washingtonpost.com
Blizzard warning for entire region

Steve Tracton
Meteorologist, Capital Weather Gang
Wednesday, February 10, 2010; 2:00 PM

"Extremely dangerous winter weather conditions were reported this morning for the Baltimore-Washington region and the eastern panhandle of West Virginia," according to the Capital Weather Gang on their blog.

"At 7:27 a.m. this morning a wind gust was recorded at 60 mph in Manassas, Va. Numerous wind gusts over 40 mph have been observed around the region along with white-out conditions."

Steve Traction, meteorologist with the Capital Weather Gang, was online Wednesday, Feb. 10, at 2 p.m. ET to discuss the latest on the explosive winter storm.

____________________

Steve Tracton: Thanks for joining this chat session.

For snow lovers (like me) it doesn't get much better than this. For those not so enamored, or just plain sick of snow, just remember the long string of years since it's been since you've had to deal with a Big One. Whatever your feelings, even if there is not a single flake after this storm, it's safe label this winter as The Snowmongous Winter of 2009-2010.

_______________________

SoMD: Just wanted to say thanks for all of the great coverage throughout these recent storms. The CWG has become my main on-line reference for weather-related issues. So, now that the snow appears to be leaving us, how long until temps get back to the normal range (mid-40's for this time of year, right?).

Steve Tracton: SoMd: Thanks for the thanks: It's not easy, but we're proud that CWG is increasingly becoming THE one-stop-shop for all things weather, especially for high impact events such as today's snowstorm.

_______________________

Glover Park, D.C.: I assume the fed gov't will be closed tomorrow; what do you think the odds are for opening by Friday?

Steve Tracton: If it were my call, which of course it is not, I'd keep the Government closed on Thursday. Travel conditions are likely to be rough and even dangerous for much of the day.

Stay tuned for OPM official announcement, which we'll report as soon as available.

_______________________

More snow on Monday?!: Really? Really? What are your thoughts/predictions about this Monday storm?

Thanks again for the CWG's great work -- I appreciate your work, and your site is the first site I turn to for weather! I'm quite the addict now.

Steve Tracton: It's much too early to call. We'll be sure to stay on top of developments, but there is no objective basis for calling the shots at this time

_______________________

Silver Spring, Md.:

Will weather conditions modify to allow the opening of Dulles Airport on Thursday?

Steve Tracton: The weather tomorrow will not interfere with flight operations at local airports. It's dealing with the consequences of today's weather that will be the deteriorating factor (snow removal, airline dependent directions).

I have a flight tomorrow PM, but the airline insists as of now it expects it will be a go. But, of course, this may change. Check with your own airline from time to time!

_______________________

Anonymous: Haven't seen any snowfall amounts -- how much in downtown DC

Steve Tracton: I'm not sure of the official measurement at DCA now. I'm directly across the river from DCA along the waterfront with exactly 10" of new snow.

_______________________

Annapolis, Md.: Yesterday the CWG indicated that we were not going to receive anymore snow for a while. Bob Ryan said we were clear for a while after this one. Now I hear we are going to have another big one on Monday?

Steve Tracton: Depends upon the definition of "for a while". I take this as meaning there is very little chance for measurable snow for at least the next several days.

_______________________

Alexandria, Va.: How do you get accurate (or even approximate) snow totals when the wind blows the snow so much? We knew we had 4 inches by around 10 last night, but have no idea how much additional we've gotten with this wind.

Steve Tracton: The best way would be to find an open spot protected from the wind. Otherwise, take measurements within an open area at several spots with the least and most snow and take the average.

_______________________

Rosslyn, Va.: I heard that DC might get a record amount of snow this year, based on records that go back to 1888. Since D.C. was founded in 1790, why weren't records kept in the first 100 years of the District's existence? Are there earlier records for nearby cities, such as Alexandria or Baltimore?

Steve Tracton: There are several sources of historical reports of snow storms. But before the late 1800's they were no sanctioned "official" measurements. Most of the historical accounts are in journals and diaries (e.g., Thomas Jefferson and Ben Franklin) at locations beyond DC.

FLASH: I just heard that DCA reports 8.7" as of 1PM.

