The Psuhoffman Storm

[WxUSAF]

mos is quite a bit warmer than that

What are the numbers? Just looking at the maps, the -10C 2m temp contour stays on or south of the Mason-Dixon line all day.

MOS usually runs warm, particularly with arctic airmasses if memory serves.

[Ian]

What are the numbers? Just looking at the maps, the -10C 2m temp contour stays on or south of the Mason-Dixon line all day.

MOS usually runs warm, particularly with arctic airmasses if memory serves.

12z was 28 at DCA and 24 at BWI with 27 IAD/JYO... 18z looks like it might be a smidge colder but you cant get mex on it i don't believe. I used to look at MOS every day but have not as much recently so I'm not sure what it's current bias is. I do think in general it tends to underplay severe cold or severe heat. Maybe somewhere in the middle of MOS and 2m temps? Honestly it wasnt even really on my radar.

[mitchnick]

Huh? So you think we should forecast based on the past events alone? Even using that interpretation, this pattern is completely different than the past forecasts "busts" for the DC/BA area and it features no anomalous blocking and a very amplified PNA ridge. Persistence alone only gets you so far--and if persistence worked so darn well--we would never need numerical models because nothing would ever change! If this is exactly how we forecasted today--there would be some seriously high impact to society forecast busts with severe implications.

I am saying that the chances of significant snow at BWI/DCA is next to nothing. I am 52. I have observed winter wx and patterns in Baltimore intensely since 1972. Maybe not where you come from, but there have been many winters around here where it just won't snow. Sure, synoptic circumstances are different with each storm in the season, but that did not change the result....no snow. In light of what has happened so far this year, I doubt it changes. Can it? Sure, but I think one must forecast with the season's pattern in mind. We do not do well in NINA's here and this year, a mod NINA, has been very unkind with respect to snow. That is my point in a nutshell. Climo is a biatch around here when it comes to NINA's and snow. This year has "skunk" written all over it. Equally important is the fact that the computers have been running the same show all winter and I'm seeing it again: 5 days out mega snow with each event, only to slowly fizzle with this morning being a perfect example of 1-3" forecasted by the NWS 12 hours in advance only to have <1/2" fall. Now, if it snows this winter, I expect you to step forward and say " I told you so" to which I will say, "bfd." To be clear, my position is that until we get a snow of significance, I assume it will not snow significantly no matter what the God-awful computers show. You may not agree with that position, so be it,but we will have to agree to disagree. In the end however, and contrary to what you may think, I hope I am wrong and you are right as the snow weenie in my heart will always prevail over competitive wx forecasting.

[baroclinic_instability]

I am saying that the chances of significant snow at BWI/DCA is next to nothing. I am 52. I have observed winter wx and patterns in Baltimore intensely since 1972. Maybe not where you come from, but there have been many winters around here where it just won't snow. Sure, synoptic circumstances are different with each storm in the season, but that did not change the result....no snow. In light of what has happened so far this year, I doubt it changes. Can it? Sure, but I think one must forecast with the season's pattern in mind. We do not do well in NINA's here and this year, a mod NINA, has been very unkind with respect to snow. That is my point in a nutshell. Climo is a biatch around here when it comes to NINA's and snow. This year has "skunk" written all over it. Equally important is the fact that the computers have been running the same show all winter and I'm seeing it again: 5 days out mega snow with each event, only to slowly fizzle with this morning being a perfect example of 1-3" forecasted by the NWS 12 hours in advance only to have <1/2" fall. Now, if it snows this winter, I expect you to step forward and say " I told you so" to which I will say, "bfd." To be clear, my position is that until we get a snow of significance, I assume it will not snow significantly no matter what the God-awful computers show. You may not agree with that position, so be it,but we will have to agree to disagree. In the end however, and contrary to what you may think, I hope I am wrong and you are right as the snow weenie in my heart will always prevail over competitive wx forecasting.

I am a winter pessimist too--but with a tinge of realism. I think you are too overly pessimistic of this threat--even if it involves periods of rain as a possible solution. In previous threats--they truly were low probability threats. There is no wackie double or triple phases needed with this threat--and even a faster, weaker, and dryer GFS solution with no GOM influence can still deliver the goods. Feb 2010 goods? No--but better than nothing. I wouldn't discount the threat based off seasonal trends alone here. That said--I understand where you are coming from--but past seasonal trends and analogs can only go so far.

