"thundersnow"! wow.

Heading off to the store for milk, bread and TP.

Not to jinx the event, but finally something to look forward to.

What are everyone's thoughts about possible afternoon activities being canceled for Fairfax and Arlington? (for any metro area county basically)

@Curmudgeon4 -- hah! I did that yesterday. Today and tonight it'll be all about getting pictures.

Hell of a time to be a CPA... :(

The radar this morning is very interesting. I read over on Eastern WX that these initial bands that are setting up could indicate where the back edge of the precip will be for the main event. Currently the western most light band is over western loudon county extending southwestward. there is another band beginning to form over fairfax county but this is NOT were the back edge will be in my opinion.

Interesting to say the least.

jason (and other experts):
am i correct to say there will be no "changeover" to rain/sleet etc...on monday - it stays all snow? will it start as snow?

Snowing in Bethesda!

DCA totals often seems to come in low, so i'm sticking with 8"-12". I wouldn't be surprised to measure 14" in my backyard (5 mi from the airport), while DCA reports 8" only officially.

Heavens! I have been extremely lax in checking CW this weekend, and just signed on to see this snow headline!!! I almost stopped breathing! I had to check to make sure it wasn't April 1! SNOW! Glorious snow in DC!!!

Ok, i think i'm okay now. but, i am pretty friggin' excited. :-) luckily, we bought milk and toilet paper yesterday.

I'm happy that we have stationary snow showers in our area now. It's keeping the atmosphere moist for when the main storm arrives later. I hate seeing the first few hours of a snow storm missed due to evaporation in dry air (virga). I'm also wondering if these snow showers will mark an axis of heavy precipitation with this storm, or perhaps just the western edge of the snow. Any comments Jason?

@walter-in-falls-church

I'm not seeing a changeover risk...although folks east of I-95 could mix with sleet at times.

I don't even remember what a good snowstorm looks like in D.C. I'm psyched for this one! Got about 1/2" last night on cars/grass.. still a little hanging around. Keep a watch on the boundaries in the area still causing snowshowers this morning, wherever the deformation band sets up on this storm could get a nice big wallop of snow.

Guys, I've got a question. I haven't checked Capital Weather since last Monday. Uhm...did this storm come out of nowhere? I didn't hear anything about until right now when I logged on. I didn't hear anything from the local mets either, but have you guys been tracking this storm since last week or?

Wow, check out the radar! This thing looks like a hurricane once it has come inland.

http://radar.weather.gov/Conus/southeast_loop.php

@Kevin, CWG and jfva

I also saw the discussion about the current snow band orientation serving as an axis for snow to develop and also serving as a western boundary for the heavy snow. I haven't seen research to support this, but intuitively it makes some sense. However, I would think the precip would expand west at least some as the main slug of precip to the south lifts to the north and northeast.

@Rafael

We first mentioned the possibility of some wintry weather over the weekend on Tuesday. We started to see some real potential Thursday, did a Snow Lover's Crystal Ball on Friday, and started to sound the alarm bells with our post early Saturday a.m.

HAHAHAHAHA I knew we were due. IM lovin this

yeah, raphael, these guys were WAY ahead of the tv weathermen. they're way better.

Listen, wet blankets, bob ryan's doppler 5000 is NEVERRR WRRRROOOOONNNNGGG!!

Also 2 words:

TOPPER.
SHUTT.

Thanks Jason. I figured that. I'm surprised we might get some decent snow out of this. We were due.

you know, i'm sure the tv weathermen are mostly good meteorologists. they've just got so many non-weather concerns. they probably miss doing real meteorology like the capwx people get to do.

CWG-
I was reading where during the storm the winds will really be picking up with gusts to 40 mph overnight. What are the chances that our Winter Storm Warning will be upgraded to a Blizzard Warning?

Question: Though the NAM and GFS models seem to have the storm tracking off towards the east and just skirting DC, since there are no areas of high pressure near this low, will it have more of a chance of tracking on a more northeast direction? If so, can we expect more moisture to be pulled off the Atlantic for heavier snow totals?

Bdeco, nice radar link. We're going to love being on the cold side of this one. BTW, "storm #2" light snow now falling in the District.

light snow for the past 30 mins here in shirlington

It's been struggling to maintain snow for a while here now in Columbia. Rain's been sneaking in and out. Everything seems to have stopped for the time being though. Had nearly an inch on the ground when I woke up. Now it's patchy cover at best.

very light flurries at the Vienna metro. Woohoo!!!

@scubadiver

Think chances they'll upgrade to a blizzard warning is unlikely because the winds will become strongest as the snow is winding down, but won't rule it out.

@altruisticone

Snow totals would be enhanced over the DC area if there's a slight westward wobble in the track...but it works the other way too (wobble east, less snow).

I am coming to get you, DC!

Rarrrrrrrr!

Cloud cover has thinned, and with the fairly high sun angle temps have really jumped. Wouldn't be surprised if some areas rose up into the 40s this afternoon.

This will help warm the pavement, slowing the sccumulation of snow on major roadways.

That should be "accumulation"! LOL

So what are the chances of us getting some thundersnow?

Friends in Kennesaw, GA (NW suburb of Atlanta) are reporting thundersnow right now.

If what we're getting down here in Charlotte is any indication, expect heavy convective snow. We've had over an inch of cold rain since just before daybreak. In the past 30 minutes the rain mixed with hail (not ice pellets or graupel--real convective hail). This could be the winter version of a training event of thunderstorms, people in the path of the heaviest storms will get serious accumulations.

Curmudgeon: Clouds are thickening up quite nicely:

http://www.intellicast.com/Local/Map.aspx?location=USVA0659 (turn on the satellite layer to see cloud cover)

And temps are only in the low thirties. I can't see them climbing much higher, especially since the wind is starting to come from the NNE.

From reports, look of the radar, and the dynamics with this storm, I would say moderate risk of thundersnow (50% chance).

12z GFS shows 10.5 inches for Dulles

http://weather.hopto.org/snow/kiad.txt

I am totally amazed that it ever snows in the D.C. metro area, given all the hot air blowing out of the District from those lobbyists, legislators, policy institutes, etc.

Up to 39 in Frederick, MD, and 36 this hour at DCA.

Curmudgeon, I think you're giving the whole "sun angle" argument more credit than it really deserves on March 1st. This time of year, storm dynamics still play a much larger role. Cold air advection with this system should be more than adequate for accumulating snows. Example: In 2002 On May 18, after several days of temperatures well into the 60's Oneonta, NY (only 4 degrees north of DC and 2+ months later resulting in a higher sun angle) received nearly 4 inches of snow on graduation day.
So, while sun angle is the most dominant feature in heating the earths surface in the long term, in the short-term spans such as hours or even a few days, it doesn't have the same impact.

Heading off to the store for milk, bread and TP.

Posted by: Curmudgeon4 | March 1, 2009 11:09 AM

-------------------------------------------

Don't forget the eggs and brownie mix. Did our shopping yesterday. Just got done going to Tractor Supply for bird seed and filling up the bird feeders. We're ready.

BRING IT ON!

@Curmudgeon--

The sun angle will be no match for the snow intensities possible with this storm. Could be pretty extreme.

capwx:
should i be concerned that it's 39 degrees here? will it get cold "ahead of the storm" or might we start as rain?

Current temp. in Burke: 38.5 with overcast skies.

I'm hurried about the temperature outside, it's well above freezing. I'm scared it's going to affect the snow totals.

Sun angle is a big player right now. Thin coverage in the overcast has allowed temps to jump...the dusting of snow that we had on the ground disappeared very quickly. And as I mentioned last night the incoming solar radiation is going to warm the pavement.

Still thinking some areas are going to jump into the lower 40s this afternoon.

Well... now I'm glad that I brought work home on Friday even though I felt ridiculous since it was like 65 degrees outside.

Is it safe now to do happy snow dances in my living room? ;-)

Brian is correct that sun angle is frequently overrated. The March daily snowfall record was set on the 29th of the month. The dynamics of this system are such that it literally "manufactures" its own cold air.

the sun angle will not be a factor in this storm. First of all, the snow will fall at night. Secondly, snow intensities will be high enough to negate any potential sun factor. There is also no reason to worry about temps. once the precip starts, temps will drop off rapidly.

Radar looks beautiful to our south!!

Just got back from a quick trip from Merrifield to my office in Ballston. I didn't see even one plow or salt truck on the (admittedly short) sections of routes 66 and 495 on which I traveled. If the temps drop quickly enough to freeze up the wet roadways, and snow quickly becomes heavy, NoVA will have an enormous travel nightmare on its hands. Where is VDOT???

Wait, don't answer that....

Dont worry about the temps. There is a huge 1040 low over the great lakes and when this sucker rides up the coast all that arctic air will pour in. It will be in the upper 20's early this evening and probably won't break 30 again till Wednesday afternoon.

With a storm like this, it will take care of itself. 100% snow.

It would be too, too cruel to get us all excited for some real snow only to have it fizzle at the last second.

I am a tad worried about the 39 temp I have right now. But, then I found out there is a major global warming rally scheduled for tomorrow. That always gives me hope for a big snowstorm.

Sorry, that was a 1040 high

Temps must be higher to the north and west? It's still only 33.5 in NE PG County.

Aha! The day of reckoning for you snow abundant westerners has finally come. You get rain and we get snow! :)

Just starting to see some very light snow in Loudoun, just west of the RT 7/RT 28 interchange.

capitalclimate, jfva, jpl1019,
thanks for the reassurance re; temps. i love a storm that takes care of itself!

Curmudgeon - FWIW, I agree with you. Was just out and the thin cloud cover DID allow rapid melting. I'm at 39 right now in Ashburn. I think totals will be cut down slightly, though not much, due to initial melting.

But, then again, I don't wear snow goggles either.

Areas to in central VA going to get slammed. See this special statement for potential for convective/thundersnow.

The rule of thumb for federal closures is that eight inches must fall, correct? Is that the "official" snow depth at which Metro shuts down?

SnowMonster & others:

Read all about it from metro

http://www.wmata.com/getting_around/safety_security/snowmap.cfm

Jason will probably say that I was remarkably evenhanded in my climate class and had fun with forecasting. He's a real natural, BTW.

1. Anyway BEWARE THE DDS (Dreaded Dry Slot) that appears to be developing behind the convection in NC/SC. It looks like it is going to track a bit east of DC.

2.The packing on the NMM is amazing. If you really go with the models you have to go 10+ in NE DC down to about 4 as close as Dulles.

3. All bets off on totals if thundersnow makes it in. Some places that get it will hit 15. DC will be on the absolute western margin of that.

Pat Michaels
Cato/UVa

4. I'm in downtown. Put me down for 6 +- 1. I cant buck all those models.

can someone explain to me exactly what thundersnow is exactly? i understand the main idea, but how is it caused etc.?

Based on past experience, Metro hasn't closed outside stations unless it's greater than 8 inches areawide. That seems unlikely for this storm. The Fed will be open tomorrow, count on that.

Liberal leave likely.

Fenty declared a snow emergency, beginning at 4

Sorry folks another year without good snow storm.

The dew point is 30%, temperature is 36% in Falls Church. VA.

The "bulk" of this moisture is gonna be most impacted south of the DC area if at all in the form of sleet and cold rain.

I have yet to see the colder air moving in to the area, too late, dew point is rising, along with humidity, but not enough to support snow fall, sorry.

It's 2 PM and the half this area of the low pressure is already half way off the coast.
If any one get significant snowfall amounts it will be around Wilmington, Delaware, NE of Baltimore.

Sorry, I want a good snow storm myself but the cold air is not in place, the low pressure is already off the coast. Dew points are marginal at best and the temp when meets with the dew points will at least very most support some sleet & very cold rain.