_______________________

Snowed-in, Va.: Could you walk us through what the next few days will be like? Not in terms of forecast, but what conditions are likely to be in terms of melting snow, getting around easily, etc.?

Steve Tracton: Temperatures will have difficulty getting much above the mid 30's with re-freezing each night at least through the weekend. With strong sunshine and lengthening days, there will be melting with slush conditions on plowed pavements. Re-freezing will make it treacherous not too long after dark through early mornings. BE CAREFUL OUT THERE!!

_______________________

Silver Spring, Md.: Thanks for all the great coverage.

Can you give us a rough estimate on the timing of the snow tapering off? I know earlier, it was said maybe 2-4 p.m. But on radar, it looks like bands are coming in pretty strong from the North/Northwest. Will that extend the snow? And what about the wind?

Steve Tracton: Snow should be tapering off soon in the DC Metro region and probably no later than about 5-6 PM from Baltimore northeastwards. Extent of rap-around snow is moving steadily to the northeast. Winds should diminish rapidly after midnight.

_______________________

washingtonpost.com: The chat started prematurely, please excuse us. Meteorologist Steve Tracton will resume posting live answers to the chat at 2 p.m. ET. Thank you.

_______________________

Falls Church, Va.: Two items:

First, thanks so much for being informative. I like the details on underlying causes of weather patterns (being mildly educated in meteorology). The CWG is BY FAR THE BEST source of weather information in this area.

Second, what are the predictions about when the Arctic polar situation (the one that is shoving all the cold air southward) will weaken or otherwise return to what we think is a more normal pattern.

Thanks again, CWG rocks.

Steve Tracton: From what I can infer from the "tools" used at CPC, it appears that the current pattern over the arctic is not likely to break down for at least a week and perhaps not before the end of February.

_______________________

Snowthesda, Md.: If the temperatures were average every day after today's snowfall and with no new snowfall, how long would it take all of this snow to melt?

Steve Tracton: "All" the snow??? There are humongous piles of snow out there that might take weeks or longer to totally disappear.

_______________________

Arlington, Va.: Of these three storms (December, weekend and today), which do you think will spawn the most doctoral dissertations?

Keep up the good work! :-)

Steve Tracton: As a research meteorologist I'd view this SNOWMONGOUS winter as the subject of many theses, especially addressing the differing predictability of the individual storms in the background of El Nino conditions. I plan a post on some of the broader non geek aspects, for example, why the weekend storm was more predictable (high confidence) versus today's blizzard (lots of uncertainty right up to last moment).

_______________________

Alexandria, Va.: The sun is breaking through the clouds over Dogue Creek right now, snow is light. Does this mean the worst is over?

Steve Tracton: For you (Alexandria), YES

_______________________

NW D.C.: What is the meteorological term for an area being repeatedly hit with snow as is occurring here this year (and in Milwaukee and Madison a couple of years back)?

Steve Tracton: Dumped upon.
More seriously, the large scale atmospheric circulation has settled down with conditions favorable for recurrent storm activity affecting this region.

_______________________

Washington, D.C., SE: Hi CWG -- you guys are my new heroes these past weeks. I've just moved to D.C. and am glad to have found your blog.

I'm wondering what you have to say about climate change when people ask if this proves whether it is or is not happening. Clearly, one single weather event can't do either, but what's a good response?

Steve Tracton: You already have a good response and the one I use: One single event, or even series of events like the storms this year, are not evidence for or against the occurrence of global warming. I'd have more to say, but this is not the proper forum.

_______________________

Oakton, Va.: What near-term effect will this thick and lingering snowpack have on weather conditions and temperatures across the region?

Steve Tracton: The most obvious effect of the snow pack will be to reduce night time temperatures due to increased radiational cooling (when skies are clear)

_______________________

Washington, D.C.: Earlier today I heard an official from Washington DC say that the budget for snow removal and response is set for about 20 inches per year. Considering we are now over 70 inches for the season, I wonder if the Almanac predicted these storms?

(Seriously, I know major music festivals consult the almanac to find out what to expect weather wise)

Steve Tracton: I personally don't know (or care) what the Almanac said about this winter.

I'm waiting to hear what communities did with $$ budgeted for snow removal all those years when there was very little snow.

_______________________

Ellicott City, Md.: I grew up in Erie, PA. I never thought I would miss Erie in the winter!

