March 13/14th Storm Thread (Storm Mode)

[nj2va]

18z JMA is a huge hit for DC. About 1.5-1.6" all snow. 850s and surface stay below freezing though 850s get close in the height of the storm. 

Its on the western edge of guidance as it develops a low over the eastern border of VA/NC but takes it NE from there to a 989 about 100 or so miles off the Delmarva. 

[Roger Smith]

That activity in the western Gulf of Mexico continues to look somewhat promising and has extended more east than southeast against the guidance suggestions, no real organization to it yet but given that the GFS improved without drawing any energy from that feature at all, I am very optimistic that it could lead to further improvement of the coastal vs inland energy balance if it can continue to make eastward progress enough to keep up with wave developments over the inland southeast. 

The earlier strong wind gusts were likely thunderstorm produced but there continues to be convergence of wind fields south of TX-LA with a potential low running e.n.e. from 29N 92W to 31N 85W. This would really anchor storm development and force the ULL to do no further meddling and play ball with the coastal. 

[dukeblue219]

36 minutes ago, AlaskaETC said:

TV mets love to use it because they get the full suite for free. It's made by a private company (WSI) and it's pretty much a unspoken rule that TV stations use it almost exclusively.

Isn't the RPM the model that some local TV stations re-brand as their "in-house" model? I always found that designation particular silly. No, WBBQ from Anytown, USA does not have their own weather model that's worthy of comparison to the GFS or Euro  

[Bob Chill]

2 minutes ago, WxWatcher007 said:

That tamping down had been a regular occurrence this winter and I think it's killed us a few times. I said the other day I expected amped runs that would torch us to wobble backward toward a sweeter spot. Track seems good for us, now hopefully we can hone in temps and qpf. This weeks ups and downs have been fun.

Through years we've had many storms where we got crushed in the mid range and then everyone immediately sets their bar there. Then have a hard time enjoying a 4-8/6-10" storm when guidance gets a grip on reality. Lol. 

Being solidly in the game inside of 72 is always a great feeling. At least for me anyways. 

[PhineasC]

Glad to see good precip extending SW. That all ends up in MBY eventually. I know there is a kind of myth that "NE MD" can cash in on Miller Bs that are screwing DC, but that is usually just model fantasy of wrap-around and bands developing overhead. It rarely pans out. A slug of moisture coming up and nailing DC is always a better bet.

[yoda]

7 minutes ago, nj2va said:

18z JMA is a huge hit for DC. About 1.5-1.6" all snow. 850s and surface stay below freezing though 850s get close in the height of the storm. 

Its on the western edge of guidance as it develops a low over the eastern border of VA/NC but takes it NE from there to a 989 about 100 or so miles off the Delmarva. 

18z JMA meteogram for DCA -- http://meteocentre.com/numerical-weather-prediction/meteogram.php?stn=Washington&mod=jma&run=18&var=std&lang=en&map=us

Around 40mm total QPF which equals 1.6" QPF as you said

[Ian]

32 minutes ago, Bob Chill said:

My theory proved correct. Gefs mean supports the op and got better for a lot of folks to the west and southwest. Most importantly it got better for my yard. And Matt and Ian and randys. 

 

I'm on phone so if someone can post the 12z and 18z panels it would be appreciated. 

I'm torn because 7.1 at DCA would hit my seasonal so I can't root for much more than that. That could be like 12 here tho. 

[Bob Chill]

2 minutes ago, WxWatcher007 said:

I'm talking about the two short range fails we had this season but yeah, there are very few times where you can just lock up your warning event outside like 48 lol.

The expectations game is a brutal one. I'm hoping to fully endorse this one soon  

I know it doesn't really seem on the table, but would a "clean" phase slow this down once it begins to bomb out?

We're too far south for a clean phase bomb at this point imho. We would need the ns low to die off in KY to get the brunt of a clean phase. 

