1/19 - The Roulette Wheel 29 Black Storm - OBS

[jayyy]

NOOOOO you want them to be conservative and then catch up as you are measuring 6" and saying WOW its ripping fatties

You took the words right out of my mouth. I feel like when we’re under a WSW, we either bust low or barely hit the lower range. When they go conservative, we get a pleasant surprise. Maybe those occurrences are just the ones that stick out in my mind but I’m still going with it!!

[AtlanticWx]

so excited to get a daytime snowstorm tomorrow. my sleep schedule has gotten so cooked by the late-night storms that peak at like 4 am. nice to see a snowstorm peaking at like 4 pm 

[psuhoffman]

8 minutes ago, Weather Will said:

Image

well its a rap

[nj2va]

Steadier march down in temps now.  I sat between 32 and 31.8 for about 2-3 hours.  In the last 30 minutes, have dropped down to 30.5, and dropping.

[AtlanticWx]

wtf i didn't realize soundings looked like this

[psuhoffman]

7 minutes ago, psuhoffman said:

This is really late, last 24 hours I've been on the road a lot.  But this would have been pretty much the same map I would have put out last night if I was able too.  Nothing has really changed.  The high or low end of these ranges will depend on banding which will be a nowcast thing.  The little bit of a gap between the 4-8" zones accounts for the little bit of a "jump" that will happen between the initial SW induced boundary wave and the coastal.  4-6" will be way more common in the 4-8" zone but I do think some isolated 8" totals will pop up somewhere in those 2 areas.  As the deform band with the coastal gets going it will cut off the moisture transport to the west and the precip with the initial wave will die.  This does create a bit of a gap, but I don't think it will be nearly as bad as some of the high resolution models were showing.  It's nice that the first threat of both high probability "windows" hit, makes it easier to track if the next few waves miss.  I don't think we are done yet though...as the pattern relaxes I bet we get another wave similar to this to hit.  And it still possible one of the waves this week trends north. 

I could bust low along 95, I do think banding sets up there, but looking at soundings the snow ratios might be really low.  There is a mid level layer that gets a little warm during the heaviest snow, not mix warm but warm enough to inhibit ratios a lot.  Also the VVs don't necessarily align with the DGZ until pretty late along 95.  But...if the ratios end up closer to 10-1 there they could get 4-5" right along 95 easily.  I almost upped that area into the 3-5 but decided to be conservative. 

[psuhoffman]

3 minutes ago, AtlanticWx said:

wtf i didn't realize soundings looked like this

They don't all look that friendly though....

But if the 3k soundings are correct I will bust low along 95, and I won't be shocked if I do. I went low. 

 

[psuhoffman]

9 minutes ago, jayyy said:

You took the words right out of my mouth. I feel like when we’re under a WSW, we either bust low or barely hit the lower range. When they go conservative, we get a pleasant surprise. Maybe those occurrences are just the ones that stick out in my mind but I’m still going with it!!

Over the years I might have verified warning snowfall more times when I wasn't under a warning then when I was...

[IUsedToHateCold]

The others said it earlier: we're starting as rain in the lowlands and then finishing up with a strong backside once the cold air comes in. I don't see any other way for us to get the totals the models are spitting out. The air is already warming. 2-4 seems likely, if it overperforms then up to 6 isn't off the table. 

[Weather Will]

WB 0Z EURO

[RDM]

From the looks of radar, and the lack of returns, it's hard to imagine we're on the eve of a decent event (decent for around here given the past few years of nada).

[psuhoffman]

10 minutes ago, Weather Will said:

WB 0Z EURO

I'm suing ECMWF for stealing my snow map

[psuhoffman]

8 minutes ago, RDM said:

From the looks of radar, and the lack of returns, it's hard to imagine we're on the eve of a decent event (decent for around here given the past few years of nada).

It's not supposed to look like much for another few hours at least...don't spook the usual suspects...we don't need those posts already

[wxmeddler]

0z Euro pretty much aligns with my thoughts perfectly. 18z AIFS nailed my thinking though.

[psuhoffman]

before we start the radar hallucinations...

1am Sim radar

4am sim radar

7am sim radar

10am sim radar

 

[snowdude]

32/30 Stafford, VA

GO COMMANDERS! 

Hoping we get at least 2-3” here! 

[MountainGeek]

This low level inversion is legit -- still hanging at 35/32 at 810ft, half a mile away 500' lower on the river is 32. On up the top ridge it's 38 at 1600ft. 

[pazzo83]

18 minutes ago, MountainGeek said:

This low level inversion is legit -- still hanging at 35/32 at 810ft, half a mile away 500' lower on the river is 32. On up the top ridge it's 38 at 1600ft. 

36 here, 33F about 3 blocks away (and ~150' lower)

[psuhoffman]

[300 square feet]

36/34 in Reston.  Temp has been slowly notching up since midnight.  Not liking the trend.

[katabatic]

3 minutes ago, mitchnick said:

AI 6z run cut back a bit on qpf consistent with other modeling. 

Latest runs also cut back quite a bit on QPF here in the highlands. I also canceled my LES chase this morning as it looks like the bands' forecast continue to inch northward. Not worth the chance of getting skunked for the kind of money airbnb charges. Good news it's still going to snow and the Commanders game was a thrill. 

[Terpeast]

Not a promising sign for south of i-66/rt 50. North of that should still be on track. Gonna be an interesting afternoon

.NEAR TERM /THROUGH TONIGHT/...

Model trends early this morning show Arctic front has slowed
down considerably since yesterday and is not fcst to clear the
northern half of the fcst area until after 18Z. Meanwhile,
models trends and microwave imagery through the snowfall rate
product show precip arriving sooner than previously expected.
Microwave passes since 0220Z showed that snow has been falling
in the mountains since that time and a more recent pass from
0800Z showed that snow, at least aloft, has made it to areas
just west of I-81. Further east, gridded NUCAPS data showed that
925 and 850 mb 0C isotherms are further north than model
guidance suggest and given current temps in the upper 30s and
slower trend on the passage of the Arctic front indicate that
areas along and south of Interstate 66 and US-50 will see more
rain or mixing with rain at the beginning of the precip event.
Still, a 3-hr period of intense precip rates is expected this
afternoon, mainly between 18-21Z, when Arctic air will be
advancing southward. The low pressure system will be out of the
picture by 00Z Monday with most of the snow gone, except in far
northeast Maryland and in the mountains where snow will continue
all night. New snow totals maps were changed slightly,
basically to cut down on snow accumulations some, particulary
along and south of Interstate 66 and US-50 and precip start time
was adjusted to bring precip sooner.

 

[CAPE]

6z  GFS

Nice run but not buying the 5 here.

[CAPE]

35 at 6am

[aldie 22]

34.5 and patiently waiting 

[CAPE]

6z Euro. Looks reasonable. PSU snow map.

[weatherCCB]

Temp up to 36

[Jebman]

28 minutes ago, katabatic said:

Latest runs also cut back quite a bit on QPF here in the highlands. I also canceled my LES chase this morning as it looks like the bands' forecast continue to inch northward. Not worth the chance of getting skunked for the kind of money airbnb charges. Good news it's still going to snow and the Commanders game was a thrill. 

I just can't believe the Commanders. Wow wow wow! 

If they should manage to win this next game..........

[Lucketts]

38/35

[Stradivarious]

Ravens vs Commanders Super Bowl? Maybe…