December and a Hint of January Pattern Discussion

[usedtobe]

I will be visiting good friends in Rehoboth beach, but wil still root for it

I'll be rooting for another .70 or so.  I measured earlier today on asphalt but found a better place so I'm now up to 1.4 for the year instead of 1.2.  You can root for Dave and Ji and laugh and H20 and me. 

[snow.]

I'll be rooting for another .70 or so.  I measured earlier today on asphalt but found a better place so I'm now up to 1.4 for the year instead of 1.2.  You can root for Dave and Ji and laugh and H20 and me. 

 

 

Wes, since I started measuring every event in 2004, I have surprisingly only missed one event  in 9 years.  And I have traveled here and there, though I guess it isn't hard to not miss an event in dc 

 

1/29-30/2005, I was out of town.  Not sure if you remember.  It was a weekend event.  Snow to zr/sleet and back to snow.  Your basic mangled DC mess.  I had someone measure for me and then tweaked based on surrounding reports.  2.5" in NW DC.  So that is what I am predicting for this upcoming weekend.  2.5" for Ian and Randy with a changeover and then back to snow at the end.

[usedtobe]

Wes, since I started measuring every event in 2004, I have surprisingly only missed one event  in 9 years.  And I have traveled here and there, though I guess it isn't hard to not miss an event in dc 

 

1/29-30/2005, I was out of town.  Not sure if you remember.  It was a weekend event.  Snow to zr/sleet and back to snow.  Your basic mangled DC mess.  I had someone measure for me and then tweaked based on surrounding reports.  2.5" in NW DC.  So that is what I am predicting for this upcoming weekend.  2.5" for Ian and Randy with a changeover and then back to snow at the end.

When I traveled for the NWS,  I missed alot of events but did pick up a 4 incher in Boulder and a foot storm in STL but I missed the 1983 blizzard,  the 2000 storm where I got like 17 inches in mby and a couple of 4 inchers.  Considering how few really big storms we get,  it seemed like I missed more than my share. 

[Bob Chill]

GFS and euro both agree on a more typical miller b now. Each day creeped in that direction. Pretty typical look. We have plenty of past examples on what to expect. Or range of possibilities. I probably don't need to add much today.

[snow.]

When I traveled for the NWS,  I missed alot of events but did pick up a 4 incher in Boulder and a foot storm in STL but I missed the 1983 blizzard,  the 2000 storm where I got like 17 inches in mby and a couple of 4 inchers.  Considering how few really big storms we get,  it seemed like I missed more than my share. 

 

All my years in DC, I only missed one biggie..1/25-26/87.  I was here for the 1st one.  When I got back, I only got as far as Wakefield Chapel rd via car.  And had to hoof it the rest of the way into my subdivision because the roads were impassable.

[WinterWxLuvr]

This is the thing. Models keep getting colder/better with each run. If this is a true CAD situation, then.....

And, as we all know, CAD often exceeds the model predictions.

[usedtobe]

All my years in DC, I only missed one biggie..1/25-26/87.  I was here for the 1st one.  When I got back, I only got as far as Wakefield Chapel rd via car.  And had to hoof it the rest of the way into my subdivision because the roads were impassable.

Those storms were two of my faves because I was on for both and for the second brought it farther north than the models did in the 36-60 hour time frame.  One of those successes you remember.  Course I also remember the heavy snow storm that ended up nice and sunny. 

[WxMan1]

Those storms were two of my faves because I was on for both and for the second brought it farther north than the models did in the 36-60 hour time frame.  One of those successes you remember.  Course I also remember the heavy snow storm that ended up nice and sunny. 

Wes, the twin nor'Easters in Jan 1987 were pure joy.  For someone who moved to the NoVa area during the summer of '83, and missed the Feb 11 1983 event, these were the kinds of event I had long waited for.  Three and a half years later, I got a taste of two such storms in 4 days.  The first one (Thu, 1/22) I measured about 11.0" at my house (West Springfield), the second one (Super Sunday into Sunday night, 1/25-26) was closer to a foot -- about 12-13 inches of what was a lower water content snowfall. Just a wonderful time!

 

I do seem to recall a storm that never materialized in Jan '86 -- actually it was around Super Bowl Sunday, or the following Monday when the Challenger exploded.  I think there were winter storm watches out -- I'm wondering if it ended up being a fish storm (?)

[usedtobe]

Wes, the twin nor'Easters in Jan 1987 were pure joy.  For someone who moved to the NoVa area during the summer of '83, and missed the Feb 11 1983 event, these were the kinds of event I had long waited for.  Three and a half years later, I got a taste of two such storms in 4 days.  The first one (Thu, 1/22) I measured about 11.0" at my house (West Springfield), the second one (Super Sunday into Sunday night, 1/25-26) was closer to a foot -- about 12-13 inches of what was a lower water content snowfall. Just a wonderful time!