Unless it does a "negative tilt"

I've got to work and luv driving in it, got front wheel drive but this year 60% chance it wont happen in the DC area.

I'm a little 45 yr old kid at heart.

buncetm,

I would reevaluate your storm analysis.

I want some of whatever bunce is smoking.

Had more thunder past hour in Charlotte, precip lifting NE, temp 34, baro 29.67 or 1004 mb. Snowing in Hickory, NC about 35 miles NW so the changeover is starting down here. In addition to the convective element, expect strong winds. Last hour steady NE 24 G 33, can imagine that winds may be stronger in DC as system intensifies.

I enjoy how buncetm thinks that he's more intelligent then CWG AND the NOAA.

Or maybe that's just my "please snow! SNOW!" mentality being snarky.

Uh oh. Does this mean the Capitol Climate Action is going to be canceled?

http://www.capitolclimateaction.com/

Hi Pat, thanks for weighing in! Jason once told me a few years ago that when you make a snowfall forecast, we need to pay attention to it! You've got a solid track record with D.C. snow events. Your thinking on this one is pretty much in line with ours. There will be a lot of nowcasting as the heavy snow bands set up (assuming they do...) and any thundersnow develops. Very impressive dynamics with this system. We'll be utilizing new tools, such as Twitter, for the nowcasting, as well as this site of course. Check back with us later as things evolve.

Current temp in Burke: 39 exactly with overcast skies.

buncetm:

What in the world are you talking about?
It doesn't look the low pressure system is halfway off the coast on http://www.goes.noaa.gov/ECIR4.html.

@buncetm

http://www.threadbombing.com/data/media/2/samuel_L_Jackson.gif

Slightly off topic: As Hugh mentioned, the large climate change event tomorrow is going to appear quite ironic, with thousands of protesters expected to show up at the Capitol's coal-fired power plant. Snow, even if it is no longer falling, may not make the best backdrop for a global warming protest! Of course, one snowstorm does NOTHING to change long-term climate trends, but it can damage public relations for activists. Why didn't they schedule this for spring or summer?

In the typically "unshaded" areas, last night's snow is but a memory in my backyard here in Ashburn.

The thin cloud cover and temps in the upper 30's work quickly this time of year.

Andrew, CWG: Please publish your Twitter info so we can follow. Thx!

OK, Washington, please follow President Obama's lead and go without overcoat or hat tomorrow. We need to show the rest of the country our flinty resolve!

36.2 here in Sterling at the moment. The sun is poking through the clouds; most of the snow in unshaded areas has melted. I'm hoping - praying - that I'll be far enough away from the western edge of the system that I will see upwards of six inches.

I'm under the impression that bands will cause locally greater snow totals.

On a side note, it's been a bit breezy for the past half an hour. Maybe temps will begin to fall.

Hi ~sg -- See Twitter information via link at top of post.

Gotta say, I love how Dr. Hansen called for all citizens to protest at the Capitol Hill coal power plant tomorrow when we may have 6+ inches of snow on the ground. Like Andrew said, it doesn't mean anything to long-term trends, but they're going to end up looking like fools. Then again, serves him right for mixing politics with science (and for using isolated weather phenomenon as evidence of global warming).

Crossing my fingers that the western cut-off for this storm is west of Bethesda! Hate it when PG county gets more snow than moco...

Snow wall advancing up the potomac... looks like it's going to enter into D.C. around 4ish.

its 3 and still no snow? issit coming soon or should i give up? :\

Still waiting for the first of it here in Springfield...

strangldangel:

Give it time! Just got a call from a friend in Fredricksburg and its snowing pretty good down there, Snow wall is moving north/northeast.

NOAA just upped the totals for C'ville to 5-10; 1-2 this afternoon, 4-8 tonight. Strikes me as a bit odd given we're so far west and a dry pocket has enveloped us for most of the afternoon.

Keeping my fingers crossed.

Light snow & 34 in NW Spotsy.