We've got a wedding in Boston on Sunday. We were planning to drive on Friday, but now are considering either driving on Saturday or canceling. Any idea how traffic on 95 will be this weekend?

Thanks for the great blog.

Steve Tracton: I'd wait until at least Saturday. Main highways should be clear by then, but be careful of refreezing if driving at night.

_______________________

washingtonpost.com: The Federal Eye With Ed O'Keefe

_______________________

Washington, D.C.: Can you explain wrap around process that is taking place right now?...is it ever the case the wrap around in the low fills in and expands the storm, not just delay the end?

Steve Tracton: Yes, and that's what happened especially in Snowmageddon. Wrap around refers to precipitation developing on the backside (western quadrant) of a storm as the intensifying circulation forces moist air to rise over and around features of the upper level frontal structure.

_______________________

Maple Lawn, Md.: Is it purely a coincidence that we had two big storms back to back, or was the second storm in some way related to the first?

Steve Tracton: It's not a coincidence in that each storm was bred by successive disturbances originating over the Pacific "phasing" with disturbances coming down from the NW over western Canada. It is a coincidence that just the right combination of precursors led to the back to back storms.

_______________________

Washington, D.C.: Does this snowy winter provide any insight into the type of spring we will have this year?

Steve Tracton: NO, in my humble opinion.

_______________________

Anonymous: Some are saying the big storms prove "global warming" is just a myth and many scientists are wrong. Others, typically using the term "climate change," are saying the storms could in fact be proof of change, and note that scientists who believe in climate change don't say it will be uniformally warmer all the time everywhere. What do you think? Or is there a third option-- the current storms say nothing either way about the existence of climate change/global warming, and they are just a big pain, not a boon for anyone's political beliefs?

Steve Tracton: I provided an answer to this earlier, but I like the way you expressed it.

_______________________

Arlington, Va.: Can we expect flooding of the Potomac once all this stuff melts?

Steve Tracton: If we have a heavy rain on warm days before the snow melts significantly, yes, I's expect flooding would be a problem . I do not see this happening 'for a while".

_______________________

Laytonsville, Md.: Happy Snowverkill. Could you explain the term "weather bomb"? Are these predictable or random, unusual occurrence? Can they happen during the summer?

Steve Tracton: Weather "Bomb" is a term coined by my thesis adviser. It refers to an "explosively" deepening storm (rapidly intensifying) by a a set critical rate (at least 1 mb/hr pressure fall over a 12 hour period). These storms are usually very tight (relatively small) and remain notoriously hard to predict. "Bombogenesis" continues to be active area of meteorological research.

_______________________

Alexandria, Va.: So how come we're getting all this, and poor Vancouver with an Olympics to put on, has to truck snow in? Think they'd like some of ours?

Steve Tracton: The large-scale circulation which has been conducive to cold and snow here systematically correlates with the reverse in the northwest.

_______________________

Laurel, Md.: Hey Steve ... Bill B. here. Just about a whiteout here at the moment. Heavy snowband set up north of here and moved down to us (well-depicted on radar). You may get a bit of it down your way in DC/Alex. if it holds together.

Steve Tracton: Bill, thanks for the report. I think it will be close call for DC to feel the major effects of the band you are now experiencing (but don't have time now to look closely).

_______________________

washingtonpost.com: No, the snow does not disprove global warming (Post, Ezra Klein blog, Feb. 10)

_______________________

Alexandria, Va.: Thank you CWG for adding an extra element of entertainment and needed facts to this wacky weather season. We are trying to break out for some skiing at Wintergreen this weekend. One very feisty member of our group wants to leave at 10 a.m. tomorrow. What do you think the road conditions will be like heading south from here, and do you think the decision to pull the plows today will mean that the cleanup will be exponentially slower?

Steve Tracton: I really can't say - depends on local road conditions near Wintergreen - good luck.

_______________________

Steve Tracton: Thanks all for your great questions - sorry I could not answer more. It's been a blast. Stay tuned to CWG for latest on the current storm, including follow up over the next few days.

And, when weather is not the most exiting thing around, remember CWG is always informative and entertaining with articles on a wide variety of weather/climate topics.

© 2010 Washingtonpost.Newsweek Interactive