87storms

had some sleet earlier at the clarksburg outlets.  that's about it.  this storm was a day earlier than we needed it.  just not enough cold air to tap into.

actually thought it was raining, but stepped outside and...false alarm.  marginal temps, but maybe we can start out as some frozen once the better stuff moves through.

40 minutes ago, high risk said:

    What'a going on, I think (based off the NAM3), is that you have a huge slug of precip occurring during the evening hours - looks like well over an inch between 00z and 06z when the "snow" really piles up.    The soundings are really, really iffy in terms of sleet potential, but the model microphysics are allowing for some pingers to be mixed in with the rain.     Let's say that we have 1.3" of liquid falling and the model thinks that it's 60% rain and 40% sleet pellets:   we know that would not accumulate, but the tallying does 1.3" x 0.6 = 0.52" liquid of "snow (+ sleet) accumulation".   TT slaps a 10:1 ratio on that and gets 5.2" of "snow", while the Ferrier method will assign a way lower SLR since it knows that the frozen component is sleet and not snow.   

I thought it would calculate the 40% instead. Either way, I can see why the snow maps would be off. This event might be too marginal to toss yet, at least for the northern tier.

edit: nevermind, I think you meant (1.3”)x(0.4). Makes sense 

Should look pretty cool in the morning. Snow is sticking to every tree limb.

Round 2 is adding another coating.

it's hanging around a bit.  successful imo.

got some street stickage with the first band.  a little bit of reenhancement going on.  good enough.

it's a snow shower, thru and thru.  enjoy it while it's here.

car tops are caving

So is the storm gonna end before the advisory begins lol. I’m kidding but it sure doesn’t look like the first band will last too long.

13 minutes ago, DCTeacherman said:

The GFS  has us changing over to snow at 13z-14z Sunday per the precip-type maps on stormvista.   Precip departs between 18z-19z so it supports a period of back end snow, although rather light (<.1 QPF).  Could be some nice snowtv though as the arctic front comes through. 

that's what i'm thinking.  if we can change back over a few hours earlier than the gfs is showing, there might be enough precip to work with to make things interesting.

if the cad stays intact longer and is better than advertised, then the backside of this system could work out.  there's still plenty of precip around when temps start to crash.  it might just be a matter of how far they need to crash to changeover to snow.  i'd be pretty interested in this if i was the northern tier since there's a better chance of the cad holding on longer.  dc/bmore need some work.

shouldn't take too long for flakes to fly given the dews and we currently have an easterly wind.  nam 3k has some better lift moving through right before rush hour, so that could be our start time.

edit: probably close to the end of rush hour, but sometimes these systems move in a little quicker than advertised.  kind of a weak sauce event, but maybe we can get enough steady/moderate to coat things.

looks like the system sped up a bit this run which i don't think is what we want.

air mass in place is pretty good with this, so the low track might matter more in regards to precip than temps.

cmc hints at what's going wrong with this weekend system as it's showing phasing way north with that ns energy.  not sure if that's how it'll work out, but we need this system to stay separated and/or have it lagging behind that reinforced blocking.  i may have some of these details confuzzled, but i think we want a slower overall ss or a trailing wave to start appearing so that we actually have precip to work with when temps crash.

45 minutes ago, losetoa6 said:

For Saturday /....big timing spread 

(12z)

Gfs- Top

Euro

Uk 

 

i think we want slower, so the high building in is out ahead of the ss or at least not lagging behind it.  otherwise, it looks like the storm is finding a weakness and cutting too far west.

7 minutes ago, WEATHER53 said:

This will not cut

i don't know that i buy the cutters, but i think app runner is an issue (though i suppose that classifies as a cutter).  it also doesn't look there's going to be ideal cad developing out ahead of it because of that southeast ridge.  it's a setup worth monitoring, but i could see how it could still be an apps runner even with the favored banana highs over top.

4 minutes ago, Bob Chill said:

Unfortunately there's no mechanism to lock hp over the top. The war let's hp easily slide east as the storm approaches and the hp behind is in a bad position too. Imho- a west track is practically a lock at this point. 

yea i think we'd need this to transfer to the carolina coast or something to make it work.  as is, it's an app runner, though i wouldn't really expect that based off of the high pressure to the north.  they look at least somewhat favorable.

icon really ramps that sunday storm up in the plains.  might need a 1050 high to tame it, ala pd2 lol.

i wouldn't be surprised to see sunday trending a little colder on the front side.

3 minutes ago, nj2va said:

ICON's SLP is south of 12z so its a better run for north of DC especially along the M/D line.  

also interested to see what it does with the weekend system.  pretty close with that, too.

edit: guess i'll need to wait. 6z/18z only goes out to 120.

this last storm is proof that things can change pretty quickly.  one thing that's pretty clear for this area (at least from my view) is that we have a better chance at precip overperforming than cold.  this last storm looked squashy, but we found a way because we've got the gulf and atlantic on our side.  "snow" cold is just not as easy.  for the weekend situation, that high placement looks good in the midwest, but we may need it to be further east.  this last storm we had a stout high tracking over top in unison with the southern stream.

looks like another band forming and headed towards mby.

8.5" here, unoffically.

This is overperforming like some of our recent rainers. Double digits are in play if these rates continue for a couple more hours.