zwyts 8th consecutive winter outlook for DCA - 2011-12

[usedtobe]

We actually live in a hard place to predict temp anomalies. We are in a geographic location that is often caught between 2 regimes. Quite often we are not geographically far from reverse anomalies. It is even harder when you use a multiple-year sample to get an idea. So for example a month like February if we lived in Dixie it would be a no brainer to go heavy plus values, but where we live it honestly doesn't take a huge pattern difference to go from +2 to -2.

Exactly, even into the northeast, CPC usually puts them in equal chances as that region into our area has the least predictability. I think we may be the worst as in nina years it's typically warm across the south and could across the cnetral states with us being near the transition and during ninos, the northeast is warmer than normal and the southeast is colder which again puts us near the transition line. Same holds for a negative nao, we usually are colder than normal but the northeast towards maine is usually warmer than normal. I do think it likely that we end up with below normal precipitation as primary storm track probably will be to out north unless we get the northern stream to dig something so strongly it cuts off and goes to our south. Because of the qbo and solar aspect, I think this year is even tougher than most in terms or temps and snowfall. (whether we get close to normal or stay well below. Right now I favor the former over the latter but that may be wishful thinking. For some reason, I think we do better than last year but that's a WAG that cold change in the next month. Last year my snow guess worked out well but my temps were too warm overall as I underplayed the strength of the negative NAO.

[Bob Chill]

I do think it likely that we end up with below normal precipitation as primary storm track probably will be to out north unless we get the northern stream to dig something so strongly it cuts off and goes to our south.

Always appreciate your thoughts Wes. Hard to argue with a further N stormtrack.

What are your thoughts on Clippers? I would expect some periods of +PNA & -NAO this winter. The Nina doesn't look to be too strong and I think we will have some good EC troughing this year in response to both the low solar activity and also what I believe to be a potentially long term -AO/NAO cycle. PDO may be entering a long - stage too but I don't know enough about that to feel confident about talking about it.

If we have and active NS winter and we do have decent EC troughing we could potentially see a string of clippers that dig far enough south and cross through central VA right?

Of course the weenie in me is dying for miller A's but the odds of having good miller A's are stacked against us. I'm thinking one of the features that may in fact allow us to approach or even exceed normal snowfall this winter would be 3+ clippers in the 2-4" & 3-5" range.

[Deck Pic]

Always appreciate your thoughts Wes. Hard to argue with a further N stormtrack. What are your thoughts on Clippers? I would expect some periods of +PNA & -NAO this winter. The Nina doesn't look to be too strong and I think we will have some good EC troughing this year in response to both the low solar activity and also what I believe to be a potentially long term -AO/NAO cycle. PDO may be entering a long - stage too but I don't know enough about that to feel confident about talking about it. If we have and active NS winter and we do have decent EC troughing we could potentially see a string of clippers that dig far enough south and cross through central VA right?Of course the weenie in me is dying for miller A's but the odds of having good miller A's are stacked against us. I'm thinking one of the features that may in fact allow us to approach or even exceed normal snowfall this winter would be 3+ clippers in the 2-4" & 3-5" range.

Not speaking for Wes, but there will certainly be plenty of clippers with a strong northern stream. They always come with attendant problems though. Suppressed, too far north, lack of upper level support, moisture starved,robbed by the mountains, dry slotted by coastal low. We don't live in a great place for clippers. As you probably know we have to get really lucky to get 3"+ from one. I think the smart move for our area is to expect 1-2" at best unless as we get really close there is strong evidence to suggest otherwise.

[Bob Chill]

I agree zwts. The only time we get a nice shot from a clipper is when the 500mb low crosses central VA. Sometimes the early season clippers can get juiced up by the relatively warm atlantic.

I remember times in the 70 & 80's when clippers were more prolific snow producers. We had one in the mid 80's that bombed out overhead and brought thundersnow and 6" in just a couple of hours (can't remember the exact year).

We've been really unlucky with clippers the last 5-10 years. The mountains do their damage but it seems like the track has consistently been too far N to drop more than 2-3" and when they do track S of DCA the low isn't strong enough. I have a hunch that clippers track a bit further south this year.

Hopefully I'm right but it's more of a guess than anything else. My hunch is based solely on a weaker Nina and potential favorable -NAO and blocking

this year.

I put together some 500mb anamoly maps from the Nina years in the 60's but I can't find them. They had a nice look for us in the MA.

