February 6-8: Likely Miss for East Coast's Big Cities

[donsutherland1]

With the end of the week and at least the first part of the weekend looking to be stormy, the proverbial winter question as to whom will receive big snowfalls again takes center stage.

Unfortunately, for those living in the Washington, DC to New York City megalopolis, a big snowfall does not appear to be likely. For Boston to Portland, a moderate and perhaps significant snowfall appears more likely.

Based on the latest model guidance, including the 2/4 12Z GFS, it appears that the stormy period will likely be a tale of three systems:

1) A primary system that will bring warm air advection/overrunning snows to the northern Mid-Atlantic and Northeast.
2) A secondary storm that will develop along the Mid-Atlantic Coast
3) A second coastal storm that will try to develop along the Carolinas on the heels of the aforementioned secondary storm.

Currently, there is much uncertainty. A look back at past patterns with similarities to the current one reveals at least 6 such instances.

With respect to snowfall, the following held true:

- 50% (3) had at least some snowfall
- 17% (1) had a big snowfall from the northern Mid-Atlantic to New England

If one examines forecast soundings, there is little question that the precipitation will begin either later Thursday night or Friday morning as snow. Afterward, the warmer air will likely sweep northward and change the precipitation to sleet, freezing rain and then rain, particularly along the Coast.

If there is to be a big snowfall, everything would have to come together just right out of an already highly complex situation. If one examines the broader teleconnection indices, this looks like a losing struggle.

- The PNA should be rising but it will be a case of too little too late.
- The NAO is weakly negative to neutral and is likely to remain there. No Greenland block is present.
- A 50-50 Low could prove decisive but this probably won't be in place in time.
- The pattern remains progressive.

Given this situation, I believe the 12Z run of the GFS, though not perfect, is offering the outlines of a reasonable scenario. It develops a strong secondary system that tracks very close to the Coast. It then develops a second system on its heels but too far out to sea to be of much consequence. Thus, once sufficiently cold air is in place for the Coast to see accumulating snow, the moisture is not readily available.

Overall, my initial ideas as to total snowfall during the February 6-8 period follow:

Albany: 3"-6"
Boston: 4"-10"
Danbury: 2"-4"
Morristown: 2"-4"
New York City: 1"-3"
Philadelphia: 2" or less
Providence: 4"-8"
Washington, DC: 2" or less

All said, I expect total qpf in these cities to generally range from 1.25" to 2.50".

These are preliminary ideas and are subject to change. My confidence at this time remains low given the occurrence of a major snowfall in an analysis of past patterns, continuing model disagreements, and the complexity of the overall situation.

Finally, for those looking for a snowy February, it appears fairly likely that a major amplification could occur around or just after mid-month, and this could bring with it the potential of a large snowfall consistent with the <b>ideas</b> noted late last month.

[Lowpressure]

Sounds very good. Good objective analysis.

[blizzard20]

look at the ggem and boston discussion today.

[JCT777]

Thanks for the discussion, Don. I am hopeful that later in the month will be better for snow in my area. Rain in early February is depressing.

[WXBUFFJIM]

I wouldn't be at all surprised from Philly, DC, and Baltimore south and east just see all rain from this system. With a more southeasterly flow, that's bound to happen quick. So yea this is a somewhat similar storm as the last one. Only difference is the higher QPF potential.

Jim

[Anonymous]

Need I affirm that the ground is already quite saturated and frozen, and that 2.5 qpf means a ton of heavy rain for places already awash in ground moisture?

Boy I hope spring is drier; I hate floods. The way this wild STJ is already behaving, we could be facing catastrophe come spring with all its convective rains in the MA.



-Jeb

[Anonymous]

Hey Donald,

we better hope for a Big February. Boston needs alot of catching up to do to meet your forecast after a fast start--

I think a big storm between the 12th and 17th is possible with pna and the deep trough forecasted per ensembles.

[weatherfan]

If any one has notive the Sst chart in the Alantic has really change from what it was in the first part of the winter.Where it was warm so the NAO was only weakey to at times moderate negative.But now the Alantic waters have really cooled with warm waters near Green Land this is now a classest look of a Negative NAO and at time strong blocks.So imo dispite the NAO coming up weaky postive it would it surpise me if this is just sort lived and the NAO gos back to negative again.And as for a snowey febuarey yes I would tend to agree Don IF we can get timeing to set up right where we get the two streams to come togeather and get some phaseing going.The problem this winter is that the modles have a seriouey hard time handeling the different s/ws and tend to mess it up.So we get these forecasts every 7 to 10 days of possable good set ups for major winter storms only to lessen as we get closer.Because of the Darn PJ and s/w problems for eather phaseing to early or to late or none at all.And this next storm is no exceation to the rule for this winter this far unfornatey for those that wants a major snow storm. So until we accually see a clear cut sign of a real phaseing event and not these false alarms coming from the modles every 7 to 10 days.I exertsize exstream caution.But also staying opermistic that eventurey these things will at some point earther mid to late Month or early March comes to togeather.We will see.