But the inv through type of enhancement that the 18z gfs showed is pretty ideal. I would guess that the ukie, jma, icon, etc are doing something similar. Loop the NE region vort panels on TT. You can see why the precip field expanded west. The ns low dies fairly quick bit the southern energy gets a nice tug at the right time. Upper levels looked really good overhead as it ramps up. 

[Bob Chill]

This is the pretty panel. Look at the axis on the southern vort. It's pointing towards 10-11o'clock and energy overhead. A lot of good stuff happening upstairs right there 

[psuhoffman]

38 minutes ago, Bob Chill said:

My biggest worry the whole time has been a mostly rain storm. My second biggest worry was weak sauce rates in general. You know I want a bomb like everyone else. But if we've had every med range bomb verify our climo maps would need to be re-written. They tame down in the short range quite often. 

0z is the official kickoff to the short range. I like what I see right now. My yard may actually survive a disaster. Hopefully tomorrow things juice back up we get the better of both worlds. A cold snowstorm in mid march. The storm is currently progged to move to fast for anyone anywhere to get a historic storm except maybe a small area or too. 

Yea the majority of the precip falls in less then 12 hours. There will be light stuff lingering with the upper low for a whole after but 90% in not all of our accumulations will come with the overnight thump. So I was always skeptical of the 20"+ totals. But we have seen plenty of historic examples of quick 12-18" thumps to think that could happen.  It's a hard get but not impossible. In some ways I enjoy a quick 12 hour heavy thump snow of 10-15" as much as a longer duration bigger storm that involves dry slots and banding and all that crap. 

On the other hand I would be wary of a less dynamic event ending well. Since this is only a 10-12 hour window if it doesn't snow hard not only would the thermals become a problem but we're not seeing big totals in only 10 hours of snow if it's not heavy. The speed and time of year necessitates this be dynamic.  Things seem to have stabilized today and we still are in the winning side of the bell curve on that equation. 

[SomeguyfromTakomaPark]

1 minute ago, psuhoffman said:

Yea the majority of the precip falls in less then 12 hours. There will be light stuff lingering with the upper low for a whole after but 90% in not all of our accumulations will come with the overnight thump. So I was always skeptical of the 20"+ totals. But we have seen plenty of historic examples of quick 12-18" thumps to think that could happen.  It's a hard get but not impossible. In some ways I enjoy a quick 12 hour heavy thump snow of 10-15" as much as a longer duration bigger storm that involves dry slots and banding and all that crap. 

On the other hand I would be wary of a less dynamic event ending well. Since this is only a 10-12 hour window if it doesn't snow hard not only would the thermals become a problem but we're not seeing big totals in only 10 hours of snow if it's not heavy. The speed and time of year necessitates this be dynamic.  Things seem to have stabilized today and we still are in the winning side of the bell curve on that equation. 

Is there any chance this thing slows down at all? If so, what mechanism would make that happen?

[packbacker]

42 minutes ago, Bob Chill said:

Through years we've had many storms where we got crushed in the mid range and then everyone immediately sets their bar there. Then have a hard time enjoying a 4-8/6-10" storm when guidance gets a grip on reality. Lol. 

Being solidly in the game inside of 72 is always a great feeling. At least for me anyways. 

Good luck to you guys...I know you guys haven't had squat this winter.  You have several different models handling the pieces of energy subtly different and they all show a very good winter storm for most.  That in itself could be an ensemble mean.  Hard to beat the Euro/EPS inside day 60 hours...and GEFS agrees.

[PhineasC]

2 inches seems grossly low for the cities given all of the guidance we have. With this coming overnight in a cold airmass it doesn't matter that it's March. Night is still as dark in mid-March as it is mid-January.

[Eskimo Joe]

There goes the watch.

