The Winter 2010-11 NYC/PHL Medium Range Thread

[Thunder Road]

per 18Z GFS at KPNE, the event at hr 300 could be some ice/snow.

850mb temps only get to 1 C, and the surface is around freezing at that time.

FCST

HourValid

TimeMax

TempMin

TempTd10m

Wind mph850mb

Wind mphTotal

Precip(")Conv.

Precip(")500-1000

THKNS500mb

Height850mb

Temp °C500mb

Temp °CMSLP

mbTotal

Cloud Cover 300 Sat 12/11 06Z 32 ° 26 ° 31 ° SE 9 SSW 40 0.01 0.00 540 5590 ° -20 °1025 88 % 312 Sat 12/11 18Z 34 ° 28 ° 33 ° S 7 SW 47 0.48 0.00 541 5531 ° -21 °1014 100 % 324 Sun 12/12 06Z 35 ° 32 ° 34 ° WNW 7 W 20 0.17 0.00 535 545-5 ° -22 °1011 85 %

I really just posted this because it looked cool pasted in here, and not to analyze a storm at hr 312...

Edit: arrrrrrrrrrrgh it didn't work

well anyway, check here: http://wxweb.meteostar.com/sample/sample.shtml?text=kpne

[Chris L]

Don't freak out about the GFS...

[tombo82685]

18z GFS ensemble mean shows a low near the coast. Getting there.

lol since when is a 998 low major? Last yr we would of laughed at that

[SnoSki14]

The gfs looks good up to Day 10 then falls apart after Day 10 once again. I would be amazed if we got another early December storm but there are several factors that support it. The pattern isn't going to get much better than the next 2-3 weeks this season, so I hope we get something going.

[MJO812]

lol since when is a 998 low major? Last yr we would of laughed at that

It's a start.

[daxx]

No storm right now on gfs is fine by me. It is better than showing a secs right now, and then it not happening at all. So many times in the past the gfs has raised everyones hopes on one run, only to be let down on another.

[Alpha5]

lol since when is a 998 low major? Last yr we would of laughed at that

1) Last year was an extreme anomaly and we had an STJ on roids

2) The ensembles look much better than the OP GFS, even though they have the storm offshore

[am19psu]

So I'm back from vacation and just diving back into everything. It's amazing to me how much the AO/NAO is dominating all the forecasts over all the other forcings.

I'm not breaking new ground here, because HM is already talking about it in the main thread, but after the storm threat on the 8th-9th, there is going to be some strong warming across the Eastern U.S. with the MJO moving into P4/P5.

Tropical Convection Hovmoller

[am19psu]

It will be interesting to see if the MJO can swing around to P7/P8 by Christmas time. If that happens, JB might just be right about a White Christmas.

[Rainshadow]

So I'm back from vacation and just diving back into everything. It's amazing to me how much the AO/NAO is dominating all the forecasts over all the other forcings.

I'm not breaking new ground here, because HM is already talking about it in the main thread, but after the storm threat on the 8th-9th, there is going to be some strong warming across the Eastern U.S. with the MJO moving into P4/P5.

Tropical Convection Hovmoller

Nice charts, if its possible what link did you get those climo composites?

[am19psu]

Nice charts, if its possible what link did you get those climo composites?

MJO Temperature Composites

MJO Precip Composites

[Rainshadow]

MJO Temperature Composites

MJO Precip Composites

Thanks. A better read even if its a three month composite vs the cdc site.

[Rainshadow]

I know you meant this for beyond day 7(?), didn't know where else to post this and if this applies to the short term, the longer term

I know there are outlook periods where we (well we go out 7 days) have to forecast something, but I suspect that overall medium/long range forecast skill is going to return to its normal level if not slightly lower than normal level of uncertainty this winter vs last winter where it seems like model skill excelled. I saw some pretty bad solutions (Euro too) even 4 days in advance this autumn. I personally am not going to be putting much confidence in any model solution until we're within 5 days maybe even within 4 days. This cuts both ways Jan 2000 and March 2009 (both ninas or a nina and near nina) were expected to be dry a couple of days away and we saw what occurred there.

[am19psu]

I know you meant this for beyond day 7(?), didn't know where else to post this and if this applies to the short term, the longer term

I know there are outlook periods where we (well we go out 7 days) have to forecast something, but I suspect that overall medium/long range forecast skill is going to return to its normal level if not slightly lower than normal level of uncertainty this winter vs last winter where it seems like model skill excelled. I saw some pretty bad solutions (Euro too) even 4 days in advance this autumn. I personally am not going to be putting much confidence in any model solution until we're within 5 days maybe even within 4 days. This cuts both ways Jan 2000 and March 2009 (both ninas or a nina and near nina) were expected to be dry a couple of days away and we saw what occurred there.

I'm just getting into this stuff for the first time, but isn't lower predictability common in Ninas vs. Ninos?

The big thing I've been trying to get a handle on are the tropics (where I think I am pretty good) and the mountains/AAM (not so much) to derive medium range forecasts, instead of using the models beyond the first week. I'm sure I'm going to bust miserably a lot this year, but hopefully in a few years I can be at your, Wes', Gibbs', HM's, etc. levels

[am19psu]

FWIW, I'm still thinking warmth after Dec 10-11 based on the MJO projections. This will be the first good MJO pulse since early October and ought to dominate the pattern. Expect a ripping Pac jet/+EPO to dominate the pattern in mid-month, though that would actually cause the core of the warmth to occur farther west over the OH Valley/Lakes.

[A-L-E-X]

FWIW, I'm still thinking warmth after Dec 10-11 based on the MJO projections. This will be the first good MJO pulse since early October and ought to dominate the pattern. Expect a ripping Pac jet/+EPO to dominate the pattern in mid-month, though that would actually cause the core of the warmth to occur farther west over the OH Valley/Lakes.

What do you see happening in western europe?  Continued cold and snow?  And do you think our pattern flips back to cold towards the latter part of December?

[am19psu]

What do you see happening in western europe? Continued cold and snow? And do you think our pattern flips back to cold towards the latter part of December?

That's definitely outside my realm of expertise, but I'd guess the block moves eastward and the cold/snow pummels Eastern Europe mid-month.

Late in the month, it really depends if the MJO can progress around to P7/P8. It's less likely because of the La Nina, but it happened back in early November. If it does get there, we could see a White Christmas. Personally, I'd lean toward Nina climo, though.

[A-L-E-X]

That's definitely outside my realm of expertise, but I'd guess the block moves eastward and the cold/snow pummels Eastern Europe mid-month.

Late in the month, it really depends if the MJO can progress around to P7/P8. It's less likely because of the La Nina, but it happened back in early November. If it does get there, we could see a White Christmas. Personally, I'd lean toward Nina climo, though.

Id tend to agree-- in most la nina's, once the pattern switches back to mild, stay mild for a while.  Hell, we had this even in the much touted snowy weak la ninas of 1966-67 and 1995-96 which torched in January after the big snowfalls.  The big question then becomes, will we trend back to colder and snowier in February and March like those la ninas did (and a few others.)

BTW the block moving eastward-- sounds like our next period of neg nao might be an east-based one then.

[CoastalWx]

Id tend to agree-- in most la nina's, once the pattern switches back to mild, stay mild for a while. Hell, we had this even in the much touted snowy weak la ninas of 1966-67 and 1995-96 which torched in January after the big snowfalls. The big question then becomes, will we trend back to colder and snowier in February and March like those la ninas did (and a few others.)

BTW the block moving eastward-- sounds like our next period of neg nao might be an east-based one then.

It's possible there may be a few milder days near mid month, but I'm not sold on that at all. The -NAO block comes back almost to where it is right now and troughing redevelops in the east. Now the MJO forcing might try and fight this, but as of now...gotta respect the -nao block. It will be interesting to see how this plays out.

[am19psu]

It's possible there may be a few milder days near mid month, but I'm not sold on that at all. The -NAO block comes back almost to where it is right now and troughing redevelops in the east. Now the MJO forcing might try and fight this, but as of now...gotta respect the -nao block. It will be interesting to see how this plays out.

No argument from me there. I'm banking on the Pacific ruling the Atlantic, but if the Greenland block stays in place, we could still end up cold again right after the 11th.

[nynjpaweather]

So I'm back from vacation and just diving back into everything. It's amazing to me how much the AO/NAO is dominating all the forecasts over all the other forcings.

I'm not breaking new ground here, because HM is already talking about it in the main thread, but after the storm threat on the 8th-9th, there is going to be some strong warming across the Eastern U.S. with the MJO moving into P4/P5.