 

I do seem to recall a storm that never materialized in Jan '86 -- actually it was around Super Bowl Sunday, or the following Monday when the Challenger exploded.  I think there were winter storm watches out -- I'm wondering if it ended up being a fish storm (?)

The storm I worked was later than that and Bruce Sullivan shared my fail.  I don't remember the date but am sure someone here does.  Both the 1987 events were with a nice negative AO and NAO.  On the second one, an older forecaster told me big storms just can't be that close together, it goes against nature.  He was a good snow forecaster everywhere but in DC because he hated snow. 

[WxMan1]

The storm I worked was later than that and Bruce Sullivan shared my fail.  I don't remember the date but am sure someone here does.  Both the 1987 events were with a nice negative AO and NAO.  On the second one, an older forecaster told me big storms just can't be that close together, it goes against nature.  He was a good snow forecaster everywhere but in DC because he hated snow. 

Classic!

[Harv_poor]

Wes, the twin nor'Easters in Jan 1987 were pure joy.  For someone who moved to the NoVa area during the summer of '83, and missed the Feb 11 1983 event, these were the kinds of event I had long waited for.  Three and a half years later, I got a taste of two such storms in 4 days.  The first one (Thu, 1/22) I measured about 11.0" at my house (West Springfield), the second one (Super Sunday into Sunday night, 1/25-26) was closer to a foot -- about 12-13 inches of what was a lower water content snowfall. Just a wonderful time!

 

I do seem to recall a storm that never materialized in Jan '86 -- actually it was around Super Bowl Sunday, or the following Monday when the Challenger exploded.  I think there were winter storm watches out -- I'm wondering if it ended up being a fish storm (?)

 

 

The 1986 storm was suppose to be on SB Sunday into the evening.. I remeber because we had just moved into our house two days earlier on the Friday.

 

Were the two 1987 storms imperfectly forcasted?  For some reason, I thought the first storm on Thursday was suppose to change to rain and it never did and there were lots of storires about people stuck in DC and on the roads. And for the second storm. I remember Bill Kamal on some private weatherline (Not the C&P telephone number) as being the first  to forcast the Sunday storm and wondering why the NWS had not posted Watches (or the equivalent back then). The second storm was a cold storm.  (The real reason I remember all this is I got to learn all about ice damming and by Tuesday morning I had water running thru three levels of my house destroying walls, ceilings, etc. What a nightmare!)

[gymengineer]

The 1986 storm was suppose to be on SB Sunday into the evening.. I remeber because we had just moved into our house two days earlier on the Friday.

Were the two 1987 storms imperfectly forcasted? For some reason, I thought the first storm on Thursday was suppose to change to rain and it never did and there were lots of storires about people stuck in DC and on the roads. And for the second storm. I remember Bill Kamal on some private weatherline (Not the C&P telephone number) as being the first to forcast the Sunday storm and wondering why the NWS had not posted Watches (or the equivalent back then). The second storm was a cold storm. (The real reason I remember all this is I got to learn all about ice damming and by Tuesday morning I had water running thru three levels of my house destroying walls, ceilings, etc. What a nightmare!)

You are right about the first storm- 1/22/87. It was forecast by many to be a snow with a quick change to rain scenario with the NWS forecast somewhere in the 1-3/2-4 range . Wes had a much better forecast at the HPC, if I'm remembering his posts correctly. This storm has been described as the ultimate "thread the needle" storm without the typical high in place for our 10" plus storms.

[Bob Chill]

Both the euro ens and gefs seem to agree about a warm spell before christmas. Basically the 20-24th range in general. GEFS is quite warm. +10 kinda warm. Euro ens not as much but the se ridge gets an opportunity to flex. 

 

Leading into and after Christmas looks like another invasion of really cold air. Kinda similar to the pattern we just had with a deep arctic airmass into TX and a gradient right over us. 

 

It's a long ways out but there is general agreement with a noticeable relaxation for a short period of time. 

 

One feature that seems to have a pretty strong signal is anomalous + heights in the GOA. This will keep the country from getting flooded with pac air so that is very good even if we get a se ridge invasion for a period. 

 

Southern stream does not appear to die down anytime soon. If anything it looks to continue through the entire month overall. For not having any good blocking in the atlantic, the pattern we are in and where it goes is about as good as you can get. 

 

Tune in tomorrow for a completely different look in the lr. 

[snowfan]

Cloudy and 35 on Christmas Day. Love the convenience of the 45-day accuwx forecasts. Really makes it easy to plan.