[smiley]

If any one has notive the Sst chart in the Alantic has really change from what it was in the first part of the winter.Where it was warm so the NAO was only weakey to at times moderate negative.But now the Alantic waters have really cooled with warm waters near Green Land this is now a classest look of a Negative NAO and at time strong blocks.So imo dispite the NAO coming up weaky postive it would it surpise me if this is just sort lived and the NAO gos back to negative again.And as for a snowey febuarey yes I would tend to agree Don IF we can get timeing to set up right where we get the two streams to come togeather and get some phaseing going.The problem this winter is that the modles have a seriouey hard time handeling the different s/ws and tend to mess it up.So we get these forecasts every 7 to 10 days of possable good set ups for major winter storms only to lessen as we get closer.Because of the Darn PJ and s/w problems for eather phaseing to early or to late or none at all.And this next storm is no exceation to the rule for this winter this far unfornatey for those that wants a major snow storm. So until we accually see a clear cut sign of a real phaseing event and not these false alarms coming from the modles every 7 to 10 days.I exertsize exstream caution.But also staying opermistic that eventurey these things will at some point earther mid to late Month or early March comes to togeather.We will see.

How you can make a post like that on a board with a spell check option is beyond me.

[donsutherland1]

Ji and Weatherfan,

I do believe February will end up snowy. Although the coming late week-early weekend storm might bring a small amount of snow to parts of the MA and NE, one should not lose hope for the rest of the month.

As a more amplified pattern establishes itself around mid-month and colder air is nearby to be tapped, there could be a good opportunity for a significant and even major snowfall.

Historical analogs and also some of the ensemble guidance is backing such an idea.

[FLguy]

Ji and Weatherfan,

I do believe February will end up snowy. Although the coming late week-early weekend storm might bring a small amount of snow to parts of the MA and NE, one should not lose hope for the rest of the month.

As a more amplified pattern establishes itself around mid-month and colder air is nearby to be tapped, there could be a good opportunity for a significant and even major snowfall.

Historical analogs and also some of the ensemble guidance is backing such an idea.

Excellent discussion, Don.

the Atlantic tripole (SSTA set-up) would suggest a -NAO as much as 75% of the time. as far as the big event is concerned (bigger than DEC 03) --- IMO it waits for the first week of march. however there may be another MORE WIDESPREAD significant event before that; later this month.

[donsutherland1]

A quick update...

A look at the 12Z GFS soundings suggests that the snow-sleet-rain changeover for Philadelphia through Boston will occur as follows:

Boston: 2/6: 18Z-21Z
New York City: 2/6 9Z-12Z
Philadelphia: 2/6 6Z-9Z

The 18Z run of the ETA is in and it does not take away from the overall ideas sketched out at the beginning of this thread.

All said, looking back at some past patterns with similarities to the current one, I have to say that the computer guidance is actually handling a very complicated situation fairly well. In other words, it is not deviating greatly from how most past similar situations resolved themselves.

As one of the past years in question had a major snowfall for parts of the region, I remain somewhat wary of the situation. Needless to say, in my view, given that most of those past years did not have such a storm, along with the backing of a growing body of model guidance, the idea of a big snowstorm for the I-95 cities remains a low-risk proposition at this time.

This does not mean that some areas cannot nor will not receive a significant snowfall. Cities such as Allentown, Binghamton, Syracuse, Albany, could well receive 6" or more snowfall from this event. Moreover, Boston and Providence should do far better than Philadelphia or New York City with regard to total snowfall.

[Colin]

Don, I highly doubt Allentown has a chance at 1", much less 6"+...

[donsutherland1]

Thanks, FLguy. You may well be right about an event that would surpass the December 2003 blizzard and the timing of such an event. Overall, I'm not unhappy how things stand at this point in time with regard to snowfall and the prospect for snowfall for the month as a whole.

[Chris the Weather Man]

March= Miller A Time........ Don, I would love to see another Blizzard of 1983, this year....... And, Major snowstorm, for the MA/NE....... over 18+ inches.........

[FLguy]

March= Miller A Time........ Don, I would love to see another Blizzard of 1983, this year....... And, Major snowstorm, for the MA/NE....... over 18+ inches.........

probably, and an event such as FEB 83 isnt out of the question.

[donsutherland1]

Colin,

I should have been more clear. I didn't mean to suggest that 6" or more in Allentown is a certainty but rather a possibility, hence I used the word "could."

As for actual amounts, I'll have a better idea tomorrow, but it would not suprise me to see Allentown in the 2"-4" and maybe even 3"-6" range Friday morning at the time of the changeover to sleet, freezing rain, and then rain.

Perhaps I'm a little overoptimistic here.

We will see.

[FLguy]

Colin,

I should have been more clear. I didn't mean to suggest that 6" or more in Allentown is a certainty but rather a possibility, hence I used the word "could."

As for actual amounts, I'll have a better idea tomorrow, but it would not suprise me to see Allentown in the 2"-4" and maybe even 3"-6" range Friday morning at the time of the changeover to sleet, freezing rain, and then rain.

Perhaps I'm a little overoptimistic here.

We will see.

your probably pretty close, but i would go with a general 2-6" across the lehigh valley into the poconos and wilkes-barre scranton areas. ice is more the concern at least IMO given the still decent snow pack and near frz boundary layer temps in the deeper valleys

[donsutherland1]

FLguy,

I agree with you.

All the numbers are initial thoughts at this time. We'll see how things evolve.

[donsutherland1]

Chris,

You may well be right. I think there's a reasonable possibility of such a storm before the winter is finished.

Who wouldn't love to see an 18"+ snowstorm? On the other hand, I had better withdraw my question, as I know some who most definitely would not like to see such a storm.