[WxUSAF]

12z was 28 at DCA and 24 at BWI with 27 IAD/JYO... 18z looks like it might be a smidge colder but you cant get mex on it i don't believe. I used to look at MOS every day but have not as much recently so I'm not sure what it's current bias is. I do think in general it tends to underplay severe cold or severe heat. Maybe somewhere in the middle of MOS and 2m temps? Honestly it wasnt even really on my radar.

The 18z GFS shows the -10C line maybe a little south of of where it was on the 12z for Monday at 18z. Not much difference.

It's been a long time since I've had to use MOS for a forecast, but it usually went way too warm with arctic air. MOS always "runs to climo" was kind of the rule-of-thumb we used and you had to tweak it for factors like snowcover, arctic air, cloud cover, etc...

LWX has highs of 28 in DC and 26 in Baltimore for Monday. I'd probably drop those each by 5F.

[real]

I am saying that the chances of significant snow at BWI/DCA is next to nothing. I am 52. I have observed winter wx and patterns in Baltimore intensely since 1972. Maybe not where you come from, but there have been many winters around here where it just won't snow. Sure, synoptic circumstances are different with each storm in the season, but that did not change the result....no snow. In light of what has happened so far this year, I doubt it changes. Can it? Sure, but I think one must forecast with the season's pattern in mind. We do not do well in NINA's here and this year, a mod NINA, has been very unkind with respect to snow. That is my point in a nutshell. Climo is a biatch around here when it comes to NINA's and snow. This year has "skunk" written all over it. Equally important is the fact that the computers have been running the same show all winter and I'm seeing it again: 5 days out mega snow with each event, only to slowly fizzle with this morning being a perfect example of 1-3" forecasted by the NWS 12 hours in advance only to have <1/2" fall. Now, if it snows this winter, I expect you to step forward and say " I told you so" to which I will say, "bfd." To be clear, my position is that until we get a snow of significance, I assume it will not snow significantly no matter what the God-awful computers show. You may not agree with that position, so be it,but we will have to agree to disagree. In the end however, and contrary to what you may think, I hope I am wrong and you are right as the snow weenie in my heart will always prevail over competitive wx forecasting.

Last year, I swore it was not possible for D.C. to get more than 15 inches of snow in December pre-Xmas. I was wrong. A few months later, I bet against the Feb. 10 storm being any of significance just because it seemed so impossible to get back to back blizzards here. I was wrong. Living in Pennsylvania in 1993 I swore it was not likely to get 2 feet of snow in mid March, I was wrong. Hell, a few days ago, I didn't think it as possible for my street in the city of DC to have thick accumulating ice on it when it didn't appear it was going to be that cold -- (you know how rare it is for ice to accumulate on streets in the city from freezing rain?) - I was wrong.

I could go on and on. Not dismissing that patterns matter, and you have every right to be skeptical, but don't turn a blind eye either if things start looking in a day or two like, yes, it will snow.

[Ian]

The 18z GFS shows the -10C line maybe a little south of of where it was on the 12z for Monday at 18z. Not much difference.

It's been a long time since I've had to use MOS for a forecast, but it usually went way too warm with arctic air. MOS always "runs to climo" was kind of the rule-of-thumb we used and you had to tweak it for factors like snowcover, arctic air, cloud cover, etc...

LWX has highs of 28 in DC and 26 in Baltimore for Monday. I'd probably drop those each by 5F.

no, it definitely has its biases and climo is part of it. sometimes they arent that pronounced though. for instance it misses downsloping by several degrees almost every time there is downsloping.

[baroclinic_instability]

I am saying that the chances of significant snow at BWI/DCA is next to nothing. I am 52. I have observed winter wx and patterns in Baltimore intensely since 1972. Maybe not where you come from, but there have been many winters around here where it just won't snow. Sure, synoptic circumstances are different with each storm in the season, but that did not change the result....no snow. In light of what has happened so far this year, I doubt it changes. Can it? Sure, but I think one must forecast with the season's pattern in mind. We do not do well in NINA's here and this year, a mod NINA, has been very unkind with respect to snow. That is my point in a nutshell. Climo is a biatch around here when it comes to NINA's and snow. This year has "skunk" written all over it. Equally important is the fact that the computers have been running the same show all winter and I'm seeing it again: 5 days out mega snow with each event, only to slowly fizzle with this morning being a perfect example of 1-3" forecasted by the NWS 12 hours in advance only to have <1/2" fall. Now, if it snows this winter, I expect you to step forward and say " I told you so" to which I will say, "bfd." To be clear, my position is that until we get a snow of significance, I assume it will not snow significantly no matter what the God-awful computers show. You may not agree with that position, so be it,but we will have to agree to disagree. In the end however, and contrary to what you may think, I hope I am wrong and you are right as the snow weenie in my heart will always prevail over competitive wx forecasting.

And no, I don't bother with such silliness. Nobody is ever right or wrong all the time--nor am I claiming to be right here. In fact, all I am really getting at is every setup is unique, and no amount of previous "busts" by the models, seasonal weather trends, or La Nina changes a particular short-term dynamic scenario. I am not claiming a big bombastic snowbomb for the MA--just that one should be careful with seasonal trends alone--and such use will sooner or later possibly bust in a big way. There is no such thing as being "right or wrong" in meteorology. Only the atmosphere is right--humans always lose.

[NinjaWarrior2]

18z DGEX gives DC/BALT flash floods lol, 2+ inches of rain in 12 hours, imagine if this was snow

[samdman95]

18z DGEX gives DC/BALT flash floods lol, 2+ inches of rain in 12 hours, imagine if this was snow

Dude. It's the freakin' DGEX from 5 days out.

[eurojosh]

Last year, I swore it was not possible for D.C. to get more than 15 inches of snow in December pre-Xmas. I was wrong. A few months later, I bet against the Feb. 10 storm being any of significance just because it seemed so impossible to get back to back blizzards here. I was wrong. Living in Pennsylvania in 1993 I swore it was not likely to get 2 feet of snow in mid March, I was wrong. Hell, a few days ago, I didn't think it as possible for my street in the city of DC to have thick accumulating ice on it when it didn't appear it was going to be that cold -- (you know how rare it is for ice to accumulate on streets in the city from freezing rain?) - I was wrong.

I could go on and on. Not dismissing that patterns matter, and you have every right to be skeptical, but don't turn a blind eye either if things start looking in a day or two like, yes, it will snow.

Agree.

I'd also point out that our sample set for weather experience is tiny - 150 years in the best case for a solid temps record, 240 years for snowfall... All our thinking and models are predicated on a dataset that represents a miniscule fraction of climatological experience.

[birdsofprey02]

18z DGEX gives DC/BALT flash floods lol, 2+ inches of rain in 12 hours, imagine if this was snow

Dude. It's the freakin' DGEX from 5 days out.

[PhineasC]

18z DGEX gives DC/BALT flash floods lol, 2+ inches of rain in 12 hours, imagine if this was snow

STOP POSTING THE DGEX

[Kmlwx]

STOP POSTING THE DGEX

Also stop analyzing the DGEX. Or even looking at it for that matter.

[mitchnick]

18z DGEX gives DC/BALT flash floods lol, 2+ inches of rain in 12 hours, imagine if this was snow

if anything, and I am actually serious here, that is a good sign because the DGEX has never shown a heavy rain event for any snow threat this season at DCA/BWI

again, I'm looking for something (OK then, anything) that will show a break in this snow-less pattern for us e.g. JI, JB and DT sharing a ride to the NE snow conference in March

[Ian]

Agree.

I'd also point out that our sample set for weather experience is tiny - 150 years in the best case for a solid temps record, 240 years for snowfall... All our thinking and models are predicated on a dataset that represents a miniscule fraction of climatological experience.

again a small sample, but it's a heck of a lot easier to get big snow in a nino than a nina here .. 12/26 hitting east of here aside etc. march is a good time to get surprises as spring starts to rear its head with more moisture and more temperature variability for a biggy storm. even if all the models were locking in on 6-12 or 12-18 in this range i'd have a pretty hard time believing them verbatim. it also helps frame the idea that, especially if you're in the cities, your chances for a slop storm or a graze or a miller b screwjob are still relatively high compared to the best solutions. i guess if you're happy with a few inches and then either rain or done etc you have some things to be hopeful for given current guidance. there are some things (or maybe general ideas) which have remained constant but there is still plenty of variability of recent and more should be expected since we're still a few days out.