[usedtobe]

Not speaking for Wes, but there will certainly be plenty of clippers with a strong northern stream. They always come with attendant problems though. Suppressed, too far north, lack of upper level support, moisture starved,robbed by the mountains, dry slotted by coastal low. We don't live in a great place for clippers. As you probably know we have to get really lucky to get 3"+ from one. I think the smart move for our area is to expect 1-2" at best unless as we get really close there is strong evidence to suggest otherwise.

The only way we get more is if the upper vort is real strong, go sufficiently south of us to keep the surface low to our south and us in the deformation zone. Then occasionally, very occasionally, we can even get thunder snow if the temps are cold enough aloft. but even then, you usually only get around 4 inches because the systems more so fast.

Miller B are a different story and if an upper low closes of and moves slowly to our south, we can get a good snow like we got on Feb 10, 2010 but that's really unusual.

[BethesdaWX]

Why so few analogs? And why did you pick them over others? I'd think 1962-63 would be one you'd include based on the numerous similarities.

Second Year Nina or not adequate similarities seem somewhat important.

[H2O]

I agree zwts. The only time we get a nice shot from a clipper is when the 500mb low crosses central VA. Sometimes the early season clippers can get juiced up by the relatively warm atlantic.

I remember times in the 70 & 80's when clippers were more prolific snow producers. We had one in the mid 80's that bombed out overhead and brought thundersnow and 6" in just a couple of hours (can't remember the exact year).

We've been really unlucky with clippers the last 5-10 years. The mountains do their damage but it seems like the track has consistently been too far N to drop more than 2-3" and when they do track S of DCA the low isn't strong enough. I have a hunch that clippers track a bit further south this year.

Hopefully I'm right but it's more of a guess than anything else. My hunch is based solely on a weaker Nina and potential favorable -NAO and blocking

this year.

I put together some 500mb anamoly maps from the Nina years in the 60's but I can't find them. They had a nice look for us in the MA.

I think I recall this event but I thought it was more Miller B. I remember Bill Kamal(lol) taking about the low transferring off the coast and bombing and that is what helped cause the thundersnow.

[Deck Pic]

<b></b>Why so few analogs?  And why did you pick them over others?  I'd think 1962-63 would be one you'd include based on the numerous similarities. <b></b><b></b>Second Year Nina or not adequate similarities seem somewhat important.<b></b>

<b></b><b></b><b></b>

On an iPad and my post keeps getting deleted... Short answer is it was a cold summer. I can add more later.

[Deck Pic]

I think I recall this event but I thought it was more Miller B.  I remember Bill Kamal(lol) taking about the low transferring off the coast and bombing and that is what helped cause the thundersnow.

Youre taking about one of the march 1984 storms. Probably the 1st one.

[mitchnick]

Youre taking about one of the march 1984 storms. Probably the 1st one.

I was thinking the early March, 1984 storm

5"+ at BWI, 10"+ at PHL (maybe 12"+)

[mitchnick]

I was thinking the early March, 1984 storm

5"+ at BWI, 10"+ at PHL (maybe 12"+)

looks like it started the evening of 3/8/84

here's 3/8/84 at BWI

http://www.wunderground.com/history/airport/KBWI/1984/3/8/DailyHistory.html

[H2O]

We actually live in a hard place to predict temp anomalies. We are in a geographic location that is often caught between 2 regimes. Quite often we are not geographically far from reverse anomalies. It is even harder when you use a multiple-year sample to get an idea. So for example a month like February if we lived in Dixie it would be a no brainer to go heavy plus values, but where we live it honestly doesn't take a huge pattern difference to go from +2 to -2.

Agreed and it can also be said that the same applies to storms around here. Or geography puts us in the no man's land between the polar jet and STJ. We need both to work together or we end up with messes and misses.

[BethesdaWX]

<b></b><b></b><b></b>

On an iPad and my post keeps getting deleted... Short answer is it was a cold summer. I can add more later.

Ok all good, was definitely a cooler summer, though I think that relates back to the NAO thing, Sun activity was worlds higher in 1962 than it is now so perhaps deciphering between what forces the -NAO may help out. Aside from the solar thing the QBO phase can determine the strength & basis of whatever the NAO phase we may be in, and at the moment the QBO in the lower levels is heavily positive while the upper levels are looking quite negative.

50mb + & 30mb - is troubling, I can't find a weak-solar -PDO 2nd yr La Nina featuring a +QBO in the lower levels & a -QBO in the upper levels, could be a very good thing for brief (progressive) cold periods, but potential for miller-A type storm tracks with the proper phasing if the MJO is in the right phase.

I'm making some assumptions here but who knows it might end up telling us something later on.

[ORH_wxman]

The only way we get more is if the upper vort is real strong, go sufficiently south of us to keep the surface low to our south and us in the deformation zone. Then occasionally, very occasionally, we can even get thunder snow if the temps are cold enough aloft. but even then, you usually only get around 4 inches because the systems more so fast.

Miller B are a different story and if an upper low closes of and moves slowly to our south, we can get a good snow like we got on Feb 10, 2010 but that's really unusual.

I recall 12/5/07 being an ideal clipper for DC. I think some of the northern suburbs got 5"+, while 2-4" fell over the city.

[Bob Chill]

looks like it started the evening of 3/8/84

here's 3/8/84 at BWI

http://www.wundergro...ilyHistory.html

I've been digging around and this is probably right. I can't quite place the year in my mind. It has to be between 1980 & 1985 because I didn't have my driver's license yet and it happened in the last house I lived in with my folks. If this is the only +SN with thunder event during that time then that was it. Time of day looks right too. It happened late afternoon and brought traffic to its knees.

[mitchnick]

I've been digging around and this is probably right. I can't quite place the year in my mind. It has to be between 1980 & 1985 because I didn't have my driver's license yet and it happened in the last house I lived in with my folks. If this is the only +SN with thunder event during that time then that was it. Time of day looks right too. It happened late afternoon and brought traffic to its knees.

yep, that's correct

I drove down to my friend's house in Old Town that evening and almost crashed on 295 near BWI

it was an over performer at BWI N & E for sure, but not much at DCA at all

I think Old Town had 1/2-1"; I recall thinking how pissed I would have been if I lived there, but actually was cursing the snow on the way down in my 77' Pinto w/near bald tires

[aldie 22]

I've always been able to handle the "normal" type winters while waiting for the blowup winters we get around here every 7 years or so...it's the stinky less than 10" winters that are hard to swallow for me....hopefully this one falls in the 15-20" range with plenty of cold and some snow cover...looks like I will be traveling to Cleveland a lot this year based on some of the outlooks to get my big snow...I'm ok with that.

[Deck Pic]

I've always been able to handle the "normal" type winters while waiting for the blowup winters we get around here every 7 years or so...it's the stinky less than 10" winters that are hard to swallow for me....hopefully this one falls in the 15-20" range with plenty of cold and some snow cover...looks like I will be traveling to Cleveland a lot this year based on some of the outlooks to get my big snow...I'm ok with that.

We will have opportunities. If we get 9-10 bites at the apple like we did last year it is hard to think we won't back into at least one decent (4"+) event that is northern stream dominant and not the perfect setup addition to an event or 2 with a better setup and more potential. I just think we have to have measured expectations with the state of PAC. This could be the year we break the boom/bust drought and have an old school winter where DCA gets 20" and IAD gets 30" but I would bet against it. I'd say there is a 75% chance we go at or below normal at the airports.

[SNO]

We will have opportunities. If we get 9-10 bites at the apple like we did last year it is hard to think we won't back into at least one decent (4"+) event that is northern stream dominant and not the perfect setup addition to an event or 2 with a better setup and more potential. I just think we have to have measured expectations with the state of PAC. This could be the year we break the boom/bust drought and have an old school winter where DCA gets 20" and IAD gets 30" but I would bet against it. I'd say there is a 75% chance we go at or below normal at the airports.

zwyts - I agree with you that this winter has the makings of "an old school winter". As I stated before, areas N and W of DC will be the winners this winter. Areas S & E will suffer with "mixing" events. I have high confidence IAD will have at least 30" with winter. IAD will certainly win the snow totals over DCA and BWI this winter...LOCK OF THE WINTER!!!

[BethesdaWX]

zwyts - I agree with you that this winter has the makings of "an old school winter". As I stated before, areas N and W of DC will be the winners this winter. Areas S & E will suffer with "mixing" events. I have high confidence IAD will have at least 30" with winter. IAD will certainly win the snow totals over DCA and BWI this winter...LOCK OF THE WINTER!!!

what about me? how much for mby?

[easternsnowman]

zwyts - I agree with you that this winter has the makings of "an old school winter". As I stated before, areas N and W of DC will be the winners this winter. Areas S & E will suffer with "mixing" events. I have high confidence IAD will have at least 30" with winter. IAD will certainly win the snow totals over DCA and BWI this winter...LOCK OF THE WINTER!!!