[midatlanticweather]

Cloudy and 35 on Christmas Day. Love the convenience of the 45-day accuwx forecasts. Really makes it easy to plan.

So accurate too - just like in thier name! Great tool!

[HighStakes]

You are right about the first storm- 1/22/87. It was forecast by many to be a snow with a quick change to rain scenario with the NWS forecast somewhere in the 1-3/2-4 range . Wes had a much better forecast at the HPC, if I'm remembering his posts correctly. This storm has been described as the ultimate "thread the needle" storm without the typical high in place for our 10" plus storms.

I remember it the same way. 1-3 2-4 then changing to rain was definitely the call for the Baltimore Metro. I think the original by most school systems were to open 2 hours late but that quickly changed to closed as forecasts rapidly deteriorated.

[HighStakes]

The 1986 storm was suppose to be on SB Sunday into the evening.. I remeber because we had just moved into our house two days earlier on the Friday.

 

Were the two 1987 storms imperfectly forcasted?  For some reason, I thought the first storm on Thursday was suppose to change to rain and it never did and there were lots of storires about people stuck in DC and on the roads. And for the second storm. I remember Bill Kamal on some private weatherline (Not the C&P telephone number) as being the first  to forcast the Sunday storm and wondering why the NWS had not posted Watches (or the equivalent back then). The second storm was a cold storm.  (The real reason I remember all this is I got to learn all about ice damming and by Tuesday morning I had water running thru three levels of my house destroying walls, ceilings, etc. What a nightmare!)

It was on SB Sunday. Rained steady for most of the day and was supposed to change to snow. Eventually it did switch over but that wasn't until late at night and then the precip shutoff leaving only a dusting to an inch tops. Not sure what the  initial call was for in terms of amounts after the changeover but I do remember the NWS forecast on the radio saying it would be significant.

[jacindc]

OMG, no one's mentioned the best part of the '87 storm? The city's response was so atrocious, but Mayor Barry was out at the Super Bowl, and mostly out of touch. The rumor/story later surfaced that he had ODed on cocaine that night and was in the hospital.

[kurtstack]

Just curious if anybody knows how the qpf verified sunday and today relative to the general model consensus?  Would be helpful for future reference this season.

[MN Transplant]

Just curious if anybody knows how the qpf verified sunday and today relative to the general model consensus? Would be helpful for future reference this season.

0.35" at DCA

0.30" at IAD

0.31" at BWI

Basically, the American models were a good bit too high, while the Euro had the general idea (other than temps).

[Bob Chill]

Just for giggles, there's another overrunning signal centered near xmas. Slow moving arctic boundary that clears the area and a se ridge. Having a hard time translating to sensible wx....any ideas?

[mdsnowlover]

Just for giggles, there's another overrunning signal centered near xmas. Slow moving arctic boundary that clears the area and a se ridge. Having a hard time translating to sensible wx....any ideas?

EC has a low off delmarva coast xmas eve and day

[Bob Chill]

FWIW- gfs op connects the ridge off the wc to the -epo ridge and a nasty cross polar flow after xmas. Lakes will be freezing in LA. Canal ice skating will be open.....and the ss is not dead...

[HM]

A lot of people are still trying to bring warmth into the game late month. Any warm-ups between now and 1/10 are brief and the cold wins with a solid NE PAC high in-place. Yes the stratospheric vortex will continue to tighten-up, but this is hardly going to matter when the Pacific is ruling the show here. The other argument for warmth was the "MJO" but I don't understand the logic. We haven't had a real MJO signal for a month now and it really hasn't correlated well with CONUS temps anyway (if you use the octant graphs. If you use the waves correctly, it is helpful). So, at this stage, you need a real good reason why things will suddenly change. If anything, they could get colder if wavelengths continue to elongate, allowing the NE PAC ridge to expand into the PNA domain.

 

All available guidance, NWP and not NWP, suggests another ridiculous EPO unloading by Christmas for most of the USA. I'm sure we will have another frontal wave winter potential too with it.

[mitchnick]

A lot of people are still trying to bring warmth into the game late month. Any warm-ups between now and 1/10 are brief and the cold wins with a solid NE PAC high in-place. Yes the stratospheric vortex will continue to tighten-up, but this is hardly going to matter when the Pacific is ruling the show here. The other argument for warmth was the "MJO" but I don't understand the logic. We haven't had a real MJO signal for a month now and it really hasn't correlated well with CONUS temps anyway (if you use the octant graphs. If you use the waves correctly, it is helpful). So, at this stage, you need a real good reason why things will suddenly change. If anything, they could get colder if wavelengths continue to elongate, allowing the NE PAC ridge to expand into the PNA domain.

