[donsutherland1]

A great Mid-Atlantic snowstorm is now imminent. Such a storm is consistent with the long-advertised idea of strong blocking (the latest AO reading was -3.378) and an active subtropical jet for February. More importantly, the Washington, D.C. to Baltimore area has been consistently modeled as having the highest amounts of snow. A 30” snowfall could occur in that vicinity. At the height of the storm, some thunder is possible in that region.

By the time the last snowflakes stop falling late Saturday or possibly early Sunday, Winter 2009-10 should be among the 5 snowiest winters on record in both Baltimore and Washington, D.C. Moreover, monthly snowfall in Washington, D.C. should be among the 5 highest figures for February. In Baltimore, monthly snowfall could be near or among the 5 highest figures for February.

Baltimore:
February snowfall through 2/4: 4.9”
Seasonal snowfall through 2/4: 35.6”

http://img.photobucket.com/albums/v327/donsutherland1/BWITable.jpg

Washington, D.C. (DCA):
February snowfall through 2/4: 3.3”
Seasonal snowfall through 2/4: 27.3”

http://img.photobucket.com/albums/v327/donsutherland1/DCTable.jpg

It should be noted that even as the 2/5 0z NAM came in notably drier from Philadelphia north and eastward, I have only trimmed amounts in those areas. SREF guidance and the GFS's continuity suggest that the NAM might be overdoing the magnitude of the gradient.

At this point in time, my estimates for the February 5-6, 2010 Snowstorm:

Allentown: 4”-8”
Baltimore: 16”-24”
Hagerstown: 12”-24”
Harrisburg: 6”-12”
New York City: 3”-6”
Newark: 4”-8”
Philadelphia: 10”-15”
Richmond: 4”-8”
Washington, D.C.:
…DCA: 16”-24”
…IAD: 16”-24”

http://img.photobucket.com/albums/v327/donsutherland1/KnickerbockerSnowstorm.jpg
Knickerbocker Snowstorm (NOAA Photo Library)

From the news caption on the January 29, 1922 edition of The Washington Post:

Washington center of driving blizzard that sweeps Virginia, Maryland, and Delaware—Snowfall exceeds all records…Capital paralyzed under deep blanket of white.

Streetcars and automobiles jammed in snowbound streets—population tied up in homes—Armament conference meetings halted—Congress activities practically suspended…

[winterymix]

Don:

Nice analysis, the 0Z GFS is supportive. As noted, the NAM came in a tad drier but Wes has
noted repeatedly that the GFS has been stable over a number of runs and thus can be
emphasized if doing a weighted average of models.

I thought that you might be intrigued by a 300mb feature from the 0Z GFS, a closed low at
300 mb. Am wondering if this will slow the progression of the system until it finishes the process
of becoming stacked vertically.

I'm thinking that in my region. we may receive a widespread foot of snow between midnight
local time on Saturday and sunrise Saturday.

 300mb.jpg (107.99K)
Number of downloads: 9

[SYRMAX]

Generally agree Don...I think our forecasts at ne.wx are going to be similar. Hard to pick out a specific station that'll under/overachieve.

SBY and RIC are interesting calls...I have SBY getting into some PL issues that'll hold down accums, the warm nose is very near them...RIC is another one...the timeing/placement of the H7 low will be critical for these two...the NAM gives them some decent wraparound (even ORF), which if true would give them upside potential. I had SBY at 9.5" and RIC at about 5"...I threw ORF an inch because I used to live there. Hopefully they get more than what I signed on for.

NYC also another tough one. I do think we get advisory level snow into the EWR/JFK/ISP corridor but not any further North.

Stunning to see the MA getting 2 of these in one season. Good for them.

[donsutherland1]

Thanks Winterymix.

I suspect that the idea of a foot of snow between midnight and sunrise Saturday is fairly likely where the most intense snows develop. It will be fun to see how things evolve.

[MidlothianWX]

Don, I really like your posts, thanks for the great information! I will be sure to send you pictures from the 1/30 storm as soon as I can.

Just one question from me: do you leave open the possibility of more snow for RIC, considering the fact that the 00Z models seem to pummel us with snow via the comma head on Saturday? My location has historically done better than RIC due to the fact that I am 25-30 miles west of the airport. Hopefully that helps me in this case!

[WEATHER53]

Great stuff Don. Your season long discussion and prediction of the AO I think has been the most illustrative, and apparently correct, such line of thinking that I have ever encountered on these weather boards.

[donsutherland1]

Thanks SYRMAX.

First, good luck in the NE.Wx contest.

Second, I share your concerns about the mixing at SBY. Given how large the differences are between the NAM and GFS, I erred on the colder side to give a little weight to any emergent trend the NAM might have picked up on. The storm's dynamics may also allow for a tad colder solution than what the earlier runs of the GFS were showing, though I have not yet seen the 0z GFS's soundings.

Finally, I agree with you concerning the Mid-Atlantic's receiving another mega snowstorm. It's good to see them receiving so much snow after the last three years in which below to much below normal snow fell during the winters.

[donsutherland1]

Thanks Jake.

I tried to PM you after the last event, but your inbox was full. I will look forward to any pictures.

As for Richmond, I believe the potential for more snow is definitely on the table. Just small differences in the storm's track or where the comma-head forms could allow for greater accumulations.

