initial post means nothing?

The PV also splits into NE Pacific trough, that pump up heights over West Coast somewhat, with the -NAO block.

Link to comment
Share on other sites

It's not a dominant Alaskan vortex because its north of Alaska and that makes a huge difference. Plus it's not inducing a torch...and it's not in a similar position to last year nor is it similar to last year...so what's your point then? Your initial post means nothing?

Is not inducing a torch because of the west based NAO. If this is weaker than proged we torch plain and simple. While the core of the vortex is North of AK its sphere of low heights covers all of AK despite what you are claiming it's not worlds different than last year

Link to comment
Share on other sites

Is not inducing a torch because of the west based NAO. If this is weaker than proged we torch plain and simple. While the core of the vortex is North of AK its sphere of low heights covers all of AK despite what you are claiming it's not worlds different than last year

You do realize it's actually helping the west based NAO, right? Part of the reason why the west based NAO is happening is because of the height rise downstream of that PV.

Link to comment
Share on other sites

Is not inducing a torch because of the west based NAO. If this is weaker than proged we torch plain and simple. While the core of the vortex is North of AK its sphere of low heights covers all of AK despite what you are claiming it's not worlds different than last year

It is helping to pump up the West Based NAO ridge, man. Also, it is not there until the end of the run on every model despite what you might be hallucinating. I just don't understand why you would bump the post when your original post was wrong. You said that a dominant AK vortex was coming back similar to last year. That is 100% incorrect. It's not that complicated.

Link to comment
Share on other sites

^ That looks a lot like 12/19/2009. Or at least how the models initially showed that storm.

You know I was thinking that earlier. 12/19/09 was less amplified with the vort that came through the MS Valley though...so if the models are to be believed things could get very interesting especially if that weird psuedo 50/50 starts retrograding in SE Canada like the GFS advertises. Here's 12/19/09 for comparison. A lot more northern stream energy sitting over Southeast Canada.

121918.png

Link to comment
Share on other sites

I think it's prudent to remain very cautious though, especially given the wild changes we're seeing on the models especially with the northern stream stuff. The GFS has zero continuity in that regard from run to run and those are things that will change the outcome of the storm dramatically.

The one good thing we can take away from this is that there's a fairly consistent signal for a vort coming out of the Pac NW and racing into the Central US and amplifying. Also worth noting that we need that first wave to get through like the guidance shows and usher in some cold air -- but if its too strong it could sweep the baroclinic zone east with it. We'll see.

Link to comment
Share on other sites

I think it's prudent to remain very cautious though, especially given the wild changes we're seeing on the models especially with the northern stream stuff. The GFS has zero continuity in that regard from run to run and those are things that will change the outcome of the storm dramatically.

The one good thing we can take away from this is that there's a fairly consistent signal for a vort coming out of the Pac NW and racing into the Central US and amplifying. Also worth noting that we need that first wave to get through like the guidance shows and usher in some cold air -- but if its too strong it could sweep the baroclinic zone east with it. We'll see.

There are lots of small nuances and ebbs in the flow, but once that block truly becomes established, the margin for error in us getting a snowstorm increases. The PAC is a bit poor so it would be nice to see a trend for some height rises upstream of our storm.

Link to comment
Share on other sites

You know I was thinking that earlier. 12/19/09 was less amplified with the vort that came through the MS Valley though...so if the models are to be believed things could get very interesting especially if that weird psuedo 50/50 starts retrograding in SE Canada like the GFS advertises. Here's 12/19/09 for comparison. A lot more northern stream energy sitting over Southeast Canada.

121918.png

In the immortal words of that famous freedom fighter mel gibson. Hold Hoooold Hoooooold

Link to comment
Share on other sites

December 19th-20th has seen it's share of significant snowfalls recently and in the past...Four times there were storms with over 8" of snow on the 19-20th...

1948 had 16.0"

1945 had 8.3"

1995 had 7.7"

2009 had 10.9"

2008 had 4.0"

The date with the most major storms is December 26th-27th...

1872 had 18"

1933 had 11"

1947 had 26"

2010 had 20"

1890 had 7"

December 5th-6th is the other dates with more than three major storms...

1886 had 8"

1926 had 8"

2002 had 6"

2003 had 14"...

Link to comment
Share on other sites

This is all goin to depend on how fast sun mon system gets off the field. The models see the block they to some degree see the ridge.

If the first system are too close u flatten the flow and ots u go. The signal is there. Lets get them seperated and we r in biz.

Link to comment
Share on other sites

You know I was thinking that earlier. 12/19/09 was less amplified with the vort that came through the MS Valley though...so if the models are to be believed things could get very interesting especially if that weird psuedo 50/50 starts retrograding in SE Canada like the GFS advertises. Here's 12/19/09 for comparison. A lot more northern stream energy sitting over Southeast Canada.

121918.png

I feel like it's similar with regards to the heights being "relatively" high in the east coast considering there's a trough there, with relatively spaced out height contours, which allows for slow, gradual, but steady amplification. Also with the retrograded 50/50 low piece to the north of the trough. I remember initially with that storm, the models had that retrograded 50/50 piece just to the north of the trough, kinda like what the 18z GFS OP was showing. The degree of blocking is of course similar, too.

That storm had a better PAC pattern, though.

121821.png

Link to comment
Share on other sites

Run to run differences in the H5 setup on the GFS are almost laughable; it clearly doesn't have a good handle on the medium range, or even starting from about 60 hours out. Nice looking strong coastal storm this run with snow inland but I wouldn't take what it shows seriously until it starts to get a better handle on things.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...