2/22-23 "There's no way..." Storm Part 2

[TSSN+]

Icon coming on board 

 

[mappy]

2 minutes ago, CAPE said:

The snowfall/depth tools on these models are a joke. Best you can do is use qpf and pick a reasonable ratio and figure it out. 3km NAM has over 20" of snow falling here but a depth of a few inches as the event ends. Thats some hella compaction/melting. Maybe the high winds blew it away lol.

Yeah, I don’t look at them too much. Only shared to reply to snowfan who had mentioned depth. 

[weathercoins]

14 minutes ago, paulythegun said:

Dropped the high end scenarios too

Still pretty absurd that DC is “expecting” two inches with a 15 inch high end - one day out.

[Scarlet Pimpernel]

4 minutes ago, CAPE said:

The snowfall/depth tools on these models are a joke. Best you can do is use qpf and pick a reasonable ratio and figure it out. 3km NAM has over 20" of snow falling here but a depth of a few inches as the event ends. Thats some hella compaction/melting. Maybe the high winds blew it away lol.

Right...there's always a difference between "snowfall" and "snow depth".  Obviously when it's cold, there shouldn't be huge differences, though you can have settling and compacting even in relatively short periods of time.  But it's easy to accumulate a decent amount on, say, grassy surfaces (or a legitimate snowboard), only to have it compact down/melt/whatever and be less some hours later.  All depends on rates with marginal temperatures.

ETA:  And I'm honestly not sure how those "positive snow depth" maps are generated or what algorithm is used.

[Random Chaos]

2 minutes ago, blizzardmeiser said:

Temps will be a problem until the evening 

How? Chesapeake bay running 34F (I measured 33.8F yesterday) and we have a gale warning for winds off the water. Peak surface temperatures for Annapolis area will be held close to freezing from those winds. I don’t see temperatures near the water to be a problem.

[TSSN+]

Icon increased snow across the area by multiple inches. I wouldn’t use that model to make a forecast but seeing it increase is a good sign 

[mappy]

1 minute ago, weathercoins said:

Still pretty absurd that DC is “expecting” two inches with a 15 inch high end - one day out.

So many little things that can boom or bust this forecast. Daytime temps/rates will impact total accumulations before sunset, then where the heavier band(s) set up overnight. It will be easy to get 12” if you’re under the CCB, while dry air will kill snow nearby. 

[NVAwx]

The advisory versus warning areas are obviously taking elevation, temperatures, and climo into account. The norlurn trough is also currently progged to be the western warning (Loudoun, Clarke, Frederick MD, the Blue Ridge, etc.). 

We could have upgrades in the metro area, but for now, that's the best forecast given the melting that will happen. Coastal to the east, elevation to the west. Not unusual.

[Eskimo Joe]

18z ICON goes from 991 mb low off Ocean City at 00z Monday to a 979 mb low east of Cape May by 09z Monday. . . .

[TSSN+]

Rgem also better it just moves out the precip too fast but looks like might be some feed back issues an the mlsp lines are all over the place. 
 

[Eskimo Joe]

Over/under on whether we get an @Ellinwood map?

[WEATHER53]

Possibly by 6pm Sunday  and definitely by 9pm DC will be in a 29-32 degree temp range and that’s not mashed potatoes. 

[LeesburgWx]

3 minutes ago, TSSN+ said:

Rgem also better it just moves out the precip too fast but looks like might be some feed back issues an the mlsp lines are all over the place. 
 

Still loving the location of the IVT maxima

[Interstate]

RGEM still sucks

[Ellinwood]

Just now, Eskimo Joe said:

Over/under on whether we get an @Ellinwood map?

lol I was just making a post when I saw the notification from this one 

Didn't deviate from the NWS much with my forecast... just some tweaks here and there. Won't bother going through the caveats because y'all know them, mainly the marginal surface temps and the lack of good rates inland.

[Paleocene]

Just now, Interstate said:

RGEM still sucks

Good thing that model sucks

[csnavywx]

If you're near or within ~50km to the left/west of the developing 700mb front, BL and ground temps are just not going to be an issue. 2"/hr doesn't care.

 

 

[Keith1174]

24 minutes ago, paulythegun said:

Dropped the high end scenarios too

i think that the high end #'s west of baltimore maybe dropped but it is in increase for baltimore/annapolis and points east.  Bel Air was 18 or 19 earlier and is now 24

[Weather Will]

WB 18Z ICON ticked west.

[Eskimo Joe]

 

 

[J.Mike]

46 minutes ago, mappy said:

Not hiding much but please do try to add more than just all caps posts and holy fck 

Mappy, when does Randy get home?  Looks like I’ll be making reservations at Ruth’s Chris 

[Ji]

Shenandoah Valley triplets approve of both Nams and SREFS and HRRR at this time

I thought you moved to Winchester

[jayyy]

When they go low that’s when we score 

Idc what anyone says.. call it superstition or happenstance.. but this is spot on. Every goddamn time they call for 12+, we flop. Advisories and low end warnings hoisted before marginal events with thumps tend to overperform. Just the way it is.

[mappy]

2 minutes ago, J.Mike said:

Mappy, when does Randy get home?  Looks like I’ll be making reservations at Ruth’s Chris 

I’m not sure actually. We will have to figure out when/where. Maybe somewhere in the middle for us all?

[Maestrobjwa]

21 minutes ago, CAPE said:

The snowfall/depth tools on these models are a joke. Best you can do is use qpf and pick a reasonable ratio and figure it out. 3km NAM has over 20" of snow falling here but a depth of a few inches as the event ends. Thats some hella compaction/melting. Maybe the high winds blew it away lol.

Yeah see this is the part of tracking where I legit get a bit turned around with all these various maps and models and knowing how to estimate where my yard stands. Especially in a marginal setup. Like some are weenie and some are terrible...and the you got the globals still. So for example if the NAME shows 15" how do I mentally turn that into a realistic forecast?

[IUsedToHateCold]

18 minutes ago, Random Chaos said:

How? Chesapeake bay running 34F (I measured 33.8F yesterday) and we have a gale warning for winds off the water. Peak surface temperatures for Annapolis area will be held close to freezing from those winds. I don’t see temperatures near the water to be a problem.

This is one of the rare times the water is helping to keep us cooler out here. If you look at the Weather Underground map of stations you see a 5 degree difference near the water. 

I was out most of the day but I was gonna say we needed the 18z NAM to deliver, and it definitely did. I'm going high end all in. 20 inches for the Nat 20. 
 

[Maestrobjwa]

Bruh look at this mess. That is straight trolling (mind you I'm in Baltimore).

[jayyy]

Flights out for 00z recon! Let’s bring it home

[Interstate]

Still 100% on board with this one.  Never wavered once... I will be sending pictures of 12+ IMBY

[LeesburgWx]

10 minutes ago, jayyy said:

Flights out for 00z recon! Let’s bring it home

This is how you know it’s real