 

All available guidance, NWP and not NWP, suggests another ridiculous EPO unloading by Christmas for most of the USA. I'm sure we will have another frontal wave winter potential too with it.

great news HM and thanks for your thoughts

with all the cold air on our side of the Pole I think we eventually get a moderate all snow event around here this winter, but no monster

[HM]

great news HM and thanks for your thoughts

with all the cold air on our side of the Pole I think we eventually get a moderate all snow event around here this winter, but no monster

 

Smaller-scale events are a lot harder to predict in the LR. But, I do agree that there is potential for a moderate event during this time. The original idea for the pre-xmas event was that retrograding would stop and then begin to progress again. Also, we would see the tropical forcing come back into the W PAC, enhancing the STJ. Unfortunately, we can't get the NAO/AO to help, so we obviously can't predict anything major.

 

So, the warm-up coming 12/20 or so isn't going to last long. That boundary and cold air source could produce a similar outcome to the last shot for much of the lower 48. Should we repeat the same scenario, it will only be colder this go-around.

[Bob Chill]

Thanks HM. I made a mistake in my post and said -wpo when I meant -epo. I changed it. 

 

Fascinating year for sure. Last year's nasty dec -AO was completely useless and we had an inverse relationship. Now we have the opposite inverse relationship. I know the pac is only part of the puzzle but 2 years in a row it's dominating Dec. 

 

Any thoughts on whether we actually get some blocking? Jan? Feb? Never? 

[usedtobe]

The 1986 storm was suppose to be on SB Sunday into the evening.. I remeber because we had just moved into our house two days earlier on the Friday.

 

Were the two 1987 storms imperfectly forcasted?  For some reason, I thought the first storm on Thursday was suppose to change to rain and it never did and there were lots of storires about people stuck in DC and on the roads. And for the second storm. I remember Bill Kamal on some private weatherline (Not the C&P telephone number) as being the first  to forcast the Sunday storm and wondering why the NWS had not posted Watches (or the equivalent back then). The second storm was a cold storm.  (The real reason I remember all this is I got to learn all about ice damming and by Tuesday morning I had water running thru three levels of my house destroying walls, ceilings, etc. What a nightmare!)

Actually, you're right about the 1st 1987 storm though at HPC I put out and 8 inch or greater contour that included DC and tried to get the forecaster from the local  forecast office to go with snow as the NGM never warmed at 850 while the old LFM did.   I had real good forecasts for both of those storms and because of that was asked to give a talk on snow forecasting at the local AMS chapter.

[usedtobe]

Both the euro ens and gefs seem to agree about a warm spell before christmas. Basically the 20-24th range in general. GEFS is quite warm. +10 kinda warm. Euro ens not as much but the se ridge gets an opportunity to flex. 

 

Leading into and after Christmas looks like another invasion of really cold air. Kinda similar to the pattern we just had with a deep arctic airmass into TX and a gradient right over us. 

 

It's a long ways out but there is general agreement with a noticeable relaxation for a short period of time. 

 

One feature that seems to have a pretty strong signal is anomalous + heights in the GOA. This will keep the country from getting flooded with pac air so that is very good even if we get a se ridge invasion for a period. 

 

Southern stream does not appear to die down anytime soon. If anything it looks to continue through the entire month overall. For not having any good blocking in the atlantic, the pattern we are in and where it goes is about as good as you can get. 

 

Tune in tomorrow for a completely different look in the lr. 

Bob, good post.  I agree with it.  The operable word is transient.  

[HM]

Thanks HM. I made a mistake in my post and said -wpo when I meant -epo. I changed it. 

 

Fascinating year for sure. Last year's nasty dec -AO was completely useless and we had an inverse relationship. Now we have the opposite inverse relationship. I know the pac is only part of the puzzle but 2 years in a row it's dominating Dec. 

 

Any thoughts on whether we actually get some blocking? Jan? Feb? Never? 

 

Bob, in the winter outlook thread, I posted a few AO graphics a while back for years like 1961-62 and 1990-91. The overall northern annular modes state, or NAM, seemed to favor +AO overall first half and -AO second half. This is typical of a +QBO winter. The westerlies are firmly entrenched below 30km with easterlies 30-40km. These have been correlated to delay any disturbance.

 

The PV will continue to intensify into early-mid Jan before possibly weakening thereafter. That's when I think the NAM state will start to get perturbed. The question is: will perturbing anything about the pattern mean we mess up the current pattern that delivers the cold? So, even though we get a -AO, would that force changes that make the Pacific more hostile? All of the magical late Jan-Feb periods had a nice overlap between favorable MJO and stratosphere. Having 1 occur without the other has usually led to more disappointment.