Tropical Convection Hovmoller

Just a quick point on the MJO. Not all models for the MJO phases agree with what you have up here, (http://www.cpc.noaa....clivar_wh.shtml)

Further, I think the forcing of the AO and NOA, which I strongly believe is connected to the latest solar developments and the location of stratospheric temperature anomalies, is not going away any time soon. I would caution against a significant warm up for the entire United States. Perhaps a moderation to near normal and above normal for Texas on through the Southeast, but I think the block over Greenland holds and does not collapse.

Tropical forcing and the MJO IS important, but it is not the only influence on the atmosphere, especially this winter. At any rate, should be an interesting 60 days to see how everything works out.

[MJO812]

It's possible there may be a few milder days near mid month, but I'm not sold on that at all. The -NAO block comes back almost to where it is right now and troughing redevelops in the east. Now the MJO forcing might try and fight this, but as of now...gotta respect the -nao block. It will be interesting to see how this plays out.

That's what the Euro does. The -NAO block redevelops after a brief moderation. This -NAO doesn't seem like it wants to go away anytime soon.

[am19psu]

Just a quick point on the MJO. Not all models for the MJO phases agree with what you have up here, (http://www.cpc.noaa....clivar_wh.shtml)

I wouldn't trust anything other than the Euro and UKM models for the MJO forecast. None of the other models have ever shown skill at MJO prediction.

I agree with everything else you wrote about the NAO/solar stuff.

[A-L-E-X]

I wouldn't trust anything other than the Euro and UKM models for the MJO forecast. None of the other models have ever shown skill at MJO prediction.

I agree with everything else you wrote about the NAO/solar stuff.

Overall it does seem like a neg nao winter (predominantly.)  I do agree that in the "heart" of the La Nina (which is typically January) we will probably be mild, but I think December and February are still open to the nao winning the tug of war with enso.

[nynjpaweather]

I wouldn't trust anything other than the Euro and UKM models for the MJO forecast. None of the other models have ever shown skill at MJO prediction.

I agree with everything else you wrote about the NAO/solar stuff.

Understandable, however the Euro/UKM has not exactly been the standard reliable self so far this Fall/Winter, which is why I'm a bit hesitant to jump on boarder with the MJO forecast.

[CoastalWx]

No argument from me there. I'm banking on the Pacific ruling the Atlantic, but if the Greenland block stays in place, we could still end up cold again right after the 11th.

Yeah, I mean obviously you guys may walk the line a little more, but it's crazy how the block just wants to stay. Some of the models want a Miller B around the 13th, but it also could be a southwest flow event.....basically a OH valley runner.

[CoastalWx]

Just a quick point on the MJO. Not all models for the MJO phases agree with what you have up here, (http://www.cpc.noaa....clivar_wh.shtml)

Further, I think the forcing of the AO and NOA, which I strongly believe is connected to the latest solar developments and the location of stratospheric temperature anomalies, is not going away any time soon. I would caution against a significant warm up for the entire United States. Perhaps a moderation to near normal and above normal for Texas on through the Southeast, but I think the block over Greenland holds and does not collapse.

Tropical forcing and the MJO IS important, but it is not the only influence on the atmosphere, especially this winter. At any rate, should be an interesting 60 days to see how everything works out.

Steve, what are the latest solar developments that you are talking about?

[A-L-E-X]

Yeah, I mean obviously you guys may walk the line a little more, but it's crazy how the block just wants to stay. Some of the models want a Miller B around the 13th, but it also could be a southwest flow event.....basically a OH valley runner.

Maybe there is some sort of ao/nao "muscle memory" from last winter-- and the nina after a nino thing could have some weight also.

[nynjpaweather]

Steve, what are the latest solar developments that you are talking about?

The overall impacts of Extreme Ultraviolet Radiation on the thermosphere and resulting impacts on location of warm anomalies in the stratosphere. The evolution of this has been growing since early Summer and continues today.

[CoastalWx]

The overall impacts of Extreme Ultraviolet Radiation on the thermosphere and resulting impacts on location of warm anomalies in the stratosphere. The evolution of this has been growing since early Summer and continues today.

I wasn't aware that ultraviolet radiation was that intense currently. I assume this is from the increase in solar activity? It seems like there are a plethora of solar arguments..so just trying to make sense out of them.