That's my thinking too. I believe Dc and BWI will be around normal but the burbs will do much better. Last year I felt south of the M/D line was in trouble, but this year will be better for you guys.

[Ji]

I've always been able to handle the "normal" type winters while waiting for the blowup winters we get around here every 7 years or so...it's the stinky less than 10" winters that are hard to swallow for me....hopefully this one falls in the 15-20" range with plenty of cold and some snow cover...looks like I will be traveling to Cleveland a lot this year based on some of the outlooks to get my big

snow...I'm ok with that.

It's not the same when you have to borrow other people snow

[Deck Pic]

zwyts - I agree with you that this winter has the makings of "an old school winter". As I stated before, areas N and W of DC will be the winners this winter. Areas S & E will suffer with "mixing" events. I have high confidence IAD will have at least 30" with winter. IAD will certainly win the snow totals over DCA and BWI this winter...LOCK OF THE WINTER!!!

could happen but I would favor BWI as being most likely to do best versus normal.....better latitude/longitude for miller B's, grazing coastals....I don't anticipate a prevalent storm track that favors IAD for the bulk of winter, but decent early/late season events definitely favor them over the other airports....I think the 12/15 to 2/29 period favors BWI and I think they get more snow than IAD this winter....If IAD ends up with more snow, I bet it is because of events in NOV/Early DEC and March/April

[Bob Chill]

could happen but I would favor BWI as being most likely to do best versus normal.....better latitude/longitude for miller B's, grazing coastals....I don't anticipate a prevalent storm track that favors IAD for the bulk of winter, but decent early/late season events definitely favor them over the other airports....I think the 12/15 to 2/29 period favors BWI and I think they get more snow than IAD this winter....If IAD ends up with more snow, I bet it is because of events in NOV/Early DEC and March/April

I agree zwts. Miller B's and IAD don't get along that well. However, we just missed multiple NS and SS vorts phasing last year. I do think we'll benefit from some phasers this year I believe we'll have the opportunity for some good front end thumps from Miller B's before the screwzone W of I-95 and the weenie in me thinks a classic miller A is on the table.

IMO- The only way IAD beats BWI this year is if BWI suffers from mixing while IAD stays all white.

Another thing that I've been thinking about is ice. With a NS dominated winter, there will be storms that run the apps or into the OV. We may have more ice events than the last couple of years.

[Deck Pic]

I agree zwts. Miller B's and IAD don't get along that well. However, we just missed multiple NS and SS vorts phasing last year. I do think we'll benefit from some phasers this year I believe we'll have the opportunity for some good front end thumps from Miller B's before the screwzone W of I-95 and the weenie in me thinks a classic miller A is on the table.

IMO- The only way IAD beats BWI this year is if BWI suffers from mixing while IAD stays all white.

Another thing that I've been thinking about is ice. With a NS dominated winter, there will be storms that run the apps or into the OV. We may have more ice events than the last couple of years.

I think we will have to rely on the fact that climo is such that a percentage of our snow over time comes from nontraditional and imperfect setups, thus they do happen....I don't think it is unreasonable to believe we will score a 4"+ event that is flukey or "lucky" or convoluted...In fact I would lean towards it....If we get really lucky it is a 1/25/00 or 3/9/99 or 12/31/70....but even a 12/5/07 event would be a nice bonus....I don't agree about the classic miller A unless it is an early or late season event that is probably mixy.....I would lean more toward our biggest event being a miller B/hybrid during a good period of blocking or a storm like 3/2/09 or January of this year that is driven by the upper levels....I think a big southern stream, moisture laden miller A is unlikely

My best guess is our 2 biggest snows come from a miller B that hits us but hits 40N much better and then something a little more convoluted that just works out (i.e. overperforming clipper, ULL driven miller A/hybrid)

[Bob Chill]

My best guess is our 2 biggest snows come from a miller B that hits us but hits 40N much better and then something a little more convoluted that just works out (i.e. overperforming clipper, ULL driven miller A/hybrid)

Pretty good guess IMO. We could get lucky in an amplified pattern too. Our biggest snow(s) could easily come from a 500mb vort(s) rounding the base of the EC trough and putting us in the jackpot as the energy slides off the coast. We got close to this a couple of times last year when the SE and VA tidewater cashed in pretty good. Sometimes too strong of a -NAO is not a good thing for us.