[Ian]

if anything, and I am actually serious here, that is a good sign because the DGEX has never shown a heavy rain event for any snow threat this season at DCA/BWI

again, I'm looking for something (OK then, anything) that will show a break in this snow-less pattern for us e.g. JI, JB and DT sharing a ride to the NE snow conference in March

it might be a good sign for leesburg and his drought monitoring

[yoda]

Let the 00z model chaos begin! SREFs will be finished in a few

[SomeguyfromTakomaPark]

again a small sample, but it's a heck of a lot easier to get big snow in a nino than a nina here .. 12/26 hitting east of here aside etc. march is a good time to get surprises as spring starts to rear its head with more moisture and more temperature variability for a biggy storm. even if all the models were locking in on 6-12 or 12-18 in this range i'd have a pretty hard time believing them verbatim. it also helps frame the idea that, especially if you're in the cities, your chances for a slop storm or a graze or a miller b screwjob are still relatively high compared to the best solutions. i guess if you're happy with a few inches and then either rain or done etc you have some things to be hopeful for given current guidance. there are some things (or maybe general ideas) which have remained constant but there is still plenty of variability of recent and more should be expected since we're still a few days out.

I agree with this. I just like how if you kind of take an average of all the guidance the track is 'in our wheelhouse' for success. So far this winter we haven't had a look yet where all the models were close to something for us.

[Bob Chill]

it might be a good sign for leesburg and his drought monitoring

Ian, do you at least agree that it is likely that we see .50+ of precip out of this event? Temp details can be worked out inside of 48 but from everything I looked at today, the odds of seeing at least a half inch of precip look to be 75% or better.

[yoda]

Some food for thought before the 0z GFS initializes:

La Niña KU Snowstorm Statistics for Cases when the Region 3.4 Anomaly was -0.50 or lower and the Region 1+2 Anomaly was < 0:

- 4/5 (80%) occurred when the AO was < 0; 3/5 (March 1956, January 1996, December 2000, and December 2010); the exception was the January 2000 snowstorm

- (60%) occurred when the AO was < -2

- 3/4 (75%)--No GWO stats were kept prior to 1958--occurred when the GWO was in Phase 4 (January 1996, January 2000, and December 2010)

The AO is forecast to be rising quickly but could still be somewhat negative around the January 25-26 timeframe. The GWO is currently in Phase 4.

[yoda]

First up, way out there of course... but FWIW... the 21z SREFs at 87 h5

[Ian]

Ian, do you at least agree that it is likely that we see .50+ of precip out of this event? Temp details can be worked out inside of 48 but from everything I looked at today, the odds of seeing at least a half inch of precip look to be 75% or better.

if not for the gfs i think i could agree though 75% odds at d4+ are pretty high. 18z gfs doesnt have much support tho so maybe it should be discarded entirely. but after hugging the gfs for weeks i dont know if i can do that.

[Bob Chill]

if not for the gfs i think i could agree though 75% odds at d4+ are pretty high. 18z gfs doesnt have much support tho so maybe it should be discarded entirely. but after hugging the gfs for weeks i dont know if i can do that.

Fair enough. Maybe the 0Z GFS turns up the juice and pushes the dreaded H5 vort down around the VA/NC border....

[PhineasC]

Fair enough. Maybe the 0Z GFS turns up the juice and pushes the dreaded H5 vort down around the VA/NC border....

We pretty much just need it to not move at all. A tall order, and why folks are rightfully cautious.

[Bob Chill]

Part of me wants to believe that temps will be in our favor because it has just plain wanted to be below normal this winter. Marginal temps on the models will probably verify colder. The last ice storm is a pretty good example of this recently.

[Bob Chill]

We pretty much just need it to not move at all. A tall order, and why folks are rightfully cautious.

Well, when you put is that way.....

[PhineasC]

Part of me wants to believe that temps will be in our favor because it has just plain wanted to be below normal this winter. Marginal temps on the models will probably verify colder. The last ice storm is a pretty good example of this recently.

The GFS and Euro have pretty different evolutions at this point. If the GFS solution verifies, temps won't be an issue, but we could get screwed on precip. If the Euro solution verifies, we get plenty of precip but temps are iffy.

[Ian]

The GFS and Euro have pretty different evolutions at this point. If the GFS solution verifies, temps won't be an issue, but we could get screwed on precip. If the Euro solution verifies, we get plenty of precip but temps are iffy.

those are the two most logical camps unfortunately. i think it will be hard to get a bomb up the coast without worrying about temps at all. obviously we can say that about a lot of big storms.

[Wonderdog]

The GFS and Euro have pretty different evolutions at this point. If the GFS solution verifies, temps won't be an issue, but we could get screwed on precip. If the Euro solution verifies, we get plenty of precip but temps are iffy.

Yeah, I tend to think the "warmer" the temps turn out to be with this storm, the more precip we will see

.