I work for the Federal Govt in DC. We probably won't have a snow day off with Obama now President. He is used to Chicago winters and thinks we here in DC are wimps dealing with snow.

what is cville?

Just started snowing on Broad Creek (by Mike's Crab House) in Annapolis, 37 degrees.

snoinmclean, c'ville = Centreville VA (I think!).

Cville = Charlottesville

Spotty snow here, and still quite warm at 36.

I personally think that temperatures will drop quite quickly once the snow begins; moderate snow should bring temperatures in the mid (and even upper) 30s in many places to near the freezing mark an hour or so after the snow starts in earnest (meaning more than flurries), and most likely below freezing not that long thereafter.

Can anyone in and around areas to the south and east of DC, like White Plains, La Plata, Stafford, let us know what type of precipitation is falling there right now and at what intensity? Radar echoes look relatively impressive...

CWG, is the center of this activity where you thought it would be at this time of day or has the storm overall shifted in any direction...E/W?

not as far south as White Plains...but down by the fort (ft washington) it was 37 a few minutes ago and light rain/drizzle.

Re Capitol Hill demonstration (nlcaldwell & others):

This Just In: Irony Not Dead
Blog Reports Winter Not Yet Over!

I may know little about meteorology, but I have been observing DC weather since the days that the weathermen on the local news (no women in early days) used to place felt clouds on a board--sometimes they'd fall off--or draw pictures. I have to agree with curmudgeon4 and bunceton, but perhaps for different reasons. The storm looks too moisture laden and moving too fast for this to be a major storm. The cold air won't turn the moisture to snow east of DC. A couple inches and closed schools to the west of DC and all rain east and south of PG county. Every year a storm gets hyped up and turns out to be a dud, and this may be the one for this year. But I love snow, so if I'm wrong I'll gladly eat my hat.

just checked outside and there is a light mix falling in Ft Washington...still at 37.

Wet Bulb temperatures are near or actually above freezing. Going to take awhile for surface temps to fall below freezing, unless we get some real heavy precipitation.

Still time to make that last minute dash for the "Three Essentials"...milk, bread and TP!

Light rain/drizzle mixed with a few flakes in Oxon Hill, MD.(National Harbor) Temp. 37.2

Snow in Bristow and starting to hold on to the grassy areas

In Stafford, VA:
It's snowing and has been for awhile (originally the big fluffy stuff, now the fine stuff). The sidewalks are now starting to coat and the streets are getting slick. Temp is 33.

I dont know about you guys but it looks like it is breaking apart to the south.....Now Im not a weatherman But it looks to me like we might get an whoppen inch in Bristow..This is killing me....Im from Wisconsin and this is not a winter storm!!!!!!!!!!

What happened to every body????? All the weather guys are quiet?????? Did we give up on this storm now too??????

Why does it seem like almost every time we get a prediction between X and Y we end up getting less than X? I'm serious. If in the rare occurance the prediction is correct, we still generally get at the low end of the prediction.

I understand the nonlinearities and variability associated with predicting the weather but I do not understand how our snow totals are almost always lower than the lowest of the predicted range.

After living in DC for 15 years, I can say I don't remember a single time where the meteorologists' predictions were too low.

Are they over-predicting for public safety reasons?

It really seems like a cruel joke they play time and time again on snow lovers. Am I the only one who has noticed this?

The only thing I ask is a little of honesty out of the local meteorologists.

If we might only get an inch but we could get a foot then say 1-12". If it might be just rain then say 0-12". Crap, you're given freedom to give a range to begin with. Use it.

I can understand if you give a range in the 10-90th percentile. Give yourself a 10% chance to be wrong on each end. But, gosh, it seems like your giving us a 50% chance of being wrong on the low end and a 99% of being wrong on the high end.

BTW, my brother is a meteorologists for the NWS so I am familiar with the complications of predicting the weather.

Yes, I am bitter. After hearing the same story 20 times in a row it gets old.

Yeah, everybody pooped out, just like the storm. So far. Annapolis area has about 2" on the ground so far. Underwhelmed, eh?