Enjoy the storm. Also, I am sure it won't be the last one for your area.

[donsutherland1]

Thank you for your very generous compliment, Weather53.

Enjoy the coming storm. It should be a memorable one.

[SabreAce33]

Thanks guys for taking the time to think about and comment on SBY. It gets a little lonely out here in the weeds, especially when everyone else in my region thread is jumping for joy.

[WEATHER53]

donsutherland1, on 04 February 2010 - 11:37 PM, said:

Thank you for your very generous compliment, Weather53.

Enjoy the coming storm. It should be a memorable one.

It's a statement of fact as much as a compliment. I am happy that Eastern has provided sane and stable commentary this winter without all the histrionics. Much better and more enjoyable I believe.

[MidlothianWX]

donsutherland1, on 04 February 2010 - 11:31 PM, said:

Thanks Jake.

I tried to PM you after the last event, but your inbox was full. I will look forward to any pictures.

As for Richmond, I believe the potential for more snow is definitely on the table. Just small differences in the storm's track or where the comma-head forms could allow for greater accumulations.

Enjoy the storm. Also, I am sure it won't be the last one for your area.

Thanks Don! I cleaned out my inbox!

[mikerc971]

Greetings from Michigan!

My wife and I have had planned for several months a trip to visit relatives in Glen Burnie. We were originally planning on embarking on Saturday, but due to this monster storm our plans have changed. Two days ago when I first caught wind of this potential storm, we decided to take off on Friday to try and get ahead of it. Over the past two days, however, the forecast models I've been watching have the storm coming in earlier on Friday than originally thought. So I guess we're going to wait it out and try our trip on Sunday.

For those of you who live near the I-70 area between the MD/PA border and Baltimore, how do you think I-70 is going to be come Sunday? If you guys really do see 16+ inches of snow by nightfall Saturday, do you think I-70 is going to be passable come Sunday afternoon?

Thanks alot!

[Ji]

I never bought that DC was not a snow town...I have seen many snow events. I think the drought we had was more of a cycle. There were very few Miller A's...not much blocking and really fast pac jet streams and lots of La Ninas. We are not Raleigh or Richmond. I have seen a ton of snow events in my life and i dont think its a fluke that we keep seeing HECS

[jak488]

Ji, on 05 February 2010 - 12:12 AM, said:

I never bought that DC was not a snow town...I have seen many snow events. I think the drought we had was more of a cycle. There were very few Miller A's...not much blocking and really fast pac jet streams and lots of La Ninas. We are not Raleigh or Richmond. I have seen a ton of snow events in my life and i dont think its a fluke that we keep seeing HECS

:lol: Yeah two HECS in one season is not out of the ordinary at all.

[scope1]

The dec storm i recieved 35" up here.....This storm could bring another 35".......I have seen crazy wild stuff up here buy i have never seen 2 storms in the same yr bring 70"???.....amazing......We have had 57" so far this yr and 2 bad zr storms....


nice write up don....



scope

[Huffwx]

scope1, on 05 February 2010 - 12:20 AM, said:

The dec storm i recieved 35" up here.....This storm could bring another 35".......I have seen crazy wild stuff up here buy i have never seen 2 storms in the same yr bring 70"???.....amazing......We have had 57" so far this yr and 2 bad zr storms....


nice write up don....



scope

You're going to get smoked up there. Have fun...

Final tally Danville 2 inches, Wintergreen 40...

[Schinz]

mikerc971, on 05 February 2010 - 12:03 AM, said:

Greetings from Michigan!

My wife and I have had planned for several months a trip to visit relatives in Glen Burnie. We were originally planning on embarking on Saturday, but due to this monster storm our plans have changed. Two days ago when I first caught wind of this potential storm, we decided to take off on Friday to try and get ahead of it. Over the past two days, however, the forecast models I've been watching have the storm coming in earlier on Friday than originally thought. So I guess we're going to wait it out and try our trip on Sunday.

For those of you who live near the I-70 area between the MD/PA border and Baltimore, how do you think I-70 is going to be come Sunday? If you guys really do see 16+ inches of snow by nightfall Saturday, do you think I-70 is going to be passable come Sunday afternoon?

Thanks alot!

I believe they will have I-70 open and passable by Sunday afternoon. They do a good job with 95, 70, 695 and 795...especially 18 hours or so after the snow ends. Even with blowing and drifting I think it will be passable, but I wouldn't try any earlier than sunday afternoon.

[SYRMAX]

SabreAce33, on 04 February 2010 - 11:47 PM, said:

Thanks guys for taking the time to think about and comment on SBY. It gets a little lonely out here in the weeds, especially when everyone else in my region thread is jumping for joy.

FWIW, in looking at the 00Z GFS and NAM Soundings for SBY...they both appear to stay <0C throughout the column (though close), which appears to be a bit of a trend in the colder (more snow) direction for SBY...if you can stay that way through the 1st half of the storm and then have the comma head / wraparound materialize, my 9.5" call is possibly underdone by a factor of 2. If the big qpf materializes and if you can stay snow, I'd bet you'll probably have 8:1 ratios when precip rate is highest, which would keep accums from getting out of hand (which I'm sure we actually want ;)). Something to watch.

[JamesNY]

Don,

Nice writeup. I sure hope you bust on the low side for NYC though. :snowman: