December 29-30 storm.

[Bob Chill]

The nam is just showing another subtle change @ 850 and 500 with a slightly better outcome. We all know what happens if the ns vort pass moves another 75 miles south and the dual low structure becomes one before it moves east of us. NAM isn't there but it could be a sign.

[87storms]

it ended up not looking that great. :less than .25 but starts as snow. I'm less enamored for DC and my house as I think unless we get decent rates, we probably won't see much stickage and it could even turn to rain. This run does have it start as snow and would probably give an inch or 2 our toward Ji and maybe Iad. I've never liked seeing a low to our northwest especially with no real surface high to give us CAD.

neither do i. things looks like they're shaping up out west a little too north for my liking, but i'd be perfectly content with a 2 inch snow to mix to rain.

[MidlothianWX]

DT first guess is out...shooting for 4+ NW of DCA and BWI

[Bob Chill]

I promised myself I wouldn't start doing this so I'll stop here. Just look at the h5 vort panels in the same point in time. 18z on the left. You can see the vort is stronger and further south on the latest run. Still not an optimal pass but put it 100 miles further south and everything changes.

[Ian]

DT first guess is out...shooting for 4+ NW of DCA and BWI

I'm confused what DC is. I guess 2-4"?

[Bob Chill]

I swear this is it...

Look what happens at the surface with that little shift at 500. Surface low to our west is just a bit further south as well. That's the key feature. Wes explained it perfectly. If we want to will this mess to give us a *decent* snow then we need to will the ns vort and surface low about 100 miles or so further south. I'm not smart enough to know what would happen irt to the slp to the south but I can only imagine good things.

[Ian]

I have to hand it to him on the note about locations on a map. Lol facebookers.

[mitchnick]

fyi, I didn't see it posted

12z RGEM at 48 hrs looked d@mn good to me (though 18z out shortly); I know it did well with yesterday's storm wrt cold/snow

http://www.weatheroffice.gc.ca/data/model_forecast/colour_images/12_054_R1_north@america_I_QPFTYPES_t6_048.png

http://www.weatheroffice.gc.ca/data/model_forecast/600_100.gif

[MidlothianWX]

I'm confused what DC is. I guess 2-4"?

I suppose. His map labeling skills aren't the best. I remember with the March '09 storm he had me under an unlabeled black circle. Never quite figured out what that was.

RIC gets the typical mix shaft again. Good thing I'll be up in FDK for this one.

[aldie 22]

Daves map is really aggressive considering the afternoon models

[mitchnick]

Daves map is really aggressive considering the afternoon models

he knows you like aggressive men lol

[aldie 22]

he knows you like aggressive men lol

mitch.....it's the holidays

[Wonderdog]

I swear this is it...

Look what happens at the surface with that little shift at 500. Surface low to our west is just a bit further south as well. That's the key feature. Wes explained it perfectly. If we want to will this mess to give us a *decent* snow then we need to will the ns vort and surface low about 100 miles or so further south. I'm not smart enough to know what would happen irt to the slp to the south but I can only imagine good things.

Bob you literally "willed" the CHILL storm to a stellar performance. It's time again for you to make the vort continue on its southward trek.

[mitchnick]

I look at this wv loop and wonder on the one hand if yesterday's 5h will get out of the way in time and on the other Saturday's system seems to have a lot of moisture to tap

http://www.ssd.noaa.gov/goes/east/eaus/flash-wv.html

[TUweathermanDD]

I look at this wv loop and wonder on the one hand if yesterday's 5h will get out of the way in time and on the other Saturday's system seems to have a lot of moisture to tap

http://www.ssd.noaa....s/flash-wv.html

It does, and thats probably one of the reasons Bob and myself alike expect it to trend wetter up to game time.

[Bob Chill]

I look at this wv loop and wonder on the one hand if yesterday's 5h will get out of the way in time and on the other Saturday's system seems to have a lot of moisture to tap

http://www.ssd.noaa....s/flash-wv.html

uh...,mitch....ummm.....yea.....about the water vapor hallucinations.....you might want to see if your health insurance covers that....

[clskinsfan]

DT seems to think western areas do well again. This is shaping up to be a very good early winter out here. Our one stop light might lose power. In all seriousness. Its not that far to come out and be in the snow. I made the choice to live here for this very reason.

[AmericanWxFreak]

GFS out to 42.. looks pretty good to my weenie eyeballs

EDIT: still looks on the warmer side of guidance. 0c line hanging around DC

[87storms]

DT seems to think western areas do well again. This is shaping up to be a very good early winter out here. Our one stop light might lose power. In all seriousness. Its not that far to come out and be in the snow. I made the choice to live here for this very reason.

it definitely isn't that much of a drive. the xmas eve storm, i didn't need to leave bethesda (was working remote), but was like, i need to see some snow, so i drove up to gaithersburg then towards poolesville. the differences with "not that much elevation" are pretty dramatic. if you're a snow lover, it can pay off living a little further north or west from the bustling cities.

[WinterWxLuvr]

Daves map is really aggressive considering the afternoon models

The HPC has similar thoughts.

[mitchnick]

..and there it is! Put on your 3D glasses.. it looks even better.

lol

it's like clockwork

if you want Yeoman to post, mention the wv

[WinterWxLuvr]

Anybody find any irony in this? From DT storm write up.

[PhineasC]

Daves map is really aggressive considering the afternoon models

I guess they think the models might be too far east or too weak. I have no idea if that is true from a meteorological perspective, but I do know that the models have pulled this act many, many times only to tug back west a little at 36 hours out.

[Deck Pic]

soundings look a bit better too....and it is wetter of course

[TL97]

GFS is good except for the surface we will see if it trends better.

[Superstorm]

fyi, I didn't see it posted

12z RGEM at 48 hrs looked d@mn good to me (though 18z out shortly); I know it did well with yesterday's storm wrt cold/snow

http://www.weatherof...YPES_t6_048.png

http://www.weatherof...ast/600_100.gif

i like the pseudo 50-50 in that map.

[swimmatte]

FWIW

[aldie 22]

FWIW

whoa

[87storms]

fwiw, channel 4 (kammerer) seems to be on board for an accumulating snow in dc.

it's nice that things seem to be trending a little better as we get closer.

[Deck Pic]

SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...

THE NEXT WAVE/LOW CROSSES THE MID ATLANTIC ON SATURDAY.

FRIDAY NIGHT THROUGH SATURDAY...ANOTHER POSITIVELY TILTED LONG WAVE

TROUGH MOVES EAST TO THE ERN CONUS WITH SFC LOW PRESSURE DEVELOPING

ALONG THE GULF COAST AND ISENTROPIC LIFT SPREADING NORTHEAST UP

THROUGH THE MID ATLANTIC. THIS WILL BE ANOTHER SNOWY EVENT FOR THE

LWX CWA...WITH ADVISORY LEVEL SNOWFALL FOR WESTERN BALT-WASH SUBURBS

AND WEST AGAIN. CONSENSUS OF 12Z MODELS IS WITH THE INITIAL PRECIP

WAVE DRIVEN BY ISENTROPIC LIFT WITH MOST CYCLOGENESIS DELAYED UNTIL

EAST OF THE MID-ATLANTIC COAST. HOWEVER...EXACT INTENSITY OF THE

LOW...POSITION OF THE DEVELOPING LOW...AND AMOUNT OF COLD AIR /RAIN

AND SNOW LINE/ IS STILL UNCERTAIN AS OF THIS TIME. NAM IS THE

COLDEST SOLUTION WITH SNOW ACROSS DC...WHILE THE GFS IS THE WARMEST

WITH MAINLY RAIN FOR DC. RAIN/SNOW LINE WILL SLOWLY EDGE NORTH

THROUGH THE DAY. WITH UNCERTAINTY...WENT WITH RAIN OR SNOW WORDING

FOR I-95 AND SOUTHEAST FOR THE MIDDAY AND EARLY AFTERNOON. THE

PRIMARY LOW WILL PREVENT TRUE TROWAL FORMATION OVER THE NWRN

ZONES...SO WARNING CRITERIA LEVELS /5 INCHES...6 FOR OUR WESTERN

FIVE COUNTIES/ IS NOT EXPECTED AS OF THIS TIME. SLIGHT CHANCE FOR

THAT...BUT NOT ENOUGH FOR A WATCH ATTM.