 

 

[stormtracker]

000
WWUS41 KLWX 120052
WSWLWX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
752 PM EST Sat Mar 11 2017

DCZ001-MDZ003>006-011-013-014-503>508-VAZ027>031-039-040-051>055-
501-502-505>508-WVZ050>053-055-120900-
/O.NEW.KLWX.WS.A.0003.170313T2300Z-170314T1800Z/
District of Columbia-Washington-Frederick MD-Carroll-
Northern Baltimore-Southern Baltimore-Prince Georges-Anne Arundel-
Northwest Montgomery-Central and Southeast Montgomery-
Northwest Howard-Central and Southeast Howard-Northwest Harford-
Southeast Harford-Shenandoah-Frederick VA-Page-Warren-Clarke-
Madison-Rappahannock-Culpeper-
Prince William/Manassas/Manassas Park-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Northern Fauquier-
Southern Fauquier-Western Loudoun-Eastern Loudoun-
Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Hampshire-Morgan-Berkeley-Jefferson-Hardy-
752 PM EST Sat Mar 11 2017

...WINTER STORM WATCH IN EFFECT FROM MONDAY EVENING THROUGH
TUESDAY AFTERNOON...

The National Weather Service in Baltimore MD/Washington has
issued a Winter Storm Watch, which is in effect from Monday
evening through Tuesday afternoon.

* PRECIPITATION TYPE...Snow.

* ACCUMULATION...Potential for 5 or more inches of snow within 12
  hours. Some locations may see significantly higher accumulation.

* TIMING...Snow will overspread the area Monday evening and
  persist into Tuesday.

* IMPACTS...The heavy snow may make many roads impassable and may
  produce power outages due to the weight of the snow on tree
  limbs and power lines.

* WINDS...Northeast 10 to 15 mph with gusts up to 25 mph.

* TEMPERATURES...In the lower 30s.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is a potential for significant
snow, sleet, or ice accumulations that may impact travel.
Continue to monitor the latest forecasts.

&&

$$

Jackson/Rosa

[Eskimo Joe]

LWX AFD for posterity

https://mesonet.agron.iastate.edu/wx/afos/p.php?pil=AFDLWX&e=201703120058

[Thanatos_I_Am]

Clear in the watch they are noting the possibility of much higher accumulations. Never seen that before. Shows how Volatile the guidance is.

[Wonderdog]

1 minute ago, Thanatos_I_Am said:

Clear in the watch they are noting the possibility of much higher accumulations. Never seen that before. Shows how Volatile the guidance is.

It's been done a number of times in the last few years.

[Thanatos_I_Am]

Just now, Wonderdog said:

It's been done a number of times in the last few years.

Specifically where they mention the idea of "significantly higher accumulations"?

[yoda]

1 minute ago, Wonderdog said:

It's been done a number of times in the last few years.

Really?  I haven't seen language like that in a while

[WinterWxLuvr]

2 minutes ago, Wonderdog said:

It's been done a number of times in the last few years.

 

1 minute ago, Thanatos_I_Am said:

Specifically where they mention the idea of "significantly higher accumulations"?

I've never seen that language.

[Eskimo Joe]

LWX added the "power outage" and "significantly higher amount" wording.  Don't see that too often.  Still need the straight flush at 00z before we even consider popping champagne.

[BTRWx]

13 minutes ago, PhineasC said:

2 inches seems grossly low for the cities given all of the guidance we have. With this coming overnight in a cold airmass it doesn't matter that it's March. Night is still as dark in mid-March as it is mid-January.

What did I miss to have to say that?

[PhineasC]

1 minute ago, BTRWx said:

What did I miss to have to say that?

Some random DC TV talking head someone posted about. 

[osfan24]

FWIW, Bernie Rayno is ultra conservative and did a periscope video earlier today and said he sees a good shot at a foot or more up 95 from VA to NE. He also said he thinks someone could get two feet, but mentioned he didn't think it would be DC, but he wasn't really ready to go there yet because he wants study things more as gametime gets closer. I thought that was really bullish from someone who routinely throws out relatively low snow totals in some of our biggest storms of the past.

[stormtracker]